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Monoterpene (−)-citronellal affects hepatocarcinoma cell signaling via an olfactory receptor
Abstract
Terpenes are the major constituents of essential oils in plants. In recent years, terpenes have become of clinical relevance due to their ability to suppress cancer development. Their effect on cellular proliferation has made them promising agents in the prevention or treatment of many types of cancer. In the present study, a subset of different monoterpenes was investigated for their molecular effects on the hepatocellular carcinoma cell line Huh7. Using fluorometric calcium imaging, acyclic monoterpene (-)-citronellal was found to induce transient Ca(2+) signals in Huh7 cells by activating a cAMP-dependent signaling pathway. Moreover, we detected the (-)-citronellal-activated human olfactory receptor OR1A2 at the mRNA and protein levels and demonstrated its potential involvement in (-)-citronellal-induced calcium signaling in Huh7 cells. Furthermore, activation of OR1A2 results in phosphorylation of p38 MAPK and reduced cell proliferation, indicating an effect on hepatocellular carcinoma progression. Here, we provide for the first time data on the molecular mechanism evoked by (-)-citronellal in human hepatocellular carcinoma cells. The identified olfactory receptor could serve as a potential therapeutic target for cancer diagnosis and treatment.
Copyright © 2014. Published by Elsevier Inc.
... The following primary antibodies were used: custom-made affinity purified rabbit IgG polyclonal antibodies against OR1A2 or OR2AT4 (Eurogentec, Seraing, Belgium). The specificity of both antibodies has been shown before by detecting heterologous expressed rhotagged ORs in Hanna3A cells (Busse et al. 2014;Maßberg et al. 2015). For validation of our results we used a commercially available anti-human-OR2AT4 polyclonal antibody (Thermo Fisher Scientific cat: PA5-71599) and a comercially available anti-human-OR1A2 polyclonal antibody (Thermo Fisher Scientific cat: PA5-99907). ...
... To identify functionally expressed ORs in primary human AM, Ca 2+ imaging was used because previous studies showed changes in intracellular calcium concentrations after stimulation of ectopically expressed ORs Maßberg et al. 2015;Manteniotis et al. 2016b). We tested five known agonists for commonly expressed ORs (Helional, Sandalore, Brahmanol, Citronellal, and Citronellol) as well as two OR agonists secreted by respiratory bacteria (Methylcyclohexane and Heptane) (Abd El Qader et al. 2015). ...
... All increased intracellular calcium concentrations (Fig. 1). Sandalore and Brahmanol are ligands of OR2AT4, while Citronellal is a ligand of both OR1A1 and OR1A2 (Busse et al. 2014;Maßberg et al. 2015;Schmiedeberg et al. 2007). ...
Background
Therapeutic options for steroid-resistant non-type 2 inflammation in obstructive lung diseases are lacking. Alveolar macrophages are central in the progression of these diseases by releasing proinflammatory cytokines, making them promising targets for new therapeutic approaches. Extra nasal expressed olfactory receptors (ORs) mediate various cellular processes, but clinical data are lacking. This work investigates whether ORs in human primary alveolar macrophages could impact pathophysiological processes and could be considered as therapeutic targets.
Methods
Human primary alveolar macrophages were isolated from bronchoalveolar lavages of 50 patients with pulmonary diseases. The expression of ORs was validated using RT-PCR, immunocytochemical staining, and Western blot. Changes in intracellular calcium levels were analyzed in real-time by calcium imaging. A luminescent assay was used to measure the cAMP concentration after OR stimulation. Cytokine secretion was measured in cell supernatants 24 h after stimulation by ELISA. Phagocytic ability was measured by the uptake of fluorescent-labeled beads by flow cytometry.
Results
We demonstrated the expression of functional OR2AT4 and OR1A2 on mRNA and protein levels. Both ORs were primarily located in the plasma membrane. Stimulation with Sandalore, the ligand of OR2AT4, and Citronellal, the ligand of OR1A2, triggered a transient increase of intracellular calcium and cAMP. In the case of Sandalore, this calcium increase was based on a cAMP-dependent signaling pathway. Stimulation of alveolar macrophages with Sandalore and Citronellal reduced phagocytic capacity and release of proinflammatory cytokines.
Conclusion
These are the first indications for utilizing olfactory receptors as therapeutic target molecules in treating steroid-resistant lung diseases with non-type 2 inflammation.
... Inexhaustible sources of natural chemical constituents, suitable chemical characteristics, and various biological and pharmacological activities have been attributed to phytochemical-based-therapeutic agents (Blowman et al., 2018;Sampath et al., 2018). Cancer therapy has widely employed phytochemicals with potential antitumor activities (Khazir et al., 2014;Murata et al., 2013). Previous research has shown essential oils (EOs) anticancer properties with various mechanisms of action. ...
... EOs refer to secondary metabolites that plants generate to protect themselves against pests and predators and increase appeal to pollinators or promote seed dissemination. These oils can be obtained from numerous parts of plants, for instance, roots and aerial parts: stems, leaves, flowers, fruits, and seeds, according to their species (Mugao et al., 2020). EOs have been known for their anticancer properties with a wide range of mechanisms, such as their role in cancer chemoprevention and the ability to interfere with established tumor cells and interact with the tumor microenvironment (Bayala et al., 2014;Blowman et al., 2018). ...
... Citronellal and geraniol, monoterpene alcohol, and monoterpene aldehyde, respectively, were recognized for their antiproliferative activities . Citronellal demonstrates a potent ability to promote transient calcium signaling and activate human olfactory receptor OR1A2, which results in phosphorylation of p38 MAPK and hinders cell proliferation (Maßberg et al., 2015). Conversely, geraniol is able to restrain AKT signaling and stimulate AMPK signaling, which consequently leads to mTOR inhibition, thus cell apoptosis and autophagy (Kim et al., 2012). ...
... The canonical OR signalling model involves heterotetrameric CNG channels, particularly CNGA2, and also CNGA4 and CNGB1; however, these channels were not detected in most non-nasal tissues 7 . CNGA1, which can form exogenous functional homomeric channels and is activated by cGMP, is the most prominent channel in peripheral cells and tissues 157 and may function as the CNG channel used by ectopic ORs 10, 125 . The native cone photoreceptor channel CNGA3 is expressed and functional in spermatozoa 158 . ...
... OR1A2, the paralogous receptor to OR1A1, is expressed in hepatic cancer cells 125 . The (-)-citronellalactivated olfactory receptor OR1A2 evokes a cAMPdependent cytosolic Ca 2+ increase in the hepatocellular carcinoma Huh7 cell line, in which the olfactory signalling components ACIII, G αolf and the CNG channel subunit CNGA1 are expressed 125 . ...
... OR1A2, the paralogous receptor to OR1A1, is expressed in hepatic cancer cells 125 . The (-)-citronellalactivated olfactory receptor OR1A2 evokes a cAMPdependent cytosolic Ca 2+ increase in the hepatocellular carcinoma Huh7 cell line, in which the olfactory signalling components ACIII, G αolf and the CNG channel subunit CNGA1 are expressed 125 . Moreover, (-)-citronellal mediates the phosphorylation of p38 MAPK and promotes a reduction in cell proliferation 125 . ...
Olfactory and taste receptors are expressed primarily in the nasal olfactory epithelium and gustatory taste bud cells, where they transmit real-time sensory signals to the brain. However, they are also expressed in multiple extra-nasal and extra-oral tissues, being implicated in diverse biological processes including sperm chemotaxis, muscle regeneration, bronchoconstriction and bronchodilatation, inflammation, appetite regulation and energy metabolism. Elucidation of the physiological roles of these ectopic receptors is revealing potential therapeutic and diagnostic applications in conditions including wounds, hair loss, asthma, obesity and cancers. This Review outlines current understanding of the diverse functions of ectopic olfactory and taste receptors and assesses their potential to be therapeutically exploited.
... Ectopic expression of ORs has been reported since the early 1990s [13]. In cancer, OR expression has been identified in non-small-cell lung cancer, gastrointestinal, neuroendocrine, hepatocellular, and prostate carcinomas, among others [32,[77][78][79][80][81][82]. In some cases, the activation of these ORs led to apoptosis, inhibition of cell migration and proliferation, differentiation, and resistance to drugs [18,21,32,77,82,83]. ...
... OR activation can trigger many physiological processes in the cell, even if initiating alternative signaling pathways instead of the canonical one. It has been published that ORs in cancer when activated, can increase the Ca 2+ concentration in the cytosol [92], phosphorylate p38 and Erk1/2 MAPK [21], stimulate the cAMP/PKA pathway and EGFR and AKT signaling cascades, and increase cell proliferation, angiogenesis, cell cycle arrest, cell survival, and apoptosis [71,79,93]. In acute lymphoblastic leukemia, mutations in OR2C3 have been associated with the development of the disease during childhood [94]. ...
Acute myeloid leukemia (AML) is the most common form of acute leukemia in adults, with a 5-year overall survival rate of approximately 30%. Despite recent advances in therapeutic options, relapse remains the leading cause of death and poor survival outcomes. New drugs benefit specific small subgroups of patients with actionable therapeutic targets. Thus, finding new targets with greater applicability should be pursued. Olfactory receptors (ORs) are seven transmembrane G-protein coupled receptors preferentially expressed in sensory neurons with a critical role in recognizing odorant molecules. Recent studies have revealed ectopic expression and putative function of ORs in nonolfactory tissues and pathologies, including AML. Here, we investigated OR expression in 151 AML samples, 6400 samples of 15 other cancer types, and 11,200 samples of 51 types of healthy tissues. First, we identified 19 ORs with a distinct and major expression pattern in AML, which were experimentally validated by RT-PCR in an independent set of 13 AML samples, 13 healthy donors, and 8 leukemia cell lines. We also identified an OR signature with prognostic potential for AML patients. Finally, we found cancer-related genes coexpressed with the ORs in the AML samples. In summary, we conducted an extensive study to identify ORs that can be used as novel biomarkers for the diagnosis of AML and as potential drug targets.
... On the other hand, the olfactory transduction pathway is composed of a large number of genes from the G protein family. In recent years, the expression of these genes has been detected in multiple processes across different tissues [37,38,[40][41][42][43] including some cancer-related functions. ...
... It is structurally similar to the cellular retinol-binding proteins but binds only retinoic acid at specific sites within the nucleus, contributing to vitamin A-directed differentiation in epithelial tissue. a CRABP1 has found that its under-expression in some other cancers such as breast cancer and ovarian adenocarcinoma is related to poor prognosis [37,38] royalsocietypublishing.org/journal/rsos R. Soc. Open Sci. ...
Retinoblastoma (Rb) is a rare intraocular tumour in early childhood, with an approximate incidence of 1 in 18 000 live births. Experimental studies for Rb are complex due to the challenges associated with obtaining a normal retina to contrast with diseased tissue. In this work, we reanalyse a dataset that contains normal retina samples. We identified the individual genes whose expression is different in Rb in contrast with normal tissue, determined the pathways whose global expression pattern is more distant from the global expression observed in normal tissue, and finally, we identified which transcription factors regulate the highest number of differentially expressed genes (DEGs) and proposed as transcriptional master regulators (TMRs). The enrichment of DEGs in the phototransduction and retrograde endocannabinoid signalling pathways could be associated with abnormal behaviour of the processes leading to cellular differentiation and cellular proliferation. On the other hand, the TMRs nuclear receptor subfamily 5 group A member 2 and hepatocyte nuclear factor 4 gamma are involved in hepatocyte differentiation. Therefore, the enrichment of aberrant expression in these transcription factors could suggest an abnormal retina development that could be involved in Rb origin and progression.
... Ectopic expression of ORs has been reported since the early 1990s 12 . In cancer, OR expression has been identified in non-small-cell lung cancer, gastrointestinal neuroendocrine, hepatocellular and prostate carcinomas, among others [49][50][51][52] . In some cases, the activation of these ORs led to apoptosis, inhibition of cell migration and proliferation, differentiation, and resistance to drugs 17,20,49 . ...
... The testis was one of the first tissues reported to have ectopic expression of ORs, and it is a tissue known for showing broad expression of ORs and other genes in general 12 OR activation can trigger many physiological processes in the cell even if initiating alternative signaling pathways instead of the canonical one. It has been published that ORs in cancer, when activated, can increase the Ca 2+ concentration in the cytosol, phosphorylate p38 and Erk1/2 MAPK 20 , stimulate the cAMP/PKA pathway and EGFR and AKT signaling cascades, and increase cell proliferation, angiogenesis, cell cycle arrest, cell survival and apoptosis 51,61,62 . In acute lymphoblastic leukemia, mutations in OR2C3 have been associated with the development of the disease during childhood 63 . ...
Acute myeloid leukemia (AML) is the most common form of acute leukemia in adults. Although new drugs for specific molecular subsets of AML have recently emerged, the 5-year overall survival rate is still approximately 25%. The treatment options for AML have remained stagnant for decades, and novel molecular targets for this disease are needed. Olfactory receptors (ORs) are seven transmembrane G-protein coupled receptors preferentially expressed in sensory neurons, in which they play a critical role in recognizing odorant molecules. Recent studies have revealed ectopic expression and putative function of ORs in nonolfactory tissues and pathologies, including AML. Here, we comprehensively investigated OR expression in 151 AML samples, 51 healthy tissues (approximately 11,200 samples), and 15 other cancer types (6,400 samples). Our analyses identified a group of 19 ORs with a distinct and major expression pattern in AML. The expression of these ORs was experimentally validated in an independent set of AML samples and cell lines. We also identified an OR signature with prognostic value for AML patients. Finally, we identified cancer-related genes that were coexpressed with the ORs in the AML samples. In summary, we conducted a high-throughput computational study to identify ORs that can be used as novel biomarkers for the diagnosis of AML and as potential drug targets. The same approach may be used to investigate OR expression in other types of cancer.
... (E) OR1A2 stimulation reduces proliferation of hepatocarcinoma cells, adapted from [117]. (F) OR10H1 is capable of inhibiting bladder cancer cell proliferation and migration and inducing apoptosis when stimulated by its agonist [118]. (G) Activation of OR2J3 inhibits cell migration and proliferation and induces apoptosis in lung cancer cells [119]. ...
... In a bladder cancer cell line, OR10H1 is capable of triggering cell cycle arrest and apoptosis and inhibiting cell proliferation and migration when stimulated by its agonist Sandranol. The downstream signaling pathway of OR10H1 involves calcium influx and cAMP increase [118] (Figure 6). Activation of OR2J3 by its agonist helional enhances cytosolic Ca 2+ level via a PI3K-mediated pathway, inhibits cell proliferation and migration, and induces apoptosis of A549 cells [119] (Figure 6). ...
Prompted by the ground-breaking discovery of the rodent odorant receptor (OR) gene family within the olfactory epithelium nearly 30 years ago, followed by that of OR genes in cells of the mammalian germ line, and potentiated by the identification of ORs throughout the body, our appreciation for ORs as general chemoreceptors responding to odorant compounds in the regulation of physiological or pathophysiological processes continues to expand. Ectopic ORs are now activated by a diversity of flavor compounds and are involved in diverse physiological phenomena varying from adipogenesis to myogenesis to hepatic lipid accumulation to serotonin secretion. In this review, we outline the key biological functions of the ectopic ORs responding to flavor compounds and the underlying molecular mechanisms. We also discuss research opportunities for utilizing ectopic ORs as therapeutic strategies in the treatment of human disease as well as challenges to be overcome in the future. The recognition of the potent function, signaling pathway, and pharmacology of ectopic ORs in diverse tissues and cell types, coupled with the fact that they belong to G protein-coupled receptors, a highly druggable protein family, unequivocally highlight the potential of ectopic ORs responding to flavor compounds, especially food-derived odorant compounds, as a promising therapeutic strategy for various diseases.
... They have been reported to exert many varied biological activities including anti-inflammatory and anti-microbial activities [16]. Citronellal exhibited toxicity against MCF-7 breast cancer cells [17] and reduced proliferation by inducing apoptosis in Huh7 hepatocellular carcinoma [18], while citronellol induced necroptosis of lung cancer [19]. Both molecules have also been reported to inhibit the action of multidrug resistance P-glycoprotein, which ameliorates the efficacity of drug treatments [20]. ...
... Anti-proliferative effects of C. hystrix were also reported in previous studies on leukemic cell lines [23] and on HeLa cervical cancer cells [21], while the anti-proliferative effect on MDA-MB-231 cells was also significant under treatments of both citronellol and citronellal. A previous study reported that citronellal reduced proliferation in Huh7 hepatocellular carcinoma cells [18], while citronellol inhibited non-small cell lung carcinoma A-549 cells [24]. Further experiments were performed to support the results of pre-existing anti-proliferative effects of both crude hexane extract and the two pure compounds. ...
Triple negative breast cancer is one of the most aggressive breast cancer type with abilities of early metastasis and chemoresistance. The tropical plant Citrus hystrix DC. has been reported to promote many biological activities including anticancer. However, the effect of C. hystrix against triple negative breast cancer has not yet been identified. This study aimed to evaluate the anticancer properties of C. hystrix leaf extract and its bioactive constituents citronellol and citronellal against the triple negative breast cancer MDA-MB-231 cell line. C. hystrix leaves were powdered and sequentially macerated. The in vitro anticancer effects of C. hystrix leaf extracts, and its bioactive constituents (citronellol and citronellal) were evaluated against MDA-MB-231 cell line using cytotoxic MTT assay, cell proliferation, wound scratch migration, colony formation, cell cycle, apoptosis assay, Hoechst staining, RT-qPCR, and Western blot analysis. Results showed that crude hexane extract, citronellol, and citronellal significantly reduced cell proliferation, colony formation, and cell migration by inducing cell cycle arrest, while also inducing apoptosis in MDA-MB-231 cells through inhibition of anti-apoptotic Bcl-2 expression, leading to activation of the caspase-3-dependent pathway. This study is the first report to demonstrate the effect of C. hystrix, citronellol, and citronellal against triple negative breast cancer MDA-MB-231 cells.
... OR1A2 (UniProtID: Q9Y585) is an OR, known to be ectopically expressed in several tissues at transcript level including blood, brain, heart, liver, pancreas among others as indicated by GeneCards (GCID: GC17P003197) (Stelzer et al., 2016). OR1A2 has been heterologously expressed and identified at the protein level in Huh7 cells, a model system for hepatocellular carcinoma, where the activation of OR1A2 by (S)-(À)-citronellal leads to calcium signalling and reduction in cell proliferation (Massberg et al., 2015). Currently, the known odorant space of OR1A2 is comprised primarily of 13 ligands (terpenes, alcohols and aldehydes; Supporting information: Table S1), which are all agonists. ...
... The total 13 experimentally known ligands (Supporting information: Table S1) for OR1A2 reported in the literature (Massberg et al., 2015;Schmiedeberg et al., 2007) were downloaded from PubChem (Kim et al., 2016). We utilized the APF technique, incorporated in the ICM software (MolSoft v.3.8-5, ...
Olfactory receptor (OR) 1A2 is the member of largest superfamily of G protein-coupled receptors (GPCRs). OR1A2 is an ectopically expressed receptor with only 13 known ligands, implicated in reducing hepatocellular carcinoma progression, with enormous therapeutic potential. We have developed a two-stage screening approach to identify novel putative ligands of OR1A2. We first used a pharmacophore model based on atomic property field (APF) to virtually screen a library of 5942 human metabolites. We then carried out structure-based virtual screening (SBVS) for predicting the potential agonists, based on a 3D homology model of OR1A2. This model was developed using a biophysical approach for template selection, based on multiple parameters including hydrophobicity correspondence, applied to the complete set of available GPCR structures to pick the most appropriate template. Finally, the membrane-embedded 3D model was refined by molecular dynamics (MD) simulations in both the apo and holo forms. The refined model in the apo form was selected for SBVS. Four novel small molecules were identified as strong binders to this olfactory receptor on the basis of computed binding energies.
... Kaempferol Anti-apoptotic, pro-wound healing, anti-cancer, cardioprotective, anti-oxidant, pro-apoptotic, anti-allergic, anti-parasitic, antidiabetic, anti-adipogenic, anti-thrombotic, anti-inflammatory, anti-metabolic syndrome, anti-bacterial, immunoregulatory, hepatoprotective, anti-atherosclerosis [28][29][30][31][32][33][34][35] Linalool Anti-parasitic, anti-convulsant, anti-cancer, anti-bacterial, neuroprotective, anti-oxidant, anti-inflammatory, anti-Alzheimer, anxiolytic, hepatoprotective, anti-hyperalgesic, neuroprotective [36][37][38][39][40][41][42][43] Citronellal Anti-fungal, insect repellant, hepatoprotective, anti-nociceptive, anti-inflammatory, anti-bacterial [44][45][46] Caryophyllene Anti-cancer, anti-mutagenic, anti-bacterial, oxygen deprivation protective, neuroprotective, hepatoprotective, anti-convulsant, anti-diabetic, anti-microbial, anti-Alzheimer, pro-longevity, analgesic, nephroprotective [47][48][49][50][51][52][53][54][55][56] Humulene Insecticidal, anti-cancer, anti-inflammatory [51,57,58] Neridiol Anti-parasitic, antioxidant, neuroprotective, pro-wound healing, anti-microbial [59][60][61][62] While it is clear that L. candidum possesses many valuable compounds with considerable therapeutic potential, to the best of our knowledge, no bioinformatical research has been carried out to assess their medicinal potential. In order to close this gap, we analyzed the potential human therapeutic targets (proteins and other biomolecules) of the above-mentioned compounds, using the STITCH database (http://stitch.embl.de/) ...
... Kaempferol Anti-apoptotic, pro-wound healing, anti-cancer, cardioprotective, anti-oxidant, pro-apoptotic, anti-allergic, anti-parasitic, anti-diabetic, anti-adipogenic, anti-thrombotic, anti-inflammatory, anti-metabolic syndrome, anti-bacterial, immunoregulatory, hepatoprotective, anti-atherosclerosis [28][29][30][31][32][33][34][35] Linalool Anti-parasitic, anti-convulsant, anti-cancer, anti-bacterial, neuroprotective, anti-oxidant, anti-inflammatory, anti-Alzheimer, anxiolytic, hepatoprotective, anti-hyperalgesic, neuroprotective [36][37][38][39][40][41][42][43] Citronellal Anti-fungal, insect repellant, hepatoprotective, anti-nociceptive, anti-inflammatory, anti-bacterial [44][45][46] Caryophyllene Anti-cancer, anti-mutagenic, anti-bacterial, oxygen deprivation protective, neuroprotective, hepatoprotective, anti-convulsant, anti-diabetic, anti-microbial, anti-Alzheimer, pro-longevity, analgesic, nephroprotective [47][48][49][50][51][52][53][54][55][56] Humulene Insecticidal, anti-cancer, anti-inflammatory [51,57,58] Neridiol Anti-parasitic, antioxidant, neuroprotective, pro-wound healing, anti-microbial [59][60][61][62] While it is clear that L. candidum possesses many valuable compounds with considerable therapeutic potential, to the best of our knowledge, no bioinformatical research has been carried out to assess their medicinal potential. In order to close this gap, we analyzed the potential human therapeutic targets (proteins and other biomolecules) of the above-mentioned compounds, using the STITCH database (http://stitch.embl.de/) ...
Lilium candidum L., known as Madonna, meadow, or white lily, is a bulbous plant from the Liliaceae family, originating in the Middle East. L. candidum has been abundantly used in folk medicine since ancient times to relieve a variety of ailments, including age-related diseases, burns, ulcers, and coughs. The aim of this article is to investigate the anti-inflammatory and anti-diabetic activities of L. candidum extracts and its active phytochemicals. Some active volatile phytochemicals were identified using gas chromatography–mass spectrometry (GC-MS) analysis. Significant (p < 0.001) anti-diabetic properties of the extracts kaempferol, linalool, citronellal, and humulene were demonstrated by an elevation in glucose uptake by adipocytes. The significant (p < 0.01) effect of the plant extracts kaempferol, citronellal, and humulene on the secretion of pro-inflammatory cytokines interleukin 6 (IL-6) and interleukin 8 (IL-8) was demonstrated using enzyme-linked immunosorbent assay. Altogether, L. candidum and its rich collection of phytochemicals hold promising medicinal potential, and further investigations of its therapeutic prospects are encouraged.
... The UCSC genome browser view of AR binding to OR gene chromatin locations in LNCaP control or TRAF4overexpressing cells is shown in SI Appendix, Fig. S12. ORs are the largest family of G-protein-coupled receptors, which stimulate intracellular cyclic adenosine monophosphate (cAMP) signaling upon activation (42)(43)(44). Using a lower threshold (log 2 TRAF4/ vector > 1) for gene ontology analysis with the same dataset, we found renin secretion and cAMP signaling as the topmost enriched pathways (SI Appendix, Fig. S13). ...
Castration-resistant prostate cancer (CRPC) poses a major clinical challenge with the androgen receptor (AR) remaining to be a critical oncogenic player. Several lines of evidence indicate that AR induces a distinct transcriptional program after androgen deprivation in CRPCs. However, the mechanism triggering AR binding to a distinct set of genomic loci in CRPC and how it promotes CRPC development remain unclear. We demonstrate here that atypical ubiquitination of AR mediated by an E3 ubiquitin ligase TRAF4 plays an important role in this process. TRAF4 is highly expressed in CRPCs and promotes CRPC development. It mediates K27-linked ubiquitination at the C-terminal tail of AR and increases its association with the pioneer factor FOXA1. Consequently, AR binds to a distinct set of genomic loci enriched with FOXA1- and HOXB13-binding motifs to drive different transcriptional programs including an olfactory transduction pathway. Through the surprising upregulation of olfactory receptor gene transcription, TRAF4 increases intracellular cAMP levels and boosts E2F transcription factor activity to promote cell proliferation under androgen deprivation conditions. Altogether, these findings reveal a posttranslational mechanism driving AR-regulated transcriptional reprogramming to provide survival advantages for prostate cancer cells under castration conditions.
... Anti-fungal, insect repellant, hepatoprotective, anti-nociceptive, anti-inflammatory, anti-bacterial [42][43][44] Caryophyllene Anti-cancer, anti-mutagenic, anti-bacterial, oxygen deprivation protective, neuroprotective, hepatoprotective, anti-convulsant, antidiabetic, anti-microbial, anti-Alzheimer, pro-longevity, analgesic, nephroprotective. ...
Nature has always been a supreme source for many therapeutic compounds yielding us with many microorganisms producing beneficial chemicals and medicinal plants. The herbal or medicinal plant is used to heal & treat different human diseases from ancient times. In the current era, people suffering from numerous diseases and taking synthetic drugs, which show several side effects and damage our precious body by life-threatening diseases. The main goal of this review article is to highlight the different phytochemicals & pharmacological activities of Lilium polyphyllum based on various scientific literature surveys. The common name of Lilium polyphyllum is "White Himalaya lily" which belongs to the family Liliaceae.It is marked as a precious plant of the Indian system of medicine. It is mainly found in different states of North and West-India, USA, Italy, Phytochemical studies showed that Lilium polyphyllum is a rich source of different active chemical constituents like alkaloids, furocoumarins, flavonoids, O-isopentenyl, halfordinol, glycoside, etc. Major pharmacological activities and steroid glycerides presented by this plant are anti-inflammatory activity, anti-tumor, anti-depression, anti-bacterial and also used to treat hyperdipsia, haematemesis, intermittent fever,bronchitis, rheumatology& general disability etc. Therefore, it can be concluded that "Lilium polyphyllum" may be considered as a natural source of many pharmacologically active constituents and useful for the development of herbal formulations.
... Human OR1A2 Inhibition of cell proliferation [37] 3T3-L1 Mouse OLFR544 Triglycerides hydrolyzation [38] Adipose tissue ...
... Two acyclic monoterpenoids (citronellol and citronellal that have been iden fied in C. hystrix) have been reported to exert many varied biological ac vi es [70]. Citronellal exhibited toxicity against cancer cells (MCF-7 breast) [71] and reduced prolifera on hepatocellular carcinoma (Huh7) by inducing apoptosis [72]. While citronellol induced necroptosis of lung cancer cell [73]. ...
Herbal medicines have played a critical role in the treatment and prevention of some diseases. Among a diversity of natural medicinal sources, Citrus hystrix DC. is an outstanding plant broadly distributed in tropical regions. Citrus hystrix DC. has many biological activities, and it has been used in traditional medicine for treating various illnesses, particularly cold pain and stomach disorder. This review article focuses to enhance and prepare a comprehensive review on phytochemical and pharmacological studies of Citrus hystrix CD., and aims to lay the foundation for further study on the extraction enhancement of these biomolecules and more useful formulations. Based on published scientific data, these plants may suggest a gigantic biological potential of an abundant source of chemical constituents and a variety of bioactivities contributing to therapeutic values.
... According to our functional analysis using KEGG and GO, these off-targets are involved in several cancer pathways and vasoconstriction and blood circulation, respectively. Although the function of ectopic ORs is mainly unknown, recent studies suggest they influence liver cell metabolism-by modulating the triglyceride metabolism [58]-and are overexpressed in liver tumours [59], where they mediate the reduction of hepatocellular carcinoma progression [60]. Therefore, even though the effect of ectopic ORs in drug-induced liver injury has not been observed yet, we believe their potential mechanism in DILI could be related to alterations in the regeneration of hepatocytes, or an imbalance between the production of lipids and their oxidation or transport, that affect the ratio of monounsaturated fatty acids and saturated fatty acids leading to apoptosis and liver damage. ...
Among adverse drug reactions, drug-induced liver injury presents particular challenges because of its complexity, and the underlying mechanisms are still not completely characterized. Our knowledge of the topic is limited and based on the assumption that a drug acts on one molecular target. We have leveraged drug polypharmacology, i.e., the ability of a drug to bind multiple targets and thus perturb several biological processes, to develop a systems pharmacology platform that integrates all drug–target interactions. Our analysis sheds light on the molecular mechanisms of drugs involved in drug-induced liver injury and provides new hypotheses to study this phenomenon.
... carvone [45]. OR1A2 is expressed in HuH7 cells, and it is sensitive to (-)-citronellal and citronellol [46]. LNCaP cells express OR51E1 and OR51E2 (also named prostate-specific G-protein-coupled receptor [PSGR]), which recognize β-ionone, propionic acid, butyric acid, and nonanoic acid [47,48]. ...
Humans use a family of more than 400 olfactory receptors (ORs) to detect odorants. However, deorphanization of ORs is a critical issue because the functional properties of more than 80% of ORs remain unknown, thus, hampering our understanding of the relationship between receptor function and perception. HEK293 cells are the most commonly used heterologous expression system to determine the function of a given OR; however, they cannot functionally express a majority of ORs probably due to a lack of factor(s) required in cells in which ORs function endogenously. Interestingly, ORs have been known to be expressed in a variety of cells outside the nose and play critical physiological roles. These findings prompted us to test the capacity of cells to functionally express a specific repertoire of ORs. In this study, we selected three cell lines that endogenously express functional ORs. We demonstrated that human prostate carcinoma (LNCaP) cell lines successfully identified novel ligands for ORs that were not recognized when expressed in HEK293 cells. Further experiments suggested that the LNCaP cell line was effective for functional expression of ORs, especially with a high basal activity, which impeded the sensitive detection of ligand-mediated activity of ORs. This report provides an efficient functional assay system for a specific repertoire of ORs that cannot be characterized in current cell systems.
... Based on these findings, Nthy-ori 3-1, FTC 133, and BCPAP cells were selected as suitable in vitro models for further characterization of the functional impact of OR2H2 and OR2W3 in human benign and malignant thyroid cells. Activation of an OR by its specific ligand leads in most cell types to an alteration of the intracellular Ca 2+ level (Maßberg et al., 2015;Manteniotis et al., 2016b;Kalbe et al., 2017). Therefore, we used the Ca 2+ imaging technique to analyze whether OR2H2 and OR2W3 were functionally expressed in the thyroid cell lines. ...
Olfactory receptors (ORs) are almost ubiquitously expressed in the human body. However, information about their functions in these tissues is lacking. To date, no functional characterization of expressed ORs in the human thyroid has been performed. In this study, we detected and compared the expression of OR2H2 and OR2W3 in healthy and malignant cell lines and their corresponding tissues, respectively. We demonstrated that stimulation of ORs by their specific ligand resulted in a transient increase in intracellular calcium and cAMP concentrations. In the case of OR2H2, the downstream signaling cascade analysis revealed that adenylate cyclase (AC) and phosphoinositide phospholipase C (PLC) were involved. Furthermore, OR2H2 and OR2W3 activation affected migration, proliferation, and invasion. These are the first insights that ORs influence physiology-relevant processes in the healthy and malignant thyroid.
... [110] Many studies have reported the presence of odorant receptor transcripts in heart, brain, germ cells, sperms, and mammalian testes [9,11,13,86,112]. Their essential physiological roles include skin wound repair [113], inhibition of proliferation of oncogenic cells in liver, prostate and intestine [8,114,115], and modulation sperm motility [7]. Despite of all the efforts made to unveil the functional specificity of these receptors in the nonolfactory tissues, only few ORs could be aligned with their ligands. ...
Sperm chemotaxis, which guide sperm toward oocyte, is tightly associated with sperm capacitation, motility, and fertility. However, the molecular mechanism of sperm chemotaxis is not known. Re-productive odorant and taste receptors, belong to G-protein-coupled receptors (GPCR) super-family, cause an increase in intracellular Ca2+ concentration which is pre-requisite for sperm capacitation and acrosomal reaction, and result in sperm hyperpolarization and increase motility through ac-tivation of Ca2+-dependent Cl¯ channels. Recently, odorant receptors (ORs) in olfactory transduction pathway were thought to be associated with post-thaw sperm motility, freeze tolerance or freeza-bility and cryo-capacitation-like change during cryopreservation. Investigation of the roles of odorant and taste receptors (TRs) is important for our understanding of the freeze tolerance or freezability mechanism and improve the motility and fertility of post-thaw sperm. Here, we re-viewed the roles, mode of action, impact of odorant and taste receptors on sperm chemotaxis and post-thaw sperm quality.
... Work from our laboratory has focused on the characterization of renal OR Olfr1393 and its role in glucose handling (Shepard et al., 2016(Shepard et al., , 2019 and diabetes (Shepard et al., 2019). ORs have also been shown to function in the regulation of adiposity, blood pressure, and carcinoma proliferation Massberg et al., 2015;Wu et al., 2015). TRs have been implicated in glucose and lipid metabolism (Halford et al., 2001; as well as bronchodilation (Deshpande et al., 2010) and Opns have proposed extraocular functions such as rhythmic clock-gene expression and sperm thermotaxis (Leung and Montell, 2017). ...
Sensory receptors, including olfactory receptors (ORs), taste receptors (TRs), and opsins (Opns) have recently been found in a variety of non-sensory tissues where they have distinct physiological functions. As G protein-coupled receptors (GPCRs), these proteins can serve as important chemosensors by sensing and interpreting chemical cues in the environment. We reasoned that the liver, the largest metabolic organ in the body, is primed to take advantage of some of these sensory receptors in order to sense and regulate blood content and metabolism. In this study, we report the expression of novel hepatic sensory receptors – including 7 ORs, 6 bitter TRs, and 1 Opn – identified through a systematic molecular biology screening approach. We further determined that several of these receptors are expressed within hepatocytes, the parenchymal cells of the liver. Finally, we uncovered several agonists of the previously orphaned hepatic ORs. These compounds fall under two classes: methylpyrazines and monoterpenes. In particular, the latter chemicals are plant and fungal-derived compounds with known hepatic protective effects. Collectively, this study sheds light on the chemosensory functions of the liver and unveils potentially important regulators of hepatic homeostasis.
... Moreover, various functional studies highlighted the therapeutic promise of ligand-mediated OR activation in cancer 19,24 . For instance, in the case of hepatocellular carcinoma, the activation of OR1A2 by citronellal leads to a cAMP-dependent increase in cytosolic Ca 2+ ions, thereby impeding cancer cell proliferation 29 . Similarly, Troenan induced activation of OR51B4 in colorectal cancer cells inhibits their migratory potential and instigates apoptosis 30 . ...
Ectopically expressed olfactory receptors (ORs) have been linked with multiple clinically-relevant physiological processes. Previously used tissue-level expression estimation largely shadowed the potential role of ORs due to their overall low expression levels. Even after the introduction of the single-cell transcriptomics, a comprehensive delineation of expression dynamics of ORs in tumors remained unexplored. Our targeted investigation into single malignant cells revealed a complex landscape of combinatorial OR expression events. We observed differentiation-dependent decline in expressed OR counts per cell as well as their expression intensities in malignant cells. Further, we constructed expression signatures based on a large spectrum of ORs and tracked their enrichment in bulk expression profiles of tumor samples from The Cancer Genome Atlas (TCGA). TCGA tumor samples stratified based on OR-centric signatures exhibited divergent survival probabilities. In summary, our comprehensive analysis positions ORs at the cross-road of tumor cell differentiation status and cancer prognosis.
... gypti, que atualmente é transmissor de doenças como dengue, chikungunya e zika, e contra o mosquito Bemisia tabaci, que é uma praga de plantações de tomate. Além de suas propriedades como repelente, o citronelal vem sendo estudado como antioxidante e antidepressivo (VICTORIA et. al., 2014) e sendo usado em pesquisas para redução do hepatocarcinoma (MAßBERG et. al., 2015). A partir do citronelal pode-se produzir o mentol, que é um insumo muito utilizado nas indústrias de alimentos, cosméticos, higiene e fármacos (CORTÉS et. al., 2011;PLÖßER et. al., 2014). ...
A obtenção de citronelal é muito importante para as indústrias, pois este terpenoé utilizado na produção de inúmeros produtos, que vão desde fármacos a produtos daquímica fina. O presente trabalho objetivou estudar, desenvolver e avaliar sistemasreacionais em catálise heterogênea, em fase vapor e fluxo contínuo, aplicados às reações doβ-citronelol, em condições não oxidativas, utilizando catalisador sólido à base de cobresuportado. As amostras reacionais foram analisadas em um cromatógrafo a gás comdetector espectrômetro de massas (CG/EM), a fim de determinar os produtos formados. Apósas análises, constatou-se a produção de citronelal a partir da desidrogenação catalítica doβ-citronelol.
... [30][31][32] Besides, dysregulation of olfactory receptors was reported to regulate cell proliferation, apoptosis, and migration in several cancers. [33][34][35] A recent study demonstrated that olfactory receptors could be used as biomarkers in human breast cancer tissues. 36 In addition to alterations in intercellular communication and sensory perception, cellular metabolism and cell cycle are also frequently deregulated in cancers. ...
This study was aimed at revealing the dynamic regulation of mRNAs, long noncoding RNAs (lncRNAs), and microRNAs (miRNAs) in hepatocellular carcinoma (HCC) and to identify HCC biomarkers capable of predicting prognosis. Differentially expressed mRNAs (DEmRNAs), lncRNAs, and miRNAs were acquired by comparing expression profiles of HCC with normal samples, using an expression data set from The Cancer Genome Atlas. Altered biological functions and pathways in HCC were analyzed by subjecting DEmRNAs to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis. Gene modules significantly associated with disease status were identified by weighted gene coexpression network analysis. An lncRNA-mRNA and an miRNA-mRNA coexpression network were constructed for genes in disease-related modules, followed by the identification of prognostic biomarkers using Kaplan-Meier survival analysis. Differential expression and association with the prognosis of 4 miRNAs were verified in independent data sets. A total of 1220 differentially expressed genes were identified between HCC and normal samples. Differentially expressed mRNAs were significantly enriched in functions and pathways related to “plasma membrane structure,” “sensory perception,” “metabolism,” and “cell proliferation.” Two disease-associated gene modules were identified. Among genes in lncRNA-mRNA and miRNA-mRNA coexpression networks, 9 DEmRNAs and 7 DEmiRNAs were identified to be potential prognostic biomarkers. MIMAT0000102, MIMAT0003882, and MIMAT0004677 were successfully validated in independent data sets. Our results may advance our understanding of molecular mechanisms underlying HCC. The biomarkers may contribute to diagnosis in future clinical practice.
... The alcohol monoterpenes are known for their anticancer potential. Antiproliferative activities of citronellal [43] and geraniol [44,45] have already been reported. This could also explain the cytotoxicity observed using the P69 cells [46]. ...
Objectives
Natural products commonly used in traditional medicine, such as essential oils (EOs), are attractive sources for the development of molecules with anti-proliferative activities for future treatment of human cancers, e.g., prostate and cervical cancer. In this study, the chemical composition of the EO from Cymbopogon nardus was characterized, as well as its antioxidativeproperties and anti-inflammatory and antiproliferative activities on LNCaP cells derived from prostate cancer.
Methods
The chemical composition of the EO was determined by GC/FID and GC/MS analyses. The antioxidative properties were assessed using DPPH radical scavenging assay and ABTS+• radical cation decolorization assay, and the anti-inflammatory capacity was determined by the inhibition of the lipoxygenase activity. Antiproliferative activity was evaluated by MTT assay.
Results
Collectively, our data show that the major constituents of C. nardus EO are citronellal (33.06 %), geraniol (28.40 %), nerol (10.94 %), elemol (5.25 %) and delta-elemene (4.09 %). C. nardus EO shows modest antioxidant and anti-inflammatory activity compared to the standard galic acid. C. nardus EO exhibits the best antiproliferative activity on the prostate cancer cell line LNCaP with an IC50 of 58.0 ± 7.9 μg/mL, acting through the induction of the cell cycle arrest.
Conclusions
This study has determined that C. nardus EO efficiently triggers cytotoxicity and pens a new field of investigation regarding the putative use of this EO in vivo .
... Previously, ORs were thought to only function in the olfactory epithelium and were ignored in regards to tumorigenesis. Recent studies have since refuted this notion and proven that ORs are linked to several cancers and influence many levels of carcinogenesis, including proliferation, migration, invasion, etc. [34,[36][37][38]. ...
Non-gestational choriocarcinoma (NGC) is a rare subtype of choriocarcinoma differing in origin and phenotypic characteristics compared to gestational choriocarcinoma (GC). This study aimed to analyze the molecular biology of GC and NGC and evaluate genetic anomalies of choriocarcinoma subtypes. DNA was extracted and paired from tumor-normal tissue of one NGC and one GC (control) patient for whole-exome sequencing. To further understand the role of DNAJB9, a p53 regulator mutated in the NGC tumor, on p53 upregulation in choriocarcinoma, CRISPR/Cas9 was used to induce DNAJB9 site-specific mutations in choriocarcinoma cells JEG-3. We hypothesized that DNAJB9 dysfunction would result in p53 overexpression. Sequencing revealed the GC tumor contained > 7 times more somatic mutations than the NGC tumor. Missense (98.86% vs. 94.97%), stop-gain (0.57% vs. 0.93%), and frameshift mutations (0.57% vs. 4.10%) were observed in the GC and NGC samples, respectively (x2 = 24.63, P < 0.00001). The transition substitution rate was 67.54% and 55.71% in the GC and NGC samples, while the transversion substitution rate was 32.46% and 44.29% in the GC and NGC samples, respectively (x2 = 11.56, P < 0.000673). Pathway enrichment analysis revealed ECM-receptor interaction and graft-versus-host disease were most enriched in the GC and NGC tumors, respectively. In vitro investigations showed that DNAJB9 mRNA and protein levels were downregulated in Cas9-DNAJB9-sgRNA transfected cells compared to the control (P < 0.001), while p53 protein levels were upregulated. Our findings display the genetic distinctness of choriocarcinoma subtypes, especially NGC, and further highlight the relationship between p53 and DNAJB9 in choriocarcinoma cells, laying the foundation for further investigations.
... Nerve impulses generated after activation of olfactory receptors by odorant molecules, are transmitted to the olfactory bulb and further to the hippocampus, medial olfactory cortex and other structures in the central nervous system. [4] Studying these possible interactions seems to be interesting in the light of recent discoveries on olfactory function, as well as possible beneficial effects of organic volatiles on the development and progression of Alzheimer's disease. Neurons responsible for receiving and processing stimuli from olfactory receptors are amongst the first to deteriorate in Alzheimer's disease. ...
Terpenes are a widespread group of secondary metabolites that can be found in various family plants such as the Lamiaceae. In view of their numerous valuable biological activities, the industrial production of concrete terpenes and essential oils rich in the substances is intensively studied. Monoterpenes constitute a significant part of the whole group of the aforementioned secondary metabolites. This is due to their numerous biological activities and their ability to permeate the skin. Despite the fact that these substances have gain popularity, they are not comprehensive characterized. The presented review is based on studies of the biological activities of the most important monoterpenes and the essential oils rich in these compounds. The authors focused attention on antioxidant activity, inhibition towards acetyl‐ and butyrylcholinesterase, and α‐amylase and α‐glucosidase, antifungal, hepatoprotective, sedative properties, and their skin permeation enhancement.
... The analysis and functional characterization of ectopically expressed human ORs is becoming increasingly important as many ORs have been identified in several healthy and cancerous tissues, and show tumor-specific regulation (reviewed in Kang & Koo 2012, see also Weng et al. 2005, Cunha et al. 2006, Leja et al.2009, Cui et al. 2013, Giandomenico et al. 2013, Pronin et al. 2014, Sanz et al. 2014, Cao et al. 2015, Maßberg et al. 2015, Flegel et al. 2016, Manteniotis et al. 2016ab, Jovancevic et al. 2017b, Weber et al. 2017. Some ORs have even emerged as specific diagnostic and therapeutic targets for various cancers (Xu et al. 2000, Weng et al. 2005, Leja et al. 2009, Giandomenico et al. 2013, Muranen et al. 2011, Cui et al. 2013, Morita et al. 2016 and in the process of wound healing (Busse et al. 2014). ...
Olfactory receptors (ORs) constitute the largest family of G-protein coupled receptors. They are responsible for the perception of odor (olfaction) and also play important roles in other biological processes, including regulation of cell proliferation. Their increasing diagnostic and therapeutic potential, especially for cancer research, requests the ongoing development of methodologies that would allow their robust functional expression in non-olfactory cells, and dynamic analysis of their signaling pathways. To enable realtime detection of OR activity, we use single cell imaging with genetically encoded fluorescent biosensors, Yellow Cameleon or EPAC, which are routinely used for kinetic measurements of Ca2+ or cAMP signaling downstream of various G-protein coupled receptors. We demonstrate that the co-expression of Lucy-Rho tagged variants of ORs together with an accessory protein, RTP1s, in HEK293TN cells is sufficient to detect the activity of a panel of ORs. Using this methodology, we were able to detect both Ca2+ and cAMP signaling downstream of twelve ORs within 2 minutes from the application of odorant.
... Upon binding to extracellular stimuli-including but not limited to odorant molecules, hormones, and transmitters-they transduce the signal internally and activate various signaling pathways in a cell type-dependent manner. In most cell types outside the OE, activation of ORs leads to an increase of intracellular second messenger cAMP and subsequent calcium flux from outside the cells (54)(55)(56)(57)(58)(59)(60)(61). Functions of ORs in non-OE tissues vary as well. ...
Significance
Up to 15% of couples experience infertility. Implantation must occur in order for the pregnancy hormone hCG to be detected, and thus many pregnancies go unrecognized before being lost due to implantation failure. Decidualization is a complex differentiation process during which the uterine lining grows and dramatically changes form in response to ovarian hormone stimulus, and this process is required for successful implantation. By developing and utilizing a new reporter cell line, the present study systematically uncovers more than 4,000 genetic and chemical modulators of the human decidual response in the hopes of catalyzing new treatments for female infertility, subfertility, and recurrent pregnancy loss.
... To date mostly synthetic odorants have been identified to activate ectopically expressed ORs, for instance, in wound healing processes 39 or by influencing gut motility through OR activation and the release of serotonin in human gastrointestinal enterochromaffin cells 40 . In pathologic processes synthetic odorant molecules were shown to influence different stages of cancer development 41,42 . More recent findings suggest that ORs might be targetable not only by classical odorant molecules but even by therapeutic compounds. ...
The mammalian olfactory system uses hundreds of specialized G-protein-coupled olfactory receptors (ORs) to discriminate a nearly unlimited number of odorants. Cognate agonists of most ORs have not yet been identified and potential non-olfactory processes mediated by ORs are unknown. Here, we used molecular modeling, fingerprint interaction analysis and molecular dynamics simulations to show that the binding pocket of the prototypical olfactory receptor Olfr73 is smaller, but more flexible, than binding pockets of typical non-olfactory G-protein-coupled receptors. We extended our modeling to virtual screening of a library of 1.6 million compounds against Olfr73. Our screen predicted 25 Olfr73 agonists beyond traditional odorants, of which 17 compounds, some with therapeutic potential, were validated in cell-based assays. Our modeling suggests a molecular basis for reduced interaction contacts between an odorant and its OR and thus the typical low potency of OR-activating compounds. These results provide a proof-of-principle for identifying novel therapeutic OR agonists.
... The dissociation constants (K d ) of hOR1A2 to geraniol and citronellol were calculated as 3.24 × 10 −6 M and 1.45 × 10 −5 M, respectively. These constant values are quite similar to those in other studies using mammalian cell-based systems 26,27 . The results imply that functional hOR1A2 was successfully produced in the HEK-293 cells, while maintaining its functionality. ...
We report a strategy for the human-like smelling of a rose scent utilizing olfactory receptor nanodisc (ND)-based bioelectronic nose devices. In this strategy, a floating electrode (FE)-based carbon nanotube (CNT) field effect transistor (FET) was functionalized with human olfactory receptor 1A2 (hOR1A2)-embedded NDs (hOR1A2NDs). The hOR1A2NDs responded to rose scent molecules specifically, which were monitored electrically using the underlying CNT-FET. This strategy allowed us to quantitatively assess the contents of geraniol and citronellol, the main components of a rose scent, as low as 1 fM and 10 fM, respectively. In addition, it enabled us to selectively discriminate a specific rose odorant from other odorants. Significantly, we also demonstrated that the responses of hOR1A2NDs to a rose scent could be strongly enhanced by enhancer materials like a human nose. Furthermore, the method provided a means to quantitatively evaluate rose scent components in real samples such as rose oil. Since our method allows one to quantitatively evaluate general rose scent ingredients just like a human nose, it could be a powerful strategy for versatile basic research and various applications such as fragrance development.
... Limited data are available for the functional roles of ectopic olfactory receptors, but the overall data suggest that they can be involved in modulation and regulation of important cellular processes like cell survival/apoptosis induction, cell-cell recognition, proliferation and migration [22,28]. For cancer cells, these receptors seem to influence migration and development of metastases from solid tumors [31][32][33][34]. Our present study is one of the first to describe the broad olfactory receptor expression by primary human AML cells, and to the best of our knowledge, it is the first to suggest an association between chemosensitivity/survival in a hematological malignancy. ...
Clonal heterogeneity detected by karyotyping is a biomarker associated with adverse prognosis in acute myeloid leukemia (AML). Constitutive activation of the phosphatidylinositol-3-kinase-Akt-mechanistic target of rapamycin (PI3K-Akt-mTOR) pathway is present in AML cells, and this pathway integrates signaling from several upstream receptors/mediators. We suggest that this pathway reflects biologically important clonal heterogeneity. We investigated constitutive PI3K-Akt-mTOR pathway activation in primary human AML cells derived from 114 patients, together with 18 pathway mediators. The cohort included patients with normal karyotype or single karyotype abnormalities and with an expected heterogeneity of molecular genetic abnormalities. Clonal heterogeneity reflected as pathway mediator heterogeneity was detected for 49 patients. Global gene expression profiles of AML cell populations with and without clonal heterogeneity differed with regard to expression of ectopic olfactory receptors (a subset of G-protein coupled receptors) and proteins involved in G-protein coupled receptor signaling. Finally, the presence of clonal heterogeneity was associated with adverse prognosis for patients receiving intensive antileukemic treatment. The clonal heterogeneity as reflected in the activation status of selected mediators in the PI3K-Akt-mTOR pathway was associated with a different gene expression profile and had an independent prognostic impact. Biological heterogeneity reflected in the intracellular signaling status should be further investigated as a prognostic biomarker in human AML.
Background
Previous studies have demonstrated that PANoptosis is strongly correlated with cancer immunity and progression. This study aimed to develop a PANoptosis-related signature (PANRS) to explore its potential value in predicting the prognosis and immunotherapy response of hepatocellular carcinoma (HCC).
Methods
Based on the expression of PANoptosis-related genes, three molecular subtypes were identified. To construct a signature, the differentially expressed genes between different molecular subtypes were subjected to multivariate least absolute shrinkage and selection operator Cox regression analyses. The risk scores of patients in the training set were calculated using the signature. The patients were classified into high-risk and low-risk groups based on the median risk scores. The predictive performance of the signature was evaluated using Kaplan-Meier plotter, receiving operating characteristic curves, nomogram, and calibration curve. The results were validated using external datasets. Additionally, the correlation of the signature with the immune landscape and drug sensitivity was examined. Furthermore, the effect of LPCAT1 knockdown on HCC cell behavior was verified using in vitro experiments.
Results
This study developed a PANRS. The risk score obtained by using the PANRS was an independent risk factor for the prognosis of patients with HCC and exhibited good prognostic predictive performance. The nomogram constructed based on the risk score and clinical information can accurately predicted the survival probability of patients with HCC. Patients with HCC in the high-risk groups have high immune scores and tend to generate an immunosuppressive microenvironment. They also exhibited a favorable response to immunotherapy, as evidenced by high tumor mutational burden, high immune checkpoint gene expression, high human leukocyte antigen gene expression, low tumor immune dysfunction and low exclusion scores. Additionally, the PANRS enabled the identification of 15 chemotherapeutic agents, including sorafenib, for patients with HCC with different risk levels, guiding clinical treatment. The signature gene LPCAT1 was upregulated in HCC cell lines. LPCAT1 knockdown markedly decreased HCC cell proliferation and migration.
Conclusion
PANRS can accurately predict the prognosis and immunotherapy response of patients with HCC and consequently guide individualized treatment.
Kaposi sarcoma (KS) is an HHV8-associated vascular proliferation that most often involves the skin. Rarely, KS shows marked nuclear atypia or pleomorphism; such examples are known as "anaplastic" KS. This poorly characterized variant often pursues an aggressive course; little is known of its genetic landscape. This study evaluated the clinicopathologic and genomic features of anaplastic KS. We identified 9 anaplastic KS cases from 7 patients and 8 conventional KS cases, including a matched conventional KS and primary-metastasis anaplastic KS pair from a single patient (anaplastic KS diagnosed 9 years after conventional KS). All patients with anaplastic KS were male, aged 51-82 years, who had locally aggressive tumors predominantly affecting the soft tissue and bone of the lower extremities (5/7). Four patients were known to be HIV-positive (all on antiretrovirals), 2 were HIV-negative, and one was of unknown HIV status. The tumors showed angiosarcoma-like or pleomorphic spindle cell sarcoma morphology. Plasma cell-rich chronic inflammation and hemosiderin deposition were commonly present. Single nucleotide polymorphism (SNP) based chromosomal microarray analysis showed the anaplastic KS cohort to demonstrate highly recurrent whole chromosome (chr) gains of chr 7, 11, 19, and 21, which primarily affected olfactory and G-protein coupled receptor (GPCR) signaling, and losses of chr6_q and chrY. Compared to conventional KS, anaplastic KS cases showed significantly more total copy number alterations (CNAs) and more frequent gains of chr7 and chr11_q13.1 (MARK2, RELA, and ESRRA; including high copy number gain in 1 case). Pathway analysis demonstrated these gains preferentially affected genes that facilitate cyclin-dependent cell signaling. Further, anaplastic KS cases were phylogenetically distinct from conventional KS cases, including the patient-matched primary-metastasis anaplastic KS pair and conventional KS. Our study is the first to demonstrate that a more complex genome and distinct CNAs distinguish anaplastic KS from conventional KS. Gains of chr7 and chr11_q13.1 appear central to biological transformation.
Ziel dieser experimentellen Arbeit war das Entdecken eines
neuen Duftstoffes mit wachstumshemmender Wirkung auf Krebszellen und die Untersuchung des Einflusses der Epethelial-mesenchymalen Transition auf die Wirkung dieses Duftstoffes und auf den olfaktorischen Signalweg in Mammakarzinomzelllinien.
Hierfür wurden zunächst verschiedene Duftstoffe an Mammakarzinomzelllinien getestet und deren Wirkung unter anderem mittels MTT-Tests, RNA Extraktion, reverser Transkription und qPCR auf molekularem Level analysiert. Daraufhin wurde in einer zweiten Versuchsreihe versucht, in zwei Zelllinien die EMT zu induzieren. Mittels Western Blots, Immunhistochemie und qPCR wurden der Erfolg der EMT-Induktion und die Auswirkungen der Induktion auf den olfaktorischen Signalweg und die Duftstoffwirkung eruiert.
Durch diese Methoden konnte eine bisher nicht bekannte Wirkung des Duftstoffes Sandranol auf Brustkrebszellen aufgedeckt werden. Sandranol führte in allen untersuchten Zelllinien zu einem starken Abfall von Proliferationsmarkern und einem Anstieg proapoptotischer Moleküle. Es zeigte sich zudem eine weitreichende Reduktion viabler Zellen. In einem zweiten Versuchsansatz konnte, durch Induktion der EMT in mindestens einer der zwei Zelllinien, eine Änderung in dem Expressionsmuster einiger olfaktorischer Rezeptoren nachgewiesen werden. Auch konnte festgestellt werden, dass EMT keinen messbaren attenuierenden Einfluss auf die Wirkung des Duftstoffes Sandranol hatte. Diese Ergebnisse deuten auf ein mögliches therapeutisches Potenzial des Duftstoffes Sandranol hin.
Monoterpenoids are C10 isoprenoid natural products with diverse functions as volatile and non-volatile secondary metabolites. Their biosynthesis from acyclic diphosphate precursors is often accompanied by one or more ring closures, which stabilize the linear, carbocationic intermediates generated during typical terpene synthase reaction sequences. The subset that remains uncyclized following the elimination of the diphosphate group correspondingly retains higher reactivity than their cyclized counterparts, a property that may explain the additional transformations that geraniol and other acyclics undergo to yield monoterpene aldehydes, acids, esters, glycosides, and iridoids, many of which possess allelochemical activity as pollinator attractants, feeding deterrents, or insect repellents. Essential oils of lemon grass (or citronella) (Cymbopogon), rose-scented geraniums (Pelargonium), and lemon-scented gums (Corymbia) are rich sources of the acyclic monoterpene alcohols we collectively refer to in this review as ‘citronelloids’. Their formation from geranyl diphosphate may be brought about by the tps-g or tps-b subclade of terpene synthases or, alternatively, by a subclade of Nudix hydrolases which act preferentially on prenyl diphosphate substrates, yielding monoterpene alcohols in a two step process that involves a monophosphate intermediate. In some members of the Lamiid and Campanulid clades, further oxidation of geraniol and a non-classical, reductive cyclization leads to the iridoids, a group of mostly non-volatile, bicyclic monoterpenes with potent anti-herbivory and anti-inflammatory properties. Here we review the recent literature on acyclic monoterpene biosynthesis, their natural distribution across the plant kingdom, and their emerging roles in medicine as biologically active natural products.
Background
Phytomedicines are proven to treat various chronic diseases as these compounds are cost-effective with few or no side effects. Elucidating the ameliorative effect of phytomedicine on cerebral ischemia may be a potent alternative therapy. Citronellol, a monoterpene alcohol, is one such phyto compound present in the essential oils of Cymbopogon nardus and Pelargonium geraniums and has immense pharmacological properties such as antihyperalgesic, anticonvulsant and antinociceptive.
Objective
In the present work, the anti-ischemic effect of citronellol in both cellular and animal models of stroke was analyzed.
Methods
Citronellol-pretreated SH-SY5Y cells were subjected to oxygen-glucose deprivation and reperfusion. The cells were assessed for cell viability and LDH quantification. Inflammatory cytokines were estimated in the cell lysate of citronellol pretreated OGD-R induced cells. Healthy young SD rats were pretreated with citronellol and induced with MCAO-R. The control group was comprised of sham-operated rats treated with saline. Group II was comprised of MCAO/R-induced untreated rats. Groups III and IV rats were previously treated with 10 mg/kg and 20 mg/kg citronellol, respectively, for 7 consecutive days and induced with MCAO/R. Brain edema was analyzed by quantifying the water content and the percentage of infarct was assessed using the TTC staining technique. Acetylcholinesterase activity and neurological scoring were performed to assess the neuroprotective activity of citronellol. Lipid peroxidation and antioxidant levels were quantified to evaluate the antioxidant activity of citronellol. The anti-inflammatory activity of citronellol was assessed by quantifying proinflammatory cytokines using commercially available ELISA kits.
Results
Citronellol treatment significantly ameliorated neuronal damage in both cellular and animal stroke models. Prior treatment of citronellol significantly decreased the inflammatory cytokines and increased the antioxidants. Citronellol treatment effectively protected the rats from MCAO/R-induced brain edema.
Conclusion
Our results confirm that citronellol is an effective anti-ischemic drug with antioxidant and anti-inflammatory properties.
Background: The Olfactory receptor (OR)-odorant interactions are perplexed. ORs can bind to structurally diverse odorants associated with one or more odor percepts. Various attempts have been made to understand the intricacies of OR-odorant interaction.
Objective: In this study, experimentally documented OR-odorant interactions are investigated comprehensively to; a) suggest potential odor percepts for ORs based on the OR-OR network; b) determine how odorants interacting with specific ORs differ in terms of inherent pharmacophoric features and molecular properties, c) identify molecular interactions that explained OR-odorant interactions of selective ORs; and d) predict the probable role of ORs other than olfaction.
Methods and Results: Human olfactory receptor network (hORnet) is developed to study possible odor percepts for ORs. We identified six molecular properties which showed variation and significant patterns to differentiate odorants binding with five ORs. The pharmacophore analysis revealed that odorants subset of five ORs follow similar pharmacophore hypothesis, (one hydrogen acceptor and two hydrophobic regions) but differ in terms of distance and orientation of pharmacophoric features. To ascertain the binding site residues and key interactions between the selected ORs and their interacting odorants, 3D-structure modelling, docking and molecular dynamics studies were carried out. Lastly, the potential role of ORs beyond olfaction is explored.
Conclusions: A human OR-OR network was developed to suggest possible odor percepts for ORs using empirically proven OR-odorant interactions. We sought to find out significant characteristics, molecular properties, and molecular interactions that could explain OR-odorant interactions and add to the understanding of the complex issue of odor perception.
Odorant receptors (ORs), the largest subfamily of G proteincoupled receptors, detect odorants in the nose. In addition, ORs were recently shown to be expressed in many nonolfactory tissues and cells, indicating that these receptors have physiological and pathophysiological roles beyond olfaction. Many ORs are expressed by tumor cells and tissues, suggesting that they may be associated with cancer progression or may be cancer biomarkers. This review describes OR expression in various types of cancer and the association of these receptors with various types of signaling mechanisms. In addition, the clinical relevance and significance of the levels of OR expression were evaluated. Namely, levels of OR expression in cancer were analyzed based on RNA-sequencing data reported in the Cancer Genome Atlas; OR expression patterns were visualized using t-distributed stochastic neighbor embedding (t-SNE); and the associations between patient survival and levels of OR expression were analyzed. These analyses of the relationships between patient survival and expression patterns obtained from an open mRNA database in cancer patients indicate that ORs may be cancer biomarkers and therapeutic targets.
In forensic science, the emission of odours from objects or biological matrices is exploited for different purposes. For example, the monitoring of odours via biological or analytical detectors is used in thanatochemistry, the chemistry of death. The analysis of decomposition odour can be explored to support the localization of a missing body, a scenario encountered in urban search and rescue operations. A better understanding of the formation and evolution of decomposition odour is also of high interest to human remains detection canine handlers to improve training practices and chose appropriate training aids. Next to thanatochemistry, many other types of evidence evaluation benefit from the characterization of the volatile profile including the analysis of fire debris, chemical threat agents, explosives, and drugs.
From a chemical point of view, an odour represents a complex mixture of gaseous molecules and its characterization demands for a powerful analytical technique. Especailly, in non-targeted analysis, the separation power provided by one-dimensional (1D) gas chromatography (GC) can be surpassed. Thus, a better insight is usually achieved using a multidimensional technique, such as comprehensive two-dimensional gas chromatography (GC×GC). This chapter focuses on scientific articles published between 2015 and 2020 reporting on the use of GC×GC for odour characterization in the context of forensic science. The main points are decomposition odour, volatolomic applications for profiling of human scent and illegal trade goods such as wildlife parts. Furthermore, the investigation of volatile traces of drugs and ignitable liquids in the context of arson investigations is addressed in detail. For each section, the length is proportional to the number of publications from the literature review.
Olfactory receptors (ORs), responsible for the sense of smell, play an essential role in various physiological processes outside the nasal epithelium, including cancer. In breast cancer, however, the expression and function of ORs remain understudied. We examined the significance of OR transcript abundance in primary and metastatic breast cancer to the brain, bone, and lung. While 20 OR transcripts were differentially expressed in distant metastases, OR5B21 displayed an increased transcript abundance in all three metastatic sites compared to the primary tumor. Knockdown of OR5B21 significantly decreased the invasion and migration of breast cancer cells as well as metastasis to different organs especially the brain, while increasing of OR5B21 transcript abundance had the opposite effect. Mechanistically, OR5B21 expression was associated with epithelial to mesenchymal transition through the STAT3/NFκB/CEBPβ signaling axis. We propose OR5B21 (and potentially other ORs) as a novel oncogene contributing to breast cancer metastasis and a potential target for adjuvant therapy.
Olfactory receptors (ORs) constitute the largest superfamily of G protein-coupled receptors (GPCRs). ORs are involved in sensing odorants as well as in other ectopic roles in non-nasal tissues. Matching of an enormous number of the olfactory stimulation repertoire to its counterpart OR through machine learning (ML) will enable understanding of olfactory system, receptor characterization, and exploitation of their therapeutic potential. In the current study, we have selected two broadly tuned ectopic human OR proteins, OR1A1 and OR2W1, for expanding their known chemical space by using molecular descriptors. We present a scheme for selecting the optimal features required to train an ML-based model, based on which we selected the random forest (RF) as the best performer. High activity agonist prediction involved screening five databases comprising ~23 M compounds, using the trained RF classifier. To evaluate the effectiveness of the machine learning based virtual screening and check receptor binding site compatibility, we used docking of the top target ligands to carefully developed receptor model structures. Finally, experimental validation of selected compounds with significant docking scores through in vitro assays revealed two high activity novel agonists for OR1A1 and one for OR2W1.
Citronellal, an acyclic monoterpene with an aldehyde group, is present in many plants, including species of Eucalyptus, Corymbia, Cymbopogon, Coriandrum. It is also known as rhodinol and possesses strong insect repellant and antifungal properties. In this study, we investigated the antiproliferative action of citronellal on hypopharyngeal carcinoma (FaDu) and normal (HEK-293) cell lines. Citronellal suppresses the activity of ornithine decarboxylase (ODC: 77.12±10.73 µM) and inhibits the proliferation of FaDu cells with an IC50 of 71.81±3.37 µM. The qRT-expression analysis depicts citronellal down-regulate the expression of ODC, and a robust binding interaction of citronellal with ODC was observed in molecular docking studies. Further, it also arrests the G2/M phase of FaDu cells, followed by an increase in the number of sub-diploid cells but was non-toxic to normal cell line. The toxicity prediction studies revealed citronellal follows the Lipinski rule of 5 and the Ghose rule. These observations provide experimental evidence for citronellal to be used as a new prototype for designing ODC inhibitors.
Background
Triple-negative breast cancer (TNBC) requires targeted therapies to better manage and prevent metastatic mammary gland tumors. Due to the resistance problem associated with the approved drugs, researchers are now focusing on phytochemicals for the treatment of TNBC as they possess a pleiotropic mode of action and fewer side effects.
Objective
To investigate the antiproliferative effect of citronellal in triple negative breast cancer cells.
Method
Anticancer potential of citronellal was explored by employing SRB, MTT and NRU antiproliferative assay. Further, the effect of citronellal was observed on molecular targets (Tubulin, COX-2 and LOX-5) utilizing in vitro and in silico methods. Furthermore, the efficacy of citronellal was examined on Ehrlich Ascites Carcinoma. In addition, the safety profiling of it was observed at 300 and 1000 mg/kg of body weight in mice.
Results
Citronellal suppresses the growth of MDA-MB-231 cells by more than 50% in NRU assay and ~41% and 32% in SRB and MTT assay, respectively. Further, citronellal's effect was observed on molecular targets wherein it suppressed LOX-5 activity (IC50 40.63±2.27 µM) and prevented polymerization of microtubule (IC50 63.62 µM). The result was more prominent against LOX-5 as supported by molecular docking interaction studies, but a non-significant effect was observed at the transcriptional level. The efficacy of citronellal was also determined in Ehrlich Ascites Carcinoma (EAC) model, wherein it inhibited the growth of tumor cells (45.97%) at 75 mg/kg of body weight. It was non-toxic upto 1000 mg/kg of body weight in mice and did not cause significant lysis of erythrocytes.
Conclusion
These observations could provide experimental support for citronellal to be used as a chemopreventive agent for breast cancer.
Ectopic olfactory receptors (EORs) are expressed in non-nasal tissues of human body. They belong to the G-protein coupled receptor (GPCR) superfamily. EORs may not be capable of differentiating odorants as nasal olfactory receptors (ORs), but still can be triggered by odorants and are involved in different biological processes such as anti-inflammation, energy metabolism, apoptosis etc. Consumption of strong flavored foods like celery, oranges, onions, and spices, is a good aid to attenuate inflammation and boost our immune system. During the digestion of these foods in human digestive system and the metabolization by gut microbiota, the odorants closely interacting with EORs, may play important roles in various bio-functions like serotonin release, appetite regulation etc., and ultimately impact health and diseases. Thus, EORs could be a potential target linking the ligands from food and their bioactivities. There have been related studies in different research fields of medicine and physiology, but still no systematic food oriented review. Our review portrays that EORs could be a potential target for functional food development. In this review, we summarized the EORs found in human tissues, their impacts on health and disease, ligands interacting with EORs exerting specific biological effects, and the mechanisms involved.
Olfactory receptors are primarily known to be expressed in the olfactory epithelium of the nasal cavity and therefore assist in odor perception. With the advent of high-throughput omics technologies such as tissue microarray or RNA sequencing, a large number of olfactory receptors have been reported to be expressed in the nonolfactory tissues. Although these technologies uncovered the expression of these olfactory receptors in the nonchemosensory tissues, unfortunately, they failed to reveal the information about their cell type of origin. Accurate characterization of the cell types should be the first step towards devising cell type-specific assays for their functional evaluation. Single-cell RNA-sequencing technology resolved some of these apparent limitations and opened new means to interrogate the expression of these extranasal olfactory receptors at the single-cell resolution. Moreover, the availability of large-scale, multi-organ/species single-cell expression atlases offer ample resources for the systematic reannotation of these receptors in a cell type-specific manner. In this Viewpoint article, we discuss some of the technical limitations that impede the in-depth understanding of these extranasal olfactory receptors, with a special focus on odorant receptors. Moreover, we also propose a list of single cell-based omics technologies that could further promulgate the opportunity to decipher the regulatory network that drives the odorant receptors expression at atypical locations.
Odor perception in humans is initiated by activation of odorant receptors (ORs) in the nose. However, the ORs linked to specific olfactory percepts are unknown, unlike in vision or taste where receptors are linked to perception of different colors and tastes. The large family of ORs (∼400) and multiple receptors activated by an odorant presents serious challenges. Here, we first use machine learning to screen ∼0.5 million compounds for new ligands and identify enriched structural motifs for ligands of 34 human ORs. We next demonstrate that the activity of ORs successfully predict 146 different perceptual qualities of chemicals. While chemical features have been used to model odor percepts, we show that biologically relevant OR-activity is often superior. Interestingly, each odor percept could be predicted with very few ORs, implying they contribute more to each olfactory percept. A similar model is observed in Drosophila where comprehensive OR-neuron data is available.
Monoterpene is one of the important sources of varietal aroma, which provides a strong floral and fruity aroma in wines. Methyl jasmonate (MeJA) affects plant secondary metabolism. However, the regulatory mechanisms of monoterpene biosynthesis after MeJA application on grapes are not illuminated. In the present study, 10 mM MeJA was used as treatments in Italian Riesling grape at the preveraison stage in different ways, including grape cluster soaking, foliar spraying, and whole vine spraying, designated as T1, T2, and T3, respectively, while a blank group was used as the control (CK). HS-SPME/GC-MS and transcriptome sequencing analysis were performed to investigate the effect of exogenous MeJA on monoterpene synthesis in grape berry skin. The results of GC-MS showed that the application of MeJA induced the accumulation of volatile monoterpenes in grape berry skin, especially linalool, α-terpineol, and oxides. In addition, transcriptome analysis showed that differentially expressed genes were increased from T2 to T3 to T1 compared with CK, and significantly enriched in JA and monoterpene synthesis pathways. T1 application significantly upregulated the mRNA expression levels of LOX2S, AOS, OPR, and JMT involved in the JA biosynthesis pathway, as well as DXS, HMGCR, TPS14, and α-terpineol synthesis genes involved in the monoterpene synthesis pathway compared with T2, T3, and CK. Thus, grape cluster soaking treatment with MeJA could greatly activate volatile monoterpene synthesis. The results will deeply increase our understanding of the monoterpene biosynthesis of grape berry skin in response to MeJA.
The composition of cerebrospinal and brain interstitial fluids is ensured by barriers between the blood and the brain parenchyma (the blood-brain barrier) and between the blood and the cerebrospinal fluid (the blood-cerebrospinal fluid barrier). Barrier function results from the combination of tight junctions between cells that impair solute flux via the paracellular pathway, cell membrane transporters that enable selective transcellular solute passage, and intracellular metabolizing enzymes that transform molecules in transit. Collectively, they comprise a chemical surveillance system, essential to protect the brain from toxicants, microorganisms, and other harmful compounds. Conversely, this chemical surveillance system compromises the brain delivery of many pharmacologic agents against brain cancer and brain metastasis, neurodegenerative diseases, and brain infections. Despite their importance, the mechanisms underlying the regulation of the components of this chemical surveillance system in response to alterations in the composition of blood and brain fluids are still poorly understood. We propose that odorant receptors, vomeronasal receptors and taste receptors, recently identified at brain barriers might be upstream components of this surveillance system. These chemosensory receptors are strategically placed to monitor the composition of blood, cerebrospinal and brain interstitial fluids. Upon ligand-binding, they may deploy the action of transporters and detoxifying enzymes or other unprecedented functions in brain barrier cells, to cope with alterations in the composition of blood and brain cerebrospinal and interstitial fluids, working as guardians of the central nervous system.
This article reports an innovative type of drug-loaded microspheres prepared by precipitation polymerization. The microspheres consist of optically active helical substituted polyacetylene main chains and Schiff base side groups, in which the former provides helical chirality while the latter one is used for chiral citronellal loading. SEM images showed that microspheres with average size about 1 µm were synthesized. Circular dichroism (CD) and UV-vis absorption spectra demonstrated that the polymer chains existed in predominantly one-handed helical structures which contributed largely to the optical activity of the microspheres. The helical structure of polymer and the Schiff base endowed the microspheres with pH- and time-dependent properties and enantio-differentiating resolution capacity towards citronellal. The novel optically active microspheres have potential applications in the fields of chiral drug separation and release, biomedicine, etc.
In the last decades, the use of in vitro systems in liver research has grown exponentially. Important reasons promoting this work are the high throughput and ease of genetic manipulations afforded by these experiments relative to in vivo experiments. Thousands of investigations of hepatocellular carcinoma have been performed employing the human hepatoma Huh-7 cell line. The extensive body of knowledge produced attests to the importance and value of this in vitro cell system to study the characteristics of hepatomas and the potential of natural and synthetic compounds to prevent and eliminate this liver cancer. The necessarily brief summary provided here attempts to summarise some of the most recent achievements and limitations of investigations with Huh-7 cells and derivatives.
Olfactory receptors (ORs) are expressed in the olfactory epithelium, where they detect odorants, but also in other tissues with additional functions. Some ORs are even overexpressed in tumor cells. In this study, we identified ORs expressed in enterochromaffin tumor cells by RT-PCR, showing that single cells can co-express several ORs. Some of the receptors identified were already reported in other tumors, but they are orphan (without known ligand), as it is the case for most of the hundreds of human ORs. Thus, genes coding for human ORs with known ligands were transfected into these cells, expressing functional heterologous ORs. The in vitro stimulation of these cells by the corresponding OR odorant agonists promoted cell invasion of collagen gels. Using LNCaP prostate cancer cells, the stimulation of the PSGR (Prostate Specific G protein-coupled Receptor), an endogenously overexpressed OR, by β-ionone, its odorant agonist, resulted in the same phenotypic change. We also showed the involvement of a PI3 kinase γ dependent signaling pathway in this promotion of tumor cell invasiveness triggered by OR stimulation. Finally, after subcutaneous inoculation of LNCaP cells into NSG immunodeficient mice, the in vivo stimulation of these cells by the PSGR agonist β-ionone significantly enhanced metastasis emergence and spreading.
Olfactory receptors (ORs) provide the molecular basis for the detection of volatile odorant molecules by olfactory sensory neurons. The OR supergene family encodes G-protein coupled proteins that belong to the seven-transmembrane-domain receptor family. It was initially postulated that ORs are exclusively expressed in the olfactory epithelium. However, recent studies have demonstrated ectopic expression of some ORs in a variety of other tissues. In the present study, we conducted a comprehensive expression analysis of ORs using an extended panel of human tissues. This analysis made use of recent dramatic technical developments of the so-called Next Generation Sequencing (NGS) technique, which encouraged us to use open access data for the first comprehensive RNA-Seq expression analysis of ectopically expressed ORs in multiple human tissues. We analyzed mRNA-Seq data obtained by Illumina sequencing of 16 human tissues available from Illumina Body Map project 2.0 and from an additional study of OR expression in testis. At least some ORs were expressed in all the tissues analyzed. In several tissues, we could detect broadly expressed ORs such as OR2W3 and OR51E1. We also identified ORs that showed exclusive expression in one investigated tissue, such as OR4N4 in testis. For some ORs, the coding exon was found to be part of a transcript of upstream genes. In total, 111 of 400 OR genes were expressed with an FPKM (fragments per kilobase of exon per million fragments mapped) higher than 0.1 in at least one tissue. For several ORs, mRNA expression was verified by RT-PCR. Our results support the idea that ORs are broadly expressed in a variety of tissues and provide the basis for further functional studies.
Olfactory receptors (ORs) detect volatile chemicals that lead to the initial perception of smell in the brain. The olfactory receptor (OR) is the first protein that recognizes odorants in the olfactory signal pathway and it is present in over 1,000 genes in mice. It is also the largest member of the G protein-coupled receptors (GPCRs). Most ORs are extensively expressed in the nasal olfactory epithelium where they perform the appropriate physiological functions that fit their location. However, recent whole-genome sequencing shows that ORs have been found outside of the olfactory system, suggesting that ORs may play an important role in the ectopic expression of non-chemosensory tissues. The ectopic expressions of ORs and their physiological functions have attracted more attention recently since MOR23 and testicular hOR17-4 have been found to be involved in skeletal muscle development, regeneration, and human sperm chemotaxis, respectively. When identifying additional expression profiles and functions of ORs in non-olfactory tissues, there are limitations posed by the small number of antibodies available for similar OR genes. This review presents the results of a research series that identifies ectopic expressions and functions of ORs in non-chemosensory tissues to provide insight into future research directions. [BMB Reports 2012; 45(11): 612-622].
For the past 25 years NIH Image and ImageJ software have been pioneers as open tools for the
analysis of scientific images. We discuss the origins, challenges and solutions of these two programs,
and how their history can serve to advise and inform other software projects.
Purpose: d
-Limonene is a natural monoterpene with pronounced chemotherapeutic activity and minimal toxicity in preclinical studies. A
phase I clinical trial to assess toxicity, the maximum tolerated dose (MTD) and pharmacokinetics in patients with advanced
cancer was followed by a limited phase II evaluation in breast cancer. Methods: A group of 32 patients with refractory solid tumors completed 99 courses of d-limonene 0.5 to 12 g/m2 per day administered orally in 21-day cycles. Pharmacokinetics were analyzed by liquid chromatography-mass spectrometry.
Ten additional breast cancer patients received 15 cycles of d-limonene at 8 g/m2 per day. Intratumoral monoterpene levels were measured in two patients. Results: The MTD was 8 g/m2 per day; nausea, vomiting and diarrhea were dose limiting. One partial response in a breast cancer patient on 8 g/m2 per day was maintained for 11 months; three patients with colorectal carcinoma had prolonged stable disease. There were no
responses in the phase II study. Peak plasma concentration (Cmax) for d-limonene ranged from 10.8 ± 6.7 to 20.5 ± 11.2 μM. Predominant circulating metabolites were perillic acid (Cmax 20.7 ± 13.2 to 71 ± 29.3 μM ), dihydroperillic acid (Cmax 16.6 ± 7.9 to 28.1 ± 3.1 μM ), limonene-1,2-diol (Cmax 10.1 ± 8 to 20.7 ± 8.6 μM ), uroterpenol (Cmax 14.3 ± 1.5 to 45.1 ± 1.8 μM ), and an isomer of perillic acid. Both isomers of perillic acid, and cis and trans isomers of dihydroperillic acid were in urine hydrolysates. Intratumoral levels of d-limonene and uroterpenol exceeded the corresponding plasma levels. Other metabolites were trace constituents in tissue. Conclusions:
d-Limonene is well tolerated in cancer patients at doses which may have clinical activity. The favorable toxicity profile supports
further clinical evaluation.
The anti-inflammatory and redox protective effects of the citronellal (CT) were evaluated using in vivo and in vitro tests. Intraperitoneal (i.p.) administration of CT (50, 100, and 200 mg/kg) inhibited (p < 0.05) the carrageenan-induced leukocyte migration to the peritoneal cavity. Additionally, the carrageenan- and arachidonic acid-induced rat hind paw edema was significantly inhibited (p < 0.05) by i.p. administration of 100 and 200 mg/kg of the compound. When the redox activity was evaluated, CT (200 mg/kg) significantly reduced hepatic lipoperoxidation (p < 0.001), as well as oxidation of plasmatic (p < 0.05) and hepatic (p < 0.01) proteins. The results of the present study support the hypothesis that CT possesses anti-inflammatory and redox protective activities. It is suggested that its effects are associated with the inhibition of the enzymes in the arachidonic acid pathway, which prevent cell migration by inhibiting leukotriene production, edema formation and the increase of reactive oxygen species in tissues. Therefore, CT is of potential benefit to manage inflammatory disorders and correlated damages caused by oxidant agents.
Geraniol, an acyclic dietary monoterpene, suppresses prostate cancer growth and enhances docetaxel chemosensitivity in cultured cell or xenograft tumor models. However, the mechanisms of the geraniol action against prostate cancer are largely unknown. In this study, we investigated the cellular and molecular mechanisms of geraniol-induced cell death in PC-3 prostate cancer cells. Among the examined structurally and functionally similar monoterpenes, geraniol potently induced apoptosis and autophagy. Although independent processes, apoptosis and autophagy acted as cooperative partners to elicit geraniol-induced cell death in PC-3 cells. At a molecular level, geraniol inhibited AKT signaling and activated AMPK signaling, resulting in mTOR inhibition. Combined treatment of AKT inhibitor and AMPK activator markedly suppressed cell growth compared to either treatment alone. Our findings provide insight into future investigations that are aimed at elucidating the role of apoptosis and autophagy in prostate cancer therapy and at developing anticancer strategies co-targeting AKT and AMPK.
Despite significant advances in medicine, liver cancer, predominantly hepatocellular carcinoma remains a major cause of death in the United States as well as the rest of the world. As limited treatment options are currently available to patients with liver cancer, novel preventive control and effective therapeutic approaches are considered to be reasonable and decisive measures to combat this disease. Several naturally occurring dietary and non-dietary phytochemicals have shown enormous potential in the prevention and treatment of several cancers, especially those of the gastrointestinal tract. Terpenoids, the largest group of phytochemicals, traditionally used for medicinal purposes in India and China, are currently being explored as anticancer agents in clinical trials. Terpenoids (also called "isoprenoids") are secondary metabolites occurring in most organisms, particularly plants. More than 40 000 individual terpenoids are known to exist in nature with new compounds being discovered every year. A large number of terpenoids exhibit cytotoxicity against a variety of tumor cells and cancer preventive as well as anticancer efficacy in preclinical animal models. This review critically examines the potential role of naturally occurring terpenoids, from diverse origins, in the chemoprevention and treatment of liver tumors. Both in vitro and in vivo effects of these agents and related cellular and molecular mechanisms are highlighted. Potential challenges and future directions involved in the advancement of these promising natural compounds in the chemoprevention and therapy of human liver cancer are also discussed.
Citronellal (CT) is a monoterpenoid and the major constituent of the mixture of terpenoids that give the citronella oil its lemon scent. Citronella oil is widely used around the world for various purposes and is mainly obtained from plants of the Cymbopogon genus, which are known as "lemongrass." Considering these plants have been used worldwide for various medicinal purposes, the interest of researchers to understand the biological activities of monoterpenoids related to the Cymbopogon genus has been increasing. In the present work, we investigated the antinociceptive action and the redox properties of CT. Our results indicate that intraperitoneal injection of CT was effective in reducing nociceptive face-rubbing behavior in both phases of the formalin test, which was also naloxone-sensitive. CT also evoked antinociceptive response in the capsaicin and glutamate tests. The total radical-trapping antioxidant parameter and total antioxidant reactivity assays indicate that CT at doses of 0.1 and 1 mg/mL exerts a significant antioxidant activity, which is probably related to its ability to scavenge superoxide and nitric oxide, but not H(2)O(2) or hydroxyl radicals, as evaluated separately by specific in vitro tests. These results show for the first time the antinociceptive potential of CT and indicate that the antioxidant properties of this compound may rely on its mechanism of biological actions because CT-containing natural products are used to treat various diseases related to oxidative stress and reactive species.
In the female reproductive tract, mammalian sperm undergo a regulated sequence of prefusion changes that “prime” sperm for
fertilization. Among the least understood of these complex processes are the molecular mechanisms that underlie sperm guidance
by environmental chemical cues. A “hard-wired” Ca2+ signaling strategy that orchestrates specific motility patterns according to given functional requirements is an emerging
concept for regulation of sperm swimming behavior. The molecular players involved, the spatiotemporal characteristics of such
motility-associated Ca2+ dynamics, and the relation between a distinct Ca2+ signaling pattern and a behavioral sperm phenotype, however, remain largely unclear. Here, we report the functional characterization
of two human sperm chemoreceptors. Using complementary molecular, physiological, and behavioral approaches, we comparatively
describe sperm Ca2+ responses to specific agonists of these novel receptors and bourgeonal, a known sperm chemoattractant. We further show that
individual receptor activation induces specific Ca2+ signaling patterns with unique spatiotemporal dynamics. These distinct Ca2+ dynamics are correlated to a set of stimulus-specific stereotyped behavioral responses that could play vital roles during
various stages of prefusion sperm-egg chemical communication.
Ca(2+) homeostasis plays a critical role in a variety of cellular processes. We showed previously that stimulation of the prostate-specific G protein-coupled receptor (PSGR) enhances cytosolic Ca(2+) and inhibits proliferation of prostate cells. Here, we analyzed the signaling mechanisms underlying the PSGR-mediated Ca(2+) increase. Using complementary molecular, biochemical, electrophysiological, and live-cell imaging techniques, we found that endogenous Ca(2+)-selective transient receptor potential vanilloid type 6 (TRPV6) channels are critically involved in the PSGR-induced Ca(2+) signal. Biophysical characterization of the current activated by PSGR stimulation revealed characteristic properties of TRPV6. The molecular identity of the involved channel was confirmed using RNA interference targeting TrpV6. TRPV6-mediated Ca(2+) influx depended on Src kinase activity. Src kinase activation occurred independently of G protein activation, presumably by direct interaction with PSGR. Taken together, we report that endogenous TRPV6 channels are activated downstream of a G protein-coupled receptor and present the first physiological characterization of these channels in situ.
Olfactory receptors (ORs) are expressed not only in the sensory neurons of the olfactory epithelium, where they detect volatile substances, but also in various other tissues where their potential functions are largely unknown. Here, we report the physiological characterization of human OR51E2, also named prostate-specific G-protein-coupled receptor (PSGR) due to its reported up-regulation in prostate cancer. We identified androstenone derivatives as ligands for the recombinant receptor. PSGR can also be activated with the odorant beta-ionone. Activation of the endogenous receptor in prostate cancer cells by the identified ligands evoked an intracellular Ca2+ increase. Exposure to beta-ionone resulted in the activation of members of the MAPK family and inhibition of cell proliferation. Our data give support to the hypothesis that because PSGR signaling could reduce growth of prostate cancer cells, specific receptor ligands might therefore be potential candidates for prostate cancer treatment.
Deciphering olfactory encoding requires a thorough description of the ligands that activate each odorant receptor (OR). In mammalian systems, however, ligands are known for fewer than 50 of more than 1400 human and mouse ORs, greatly limiting our understanding of olfactory coding. We performed high-throughput screening of 93 odorants against 464 ORs expressed in heterologous cells and identified agonists for 52 mouse and 10 human ORs. We used the resulting interaction profiles to develop a predictive model relating physicochemical odorant properties, OR sequences, and their interactions. Our results provide a basis for translating odorants into receptor neuron responses and for unraveling mammalian odor coding.
beta-myrcene (MYR) is an acyclic monoterpene found in the essential oils of several useful plants such as lemongrass (Cymbopogon citratus), hop, bay, verbena and others. Recently it has been reported that MYR as well as lemongrass oil blocked the metabolic activation of some promutagens (e.g., cyclophosphamide and aflatoxin B1) in in vitro genotoxicity assays. The present study was performed to evaluate the inhibitory effects of MYR and some other monoterpenoid compounds on microsomal enzymes involved in the activation of genotoxic substances. The effects of MYR and other monoterpenes on the activity of pentoxyresorufin-O-depenthylase (PROD), a selective marker for CYP2B1, was determined in a pool of liver microsomes prepared from phenobarbital-treated rats. The effect of MYR on the activity of ethoxyresorufin-O-deethylase (EROD), a marker for CYP4501A1, was investigated in liver microsomes of untreated rats. Results revealed that MYR had almost no effect on EROD (IC50 > 50 microM), but produced a concentration-dependent inhibition of PROD activity (IC50 =0.14 microM). The analysis of alterations produced by MYR on PROD kinetic parameters (Lineweaver-Burk plot) suggested that inhibition is competitive (Ki = 0.14 microM). The inhibitory effects of seven other monoterpenes on PROD activity (pentoxyresorufin 5 microM) were also studied and the IC50 were as follows: (-)-alpha-pinene, 0.087 microM; (+)-alpha-pinene, 0.089 microM; d-limonene, 0.19 microM; alpha-terpinene, 0.76 microM; citral, 1.19 microM; citronellal, 1.56 microM, and (+/-) camphor, 7.89 microM. The potent inhibitory effects on CYP4502B1 suggest that MYR, and other monoterpenes, interfere with the metabolism of xenobiotics which are substrates for this isoenzyme.
We treated 21 patients in a dose-finding and pharmacokinetic study of the monoterpene perillyl alcohol with the drug given orally in 3 divided doses on a chronic basis. The average number of days that patients remained on study was 48 (range 11-172). Fatigue and low-grade nausea were dose limiting. Using this schedule, a starting dose of 1.6 g/m2 with escalation to 2.1 g/m2 as tolerated is recommended. Two major metabolites were detectable and the mean peak plasma concentrations were 383 microM for perillic acid and 27 microM for dihydroperillic acid. The peak plasma concentration and the metabolite half-life were 2 h and 1 h post ingestion for perillic acid, and 4 h and 2.4 h for dihydroperillic acid, respectively. Stabilization of disease was observed in one of the 16 patients evaluable for response. Many of the gastrointestinal side effects that were poorly tolerated on a chronic basis may be partly related to the soybean oil base used in the current formulation. Further development of perillyl alcohol on this schedule would be facilitated by reformulation of the capsule.
The effect of monoterpene perillyl alcohol (POH) on cell growth, cell cycle progression, and expression of cell cycle-regulatory proteins in estrogen receptor (ER)-positive (KPL-1 and MCF-7) and ER-negative (MKL-F and MDA-MB-231) human breast cancer cell lines was examined. POH inhibited cell proliferation in a dose-dependent manner in all cell lines tested. POH at a dose of 500 micro M had a cytostatic effect, in which growth inhibition was due to accumulation of cells in G1-phase. Cell cycle progression was preceded by a decrease in G1 cyclins (cyclin D1 and E), followed by an increase in p21(Cip1/Waf1) and a decrease in proliferating cell nuclear antigen level. Levels of p53 and cyclin A were unchanged. POH at a dose of 75 mg/kg administered intraperitoneally three times a week throughout the entire 6-week experimental period suppressed orthotopically transplanted KPL-1 tumor cell growth and regional lymph node metastasis in a nude mouse system. POH inhibited both ER-positive and -negative human breast cancer cell growth in vitro, and suppressed growth and metastasis in vivo.
α-Methylfluorene-2-acetic acid (MFA), a new anti-inflammatory agent, enhanced the stimulation of adenylate cyclase activity from guinea pig heart by isoproterenol, epinephrine and norepinephrine, but did not cause increases in either basal or histamine-stimulated activity. Propranolol blocked the effects of isoproterenol plus MFA on heart cyclase activity. MFA did not enhance PGE1- or PGE2-stimulated cyclase activity from guinea pig lung; effects of MFA on isoproterenol-stimulated activity were obscured by a marked inhibition of basal activity. d-MFA and l-MFA were equipotent enhancers of isoproterenol-responsive heart cyclase activity. Increases in isoproterenol-stimulated cyclase activity from heart in the presence of MFA appeared reversible; decreases in basal activity were irreversible. The action of MFA was not due to inhibition of cyclic nueleotide phosphodiesterase activity, nor did MFA appear either to affect catecholamine degradation or to antagonize an endogenous cytoplasmic inhibitor of catecholamine action. It is possible that MFA perturbed the membrane milieu of the cyclase complex so as to have enhanced catecholamine binding to hormone receptors or coupling of the binding event to cyclic AMP synthesis.
Hepatocellular carcinoma (HCC) is the fifth most common cancer in men and seventh in women, accounting for 7 % of all cancers, and the third cause of cancer-related death worldwide. Nearly 90 to 95 % of all HCC occur in the context of known and often preventable risk factors, such as chronic viral hepatitis, alcohol abuse, and metabolic disorders. Although several experimental lines of research support a direct role for hepatitis C virus (HCV) in cancer promotion, cirrhosis is the main risk factor for this tumor, whereas other factors like alcohol and tobacco smoking are clearly able to accelerate HCC development. For this reason, cirrhotic patients with chronic HCV infection are subjected to abdominal ultrasound surveillance every 6 months, aimed at an early diagnosis of HCC to allow curative treatment options. Current strategies to positively impact on HCC incidence rates in HCV patients include prevention of cirrhosis development by avoiding metabolic, pharmacological, or social factors associated with accelerated progression of liver disease, or through virus eradication by interferon-based treatments. Moreover, a successful antiviral treatment has the added benefit of positively impacting on the rate of HCC development also in patients who are already cirrhotic.
Licorice (LE) has been commonly used in traditional Chinese medicine (TCM) for over 4000years to reconcile various drugs and for hepatic disorders. Glycyrrhizin is the main bioactive component isolated from LE herbs. In the present study we examined the effects of glycyrrhizin on pregnane X receptor (PXR)-mediated CYP3A expression and its hepatoprotective activity. Treatment of HepG2 cells with glycyrrhizin resulted in marked increase in both CYP3A4 mRNA and protein levels. The transcriptional activation of the CYP3A4 gene through glycyrrhizin is PXR-dependent, as shown in transient transfection experiments. Glycyrrhizin activates the DNA-binding capacity of the PXR for the CYP3A4 element responding to xenobiotic signals, as measured by the electrophoretic-mobility shift assay (EMSA). These results indicate that the induction of the hepatic CYP3A4 by glycyrrhizin is mediated through the activation of PXR. The next aim of the current study was to determine whether the activation of PXR and induction of CYP3A by glycyrrhizin prevents hepatotoxicity during cholestasis as a mechanism of hepatoprotection. Mice were pretreated with glycyrrhizin prior to induction of intrahepatic cholestasis using lithocholic acid (LCA). Pre-treatment with glycyrrhizin, as well as the PXR activator pregnenolone 16α-carbontrile (PCN), prevents the increase in plasma ALT and AST activity, multifocal necrosis and prevents an increase in a level of serum LCA level in mice, as compared with the results in the mice treated with LCA alone. Activation of the PXR by glycyrrhizin results in induction of CYP3A11 (CYP3A4 for human) expression and inhibition of CYP7A1 through an increase in small heterodimer partner (SHP) expression. Glycyrrhizin regulates the expression of the gene mentioned above to prevent toxic accumulation of bile acids in the liver and it also protects mouse livers from the harmful effects of LCA. In conclusion, PXR-mediated effects on CYP3A and CYP7A may contribute to the hepatoprotective property of glycyrrhizin against LCA-induced liver injury.
To identify the chemical constituents of volatile oil from blood orange (Citrus sinensis (L) Osbeck) and understand the possible mechanisms of inhibition of colon cancer cell proliferation.
Volatile oil was obtained from blood oranges by hydro-distillation. Nineteen compounds were identified by GC-MS and d-limonene was found to be the major component. The blood orange volatile oil was formulated into an emulsion (BVOE) and examined for its effects on viability of colon cancer cells. In addition, experiments were performed to understand the possible mechanism of proliferation inhibition, angiogenesis and metasasis by BVOE.
BVOE exhibited dose-dependent inhibition of cell proliferation and induced apoptosis in the colon cancer cells, as confirmed by flow cytometry. Immunoblotting of colon cancer cells treated with BVOE shows dose-dependent induction of Bax/Bcl2) and inhibition of vascular endothelial growth factor (VEGF). Furthermore, treatment of serum starved SW480 and HT-29 cells with 100μg/ml BVOE suggested the inhibition of VEGF and markers associated with inhibition of angiogenesis. The antiangiogenic activity of BVOE was also confirmed by inhibition of in vitro tube formation in human umbilical vein endothelial cells. Dose-dependent anti-metastasis activity and blockage of vascular endothelial growth factor receptor 1 (VEGFR1) binding following treatment with BVOE were confirmed by cell migration assays and immunoblots to detect decreased expression of matrix metalloproteinases (MMP-9).
The results of this study provide persuasive evidence of the apoptotic and anti-angiogenesis potential of BVOE in colon cancer cells. The extent of induction of apoptosis and inhibition of angiogenesis suggest that BVOE may offer great potential for prevention of cancer and may be appropriate for further studies.
Cytokinesis, the last step during cell division, is a highly coordinated process that involves the relay of signals from both the outside and inside of the cell. We have a basic understanding of how cells regulate internal events, but how cells respond to extracellular cues is less explored. In a systematic RNAi screen of G protein-coupled receptors (GPCRs) and their effectors, we found that some GPCRs are involved in cytokinesis. RNAi knockdown of these GPCRs caused increased binucleated cell formation, and live cell imaging showed that most formed midbodies but failed at the abscission stage. OR2A4 (olfactory receptor, family 2, subfamily A, member 4) localized to cytokinetic structures in cells and its knockdown caused cytokinesis failure at an earlier stage, likely due to effects on the actin cytoskeleton. Identifying the downstream components that transmit GPCR signals during cytokinesis will be the next step and we show that GIPC1 (GIPC PDZ domain containing family, member 1), an adaptor protein for GPCRs, may play a part. RNAi knockdown of GIPC1 significantly increased binucleated cell formation. Understanding the molecular details of GPCRs and their interaction proteins in cytokinesis regulation will give us important clues about GPCRs signaling as well as how cells communicate with their environment during division. © 2012 Wiley Periodicals, Inc.
O(2)-(2,4-dinitro-5-{[2-(12-en-28-β-D- galactopyranosyl-oleanolate-3-yl) -oxy-2-oxoethyl]amino}phenyl)1-(N-hydroxyethylmethylamino)diazen-1-ium-1,2- diolate (NG), a novel PABA/NO-based derivative of oleanolic acid (OA), has been found to show potent antitumor activity both in vivo and in vitro. In the present study, NG could significantly reduce tumor volume and weight in the H22 solid tumor mouse model. Meanwhile, NG showed selective effects on the HepG2 cells including NO generation, cytotoxic effect and apoptosis, which were prevented by hemoglobin (NO scavenger). Moreover, NG-induced apoptosis of HepG2 cells was characteristic of intracellular reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential (Δψm) and enhanced Bax-to-Bcl-2 ratio. The release of apoptotic inducing factor (AIF) and cytochrome c (Cyt c) from mitochondria and the activation of caspase-3, 9 were also detected, indicating that NG may induce apoptosis through a mitochondrial-mediated pathway. Simultaneously, NG treatment could lead to the activation of the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 MAPK but not ERK1/2. Treatment with SP600125 (an inhibitor of JNK) and SB203580 (an inhibitor of p38) prior to NG was found to reverse NG-induced apoptosis. Moreover, it was found that antioxidant N-acetylcysteine (NAC) blocked the induction of apoptosis and partly reversed the activation of JNK and p38, up-regulation of Bax, down-regulation of Bcl-2 and the activation of caspase-3 in NG-treated cells. Taking together, these findings suggest that NO can be released from NG, which induces apoptosis through a ROS/MAPK-mediated mitochondrial pathway.
Hepatocellular carcinoma is one of the most common cancers and lethal diseases in the world. Recently, many researchers focused to identify novel chemotherapeutic agents from natural sources against hepatocarcinogenesis. The diverse therapeutic potential of essential oils has drawn the attention of researchers to test them for anticancer activity, taking advantage of the fact that their mechanism of action is dissimilar to that of chemotherapeutic agents. Earlier reports indicated that essential oil components, especially monoterpenes, have multiple pharmacological effects which could account for the terpene-tumor suppressive activity. In the present study, it is shown that myrtenal, a natural monoterpene, which acts as an antineoplastic agent against diethylnitrosamine induced phenobarbital promoted experimental hepatocellular carcinoma. The results revealed an elevated level of microsomal lipid peroxidation in the liver, which was found to be significantly reduced by myrtenal treatment. On the contrary, the Phase I hepatic drug metabolizing enzymes’ (cytochrome P450, cytochrome b
5, NADPH-cytochrome c reductase, NADH-cytochrome b
5
reductase) levels were decreased and the Phase II enzymes (glutathione-S-transferase, uridine 5′-diphospho-glucuronyl transferase) were increased in carcinogen-administered animals, which were reverted to near normalcy upon myrtenal administration. Our findings also showed that myrtenal restrains the liver cancer by preventing the DEN–PB induced up-regulation of TNF-α protein expression by immunoblot. Furthermore, transmission electron microscopic examination also indicated that myrtenal prevents the carcinogen-induced changes in the architecture of liver tissue and cell structure. Thus, this study shows that myrtenal has the ability to suppress the hepatocellular carcinoma in rats.
Fresh Nagami kumquats (Fortunella margarita) were subjected to hydrodistillation using a Clevenger-type apparatus to obtain volatile oil. The chemical composition of the volatile oil was analyzed by GC-MS using Rtx-5 Sil MS and DB Wax columns. A total of 25 volatile compounds were identified by mass spectra, retention index, and comparison with known standards. The major identified compounds are d-limonene (41.64 %), β-myrecene (16.54 %), linalyl propionate (9.55 %), and germacrene-D (5.93 %) from the Rtx-5 Sil MS column; d-limonene and β-myrecene were also separated as major compounds on the DB wax column. The oil is rich in hydrocarbons (77.41 %) consisting of 60.05 % monoterpenes and 17.36 % sesquiterpenes. Interestingly, oxygenated hydrocarbons (17.6 %) were also found in kumquat volatile oil. Certain volatile compounds were also confirmed by positive chemical ionization and NMR spectra. Further, the volatile oil demonstrated good DPPH radical scavenging activity and antioxidant capacity. Kumquat volatile oil at 200 ppm concentration exhibited 55 %, 61 %, and 63.4 % inhibition of human prostate cancer (LNCaP) cell proliferation at 24, 48, and 72 h, respectively, by cell count assays. Significant increases in expression of bax/bcl2 and p53 proteins confirmed that volatile oil induces apoptosis. In addition, inhibition of inflammatory markers such as NF-κB and Cox-2 was observed. The cleavage of caspase-8 in the LNCaP cells treated with volatile oil demonstrated that apoptosis occurred through an extrinsic pathway. This is the first report of the identification and possible mechanisms of in vitro antiproliferative effects of kumquat volatile components on human prostate cancer (LNCaP) cells.
Thymol, a naturally occurring phenolic compound, has been known for its antioxidant, anti microbial, and anti inflammatory activity. Thymol has also been reported as anti-cancer agent, but its anti-cancer mechanism has not yet been fully elucidated. Thus, we aimed to investigate anticancer activity of thymol on HL-60 (acute promyelotic leukemia) cells. In our study, thymol demonstrated dose dependent cytotoxic effects on HL-60 cells after 24h of exposure. However, thymol did not show any cytotoxic effect in normal human PBMC. The cytotoxic effect of thymol on HL-60 cells appears to be associated with induction of cell cycle arrest at sub G0/G1 phase, and apoptotic cell death based on genomic DNA fragmentation pattern. Thymol also showed significant increase in production of reactive oxygen species (ROS) activity, increase in mitochondrial H(2)O(2) production and depolarization of mitochondrial membrane potential. On performing Western Blot analysis, thymol showed increase in Bax protein level with a concomitant decrease in Bcl2 protein expression in a dose dependent manner. Our study also showed activation of caspase -9, -8 and -3 and concomitant PARP cleavage, which is the hallmark of caspase-dependent apoptosis. Moreover, to rule out the involvement of other mechanisms in apoptosis induction by thymol, we also studied its effect on apoptosis inducing factor (AIF). Thymol induced AIF translocation from mitochondria to cytosol and to nucleus, thus indicating its ability to induce caspase independent apoptosis. We conclude that, thymol-induced apoptosis in HL-60 cells involves both caspase dependent and caspase independent pathways.
Triterpenoids are ubiquitous in the plant kingdom. Recent evidences support the beneficial effects of naturallyoccurring triterpenoids against several types of human diseases, including various cancers. Here, we have summarized the potential of triterpenoids belonging to the lupane, oleanane, ursane, and cucurbitacin groups, and their beneficial effects based on both laboratory and clinical investigations. Anticancer potential of triterpenoids and their anti-inflammatory, anti-proliferative, and pro-apoptotic effects have been discussed both in in vitro and in vivo models. Importantly, a large number of preclinical efficacy studies using chemically-induced, as well as tumor xenograft models provided evidence that both naturally occurring and synthetic derivatives had chemopreventive and therapeutic effects. In this review, we have highlighted several studies on chemopreventive and anticancer potential of triterpenoids based on various preclinical animal models of colon, breast, prostate, and melanoma cancers. Also, we made an attempt in discussing various mechanisms by which triterpenoids regulate various transcription and growth factors, inflammatory cytokines, and intracellular signaling pathways involved in cancer cell proliferation, apoptosis and tumor angiogenesis.
G protein-coupled receptors (GPCRs) belong to a superfamily of cell surface signalling proteins that have a pivotal role in many physiological functions and in multiple diseases, including the development of cancer and cancer metastasis. Current drugs that target GPCRs - many of which have excellent therapeutic benefits - are directed towards only a few GPCR members. Therefore, huge efforts are currently underway to develop new GPCR-based drugs, particularly for cancer. We review recent findings that present unexpected opportunities to interfere with major tumorigenic signals by manipulating GPCR-mediated pathways. We also discuss current data regarding novel GPCR targets that may provide promising opportunities for drug discovery in cancer prevention and treatment.
Three triterpenic acids, oleanolic acid, ursolic acid and maslinic acid, at 2 or 4 μmol/L were used to study their antiangiogenic potential in human liver cancer Hep3B, Huh7 and HA22T cell lines. The effects of these compounds upon the level and/or expression of hypoxia-inducible factor (HIF)-1α, basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), interleukin (IL)-8, urokinase plasminogen activator (uPA), reactive oxygen species (ROS)