Figure 5 - available via license: CC BY-NC
Content may be subject to copyright.
(A) The expression of PLK1 protein in U87R cells receiving different treatments by Western blot analysis. (B) The expression of MGMT protein in T98G, LN-229, U87 and U87R cells by Western blot analysis. (C) The relative expression of PLK1 protein in U87R cells after different treatment by Western blot analysis. (D) The relative expression of MGMT protein in T98G, LN-229, U87 and U87R cells by Western blot analysis. (E) The relative expression of PLK1 mRNA in U87R cells after treatment by qRT-PCR. The concentration of siPLK1 was 1 µg mL −1 . Data are shown as mean ± standard deviation (n = 3), *P < 0.05, **P < 0.01, ***P < 0.001.

(A) The expression of PLK1 protein in U87R cells receiving different treatments by Western blot analysis. (B) The expression of MGMT protein in T98G, LN-229, U87 and U87R cells by Western blot analysis. (C) The relative expression of PLK1 protein in U87R cells after different treatment by Western blot analysis. (D) The relative expression of MGMT protein in T98G, LN-229, U87 and U87R cells by Western blot analysis. (E) The relative expression of PLK1 mRNA in U87R cells after treatment by qRT-PCR. The concentration of siPLK1 was 1 µg mL −1 . Data are shown as mean ± standard deviation (n = 3), *P < 0.05, **P < 0.01, ***P < 0.001.

Source publication
Article
Full-text available
Introduction: Temozolomide (TMZ) is the first-line chemotherapeutic option to treat glioma; however, its efficacy and clinical application are limited by its drug resistance properties. Polo-like kinase 1 (PLK1)-targeted therapy causes G2/M arrest and increases the sensitivity of glioma to TMZ. Therefore, to limit TMZ resistance in glioma, an angi...

Contexts in source publication

Context 1
... transcription and translation of PLK1 were evaluated using qRT-PCR and Western blotting, respectively. QRT-PCR showed that treatment with TMZ-A2PEC/siPLK1 and A2PEC/siPLK1 significantly silenced PLK1 gene expression in glioma cells ( Figure 5E), leading to 61% For personal use only. ...
Context 2
... the cells treated with PBS, free TMZ, and TMZ-A2PEC /NCsiRNA showed no knockdown efficiency. In the Western blotting experiment (Figure 5A), the TMZ-A2PEC/siPLK1 and A2PEC/siPLK1 groups exhibited significantly decreased PLK1 protein levels (by 68% and 50%) compared with that induced in the free siPLK1 group (30%); the control, free TMZ, and TMZ-A2PEC /NCsiRNA groups showed no effect on the PLK1 protein expression ( Figure 5C). These results were consistent with the qRT-PCR data, and both indicated that TMZ-A2PEC /siPLK1 and A2PEC/siPLK1 exerted a strong gene silencing effect on PLK1. ...
Context 3
... the cells treated with PBS, free TMZ, and TMZ-A2PEC /NCsiRNA showed no knockdown efficiency. In the Western blotting experiment (Figure 5A), the TMZ-A2PEC/siPLK1 and A2PEC/siPLK1 groups exhibited significantly decreased PLK1 protein levels (by 68% and 50%) compared with that induced in the free siPLK1 group (30%); the control, free TMZ, and TMZ-A2PEC /NCsiRNA groups showed no effect on the PLK1 protein expression ( Figure 5C). These results were consistent with the qRT-PCR data, and both indicated that TMZ-A2PEC /siPLK1 and A2PEC/siPLK1 exerted a strong gene silencing effect on PLK1. ...
Context 4
... has been reported that the glioma cell lines with high MGMT levels demonstrate drug resistance in the presence of TMZ. 38 To demonstrate that the U87R cells were resistant to the TMZ, the MGMT protein level was evaluated using Western blotting ( Figure 5B). The MGMT protein level in U87R cells (59%) was significantly higher than that in U87 (8%) and LN-229 cells (11%), which were relatively sensitive For personal use only. ...
Context 5
... the TMZ ( Figure 5D). These results suggested that the establishment of TMZ-resistant cell line U87R was successful. ...

Similar publications

Article
Full-text available
Breast cancer is the most common type of malignancy in women, which remains a significant health concern worldwide. Gemcitabine is a frequently applied anticancer pharmacological agent. However, the efficacy of gemcitabine is limited by chemoresistance. In the present study, a combination of reverse transcription quantitative-PCR, cell viability, f...

Citations

... To this end, PLK1 is reported to increase the temozolomide sensitivity in glioma stem cells [91]. Recently, the combination of temozolomide and PLK1 inhibitor has shown synergistic cytotoxicity in glioma cells in vivo [92]. USP9X (ubiquitin-specific peptidase 9 X-linked) is a deubiquitinase which regulates the protein levels of its substrates through proteasomal degradation. ...
Article
Full-text available
Chromatin remodeling is an essential cellular process for organizing chromatin structure into either open or close configuration at specific chromatin locations by orchestrating and modifying histone complexes. This task is responsible for fundamental cell physiology including transcription, DNA replication, methylation, and damage repair. Aberrations in this activity have emerged as epigenomic mechanisms in cancer development that increase tumor clonal fitness and adaptability amidst various selection pressures. Inactivating mutations in AT-rich interaction domain 1A ( ARID1A ), a gene encoding a large nuclear protein member belonging to the SWI/SNF chromatin remodeling complex, result in its loss of expression. ARID1A is the most commonly mutated chromatin remodeler gene, exhibiting the highest mutation frequency in endometrium-related uterine and ovarian carcinomas. As a tumor suppressor gene, ARID1A is essential for regulating cell cycle, facilitating DNA damage repair, and controlling expression of genes that are essential for maintaining cellular differentiation and homeostasis in non-transformed cells. Thus, ARID1A deficiency due to somatic mutations propels tumor progression and dissemination. The recent success of PARP inhibitors in treating homologous recombination DNA repair-deficient tumors has engendered keen interest in developing synthetic lethality-based therapeutic strategies for ARID1A -mutated neoplasms. In this review, we summarize recent advances in understanding the biology of ARID1A in cancer development, with special emphasis on its roles in DNA damage repair. We also discuss strategies to harness synthetic lethal mechanisms for future therapeutics against ARID1A -mutated cancers.
... [435,436] Further surface modifications allow BCP assemblies to enhance the cell penetration and BBB permeability. [437,438] For instance, Kanazawa and co-workers loaded siRNA against TNF-into a composite of PEG-PCL-Tat, which was formed by conjugating the PEG-PCL micelles with a targeting peptide Tat. siRNA delivered by the established nanocarriers through intranasal administration lowered tTNF-production and neurological score of a rat model of cerebral stroke. ...
... [439] Another study carried out by Shi et al. showed that angiopep-2 (A2)-modified PEG-PEI-PCL micelles can deliver siRNA and drugs to brain tumor both in vitro and in vivo. [438] Additionally, the polymersomes have been also used to the codelivery of nucleic acids and other smaller NPs to achieve multiple functions. For example, Lu et al. developed a polymersome to codeliver superparamagnetic iron oxide NPs and siRNA into the NSC, which were subsequently transplanted into the striatum ipsilateral of the ischemic rat brain. ...
Article
Full-text available
Central Nervous System (CNS) diseases, such as Alzheimer's diseases (AD), Parkinson's Diseases (PD), brain tumors, Huntington's disease (HD), and stroke, still remain difficult to treat by the conventional molecular drugs. In recent years, various gene therapies have come into the spotlight as versatile therapeutics providing the potential to prevent and treat these diseases. Despite the significant progress that has undoubtedly been achieved in terms of the design and modification of genetic modulators with desired potency and minimized unwanted immune responses, the efficient and safe in vivo delivery of gene therapies still poses major translational challenges. Various non‐viral nanomedicines have been recently explored to circumvent this limitation. In this review, an overview of gene therapies for CNS diseases is provided and describes recent advances in the development of nanomedicines, including their unique characteristics, chemical modifications, bioconjugations, and the specific applications that those nanomedicines are harnessed to deliver gene therapies.
... In line with this, using siRNA to knockdown heat shock protein 27 (Hsp27), one of the marker proteins known to cause GBM treatment resistance, was reported to enhance the therapeutic effect of resveratrol in glioma cells (Önay Uçar and Şengelen, 2019). In addition, the vascular endothelial diphosphate modified polymer micelle was reported to enhance the efficacy of TMZ and the cellular uptake of siPLK1, of which this polymer micelle wraps TMZ through hydrophobic interaction (Shi et al., 2020). siPLK1 is compounded with TMZ-A2PEC through electrostatic interaction (Shi et al., 2020). ...
... In addition, the vascular endothelial diphosphate modified polymer micelle was reported to enhance the efficacy of TMZ and the cellular uptake of siPLK1, of which this polymer micelle wraps TMZ through hydrophobic interaction (Shi et al., 2020). siPLK1 is compounded with TMZ-A2PEC through electrostatic interaction (Shi et al., 2020). In summary, research on siRNA has achieved great success. ...
Article
Full-text available
Gliomas are central nervous system tumors originating from glial cells, whose incidence and mortality rise in coming years. The current treatment of gliomas is surgery combined with chemotherapy or radiotherapy. However, developing therapeutic resistance is one of the significant challenges. Recent research suggested that small interfering RNA (siRNA) has excellent potential as a therapeutic to silence genes that are significantly involved in the manipulation of gliomas’ malignant phenotypes, including proliferation, invasion, metastasis, therapy resistance, and immune escape. However, it is challenging to deliver the naked siRNA to the action site in the cells of target tissues. Therefore, it is urgent to develop delivery strategies to transport siRNA to achieve the optimal silencing effect of the target gene. However, there is no systematic discussion about siRNAs’ clinical potential and delivery strategies in gliomas. This review mainly discusses siRNAs’ delivery strategies, especially nanotechnology-based delivery systems, as a potential glioma therapy. Moreover, we envisage the future orientation and challenges in translating these findings into clinical applications.
... Glioma cells (U87 cells) were transformed with the luciferase gene (U87-luci). The brain glioma model was established by the stereotactic implantation of U87-luci cells (Shi et al., 2020). After that, 1 × 10 5 U87-luci cells in 5 μl of L15 medium were injected for 10 min and allowed to stay for 5 min into the right striatum with microsyringe before removing. ...
Article
Full-text available
Glioblastoma (GBM) is one of the most lethal forms of human cancer, with very few long-term survivors. In addition to surgery, chemotherapy is still an important strategy. Unfortunately, GBM chemotherapy faces two main challenges: first, in GBM, epidermal growth factor receptor (EGFR) overexpression results in chemoresistance; second, temozolomide (TMZ) lacks target specificity, which can lead to a reduction in the concentration and side effects in GBM. Nowadays, with the development of nanomedicine systems for applications in tumor therapies, increasing anticancer efficacy and reducing side effects with multi-drug delivery are huge advantages. In this study, pH-sensitive and GBM-targeting nanovesicle (Tf-PEG-PAE(SS)) was fabricated. The chemotherapy drug (TMZ) and EGFR inhibitor (EGFR-siRNA) were co-encapsulated in the nanocarrier, and their anticancer outcomes were investigated in detail. In vitro experiments have shown that the nanocarrier transports TMZ and EGFR-siRNA efficiently into U87 cells, causing a vigorous apoptotic response by silencing the proliferative EGFR gene and increasing the drug concentration of TMZ simultaneously. An experimental study in mice bearing orthotropic glioma revealed that the accumulated nanocarriers in the tumor site could inhibit the tumor growth and prolong the mice survival remarkably through the intracranial injection of Tf-PEG-PAE(SS)/TMZ@siEGFR. The drug co-delivery system could extend the blood circulation time and offer a new strategy to treat glioblastoma.
... At present, the standard treatment option for glioma is surgical resection combined with radiotherapy and chemotherapy (16). However, the long-term therapeutic efficacy is limited, where the main reasons are as follows: i) Due to ...
... In addition, TMZ is a small molecule and lipophilic substance that can be taken orally and readily traverses through the BBB (33,34). Data from previous preclinical studies (16,27,(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51) (Table I) showed that it can exert anticancer activity. Wang et al (35) treated C6 cells with TMZ (250-1,000 µM) for 24, 48 and 72 h. ...
... Inhibition of PLK1 activity can lead to cell cycle arrest and increase apoptosis of glioma cells. Shi et al (16) previously prepared a polymer micelle modified by A2 (A2PEC). These micelles in turn encapsulated TMZ and small interfering RNA (siRNA) targeting PLK1 (TMZ-A2PEC/siPLK), which were used in U87 and LN-299 glioma cells. ...
Article
Glioma is the most common primary intracranial malignancy in the central nervous system. At present, the most important treatment option is surgical resection of the tumor combined with radiotherapy and chemotherapy. The principle of operation is to remove the tumor to the maximal extent on the basis of preserving brain function. However, prominent invasive and infiltrative proliferation of glioma tumor cells into the surrounding normal tissues frequently reduces the efficacy of treatment. This in turn worsens the prognosis, because the tumor cannot be completely removed, which can readily relapse. Chemotherapeutic agents when applied individually have demonstrated limited efficacy for the treatment of glioma. However, multiple different chemotherapeutic agents can be used in combination with other treatment modalities to improve the efficacy while circumventing systemic toxicity and drug resistance. Therefore, it is pivotal to unravel the inhibitory mechanism mediated by the different chemotherapeutic drugs on glioma cells in preclinical studies. The aim of the present review is to provide a summary for understanding the effects of different chemotherapeutic drugs in glioma, in addition to providing a reference for the preclinical research into novel chemotherapeutic agents for future clinical application.
... At present, no curative treatment is available for GBM and the most used first-line drug, temozolomide (TMZ), is only able to cause an increase in the life expectancy of the treated patients, though this is still not satisfactory [4]. Therefore, new drugs are urgently needed for determining their possible employment in therapeutic protocols for anti-GBM treatments, also tackling important issues of the GBM management, such as the development of drug resistance [5][6][7][8][9][10]. ...
Article
Full-text available
Glioblastoma multiforme (GBM) is a lethal malignant tumor accounting for 42% of the tumors of the central nervous system, the median survival being 15 months. At present, no curative treatment is available for GBM and new drugs and therapeutic protocols are urgently needed. In this context, combined therapy appears to be a very interesting approach. The isothiocyanate sulforaphane (SFN) has been previously shown to induce apoptosis and inhibit the growth and invasion of GBM cells. On the other hand, the microRNA miR-15b is involved in invasiveness and proliferation in GBM and its inhibition is associated with the induction of apoptosis. On the basis of these observations, the objective of the present study was to determine whether a combined treatment using SFN and a peptide nucleic acid interfering with miR-15b-5p (PNA-a15b) might be proposed for increasing the pro-apoptotic effects of the single agents. To verify this hypothesis, we have treated GMB U251 cells with SFN alone, PNA-a15b alone or their combination. The cell viability, apoptosis and combination index were, respectively, analyzed by calcein staining, annexin-V and caspase-3/7 assays, and RT-qPCR for genes involved in apoptosis. The efficacy of the PNA-a15b determined the miR-15b-5p content analyzed by RT-qPCR. The results obtained indicate that SFN and PNA-a15b synergistically act in inducing the apoptosis of U251 cells. Therefore, the PNA-a15b might be proposed in a “combo-therapy” associated with SFN. Overall, this study suggests the feasibility of using combined treatments based on PNAs targeting miRNA involved in GBM and nutraceuticals able to stimulate apoptosis.
... Moreover, the nanovector was designed with a redox-responsive feature to trigger the intracellular release of its payload. In the same year, a combination of Temozolomide and PLK1 siRNA by Angiopep-2-modified PEG-PEI-PCL micelles produced enhanced drug efficacy in glioma [133]. ...
Article
Full-text available
Nanotechnology has opened up a world of possibilities for the treatment of brain disorders. Nanosystems can be designed to encapsulate, carry, and deliver a variety of therapeutic agents, including drugs and nucleic acids. Nanoparticles may also be formulated to contain photosensitizers or, on their own, serve as photothermal conversion agents for phototherapy. Furthermore, nano-delivery agents can enhance the efficacy of contrast agents for improved brain imaging and diagnostics. However, effective nano-delivery to the brain is seriously hampered by the formidable blood–brain barrier (BBB). Advances in understanding natural transport routes across the BBB have led to receptor-mediated transcytosis being exploited as a possible means of nanoparticle uptake. In this regard, the oligopeptide Angiopep-2, which has high BBB transcytosis capacity, has been utilized as a targeting ligand. Various organic and inorganic nanostructures have been functionalized with Angiopep-2 to direct therapeutic and diagnostic agents to the brain. Not only have these shown great promise in the treatment and diagnosis of brain cancer but they have also been investigated for the treatment of brain injury, stroke, epilepsy, Parkinson’s disease, and Alzheimer’s disease. This review focuses on studies conducted from 2010 to 2021 with Angiopep-2-modified nanoparticles aimed at the treatment and diagnosis of brain disorders.
... Gliomas are the most common primary malignancy of the central nervous system (Briançon-Marjollet et al., 2010;Deluche et al., 2019;Shi et al., 2020a). DUXAP10 has been indicated to be highly expressed in glioma cell lines (HS683, U251, U373, U87, T98G Notably, it was found that DUXAP10 was involved in facilitating the stem cell-like properties of glioma U251 and T98G cells by increasing the expression of Sox2, CD133, Oct4 stemness markers, the ability of tumorsphere formation, and the activity of ALDH, which closely aligns with the CSC induction mentioned in the above chronic Cd exposure study on lung cancer. ...
... Cell proliferation and apoptosis are fundamental for normal cell growth and development. Abnormal cell growth is a key marker for cancer (Shi et al., 2020a;Go et al., 2021;. It has been shown that microRNA-1914 could increase the effect of DUXAP10 on cell proliferation and apoptosis through activation of the GPR39-mediated PI3K/AKT/mTOR pathway in HCC Hep3B and MHCC-97L (Sun et al., 2019) cells ( Figure 2). ...
Article
Full-text available
Cancer is one of the most prevalent and deadliest diseases globally, with an increasing morbidity of approximately 14 million new cancer cases per year. Identifying novel diagnostic and prognostic biomarkers for cancers is important for developing cancer therapeutic strategies and lowering mortality rates. Long noncoding RNAs (lncRNAs) represent a group of noncoding RNAs of more than 200 nucleotides that have been shown to participate in the development of human cancers. The novel lncRNA DUXAP10 was newly reported to be abnormally overexpressed in several cancers and positively correlated with poor clinical characteristics of cancer patients. Multiple studies have found that DUXAP10 widely regulates vital biological functions related to the development and progression of cancers, including cell proliferation, apoptosis, invasion, migration, and stemness, through different molecular mechanisms. The aim of this review was to recapitulate current findings regarding the roles of DUXAP10 in cancers and evaluate the potential of DUXAP10 as a novel biomarker for cancer diagnosis, treatment, and prognostic assessment.
... Shi and colleagues (2020) [115] also developed a PM to codelivery TMZ and another siRNA targeting the polo-like kinase 1 (PLK1) for enhancing the sensitivity of GBM cells to TMZ and causes G2/M arrest. ...
Article
Glioblastoma multiforme (GBM) is the most common primary brain cancer. GBM has aggressive development, and the pharmacological treatment remains a challenge due to GBM anatomical characteristics’ (the blood-brain barrier tumor microenvironment) and the increasing resistance to marketed drugs, such as temozolomide (TMZ), the first-line drug for GBM treatment. Due to physical-chemical properties such as short half-life time and the increasing resistance shown by GBM cells, high doses and repeated administrations are necessary, leading to significant adverse events. This review will discuss the main molecular mechanisms of TMZ resistance and the use of functionalized nanocarriers as an efficient and safe strategy for TMZ delivery. GBM-targeting nanocarriers are an important tool for the treatment of GBM, demonstrating to improve the biopharmaceutical properties of TMZ and repurpose its use in anti-GBM therapy. Technical aspects of nanocarriers will be discussed, and biological models highlighting the advantages and effects of functionalization strategies in TMZ anti-GBM activity. Finally, conclusions regarding the main findings will be made in the context of new perspectives for the treatment of GBM using TMZ as a chemotherapy agent, improving the sensibility and biological anti-tumor effect of TMZ through functionalization strategies.
... It could knock down PLK1 mRNA expression to 60%. Silencing protein expression was followed by low PKL1 protein expression [149]. ...
Article
Glioblastoma multiforme (GBM) is abnormal cell proliferation of glial cells. GBM is the grade IV glioma brain cancer which is life-threatening to many individuals affected by this cancer. The DNA alkylating agent Temozolomide (TMZ) has the distinctiveness of being FDA approved anticancer drug for the first line treatment for GBM. However, treatment of GBM still remains a challenge. This is attributed to TMZ's toxic nature, severe side effects, and fast degradation in vivo. In addition, the lack of targeting ability increases the chances of systemic toxicities. A nano enabled targeted delivery system not only improves the efficiency of TMZ by making it cross the blood brain barrier, have specificity to target, but also reduces toxicity to healthy tissues. Over the last decade the significant advances in the area of nanotechnology applied to medicine have developed many multifunctional therapeutics. In this context, the present review article comprehends the significant progress in the field of TMZ loaded nanocarriers showing promise for futuristic nanomedicine therapies in treating GBM.