[show abstract][hide abstract] ABSTRACT: In 54 stage I and II human lung adenocarcinomas, HuR and PTHrP levels were positively correlated and the PTHr-HuR status of the tumor was an independent prognostic marker of the clinical outcomes of patients. The possibility that HuR could upregulate PTHrP expression in lung adenocarcinoma was investigated by immunohistochemical, Western blot and RT-PCR analyses in HCC44 and DV90 human lung adenocarcinoma cell lines. In both cell lines, knockdown of HuR by specific siRNAs reduced PTHrP mRNAs and both cellular and secreted protein. Moreover, it inhibited cell growth and induced cell apoptosis, as revealed by the increase of caspase-3 activity. These effects were partially rescued by the addition of exogenous PTHrP (1-34). Analysis by actinomycin D assay revealed that in both cell lines HuR silencing produced a decrease of PTHrP mRNA half-life by about 70%. These findings add PTHrP to the list of lung cancer-associated genes, whose mRNA is stabilized by HuR.
Histology and histopathology 04/2013; · 2.28 Impact Factor
[show abstract][hide abstract] ABSTRACT: A large body of evidence has emerged over the past years to show the critical role played by inflammation in the pathogenesis of several diseases including some cardiovascular, neoplastic, and neurodegenerative diseases, previously not considered inflammation-related. The anti-inflammatory action of ω-3 polyunsaturated fatty acids (PUFAs), as well as their potential healthy effects against the development and progression of the same diseases, has been widely studied by our and others' laboratories. As a result, a rethinking is taking place on the possible mechanisms underlying the beneficial effects of ω-3 PUFAs against these disorders, and, in particular, on the influence that they may exert on the molecular pathways involved in inflammatory process, including the production of inflammatory cytokines and lipid mediators active in the resolving phase of inflammation. In the present review we will summarize and discuss the current knowledge regarding the modulating effects of ω-3 PUFAs on the production of inflammatory cytokines and proresolving or protective lipid mediators in the context of inflammatory, metabolic, neurodegenerative, and neoplastic diseases.
BioMed research international. 01/2013; 2013:743171.
[show abstract][hide abstract] ABSTRACT: n-3 polyunsaturated fatty acids exert growth-inhibitory and pro-apoptotic effects in colon cancer cells. We hypothesized that the anti-apoptotic glucose related protein of 78kDa (GRP78), originally described as a component of the unfolded protein response in endoplasmic reticulum (ER), could be a molecular target for docosahexaenoic acid (DHA) in these cells. GRP78 total and surface overexpression was previously associated with a poor prognosis in several cancers, whereas its down-regulation with decreased cancer growth in animal models. DHA treatment induced apoptosis in three colon cancer cell lines (HT-29, HCT116 and SW480), and inhibited their total and surface GRP78 expression. The cell ability to undergo DHA-induced apoptosis was inversely related to their level of GRP78 expression. The transfection of the low GRP78-expressing SW480 cells with GRP78-GFP cDNA significantly induced cell growth and inhibited the DHA-driven apoptosis, thus supporting the essential role of GRP78 in DHA pro-apoptotic effect. We suggest that pERK1/2 could be the first upstream target for DHA, and demonstrate that, downstream of GRP78, DHA may exert its proapoptotic role by augmenting the expression of the ER resident factors ERdj5 and inhibiting the phosphorylation of PKR-like ER kinase (PERK), known to be both physically associated with GRP78, and by activating caspase-4. Overall, the regulation of cellular GRP78 expression and location is suggested as a possible route through which DHA can exert pro-apoptotic and antitumoral effects in colon cancer cells.
Biochimica et Biophysica Acta 08/2012; 1822(11):1762-72. · 4.66 Impact Factor
[show abstract][hide abstract] ABSTRACT: It has been hypothesized that pro-inflammatory cytokines may play a pathogenic role in Alzheimer's disease (AD), and that n-3 polyunsaturated fatty acids may be protective against the development and progression of this disease. A reduced release of inflammatory cytokines by lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs) from AD patients dietary supplemented with a mixture of eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) was recently reported. On this basis, we investigated the possible differential effects of the two purified fatty acids on inflammatory cytokine release, a subject still not explored, even though of great pharmacological interest. We treated in vitro phytohaemagglutinin (PHA)- or LPS-stimulated PBMCs from AD patients and age-matched healthy controls (HCs) with purified EPA or DHA. Higher pro- to anti-inflammatory cytokine ratios, indicative of a pro-inflammatory profile, were observed in PHA-stimulated PBMCs from AD patients in basal conditions. The addition of both EPA and DHA markedly reduced the cytokine release, with DHA showing always a more prominent effect than EPA. However, whereas DHA reduced only the high IL-1β/IL-10 ratio, EPA was able to reduce also the IL-6/IL-10 ratio. In stimulated PMBCs from HCs the reducing effect on cytokine release was not always observed, or observed at a lower degree. In conclusion, whereas DHA appeared more powerful in inhibiting each single inflammatory cytokine, the proinflammatory profile of the AD patients' cells was better reverted by EPA to a profile more similar to that found in HCs. A combination of both the fatty acids, seems to be still the best solution.
Current Alzheimer research 01/2012; 9(8):913-23. · 4.97 Impact Factor
[show abstract][hide abstract] ABSTRACT: The pro-inflammatory phenotype accompanying melanoma progression includes an enhanced expression of cyclooxygenase-2 (COX-2), which plays an important role in the acquisition of apoptosis resistance, and is a suitable target for melanoma prevention and therapy. We observed that the WM266-4 metastatic melanoma cell line showed a constitutive COX-2 expression higher than that of the primary WM115 cells, an increased cytosolic level of the COX-2 messenger RNA (mRNA)-stabilizer human antigen R (HuR) and a lower susceptibility to basal apoptosis. The transfection of HuR siRNA induced apoptosis and reduced COX-2 protein abundance in both the cells. The same effects were observed treating the cells with the n-3 polyunsaturated fatty acid docosahexaenoic acid (DHA), which reduced the cytoplasmic location and expression of HuR and, correspondently, decreased COX-2 protein expression and induced apoptosis. DHA also decreased the expression and stability of COX-2 mRNA, increased the β-catenin expression in the nuclei and reduced it in the cytosol, where it forms a complex with HuR and COX-2 mRNA. DHA had also a pro-differentiating effect, which is compatible with the nuclear translocation of β-catenin. These findings allow us to associate for the first time the constitutive expression of COX-2 in melanoma cells to the HuR-mediated stabilization of its mRNA and suggest that also β-catenin may play a role in HuR-mediated COX-2 stabilization in these cells. The data demonstrate that the HuR-mediated stabilization of COX-2 may represent a target of DHA action in melanoma cells and suggest the application of DHA in the prevention and therapy of melanoma.
[show abstract][hide abstract] ABSTRACT: There is some evidence to support the toxicity of polyunsaturated fatty acids (PUFAs) and their oxidative products, suggesting their involvement in the pathogenesis of different chronic diseases, including cancer. It has been shown that products of PUFA oxidation may exert a carcinogenic action by forming mutagenic adducts with DNA. However, a large amount of evidence accumulated over several decades has indicated the beneficial effects of administration of n-3 PUFAs in the prevention and therapy of a series of diseases. In particular, there is much evidence that n-3 PUFAs exert anti-inflammatory and antineoplastic effects, whereas n-6 PUFAs promote inflammation and carcinogenesis. In our tissues, both of the two classes of PUFAs can be converted into bioactive products, incorporated into membrane phospholipids or bound to membrane receptors, where they may alter, often in opposite ways, transduction pathways and affect important biological processes, such as cell death and survival, inflammation, and neo-angiogenesis. In the present review, we intend to shed light on the paradox of the coexisting healthy and toxic effects of n-3 PUFAs, focusing on their possible pro-oxidant cytotoxic and carcinogenic effect, in order to understand if their increased intake, recommended by a number of health agencies worldwide and promoted by nutraceutical producers, may or may not represent a hazard to human health.
Chemical Research in Toxicology 09/2011; 24(12):2093-105. · 3.67 Impact Factor
[show abstract][hide abstract] ABSTRACT: As the concepts of pharmaconutrition are receiving increasing attention, it seems essential to clearly assess the effects of specific dietary compounds in specific groups of patients or clinical conditions. We are herein interested in better defining the differential anti-neoplastic effects of the two major n-3 long chain polyunsaturated fatty acids present in fish oil, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The efficiency of these fatty acids represents a subject of intense interest and debate, and whereas plenty of preclinical studies have strongly demonstrated their preventive and therapeutic effect in different kinds of cancers, the results of the epidemiologic studies are still controversial, and only a few trials have been performed. It has been reported that EPA and DHA may act either through the same or different mechanisms, thus suggesting that a differential efficacy could exist. At present, however, this point has not been clarified, although its better comprehension would allow a more proper and effective use of these fatty acids in the human interventional studies. In an attempt to elucidate this aspect we have herein analyzed the data obtained in the studies which have directly compared the antitumor effects of separate treatments with EPA or DHA. Most of the in vitro data indicate DHA as the more powerful antineoplastic agent. However, an equivalent efficiency of EPA and DHA is suggested by the few in vivo studies. Possible reasons for this discrepancy are discussed and pathways of cell growth that could be differentially influenced by EPA and DHA are described.
Current Medicinal Chemistry 08/2011; 18(26):4065-75. · 4.07 Impact Factor
[show abstract][hide abstract] ABSTRACT: The dramatic increase in the incidence of nonmelanoma skin cancer over the last decades has been related to the augmented exposure to ultraviolet (UV) radiation (UVR). It is known that apoptosis is induced as a protective mechanism after the acute irradiation of keratinocytes, whereas apoptotic resistance and carcinogenesis may follow the chronic exposure to UVR. We found that not all the human keratinocytes lines studied underwent apoptosis following acute exposure to UVR (10-60 mJ/cm(2)). Whereas UVR induced apoptosis in the HaCaT cells, NCTC 2544 and nr-HaCaT cells showed apoptosis resistance. The cytokeratin pattern of the apoptosis-resistant cells indicated that they possessed a degree of differentiation lower than that of HaCaT cells. They also showed an enhanced expression of cyclooxygenase-2 (COX-2), an early marker of carcinogenesis in various tissues, including skin. n-3 polyunsaturated fatty acids have drawn increasing interest as nutritional factors with the potential to reduce UVR carcinogenesis, and since they are apoptosis inducers and COX-2 inhibitors in cancer cells, we investigated the ability of n-3 polyunsaturated fatty acids to influence the resistance to UVR-induced apoptosis in keratinocytes. We observed that docosahexaenoic acid (DHA) reverted the resistance of nr-HaCaT cells to UVR-induced apoptosis, increasing the Bax/Bcl-2 ratio and caspase-3 activity, and reduced COX-2 levels by inhibiting the expression of the human antigen R (HuR), a known COX-2 mRNA stabilizer in keratinocytes. The transfection of nr-HaCaT cells with HuR siRNA mimicked the proapoptotic effect of DHA. Overall, our findings further support the role of DHA as a suitable anticarcinogenic factor against nonmelanoma skin cancers.
The Journal of nutritional biochemistry 12/2010; 22(9):874-85. · 4.29 Impact Factor
[show abstract][hide abstract] ABSTRACT: The beneficial health effects of n-3 polyunsaturated fatty acids (PUFAs) from marine fish are widely recognized. However, concern exists about the safety of fish intake, since the water in which they live is often highly contaminated. In the present work we analyzed the n-3 PUFA and α- and γ-tocopherol composition of 12 fish species from an artificial lake located in an Italian region far from metropolitan and industrial sites, to evaluate whether the n-3 PUFA content could be comparable to that of marine fish, and whether the levels of the antioxidant tocopherols were enough to ensure a correct preservation of the fish after being caught. Moreover, we studied the chemical and physical features of the lake water and the levels of chemical pollutants present. The benthic macro-invertebrates representing the main food source for freshwater fish were also analyzed. The good chemical–physical quality of the water, as well as the n-3 PUFA and tocopherol levels in the fish, would constitute the basis for advising the dietary usage of these fish to increase intakes of these important nutrients. Pregnant or lactating women, and infants after weaning, in particular, could benefit from eating them, since safe and adequate n-3 PUFA dietary supplementation is required to guarantee the correct pre- and post-natal development of cerebral tissues in children.
Journal of Food Composition and Analysis. 01/2010;
[show abstract][hide abstract] ABSTRACT: Different intervention trials have been so far conducted and others are ongoing to evaluate the effect of increased intake of n-3 polyunsaturated fatty acids (PUFAs) in the prevention of several disorders affecting lungs and airways. They have been focused on chronic obstructive pulmonary disease, acute respiratory distress syndrome, acute lung injury, pulmonary fibrosis, alteration of lung function in cystic fibrosis, as well as asthma and cachexia in lung cancer patients. Their outcomes are not always consistent, but, if beneficial effects were observed, they have been related mainly to the anti-inflammatory action of n-3 PUFAs. On the contrary, trials investigating their effects on the development and progression of lung cancer are still not available. This in spite of the huge number of equivalent studies performed on other kind of cancers (breast, colon and prostate cancer), which share with lung cancer the highest incidence in Western countries and an elevated sensitivity to chemoprevention. Contrasting results were also obtained by the few epidemiological studies available on lung cancer. However, different experimental studies, performed in vivo and in vitro, provided strong indications of the anti-tumor action of n-3 PUFAs against lung cancer, and identified molecular mechanisms for their action. In this review our effort will concentrate in critically reviewing the current evidence for the beneficial effect of n-3 PUFAs in inflammatory and neoplastic disorders of lungs and airways, and in identifying possible molecular mechanisms underlying their effects.
Current Medicinal Chemistry 01/2010; 17(29):3358-76. · 4.07 Impact Factor
[show abstract][hide abstract] ABSTRACT: Colon cancer represents one of the most frequent forms of cancer worldwide. There is plenty of evidence to support the notion
that chemoprevention is a major component of colon cancer control, and that dietary fats influence the rate of incidence of
this kind of cancer. In particular, a variety of experimental studies conducted on animals subject to chemical carcinogenesis
of colon, transplanted with colon cancer cells, or representing a genetic model of colon cancer have demonstrated the ability
of diets at high content of ω-3 polyunsaturated fatty acids (PUFAs) to reduce the risk, growth, and progression of colon cancer.
Several of these studies have also emphasized the importance of a reduced dietary ω-6 PUFA/ω-3 PUFA ratio to diminish the
risk. The beneficial anti-tumor effects of ω-3 PUFAs have been also largely demonstrated in colon cancer cells treated in
vitro with these fatty acids. The synergic action of combinations of ω-3 PUFAs and other anti-neoplastic agents has also been
demonstrated both in vivo and in vitro. On the contrary, just a few human interventional trials have been conducted so far,
but there is complete agreement among them and with the experimental studies on the anti-tumor efficacy of increased dietary
intakes of ω-3 PUFAs.
Keywordsω-3 PUFAs-Growth-inhibiting effect-Colon cancer-Experimental studies-Interventional trials
[show abstract][hide abstract] ABSTRACT: The protective role of dietary n-3 polyunsaturated fatty acids (PUFAs) against cardiovascular diseases has been partly related to their ability to modulate the risk condition known as "endothelial dysfunction", by reverting the endothelial alterations associated to it (reduced vascular reactivity, the proinflammatory state, and the prothrombotic properties). Moreover, vasculature represents the target for inhibition of pathologic neo-angiogenesis by n-3 PUFAs. This effect is believed to contribute to the beneficial action of these fatty acids against disorders which recognize neovascularization as a crucial pathogenetic step for their development, such as cancer and age-related macular degeneration (AMD). Many epidemiological studies have been conducted to evaluate the association between the intake of these fatty acids and the risk of developing cancer or AMD, even though contrasting and not definitive results have been obtained. Conversely, plenty of preclinical and in vitro experimental studies have provided evidence for the anti-angiogenic effects of n-3 PUFAs, mainly studying neo-angiogenesis in general (using normal endothelial cells in vitro) or as a step of cancer growth. The main aim of this review is to critically review the current evidence for the inhibition of the neo-angiogenic process exerted by n-3 PUFAs in cancer and AMD, and to identify possible molecular mechanisms that might contribute to their beneficial effects.
Current Medicinal Chemistry 11/2009; 16(34):4511-26. · 4.07 Impact Factor
[show abstract][hide abstract] ABSTRACT: It has recently become clear the role played by alterations in apoptosis during the development of several chronic diseases (i.e. inflammatory, neurodegenerative and neoplastic pathologies). For this reason, the research for possible therapeutic strategies involving the modulation of the apoptotic pathways has attracted considerable interest in the past few years. In particular, it has been shown that apoptosis may be induced or inhibited by a variety of nutritional compounds providing health benefits. The aim of this review is to examine the ability of different dietary polyunsaturated fatty acids (PUFAs) to induce apoptosis, especially in the cancer field. The molecular effects of different PUFAs found in dairy products, meat, fish, vegetable seeds and oils, and known to affect the incidence and progression of cancer and other chronic diseases, will be analyzed. To this aim, our effort will concentrate in critically reviewing the published works concerning the effects of: (a) the n-6 PUFAs gamma-linolenic acid, arachidonic acid, and conjugated linoleic acid; (b) the n-3 PUFAs eicosapentaenoic acid and docosahexaenoic acid on the apoptotic process. We will also pay attention to the recent findings regarding the possible role of PUFAs as regulators of the endoplasmic reticulum stress-pathway of apoptosis.
[show abstract][hide abstract] ABSTRACT: Many data support the beneficial effect of n-3 polyunsaturated fatty acids (PUFAs) as chemopreventive and chemotherapeutic agents in the treatment of several chronic pathologies including cancer. Different molecular mechanisms have been proposed to explain their effects, including alterations in arachidonic acid oxidative metabolism and metabolic conversion of n-3 PUFAs to novel discovered bioactive derivatives; modification of oxidative stress; changes in cell membrane fluidity and structure and altered metabolism and function of membrane proteins. Considerable knowledge has been recently gathered on the possible beneficial effects of n-3 PUFAs administered in combination with different antineoplastic drugs and radiotherapy against melanoma, leukemia, neuroblastoma, and colon, breast, prostate, and lung cancer. The efficacy of these combinations has been demonstrated both in vivo and in vitro, and clinical trials have also been conducted. The aim of this review is to analyze all the n-3 PUFA combinations investigated so far, their efficacy, and the possible molecular mechanisms involved. It would be highly auspicable that the detailed analysis of the literature in this field could further support the common use of n-3 PUFAs in combination with other chemopreventive agents and warrant more clinical investigations designed to test the effectiveness of n-3 PUFA treatments coupled with conventional antineoplastic therapies.
Nutrition and Cancer 02/2009; 61(3):287-301. · 2.70 Impact Factor
[show abstract][hide abstract] ABSTRACT: Different agents able to modulate apoptosis have been shown to modify the expression of the MAP-kinase-phosphatase-1 (MKP-1). The expression of this phosphatase has been considered a potential positive prognostic factor in lung cancer, and smoke was shown to reduce the levels of MKP-1 in ferret lung. Our aim was to assess whether the n-3 polyunsaturated fatty acid docosahexaenoic acid (DHA), known to inhibit the growth of several cancer cells mainly inducing apoptosis, may exert pro-apoptotic effect in lung cancer cells by modifying MKP-1 expression. We observed that DHA increased MKP-1 protein and mRNA expression and induced apoptosis in different lung cancer cell lines (mink Mv1Lu adenocarcinoma cells, human A549 adenocarcinoma and human BEN squamous carcinoma cells). We inhibited the pro-apoptotic effect of DHA by treating the cells with the phosphatase inhibitor Na(3)VO(4) or by silencing the MKP-1 gene with the specific siRNA. This finding demonstrated that the induction of apoptosis by DHA involved a phosphatase activity, specifically that of MKP-1. DHA reduced also the levels of the phosphorylated MAP-kinases, especially ERK1/2 and p38. Such an effect was not observed when the MKP-1 gene was silenced. Altogether, the data provide evidence that the DHA-induced overexpression of MKP-1 and the resulting decrease of MAP-kinase phosphorylation by DHA may underlie the pro-apoptotic effect of this fatty acid in lung cancer cells. Moreover, they support the hypothesis that DHA may exert chemopreventive action in lung cancer.
[show abstract][hide abstract] ABSTRACT: Elderly dementia is rising dramatically in Western countries. In particular, the irreversible memory impairment, continuous cognitive decline and behavioural disturbances present in Alzheimer's disease patients make this neurodegenerative disorder highly disabiliting. Different epidemiological studies and experimental researches on transgenic mouse models suggest that dietary consumption of the two main long chain n-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may modify the risk and progression of this neurodegenerative disorder. In addition, decreased blood levels of n-3 PUFAs have been associated with this disease in humans. In particular, among n-3 PUFAs, DHA is known to be the most prevalent PUFA in neuronal tissues. Animals specifically deficient in dietary n-3 PUFAs have shown to possess low DHA content in their membranes and impaired learning ability. Moreover, studies on non breast-fed infants have shown that DHA added to formula milk augments the levels of this fatty acid in infant blood improving their mental development. The potential mechanisms by which these fatty acids may function in normal neuronal activity and in neurodegenerative disease prevention and treatment are not well understood, even though these topics are now under investigation in numerous laboratories. In this review the current knowledge about the molecular mechanisms by which n-3 PUFAs are thought to regulate neuronal function, survival and degeneration will be examined. Since the pathological neuronal lesions of Alzheimer disease have been pathogenetically related to alterations of inflammatory and survival/apoptotic responses, molecular modulation of these pathways by n-3 PUFAs in neuronal tissues and cells will be particularly considered.
Current Signal Transduction Therapy 08/2008; 3(3):152-157. · 0.45 Impact Factor
[show abstract][hide abstract] ABSTRACT: Zirconia, a biomaterial widely used in dentistry, has recently attracted much attention for its mechanical strength and toughness. Previously, its lack of mutagenic and carcinogenic power was reported. We describe here other essential aspects to be taken into account to define in vitro the biocompatibility of a material: the growth rate, viability, and adhesion capacity of normal stabilized cells growing on it. To this aim, immortalized RAT-1 fibroblasts, growing either on zirconia and on feldspatic (FE) ceramics were compared. In particular, the level of expression and the intra- and extra-cellular organization of fibronectin, a glycoprotein involved in cellular adhesion and migration during tissue repair, was analyzed. Fibroblasts cultured on zirconia showed a higher growth rate, and underwent necrosis at lower levels than cells on FE ceramic, whereas either materials did not stimulate apoptosis. Adhesion capacity of fibroblasts was evaluated measuring adherent cell nucleic acids with the fluorimetric CyQuant assay, and it was found significantly higher in cells cultured on zirconia than on FE ceramic. This finding may be explained by the higher and more precocious expression of the adhesion protein fibronectin observed by indirect immunofluorescence in fibroblasts on zirconia. Overall, the results suggest that zirconia, exerting low cytotoxicity and strongly inducing adhesion capacity, increases cellular growth rate of fibroblasts. All these features suggest that zirconia could represent a more suitable biomaterial than FE ceramic for prosthesis in dentistry.
Journal of Biomedical Materials Research Part A 01/2008; 86(4):959-68. · 2.83 Impact Factor
[show abstract][hide abstract] ABSTRACT: Human parathyroid hormone-related protein (hPTHrP), identified in patients with paraneoplastic hypercalcemia and expressed by different cell types during development and adult life, plays important roles in many human neoplasms. Immunohistochemical and RT-PCR analyses of hPTHrP and human parathyroid hormone receptor type 1 (PTHR-1) in primary medulloblastoma confirmed their expression in both classic and desmoplastic variants at RNA and protein levels. To evaluate the functional role of hPTHrP, DAOY and D283 medulloblastoma and U87MG glioma cells, expressing high levels of hPTHrP and PTHR-1, were treated with anti-sense oligonucleotides for hPTHrP. Anti-sense treatment produced in all cell lines a decrease of cell proliferation and clonogenic activity and an increase of apoptosis, while addition of exogenous hPTHrP (1-37) prevented these effects. Anti-sense induced the increase of Caspase-3, Fas (CD95) mRNAs and Bax/Bcl-2 mRNA ratio after 12 h of cell treatment. Exogenous hPTHrP (1-37) increased intracellular Ca(2+) concentration in DAOY cells as revealed by FURA. Anti-sense treated cells showed a significant decrease of steady-state levels of intracellular Ca(2+), which was reverted by addition of exogenous hPTHrP (1-37). This study indicates that hPTHrP and PTHR-1 are expressed in medulloblastoma and could promote tumor growth, protecting cells from apoptosis.