[Show abstract][Hide abstract] ABSTRACT: The promotion and progression of carcinogenesis are susceptible to nutritional interventions aimed at counteracting cancer development. Lipid metabolism is essential in the onset and progression of tumours as well as for cancer cell survival. In the present study we tested the effects of diets enriched with natural compounds, such as olive oil and salmon oil, in mice that spontaneously develop intestinal polyps (Apc(Min/+) mice). For this purpose we evaluated polyp number and volume, intestinal mucosa proliferation/apoptosis, oestrogen receptors (ERs) expression, fatty acid synthase (FAS) and 3-hydroxy-3-methylglutaryl coenzyme A (HMGCoA) reductase gene expression and enzymatic activity. As compared to the standard diet, the salmon oil-enriched diet, containing a high percentage of omega-3 polyunsaturated fatty acids (omega-3 PUFAs) and, to a lesser extent, olive oil-enriched diet reduced polyp number and volume through a reduction of proliferation and a marked pro-apoptotic effect. These biological effects were mediated by an inhibition of FAS and HMGCoA reductase gene expression and activity and an increase of ERβ/ERα ratio. Our findings suggest that a proper dietary lifestyle could contribute to primary cancer prevention.
[Show abstract][Hide abstract] ABSTRACT: Alterations of lipid metabolism have been increasingly recognized as a hallmark of cancer cells. Cancer cells esterify fatty acids predominantly to phospholipids, an essential component of cell membranes. The main pathway along which proliferating cells gain lipids for membrane synthesis is the endogenous mevalonate pathway. Increased synthesis of mevalonate and mevalonate-derived isoprenoids supports increased cell proliferation through activating growth-regulatory proteins and oncoproteins and promoting DNA synthesis. The importance of a better knowledge of metabolic changes in lipogenic enzymes pathways, as well as of the role of each biochemical pathway in carcinogenesis, provides the rationale for in-depth study of the oncogenic signaling important for the initiation and progression of tumors. The dependence of tumor cells on a dysregulated lipid metabolism suggests that the proteins involved in this process may be excellent chemotherapeutic targets for cancer treatment. Here, we confirm the vital link between lipogenesis and cell proliferation, and our recent findings suggest that nutritional intervention is an effective and safe way to reduce cell proliferation in experimental models of carcinogenesis. The olive oil diet significantly reduces the protein activities of lipogenic enzymes associated with cell growth. The use of natural dietary components could potentially assist in the management of subjects with metabolic disorders-related tumors.
Current Medicinal Chemistry 03/2014; · 3.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Celiac disease is characterized by enhanced intestinal paracellular permeability due to alterations of function and expression of tight junction (TJ) proteins including ZO-1, Claudin-1 and Occludin. Polyamines are pivotal in the control of intestinal barrier function and are also involved in the regulation of intercellular junction proteins. Different probiotic strains may inhibit gliadin-induced toxic effects and the Lactobacillus rhamnosus GG (L.GG) is effective in the prevention and treatment of gastrointestinal diseases. Aims of the study were to establish in epithelial Caco-2 cells whether i) gliadin affects paracellular permeability and polyamine profile; ii) co-administration of viable L.GG, heat-killed L.GG (L.GG-HK) or its conditioned medium (L.GG-CM) preserves the intestinal epithelial barrier integrity. Additionally, the effects of L.GG on TJ protein expression were tested in presence or absence of polyamines.
Administration of gliadin (1 mg/ml) to Caco-2 cells for 6 h caused a significant alteration of paracellular permeability as demonstrated by the rapid decrease in transepithelial resistance with a concomitant zonulin release. These events were followed by a significant increase in lactulose paracellular transport and a slight lowering in ZO-1 and Occludin expression without affecting Claudin-1. Besides, the single and total polyamine content increased significantly. The co-administration of viable L.GG (108 CFU/ml), L.GG-HK and L.GG-CM with gliadin significantly restored barrier function as demonstrated by transepithelial resistance, lactulose flux and zonulin release. Viable L.GG and L.GG-HK, but not L.GG-CM, led to a significant reduction in the single and total polyamine levels. Additionally, only the co-administration of viable L.GG with gliadin significantly increased ZO-1, Claudin-1 and Occludin gene expression compared to control cells. When Caco-2 cells treated with viable L.GG and gliadin were deprived in the polyamine content by alpha-Difluoromethylornithine, the expression of TJ protein mRNAs was not significantly different from that in controls or cells treated with gliadin alone.
Gliadin modifies the intestinal paracellular permeability and significantly increases the polyamine content in Caco-2 cells. Concomitant administration of L.GG is able to counteract these effects. Interestingly, the presence of cellular polyamines is necessary for this probiotic to exert its capability in restoring paracellular permeability by affecting the expression of different TJ proteins.
[Show abstract][Hide abstract] ABSTRACT: To study, in intact male transgenic mice, the effects of three diets based on olive oil and olive oil diet supplemented with lovastatin and orlistat on hepatic lipogenic enzymes expression, considered markers of cell proliferation.
Forty Apc(Min/+) mice were randomly divided into 4 groups and fed for 10 wk: olive oil (OO) group, n = 10 animals received a diet with olive oil 12%; olive oil plus lovastatin (LOVA) group, n = 10 animals received the same diet with olive oil supplemented with lovastatin 5 mg/kg; olive oil plus orlistat (OR) group, n = 10 animals fed the diet with olive oil supplemented with orlistat 50 mg/kg and SD group, n = 10 animals fed a standard diet. The activity of lipogenic enzymes and their gene expression were evaluated by radiometric and real-time reverse transcription-polymerase chain reaction assay, respectively.
After 10 wk of dietary treatment, the body weight was no different among animal groups (21.3 ± 3.1 g for standard group, 22.1 ± 3.6 g for OO group, 22.0 ± 3.2 g for LOVA group and 20.7 ± 3.4 g for OR group, data expressed as mean ± SD), observing a generalized well-being in all animals. All the dietary managed treated groups presented significantly reduced hepatic levels of fatty acid synthase, farnesyl pyrophosphate synthase and 3-hydroxyl-3-methyl-glutaryl CoA reductase activity and gene expression when compared with the mice fed the standard diet. To evaluate cell proliferation in the liver of treated mice, the levels of cyclin E mRNA have been measured, demonstrating a significant reduction of cyclin E gene expression in all treated groups. Evidence of reduced hepatic cell proliferation was present overall in OO group mice.
We confirm the role of lipogenic enzymes as markers of cell proliferation, suggesting that appropriate dietary management alone or with drugs can be a feasible approach to counteract hepatic cell proliferation in mice.
World Journal of Gastroenterology 12/2013; 19(46):8671-7. · 2.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Aim: The aim of the present study was to evaluate the effects of a diet supplementation with either olive oil, or n-3 or n-6-polyunsaturatedFatty acids (PUFAs) on tumour development and gene expression for lipogenic enzymes in Apc(Min/+) mice.
In the control group, the mice received a standard diet, the OO group was fed on a diet with 12% olive oil, the OM-3 group with 12% salmon fish rich in n-3 PUFAs, the OM-6 group with 12% oenothera oil rich in n-6 PUFAs. Gene expression of lipogenic enzymes was evaluated by real-time reverse transcription polymerase chain reaction.
All mice in the treated groups presented a reduction in total intestinal polyp number and load, which was particularly marked in the OM-3 group. Treated mice showed an induction of low density lipoprotein receptor gene expression and a significant reduction of expression of lipogenic gene.
Our data provide new insights into the mechanism of cell growth inhibition and apoptotic regulation by dietary olive oil and PUFAs in Apc(Min/+) mice.
Anticancer research 09/2013; 33(9):3739-44. · 1.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background. Olive oil intake has been shown to induce beneficial effect on health. This study aimed to investigate the effects of olive oil polyphenol hydroxytyrosol (HT) on cell proliferation and its antioxidant and anti-inflammatory capacity in human hepatoma Hep3B and HepG2 cell lines. Materials and Methods. Cell growth after HT treatment was measured by 3-(4,5 di-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. Lipogenic enzyme activity was evaluated by radiochemical assay. Cell total antioxidant activity and cell interleukin-6 (IL-6) levels were measured by enyme linked immunosorbent assay (ELISA) methods. Results. HT caused an evident antiproliferative effect mediated by inhibition of lipogenic enzymes. Moreover, HT induced activation of the cell antioxidant system and reduced cellular IL-6 levels. Conclusion. Our findings provide insights into the mechanisms of action of HT in the context of inhibition of cancer cell proliferation and prevention of oxidative stress in human hepatoma cells. Our results also show a down-regulation of lipogenic enzymes involved in cell proliferation.
Anticancer research 12/2012; 32(12):5371-7. · 1.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Lipid metabolism is altered in subjects with liver steatosis. FAS is a key enzyme in de novo lipogenesis and both FAS gene expression and enzymatic activity are primarily regulated by metabolic signals in the liver. Lipoprotein lipase (LPL), the rate-limiting enzyme for the hydrolysis of core triglycerides, plays a pivotal role in lipid metabolism. This study aims to investigate if circulating levels of FAS and LPL could be clinically associated with liver steatosis. METHODS: In this work, we present data obtained from a subsample of 94 subjects with liver steatosis enrolled by NUTRIEPA study, a nutritional trial in subjects with liver steatosis. Serum levels of FAS protein and LPL activity were evaluated by ELISA test and by a fluorescent method, respectively. The diagnosis and the degree of liver steatosis were based on laboratory and ecographic measurements. Statistical methods included Kruskal-Wallis analysis of variance and Wilcoxon signed-rank test, where appropriate. The chi2 test has been performed to analyse categorical variables. RESULTS: The subjects with severe steatosis had significantly higher serum levels of FAS protein and LPL activity compared to subjects with mild and moderate liver steatosis. Moreover, a positive trend in serum levels of FAS expression from lower to higher degree of steatosis was also detected. CONCLUSIONS: We describe a relationship between human liver steatosis and elevated levels of circulating lipogenic enzymes. Increased serum levels of FAS expression and LPL activity could be considered a marker of severe liver steatosis.
Lipids in Health and Disease 10/2012; 11(1):145. · 2.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Lipoprotein lipase (LPL) is the crucial enzyme for intravascular catabolism of triglyceride-rich lipoproteins. Fatty acid synthase (FAS) is a key anabolic enzyme that catalyzes the terminal steps in the novo biosynthesis of 18:2n-6. The involvement of both LPL and FAS in tumor biology has been widely demonstrated in different studies and to verify whether there are regional differences in the expression of these enzymes in visceral adipose tissue from patients with colorectal cancer might be representative of events which sustain tumor growth. The objective of this study was to evaluate LPL and FAS activity and expression of their genes in adipose tissue adjacent to neoplasia and distant from it from patients operated for colorectal cancer. LPL enzymatic activity was evaluated by a fluorescent method and FAS activity by a radiometer assay. Reverse-transcription and real-time PCR were used to detect mRNA levels of two enzymes. Our findings show a significant reduction in both LPL and FAS gene expression and activity levels in adipose tissue adjacent to tumor lesion compared to those detected in paired tissue distant from neoplasia. These results underline the influence of tumor microenvironment on lipid metabolism in adipose tissue, demonstrating a tumor-induced impairment in the formation and lipid storing capacity of adipose tissue in patients with colorectal cancer.
[Show abstract][Hide abstract] ABSTRACT: The leptin receptor is involved in modulating leptin activity, acting as a carrier protein. A link between leptin or leptin receptor and cancer development has been proposed and here, the hypothesis that leptin and its receptor might be implicated in colorectal cancer (CRC) progression and invasion was investigated.
A total of 71 consecutive patients with CRC were enrolled in the study. Serum leptin and leptin receptor levels were evaluated by commercial ELISA kits.
The multinomial logistic regression model showed a positive association of leptin and leptin receptor with advanced tumor stages, which was significant for the leptin receptor in stage IV of disease.
High circulating levels of leptin receptor occur in patients with advanced stage of colon cancer, suggesting a role for leptin in cancer progression and aggressiveness.
Anticancer research 10/2011; 31(10):3381-3. · 1.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Fatty acid synthase is a common phenotype to various human cancers including those of prostate, colon, lung, endometrium, and stomach. Increased fatty acid synthase levels have been detected in serum from patients with breast and pancreatic cancer. In this study, serum levels of fatty acid synthase were measured in colorectal cancer patients at different stages of disease.
Consecutive 67 patients with colorectal cancer were enrolled in the study. Serum levels of fatty acid synthase were examined by ELISA test. The Kruskal-Wallis test and the χ (2) method for trend have been used to analyze data.
Serum fatty acid synthase levels of patients belonging to three groups of stage disease are statistically different. The patients with stage III and IV have significantly higher serum levels of fatty acid synthase than patients with stage I-II. There is a positive trend in serum fatty acid synthase levels from stage I-II to stage III and IV of disease.
Fatty acid synthase levels are associated with the stage of disease in patients with colorectal cancer.
Journal of Gastrointestinal Cancer 07/2011; 43(3):508-11.
[Show abstract][Hide abstract] ABSTRACT: Oleuropein (OL) and hydroxytyrosol (HT), the main olive oil polyphenols, possess anti-proliferative effects in vitro. Fatty acid synthase, a key anabolic enzyme of biosynthesis of fatty acids, plays an important role in colon carcinoma development. Our aim was to investigate whether gene expression of FAS, as well as its enzymatic activity, is regulated by HT and OL in two human colon cancer cell lines, as HT-29 and SW620. In addition, we investigated the effects of these polyphenols on growth and apoptosis in these cells. FAS gene expression and activity in treated HT-29 and SW620 cells were evaluated by real-time PCR and radiochemical assay, respectively. Cell growth and apoptosis, after polyphenols treatment, were measured by MTT test and flow cytometry, respectively. The inhibition of proliferation, detected after HT treatment, was mediated by an inhibition of FAS expression and its enzymatic activity in SW620 cells, while the anti-proliferative effect in HT-29 cells seems to be independent from FAS. OL exerted an anti-proliferative effect only on SW620 cells with a mechanism which excluded FAS. Olive oil polyphenols used were able to induce apoptosis in both cell lines studied. The increase of apoptosis in these cells was accompanied by the block of cell cycle in the S phase. This study demonstrates that HT and OL may induce anti-proliferative and pro-apoptotic effects only in certain human colorectal cancer cell types. These effects are FAS mediated only in SW620 cells after treatment with HT.
[Show abstract][Hide abstract] ABSTRACT: To investigate Glyoxalase I and fructosamine-3-kinase (FN3K) activity in red blood cells from patients with colorectal adenomas and cancer.
Thirty three consecutive subjects with one or more histologically confirmed colorectal adenomatous polyps, 16 colorectal cancer patients and a group of 11 control subjects with normal colonoscopy were included in the study. Glyoxalase I and FN3K activities were measured in red blood cells using a spectrophotometric and radiometric assay, respectively.
A significant reduction in both Glyoxalase I and FN3K activity was detected in patients with tumors compared to patients with adenomas and the controls. Erythrocyte Glyoxalase I activity in colorectal cancer was approximately 6 times lower than that detected in patients with adenoma (0.022 ± 0.01 mmol/min per milliliter vs 0.128 ± 0.19 mmol/min per milliliter of red blood cells, P = 0.003, Tukey's test). FN3K activity in red blood cells from patients with colon cancer was approximately 2 times lower than that detected in adenoma patients (19.55 ± 6.4 pmol/min per milliliter vs 38.6 ± 31.7 pmol/min per milliliter of red blood cells, P = 0.04, Tukey's test).
These findings suggest that deglycating enzymes may be involved in the malignant transformation of colon mucosa.
World Journal of Gastroenterology 01/2011; 17(3):329-33. · 2.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: n-3 and n-6 polyunsaturated fatty acids (PUFAs) are the two major classes of PUFAs encountered in the diet, and both classes of fatty acids are required for normal human health. Moreover, PUFAs have effects on diverse pathological processes impacting chronic disease, such as cardiovascular and immune disease, neurological disease, and cancer.
To investigate the effects of eicosapentaenoic acid (EPA) and arachidonic acid (ARA) on the proliferation and apoptosis of human hepatoma cell line HepG2 after exposure to increasing concentrations of EPA or ARA for 48 h. Moreover, in the same cells the gene expression of Fatty Acid Synthase (FAS) and 3-Hydroxy-3-Methyl-Glutaryl Coenzyme A Reductase (HMG-CoAR) was also investigated.
Cell growth and apoptosis were assayed by MTT and ELISA test, respectively after cell exposure to increasing concentrations of EPA and ARA. Reverse-transcription and real-time PCR was used to detect FAS and HMG-CoAR mRNA levels in treated cells.
Our findings show that EPA inhibits HepG2 cell growth in a dose-dependent manner, starting from 25 μM (P < 0.01, one-way ANOVA test and Dunnett's post test) and exerts a statistically significant pro-apoptotic effect already at 1 μM of EPA. Higher doses of ARA were need to obtain a statistically significant inhibition of cell proliferation and a pro-apoptotic effect in these cells (100 μM, P < 0.01, one-way ANOVA test and Dunnett's post test). Moreover, a down-regulation of FAS and HMG-CoAR gene expression was observed after EPA and ARA treatment in HepG2 cells, starting at 10 μM (P < 0.05, one-way ANOVA test and Dunnett's post test).
Our results demonstrate that EPA and ARA inhibit HepG2 cell proliferation and induce apoptosis. The down-regulation of FAS and HMG-CoAR gene expression by EPA and ARA might be one of the mechanisms for the anti-proliferative properties of PUFAs in an in vitro model of hepatocellular carcinoma.
Lipids in Health and Disease 01/2011; 10:10. · 2.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Fructosamine-3-Kinase (FN3K) is an enzyme phosphorilating fructoselysine (FL) residues on glycated proteins, resulting in the production of protein-bound FL-3-phosphate. The pathological role of the non-enzymatic modification of proteins by reducing sugars has become increasingly evident in various types of disorders, including the cancer. In this study, our aim was to study FN3K enzyme activity, as well as its mRNA in human colorectal cancer (CRC). Thirty consecutive CRC patients undergoing surgery of the colon were enrolled in the study. FN3K enzymatic activity and gene expression were analyzed using a radiometric assay and quantitative RT-PCR, respectively. FN3K is a functionally active enzyme in human colon tissue, without significant differences between normal mucosa and cancer. The mean level of FN3K mRNA was significantly lower in cancer than in the corresponding normal colorectal mucosa The colorectal tumors located on the left side showed lower levels of both enzymatic activity and mRNA FN3K than tumors located in the right side of colon. This paper is the first studying FN3K enzyme activity in human CRC, showing a significant relationship between enzymatic activity, its mRNA and tumor side.
[Show abstract][Hide abstract] ABSTRACT: Anandamide (AEA) is an endogenous agonist for cannabinoid receptor CB1-R and seems to be involved in the control of cancer growth. Polyamines are compounds that play an important role in cell proliferation and differentiation. Our aim was to investigate the effect of AEA on the polyamine levels (putrescine, spermidine and spermine) and cell growth of three human colon cancer cell lines, positive for CB1-R.
After AEA treatment of DLD-1, HT-29 and SW620 cells, polyamine analysis was performed by high-performance liquid chromatography (HPLC) and cell growth was measured by 3-(4,5 di-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. CB1 gene expression was determined using reverse transcription and polymerase chain reaction (RT-PCR).
AEA significantly reduced polyamine levels and cell proliferation dose-dependently when the tested cell lines were exposed for 24 h and 48 h. This inhibitory effect was mediated by CB1-R, since SR 1411716A, a selective CB-1 receptor antagonist, was able to entirely antagonize the effect of AEA. CB1-R mRNA levels were enhanced after AEA treatment in DLD-1 cells, whereas no induction was found in HT-29 and SW620 cells.
It appears that mechanisms by which AEA may affect growth of colon cancer cells involve a decrease in cell proliferation rate by reducing the polyamine levels.
Anticancer research 07/2010; 30(7):2583-9. · 1.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PUFAs are potent inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, an enzyme catalyzing the conversion of HMGCoA to mevalonate, the rate limiting step in cholesterol biosynthesis. Statins represent a class of drugs that are widely used to treat hypercholesterolemia for their ability to inhibit cholesterol biosynthesis and to up-regulate the synthesis of Low Density Lipoprotein (LDL) receptors in the liver. PUFAs mediate many, if not all, actions of statins and this could be one mechanism by which they lower cholesterol levels. The purpose of this study was to investigate whether combined treatment with Eicosapentaenoic acid (EPA) and lovastatin enhanced the regulatory effect on gene expression of HMGCoA reductase and LDL receptor in HepG2 cell line.
The combined treatment with EPA and lovastatin enhanced the regulatory effect on gene expression of HMGCoA reductase and LDL receptor in HepG2 cell line. Moreover, we detected a synergistic effect on the inhibition of cancer cell proliferation obtained by combination of EPA and Lovastatin.
The use of EPA, in combination with low doses of Lovastatin may have potential value in treatment of neoplastic diseases.
Lipids in Health and Disease 01/2010; 9:135. · 2.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Tumor cell proliferation and migration, as well as metastasis formation, can be affected by several neurotransmitters, which therefore seem to be involved in the most important aspects of the malignant phenotype. In particular, modified beta-adrenergic functions seem to be associated with proliferative alterations of numerous cancer cell lines. Pharmacological modulation of beta-adrenoceptors (beta-ARs) affects tumor cell growth in several experimental systems, and inhibition of metastasis formation by beta-AR antagonists in in vivo models has recently been reported. Initial epidemiological studies have provided evidence that beta-blockers can reduce cancer incidence, thus suggesting a possible role also in cancer prevention.
Colorectal mucosa and cancer tissue were obtained from 41 patients. Specimens were taken within 1 h after the surgical procedure and stored at -80 degrees C until assayed. The gene expression of beta(1)-, beta(2)- and beta(3)-ARs in cancer tissue and normal surrounding mucosa was measured by real-time PCRs.
Comparable levels of beta(1)- and beta(2)-AR mRNA were found to be expressed in normal mucosa and cancer tissues. A significant difference in beta(3)-AR mRNA levels between normal mucosa and cancer tissues was found, with beta(3)-AR mRNA expression being twice as high in cancer tissue than normal mucosa.
The results of the present study indicate that beta(3)-AR mRNA is upregulated in human colon cancer, thus suggesting the possible involvement of beta(3)-AR in malignant transformation in the human colon.
[Show abstract][Hide abstract] ABSTRACT: The major soy-derived isoflavones such as genistein has been demonstrated to possess anticarcinogenic activity in animal model systems. The present study was designed to investigate the effects of isoflavone genistein exposure at concentrations ranging from 0.01 to 50 muM on the LDL receptor and HMG-CoA reductase gene expression in the estrogen receptor positive DLD-1 human colon cancer cell line. LDL receptor and HMG-CoA reductase gene expressions were evaluated by reverse transcription followed by real-time PCR. Genistein induced an increase of LDL receptor gene expression and later decrease of HMG-CoA reductase mRNA expression in DLD-1 cells. These findings provide direct evidence on the role of genistein in regulating LDL receptor and HMG-CoA reductase gene expression in colon cancer.