Fat burning capacity in a mixed macronutrient meal protocol does not reflect metabolic flexibility in women who are overweight or obese.

Introduction: Metabolic flexibility, the ability to switch from glucose to fat as a fuel source, is considered a marker of metabolic health. Higher fat oxidation is often associated with greater flexibility and insulin sensitivity, while lower fat oxidation is linked to metabolic inflexibility and insulin resistance. However, our study challenges the universal validity of this relationship, uncovering a more nuanced understanding of the complex interplay between fuel source switching and fat oxidation, especially in the presence of insulin resistance. Methods: In an 8-week controlled feeding intervention, overweight to obese women with insulin resistance (as defined by McAuley's index) were randomized to consume either a diet based on the Dietary Guidelines for Americans 2010 (DGA) or a 'Typical' American Diet (TAD), n = 22 each. Participants were given a high-fat mixed macronutrient challenge test (MMCT) (60% fat, 28% carbohydrates, and 12% protein) at weeks 0, 2, and 8. Plasma lipids, metabolome, and lipidome were measured at 0, 0.5, 3, and 6h postprandial (PP); substrate oxidation measures were also recorded at 0,1 3, and 6h PP. Metabolic flexibility was evaluated as the change in fat oxidation from fasting to PP. Mixed model and multivariate analyses were used to evaluate the effect of diet on these outcomes, and to identify variables of interest to metabolic flexibility. Results: Intervention diets (DGA and TAD) did not differentially affect substrate oxidation or metabolic flexibility, and equivalence tests indicated that groups could be combined for subsequent analyses. Participants were classified into three groups based on the % of consumed MMCT fat was oxidized in the 6h post meal period at weeks 0, 2 and 8. Low fat burners (LB, n = 6, burned <30% of fat in MMCT) and high fat burners (HB, n = 7, burned > 40% of fat in MMCT) at all weeks. Compared to LB, HB group had higher fat mass, total mass, lean mass, BMI, lower HDLc and lower RER (p < 0.05), but not different % body fat or % lean mass. During week 0, at 1h PP, LB had an increase in % fat oxidation change from 0h compared to HB (p<0.05), suggesting higher metabolic flexibility. This difference disappeared later in the PP phase, and we did not detect this beyond week 0. Partial least squares discriminant analysis (PLSDA (regular and repeated measures (sPLSDA)) models identified that LB group, in the late PP phase, was associated with higher rates of disappearance of acylcarnitines (AC) and lysophosphatidylcholines (LPC) from plasma (Q2: 0.20, R2X: 0.177, R2Y: 0.716). Conclusion: In women with insulin resistance, a high fat burning capacity does not imply high metabolic flexibility, and not all women with insulin resistance are metabolically inflexible. LPCs and ACs are promising biomarkers of metabolic flexibility.

Gestational long-term hypoxia induces metabolomic reprogramming and phenotypic transformations in fetal sheep pulmonary arteries.

Gestational long-term hypoxia increases the risk of myriad diseases in infants including persistent pulmonary hypertension. Similar to humans, fetal lamb lung development is susceptible to long-term intrauterine hypoxia, with structural and functional changes associated with the development of pulmonary hypertension including pulmonary arterial medial wall thickening and dysregulation of arterial reactivity, which culminates in decreased right ventricular output. To further explore the mechanisms associated with hypoxia-induced aberrations in the fetal sheep lung, we examined the premise that metabolomic changes and functional phenotypic transformations occur due to intrauterine, long-term hypoxia. To address this, we performed electron microscopy, Western immunoblotting, calcium imaging, and metabolomic analyses on pulmonary arteries isolated from near-term fetal lambs that had been exposed to low- or high-altitude (3,801 m) hypoxia for the latter 110+ days of gestation. Our results demonstrate that the sarcoplasmic reticulum was swollen with high luminal width and distances to the plasma membrane in the hypoxic group. Hypoxic animals were presented with higher endoplasmic reticulum stress and suppressed calcium storage. Metabolically, hypoxia was associated with lower levels of multiple omega-3 polyunsaturated fatty acids and derived lipid mediators (e.g., eicosapentaenoic acid, docosahexaenoic acid, α-linolenic acid, 5-hydroxyeicosapentaenoic acid (5-HEPE), 12-HEPE, 15-HEPE, prostaglandin E3, and 19(20)-epoxy docosapentaenoic acid) and higher levels of some omega-6 metabolites (P < 0.02) including 15-keto prostaglandin E2 and linoleoylglycerol. Collectively, the results reveal broad evidence for long-term hypoxia-induced metabolic reprogramming and phenotypic transformations in the pulmonary arteries of fetal sheep, conditions that likely contribute to the development of persistent pulmonary hypertension.

Luteal Lipids Regulate Progesterone Production and May Modulate Immune Cell Function During the Estrous Cycle and Pregnancy.

Although the corpus luteum (CL) contains high concentrations of lipid in the form of steroid hormone precursors and prostaglandins, little is known about the abundance or function of other luteal lipid mediators. To address this, 79 lipid mediators were measured in bovine CL, using ultra performance liquid chromatography-tandem mass spectrometry. CL from estrous cycle days 4, 11, and 18 were compared and, separately, CL from days 18 of the estrous cycle and pregnancy were compared. Twenty-three lipids increased as the estrous cycle progressed (P < 0.05), with nine increasing between days 4 and 11 and fourteen increasing between days 4 and 18. Overall, this indicated a general upregulation of lipid mediator synthesis as the estrous cycle progressed, including increases in oxylipins and endocannabinoids. Only 15-KETE was less abundant in the CL of early pregnancy (P < 0.05), with a tendency (P < 0.10) for four others to be less abundant. Notably, 15-KETE also increased between estrous cycle days 4 and 18. Ingenuity Pathway Analysis (IPA, Qiagen) indicated that functions associated with differentially abundant lipids during the estrous cycle included leukocyte activation, cell migration, and cell proliferation. To investigate changes in CL during maternal recognition of pregnancy, this lipid dataset was integrated with a published dataset from mRNA profiling during maternal recognition of pregnancy. This analysis indicated that lipids and mRNA that changed during maternal recognition of pregnancy may regulate some of the same functions, including immune cell chemotaxis and cell-cell communication. To assess effects of these lipid mediators, luteal cells were cultured with 5-KETE or 15-KETE. One ng/mL 5-KETE reduced luteal progesterone on day 1 of culture, only in the absence of luteinizing hormone (LH), while 1 ng/mL 15-KETE induced progesterone only in the presence of LH (10 ng/mL). On day 7 of culture, 0.1 ng/mL 15-KETE reduced prostaglandin (PG)F2A-induced inhibition of LH-stimulated progesterone production, while 1 ng/mL 15-KETE did not have this effect. Overall, these data suggest a role for lipid mediators during luteal development and early pregnancy, as regulators of steroidogenesis, immune cell activation and function, intracellular signaling, and cell survival and death.

Oral ibuprofen differentially affects plasma and sweat lipid mediator profiles in healthy adult males.

Sweat contains a variety of lipid mediators, but whether they originate from the plasma filtrate or from the cutaneous sweat glandular tissues themselves is unknown. To explore this knowledge gap, we collected plasma and sweat from healthy men (n = 9) immediately before and 0.5, 2 and 4 h after oral administration of 400 mg ibuprofen. Of the over 100 lipid mediators assayed by liquid chromatography-tandem mass spectrometry, ∼45 were detected in both plasma and sweat, and 36 were common to both matrices. However, baseline concentrations in each matrix were not correlated and metabolite relative abundances between matrices differed. Oral ibuprofen administration altered sweat lipid mediators, reducing prostaglandin E2, linoleoylethanolamide, and oleoylethanolamide, while increasing 11-hydroxyeicosatetraenoic acid, and causing transient changes in 9-nitrooleate, N-arachidonylglycine and 20-hydroxyeicosatetraenoic acid. Meanwhile, plasma N-acylethanolamide concentrations increased with ibuprofen administration. These results suggest that sweat and plasma differentially reflect biochemical changes due to oral ibuprofen administration, and that plasma is unlikely to be the predominant source of the sweat lipid mediator profile.

DHA-derived oxylipins, neuroprostanes and protectins, differentially and dose-dependently modulate the inflammatory response in human macrophages: Putative mechanisms through PPAR activation.

Whereas the anti-inflammatory properties and mechanisms of action of long chain ω3 PUFAs have been abundantly investigated, research gaps remain regarding the respective contribution and mechanisms of action of their oxygenated metabolites collectively known as oxylipins. We conducted a dose-dependent and comparative study in human primary macrophages aiming to compare the anti-inflammatory activity of two types of DHA-derived oxylipins including the well-described protectins (NPD1 and PDX), formed through lipoxygenase pathway and the neuroprostanes (14-A4t- and 4-F4t-NeuroP) formed through free-radical mediated oxygenation and expected to be new anti-inflammatory mediators. Considering the potential ability of these DHA-derived oxylipins to bind PPARs and knowing the central role of these transcription factors in the regulation of macrophage inflammatory response, we performed transactivation assays to compare the ability of protectins and neuroprostanes to activate PPARs. All molecules significantly reduced mRNA levels of cytokines such as IL-6 and TNF-α, however not at the same doses. NPD1 showed the most effect at 0.1µM (-14.9%, p<0.05 for IL-6 and -26.7%, p<0.05 for TNF-α) while the three other molecules had greater effects at 10µM, with the strongest result due to the cyclopentenone neuroprostane, 14-A4t-NeuroP (-49.8%, p<0.001 and -40.8%, p<0.001, respectively). Part of the anti-inflammatory properties of the DHA-derived oxylipins investigated could be linked to their activation of PPARs. Indeed, all tested oxylipins significantly activated PPARγ, with 14-A4t-NeuroP leading to the strongest activation, and NPD1 and PDX also activated PPARα. In conclusion, our results show that neuroprostanes and more especially cyclopentenone neuroprostanes have potent anti-inflammatory activities similar or even more pronounced than protectins supporting that neuroprostanes should be considered as important contributors to the anti-inflammatory effects of DHA.

BRCA1 promoter methylation in peripheral blood DNA was identified in sporadic breast cancer and controls.

OBJECTIVE: Epigenetics, particularly DNA methylation, has recently been shown to be important in breast cancer initiation. We investigated the clinical and prognostic importance of whole blood breast cancer early onset gene 1 (BRCA1) DNA methylation in sporadic breast cancer. METHODS: Genomic DNA was extracted from the peripheral blood cells (PBCs) of 902 breast cancer patients at diagnosis, with no BRCA1 mutation, and 990 control women. DNA methylation was measured by quantitative analysis of methylated alleles (QAMA) to estimate the extent of methylation of 2 CpG sites in the promoter region of BRCA1 oncosuppressor. RESULTS: BRCA1 promoter methylation rate in PBCs was 47.1% with a 95% confidence interval [46.1; 48.1] in breast cancer patients, and 45.9% with a 95% confidence interval [45.0; 46.8] in controls. We found a trend toward BRCA1 promoter hypermethylation in PBCs of sporadic breast cancer patients compared with controls. Association between methylation and clinicopathological features was evaluated using statistical tests. BRCA1 promoter methylation in PBCs increased significantly in breast cancer patients compared with controls, for age over 70 years (p=0.022), in post-menopausal status (p=0.013), for a body mass index (BMI) <20 (p=0.0095) or a waist-to-hip ratio (WHR) ≤76.8 (p=0.0027). We also found an association of increased BRCA1 promoter methylation in PBCs with ACA/ACA genotype for the SNP Thr594Thr in ESR (estrogen receptor gene), known to be associated with breast cancer risk (p=0.092), reflecting the reduced presence of this genotype in this breast cancer case-control study. CONCLUSION: Analysis of site-specific DNA methylation in PBCs by QAMA provides quantitative DNA methylation values that may serve as important prognostic indicators.

Can soy phytoestrogens decrease DNA methylation in BRCA1 and BRCA2 oncosuppressor genes in breast cancer?

Although soy phytoestrogens have been postulated to exert a protective effect against breast cancer, the attendant mechanisms, in particular epigenetics underpinnings, have remained elusive. We investigated the putative effects on DNA methylation by two naturally occurring isoflavones, genistein and daidzein, in a study of the BRCA1 and BRCA2 oncosuppressor genes in breast cancer cell lines (MCF-7, MDA-MB 231, and MCF10a). A demethylant agent, the 5-azacytidine, and a methylant, the budesonide, were used as treatment controls. DNA methylation of BRCA1 and BRCA2 was investigated with methylated DNA immunoprecipitation coupled with PCR. In parallel, protein expression was determined by Western blot, immunohistochemistry, and confocal microscopy. Our results suggest that treatment with 18.5 µM Genistein or 78.5 µM Daidzein might reverse DNA hypermethylation and restore the expression of the oncosuppressor genes BRCA1 and BRCA2. 5-Azacitydine also enhanced the reexpression of these genes while budesonide had an opposite effect. To the best of our knowledge, these observations, while requiring replication, provide new evidence on potential epigenetic mechanisms by which genistein and daidzein might contribute to regulation of the BRCA1 and BRCA2. Future studies are warranted on whether the demethylating effect of genistein and daidzein is global or focused on select candidate genes.

Epigenetic modulation of BRCA1 and BRCA2 gene expression by equol in breast cancer cell lines.

S-Equol is a metabolite resulting from the conversion of daidzein, a soya phyto-oestrogen, by the gut microflora. The potential protective effects of equol in breast cancer are still under debate. Consequently, we investigated the effects of equol on DNA methylation of breast cancer susceptibility genes (BRCA1 and BRCA2) and oncosuppressors in breast cancer cell lines (MDA-MB-231 and MCF-7) and in a dystrophic breast cell line (MCF-10a) following exposure to S-equol (2 µm) for 3 weeks. We demonstrated by quantitative analysis of methylated alleles a significant decrease in the methylation of the cytosine phosphate guanine (CpG) islands in the promoters of BRCA1 and BRCA2 after the S-equol treatment in MCF-7 and MDA-MB-231 cells and a trend in MCF-10a cells. We also showed that S-equol increases BRCA1 and BRCA2 protein expression in the nuclei and the cytoplasm in MCF-7, MDA-MB-231 and MCF-10a cell lines by immunohistochemistry. The increase in BRCA1 and BRCA2 proteins was also found after Western blotting in the studied cell lines. In summary, we demonstrated the demethylating effect of S-equol on the CpG islands inside the promoters of BRCA1 and BRCA2 genes, resulting in an increase in the level of expressed oncosuppressors in breast cancer cell lines.

DNA methylation and soy phytoestrogens: quantitative study in DU-145 and PC-3 human prostate cancer cell lines.

AIM: DNA hypermethylation is an epigenetic mechanism which induces silencing of tumor-suppressor genes in prostate cancer. Many studies have reported that specific components of food plants like soy phytoestrogens may have protective effects against prostate carcinogenesis or progression. Genistein and daidzein, the major phytoestrogens, have been reported to have the ability to reverse DNA hypermethylation in cancer cell lines. The aim of this study was to investigate the potential demethylating effects of these two soy compounds on BRCA1, GSTP1, EPHB2 and BRCA2 promoter genes. METHODS & MATERIALS: Prostate cell lines DU-145 and PC-3 were treated with genistein 40 µM, daidzein 110 µM, budesonide (methylating agent) 2 µM and 5-azacytidine (demethylating agent) 2 µM. In these two human prostate cancer cell lines we performed methylation quantification by using Methyl Profiler DNA methylation analysis. This technique is based on a methylation-specific digestion followed by quantitative PCR. We analyzed the corresponding protein expression by western blotting. RESULTS: Soy phytoestrogens induced a demethylation of all promoter regions studied except for BRCA2, which is not methylated in control cell lines. An increase in their protein expression was also demonstrated by western blot analysis and corroborated the potential demethylating effect of soy phytoestrogens. CONCLUSION: This study showed that the soy phytoestrogens, genistein and daidzein, induce a decrease of methylation of BRCA1, GSTP1 and EPHB2 promoters. Therefore, soy phytoestrogens may have a protective effect on prostate cancer. However, more studies are needed in order to understand the mechanism by which genistein and daidzein have an inhibiting action on DNA methylation.

miRNAs differentially expressed in prostate cancer cell lines after soy treatment.

BACKGROUND: MicroRNAs (miRNAs) are small non-coding RNAs that have aberrant expression in prostate cancer tissues. miRNAs are involved in the initiation and progression of cancer, and several miRNAs have been characterized as tumor suppressors or oncogenes. It has been shown that some miRNAs can be directly regulated from their own promoters by epigenetic alterations in cancer cells. Moreover, phytoestrogens are known to have epigenetic action on gene transcription. Hence, we conducted here an examination of the miRNA expression profile in human prostate cancer cell lines after soy phytoestrogen treatment. MATERIALS AND METHODS: The comparative miRNA expression profiles of prostate cell lines (PC-3, DU145, LNCaP) after a 48-h treatment of 40 µM genistein, 110 µM daidzein, or 2 µM 5-azacytidine (5-AZA, a demethylating agent) were conducted with a Taqman low-density array. RESULTS: We found that out of 377 miRNAs tested, 180, 170 and 150 miRNAs were amplified with 2% of variation in the triplicate in PC-3, DU145 and LNCap cells, respectively, and only 5 miRNAs for PC-3 and DU145 cells and 4 miRNAs for LNCap exhibited a significant change in their expression. Treatment with genistein or daidzein had similar effects on miRNA regulation to those of 5-AZA treatment. CONCLUSION: This work demonstrated a new role of isoflavones on the regulation of miRNAs in prostate cancer.

Peripheral blood DNA methylation detected in the BRCA1 or BRCA2 promoter for sporadic ovarian cancer patients and controls.

BACKGROUND: Ovarian cancer is located at the fifth rank of female cancers. Different risk factors including genetic factors with BRCA1 and BRCA2 genes played an important role in the etiology of the ovarian cancer. In most of sporadic ovarian cancer, variation in the expression of BRCA1 and BRCA2 genes was observed and it could be a consequence of epigenetic modifications. This work aimed to study methylation at CpG islands within the promoter of the BRCA1 and BRCA2 genes in sporadic ovarian cancers. METHODS: For this, we conducted a case-control study consisted of 51 ovarian cancer cases with no BRCA mutation and 349 healthy women. All participants came from the Auvergne region in France. Genomic DNA was extracted from peripheral blood cells (PBCs) and we used the Quantitative Analysis of Methylated Alleles (QAMA) to estimate the per cent of methylation in the BRCA1 and BRCA2 promoters. RESULTS: BRCA1 methylation is significantly decreased in ovarian cancer by comparison with the control group. The comparison between the two different populations did not show any significant difference regarding BRCA2 methylation but exhibited a trend in the decrease of BRCA2 promoter methylation in peripheral blood DNA of sporadic ovarian cancer. CONCLUSIONS: These results may have implications in better understanding the underlying epigenetic mechanisms in BRCA1 and BRCA2 oncosuppressors in sporadic ovarian cancer.

Soy phytoestrogens modify DNA methylation of GSTP1, RASSF1A, EPH2 and BRCA1 promoter in prostate cancer cells.

BACKGROUND: The aim of this study was to determine the effects of soy phytoestrogens on the methylation of promoter genes in prostate tumors. The incidence of prostate cancer in Asia is thirty percent lower than in Western countries. Since soy phytoestrogens represent a large portion of the Asian diet, evidence suggests their protective effect against prostate cancer. MATERIALS AND METHODS: In three human prostate cancer cell lines, methylation-specific-PCR was used to determine the effect of soy isoflavones (genistein and daidzein), compared to known demethylating agent 5-azacytidine as control in the promoter regions of glutathione S-transferase P1 (GSTP1), Ras association domain family 1 (RASSF1A), ephrin B2 (EPHB2) and breast cancer 1 (BRCA1) genes. In parallel, immunohistochemistry was used to assess the effects of genistein, daidzein and 5-azacytidine treatment on the corresponding protein expression. RESULTS: All studied promoters, with the exception of that for BRCA1, were strongly methylated without treatment. After treatment by phytoestrogens, demethylation of GSTP1 and EPHB2 promoter regions was observed and an increase in their protein expression was demonstrated by immunohistochemistry. CONCLUSION: Epigenetic modifications of DNA, such as the promoter CpG island demethylation of tumor suppressor genes, might be related to the protective effect of soy on prostate cancer.

Gene expression profiling of breast cancer cell lines in response to soy isoflavones using a pangenomic microarray approach.

Although the rate of breast cancer differs between women in Asian and Western countries, molecular genetics/genomics basis of this epidemiological observation remains elusive. Moreover, the intake of phytoestrogens is associated with a lower incidence of breast cancer. Genistein and daidzein are the primary soy isoflavones with a chemical structure similar to estrogens. Conceivably, the actions of phytoestrogens on gene expression signatures might mediate their postulated effects on breast cancer pathogenesis. The present study evaluated the transcriptional responsiveness of breast cancer cells to soy phytoestrogens using a whole-genome microarray-based approach. Human breast cancer cell lines and a fibrocystic breast cell line were treated with genistein or daidzein. We identified 278 and 334 differentially expressed genes after genistein or daidzein treatment, respectively, in estrogen-positive (MCF-7) and estrogen-negative (MDA-MB-231, MCF-10a) cells. Hierarchical clustering of this finding revealed a significant modulation, respectively, of 246 or 169 genes after genistein or daidzein exposures. Importantly, the molecular pathways for the differentially expressed genes included those that relate to cell communication, biodegradation of xenobiotics, lipid metabolism, signal transduction, and cell growth/death. These molecular observations collectively contribute to a growing knowledgebase on the putative mechanism(s) of action of phytoestrogens in breast cancer pathogenesis and chemoprevention.

Phytoestrogens regulate the expression of genes involved in different biological processes in BRCA2 knocked down MCF-7, MDA-MB-231 and MCF-10a cell lines.

Breast cancer is a public health problem in the Western countries. Several studies have shown that BRCA2, like BRCA1 oncosuppressors, are strongly involved in hereditary and sporadic mammary carcinogenesis. It has also been suggested that soy has a protective effect against breast cancer in Asia and, more particularly, phytoestrogens such as daidzein and genistein. Thus, phytoestrogens may have an impact on the expression of BRCA2 gene, and there is a possible link between BRCA2 and genes acting around the BRCA2. To focus on these processes, we set up the BRCA2 specific knockdown by RNA interference in two breast tumor cell lines (MCF-7 and MDA-MB-231) and also in a non-tumorigenic breast cell line (MCF-10a). After inhibition of BRCA2 expression, cells were maintained in different conditions and treated with either daidzein or genistein or left untreated. Microarray analysis of mRNAs isolated from the BRCA2 knocked down MCF-7, MDA-MB-231, and MCF-10a cell lines after being treated with phytoestrogens showed 35 differentially expressed genes between positive-ERbeta cells and negative-ERbeta cells. After genistein or daidzein treatments, BRCA1 was found to be up-regulated when knocked down with BRCA2-siRNA MCF-7 and BRCA2 was found to be up-regulated when knocked down with BRCA2-siRNA MDA-MB 231 cells. In MCF-10a, we observed a significant decrease in BAX and BCL2 expressions with a greater effect of daidzein. We also found an increase in BRIP expression between genistein and daidzein treatment knocked down with BRCA2-siRNA MCF-7 and MDA-MB-231 cell lines.

Immunohistochemical staining of mucin 1 in prostate tissues.

UNLABELLED: Prostate cancer is a major public health problem in the world. Molecular studies are necessary for the development of prognostic markers in prostate cancer. There is a great interest in mucin studies in treatment development of human malignancies, including prostate cancer. Nevertheless, their expressions in prostate cancer need further investigation. MATERIALS AND METHODS: Mucin 1 (MUC1) expression was examined in 100 prostate biopsies and were compared with prostate carcinoma cell lines (DU-145, PC-3, LNCaP) by immunohistochemistry. RESULTS: Biopsies were healthy, tumor, peritumor or presented an intraepithelial neoplasia. Staining of MUC1 was exihibited in PC-3 cells, was higher in DU-145, and was not expressed by LNCaP. Tumor sections presented more positive expression of MUC1 than non-tumor sections. CONCLUSION: MUC1 expression is correlated with the histological degree of malignancy.

Genetic polymorphisms in CYP1A1, CYP1B1, COMT, GSTP1 and NAT2 genes and association with bladder cancer risk in a French cohort.

UNLABELLED: Tobacco smoking and environmental exposures are the main known risk factors for bladder cancer (BC) via exposure to chemical carcinogens. Genetic differences in the metabolism of chemicals have been suggested to be associated with individual susceptibility to BC. Polymorphisms in genes coding to metabolising enzymes, resulting in variation of carcinogen detoxification efficiency, may therefore change the response of individuals to chemical carcinogens and be associated with an increased BC risk. PATIENTS AND METHODS: The aim of the study was to investigate the association between functional polymorphisms in CYP1A1, CYP1B1, COMT, GSTP1 and NAT2 genes and BC risk, through a hospital-based case-control study. The genotyping of 11 Single Nucleotide Polymorphisms (SNPs) was carried out on DNA of 51 bladder cancer male patients and 45 male controls. The technique of MGB (Minor Groove Binder) probes that utilize allelic discrimination with the Taqman(R) method was used. RESULTS: Individuals with NAT2 slow acetylator genotypes had a significant increase in risk of BC compared to individuals with NAT2 rapid acetylators (OR adjusted for smoking status=2.70; 95% CI, 1.10-6.61). GSTP1 Ile(105)Val variants (deletion of one - Ile/Val- and two -Val/Val-, null genotype- copies) showed a marginal increased risk of BC with OR adjusted for smoking status of 2.27 (95% CI, 0.97-5.31) compared to individuals carrying wild-type genotype (Ile/Ile). No statistically significant effects on BC risk with CYP1A1, CYP11B1 and COMT genotypes were observed. CONCLUSION: The results are consistent with previous literature among Caucasian populations.

DNA repair gene ERCC2, XPC, XRCC1, XRCC3 polymorphisms and associations with bladder cancer risk in a French cohort.

In polygenic diseases, association studies look for genetic variation such as polymorphisms in low penetrance genes, i.e. genes in interaction with environmental factors. DNA repair systems that protect the genome from deleterious endogenous and exogenous damage have been shown to significantly reduce activity. In particular, enzymes of the nucleotide excision repair pathway are suspected to be implicated in cancer. In this study bladder cancer which is viewed as a polygenic disease was investigated. The functional polymorphisms of four DNA repair genes, excision repair cross-complementing group 2 (ERCC2), Xeroderma Pigmentosum group C (XPC), and Xray repair cross-complementing groups 1 and 3 (XRCC1 and XRCC3) were analyzed. The studied population included 51 bladder cancer cases and 45 controls. The genotyping of six SNP (single nucleotide polymorphism) was carried out on these populations with the MGB (Minor Groove Binder) probe technique which uses allelic discrimination with the Taqman method. The Gln allele of the XPC 939 polymorphism was found to be associated with an increase in bladder cancer risk.

DNA repair gene ERCC2 polymorphisms and associations with breast and ovarian cancer risk.

Breast and ovarian cancers increased in the last decades. Except rare cases with a genetic predisposition and high penetrance, these pathologies are viewed as a polygenic disease. In this concept, association studies look for genetic variations such as polymorphisms in low penetrance genes, i.e. genes in interaction with environmental factors. DNA repair systems that protect the genome from deleterious endogenous and exogenous damages have been shown to have significantly reduced. In particular, enzymes of the nucleotide excision repair pathway are suspected to be implicated in cancer. In this study, 2 functional polymorphisms in a DNA repair gene ERCC2 were analyzed. The population included 911 breast cancer cases, 51 ovarian cancer cases and 1000 controls. The genotyping of 2 SNP (Single Nucleotide Polymorphism) was carried out on the population with the MGB (Minor Groove Binder) probe technique which consists of the use of the allelic discrimination with the Taqman method. This study enabled us to show an increase in risk of breast cancer with no oral contraceptive users and with women exhibiting a waist-to-hip ratio (WHR) > 0.85 for Asn homozygous for ERCC2 312.