Targeting Gut Microbiome With Prebiotic in Patients With CKD: The TarGut-CKD Study.

Introduction: Disruption of gut microbiota underpins some of the metabolic alterations observed in chronic kidney disease (CKD). Methods: In a nonrandomized, open-label, 3-phase pilot trial, with repeated measures within each phase, we examined the efficacy of oligofructose-enriched inulin (p-inulin) in changing the gut microbiome and their metabolic products in 15 patients with CKD. The stability of microbiome and metabolome was studied during the pretreatment phase (8 weeks), a p-inulin treatment phase (12 weeks), and a post treatment phase (8 weeks) of the study. Results: Study participants completed 373 of the 420 expected study visits (88.8%). Adherence to p-inulin was 83.4%. 16S rRNA sequencing was performed in 368 stool samples. A total of 1085 stool, urine, and plasma samples were subjected to untargeted metabolomic studies. p-inulin administration altered the composition of the gut microbiota significantly, with an increase in abundance of Bifidobacterium and Anaerostipes. Intersubject variations in microbiome and metabolome were larger than intrasubject variation, indicating the stability of the gut microbiome within each phase of the study. Overall metabolite compositions assessed by beta diversity in urine and stool metabolic profiles were significantly different across study phases. Several specific metabolites in stool, urine, and plasma were significant at false discovery rate (FDR) ≤ 0.1 over phase. Specifically, there was significant enrichment in microbial metabolites derived from saccharolysis. Conclusion: Results from our study highlight the stability of the gut microbiome and the expansive effect of p-inulin on microbiome and host cometabolism in patients with CKD. Findings from this study will enable rigorous design of microbiome-based intervention trials.

Dietary Protein and Fiber Affect Gut Microbiome and Treg/Th17 Commitment in Chronic Kidney Disease Mice.

BACKGROUND: Patients with chronic kidney disease (CKD) have dysbiosis, dysmetabolism, and immune dysregulation. Gut microbiome plays an important role shaping the immune system which is an important modulator of CKD progression. METHODS: We compared the effect of a diet low in protein and high in fiber (LP-HF; n = 7) to that of diet rich in protein, but low in fiber (HP-LF; n = 7) on gut microbiome and T-cell commitment in male CKD (Alb/TGF-ß1) mice. The gut microbiomes of these mice were subjected to 16S rRNA taxonomic profiling at baseline, 6 weeks and 12 weeks of the study. RESULTS: The LP-HF diet was associated with an increase in Butyricicoccus pullicaecorum BT, a taxon whose functions include those closely related to butyric acid synthesis (Kendall's W statistic = 180 in analysis of microbiome composition). HP-LF diet was associated with increased abundance of two predominantly proteolytic bacterial strains related to Parabacteroides distasonis (W statistic = 173), Mucispirillum schaedleri, and Bacteroides dorei (W statistic = 192). Pathway analysis suggested that the LP-HF diet induced carbohydrate, lipid, and butyrate metabolism. As compared with HP-LF mice, LP-HF mice had 1.7-fold increase in CD4+Foxp3+Treg cells in spleen and 2.4-fold increase of these cells in peripheral blood. There was an 87% decrease in percentage of CD4+ Th17 + cells in spleen and an 85% decrease in peripheral blood, respectively, in LP-HF mice compared to the HP-LF mice. CONCLUSION: The LP-HF diet promotes the proliferation of saccharolytic bacteria and favors T-cell commitment toward Treg cells in a CKD mouse of model. Clinical significance of the finding needs to be further investigated.

Alterations of gut microbial pathways and virulence factors in hemodialysis patients.

Alterations in gut microbiota might contribute to uremic toxicity and immune dysregulation in patients with end-stage renal disease. Hemodialysis patients are prone to infection and higher mortality following sepsis. The virulence factors in the gut metagenome have not been well studied in hemodialysis patients, which could be employed by microorganisms to successfully thrive and flourish in their hosts. In this study, we performed shotgun metagenomics sequencing on fecal DNA collected from 16 control subjects and 24 hemodialysis patients. Our analysis shows that a number of microbial species, metabolic pathways, antibiotic resistance, and virulence factors were significantly altered in hemodialysis patients compared with controls. In particular, erythromycin resistance methylase, pyridoxamine 5-phosphate oxidase, and streptothricin-acetyl-transferase were significantly increased in hemodialysis patients. The findings in our study laid a valuable foundation to further elucidate the causative role of virulence factors in predisposing HD patients to infection and to develop treatment strategies to reduce the genetic capacities of antibiotic resistance and virulence factors in HD patients.

Leptin modulated microRNA-628-5p targets Jagged-1 and inhibits prostate cancer hallmarks.

MicroRNAs (miRNAs) are single-stranded non-coding RNA molecules that play a regulatory role in gene expression and cancer cell signaling. We previously identified miR-628-5p (miR-628) as a potential biomarker in serum samples from men with prostate cancer (PCa) (Srivastava et al. in Tumour Biol 35:4867-4873, 10.1007/s13277-014-1638-1, 2014). This study examined the detailed cellular phenotypes and pathways regulated by miR-628 in PCa cells. Since obesity is a significant risk factor for PCa, and there is a correlation between levels of the obesity-associated hormone leptin and PCa development, here we investigated the functional relationship between leptin and miR-628 regulation in PCa. We demonstrated that exposure to leptin downregulated the expression of miR-628 and increased cell proliferation/migration in PCa cells. We next studied the effects on cancer-related phenotypes in PCa cells after altering miR-628 expression levels. Enforced expression of miR-628 in PCa cells inhibited cell proliferation, reduced PCa cell survival/migration/invasion/spheroid formation, and decreased markers of cell stemness. Mechanistically, miR-628 binds with the JAG1-3'UTR and inhibits the expression of Jagged-1 (JAG1). JAG1 inhibition by miR-628 downregulated Notch signaling, decreased the expression of Snail/Slug, and modulated epithelial-mesenchymal transition and invasiveness in PC3 cells. Furthermore, expression of miR-628 in PCa cells increased sensitivity towards the drugs enzalutamide and docetaxel by induction of cell apoptosis. Collectively our data suggest that miR-628 is a key regulator of PCa carcinogenesis and is modulated by leptin, offering a novel therapeutic opportunity to inhibit the growth of advanced PCa.

MicroRNA-214 targets PTK6 to inhibit tumorigenic potential and increase drug sensitivity of prostate cancer cells.

Prostate cancer is the most commonly diagnosed cancer in men with African American men disproportionally suffering from the burden of this disease. Biomarkers that could discriminate indolent from aggressive and drug resistance disease are lacking. MicroRNAs are small non-coding RNAs that affect numerous physiological and pathological processes, including cancer development and have been suggested as biomarkers and therapeutic targets. In the present study, we investigated the role of miR-214 on prostate cancer cell survival/migration/invasion, cell cycle regulation, and apoptosis. miR-214 was differentially expressed between Caucasian and African American prostate cancer cells. Importantly, miR-214 overexpression in prostate cancer cells induced apoptosis, inhibiting cell proliferation and colony forming ability. miR-214 expression in prostate cancer cells also inhibited cell migration and 3D spheroid invasion. Mechanistically, miR-214 inhibited prostate cancer cell proliferation by targeting protein tyrosine kinase 6 (PTK6). Restoration of PTK6 expression attenuated the inhibitory effect of miR-214 on cell proliferation. Moreover, simultaneous inhibition of PTK6 by ibrutinib and miR-214 significantly reduced cell proliferation/survival. Our data indicates that miR-214 could act as a tumor suppressor in prostate cancer and could potentially be utilized as a biomarker and therapeutic target.

MicroRNA-212 negatively regulates starvation induced autophagy in prostate cancer cells by inhibiting SIRT1 and is a modulator of angiogenesis and cellular senescence.

Among a number of non-coding RNAs, role of microRNAs (miRNAs) in cancer cell proliferation, cancer initiation, development and metastasis have been extensively studied and miRNA based therapeutic approaches are being pursued. Prostate cancer (PCa) is a major health concern and several deregulated miRNAs have been described in PCa. miR-212 is differentially modulated in multiple cancers however its function remains elusive. In this study, we found that miR-212 is downregulated in PCa tissues when compared with benign adjacent regions (n = 40). Also, we observed reduced levels of circulatory miR-212 in serum from PCa patients (n = 40) when compared with healthy controls (n = 32). Elucidating the functional role of miR-212, we demonstrate that miR-212 negatively modulates starvation induced autophagy in PCa cells by targeting sirtuin 1 (SIRT1). Overexpression of miR-212 also leads to inhibition of angiogenesis and cellular senescence. In conclusion, our study indicates a functional role of miR-212 in PCa and suggests the development of miR-212 based therapies.

Detection of circulatory microRNAs in prostate cancer.

Prostate cancer (PCa) is one of the most common cancer worldwide and accounts for 14.4 % of all new cancer cases. The clinical outcome and management of PCa can be significantly improved by use of biomarker assays for early detection, prognosis and also for prediction and monitoring of treatment response. MiRNAs are short, endogenous, single-stranded RNA molecules that play important role in regulation of gene expression and can modulate a number of cellular processes. Discovery of miRNAs in circulation has not only facilitated understanding their role in various diseases but also paved new avenues for biomarker discovery due to their ease of access and stability. The fact that a minimally invasive test based on miRNAs profiles can distinguish the presence or absence of disease illustrates immense potential of these molecules as predictive biomarkers.In this chapter, we have summarized the presumed mechanisms of miRNA release into the circulation and systematically summarized the studies of circulatory miRNAs in PCa. Also, we have mainly focused on the methodology of identification of circulatory miRNAs from biofluids.

Circulatory miR-628-5p is downregulated in prostate cancer patients.

Prostate cancer (PCa) is a major health concern for men in the USA. Aberrant expression of microRNAs (miRNAs) has been associated with the pathogenesis of various cancers, including PCa. Circulatory forms of miRNAs have been detected in serum and hold promise as minimally invasive cancer biomarkers. This study aimed to identify potential circulatory miRNAs that can provide insights into new mechanisms for clinical diagnosis of PCa and can serve as potential biomarkers and/or therapeutic targets. Candidate serum miRNAs were detected by using PCR microarray in a learning set of six African American (AA) and six Caucasian American (CA) PCa patients. Discriminating performance of candidate miRNAs was validated by qRT-PCR in serum samples from 36 AA (24 PCa patients and 12 controls) and 36 CA (16 PCa patients and 20 controls). From the miRNA profiling experiments, three differentially expressed miRNAs (miR-25, miR-101, and miR-628-5p) were selected for future validation. In the validation set, there was an overall low expression of miR-25 (p < 0.01), miR-101 (p < 0.001), and miR-628-5p (p < 0.0001) in serum of PCa patients as compared with normal individuals. Subdivision on the basis of ethnicity showed that serum expression levels of miR-628-5p were significantly downregulated in both AA and CA PCa patients when compared with their respective controls. Our results demonstrate that the three miRNAs, particularly miR-628-5p, may be further developed as a biomarker, which can serve as novel noninvasive biomarker for PCa diagnosis and prognosis.

MicroRNA profiling in prostate cancer--the diagnostic potential of urinary miR-205 and miR-214.

Prostate cancer (PCa) is the most common type of cancer in men in the United States, which disproportionately affects African American descents. While metastasis is the most common cause of death among PCa patients, no specific markers have been assigned to severity and ethnic biasness of the disease. MicroRNAs represent a promising new class of biomarkers owing to their inherent stability and resilience. In the present study, we investigated potential miRNAs that can be used as biomarkers and/or therapeutic targets and can provide insight into the severity and ethnic biasness of PCa. PCR array was performed in FFPE PCa tissues (5 Caucasian American and 5 African American) and selected differentially expressed miRNAs were validated by qRT-PCR, in 40 (15 CA and 25 AA) paired PCa and adjacent normal tissues. Significantly deregulated miRNAs were also analyzed in urine samples to explore their potential as non-invasive biomarker for PCa. Out of 8 miRNAs selected for validation from PCR array data, miR-205 (p<0.0001), mir-214 (p<0.0001), miR-221(p<0.001) and miR-99b (p<0.0001) were significantly downregulated in PCa tissues. ROC curve shows that all four miRNAs successfully discriminated between PCa and adjacent normal tissues. MiR-99b showed significant down regulation (p<0.01) in AA PCa tissues as compared to CA PCa tissues and might be related to the aggressiveness associated with AA population. In urine, miR-205 (p<0.05) and miR-214 (p<0.05) were significantly downregulated in PCa patients and can discriminate PCa patients from healthy individuals with 89% sensitivity and 80% specificity. In conclusion, present study showed that miR-205 and miR-214 are downregulated in PCa and may serve as potential non-invasive molecular biomarker for PCa.

Potential biomarkers in gallbladder cancer: present status and future directions.

CONTEXT: Carcinoma of the gallbladder (GBC) is the most common biliary tree cancer in the world. Beside gallstones, no specific risk factors for GBC are currently established. Several published studies have identified various prognostic gene expression markers in GBC. OBJECTIVE: The present article reviewed published studies on gene expression biomarkers and gallbladder cancer susceptibility. METHODS: We searched the PubMed, Medline, and Embase databases using the search terms "Gallbladder", "cancer/carcinoma", "expression", "genes", "proteins", and "biomarker" updated until June 2012 and limited to English language papers. The online searching was accompanied by checking reference lists from the identified articles for potentially eligible original reports. RESULTS: Potential GBC biomarkers identified by different studies were summarized. CONCLUSION: To infer, the present article highlights a few potential biomarkers in GBC. However, none of the markers identified so far are effective as a routine screening test in GBC.

Comprehensive review of genetic association studies and meta-analyses on miRNA polymorphisms and cancer risk.

BACKGROUND: MicroRNAs (miRNAs) are small RNA molecules that regulate the expression of corresponding messenger RNAs (mRNAs). Variations in the level of expression of distinct miRNAs have been observed in the genesis, progression and prognosis of multiple human malignancies. The present study was aimed to investigate the association between four highly studied miRNA polymorphisms (mir-146a rs2910164, mir-196a2 rs11614913, mir-149 rs2292832 and mir-499 rs3746444) and cancer risk by using a two-sided meta-analytic approach. METHODS: An updated meta-analysis based on 53 independent case-control studies consisting of 27573 cancer cases and 34791 controls was performed. Odds ratio (OR) and 95% confidence interval (95% CI) were used to investigate the strength of the association. RESULTS: Overall, the pooled analysis showed that mir-196a2 rs11614913 was associated with a decreased cancer risk (OR = 0.846, P = 0.004, TT vs. CC) while other miRNA SNPs showed no association with overall cancer risk. Subgroup analyses based on type of cancer and ethnicity were also performed, and results indicated that there was a strong association between miR-146a rs2910164 and overall cancer risk in Caucasian population under recessive model (OR = 1.274, 95%CI = 1.096-1.481, P = 0.002). Stratified analysis by cancer type also associated mir-196a2 rs11614913 with lung and colorectal cancer at allelic and genotypic level. CONCLUSIONS: The present meta-analysis suggests an important role of mir-196a2 rs11614913 polymorphism with overall cancer risk especially in Asian population. Further studies with large sample size are needed to evaluate and confirm this association.

Survivin promoter -31G/C (rs9904341) polymorphism and cancer susceptibility: a meta-analysis.

This study aimed to perform a meta-analysis to assess the association of survivin -31 G/C promoter polymorphism and cancer risk. Thirteen case-control studies identified through PubMed and published between 2007 and 2011 with a total of 3329 cancer cases and 3979 controls were included in this meta-analysis. Odds ratio (OR) and 95% confidence interval (95% CI) were used to investigate the strength of the association. Overall, the pooled analysis showed that survivin -31C allele was associated with 1.27 fold increased risk of cancer compared with the -31G allele (95% CI = 1.091-1.479; random model). Subgroup analyses based on type of cancer and ethnicity were also performed, and results indicated that survivin -31G/C polymorphism was not associated with risk of gastric cancer [OR = 2.879; 95% CI = 0.553-15.004) for CC vs.GG] and esophageal cancer [OR = 1.352; 95% CI = 0.494-3.699) for CC vs.GG]. Stratification on the basis of ethnicity showed that the risk due to -31C allele was significant only in Asian population [OR = 1.894; 95% CI = 1.206-2.974 for CC vs.GG]. The present meta-analysis suggests an important role of survivin -31 G/C polymorphism with cancer risk especially in Asian population. However, further studies with larger sample size are required to draw more comprehensive conclusions and provide more precise evidence in individual cancers.

Candidate gene studies in gallbladder cancer: a systematic review and meta-analysis.

Gallbladder cancer (GBC) is the most frequent biliary tract malignancy. Wide variations in GBC incidence and familial and epidemiological data suggest involvement of a genetic component in its etiopathogenesis. A systematic review of genetic association studies in GBC was performed by applying a meta-analysis approach and systematically reviewing PubMed database using appropriate terms. Odds ratios (ORs) and 95% confidence intervals (CIs) were appropriately derived for each gene-disease association using fixed and random effect models. Meta-regression with population size and genotyping method was also performed. Study quality was assessed using a 10-point scoring system designed from published guidelines. Following a review of 44 published manuscripts and one unpublished report, 80 candidate gene variants and 173 polymorphisms were analyzed among 1046 cases and 2310 controls. Majority of studies were of intermediate quality. Four polymorphisms with >3 separate studies were included in the meta-analysis [OGG1 (rs1052133), TP53 (rs1042522), CYP1A1 (rs1048943) and GSTM1 null polymorphism]. The meta-analysis demonstrated no significant associations of any of the above polymorphisms with GBC susceptibility except TP53 (rs1042522) polymorphism. To conclude, existing candidate gene studies in GBC susceptibility have so far been insufficient to confirm any association. Future research should focus on a more comprehensive approach utilizing potential gene-gene, gene-environment interactions and high-risk haplotypes.

Gallbladder cancer predisposition: a multigenic approach to DNA-repair, apoptotic and inflammatory pathway genes.

Gallbladder cancer (GBC) is a multifactorial disease with complex interplay between multiple genetic variants. We performed Classification and Regression Tree Analysis (CART) and Grade of Membership (GoM) analysis to identify combinations of alleles among the DNA repair, inflammatory and apoptotic pathway genetic variants in modifying the risk for GBC. We analyzed 16 polymorphisms in 8 genes involved in DNA repair, apoptotic and inflammatory pathways to find out combinations of genetic variants contributing to GBC risk. The genes included in the study were XRCC1, OGG1, ERCC2, MSH2, CASP8, TLR2, TLR4 and PTGS2. Single locus analysis by logistic regression showed association of MSH2 IVS1+9G>C (rs2303426), ERCC2 Asp312Asn (rs1799793), OGG1 Ser326Cys (rs1052133), OGG1 IVS4-15C>G (rs2072668), CASP8 -652 6N ins/del (rs3834129), PTGS2 -1195G>A (rs689466), PTGS2 -765G>C (rs20417), TLR4 Ex4+936C>T (rs4986791) and TLR2 -196 to -174del polymorphisms with GBC risk. The CART analysis revealed OGG1 Ser326Cys, and OGG1 IVS4-15C>G polymorphisms as the best polymorphic signature for discriminating between cases and controls. In the GoM analysis, the data was categorized into six sets representing risk for GBC with respect to the investigated polymorphisms. Sets I, II and III described low intrinsic risk (controls) characterized by multiple protective alleles while sets IV, V and VI represented high intrinsic risk groups (GBC cases) characterized by the presence of multiple risk alleles. The CART and GoM analyses also showed the importance of PTGS2 -1195G>A polymorphism in susceptibility to GBC risk. In conclusion, the present multigenic approach can be used to define individual risk profiles for gallbladder cancer in North Indian population.

Organic anion transporter 1B1 (SLCO1B1) polymorphism and gallstone formation: High incidence of Exon4 CA genotype in female patients in North India.

AIM: Gallstone disease is an important cause of abdominal morbidity Organic anion transport protein 1B1 (OATP1B1) (encoded by SLCO1B1) is a major transporter protein for bile salt uptake in enterohepatic circulation of bile salts. Disturbance in this pathway can decrease relative concentration of bile salts in gallbladder and may lead to formation of gallstones. We investigated role of SLCO1B1 polymorphisms [(Exon4 C > A (Pro155Thr; rs11045819) and Ex6 + 40T > C (Val174Ala; rs4149056)] in conferring interindividual susceptibility to gallstone disease. METHODS: A total of 173 healthy controls and 226 gallstone patients (USG positive) were recruited. Genotyping was done by using standard polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: The observed control frequencies of both polymorphisms of SLCO1B1 gene [(Exon4 C > A (Pro155Thr; rs11045819) and Ex6 + 40T > C (Val174Ala; rs4149056)] were in agreement with Hardy-Weinberg equilibrium. The frequency CA genotype and A allele of Exon4 C > A polymorphism was higher in gallstones patients (12.4% and 6.2%) as compared to controls (5.2% and 2.6%) which was statistically significant [(P = 0.029; OR = 2.31; 95% CI = 1.1-5.0); (P = 0.034; OR = 2.22; 95% CI = 1.1-4.8)], respectively). However, distribution of genotypes and alleles of Ex6 + 40T > C polymorphism was almost similar between gallstone patients and controls. Haplotype analysis showed frequency of A,T haplotype consisting of was significantly higher in gallstone patients as compared to controls and was imposing risk for the disease (P = 0.036; OR = 2.34; 95% CI = 1.0-5.1). CONCLUSION: These results suggest that SLCO1B1 Exon4 C > A polymorphism confers increased risk for gallstone disease in North Indian population.

Circulating MicroRNA as Biomarkers: An Update in Prostate Cancer.

Prostate cancer (PCa) is the most common non-skin cancer among men. Currently available diagnostic tests for PCa are inadequate in terms of low specificity and poor sensitivity. microRNAs offer a hope to overcome these drawbacks by virtue of their cancer specific expression and high stability. They can readily be detected and quantified in frozen and as well as formalin-fixed paraffin-embedded tissues. Observation of circulating miRNA in serum/plasma samples and other body fluids holds a promise to quickly move from research and provide a biomolecule of clinical relevance and an improvement over presently available biomarkers. This review highlights the potential role of circulating miRNAs as molecular markers for cancer and as targets for therapeutic manipulation. Further, this review summarizes the current understanding of various circulating miRNA with respect to prostate cancer. To conclude, circulating miRNAs are an active area of current investigation and holds promise to serve a wide range of clinical applications and unwrap a new era in cancer diagnosis and therapeutics.

Role of ABCG8 D19H (rs11887534) variant in gallstone susceptibility in northern India.

BACKGROUND AND AIM: The excretion of cholesterol from the liver is regulated by the ATP-binding cassette transporter ABCG8. A common genetic polymorphism D19H of ABCG8 might be related to the genetic predisposition of gallstone disease, which is causatively related to supersaturation of cholesterol in bile. We aimed to examine the role of the ABCG8 D19H (rs11887534) polymorphism in susceptibility to gallstone disease in the northern Indian population. METHODS: The study included 220 confirmed gallstone patients and 230 controls. Genotyping for the ABCG8 D19H polymorphism was carried out using the PCR-RFLP method. RESULTS: We observed that the ABCG8 DH genotype frequency was significantly higher in gallstone patients (P = 0.038; odds ratio [OR] = 2.20; 95% confidence interval [CI] = 1.1-4.6). At allele level also, the ABCG8 variant allele conferred an increased risk for gallstone susceptibility (P = 0.043; OR = 2.12; 95% CI = 1.2-4.3). The risk as a result of ABCG8 D19H variation was more pronounced in female gallstone patients at genotype (P = 0.026; OR = 3.01, 95% CI = 1.1-7.9) as well as allele level (P = 0.030; OR = 2.85; 95% CI = 1.1-7.3). However, the molecular modeling results of the rs11887534 polymorphism showed that the overall configuration of both wild-type and polymorphic ABCG8 protein were similar, with negligible deviation at the site of polymorphism. CONCLUSION: Carriers of the DH genotype and H allele of the ABCG8 D19H polymorphism harbor a higher risk for gallstone susceptibility in the northern Indian population.

Effect of genetic variant (rs11887534) in ABCG8 gene in coronary artery disease and response to atorvastatin therapy.

BACKGROUND: ATP-binding cassette transporter ABCG8 plays an important role in excretion of cholesterol from liver. Common genetic polymorphisms in ABCG8 gene may genetically predispose an individual to coronary artery disease (CAD) along with response to atorvastatin therapy. Thus, we aimed to examine the role of ABCG8 D19H polymorphism (rs11887534) in susceptibility to CAD and its influence on atorvastatin response. METHODOLOGY: The study included 213 CAD patients and 220 controls. Genotyping of ABCG8 D19H polymorphism was done by PCR-RFLP. RESULTS: Our results showed that ABCG8 'H' allele was conferring significant risk for CAD in a dominant model (OR=2.54; p=0.014). This increased risk for CAD was more pronounced in males (OR=2.69; p=0.030). No correlation of ABCG8 genotypes with the risk factors (diabetes, hypertension and smoking) of CAD was observed. On atorvastatin treatment there was a significant decrease in the LDL-C levels (p=0.021). However, stepwise multiple regression analysis showed that this decease was not associated with ABCG8 genetic variant (p=0.845). Observed determinants of variation in interindividual response to atorvastatin therapy were pre-treatment LDL-C (p= 0.024) and TC (p=0.017). CONCLUSION: Although the genetic variant 19H of ABCG8 confers risk for CAD in North Indian population, it is not associated with interindividual response to atorvastatin therapy.

Caspase-8 polymorphisms and risk of gallbladder cancer in a northern Indian population.

Caspase-8 (CASP8) is a key controller of apoptosis, and its deregulation plays an important role in carcinogenesis. To evaluate the role of CASP8 polymorphisms in gallbladder cancer (GBC), we examined the risk associated with three single-nucleotide polymorphisms (SNPs) in a case-control study in North Indian population. Genotypes and haplotypes of the CASP8 polymorphisms (-652 6N ins/del; rs3834129, Ex13 + 51G > C; rs1045485 and IVS12-19 G > A; rs3769818) were determined for 230 GBC patients and 230 cancer-free controls randomly selected from the population. Odds ratio (OR) and 95% confidence interval (95% CI) were calculated in multivariate logistic regression analysis for the association of individual SNPs and haplotypes with GBC. Carriers for the "del" allele of rs3834129 SNP were associated with a 0.60-fold decreased risk for GBC (95% CI = 0.42-0.88; P(trend) = 0.005). In the combined analysis of the three CASP8 variants, we found that the individuals with the diplotypes carrying two copies of the common CASP8 del-G-G haplotype had 0.35-fold reduced risk (95% CI = 0.14-0.85) when compared with the diplotype containing 0-1 copy. The false-positive report probability (FPRP) approach advocated that these results were noteworthy (FPRP < 0.5). The molecular modeling results of rs1045485 polymorphism indicated that the overall configuration of both wild-type and polymorphic CASP8 protein were similar, with negligible deviation at the site of the polymorphism itself. In summary, low penetrance variants in CASP8 gene may alter the susceptibility toward GBC.

Polymorphisms in ERCC2, MSH2, and OGG1 DNA repair genes and gallbladder cancer risk in a population of Northern India.

BACKGROUND: Genetic variants of DNA repair enzymes may lead to genetic instability and contribute to gallbladder (GB) carcinogenesis. METHODS: A case-control study (230 GB carcinogenesis patients and 230 controls) was undertaken to evaluate whether genetic variations in 3 DNA repair genes ERCC2 (Asp312Asn [rs1799793] and Lys751Gln [rs13181]), MSH2 (-118T > C [rs2303425] and IVS1 + 9G>C [rs2303426]), and OGG1 (Ser326Cys [rs1052133] and 748-15C > G [rs2072668]) are associated with GB carcinogenesis risk in a North Indian population. RESULTS: The authors found that the ERCC2 Asp312Asn AA, MSH2 IVS1 + 9G > C CC, OGG1 Ser326Cys GG and CG + GG, and OGG1 748-15C > G GG and CG + GG genotypes were significantly associated with an increased risk of GB carcinogenesis (odds ratio [OR], 2.1, 1.8, 2.5, 1.8, 2.0, and 1.6, respectively). In contrast, ERCC2 Lys751Gln, and MSH2 -118T > C markers showed no significant associations with GB carcinogenesis risk, although because of the small sample size their effects cannot be ruled out. Female GB carcinogenesis patients with the OGG1 748-15C > G GG, OGG1 Ser326Cys GG, and ERCC2 Asp312Asn genotypes had a greater risk for developing the disease (OR, 3.6, 7.7, and 2.7, respectively). There was a significant interaction between MSH2 IVS1 + 9G > C and OGG1 748-15C > G polymorphisms (P = .001). Furthermore, individuals with > 6 variant alleles of the studied polymorphisms were at 4-fold increased risk for developing GB carcinogenesis. Classification and Regression Tree analysis revealed potential higher-order gene-gene interactions and categorized a few higher-risk subgroups for GB carcinogenesis. CONCLUSIONS: These results suggest that genetic variants in the DNA repair pathways may be involved in GB carcinogenesis etiology.