Association of Wnt signaling pathway genetic variants in gallbladder cancer susceptibility and survival

Super-Enhancer Reprograming Driven by SOX9 and TCF7L2 Represents Transcription-Targeted Therapeutic Vulnerability for Treating Gallbladder Cancer

Gallbladder cancer (GBC) is a highly aggressive malignancy lacking clinically available targeted therapeutic agents. Super-enhancers (SEs) are crucial epigenetic cis-regulatory elements whose extensive reprogramming drives aberrant transcription in cancers. To study SE in GBC, the genomic distribution of H3K27ac is profiled in multiple GBC tissue and cell line samples to establish the SE landscape and its associated core regulatory circuitry (CRC). The biliary lineage factor SOX9 and Wnt pathway effector TCF7L2, two master transcription factor (TF) candidates identified by CRC analysis, are verified to co-occupy each other's SE region, forming a mutually autoregulatory loop to drive oncogenic SE reprogramming in a subset of GBC. The SOX9/TCF7L2 double-high GBC cells are highly dependent on the two TFs and enriched of SE-associated gene signatures related to stemness, ErbB and Wnt pathways. Patients with more such GBC cells exhibited significantly worse prognosis. Furthermore, SOX9/TCF7L2 double-high GBC preclinical models are found to be susceptible to SE-targeted CDK7 inhibition therapy in vitro and in vivo. Together, this study provides novel insights into the epigenetic mechanisms underlying the oncogenesis of a subset of GBCs with poorer prognosis and illustrates promising prognostic stratification and therapeutic strategies for treating those GBC patients in future clinical trials.

Parthenolide induces gallbladder cancer cell apoptosis via MAPK signalling

Objective

Parthenolide (PTL) has a wide range of clinical applications owing to its anti-inflammatory and antitumor effects. To date, the antitumor effect of PTL on gallbladder cancer (GBC) remains largely unknown. Therefore, we aimed to investigate the biological effects of PTL on GBC.

Methods

The cellular viability and proliferation of GBC-SD and NOZ cell lines after treatment with different concentrations of PTL were analyzed using the Cell Counting Kit-8 (CCK8)assay and colony formation assay. Apoptosis analysis was performed using flow cytometry. Hoechst staining was performed. RNA sequencing (RNA-seq) was performed to identify PTL-related genes and signalling pathways. Furthermore, we confirmed the involvement of these signalling pathways by qRT-PCR and western blotting. For the in-vivo experiments, a xenograft model was used to evaluate the effects of PTL on the proliferation of NOZ cells.

Results

PTL significantly inhibited GBC cell growth in vitro and induced apoptosis in the GBC-SD and NOZ cell lines in a dose-dependent manner. RNA sequencing data showed that the immune response and mitogen-activated protein kinase (MAPK) signalling pathways are closely associated with PTL-induced gallbladder cancer cell apoptosis. PTL upregulated BAX, cleaved PARP-1, cleaved caspase-3, cleaved caspase-9, P53 and decreased the expression of BCL-2, phosphorylated ERK, and phosphorylated MEK in vitro. Tumour volume and weight were also suppressed by PTL in vivo. Moreover, the effects of PTL on GBC cells might be mediated by the MAPK pathway.

Conclusion

PTL significantly inhibits gallbladder cancer cell proliferation and induces apoptosis through the MAPK pathway, which is a potential molecular reagent for treating GBC. However, further exploration is needed to verify the antitumor effects of PTL and its intracellular signalling mechanism.

GLI-1 polymorphisms of Hedgehog pathway as novel risk and prognostic biomarkers in melanoma patients

In adult organisms, deregulation of the sonic hedgehog (SHH) signaling pathway is significantly correlated with different malignancies. Currently, data associating genetic polymorphisms in the SHH pathway with melanoma are scarce and largely unknown. The objective of our study was to elucidate an association between gene polymorphisms in the SHH pathway and prognosis of melanoma skin cancer patients. The current study investigated the association of PTCH1 (rs357564), SMO (rs2228617) and GLI1 (rs2228224, rs2228226), polymorphisms with melanoma predisposition and prognosis. Single-nucleotide polymorphisms were assessed by TaqMan SNP Genotyping Assays. The study involved 93 melanoma patients and 97 individuals in the control group. Melanoma patients with the variant mutant genotype GG of GLI1 rs2228226 polymorphism had poorer overall survival and recurrence-free survival (P = 0.0001 and P = 0.037, respectively). The multivariate analysis revealed that disease progression [hazard ratio (HR) = 14.434, P = 0.0001] and the GLI1 rs2228226 polymorphism (HR = 4.161, P = 0.006) persisted as independent prognostic factors. Mutated allele carriers (combined heterozygous and mutated genotypes) for GLI1 rs2228224 G and GLI1 rs2228226 G allele significantly increased melanoma risk [odds ratio (OR) = 2.261, P = 0.007; OR = 2.176, P = 0.010]. Our study demonstrated that genetic variants in GLI1, downstream member of the HH signaling pathway, are the risk factors for melanoma susceptibility and it can be a novel marker for melanoma prognosis. As a crucial SHH signaling member, GLI1 can also be regarded as a novel drug target for anti-cancer treatment in melanoma.

Wnt ligands 3a and 5a regulate proliferation and migration in human fetal liver progenitor cells

Background

Since human fetal liver progenitor cells (hFLPC) can differentiate into multiple liver cell types in vitro and in vivo, hFLPC may be a suitable source for cell therapy and regeneration strategies. Imperative for effective clinical applications of hFLPC is the enhanced knowledge of growth factors that mediate and improve migration and proliferation. The canonical wingless/int-1 (Wnt) signal transduction pathway is known to play a key role in proliferation and migration of stem cells. So, we investigated a role for Wnt3a and Wnt5a ligands in regulating the proliferation and migration of hFLPC.

Methods

We used alamarBlue assay and transwell migration assay and examined proliferation and migration of hFLPC to Wnt3a and Wnt5a. In addition, the target genes of Wnt signal transduction pathway was identified using microarray analysis and validated by quantitative real-time polymerase chain reaction (qPCR).

Results

We found that Wnt3a or Wnt5a independently significantly increased migration and proliferation in a dose-dependent manner which was significantly inhibited by Wnt inhibitors Wnt-C59 or KN-62. Addition of Wnt3a to hFLPC resulted in increased mRNA expression of the known Wnt target genes Axin-2, DKK2, while Wnt5a increased CXCR7, all of which are closely associated with an enhanced proliferation capacity of stem cells.

Conclusions

Thus, we report that Wnt3a and Wnt5a may play an important role in the proliferation and migration of hFLPC by possibly regulating key target genes-involved in these processes. Incorporating recombinant human Wnt3a and Wnt5a in regenerative strategies using liver stem/progenitor cells might improve the process of liver regeneration.

New insights of the correlation between AXIN2 polymorphism and cancer risk and susceptibility: evidence from 72 studies

Background

Numerous studies have reported the correlation between AXIN2 polymorphism and cancer risk, but the results seem not consistent. In order to get an overall, accurate and updated results about AXIN2 polymorphism and cancer risk, we conducted this study.

Methods

An updated analysis was performed to analyze the correlation between AXIN2 polymorphisms and cancer risk. Linkage disequilibrium (LD) analysis was also used to show the associations.

Results

Seventy-two case-control studies were involved in the study, including 22,087 cases and 18,846 controls. The overall results showed rs11079571 had significant association with cancer risk (allele contrast model: OR = 0.539, 95%CI = 0.478–0.609, PAdjust = 0.025; homozygote model: OR = 0.22, 95% CI = 0.164–0.295, PAdjust< 0.001; heterozygote model: OR = 0.292, 95% CI = 0.216–0.394, PAdjust< 0.001; dominant model: OR = 0.249, 95% CI = 0.189–0.33, PAdjust< 0.001). The same results were obtained with rs1133683 in homozygote and recessive models (PAdjust< 0.05), and in rs35285779 in heterozygote and dominant models (PAdjust< 0.05). LD analysis revealed significant correlation between rs7210356 and rs9915936 in the populations of CEU, CHB&CHS, ESN and JPT (CEU: r² = 0.91; CHB&CHS: r² = 0.74; ESN: r² = 0.62, JPT: r² = 0.57), and a significant correlation between rs9915936 and rs7224837 in the populations of CHB&CHS, ESN and JPT (r²>0.5), between rs7224837 and rs7210356 in the populations of CEU, CHB&CHS, JPT (r²>0.5), between rs35435678 and rs35285779 in the populations of CEU, CHB&CHS and JPT (r²>0.5).

Conclusions

AXIN2 rs11079571, rs1133683 and rs35285779 polymorphisms have significant correlations with overall cancer risk. What’s more, two or more polymorphisms such as rs7210356 and rs9915936, rs9915936 and rs7224837, rs7224837 and rs7210356, rs35435678 and rs35285779 have significant correlation with cancer susceptibility in different populations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08092-0.

Aspirin and Statin Use and the Risk of Gallbladder Cancer

Simple Summary

The effects of aspirin on various gastrointestinal cancers have been extensively studied, but the potential protective effect of aspirin and statins on the prevention of gallbladder cancer (GBC) has not been adequately evaluated. The anticancer effect of aspirin has been attributed to direct inhibition of cyclooxygenase (COX)-2. Interestingly, increased expression of COX-2 has been documented in GBC. Hence, we hypothesized that aspirin could potentially have a preventive role in decreasing the risk of GBC. In this study, we demonstrated that the use of aspirin either alone or in combination with statins was associated with a strong reduction in risk of GBC.

Abstract

Aspirin and statin drugs have been associated with reduced risk of several gastrointestinal cancers, but their association with gallbladder cancer (GBC) has not been well established. We evaluated the association of aspirin and statins with the risk of GBC. Patients with GBC managed at Mayo Clinic between 2000 and 2019 were matched 1:2 with a general patient pool by age and sex. Univariable and multivariable logistic regression models were used to assess associations between GBC and aspirin or statin use. The analysis included 795 cases and 1590 controls, with a median age of 67 years. Aspirin or statin use alone or in combination was higher in controls (p < 0.001). Univariate analysis showed that the use of aspirin [odds ratio (OR): 0.11; 95%CI: 0.08–0.15] or statins (OR: 0.29; 95%CI: 0.20–0.40) and their combined use (OR: 0.18; 95%CI: 0.13–0.24) was associated with lower risk of GBC. Multivariable analysis revealed that aspirin (OR: 0.12; 95%CI: 0.09–0.16) and combined statins and aspirin (OR: 0.46; 95%CI: 0.31–0.67) were associated with lower risk of GBC. Aspirin alone or in combination with statins is associated with a strongly reduced risk of GBC. Further prospective studies are needed to confirm these results and to elucidate their mechanisms.

The association between three AXIN2 variants and cancer risk

Plenty of epidemiological studies have assessed the effects of AXIN2 polymorphisms on the risk of developing cancer, but the available results were somewhat inconclusive. Odds ratios (ORs) with 95% confidence intervals (CIs) were utilized to investigate the relationship between three AXIN2 variants (rs2240308 C/T, rs1133683 C/T, and rs4791171 A/G) and overall cancer susceptibility. In silico tools were undertaken to investigate the correlation of AXIN2 expression with cancer risk and survival time. Furthermore, we explored the serum expression of AXIN2 by enzyme-linked immunosorbent assay. A total of 4167 cancer patients and 3515 control subjects were evaluated. The overall results demonstrated that there was no major association of these polymorphisms on cancer risk. However, stratified analysis by cancer type showed evidence that rs2240308 C/T polymorphism had a lower risk in lung cancer (OR, 0.76; 95% CI, 0.63-0.92; Pheterogeneity  = 0.865) and prostate cancer (OR, 0.54; 95% CI, 0.35-0.84; Pheterogeneity  = 0.088) by heterozygote comparison. Similar results were indicated in Asian descendants and population-based studies. In silico analysis showed evidence that AXIN2 expressions in lung cancer and prostate cancer were lower than that in normal counterpart. High expression of AXIN2 may have longer overall survival time than low expression group for lung cancer participants. In addition, individuals who were CC/TC carriers had a higher serum expression level than TT carriers. In conclusion, this pooled analysis suggested that AXIN2 rs2240308 C/T variant may decrease both lung and prostate cancer susceptibility, particularly in Asian descendants and population-based studies. Future large scale and well-designed research are required to validate these effects in more detail.

New insights into the association between AXIN2 148 C/T, 1365 C/T, and rs4791171 A/G variants and cancer risk

BACKGROUND

Many epidemiological studies have investigated association of AXIN2 variants on overall cancer risks; however, the available results remain inconsistent.

METHODS

An updated analysis was conducted to ascertain a more accurate estimation of the correlation between AXIN2 148 C/T, 1365 C/T, and rs4791171 A/G polymorphisms and cancer risk. We also used in silico tools to assess the effect of AXIN2 expression on cancer susceptibility and overall survival time.

RESULTS

A total of 4281 cases and 3955 control participants were studied. The overall results indicated that AXIN2 148 C/T variant was associated with cancer risk (allelic contrast: OR = 0.88, 95% CI 0.77-0.99, P heterogeneity = 0.004; dominant model: OR = 0.82, 95% CI 0.69-0.96, P heterogeneity = 0.022), especially for lung and prostate adenocarcinoma. Similar results were observed in 1365 C/T polymorphism (OR = 0.71, 95% CI 0.61-0.98, P heterogeneity = 0.873; dominant model: OR = 0.66, 95% CI 0.47-0.94, P heterogeneity = 0.775). Moreover, in subgroup analysis by ethnicity, similar findings were obtained for Asian and Caucasian populations. Results from in silico tools suggested that AXIN2 expressions in lung adenocarcinoma were lower than that in normal group.

CONCLUSIONS

Our findings indicated that AXIN2 148 C/T and 1365 C/T variants may be associated with decreased cancer susceptibility.

Genetic landscape of gallbladder cancer: Global overview

Gallbladder cancer (GBC) is a rare malignancy of biliary tract cancer (BTC), characterized by late presentation and poor prognosis. It exhibits wide geographical as well as ethnical variations. So, diverse epidemiology along with etiological factors have been discussed in the current article. Present review unravels the germ line polymorphisms contributing to GBC susceptibility through candidate gene approach and GWAS. GBC is enriched with multiple mutations consisting of both passenger and driver mutations. The identification of the hotspot driver mutations which are involved in the etiopathogenesis of this cancer is necessary, before targeted therapies could be implemented clinically. Thus, this review sheds lights on both traditional low throughput methods along with high throughput NGS used to determine somatic mutations in cancer. With the advent of GWAS and high throughput sequencing methods, it is possible to comprehend the mutational landscape of this enigmatic disease. This article is the first one to provide insights into the genetic heterogeneity of GBC along with somatic mutational data from Catalogue of Somatic Mutations in Cancer (COSMIC) database. In addition, management of tumor heterogeneity as a therapeutic challenge has been discussed. Future goals involve liquid biopsy based research for better clinical management of the disease. Therefore, research efforts involving discovery of non- invasive markers for early stage cancer detection along with novel therapies should be directed.

Association of TERT-CLPTM1L and 8q24 Common Genetic Variants with Gallbladder Cancer Susceptibility and Prognosis in North Indian Population

Gallbladder carcinoma (GBC) is one of the common malignancy of the biliary tract. Several genome wide and candidate gene studies have reported associations between multiple cancer types and single-nucleotide polymorphisms on 5p15.33 and 8q24.21 loci. However, predisposition potential of these genetic variants has not been assessed in GBC. We performed the present study to assess the potential of five polymorphisms on 5p15.33 and one on 8q24.21 locus in GBC risk and treatment response in patients undergoing chemoradiotherapy. We extracted genomic DNA from peripheral blood and genotyped selected SNPs using TaqMan allelic discrimination assays in 523 GBC cases and 274 controls from the north-Indian population. Statistical tests were performed to assess the association of selected common genetic variants with gallbladder cancer susceptibility and prognosis. Binary logistic regression analysis showed significant association of TERT rs2736100C > A [OR(CI) = 0.690(0.515-0.924), p value = 0.013], CLPTM1L rs401681C > T [OR(CI) = 0.586(0.405-0.847), p value = 0.004], and CASC8 rs6983267G > T [OR(CI) = 1.629(1.215-2.186), p value = 0.001] with GBC risk. Further, using multivariate logistic regression, we observed that haplotype CLPTM1L Crs401681Crs31489 TERT Trs2853676Ars2736100 MIR4457 Grs4635969 [OR(CI) = 7.52 (1.79-31.52), p value = 0.0064] is significantly associated with poor treatment response. In survival analysis, Kaplan-Meier survival curves showed significantly poor survival and COX regression suggested significantly higher hazard ratio in TT genotype carriers of CASC8 rs6983267 [OR(CI) = 4.28(1. 07-17.10), p value = 0.040] as compared to major allele and heterozygous (GG+GT) genotypes in metastatic GBC cases. The study revealed that 5p15.33 and 8q24.21 genetic variants significantly influence GBC risk and treatment response in north-Indian population.

Comprehensive assessment and meta-analysis of the association between CTNNB1 polymorphisms and cancer risk

CTNNB1, encoding β-catenin, is a well-known tumor-related gene in the wnt signaling pathway. It has been reported that CTNNB1 polymorphisms are associated with cancer risk. However, the data were inconsistent. In this article, we conducted a systematic review for the researches related to the association of single nucleotide polymorphisms (SNPs) in CTNNB1 with overall cancer risk. Meanwhile, a series of inclusion and exclusion criteria were set to select articles for quantitative analysis. Consequently, eight case-control studies containing 4388 cases and 4477 controls were included in a meta-analysis of four highly studied CTNNB1 SNPs (rs1798802 A/G, rs4135385 A/G, rs11564475 A/G, and rs2293303 C/T). The association between each SNP and cancer risk was estimated by calculating odds ratios (ORs) and their 95% confidence intervals (95%CIs). The results showed rs1798802 (AA compared with GG: P=0.044, OR=0.72) and rs2293303 (TT compared with CC: P=0.002, OR=2.86; recessive model: P=0.006, OR=2.91; T compared with C: P=0.004, OR=1.19) polymorphisms were associated with overall cancer risk. In stratified analysis, rs4135385 polymorphism was found to elevate the risk in Caucasian or in gastrointestinal cancer subgroup. Additionally, rs2293303 conferred to an increased cancer risk when the source of control groups was hospital-based (HB). In conclusion, the three CTNNB1 SNPs were suggested to have the potential to be novel biomarkers for risk prediction of cancer in overall population or some specific subgroups. Our study could provide research clues for further related investigations.

Different effection of p.1125Val>Ala and rs11954856 in APC on Wnt signaling pathway

Colorectal cancer (CRC) is among the most common and fatal forms of solid tumors worldwide and more than two thirds of CRC and adenomas patients have APC gene mutations. APC is a key regulator in the Wnt/β-catenin signaling pathway but its roles in CRC remains to be elucidated. In this study, we compared APC genes between CRC patients and controls to determine possible associations of nucleotide changes in the APC gene with the pathways involved in CRC pathogenesis. All participants received physical and enteroscopic examinations. The APC gene was sequenced for 300 Chinese Han CRC patients and 411 normal controls, and the expression levels of genes in the signaling pathway were analyzed using Western Blotting. Statistical analyses were conducted using SPSS (version 19.0) software. We found that rs11954856 in the APC gene was associated with colorectal cancer and could increase the expression levels of APC, β-catenin, TCF7L1, TCF7L2 and LEF1 genes in the pathway in the CRC patients, demonstrating the involvement of APC in the pathological processes leading to CRC.

New Horizons for Precision Medicine in Biliary Tract Cancers

Biliary tract cancers (BTC), including cholangiocarcinoma and gallbladder cancer, are poor-prognosis and low-incidence cancers, although the incidence of intrahepatic cholangiocarcinoma is rising. A minority of patients present with resectable disease but relapse rates are high; benefit from adjuvant capecitabine chemotherapy has been demonstrated. Cisplatin/gemcitabine combination chemotherapy has emerged as the reference first-line treatment regimen; there is no standard second-line therapy. Selected patients may be suitable for liver-directed therapy (e.g., radioembolization or external beam radiation), pending confirmation of benefit in randomized studies. Initial trials targeting the epithelial growth factor receptor and angiogenesis pathways have failed to deliver new treatments. Emerging data from next-generation sequencing analyses have identified actionable mutations (e.g., FGFR fusion rearrangements and IDH1 and IDH2 mutations), with several targeted drugs entering clinical development with encouraging results. The role of systemic therapies, including targeted therapies and immunotherapy for BTC, is rapidly evolving and is the subject of this review.Significance: The authors address genetic drivers and molecular biology from a translational perspective, in an intent to offer a clear view of the recent past, present, and future of BTC. The review describes a state-of-the-art update of the current status and future directions of research and therapy in advanced BTC. Cancer Discov; 7(9); 943-62. ©2017 AACR.

New Horizons for Precision Medicine in Biliary Tract Cancers

Biliary tract cancers (BTC), including cholangiocarcinoma and gallbladder cancer, are poor-prognosis and low-incidence cancers, although the incidence of intrahepatic cholangiocarcinoma is rising. A minority of patients present with resectable disease but relapse rates are high; benefit from adjuvant capecitabine chemotherapy has been demonstrated. Cisplatin/gemcitabine combination chemotherapy has emerged as the reference first-line treatment regimen; there is no standard second-line therapy. Selected patients may be suitable for liver-directed therapy (e.g., radioembolization or external beam radiation), pending confirmation of benefit in randomized studies. Initial trials targeting the epithelial growth factor receptor and angiogenesis pathways have failed to deliver new treatments. Emerging data from next-generation sequencing analyses have identified actionable mutations (e.g., FGFR fusion rearrangements and IDH1 and IDH2 mutations), with several targeted drugs entering clinical development with encouraging results. The role of systemic therapies, including targeted therapies and immunotherapy for BTC, is rapidly evolving and is the subject of this review.Significance: The authors address genetic drivers and molecular biology from a translational perspective, in an intent to offer a clear view of the recent past, present, and future of BTC. The review describes a state-of-the-art update of the current status and future directions of research and therapy in advanced BTC. Cancer Discov; 7(9); 943-62. ©2017 AACR.

Gallbladder cancer epidemiology, pathogenesis and molecular genetics: Recent update

Gallbladder cancer is a malignancy of biliary tract which is infrequent in developed countries but common in some specific geographical regions of developing countries. Late diagnosis and deprived prognosis are major problems for treatment of gallbladder carcinoma. The dramatic associations of this orphan cancer with various genetic and environmental factors are responsible for its poorly defined pathogenesis. An understanding to the relationship between epidemiology, molecular genetics and pathogenesis of gallbladder cancer can add new insights to its undetermined pathophysiology. Present review article provides a recent update regarding epidemiology, pathogenesis, and molecular genetics of gallbladder cancer. We systematically reviewed published literature on gallbladder cancer from online search engine PubMed (http://www.ncbi.nlm.nih.gov/pubmed). Various keywords used for retrieval of articles were Gallbladder, cancer Epidemiology, molecular genetics and bullion operators like AND, OR, NOT. Cross references were manually searched from various online search engines (http://www.ncbi.nlm.nih.gov/pubmed,https://scholar.google.co.in/, http://www.medline.com/home.jsp). Most of the articles published from 1982 to 2015 in peer reviewed journals have been included in this review.

A multianalytical approach to evaluate the association of 55 SNPs in 28 genes with obesity risk in North Indian adults

OBJECTIVES

The aim of the study was to investigate the association of 55 SNPs in 28 genes with obesity risk in a North Indian population using a multianalytical approach.

METHODS

Overall, 480 subjects from the North Indian population were studied using strict inclusion/exclusion criteria. SNP Genotyping was carried out by Sequenom Mass ARRAY platform (Sequenom, San Diego, CA) and validated Taqman® allelic discrimination (Applied Biosystems® ). Statistical analyses were performed using SPSS software version 19.0, SNPStats, GMDR software (version 6) and GENEMANIA.

RESULTS

Logistic regression analysis of 55 SNPs revealed significant associations (P < .05) of 49 SNPs with BMI linked obesity risk whereas the remaining 6 SNPs revealed no association (P > .05). The pathway-wise G-score revealed the significant role (P = .0001) of food intake-energy expenditure pathway genes. In CART analysis, the combined genotypes of FTO rs9939609 and TCF7L2 rs7903146 revealed the highest risk for BMI linked obesity. The analysis of the FTO-IRX3 locus revealed high LD and high order gene-gene interactions for BMI linked obesity. The interaction network of all of the associated genes in the present study generated by GENEMANIA revealed direct and indirect connections. In addition, the analysis with centralized obesity revealed that none of the SNPs except for FTO rs17818902 were significantly associated (P < .05).

CONCLUSIONS

In this multi-analytical approach, FTO rs9939609 and IRX3 rs3751723, along with TCF7L2 rs7903146 and TMEM18 rs6548238, emerged as the major SNPs contributing to BMI linked obesity risk in the North Indian population.

Genetic polymorphisms of Wnt/β-catenin pathway genes are associated with the efficacy and toxicities of radiotherapy in patients with nasopharyngeal carcinoma

Radiotherapy (RT) is the normative therapeutic treatment for primary nasopharyngeal carcinoma (NPC). Single nucleotide polymorphisms (SNPs) of genes in Wnt/β-catenin pathway are correlated to the development, prognosis, and treatment benefit of various cancers. However, it has not been established whether SNPs of Wnt/β-catenin pathway are associated with nasopharyngeal tumorigenesis and the efficacy of RT in NPC patients. Therefore, in this study, we aimed to investigate the nine potentially functional SNPs of four genes in the Wnt/β-catenin pathway and genotyped these in 188 NPC patients treated with RT. To achieve this goal, associations between these SNPs and the RT's curative efficacy, as well as acute radiation-induced toxic reaction were determined by multifactorial logistic regression. We observed that catenin beta 1 gene (CTNNB1) rs1880481 and rs3864004, and glycogen synthase kinase 3 beta gene (GSK3β) rs3755557 polymorphisms were significantly associated with poorer efficacy of RT in NPC patients. Moreover, GSK3β rs375557 and adenomatous polyposis coli gene (APC) rs454886 polymorphisms were correlated with acute grade 3-4 radiation-induced dermatitis and oral mucositis, respectively. In conclusion, this study suggests that gene polymorphisms of Wnt/β-catenin may be novel prognostic factors for NPC patients treated with RT.

A let-7 microRNA binding site polymorphism in the KRAS 3'UTR is associated with increased risk and reduced survival for gallbladder cancer in North Indian population

PURPOSE

Gallbladder cancer is a lethal malignancy of hepato-biliary system with high incidence in North India, especially along gangetic plain. The let-7 microRNAs play a key role in regulating KRAS expression and a polymorphism in 3' untranslated region (rs61764370, T/G) of KRAS leads to its higher expression. This polymorphism is known to be associated with increased risk and prognosis of various cancers but its association with gallbladder cancer has not been evaluated. To address this research question, we evaluated whether rs61764370 variant is associated with gallbladder cancer susceptibility and clinical outcomes.

METHODS

In present case-control study, we enrolled 541 patients with gallbladder malignancy and 307 controls. Genomic DNA was obtained from peripheral blood and genotyping was performed using Taqman allelic discrimination assay.

RESULTS

Heterozygous (TG) individuals are at a significant higher risk for GBC as compared with wild genotype (TT) (p = 0.007, odds ratio = 2.56, 95 % CI 1.27-5.18). At allelic level, allele G has significant higher risk for GBC as compared with T allele (p = 0.008, odds ratio = 2.5, 95 % CI 1.25-5.01). Survival analysis reveals decrease in overall survival for heterozygous genotype (p < 0.0001, hazard ratio = 3.42, 95 % CI 1.21-4.20). Also, significant decrease in overall survival was observed for patient carrying allele G (p < 0.0001, HR = 2.89, 95 % CI 1.21-4.20) as compared with allele C.

CONCLUSIONS

We conclude that KRAS rs61764370 polymorphism is significantly associated with risk and prognosis of gallbladder malignancy in this endemic belt.