Association Of MiR-106b And Its Target Gene ATF5 Polymorphism With The Risk Of Hepatocellular Carcinoma

Objective: Hepatocellular carcinoma(HCC)is one of the most common malignancies in the world and is known as the "king of cancer" due to its malignancy,rapid disease progression,and poor prognosis.It is currently believed that the occurrence of HCC is the result of multiple factors and multiple stages of evolution under the interaction of heredity and environment.Micro RNAs(miRNAs)are a class of highly conserved endogenous single-stranded noncoding small-molecule RNAs with a length of about 21-25 nucleotides(nt)during evolution.Mi RNAs degrade m RNA and/or suppress protein translation by binding the 3’untranslated region(3’UTR)of m RNAs,thus negatively regulate gene expression at post-transcriptional levels.Several researches have provided evidence to indicate that miRNA plays a significant role in the progress of HCC,and miRNAs are directly involved in multiple biological processes such as apoptosis,differentiation and migration of tumor cells.Single nucleotide polymorphism(SNP)refers to the DNA sequence polymorphism caused by the variation of a single nucleotide at the genome level.SNPs of miRNAs or in their binding sites on their target genes may compromise miRNA binding affinity,which may consequently alter individual susceptibility to cancer.Mi R-106 b can promote cancer cell proliferation and angiogenesis,inhibit tumor cell apoptosis,and participate in tumor development.In this research,the association between SNPs of miR-106 b and its target genes and HCC susceptibility in Guangxi is explored.Meanwhile,based on this study,the HCC related genetic susceptibility SNPs are identified.This study will present scientific evidence for primary prevention and early diagnosis of HCC in high-risk population.Methods: A total of 813 cases and 896 controls were included in our hospital-based case-control study.All subjects were recruited from the First Affiliated Hospital of Guangxi Medical University,the Guangxi Medical University Cancer Hospital and Affiliated Hospital of Guilin Medical University from January 2007 to April 2011.In this study,we conducted a screening on miR-106 b from the National Center for Biotechnology Information(NCBI)db SNP database(http://www.ncbi.nlm.nih.gov/)and NIEHS SNPinfo(http://snpinfo.niehs.nih.gov/)to seek candidate SNPs in Chinese population.Eventually,we selected two SNPs for this study: rs2261360(G>T)and rs1527423(A>G).In addition,we found that SNP rs8647(G>A)is located in the ATF5 gene by the Mir SNP(http://cmbi.bjmu.edu.cn/mirsnp).The three candidate SNPs Screening by bioinformatics methods(rs2261360 G>T,rs1527423 A>G,rs8647G>A)in miR-106 b and ATF5 were detected by using the Sequenom Mass ARRAY platform,and multivariate Logistic regression analysis was applied to estimate odds ratios(ORs)and 95% confidence intervals(CIs)for the associations between the above three potentially functional SNPs and its interaction with environmental factors to find the genetic susceptibility of HCC.Results: In HCC patients and controls,there were no statistically significant differences in the distributions of age and gender(P>0.05).However,the HCC patients were more likely to be smokers,drinkers and HBV infection individuals than controls(P<0.001).The genotype frequencies of miR-106 b rs2261360(G>T),rs1527423(A>G)and ATF5 rs8647(G>A)in the controls obeyed HardyWeinberg equilibrium(P>0.05).No statistically differences were found in genotype distributions for rs2261360、rs1527423 and rs8647 between the HCC cases and the controls(P>0.05).After adjusting for age,sex,smoking history,drinking history,HBV infection,it was found that the rs2261360 of miR-106 b had a statistically significant correlation with the risk of HCC.The results showed that individuals with the rs2261360 TG genotype had a significantly decreased risk of HCC than those with GG genotypes(TG vs.GG: OR = 0.64,95% CI = 0.46-0.88,P=0.006).In the dominant model,the rs2261360 T allele was associated with a significantly decreased risk for HCC(TG/TT vs.GG:OR = 0.71,95% CI = 0.53-0.96,P=0.023).In order to identify the relationship between rs2261360 polymorphism and HCC risk,the dominant genetic model of the rs2261360 were stratified by subgroups of age,gender,smoking history,drinking history,and HBV infection.TG/TT genotype of rs2261360 had the association with a decreased HCC risk in the population of 49 years old or younger(OR = 0.49,95%CI = 0.30-0.78,P=0.003),male(OR = 0.66,95% CI = 0.48-0.91,P=0.011),non-smoking population(OR = 0.61,95% CI = 0.42-0.89,P=0.010),nondrinking population(OR = 0.57,95% CI = 0.40-0.83,P=0.003)and HBV infection population(OR = 0.44,95% CI = 0.27-0.72,P=0.001),compared with GG genotype.Considering the potential combined effect of miR-106 b and ATF5 SNPs on risk of HCC,we combined them by the number of the putative risk genotypes(i.e.,rs2261360 GG,rs1527423 GA/GG and rs8647 GG)to assess their possible combined effect on HCC risk.We find that the combined risk genotypes had a statistically significant differences between the HCC cases and the controls(P<0.05).After adjusting for sex,age,drinking history,smoking history,HBV infection and other influencing factors,it was found that the combined 1‐3 risk genotypes(i.e.,rs2261360 GG,rs1527423 GA/GG and rs8647 GG)were associated with significantly increased risk of HCC(OR = 1.52,95% CI = 1.09‐2.12,P=0.013).Further stratification analysis showed that the combined 1‐2 risk genotypes increased HCC risk was more pronounced among male(OR = 1.57,95%CI = 1.10‐2.23,P=0.013),non-smoking population(OR = 1.61,95% CI = 1.06‐2.45,P=0.027),non-drinking population(OR = 1.73,95% CI = 1.16‐2.60,P=0.008),HBV-infected population(OR = 1.70,95% CI = 1.06‐2.73,P=0.029).However,no risk genotypes were found to interact with age,gender,smoking,drinking,and HBV infection(P>0.05).Conclusions: In summary,our results suggest that miR-106 b rs2261360 may be associated with risk of HCC.The miR-106 b rs2261360,rs1527423 and ATF5rs8647 polymorphisms may jointly contribute to the risk of HCC.