The Association And Mechanism Of Patatin-like Phospholipase Domain-containing 3 Gene And Hepatitis B Virus Associated Hepatocellular Carcinoma

Genetic factors play an important role in the development of hepatoce1 lular carcinoma(HCC). Current research has confirmed that PNPLA3 rs738409 [G](code:I148M) gene polymorphisms is significantly associated with HCC. But whether PNPLA3 I148 M gene polymorphisms is the independent factor of HCC, and how it results in the damage of liver is still unclear. This study analyzed the function and possible mechanism of variant at individual, cellular and molecular levels. The goal of this research is to explore the relationship of PNPLA3 rs738409 G polymorphism with HBV-related HCC in Han population of Qingdao, and further investigate the impacts of NPLA3 rs738409 G polymorphism and genetic factors on such patients.Firstly, we studied the relationship between PNPLA3 I148 M variant and HBV-related HCC in Han population of Qingdao. The study included 230 HBV-related HCC patients,219 chronic hepatitis B(CHB) patients and 254 healthy controls. We used polymerase chain reaction and genotyping method to examined genotypes in blood samples. The results suggest that allele frequency distribution of rs738409 G were 24.3% in HCC patient, 12.8% in CHB patients and 7.17% in control(P<0.05). This had statistical signification(P<0.05). Non-conditional logistic regression showed that, comparing with C gene carriers, odds ratio of occurrence of HCC was 3.974(95%CI: 2.712-5.824,P=0.000) and of CHB was 1.700(95%CI: 1.179-2.451, P =0.004) in G gene carriers.After adjusted for age, sex with unconditional logistic regression model, odds ratio of occurrence of HCC was 4.099(95%CI:2.783-6.036, P=0.000)and that of CHB was1.709(95%CI:1.182-2.471, P=0.004)in G gene carriers. PNPLA3 I148 M variant was significantly associated with the level of serum AST、ALT、TB、TC and TBA in HCC group. The level of serum AST 、ALT 、TG、TC、and TBA were higher in variant genotype than that of the wild genotype(P <0.05). The results suggested that carriage of the PNPLA3 I148 M variant is not only associated with the occurrence anddevelopment of HBV-related HCC and CHB but also with liver damage in Han population of Qingdao.Secondly, we studied the role of PNPLA3 I148 M variant in cell level and molecular level through the cultured hepatocytes. We successfully built the recombinant lentivirus vectors containing PNPLA3 gene and Hep G 2.2.15 cells express PNPLA3.T PNPLA3 protein was overexpressed in Hep G2.2.15 cells with Western blot test. The expression of HBV DNA content, IL- 8 and p53 in m RNA and protein level were tested respectively.Compared with the control group and wild type group, The I148 M variant possessed a higher effect in the amount of HBV DNA and the expression level of inflammatory cytokines IL- 8 in variant group. But the statistical tests is not found(P > 0.05). The results suggested that PNPLA3 I148 M has no influence on hepatitis B virus and IL- 8.But the expression of p53 in m RNA and protein level was significantly increased in variant type group compared with empty virus and wild type group. The results suggested that PNPLA3 I148 M gene polymorphism can influence liver cancer cells trough regulate the expression of tumor suppressor gene p53. Based on these results and further research, maybe we can provide basic data support for the prevention and control of HBV according to the patients’ genotypes in the future.