Risk Factor Of CYP2E1Rsal/PstI Polymorphism In The Morbidity Of Liver Cancer: A Meta-analysis

Background: Primary liver cancer is a common malignant tumor with poorprognosis. The annual incidence of liver cancer in China accounts for about55%in the world. The rate of liver cancer related death is ranked in secondjust next to the lung cancer. It is usually in the late stage when it wasdiagnosed due to asymptomatic and lack of specific and sensitive biomarkerfor earlier diagnosis. Therefore, early diagnosis and treatment for liver cancerhas become a very important issue in the field. CYP2E1is a member of theMonooxygenase cytochrome P super-family. It is highly expressed in theendoplasmic reticulum and inner membrane of mitochondrial of cells fromliver, stomach, intestine, kidney, lung and other important organs. Its functionmainly involved in oxidative stress, drug metabolism and endogenoussubstance transformation. The single nucleotide polymorphism (SNP) ofCYP2E1gene were found at the5’ flank area, most commonly PstI1239G>C(rs3813867) and RsaI-1055C>T (rs2031920), and can lead to change ofexpression level and activity of CYP2E1. Some studies have shown that theSNP of CYP2E1gene has certain relevance to the tumor in the respiratorysystem and the digestive tract. Recently, lots of researches focuses on thecorrelations between the gene polymorphism and the risk of liver cancer,however, the conclusion on association between PstI/Rsal polymorphism andthe risk of liver cancer has not been clearly elucidated. It could be due tomany reasons, including limited sample size among each individual studies. Thus, we perform this meta-analysis on pervious published clinical study toclarify the association between CYP2E1RsaI PstI polymorphismin and therisk of liver cancer.Materials and methods: We searched the literatures from the databases ofPubmed, Embase, Web of search Science, Cochrane Library, CBM, CNKI,Wanfang database for all the relevant articles regarding the CYP2E1PstI/Rsalpolymorphism and the risk of liver cancer. According to the inclusion andexclusion criteria, a total of16articles with4684patients in total wereselected, including1737cases of liver cancer and2947cases of control. Metaanalysis was performed with stata12.0software.Results: The comparisons were carried out under5genetic modes: dominantc1c2/c2c2vs c1/c1(OR=0.987[0.853,1.141]), homozygous c2c2vs c1c1(OR=0.767[0.526,1.119]), heterozygous c1c2vs c1c1(OR=1.005[0.854,1.182]), recessive c2c2vs c1c2/c2c2(OR=0.771[0.530,1.122]), and allelecontrast C2vs C1(OR=0.947[0.828,1.082]), respectively. The data showedthere was no significant correlation between the CYP2E1RsaI/PstIpolymorphism and risk of liver cancer in all of the5modes. There were alsono correlations between the subgroup analyzed by sources and the race.Conclusion: There is no significant correlation between the CYP2E1RsaI/PstI polymorphism and the risk of liver cancer. However, the studiesregarding gene polymorphism is worth to be further developed. It mayprovide a new approach for screening, early diagnosis, grading and predictionthe prognosis of liver cancer.