Case-Control Study On The Association Of Hepatocellular Carcinoma With Genetic Polymorphisms Of CYP3A4 And CYP3A5 In Province Of Guangxi-High-Incident Area And Low-Incident Area

Background and object:Hepatocellular carcinoma(HCC)is one of the highest incident malignant tumors in China.A chronic inflammation caused by hepatitis B virus and Aflatoxin B1(AFB1)usually are the major factors of which induced the HCC.But the incidences of HCC for those people who often exposed to AFB1 and be infected by HBV are deferent.It's just implying that genetic is a much important factor in HCC.Only when AFB1 had been changed into AFB1-exo-8,9-epoxide(AFBO)induced by cytochrome P450(CYP450), its function induced mutation present.CYP3A enzyme is the most important part in the family of CYP450,including CYP3A4 and CYP3A5.It is the polymorphism that mainly influences the express level and the activity of protein.In order to explain the what's the function of CYP3A in HCC developing,we had studied the potential relationship between HCC and the two kinds of gene by two groups of patients come from different area in province of GuangXi—high-incident area and low-incident area.Method:We had collected 72 cases of HCC tissues which had been diagnosis by Dr.of the Department of Pathology of the Medical University of GuangXi from 2005,12—2006,9.We examed the expression of mRNA of the CYP3A4 and CYP3A5 by reverse transcription polymerase chain reaction (RT-PCR)and analysised the line of electrophoresis.The result were used to analyse the relationship between the expression of CYP3A4mRNA,CYP3A5mRNA in HCC and the information of pathology and clinic(including hepatitis B virus,pathological stage,the level of serum alpha-fetoprotein (AFP),the diameter of tumor and the presence of metastasis).PCR-RFLP assay was used for the analysis of the polymorphism of the CYP3A5.Result:1.The RT-PCR consequence of the expression of CYP3A4 mRNA in HCC,HCC surrounding tissue in high-incident area and low-incident area and the normal tissue of hepatic angioma,the results respectively are 0.58±0.07,0.51±0.07;0.67±0.05,0.48±0.05 and 0.98±0.08.The difference between HCC and the HCC surrounding tissue is not remarkable(P＞0.05),but HCC and HCC surrounding tissue compared with the normal tissue of liver,the difference is remarkable(P＜0.05).The difference between HCC in high-incident area and low-incident area is not remarkable,(P＞0.05).The positive rate of CYP3A4 mRNA in HCC was significantly correlated with pathological stage and the hepatitis B virus(P＞0.05),but not correlated with the level of serum AFP,the diameter of tumor and the presence of metastasis(P＞0.05).2.The RT-PCR consequence of the expression of CYP3A5 mRNA in HCC,HCC surrounding tissue in high-incident area and low-incident area and the normal tissue of hepatic angioma,the results respectively are 0.95±0.10,0.62±0.09;0.67±0.11,0.56±0.21 and 0.48±0.09,the consequence of CYP3A5 mRNA in HCC is higher than the HCC surrounding and the normal tissue of liver,the difference is remarkable(P＜0.05).The difference between high-incident area and low-incident area is remarkable(P＜0.05).The positive rate of CYP3A5 mRNA in HCC was significantly correlated with pathological stage and the hepatitis B virus(P＜0.05),but not correlated with the level of serum AFP,the diameter of tumor and the presence of metastasis(P＞0.05).3.By correlation analysis:The express of CYP3A4mRNA of 40 cases of HCC tissues in high-incidence area, 32 cases of HCC tissues and 12 cases of the normal tissue of liver is negative correlation to CYP3ASmRNA(r=-0.184.P＜0.05).4.Consequence of PCR-RFLP assay:CYP3A5~*1 allele frequency and the proportion of (CYP3A5~*1/~*1+ CYP3A5~*1/~*3)genotypes are both higher in Guangxi in high-incident area population,as compared with the reports in Guangxi low-incident area population and the normal tissue of liver.There are significant differences(P＜0.05).Conclusion:①The expression of CYP3A4mRNA In high-incidence area and low-incidence area of HCC are lower than the normal tissue of hepatic angioma,we suppose that the high level of expression of CYP3A4 might be related to the detoxicating of AFB1②The level of expression of CYP3A5 mRNA In high-incidence area of HCC is higher than the low-incidence area and the normal tissue of hepatic angioma,we suppose that the high level of expression of CYP3A5 might take part in the morbility of AFB1 related HCC;③The heterogeneity of CYP3A5~*1 certainly is higher in high-incidence area than the low-incidence area,We speculate that CYP3A5 mi ght take part in the morbility of AFB1 related HCC.