Study On The Expression Of APEX1 And The Correlationship Of Its Single Nucleotide Polymorphisms With Hepatocellular Carcinoma

ObjectiveTo detect the expression of APEX1, HBV markers in hepatocellular carcinoma(HCC) and study the correlation of APEX1 and markers of HBV expression with invasion and metastasis of HCC. And the single nucleotide polymorphisms of APEX1 in 100 primary hepatocellular carcinoma cases from Fujian were detected, to investigate their relationship with HCC.MethodsThe expression of APEX1 protein,HBsAg and HBcAg were detected by immunohistochemistry (IHC) and the expression of APEX1 mRNA and HBV DNA were tested by in situ hybridization (ISH) in 130 cases of HCC samples, 96 non-neoplastic adjacent liver tissue samples, 46 non-neoplastic distant liver tissue samples, 5 normal liver tissue samples and 29 metastasis lesion samples. The correlations of APEX1, HBV markers to clinicopathologic parameters of HCC were also analyzed. Furthermore, We detected 3 single nucleotide polymorphisms (SNPs) in APEX1(Ile64Val,Asp148Glu and Gly241Arg) by ligase detection reaction (LDR), and analyzed the linkage disequilibrium (LD) and haplotype, to investigate the association of the SNPs with the risk of HCC .Results1. The results of immunohistochemistry and in situ hybridization showed that the expression of APEX1 decreased gradually in HCC, non-neoplastic adjacent liver tissues,non-neoplastic distant liver tissues and normal liver tissues(P<0.001), with the advance of the pathologic grade, the expression of APEX1 in HCC increased gradually(P<0.01). Comparing with the non-metastasis, the expression of APEX1 was increased significantly. The expression of APEX1 was much more stronger in capsule invasion than in non-capsule invasion. The percentage of staining style in cytoplasm and nuclear combinded was increased gradually in non-neoplastic distant liver tissues,non-neoplastic adjacent liver tissues, HCC and the metastasi(sP=0.001). The expression of APEX1 protein was corresponding to the expression of APEX1 mRNA.2. The expression of HBsAg and HBV DNA were stronger in non-neoplastic distant liver tissues and non-neoplastic adjacent liver tissues than in HCC and the metastasis(P<0.001). The expression of HBcAg was slightly stronger in non-neoplastic distant liver tissues and non-neoplastic adjacent liver tissues than in HCC, but there was no significance(P>0.05). Beside HBsAg showed negative correlation with APEX1 mRNA(P=0.014), there was no association between others(P>0.05).3. The results of LDR showed the Gly241Arg polymorphism was associated with the development of HCC(P=0.002), while Ile64Valå’ŒAsp148Glu polymorphisms not. There was linkage disequilibrium between Asp148Glu and Gly241Arg.Conclusions1. There was strong relationship between the expression of APEX1 and malignant clinical phenotype of HCC. Cytoplasmic localization of APEX1 was associated with the metastasis and invasion of HCC. Overexpression and cytoplasmic localization of APEX1 can be used as a poorly prognostic marker for HCC.2. The expression of APEX1 was not associated with some clinicopathologic parameters such as age, sex, size and histology type.3. The expression of HBsAg and HBV DNA in HCC were much lower than in non-neoplastic distant liver tissues and non-neoplastic adjacent liver tissues.4. Individuals carrying APEX1 Gly241Arg may have higher susceptibility to HCC. APEX1 G241A can be used as a marker to evaluating the risk of developing HCC.5. There was no association between the APEX1 Ile64Val and Asp148Glu with the development of HCC.