ABSTRACT
Objective To investigate AXIN2 mRNA expression level in hepatocellular carcinoma (HCC) , and to analyze the effect of AXIN2 gene methylation status on its mRNA expression and HCC genesis and development. Methods Fifty-three surgical excised HCC specimens and paired adjacent non-cancerous specimens, seven normal liver specimens and five HCC cell lines were collected. The expression of AXIN2 at mRNA level and the methylation status of AXIN2 gene promoter were determined by quantitative PCR. Results The expression of AXIN2 mRNA was lower in HCC tissues (0.1629 + 0.0679) than that in adjacent non-cancerous tissues (0. 4155 + 0. 2330), and there was significant difference (Z= -2. 567, P = 0. 010). The methylation level of AXIN2 gene in HCC and adjacent non-cancerous tissues (39. 77% ±3. 89%, and 36. 92% ±2. 81%) was significantly higher than that in normal liver tissues (7. 38% ±2. 40% , t=-3. 663 ,P = 0. 009;t= -4. 591 ,P = 0. 007).AXIN2 gene was hypermethylated in all five HCC cell lines. There was a negative correlation between AXIN2 mRNA expression level and the degree of methylation ( r = -0. 458, P = 0. 032). The methylation level was higher in TNM Ⅲ patients of HCC than that in TNM Ⅰ and Ⅱ patients (P =0.008). Conclusion The down-regulation of AXIN2 gene mRNA expression is correlated with its hypermethylation status. The low expression of AXIN2 mRNA and the abnormal methylation of promoter may be one of the important mechanism of HCC genesis and development.