肝细胞癌hOGG1 mRNA及其蛋白的表达

Expression of hOGG1 mRNA and protein in hepatocellular carcinoma

目的:通过检测DNA修复酶hOGGlmRNA及其蛋白在肝细胞癌中表达程度,探讨hOGGl在肝细胞癌发生、发展中的作用.方法:应用RT-RCR研究正常肝细胞株L-02、肝癌细胞株SMMC7721,HepG2和肝癌(26例)及癌旁组织(21例)中hOGGlmRNA的表达,同时用免疫组织化学方法检测了上述肝癌组织(17例)及癌旁组织(15例)中hOGGl蛋白的表达.结果:三株细胞均有hOGGlmRNA表达,但hOGGlmRNA在正常肝细胞株L-O2中的表达显著低于肝癌细胞株SMMC7721、HepG2中的表达(分别为0.270±0.014,0.66±0.011,0.624±0.020,P<0.05).肝癌组织hOGGlmRNA表达较癌周组织明显降低(P<0.05).HOGGl蛋白肝组织表达阳性率为87.2%,主要在肝细胞胞质表达,在肝癌组织中表达比癌周组织明显降低(P<0.05).结论hOGGlmRNA及其蛋白在肝癌细胞株及癌周组织中表达量升高。

AIM: To study the expression of DNA repair enzyme hOGG1 mRNA and protein in nomal liver cell, hepatoma cell lines and hepatocellular carcinoma (HCC) tissues, and to investigate their function in the progress of HCC. METHODS: Expression of hOGGl in normal liver cell L-02, hepatoma cell lines HepG2, SMMC7721 and HCC tissues (26 cases) as well as surrouding tissues of HCC (21 cases) were detected by semi-quantitative reverse-transcription polymerase chain reaction. hOGG1 protein was detected in corresponding HT tissues (17 cases HT) and their surrouding liver tissues (15 cases HST) by immunohistochemistry. RESULTS: The expression level of hOGGl mRNA in nomal liver cell line was lower than that in two hepatoma cell lines (0.270±0.014 vs 0.662±0.011, 0.624±0.020, P<0.05). The expression of hOGGl mRNA in HepG2 was similar to that in SMMC7721. The expression of hOGGl mRNA in HT was lower than that in HST (P<0.05). hOGGl protein was 87.2% (41 of 47) positive in HT and HST and was mainly distributed in liver cells. The protein level of hOGGl in HCC tissues was correspondingly lower than in their surrouding tissues (P<0.05). CONCLUSION: Overexpression of hOGGl in hepatoma cell lines and the surrouding liver tissuses of HCC may be one of the key events which promote the malignant growth. These results suggest a role for hOGGl expression in the course of the multistage process of carcinogenesis in hepatocellular carcinoma.