原发性肝细胞癌癌组织中p33^(ING1b)与p53基因的表达

Significance of p33 ~ (ING1b) and p53 gene expression in hepatocellular carcinoma

目的 研究p33ING1b与p5 3蛋白在原发性肝细胞癌中表达的相关性及ING1b基因在原发性肝细胞癌中的突变率。方法 应用免疫组织化学SP方法检测了 5 7例原发性肝细胞癌癌组织、5 1例癌旁肝组织及 12例正常肝组织中p33ING1b和p5 3蛋白的表达 ,并分析了原发性肝细胞癌癌组织中乙肝病毒 (HBV)的感染率 ;应用聚合酶链式反应 (PCR)联合单链构象多态性 (SSCP)方法检测了 2 8例配对癌及癌旁肝组织中ING1b基因两个外显子的突变情况 ,对有异常泳动条带的DNA片段分别克隆测序。结果 在 5 7例原发性肝细胞癌癌组织中 ,p33ING1b、p5 3蛋白的阳性率分别为 4 2 1%和 5 7 9% ,p33ING1b、p5 3表达均呈阳性者有 19例 (33 3% ) ,且两者在癌组织中阳性分布区域相同 ;p33ING1b蛋白表达与p5 3蛋白表达在癌组织中呈显著正相关 (r =0 783,P <0 0 1) ;配对癌旁肝组织及正常肝组织中p5 3蛋白表达均为阴性 ,p33ING1b蛋白在 13例癌旁肝组织及 2例正常肝组织中呈弱阳性表达 ;在 5 7例原发性肝癌组织中有 35例 (6 1 4 % )HBVX蛋白呈阳性 ,其病理类型均为肝细胞肝癌 ,在 5 1例癌旁肝组织中检出HBVX蛋白阳性者 39例 (76 4 7% ) ,癌组织中HBV感染与p33ING1b、p5 3蛋白表达均有关(P <0 0 1) ;PCR SSCP结果表明 ,ING1b基因在原发性肝细?

Objective To explore the significance of p33 ING1b protein expression and p53 protein expression and investigate the mutation rate of ING1b gene in hepatocellular carcinoma (HCC). Methods Immunohistochemical method was employed to detect the expressions of p33 ING1b and p53 proteins and the X antigen of hepatitis B virus (HBV) in 57 cases of HCC, 51 cases of surrounding non-tumor tissues surrounding HCC, and 12 cases of normal liver tissues; PCR-single strand conformation polymorphism (SSCP) was applied to reveal the mutation rates of two exons of ING1b gene in HCC. DNA fragments exhibiting abnormal shifting were cloned into PMD18-T vector and sequenced. Results The positive rates of p33 ING1b protein and of p53 protein were 42.1% and 57.9% respectively among the 57 cases of HCC. Both p33 ING1b protein and p53 protein were positive in 19 cases (33.3%) of HCC tissues, and they were distributed in the same areas, mostly in the nucleus. The expression of p33 ING1b was significantly correlated with that of p53 protein (r=0.783,P<0.01). The matched surrounding non-tumor tissues and normal liver tissues all showed negative p53 staining, while weak positive expression of p33 ING1b was observed in 13 cases out of the 51 non-tumor tissues and 2 cases out of 12 normal liver tissues. Thirty-five cases, all with hepatocellular carcinoma, out of the 57 HCC cases showed positive HBV X protein (76.4%). The correlation of HBV infection with the expression of p33 ING1b and p53 proteins was significant (P<0.01). PCR-SSCP showed that the mutation rate of ING1b gene in HCC was 7.1% (2/28). Conclusion The expression of p33 ING1b protein is significantly related to the expression of p53 protein in hepatocellular carcinoma; The existence of p33 ING1b may have some other p53-independent pathway; Gene mutation was not the main reason that ING1b loses its tumor suppressing function in HCC. HBV infection has a close relationship with p33 ING1b and p53 proteins expression.