肝胆肿瘤组织中DNA依赖蛋白激酶的表达及意义

目的 通过检测不同类型肝胆肿瘤组织中DNA依赖蛋白激酶(DNA dependent protein kinase，DNA-PK)及调节亚基Ku70的表达水下，探讨其与肿瘤恶性程度和侵袭性的关系。方法 用免疫组化法险测47例肝胆肿瘤组织和部分癌旁组织中催化、IE基DNA-PKcs和Ku70蛋白的表达情况。结果 Ku70广乏表达于所检测的肿瘤组织中，其中腺癌和部分腺瘤表达量最高，但在不同恶性程度和侵袭性的肿瘤组织辛的表达差异无显著性。而DNAPKCS表达在不同类型肿瘤问存在明显差异，肝细胞癌阳性表达率为92．1％，显著高于胆管腺癌(65．3％)和胆囊腺癌(51．9％)(χ^2值分别为8．95、l2．42，P值分别为0．016和0．0l3)，乳头状腺瘤或胆管腺瘤不表达或弱表达。侵袭性腺瘤(癌)组织表达水平为61．2％，显著高于非侵袭性腺瘤(癌)(30．4％)(χ^2=16．23，P=0．004)。癌旁组织相对低表达DNAPKCS。结论 DNA-PKcs表达水平与肿瘤类型、恶性程度、转移或侵袭性有关，有可能成为肝胆肿瘤的一个新的生物标记物。

Expression of DNA-PK in hepato- and cholangio-neoplasms and its significance

Objective To characterize DNA-PKcs and Ku70 expressions in hepato- and cholangio-neoplastic tissues and the association with the degree of malignancy and invasiveness of the tumors. Methods The expression of DNA-PKcs and Ku70 was examined in 47 cases of hepato- or cholangio-neoplasm by immunohistochemistry. Results Ku70 was expressed in all of the neoplastic tissues examined and with a little variation in levels. The highest expression was observed in adenocarcinomas and adenomas. There was no statistically significant association between Ku70 expression level and the degree of their malignancy extent or invasiveness. In contrast to Ku 70, a wide variation in expression levels of DNA-Pkcs was observed among different types of neoplastic tissues. The highest ratio of positive expressing cells was detected in hepatocellular carcinomas (92.1%), which was significantly higher than that in cholangioadeno carcinomas (65.3%) and biliary cystadenocarcinomas (51.9%) ( x2 = 8.95, 12.42; P = 0.016 or 0.013). Low or no expression level was detected in papillary adenoma cases. DNA-PKcs expression of invasive adenomas and adeno-carcinomas (61.2%) was significantly higher than that of non-invasive adenomas and adenocarcinomas (30.4%) (x2 = 16.23, P = 0.004). There was no expression observed in the normal tissues adjacent to the tumors. Conclusion DNA-PKcs is expressed in hepato- and cholangio-neoplasms and its variable level of expression is associated with the types of the tumor and their degree of malignancy and invasiveness. DNA-PKcs could be recognized as a new biomarker for liver neoplasm.