肝细胞癌细胞系的细胞角蛋白异常表达及其机制

目的 利用体外培养的6株肝细胞癌细胞系研究肝细胞的细胞角蛋白（cytokeratin,CK0的异常表达及其与层粘连蛋白（laminin,LN）的关系。方法 应用能特异识别CK8，18，7，19，LN，及LN受体的抗体对肝细胞癌细胞系进行免疫酶组织化学染色；共聚焦显微镜技术对肝细胞癌细胞系的CK19和LN表达情况观察；应用Western blot技术对肝细胞癌细胞系的CK18，7和19的表达进行检测。结果 6株细胞系CD8和CD18全为阳性；CK7也全部阳性，但各株细胞反应细强度不同；其中4株细胞CK19为阳性，其余两株为阴性；LN免疫组化结果与CK19的结果一致；CK19和LN阳性物质共定位于同一癌细胞的细胞质中，所有LN明显阳性的细胞都为CK19免疫反应阳性。所有6株细胞系都表达LN受体。结论 肝细胞癌细胞系的细胞角蛋白表达不同于正常肝细胞，常出现CK7和CK19的异常表达，且CK19和LN的共定位，提示LN可能对CK19的表达起诱导作用。

Abnormal expression of cytokeratins in hepatocellular carcinoma cell lines and its mechanism

AIM To study the abnormal expression of cyto-keratins (CKs), as well as its association with laminin(LN), in hepatocellular cell lines growing in vitro. METHODS Expression of CK8, CK18, CK7, CK19, LN and LN receptor, as well as their possible association, in six hepatocellular carcinoma cell lines was demonstrated using immunocytochemical, confocal laser scanning microscopy and Western blotting approaches. RESULTS CK8 and CK18 were expressed in all of the six cell lines examined. CK7-immunoreactivity was also present, but in different levels, in all the cell lines. CK19 was positive in four, and negative in two cell lines, correlating well to LN-immunoreactivity. The positive products of both molecules were present in the same cells as demonstrated by laser confocal scanning microscopy. LN receptor was also expressed in all the cell lines. CONCLUSION Abnormal expression of CK7 and CK19 occurred frequently in hepatocellular carcinoma cells growing in culture. CK19 and LN were expressed in the same hepatocellular cell lines, localized often in the same cells. These data provide strong evidence for an inductive role of LN in the abnormal CK19 expression.