蛋白激酶Cα过表达导致正常人胚肺成纤维细胞生长失调的研究

Disordered Growth Control in Human Embryonic Lung Cells Caused by Overexpression of Protein Kinase Cα

采用自行构建的过表达ＰＫＣα亚类的正常人胚肺细胞模型，观察到细胞生长加速，血清依赖性明显下降，细胞形态发生变化，单层培养丧失接触抑制性，出现岛状生长，与对照组细胞相比，贴壁依赖性下降，在软琼脂中能形成小集落，细胞中微丝发生部分解聚，进一步检测观察到细胞中与转化密切相关的ｒａｓ癌基因表达明显增强，抑癌基因ｐ５３表达下降．首次表明在正常人胚肺细胞中ＰＫＣα的过表达直接导致细胞增殖加速，并可诱导出现部分转化特征．因此，ＰＫＣα的过表达与活化可能在细胞多阶段致癌过程中发挥着重要作用，而癌基因表达的增强与抑癌基因表达减弱可能是其作用分子机理之一．

By using human embryonic lung cells (NLTS) overexpressing protein kinase Cα constructed, it was found that cells displayed enhanced growth rate,apparently reduced dependence on serum, and altered cell morphology. Dense fosi developped, when maintained in monolayer culture. NLTS cells overexpressing PKC α lost the ability of contact inhibition. In contrast to control cells,anchorage dependence decreased and small colonies formed in soft agar. The partial depolymerization of the microfilaments was displayed in NLTS cells. Expression of the oncogene ras which is related to cell transfomation increased obviously,whereas expression of tumor-suppressor gene p53 decreased in NLTS cells. In the present work we indicated the first evidence that specific elevation of the PKC α level directly affected the increase of growth and the transforming phenotype of cells. The activation of PKC α may be of central importance in the process of multistage carcinogenesis. The increased expression of oncogene and decreased expression of tumorsuppressor gene may be one of the molecular mechanisms of the effect of PKC α.