间隙连接蛋白Cx43在人胚肺和肺癌细胞表达的研究

细胞与细胞之间通过细胞膜上的间隙连接通道交换小分子和离子进行细胞间通讯，对细胞增殖分化调控和机体内环境稳定有重要作用。用间隙连接蛋白Ｃｘ４３ｃＤＮＡ探针Ｎｏｒｔｈｅｒｎ印迹杂交，Ｃｘ４３抗体免疫荧光染色和罗氏黄荧光染料传输方法检查，正常人胚肺细胞的Ｃｘ４３在ｍＲＮＡ和蛋白水平有高表达，Ｃｘ４３蛋白免疫荧光分布在间隙连接的部位，细胞间隙连接通讯功能明显。与正常相反，人肺癌ＰＧ系细胞Ｃｋ４３无论在ｍＲＮＡ或蛋白质水平都无表达，细胞通讯功能缺陷。结果表明Ｃｘ４３在培养的人胚肺细胞有功能性表达。人肺癌ＰＧ细胞通讯功能缺陷与Ｃｘ４３基因转录抑制有关。对Ｃｘ基因的抑癌基因性质进行讨论。

EXPRESSION OF GAP JUNCTION PROTEIN CX43 IN CULTURED NORMAL HUMAN EMBRYONIC LUNG CELLS AND LUNG CARCINOMA CELLS

This report concerns the expression of the gap junction protein connexin (Cx)43 in malignant and normal human lung cells.By using Northern hybridhation analysis, Cx43 immunofluorescent staining and Lucifer Yellow dye transfer methods,high level of Cx43 mRNA and protein expression was revealed in cultural nounal human elnbryothe lUng all.The Cx43 protein was locatal at regions of Cell inelnbrane and the induce of Cell contact comeponding to gap junctions. The function of gap junctional inteedtilar cornxnunication was shown by effident dye transfer. In contrast to normal,the malignant human lung cadriorna PG Cells expansed neither Cx43 InRNA nor the Cx43 protein. These tumor Cells were defative o f gap junctional interCellular communication funCtion.The results indicate thatta) Connexin 43 expel funCtionally in nounal human lung Cells(b) Inhibition or down-regtilation of Cx43 gene tranScription is responsible for the defer of gap junCtional intercellular communication in human lung carcinoma PG Cells. The roles of Cx43 gene as tumor suppussor is discussed.