[Selective heterologous communication among human lung epithelial cells, fibroblasts, and lung cancer PG cells].
OBJECTIVE: To further understand the roles of gap junctional intercellular communication in carcinogenesis and progression of human lung cancer. METHODS: The heterologous communication was characterized among human lung epithelial cells HLEC, human lung fibroblasts HLF, human lung giant carcinoma PG cells and its Cx43 transfectants PG/C4 by using a preloading assay. Cx43 immunofluorescent staining and Northern blot were performed to examine Cx43 gene expression. RESULTS: Although both human lung fibroblasts HLF and epithelial cells HLEC expressed Cx43 and had very strong homologous communication, HLEC cells were unable to communicate with HLF cells. The human lung carcinoma cell line PG was defective of both homologous communication, and heterologous communication with its epithelial origin HLEC. Transfection of Cx43 into PG cells, which rescued PG cells' homologous communication and enhanced heterologous communication with HLF cells, could restore heterologous coupling with HLEC cells. CONCLUSION: Selective heterologous communication exists among different kinds of human lung cells, when human lung carcinoma cells lost coupling with its epithelial origin, Cx43 gene expression is not enough to establish heterologous communication between them.