Antagonistic effect of EGF against TGF beta1 on transformed phenotype and tropomyosin expression of human lung carcinoma A549 cells.

Abstract

TGF beta1 suppressed the colony forming ability of human lung carcinoma cell line, A549 cells in a dose-dependent manner. Accompanying these changes, the levels of the expression of high-molecular weight tropomyosin (TM) isoforms, especially TM1 and TM2, were significantly increased in the TGF beta1-treated A549 cells in a dose-dependent manner. When A549 cells were treated with TGF beta1 (2.5 pM) and EGF (1 nM) simultaneously, anchorage-independent growth of A549 cells was restored. In these cells, the expression of high-molecular weight TM decreased. The results suggest that the levels of the expression of high-molecular weight TM may be involved in antagonistic effects of EGF and TGF beta1 on the anchorage-independent growth of A549 cells.