Antagonistic effect of EGF against TGF beta1 on transformed phenotype and tropomyosin expression of human lung carcinoma A549 cells.
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.
Tada
A
A
Chiba City Health Center, Mihama-ku, Chiba 261-8755, Japan.
Kato
H
H
Hasegawa
S
S
D002448:Cell Adhesion / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000187:drug effects; D010641:Phenotype; D020033:Protein Isoforms; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D053773:Transforming Growth Factor beta1; D014335:Tropomyosin / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured / Q000187:drug effects
D020033:Protein Isoforms; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D014335:Tropomyosin; D004815:Epidermal Growth Factor