Human Fibroblasts (KMST-6/Ras Cell Line) Transformed with ⁶⁰Co Gamma-Rays and C-Ha-ras Oncogene Produce a Large Amount of Granulocyte Colony-Stimulating Factor(G-CSF); Production Is Enhanced by cAMP, Theophylline, and Butyrate

Human fibroblasts (KMST-6/RAS cell line), which was malignantly transformed in vitro with ⁶⁰Co gamma-rays and the c-Ha-ras oncogene, produced a large amount of granulocyte colony-stimulating factor (G-CSF). The production was greater during the logarithmic growth phase than during the stationary phase. cAMP and theophylline, alone or in combination, and butyrate significantly enhanced G-CSF production, but dexamethasone or 5-azacytidine did not. Enhanced production of G-CSF by these agents was regulated at the posttranscriptional level. Neither the expression of the ras oncogene nor the tumorigenicity of the cells correlated with the production of G-CSF.