In vitro effects of epidermal growth factor (EGF) on growth of urological malignant tumor cells

It is well known that Epidermal Growth Factor (EGF) is a cell-regulating factor for variety of tissues in vitro including normal and malignant cells. Furthermore, Takano et al reported that a decreased expression of EGF receptor in clones of human cancer KB cell line might be one of the pleiotropic properties of multidrug-resistant cells. However, both the influence of EGF on human urological cancer cell lines and the relation between EGF receptors and sensitivities of antitumor drugs on these cell lines have not been fully described. We have studied the effects of EGF on growth of 4 transitional carcinoma cell lines of bladder (TCCaB), 1 squamous cell carcinoma cell line of bladder (SCCaB), 5 renal cell carcinoma cell lines (RCC) and 3 prostatic carcinoma cell lines (CaP), as well as the relationship between the number of EGF receptors and drug sensitivities of these cell lines in vitro against methotrexate, vinblastine, adriamycin, cisplatin and etoposide (VP16). The present results determined by the in vitro colony forming efficiency method showed that exogenous addition of EGF to cell cultures at 0.1 ng/ml stimulated the growth of SCCaB by 169.0%, and at 1 ng/ml inhibited that of RCC by 2.9%-79.0%, relative to control. The more EGF receptors by 125I-EGF binding assay, the higher inhibition of VP16 on the growth of these cell lines. These results suggested that EGF stimulated the growth of SCCaB and inhibited the growth of RCC in vitro, and we found that these phenomena were correlated with neither the number of EGF receptors nor affinities of that receptors.(ABSTRACT TRUNCATED AT 250 WORDS)