Antiproliferative effect of trapidil on PDGF-associated growth of human glioma cell lines in vitro.

The effects of trapidil on platelet-derived growth factor (PDGF)-associated growth of glioblastoma cells were studied. The assessment using PDGF-dependent rat lung endothelium cells revealed secretion of a PDGF-like factor from SF-126 cell line but not from SF-188. Human recombinant PDGF stimulated proliferation of both these glioblastoma cell lines. The anti-PDGF monoclonal antibody inhibited the growth of SF-126 more than SF-188. The results suggest the presence of an autocrine growth mechanism in SF-126 cells mediated by PDGF. The growth of both SF-126 and SF-188 cells was suppressed by trapidil, a specific PDGF antagonist, at 10 and 50 micrograms/ml, respectively. The proliferative response to exogenous PDGF and the antagonistic effect of trapidil were greater in the SF-126 cell line. In addition, trapidil markedly reduced production of prostaglandin E2 in both glioblastoma cell lines. This anti-proliferative effect on malignant glioma cells suggests that trapidil might be a new therapeutic agent for malignant gliomas.