CONSTITUTIVE EXPRESSION OF FGF2 BFGF IN NONTUMORIGENIC HUMAN PROSTATIC EPITHELIAL-CELLS RESULTS IN THE ACQUISITION OF A PARTIAL NEOPLASTIC PHENOTYPE/

Fibroblast growth factor 2 (FGF2), also known as basic fibroblast grow th factor (bFGF), belongs to the FGF family, which consists of at leas t 9 closely related members. FGF2 is a potent mitogen for fibroblasts derived from normal prostate and, to a lesser extent, for prostatic ep ithelial cells. Its role in the physiology of the normal prostate seem s to be limited to stromal cells, whereas in prostate cancer FGF2 may also have an autocrine/paracrine effect on epithelial cells. In order to better understand the effects of FGF2 on the prostatic epithelium, especially its role in the progression of prostate cancer by establish ing an autocrine-stimulation loop, we transfected FGF2 cDNA into a hum an prostatic epithelial cell line, PNTIA, immortalized with SV40 large -T antigen. This cell line is non-tumorigenic and expresses a high-aff inity FGF2 receptor, FGFRI/flg. We characterized 3 independent FGF2-tr ansfected clones and found that the establishment of an FGF2 autocrine loop on these cells led to (i) serum-independent growth, (ii) increas ed proliferation and (iii) anchorage-independent growth. Such results argue in favor of the possible action of FGF2 on progression of prosta te cancer via an FGF2 autocrine loop on epithelial cells. (C) 1997 Wil ey-Liss, Inc.