Role of genes for normal growth factors in human malignancy.

摘要: The human homologue of the v-sis oncogene encodes one chain platelet-derived growth factor (PDGF-2). Previous studies have shown that expression coding sequence for this induces malignant transformation NIH/3T3 cells. We demonstrate detection sis/PDGF-2 products indistinguishable from functional PDGF-2 homodimers in tumor These findings support concept product cells responsive to its proliferative actions can be an important step processes leading malignancy. Unlike sis/PDGF-2, which remains tightly cell-associated, another factor, termed transforming alpha (TGF alpha), is actively secreted. Expression vectors TGF failed induce primary transformed foci upon transfection despite high levels synthesized by these Moreover, transfectants selected secretion form colonies on contact inhibited monolayers or tumors inoculation nude mice. Thus, ability a autonomous vitro vivo dependent more than cognate receptors cell it synthesized.