Platelet-derived growth factor (PDGF) enhances the growth of Moloney sarcoma virus-induced tumors in mice.

The intramuscular (i.m.) administration of bovine or human platelet derived growth factor (PDGF) had a marked potentiating effect on the growth of Moloney sarcoma virus (MSV)-induced tumors in Balb/c mice. PDGF had the tumor-promoting-activity when administered i.m. on the side of inoculation of MSV two days after the virus, and subsequently every second day for 2-3 weeks. The extent of MSV-induced tumor promoting activity of PDGF was age and sex-related. In view of the recently described antagonism in action between growth factors and interferons it is suggested that both families of hormones play an important role in controlling the neoplastic proliferation.