| Abstract: | A polypeptide growth factor has been isolated from serum-free medium conditioned by mouse PC13 embryonal carcinoma cells, which is strongly mitogenic for Swiss 3T3 fibroblasts. On a CM-2-SW high-performance liquid chromatography cation-exchange column at low pH, this growth factor elutes at a salt concentration very close to that of basic fibroblast growth factor (FGF). The growth factor is mitogenic for a mesodermal derivative of embryonal carcinoma (EC) cells, but not for differentiated derivatives with endodermal or ectodermal characteristics, again similar to FGF. The PC13-derived growth factor binds to heparin-Sepharose, and elutes from this column at similar salt concentrations as FGF. These data demonstrate that PC13 embryonal carcinoma cells produce a basic heparin-binding growth factor (HBGF). Since the initial purification steps are similar to those used by Heath & Isacke (EMBO j 3 (1984) 2957 7]) for isolation of a PC13 embryonal carcinoma-derived growth factor (ECDGF), which is cationic with a molecular weight (MW) close to that of FGF, the present heparin-binding growth factor (HBGF) is most likely identical with ECDGF. |
