title: Growth inhibitors in plasma derived human serum.
abstract: It was reported previously that plasma derived human serum (PDS) inhibited the growth of cells established from malignant human breast tissues and the MCF-7 cell line but did not inhibit the growth of cells from nonmalignant mammary tissues, including the HBL-100 cell line. Plasma derived human serum was fractionated in the current study by molecular sieve chromatography on Sephadex G-100 in an effort to characterize the factor(s) responsible for inhibition. Plasma derived human serum contained several growth inhibitory fractions, which were designated G-1, G-2, G-3, and G-4. THe G-1 was associated with the lipoproteins and immunoglobulins of serum. The lipid portion of G-1 inhibited the growth of both MCF-7 and HBL-100 cells, whereas the protein fraction contained a low activity factor directed against MCF-7 cells only. The G-2 also inhibited MCF-7 cell growth at a low specific activity and was separated in the serum albumin fraction. The MCF-7 inhibitory activity in the G-3 fractions from individual donors fluctuated with the level of activity in the starting sera. The cell specific G-3 components were purified further by Sephadex G-100 superfine chromatography and gel electrophoresis. A tentative molecular weight of 50,000 was assigned to the G-3 inhibitor. The G-4 fraction consisted of small molecular weight materials migrating in advance of the column volume, which inhibited the growth of both cell lines.
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D006131:Growth Inhibitors / Q000097:blood* / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D008895:Milk, Human / Q000166:cytology; D008970:Molecular Weight
chemical_list: D006131:Growth Inhibitors