title: Growth hormone modulation of murine erythroleukemia cell growth in vitro.
abstract: There are few studies showing a biological effect of growth hormone (somatotropin) on cell proliferation in vitro at physiological concentrations. We report here that Friend virus-infected erythroleukemia cells are responsive to growth hormone in vitro. Using a serum-free clonogenic assay we found as little as 0.1 ng of human growth hormone per ml caused a prominent stimulation of cell proliferation. Peak activity of human growth hormone occurred at 200 ng/ml, resulting in a 2-fold increase in cloning. Human chorionic somatomammotropin and the Cys(Cam)53-hGH(1-134) fragment of human growth hormone were also active, but a biologically inert oxidized human growth hormone had no growth-promoting effect in vitro. Cell proliferation was stimulated by insulin with peak potentiation occurring at 1 ng/ml, and prolactin had a demonstrable stimulatory effect between 50 and 100 ng/ml. These observations indicate that growth hormone and related polypeptides have a direct effect on the in vitro proliferation of erythroleukemia cells in the absence of serum. The results confirm a direct action of growth hormone on mammalian cells and suggest that pituitary hormones may affect leukemic cell growth.
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects*; D002460:Cell Line; D005622:Friend murine leukemia virus; D013006:Growth Hormone / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology; D004915:Leukemia, Erythroblastic, Acute / Q000473:pathology*; D007942:Leukemia, Experimental / Q000473:pathology; D010928:Placental Lactogen / Q000494:pharmacology; D011388:Prolactin / Q000494:pharmacology
chemical_list: D007328:Insulin; D011388:Prolactin; D013006:Growth Hormone; D010928:Placental Lactogen