[Hormone-dependent expression of oncovirus genomes in stable mouse mammary cancer cell line GR and RIII].
The expression of MuMTV and MuLV major polypeptides and extracellular revertase activity (RA) in relation to the treatment with insulin (INS), dexamethasone (D) or both hormones was studied in four clones derived from two mammary carcinoma (MC) stable cell lines, RIII/mt and GR/mt. In the cells growing in media without hormonal supplementation or with either insulin or dexamethasone alone the expression of p27 MuMTV was poor, in cultures treated with dexamethasone alone a slight increase in Mg++-dependent RA could be detected suggesting formation of A particles. A 10-fold increase of RA and gp52 MuMTV expression resulted only from the treatment with insulin which induced visible morphological changes in the cells from fibroblast-like towards epithelium-like patterns and formation of "domes". The hormones studied exerted no detectable effect on the MuLV genome expression.
D000818:Animals; D002460:Cell Line; D003907:Dexamethasone / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology*; D008274:Magnesium / Q000494:pharmacology; D008325:Mammary Neoplasms, Experimental; D008324:Mammary Tumor Virus, Mouse / Q000187:drug effects*; D051379:Mice; D010452:Peptide Biosynthesis; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism
D007328:Insulin; D003907:Dexamethasone; D012194:RNA-Directed DNA Polymerase; D008274:Magnesium
Gormonal'no-zavisimaia ékspressia genoma onkovirusov v stabil'nykh kletochnykh liniiakh raka molochnykh zhelezy mysheĭ GR i RIII.