title: Steroid metabolism and binding activity in a murine renal tumor cell line.
abstract: The purpose of this study was to partially characterize the steroid binding activity of murine renal tumor cells in continuous culture. The steroid receptor content of a cloned renal tumor cell line (RAG) and a subline RAG-2 was examined by sucrose gradient analysis, hydroxylapatite and dextran-coated charcoal methods. The RAG cells lacked estrogen- and progestin-binding activity, whereas specific 5 alpha-dihydrotestosterone (DHT) and dexamethasone (Dx) binding activities were detected as 8S peaks on low salt gradients. The specificity of DHT binding was examined by sucrose gradient analysis: DHT, R1881 and ORG2058 all completely inhibited [3H]DHT binding whereas diethylstilbestrol and Dx were ineffective. The androgen receptor content of the RAG cells was approx. 15 fmol/mg cytosol protein by the hydroxylapatite-filter assay, with an estimated Kd for methyltrienolone (R1881) of 5 nM at 0 degrees C. Scatchard analysis of [3H]Dx binding by RAG cytosol showed a Kd of 6 nM for Dx and 44 nM for corticosterone at 0 degrees C. Glucocorticoid receptor levels were estimated to be 182 fmol/mg cytosol protein by dextran-coated charcoal assay. Metabolism of [3H]testosterone and [3H]DHT by RAG cells was examined 1, 4 and 6 h after exposure to labeled hormone. Radioactive DHT was the primary intracellular metabolite recovered after exposure to [3H]testosterone. There was little conversion of DHT to androstanediol.
mesh_terms: D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D003907:Dexamethasone / Q000378:metabolism; D004054:Diethylstilbestrol / Q000378:metabolism; D013196:Dihydrotestosterone / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004958:Estradiol / Q000378:metabolism; D004963:Estrenes / Q000378:metabolism; D007680:Kidney Neoplasms / Q000378:metabolism*; D015741:Metribolone; D051379:Mice; D011282:Pregnenediones / Q000378:metabolism; D013256:Steroids / Q000378:metabolism*
chemical_list: D004963:Estrenes; D011282:Pregnenediones; D013256:Steroids; D013196:Dihydrotestosterone; C020175:16 alpha-ethyl-21-hydroxy-19-nor-4-pregnene-3,20-dione; D015741:Metribolone; D004958:Estradiol; D004054:Diethylstilbestrol; D003907:Dexamethasone