title: Effect of insulin at dilution endpoint concentrations on macromolecular synthesis in normal mouse mammary and human breast cancer epithelial cells.
abstract: Employing defined media conditions, the insulin sensitivities of mouse mammary gland epithelial cells in primary culture and MCF-7 human mammary epithelial cells were determined. Insulin stimulated the rates of (3H] uridine incorporation into RNA and [3H] leucine incorporation into protein in both primary mouse mammary gland epithelial cell cultures and MCF-7 cell cultures at concentrations approximating the dilution endpoint of the hormone (10-21 M). Insulin stimulated the rate of [3H] thymidine incorporation into DNA in primary mouse mammary gland epithelial cells at the dilution endpoint concentrations. However, MCF-7 cells required insulin concentrations 100-1000-times that necessary in mouse mammary epithelial cultures to elicit an increased rate of [3H] thymidine incorporation into DNA. Evidence is presented which suggests that the increased rates of uptake of 3H- uridine, [3H] thymidine and [3H] leucine into their respective precursor pools is not responsible for the apparent stimulation of RNA, DNA and protein synthesis.
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000378:metabolism*; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D005260:Female; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D008321:Mammary Glands, Animal / Q000378:metabolism*; D051379:Mice; D009363:Neoplasm Proteins / Q000096:biosynthesis; D014176:Protein Biosynthesis / Q000187:drug effects*; D012313:RNA / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D007328:Insulin; D009363:Neoplasm Proteins; D012334:RNA, Neoplasm; D012313:RNA