Estrogen activates mitogen-activated protein kinase in native, nontransfected CHO-K1, COS-7, and RAT2 fibroblast cell lines.

摘要: CHO-K1, COS-7, and Rat2 fibroblast cell lines are generally believed to be devoid of estrogen receptors (ERs) have been widely used study the functions ER-α ER-β after transfection their cDNAs. Numerous studies demonstrated that transfected or mediates estradiol-induced activation multiple signaling pathways, including MAPK/ERK pathways. We report here for first time both 17α-estradiol 17β-estradiol elicit in native, nontransfected lines. further that, contrary held belief, these not unresponsive estradiol state, this responsiveness is associated with binding. Using ER antibodies, we failed find isoforms even ER-X. In view findings, researchers, using such cells as models investigate mechanisms action, must always take into account exi...