Induction of bcl-xL expression in mammary epithelial cells is glucocorticoid-dependent but not signal transducer and activator of transcription 5-dependent.
In the present study, we examined the role of prolactin and glucocorticoids in regulating bcl-x transcription in mammary epithelial cells. We report that dexamethasone, but not prolactin, induced native bcl-x gene expression in a dose-dependent manner in HC11 cells and enhanced serum-starved HC11 cell survival. This effect was mediated through the glucocorticoid receptor and independent of STAT-5 activity. We propose that the mechanism through which glucocorticoids enhance mammary epithelial cell survival is by increasing steady-state levels of bcl-xL, RNA.
Schorr
K
K
Department of Physiology, University of Maryland Medical School, Baltimore 21201, USA.
Furth
P A
PA
D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000502:physiology*; D003907:Dexamethasone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D005938:Glucocorticoids / Q000494:pharmacology*; D006727:Hormone Antagonists / Q000494:pharmacology; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D015735:Mifepristone / Q000494:pharmacology; D008894:Milk Proteins; D011388:Prolactin / Q000494:pharmacology*; D014176:Protein Biosynthesis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis* / Q000235:genetics; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D011965:Receptors, Glucocorticoid / Q000037:antagonists & inhibitors / Q000502:physiology*; D050799:STAT5 Transcription Factor; D015534:Trans-Activators / Q000502:physiology*; D015854:Up-Regulation / Q000187:drug effects; D051020:bcl-X Protein
D004268:DNA-Binding Proteins; D005938:Glucocorticoids; D006727:Hormone Antagonists; D008894:Milk Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011965:Receptors, Glucocorticoid; D050799:STAT5 Transcription Factor; D015534:Trans-Activators; D051020:bcl-X Protein; D015735:Mifepristone; D012313:RNA; D003907:Dexamethasone; D011388:Prolactin