PD35-09 DIFFERENTIAL ACTIONS OF ERα AND ERβ VIA NON-GENOMIC SIGNALING IN HUMAN PROSTATE STEM-PROGENITOR CELLS
Year: 2016
Type: article
Abstract: INTRODUCTION AND OBJECTIVES: Estrogens have been implicated in prostate development and cancer; however, specific roles of estrogen receptor-a and estrogen receptor-b are not well established.Using human prostate stem-progenitor cells we have previously shown that non-genomic pathways are involved in estrogen actions.Our present study sought to elucidate specific roles for ERa and ERb via membrane initiated signaling in stem-progenitor cells.METHODS: Human prostate stem-progenitor cells were enriched from primary prostate epithelial cell culture of young, diseasefree donors using a 3D prostasphere (PS) model as previously described.Cells were labeled using ERa or ERb antibodies and prostate stem cell markers CD49f and TROP2 followed by triple channel FACS to quantify ERa+/ERb+ cell numbers.To explore ERa, the benign human prostate stem cell line WPE-stem, with extremely low levels of ERa and ERb, was stably transfected with a lentiviral-ERa expression vector.The human prostate cancer stem-like cell line HuSLC (ERb++, ERa-) was used to interrogate ERb actions.Cells were exposed to 10 nM estradiol (E2) over a 15 to 60 minute time course +/-ICI 182,870 (ICI), an ERa/b antagonist.Western Blotting was used to quantify phosphorylation of target proteins.RESULTS: FACS analysis of day 7 PS cells labeled for ERa or ERb revealed 66% of day 7 PS cells as ERa+ and 40% as ERb+.Among ERa or ERb positive PS cells, 4% were Trop2+/CD49f high (stem-like cells) and 10-12% were Trop2+/CD49f medium (early stage progenitor cells).PS exposed to 10 nM E2 showed sequential phosphorylation of Src, Erk1/2, p38, Akt and NFkB (p65) over 60 minutes.ICI attenuated Akt and Erk1/2 phosphorylation, confirming membrane bound ERs are involved in downstream signaling.E2 treatment of HuSLCs showed phosphorylation of Erk1/2 but not Akt, indicating that ERb signals exclusively through the MAPK pathway in these cells.Conversely, E2 treatment of WPE-stem cells overexpressing ERa resulted in robust phosphorylation of Akt but lower levels of Erk1/2 phosphorylation suggesting that Akt activation may be more reliant on ERa signaling.CONCLUSIONS: ERs trigger cellular responses via activation of signaling cascades that originate at the membrane (non-genomic signaling) in addition to nuclear signaling.The present findings reveal that human prostate stem-progenitor cells express both ERa and ERb, which differentially activate membrane signaling cascades.This may lead to unique downstream actions that influence prostate stem-progenitor cell proliferation as well as lineage commitment decisions.
Source: The Journal of Urology
Authors: Shyama Majumdar, Neha Malhotra, Susan Kasper, Lishi Xie, Timothy Gauntner, Wen-yang Hu, Gail Prins
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2315200026