Affiliation:
1. Department of Obstetrics and Gynecology, University of British Columbia, Vancouver, British Columbia, Canada V6H 3V5
Abstract
GnRH-II is a potent GnRH subtype involved in modulating OVCAR-3 cell proliferation and the invasive properties of JEG-3 cells, and an atypical cAMP-response element (CRE) in the human GnRH-II promoter influences its activation. We demonstrated that the GnRH-II promoter is activated by 8-bromoadenosine-cAMP in several cell lines including αT3, TE671, JEG-3, and OVCAR-3 cells and that cAMP enhances GnRH-II mRNA levels in JEG-3 and OVCAR-3 cells. Moreover, 8-bromoadenosine-cAMP increases cAMP response element-binding protein (CREB) phosphorylation in JEG-3 and OVCAR-3 cells and augments CBP and CCAAT/enhancer-binding protein (C/EBP)-β coimmunoprecipitation with phosphorylated CREB (p-CREB) in a temporally defined manner from nuclear extracts. When CREB, CBP, and C/EBPβ levels were knocked down by small interfering RNA, reductions in any of these transcription factors reduced cAMP-enhanced GnRH-II promoter activity and GnRH-II mRNA levels in JEG-3 and OVCAR-3 cells. Importantly, chromatin immunoprecipitation assay showed that p-CREB bound the CRE within the endogenous GnRH-II promoter within 1 h and that p-CREB association with C/EBPβ occurs within 2 h of cAMP stimulation, coincident with the first appearance of C/EBPβ at the CRE. By contrast, maximum interactions between p-CREB and CBP do not occur until at least 4 h after cAMP stimulation, and this is reflected in the progressive loading of CBP at the CRE at 2–4 h, as demonstrated by chromatin immunoprecipitation. Taken together, these data suggest that p-CREB, C/EBPβ, and CBP are recruited to the CRE of the GnRH-II promoter in a temporarily defined manner to enhance its transcription in JEG-3 and OVCAR-3 cells in response to cAMP.
Cited by
9 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
1. Role of gonadotropin-releasing hormone 2 and its receptor in human reproductive cancers;Frontiers in Endocrinology;2024-01-08
2. The cAMP Analogue, dbcAMP, Affects Rabbit Ovarian Cell Proliferation, Apoptosis, Release of Steroids and Response to Hormones;Folia Biologica;2014-07-31
3. Importance of C/EBPβ Binding and Histone Acetylation Status in the Promoter Regions for Induction of IGFBP-1, PRL, and Mn-SOD by cAMP in Human Endometrial Stromal Cells;Endocrinology;2014-01-01
4. Short Communication The Effect of the cAMP Analogue, dbcAMP, on Proliferation and Apoptosis of Rabbit Oviductal Cells;Folia Biologica;2013-08-30
5. The camp analogue, dbcAMP can stimulate rabbit reproductive functions: I. Effect on ovarian folliculogenesis, ovulation and embryo production;Acta veterinaria;2012