Progesterone Receptor-NFκB Complex Formation Is Required for Progesterone-Induced NFκB Nuclear Translocation and Binding Onto the p53 Promoter

Abstract

We previously demonstrated that progesterone (P4) up-regulates p53 expression in human umbilical venous endothelial cells (HUVECs) through P4 receptor (PR) activation of extranuclear signaling pathways. However, the involvement of nuclear PR in P4-increased p53 expression is still unclear. Here, the molecular mechanism underlying PR-regulated p53 expression in HUVECs was investigated. Treatment with P4 increased nuclear factor of κ light polypeptide gene enhancer in B-cells inhibitor, α phosphorylation (IκBα and nuclear factor-κB (NFκB) nuclear translocation. Interestingly, P4 also increased PR-A, but not PR-B, nuclear translocation in HUVECs. Immunoprecipitation assay illustrated that P4 increased the formation of PR-A-NFκB complex in both the cytosol and the nucleus of HUVEC. Chromatin immunoprecipitation assay showed an interaction between PR and the NFκB binding motif on the p53 promoter. Ablation of the NFκB binding motif in the p53 promoter completely abolished P4-increased p53 promoter activity. In the absence of P4, overexpression of NFκB did not increase NFκB nuclear translocation. In contrast, treatment of NFκB-overexpressing HUVECs with P4 for only 4 hours, which is much shorter than the time (21.5 h) required for P4-induced IκBα phosphorylation, increased NFκB nuclear translocation. Blockade of PR activity abolished this effect. Taken together, these results uncover a novel role of PR for P4-induced NFκB nuclear translocation and suggest that PR-A-NFκB complex formation is required for NFκB nuclear translocation and binding onto the p53 promoter in HUVECs. Our data indicate that both nuclear and extranuclear signaling pathways of PR are involved in P4-regulated p53 expression in HUVECs.

Enriched transcriptome analysis of laser capture microdissected populations of single cells to investigate intracellular heterogeneity in immunostained FFPE sections

“…The enrichment of elements of the NF-κB signaling pathway is consistent with previous studies suggesting a regulatory role of PR on NF-κB signaling through interaction with elements of the NF-κB pathway (e.g. p65) and co-recruitment to the promoters of target genes [45] , [46] , [47] . Moreover, the upregulated genes involved in PRRs and immune receptor signaling pathways shown by the functional clustering analysis (e.g.…”

Extranuclear signaling by sex steroid receptors and clinical implications in breast cancer

“…Limited data suggest that progesterone/PR and p53 may play a cooperative role in regulating chromosome stability [299]. Extranuclear PR signaling regulates p53 expression in human umbilical vein endothelial cells (HUVEC) [300], as progesterone treatment of HUVECs activates c-Src/Ras/Raf/MAPK/NFκB signaling to activate p53 gene transcription and control of cell cycle progression [300, 301]. Progesterone/PR also regulate p53 expression in BC, but it remains to be determined if similar mechanisms of extranuclear/nuclear PR activation of p53 occur in BCs.…”

“…This cytoskeletal reorganization associates with formation of specialized cell membrane structures such as membrane ruffles, filopodia and lamellipodia [302, 303]. Extranuclear ER/PR signaling is reportedly involved in actin remodeling and cell migration [301, 304]. E2 treatment of T47D ER+/PR+ BC cells induces rapid changes in the actin cytoskeleton with formation of membrane ruffles and pseudopodia [305].…”

Extra-Nuclear Signaling Pathway Involved in Progesterone-Induced Up-Regulations of p21cip1 and p27kip1 in Male Rat Aortic Smooth Muscle Cells

“…Ablation of the NFκB binding motif in the p53 promoter completely abolishes P4-induced increases in the p53 promoter activity. These results suggest that the PR-NFκB complex formation is required for mediating p53 expression [ 35 ]. Taken together, these findings further suggest that P4-induced up-regulations of p21 cip1 and p27 kip1 were mediated through a non-genomic action of PR.…”