HDAC3-ER? Selectively Regulates TNF-?-Induced Apoptotic Cell Death in MCF-7 Human Breast Cancer Cells via the p53 Signaling Pathway.

ABSTRACT: Tumor necrosis factor-? (TNF-?) plays a significant role in inflammation and cancer-related apoptosis. We identified a TNF-?-mediated epigenetic mechanism of apoptotic cell death regulation in estrogen receptor-? (ER?)-positive human breast cancer cells. To assess the apoptotic effect of TNF-?, annexin V/ propidium iodide (PI) double staining, cell viability assays, and Western blotting were performed. To elucidate this mechanism, histone deacetylase (HDAC) activity assay and immunoprecipitation (IP) were conducted; the mechanism was subsequently confirmed through chromatin IP (ChIP) assays. Finally, we assessed HDAC3-ER?-mediated apoptotic cell death after TNF-? treatment in ER?-positive human breast cancer (MCF-7) cells via the transcriptional activation of p53 target genes using luciferase assay and quantitative reverse transcription PCR. The TNF-?-induced selective apoptosis in MCF-7 cells was negatively regulated by the HDAC3-ER? complex in a caspase-7-dependent manner. HDAC3 possessed a p53-binding element, thus suppressing the transcriptional activity of its target genes. In contrast, MCF-7 cell treatment with TNF-? led to dissociation of the HDAC3-ER? complex and substitution of the occupancy on the promoter by the p53-p300 complex, thus accelerating p53 target gene expression. In this process, p53 stabilization was accompanied by its acetylation. This study showed that p53-mediated apoptosis in ER?-positive human breast cancer cells was negatively regulated by HDAC3-ER? in a caspase-7-dependent manner. Therefore, these proteins have potential application in therapeutic strategies.

SUBMITTER: Park SH 

PROVIDER: S-EPMC7290399 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature