Abstract
PURPOSE: The incidence and mortality of breast cancer is increasing worldwide. There is a constant quest to understand the underlying molecular biology of breast cancer so as to plan better treatment options. The purpose of the current study was to characterize the expression of histone deacetylases-3 (HDAC3), a member of class I HDACs, and assess the clinical significance of HDAC3 in breast cancer. METHODS: Quantitative real-time polymerase chain reaction, immunohistochemistry, and western blot analysis were used to examine messenger RNA and protein expression levels. The relationships between HDAC3 expression and clinicopathological variables were analyzed. MTT assays were used to detect cell proliferation. Glucose-uptake, lactate, adenosine triphosphate, and lactate dehydrogenase assays were employed to detect aerobic glycolysis. Chromatin immunoprecipitation was used to detect microRNA-31 (miR-31) promoter binding. RESULTS: Our data revealed that HDAC3 was upregulated in breast cancer tissue compared with matched para-carcinoma tissues, and high levels of HDAC3 were positively correlated with advanced TNM stage and N stage of cancer. Furthermore, overexpression of HDAC3 promoted breast cancer cell-proliferation and aerobic glycolysis. The functional involvement of HDAC3 was related in part to the repression of miR-31 transcription via decreased histone H3 acetylation at lysine K9 levels of the miR-31 promoter. Survival analysis revealed that the level of HDAC3 was an independent prognostic factor for breast cancer patients. CONCLUSION: Our findings revealed that HDAC3 served as an oncogene that could promote cell proliferation and aerobic glycolysis and was predictive of a poor prognosis in breast cancer. HDAC3 participated in the cell proliferation of breast cancer, which may prove to be a pivotal epigenetic target against this devastating disease.