Negative regulation of HDAC3 transcription by histone acetyltransferase TIP60 in colon cancer.

Background: Colon cancer is the third most common cancer globally. The expression of histone deacetylase 3 (HDAC3) is upregulated, whereas the expression of tat interactive protein, 60 kDa (TIP60) is downregulated in colon cancer. However, the relationship between HDAC3 and TIP60 in colon cancer has not been clearly elucidated.

Objective: We investigated whether TIP60 could regulate the expression of HDAC3 and suppress colon cancer cell proliferation.

Methods: RNA sequencing data (GSE108834) showed that HDAC3 expression was regulated by TIP60. Subsequently, we generated TIP60-knockdown HCT116 cells and examined the expression of HDAC3 by western blotting and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). We examined the expression pattern of HDAC3 in various cancers using publicly available datasets. The promoter activity of HDAC3 was validated using a dual-luciferase assay, and transcription factors binding to HDAC3 were identified using GeneCards and Promo databases, followed by validation using chromatin immunoprecipitation-quantitative polymerase chain reaction. Cell proliferation and apoptosis were assessed using colony formation assays and fluorescence-activated cell sorting analysis of HCT116 cell lines.

Results: In response to TIP60 knockdown, the expression level and promoter activity of HDAC3 increased. Conversely, when HDAC3 was downregulated by overexpression of TIP60, proliferation of HCT116 cells was inhibited and apoptosis was promoted.

Conclusion: TIP60 plays a crucial role in the regulation of HDAC3 transcription, thereby influencing cell proliferation and apoptosis in colon cancer. Consequently, TIP60 may function as a tumor suppressor by inhibiting HDAC3 expression in colon cancer cells.