Histone acetyltransferase KAT6A contributes to colon cancer malignant progression by inhibiting ferroptosis.

[BACKGROUND] Colon cancer (CC) is a malignant cancer with high incidence and poor prognosis.Ferroptosis could induce iron-dependent accumulation of lipid peroxidation and oxidative death of cancer cells. This work aimed to elucidate the role of KAT6A, a lysine acetyltransferase, in CC development.

[METHODS] We collected tumor and paired non-tumor samples from patients with CC and analyzed the RNA and protein level of KAT6A using quantitative real-time PCR and immunohistochemistry (IHC) staining. We conducted KAT6A knockdown in CC cells and determined cell proliferation and ferroptosis. Cell proliferation was measured by cell counting kit-8 (CCK-8) and colony formation assay. Ferroptosis was identified by measuring the levels of lipid ROS, intracellular iron and Fe, malondialdehyde (MDA), and glutathione (GSH). The in vivo effects of KAT6A were assessed by xenograft mouse model. Protein levels of KAT6A and glutathione peroxidase 4 (GPX4) were checked by western blotting assay. The enticement of acetylation on lysine 9 of histone3 (H3K9ac) and RNA polymerase II on GPX4 gene was analyzed by chromatin immunoprecipitation (ChIP) assay.

[RESULTS] The RNA and protein level of KAT6A is notably higher in tumor tissues compared with the non-tumor sections. Depletion of KAT6A suppressed in vitro and in vivo CC cell growth. Overexpression of KAT6A reversed the erastin-induced CC cell death. knockdown of KAT6A significantly elevated the intracellular level of MDA, induced accumulation of total iron, Fe and lipid ROS, and suppressed the level of GSH. The knockdown of KAT6A caused a decrease in the expression of GPX4 and enrichment of H3K9ac on GPX4 gene.

[CONCLUSION] KAT6A promotes the proliferation of CC cells and suppresses ferroptosis via epigenetic regulation of GPX4. Our work presented KAT6A as a potential diagnostic and therapeutic target for treatment CC.