m6A Modification of ATOX1 Inhibits Acute Myeloid Leukemia Progression by Promoting Cuproptosis.

[UNLABELLED] Cuproptosis, a regulated cell death caused by copper-dependent enzyme overactivation in the tricarboxylic acid cycle, leads to proteotoxic stress. Although the copper chaperone human antioxidant protein 1 (ATOX1) plays a key role in cuproptosis, its link to acute myeloid leukemia (AML) progression remains unclear. In this study, elesclomol (ES) or disulfiram (DSF)/Cu was used to induce cuproptosis, and bathocuproine disulfonic acid (BCS) was used to inhibit it. An AML xenograft mouse model was also established to validate their effects in tumor tissue. Our study demonstrated that ATOX1 is downregulated in AML. Knockdown of ATOX1 promoted cell viability and proliferation, reduced the proportion of cells in the G2-M phase, and decreased cell death. In contrast, overexpression of ATOX1 produced the opposite outcomes. Moreover, ATOX1 knockdown attenuated ES-/Cu-induced cuproptosis in AML cells, whereas ATOX1 overexpression enhanced it. This promoting effect of ATOX1 overexpression was effectively counteracted by the copper chelator BCS. Delving deeper, we discovered that ATOX1 is subject to N6-methyladenosine (m6A) modification mediated by AlkB homolog 5 (ALKBH5). Consequently, ALKBH5 can influence cuproptosis in AML cells by regulating ATOX1 expression. In vivo, the role of the ALKBH5-ATOX1 axis in AML progression has also been confirmed. In conclusion, the demethylase ALKBH5 downregulates ATOX1 by reducing its m6A levels, thereby modulating cuproptosis in AML-a mechanism that offers potential novel insights and therapeutic targets for AML treatment.

[SIGNIFICANCE] This study reveals that in AML, the demethylase ALKBH5 downregulates ATOX1 expression by reducing its m6A modification, thereby inhibiting cuproptosis and promoting AML progression. This mechanism provides a novel potential therapeutic target.