CircKDM4C upregulates P53 by sponging hsa-let-7b-5p to induce ferroptosis in acute myeloid leukemia.

To investigate the role of circKDM4C in acute myeloid leukemia (AML), the expression of circKDM4C, hsa-let-7b-5p, and P53 was measured by qRT-RCR. AML cell lines(K-562 and HL-60) were transfected correspondingly and investigated for cell proliferation, migration, and invasion abilities by CCK-8, colony formation, transwell, and wound healing assays, respectively. The levels of P53, ACSL4, PTGS2, GPX4, and FTH1 in the K-562, and HL-60 cells were measured by western blotting. Also, circKDM4C mediated regulation of ferroptosis was studied. The Phen Green SK probe and confocal laser scanning microscope were used to assess the cellular iron levels. The reactive oxygen species levels were analyzed by fluorescence-activated cell sorting using the C11-BODIPY probe. Bioinformatics analysis predicted the putative binding sites among circKDM4C, hsa-let-7b-5p, and P53. These were verified using the dual-luciferase reporter assay, RNA pull-down, and RNA immunoprecipitation assays. Finally, in vitro findings were also verified in vivo using the nude mice. CircKDM4C was significantly down-regulated in AML patients. The overexpression of circKDM4C in AML cell lines inhibited the cell proliferation, migration, invasion, and promoted ferroptosis. We found that circKDM4C acts as a sponge of hsa-let-7b-5p and thereby regulates p53 which is a target gene of hsa-let-7b-5p. Also, the expression of circKDM4C and hsa-let-7b-5p are negatively correlated, while circKDM4C and p53 are positively correlated to AML patients. Moreover, we found that circKDM4C induces ferroptosis by sponging hsa-let-7b-5p which upregulates the expression of P53. This work emphasizes the role of circKDM4C in AML patients, which could be explored for the therapeutic role.