ALKBH5 decreases SLC7A11 expression by erasing m6A modification and promotes the ferroptosis of colorectal cancer cells

ABSTRACT

Background Colorectal cancer (CRC) is the major subtype of gastrointestinal malignancy and involves cancer-related genes and signaling pathways to regulate ferroptosis. The present study was conducted to analyze the role of alkB homolog 5 (ALKBH5) in the ferroptosis of CRC cells and provide novel targets for CRC treatment. Methods The transcriptional and protein levels of ALKBH5 and solute carrier family 7 members 11 (SLC7A11) in tissues and cells were determined by qRT-PCR and Western blot assay. HCT116 and SW620 cells were transfected with ALKBH5 overexpression vectors to determine cell viability and levels of reactive oxygen species (ROS), Fe+, glutathione, and glutathione peroxidase 4 using cell counting kit-8, colony formation, fluorescence probe, assay kits, and Western blot assay. The N6-methyladenosine (m6A) level and the enrichment of m6A on SLC7A11 mRNA were measured by m6A quantitative analysis and m6A methylated RNA immunoprecipitation-qPCR, and the mRNA stability was determined after actinomycin D treatment. CRC cells were treated with the combination of SLC7A11 and ALKBH5 overexpression vectors to confirm the mechanism. Nude mice were subcutaneously injected with CRC cells overexpressing ALKBH5. Results ALKBH5 was downregulated in CRC and ALKBH5 overexpression promoted ROS release and ferroptosis. ALKBH5 erased the m6A modification on SLC7A11 mRNA to reduce the mRNA stability of SLC7A11, further reducing SLC7A11 expression. SLC7A11 overexpression reversed the promotive role of ALKBH5 overexpression in ferroptosis. ALKBH5 upregulation mitigated tumor growth in vivo. Conclusions ALKBH5 reduced SLC7A11 transcription by erasing m6A modification, thus promoting the ferroptosis of CRC cells (AU)