Inhibition of RBM23 induces ferroptosis in colon cancer cells via c-Myc regulation.

BACKGROUND: RNA binding motif protein 23 (RBM23) is a member of the RNA binding motif gene family, functioning as a transcriptional cofactor and pre-mRNA splicing factor. While RBM23 is known to activate the NF-κB pathway in hepatocellular carcinoma, its role in other cancers remains unclear. In this study, we report for the first time that RBM23 inhibition induces ferroptosis via c-Myc regulation in colon cancer cells. METHODS: RBM23 overexpression in CRC was assessed using qRT-PCR and Western blotting. Functional assays, including CCK-8 and colony formation, were conducted to examine cell viability. To investigate the regulatory role of RBM23 in c-Myc expression, siRNA knockdown was followed by nuclear fractionation, cycloheximide chase, and serum stimulation assays. Immunofluorescence confirmed subcellular localization. RBM23’s role in glucose metabolism was analyzed through qRT-PCR, Western blotting, and glucose uptake assays. Oxidative stress and ferroptosis were evaluated using C11-BODIPY, DCFH-DA staining, and Western blotting. Bioinformatic analyses supported experimental data. RESULTS: RBM23 knockdown significantly reduced c-Myc protein levels and stability. This led to decreased expression of glycolytic enzymes and impaired glucose uptake. As a result, metabolic suppression triggered oxidative stress, which was further amplified by c-Myc deficiency. Elevated ROS levels regulated the expression of ferroptosis-related factors such as GPX4 and KEAP1, leading to ferroptotic cell death. These findings suggest that RBM23 maintains metabolic homeostasis and cell survival through c-Myc stabilization. CONCLUSIONS: RBM23 inhibits ferroptosis in CRC cells by regulating c-Myc-mediated metabolic pathways. Our findings suggest that RBM23 serves as a potential biomarker and therapeutic target in colorectal cancer.