CEBPB dampens the cuproptosis sensitivity of colorectal cancer cells by facilitating the PI3K/AKT/mTOR signaling pathway

Abstract Background: Cuproptosis is a novel pathway that differs from other forms of cell death and has been confirmed to be applicable for predicting tumor prognosis and clinical treatment response. However, the mechanism underlying the resistance of colorectal cancer (CRC) to cuproptosis at the molecular level has not been elucidated. Methods: Using bioinformatics analysis, the expression of CCAAT/enhancer-binding protein beta (CEBPB) in CRC tissues and its enrichment in biological processes were detected. Quantitative reverse transcription polymerase chain reaction and western blotting (WB) were employed to test the expression of CEBPB in CRC cells. WB was utilized to assess the levels of proteins related to cuproptosis and the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway. The MTT assay was used to test cell viability. Cell proliferation was assessed by a colony formation assay. Transwell assays were used to measure cell migration and invasion ability. DLAT-aggregate formation was determined by immunofluorescence. Results: CEBPB was highly upregulated in CRC cells to enhance cell viability, proliferation, migration, and invasion. CEBPB was strongly implicated in copper ion homeostasis and the mTOR signaling pathway in CRC. In a CRC cuproptosis cell model, rescue experiments revealed that a PI3K/AKT/mTOR pathway inhibitor attenuated the promoting effect of CEBPB overexpression on the PI3K/AKT/mTOR pathway and rescued the sensitivity of CRC to cuproptosis. Conclusion: This work demonstrated that CEBPB can activate the PI3K/AKT/mTOR signaling pathway, thereby decreasing the sensitivity of CRC to cuproptosis. These data suggested that targeting CEBPB or the PI3K/AKT/mTOR pathway may enhance the sensitivity of CRC patients to cuproptosis, providing a combined therapeutic strategy for cuproptosis-induced therapy.