NRF1–MAP1LC3A Axis Regulates Menadione Sodium Bisulfite(MSB) Resistance in Clear Cell Renal Cell Carcinoma

AbstractBackground: Clear cell renal cell carcinoma (ccRCC) is a highly heterogeneous malignancy, and therapeutic strategies for treating drug-resistant subtypes are urgently needed. Menadione sodium bisulfite (MSB), a potential anti-cancer agent, has been shown to induce cell death in various cancer types, but its efficacy in ccRCC remains unclear.Objective: This study investigates the anti-tumor effects of MSB in ccRCC, focusing on the role of MAP1LC3A and NRF1 in regulating MSB resistance in ccRCC cells.Methods: We treated ccRCC cell lines (786-O, A498, Caki-1) with MSB and assessed cell viability using CCK-8 assays. Single-cell RNA sequencing was performed to identify different cell populations within ccRCC tumors. Western blotting, quantitative PCR, and EdU assays were conducted to evaluate protein expression and cell proliferation. The NRF1 inhibitor WRR139 was used to assess the role of NRF1 in regulating MSB resistance.Results: MSB exhibited differential anti-proliferative effects across ccRCC cell lines, with 786-O cells showing higher sensitivity to treatment. We identified MAP1LC3A as a potential marker of MSB resistance, with its expression being significantly upregulated in MSB-resistant A498 cells. NRF1 was found to regulate MAP1LC3A expression, and its inhibition sensitized A498 cells to MSB treatment.Conclusion: Our findings suggest that MAP1LC3A and NRF1 play central roles in mediating MSB resistance in ccRCC. Inhibition of NRF1 may represent a promising therapeutic strategy to enhance the anti-tumor efficacy of MSB in ccRCC treatment.