The Potential Role of Nrf2-PD-L1 Axis in Promoting of Oxaliplatin Resistance in Colon Cancer Cells

Background: Nuclear factor−erythroid 2−related factor 2 (Nrf2) has a key function in promoting chemoresistance in various cancers. PD-L1 is one of the downstream targets of Nrf2 signaling pathway, having some beneficial impacts on tumors growth by inhibition of the immune system. The aim of this study was to investigate the potential role of Nrf2- PD- L1 axis in the promotion of oxaliplatin resistance in colon cancer cells. Result: Our data revealed that Nrf2 and PD-L1 mRNA expressions were markedly higher in tumor tissues compared to margin tissues. PD-L1 mRNA expression level was also increased in the resistant cells. However, Nrf2 expression was decreased and increased in SW480/Res and LS174T/Res cells, respectively. Nrf2 inhibition through siRNA in SW480/Res and LS174T/Res decreased the IC50 values of oxaliplatin. Inhibition of Nrf2 significantly increased oxaliplatin-induced apoptosis and reduced migration in SW480/Res cells when accompanied with oxaliplatin. Conclusion: Our study suggests that effective inhibition of Nrf2/PD-L1 signaling pathways can be considered as a novel approach to improve oxaliplatin efficacy in colon cancer patients.