BMAL1 Drives Cisplatin Resistance in Non-Small Cell Lung Cancer Via Lactate-MRP1 Signaling Pathway.

Lung cancer, the leading cause of cancer-related mortality, faces significant therapeutic challenges due to chemoresistance. While metabolic reprogramming and circadian disruptions are implicated in tumor progression, their interplay in driving resistance remains unclear. This study identifies BMAL1, a core circadian regulator, as a key driver and potential initiator of cisplatin resistance in non-small cell lung cancer (NSCLC) through metabolic and oxidative stress pathways. We demonstrate that BMAL1 upregulates multidrug resistance protein MRP1 via HIF-1α-driven glycolysis, amplifying lactate production. Lactate activates the TAZ/c-Jun/Snail complex to increase MRP1 expression, establishing a feedforward loop that sustains chemoresistance. Furthermore, cisplatin and etoposide induce BMAL1 expression through AKT signaling in response to oxidative stress, creating a self-reinforcing resistance mechanism. Critically, targeting AKT or MRP1 reverses BMAL1-mediated resistance. These findings reveal BMAL1 as a metabolic orchestrator linking circadian dysfunction to chemoresistance and propose actionable strategies-such as AKT inhibition or chronotherapy-to circumvent therapeutic failure. This work underscores the necessity of targeting circadian-metabolic crosstalk to improve outcomes in NSCLC.