RT-PCR profiling analysis of microRNA expression in cisplatin-resistant cancer

Chemotherapy remains the primary treatment of advanced solid cancer, including lung cancer. As first line treatment, cisplatin-based therapy is restricted by frequent development of drug resistance. Increasing data showed that programmed cell death protein ligand 1 (PD-L1) plays a vital role in regulating cisplatin resistance. However, the mechanisms underlying are not fully understood. We found miR-526b-3p expression declined while PD-L1 elevated in cisplatin-resistant lung cancer compared to that in cisplatin-sensitive lung cancer by analyzing clinical samples. Importantly, miR-526b-3p was associated with response to cisplatin negatively. We further demonstrated that miR-526b-3p reversed cisplatin resistance, suppressed metastasis, and activated CD8+ T cells in a STAT3/PD-L1-dependent manner. Our findings extended the knowledge of PD-L1-mediated cisplatin resistance of lung cancer. In addition, the introduction of miR-526b-3p provided a new clue to improve the anti-tumor effects of the combination of immunotherapy and chemotherapy. miProfileTM Cancer miRNA qPCR Array Three primary patients with primary cancer were recruited in the present study. MicroRNA expression profiles were obtained.