Mechanisms of drugs-resistance in small cell lung cancer

Lung cancer is the leading cause of cancer mortality and is classified by the World Health Organization into two broad histological subtypes. Non–small cell lung cancer (NSCLC), including adenocarcinoma, squamous cell carcinoma, and large cell carcinoma, accounts for ~85% of all lung cancer cases, with the remaining 15% of cases being due to small cell lung cancer (SCLC), which arises from neuroendocrine cells in the lung. Although most SCLC tumors are initially responsive to chemotherapy and radiation, patients often experience relapse, with the tumor acquiring an aggressiveness and therapeutic resistance that lead to a poor clinical outcome. Improvement of overall survival in individuals with SCLC will require the identification of novel therapeutic targets based on a better understanding of the changes in intracellular signaling of aggressive SCLC cells. The malignant progression of SCLC often occurs concomitantly with the acquisition of chemoresistance, suggesting that phenotypic malignant change is related to adaptation to the stresses induced by chemotherapy. In order to analyze gene expression changes associated with malignant transformation in SCLC, we established a cisplatin-resistant SCLC cell line and performed RNA sequencing. Overall design: Cisplatin-resistant SBC5 cells were generated by exposing the parental cell lines to stepwise increases in the concentration of cisplatin. RNAs were isolated from parental and cisplatin-resistant SBC5 cells and subjected RNA-sequencing analysis.