The role of alternative polyadenylation in Epithelial-mesenchymal transition of non-small cell lung cancer

Abstract

The metastatic non-small cell lung cancer (NSCLC) is one of the cancers with high incidence, poor survival, and limited treatment. Epithelial-mesenchymal transition (EMT) is the first step by which an early tumor converts to an invasive one. Studying the underlying mechanisms of EMT can help the understanding of cancer metastasis and improve the treatment. In this study, 1,013 NSCLC patients and 123 NSCLC cell lines are deeply analyzed for the potential roles of alternative polyadenylation (APA) in the EMT process. A trend of shorter 3’-UTRs is discovered in the mesenchymal samples. The identification of EMT-related APA events highlights the proximal poly(A) selection ofCARM1. It is a pathological biomarker of mesenchymal tumor and cancer metastasis through losing miRNA binding to upregulate the EMT inducer ofCARM1and releasing miRNAs to downregulate the EMT inhibitor ofRBM47. The crucial role of this APA event in EMT also guides its effect on drug responses. The patients with shorter 3’-UTR ofCARM1are more benefit from chemotherapy drugs, especially cisplatin. A stratification of NSCLC patients based on this APA event is useful for chemotherapy design in future clinics.