Biological functions of long noncoding RNAs and circular RNAs in small-cell lung cancer.

We aim to discuss comprehensively the role of long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) in small-cell lung cancer (SCLC) biology and their clinical utility as cancer biomarkers. We searched the scientific literature to select articles related to the role of lncRNAs and circRNAs in SCLC biology or as cancer biomarkers. We identified that a number of lncRNAs and circRNAs can regulate key biological processes involved in SCLC development, including cell proliferation, metastasis and chemoresistance mainly acting as miRNA sponges. Also, the expression of a few lncRNAs and circRNAs predicted survival outcome depicting their utility as prognostic biomarkers. Further investigations on the role of lncRNAs and circRNAs in SCLC tumors may yield novel therapeutic targets for SCLC.