Long noncoding RNA EPIC1 interacts with YAP1 to regulate the cell cycle and promote the growth of pancreatic cancer cells.

Pancreatic cancer (PC) is a fatal disease; most patients are asymptomatic before the disease enters the advanced stage, but molecular mechanisms of early PC that can be exploited for diagnosis are not clear. Long noncoding RNAs (lncRNAs) play key roles in the progression of PC. In this study, we found that the expression of the lncRNA EPIC1 (Lnc-EPIC1) is high in PC and closely related to tumor size, TNM staging and lymph node metastasis status. Silencing Lnc-EPIC1 by siRNA targeting could significantly inhibit the cell growth and colony formation ability of PC cells and induced G1/S cell cycle arrest and apoptosis in PC cells. Lnc-EPIC1-specific siRNAs could downregulate the expression of cyclins and CDKs, such as CDC20, CDK4 and Cyclin A1. Knocking out YAP1 with the CRISPR/Cas-9 gene editing method recapitulated the effects of the Lnc-EPIC1-specific siRNAs on cell growth, colony formation ability and apoptosis in PC cells. In addition, the Lnc-EPIC1-specific siRNAs did not further inhibit cell growth or promote apoptosis in YAP1-knockout (YAP1-KO) cells. RNA immunoprecipitation (RIP) results showed that there was a direct interaction between Lnc-EPIC1 and YAP1. An Lnc-EPIC1-overexpressing lentiviral vector promoted the growth of PC cells. The results show that Lnc-EPIC1 interacts with YAP1 to promote the progression of PC.