Circular RNA-ITCH Suppresses Lung Cancer Proliferation via Inhibiting the Wnt/β-Catenin Pathway

Abstract

As a special form of noncoding RNAs, circular RNAs (circRNAs) played important roles in regulating cancer progression mainly by functioning as miRNA sponge. While the function of circular RNA-ITCH (cir-ITCH) in lung cancer is still less reported, in this study, we firstly detected the expression ofcir-ITCHin tumor tissues and paired adjacent noncancer tissues of 78 patients with lung cancer using a TaqMan-based quantitative real-time PCR (qRT-PCR). The results showed that the expression ofcir-ITCHwas significantly decreased in lung cancer tissues. In cellular studies,cir-ITCHwas also enhanced in different lung cancer cell lines, A549 and NIC-H460. Ectopic expression ofcir-ITCHmarkedly elevated its parental cancer-suppressive gene, ITCH, expression and inhibited proliferation of lung cancer cells. Molecular analysis further revealed thatcir-ITCHacted as sponge of oncogenic miR-7 and miR-214 to enhance ITCH expression and thus suppressed the activation of Wnt/β-catenin signaling. Altogether, our results suggested thatcir-ITCHmay play an inhibitory role in lung cancer progression by enhancing its parental gene, ITCH, expression.