Circular RNA ciRS-7 correlates with advance disease and poor prognosis, and its down-regulation inhibits cells proliferation while induces cells apoptosis in non-small cell lung cancer.

Abstract

This study aimed to assess the association of circular RNA (circRNA) ciRS-7 expression with clinicopathological characteristics and prognosis of non-small cell lung cancer (NSCLC) patients, and to investigate its effect on cells proliferation as well as apoptosis in NSCLC. 132 patients with primary NSCLC who received surgical resection were recruited in this retrospective study. All patients' tumor tissue and paired adjacent tissue were collected for circRNA ciRS-7 expression detection by RT-qPCR. Disease-free survival (DFS) and overall survival (OS) were calculated. CCK-8 and Annexin-V/propidium iodide (AV/PI) assays were performed to detect cells proliferation and apoptosis in A549 cells after circRNA ciRS-7 inhibition plasmid transfection. CircRNA ciRS-7 expression in tumor tissue was elevated compared to paired adjacent tissue, and positively correlated with tumor size, lymph node metastasis and tumor node metastasis (TNM) stages. K-M curves illustrated that circRNA ciRS-7 high expression was correlated with both shorter DFS and OS, and multivariate Cox's proportional hazards regression analysis showed that circRNA ciRS-7 high expression was an independent factor for predicting unfavorable DFS and OS. Cells methods revealed that circRNA ciRS-7 expression was elevated in NSCLC cell lines (A549, PC9, NCI-H1299 and NCI-H1650) compared to normal lung epithelial cells (DEAS-2B), and the inhibition of circRNA ciRS-7 expression reduced cells proliferation and promoted cells apoptosis in A549 cells. CircRNA ciRS-7 overexpression is associated with advanced disease and poor prognosis in NSCLC patients, and the down-regulation of circRNA ciRS-7 inhibits tumor cells proliferation as well as improves cells apoptosis.