Objective To explore the expression of LncRNA KCNQ1 overlapping transcript 1 (KCNQ1OT1) in ovarian cancer tissues and its relationship with clinicopathological features.

Methods The expression levels of LncRNA KCNQ1OT1 in ovarian cancer tissues, adjacent normal tissues and ovarian cancer cell lines were assessed by quantitative real-time PCR.Then, the associations of LncRNA KCNQ1OT1 expression levels with clinicopathological features and prognosis were evaluated. In addition, LncRNA KCNQ1OT1 functions in tumor progression and invasion were further determined by siRNA-induced LncRNA KCNQ1OT1 silencing in vitro.

Results The expression levels of LncRNA KCNQ1OT1 in ovarian cancer tissues and cell lines were significantly higher than those in adjacent non-tumor tissues and normal ovarian epithelial cells. Higher LncRNA KCNQ1OT1 expression levels were associated with a shorter overall survival (P=0.006) and disease-free survival (P=0.001) in ovarian cancer patients. In addition, LncRNA KCNQ1OT1 expression was positively correlated with FIGO stage (P=0.002), tumor grade (P=0.006) and distant metastasis (P < 0.001). Moreover, LncRNA KCNQ1OT1 knockdown in ovarian cancer cells markedly suppressed cell proliferation and invasion.

Conclusion The LncRNA KCNQ1OT1 is a novel factor involved in ovarian cancer progression, and constitutes a potential prognostic biomarker and therapeutic target for the patients with ovarian cancer.