Long non-coding RNA LINC01503 predicts worse prognosis in glioma and promotes tumorigenesis and progression through activation of Wnt/β-catenin signaling.

Long-noncoding RNAs (lncRNAs) have been recently shown to be involved in the regulation of numerous biological processes including tumor progression. In this study, we aimed to explore the role of lncRNA LINC01503 (LINC01503) in the development and progression of glioma.Relative levels of LINC01503 were evaluated in tumor tissues from 133 patients with glioma as well as from cultured glioma cell lines. The correlation among LINC01503 levels, pathological types, and survivals of glioma patients were also determined using the Kaplan-Meier method and multivariate analysis. Next, we investigated the effect of LINC01503 on the proliferation, colony formation, apoptosis, migration and invasion in the U251 and LN299 cells. Relative protein expression was analyzed by Western blot assays.We found that LINC01503 expression level was significantly up-regulated in glioma tissue and cells, and that its overexpression was significantly correlated with KPS, tumor size and WHO grade in glioma patients. Kaplan-Meier analysis showed that patients with higher levels of LINC01503 had significantly poorer overall survival and disease-free survival than those with lower expression of this lncRNA in glioma patients. Multivariate analysis further confirmed that LINC01503 is an independent prognostic factor in patients with glioma. Functional assays with in vitro showed that knockdown of LINC01503 in the U251 and LN299 cell lines suppressed cells growth, colony formation, invasion and migration, and promoted apoptosis. Mechanistic investigation showed that LINC01503 can modulate Wnt/β-catenin signaling, as determined by that knockdown of LINC01503 decreased the TOP-FLASH activity and β-catenin, cyclin D1 and c-myc.Our findings suggested that LINC01503 conferred oncogenic function in glioma and may be a new prognostic biomarker and novel therapeutic strategy for this malignancy.