The Function of LINC00662/miR-340-5p/STAT3 Regulation Loop in Promoting Tumorigenesis and Development of Glioma

Abstract Background: Long noncoding RNAs( lncRNAs) have been reported to be associated with tumorigenesis and development of glioma. LINC00662 has been implicated in pathogenesis of various human cancers. However, role of LINC00662 in glioma remains unknown.Methods: Bioinformatics methods were used to analysis the expression of LINC00662 in glioma. RT-qPCR was performed to examine the expression levels of LINC00662 in glioma tissues and cell lines. The effect of LINC00662 in cell proliferation and invasion was evaluated by Cell Counting Kit-8(CCK-8), clone colony formation and transwell assay. Luciferase reporter assays were performed to investigate the interaction between miR-340-5p and LINC00662, 3’UTR of STAT3. CHIP-qPCR and Luciferase reporter assays were used to demonstrate the interaction between STAT3 and the promoter region of LINC00662. Rescue assays and Tumor xenografts in nude mice were applied to verify the effect of LINC00662 in modulating miR-340-5p/ STAT3 signal pathway.Results: LINC00662 was frequently high expressed and associated with malignant phenotype of glioma. LINC00662 knockdown inhibited proliferation, invasion and glioma-genesis of glioma. Moreover, LINC00662 knockdown repressed development of glioma by inhibiting the expression and activation of STAT3 pathway. Mechanically, LINC00662 acted as a ceRNA sponging miR-340-5p to protect the expression of STAT3. More importantly, LINC00662 was one of direct target genes of STAT3.Conclusions: There was a positive regulation loop between LINC00662 and STAT3. LINC00662 might be an oncogene in glioma. Targeting LINC00662 was a potential strategy in glioma therapy.