LncRNA MELTF-AS1 facilitates osteosarcoma metastasis by modulating MMP14 expression

Abstract Osteosarcoma is a highly aggressive cancer common in children and adolescents. There is still a lack of effective treatments for metastatic or recurrent osteosarcoma. The role of lncRNAs in osteosarcoma has gradually attracted attentions. In the present study, we identified lncRNAs that were abnormally expressed in metastatic osteosarcoma through analyzing the sequencing data of osteosarcoma tissues and selected up-regulated lncRNA MELTF-AS1 for detailed study. The qPCR analysis showed that the expression of MELTF-AS1 was increased in osteosarcoma tissues and cells, and the high expression of MELTF-AS1 indicated a poor prognosis of osteosarcoma patients. The high expression of MELTF-AS1 in osteosarcoma was partly due to the transcriptional activation of RREB1. The results of transwell assays, scratch wound healing assays and the tail vein injection lung metastasis model demonstrated that knocking down MELTF-AS1 inhibited metastasis ability of osteosarcoma cells. Furthermore, the results of RNA pull down assays, luciferase reporter assays and RIP assays revealed that MELTF-AS1 could regulate MMP14 expression through interaction with miR-485-5p. Our study suggested MELTF-AS1 functioned as a pro-metastasis gene in osteosarcoma by up-regulating MMP14 and it could be a potential therapeutic and diagnostic target for osteosarcoma.