Circular RNA CircMTO1 suppressed proliferation and metastasis of osteosarcoma through miR-630/KLF6 axis.

Abstract

Circular RNAs (circRNAs) could regulate gene expression which may induce tumor occurrence and progression. In the current study, we first investigated the expression of circMTO1 in osteosarcoma, and the underlying mechanism was further elucidated. Circular RNA microarrays were used to identify the differential expression of circRNAs in osteosarcoma tissues and the corresponding normal tissues. qRT-PCR was used to examine the level of circMTO1 in osteosarcoma tissues and cell lines. In addition, circMTO1 overexpression was constructed using lentiviral transfection in cell lines. Subsequently, the Cell Counting Kit-8 (CCK8), cell migration and invasion, and flow cytometry were used to investigate the effect of circMTO1 on the biological functions of cells. The Western Blot and the recovery experiments were used to explore the potential mechanism. Here, we measured 20 circRNAs which were downregulated in osteosarcoma tissues using circRNA microarray. CircMTO1 expression was decreased in osteosarcoma cell lines. Besides, circMTO1 could inhibit cell proliferation, migration and invasion, and induced apoptosis in osteosarcoma cells. Bioinformatics analysis showed that circMTO1 serves as a sponge for miR-630 and KLF6 is a direct target of miR-630. Furthermore, circMTO1 functions through regulation of miR-630/KLF6 axis. Our study suggests circMTO1 could suppress osteosarcoma progression by regulating miR-630/KLF6 axis, which may highlight the diagnostic and therapeutic potential of these molecules in osteosarcoma treatment.