Circular RNA cir-ITCH Promotes Osteosarcoma Migration and Invasion through cir-ITCH/miR-7/EGFR Pathway

Recent studies have suggested that circular RNAs play an important role in the progression of various cancers. We aimed to investigate the possible role of cir-ITCH in osteosarcoma. In this study, we performed experiments with the human osteoblast cell line hFOB1.19 and several osteosarcoma cancer cell lines and the results showed that the expression of cir-ITCH in osteosarcoma cancer cell lines was significantly upregulated compared to that in the human osteoblast cell line. In addition, the results showed that cir-ITCH could promote the migration, invasion, and growth of osteosarcoma cells. Further mechanistic studies revealed that cir-ITCH could enhance epidermal growth factor receptor (EGFR) expression by reducing the level of miR-7. Increased EGFR phosphorylation was found to be concomitant with high expression of EGFR. We determined that cir-ITCH-mediated increase in the migration and invasion of osteosarcoma cells was dependent on EGFR phosphorylation. In conclusion, our research uncovered an important role of the cir-ITCH/miR-7/EGFR pathway in the migration and invasion of osteosarcoma cells and suggested that cir-ITCH may be a prognostic marker and a promising therapeutic target for osteosarcoma.