Circular RNA cir-ITCHPromotes 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-ITCHin 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-ITCHin osteosarcoma cancer cell lines was significantly upregulated compared to that in the human osteoblast cell line. In addition, the results showed that cir-ITCHcould promote the migration, invasion, and growth of osteosarcoma cells. Further mechanistic studies revealed that cir-ITCHcould 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-ITCHmay be a prognostic marker and a promising therapeutic target for osteosarcoma.