The Inhibitory Effect of miR-345 on Glioma Progression Is Closely Related to circRNA-hsa_circ_0073237 and HDGF

Glioma is the most common primary malignant tumor of the central nervous system and has a poor prognosis. Therefore, exploring the key molecular targets is a new opportunity for basic research and clinical treatment of glioma. Previous studies found that circRNA-hsa_circ_0073237 was upregulated in gliomas. Our further analyses of the biological function and molecular mechanism of hsa_circ_0073237 showed that hsa_circ_0073237 was also upregulated in glioma cell lines and could combine with miR-345 to inhibit its expression. miR-345 was downregulated in glioma tissues and cells, and targeted to regulate the expression of hepatoma-derived growth factor (HDGF), while HDGF expression was enhanced in glioma. Hsa_circ_0073237 promoted the expression of HDGF in glioma cells by adsorbing miR-345. Hsa_circ_0073237 siRNA, miR-345, and HDGF siRNA effectively inhibited cell viability and invasion and promoted cell apoptosis. When expression of hsa_circ_0073237 and miR-345 was inhibited simultaneously, cell viability, apoptosis, and invasion did not change significantly; however, after transfection with HDGF overexpression vector, the effects of hsa_circ_0073237 siRNA and miR-345 on glioma cell viability, apoptosis, and invasion were obviously reversed. Further construction of glioma xenograft models in nude mice confirmed that the introduction of miR-345 in vivo effectively inhibited tumor growth, significantly reduced tumor diameter and weight, and obviously decreased the expression of HDGF. Therefore, hsa_circ_0073237 can regulate the biological functions of glioma cells through miR-345/HDGF, thereby affecting the progression of tumors, indicating that the hsa_circ_0073237/miR-345/HDGF pathway may be a key target for the treatment of glioma.