CircHIPK3 modulates VEGF through MiR-7 to affect ovarian cancer cell proliferation and apoptosis.

Purpose: The purpose of this study was to observe the effects of circHIPK3on the proliferation and apoptosis of ovarian cancer cells, and to further explore the potential mechanism therein.

Methods: CircHIPK3 was determined in the carcinoma tissues, normal adjacent tissues, and also in ovarian cancer cells via RT-PCR. The proliferation and apoptosis of cells were observed via colony-forming assay, 5-ethynyl-2'-deoxyuridine (EdU) staining and Western blotting. Moreover, the effect of the inhibition of circHIPK3 on the in vivo growth of ovarian cancer cells was detected using subcutaneous tumorigenesis assay. Finally, the effect of circHIPK3 on the expression of the micro ribonucleic acid (miR)-7/vascular endothelial growth factor (VEGF) signaling pathway in ovarian cancer cells was examined.

Results: CircHIPK3 in the carcinoma tissues was obviously higher than that in normal adjacent tissues. SKOV3 cell lines transfected with circHIPK3 inhibitor exhibited declined number of colonies. The inhibition of circHIPK3 distinctly suppressed the expression of B-cell lymphoma 2 (Bcl-2) and raised that of Bcl-2 associated X protein (Bax). Besides, the inhibition of circHIPK3 obviously weakened the tumorigenicity of ovarian cancer cells subcutaneously transplanted. Finally, it was found that miR-7 declined obviously and VEGF rose distinctly in the carcinoma tissues, and the in vitro assay verified the obvious increase in the expression of miR-7 and the prominently inhibited VEGF protein expression in the ovarian cancer cells with the inhibition of circHIPK3.

Conclusions: CircHIPK3 has an obviously increased expression level in the carcinoma tissues of ovarian cancer patients, and the inhibition of circHIPK3 can activate the miR-7-mediated decline in the expression of VEGF to repress the proliferation and promote the apoptosis of ovarian cancer cells.