Circ_0002762 Regulates Oncoprotein YBX1 in Cervical Cancer via mir-375 to Regulate the Malignancy of Cancer Cells

Background: Cervical carcinoma (CC) is the third most common cancer among females and the fourth leading cause of cancer-related death, which poses a serious threat to women's health. This study investigated the biological function and mechanism of circRNA circ_0002762 in the malignant progression of CC.

Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to quantify circ_0002762, microRNA-375 (miR-375) and Y-box binding protein 1 (YBX1) mRNA expressions in CC tissues and cell lines. After circ_0002762 was overexpressed in CC cell lines, cell counting kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU) and wound healing assays were executed to probe cell growth and migration. Additionally, the targeting relationships between miR-375 and circ_0002762 or YBX1 3'-UTR were confirmed by dual-luciferase reporter assay and RNA immunoprecipitation assay. Western blot was adopted to examine YBX1 protein levels in CC cells.

Results: Circ_0002762 expression was raised in CC tissues and cell lines, and highly expressed circ_0002762 was associated with larger tumor size and lymph node metastasis of CC patients. Circ_0007262 overexpression markedly accelerated the proliferation and migration of CC cells. Besides, miR-375 was revealed to be a downstream target of circ_0002762, and miR-375 overexpression counteracted the promoting effects of circ_0002762 overexpression on CC cell viability and migration. YBX1 was identified as a target of miR-375, and circ_0002762 positively modulated YBX1 expressions through adsorbing miR-375.

Conclusion: Circ_0002762 promotes the progression of CC via sponging miR-375 and up-regulating YXB1 expression.