EFFECT OF CIRC_0005075 ON DRUG-RESISTANT OVARIAN CANCER CELLS

Yumei Wang, Xiaoyan Liu^*, Lu Yang

Gynaecology, Weihai Central Hospital, Weihai, 264400, China

Objective: The present study aims to explore the effect of circ_0005075 on drug-resistant ovarian cancer cells and its molecular mechanism. 

Methods: A real-time fluorescent quantitative PCR (RT-qPCR) was used to detect the expression levels of circ_0005075 and miR-335 in ovarian cancer tissues, adjacent tissues, ovarian epithelial cells, ovarian cancer cell A2780 and taxolresistant cells A2780/Taxol; A2780/Taxol cells were divided into control (Con) group, si-NC group, si-circ_0005075 group, miR-NC group, miR-335 group, si-circ_0005075+anti-miR-NC group, si-circ_0005075+anti-miR-335 group. Tetramethylazolium salt colorimetric method (MTT) was used to detect cell viability; clone colony formation test was implemented to detect cell colony formation number; skin scratch test was carried out to detect cell scratch healing rate; Transwell was used to detect cell invasion number; Western blot method was used for detecting protein expression; dual-luciferase reporter experiment was conducted to detect the targeting relationship between circ_0005075 and circ_0005075. 

Results: compared to adjacent tissues and ovarian epithelial cells, the expression level of circ_0005075 in ovarian cancer tissue, ovarian cancer cell A2780 and drug-resistant cells A2780/Taxol increased, and the expression level of miR-335 decreased (P<0.05). Due to interference with circ_0005075 or overexpression of miR-335, the expression level of miR-335 in drug-resistant cells A2780/Taxol increased; cell viability was decreased; cell colony formation decreased; cell scratch healing rate decreased; the number of invasive cells decreased; E-cadherin expression increased and the expression level of N-cadherin decreased (P<0.05). Based on targeted regulation of miR-335 by circ_0005075, the inhibition of miR-335 reversed the effect of interference with circ_0005075 on the proliferation, migration and invasion of drug-resistant ovarian cancer cells. 

Conclusions: interference with circ_0005075 can inhibit the proliferation, colony formation, migration and invasion of drug-resistant ovarian cancer cells by up-regulating miR-335.