Objective To investigate the effect of microRNA-214-3p(miR-214-3p)expression in cancer-associated fibroblasts(CAFs)on the cisplatin sensitivity of ovarian cancer cells and its mechanism.Methods Sixty-four ovarian cancer patients were selected as study subjects and divided into platinum-partially sensitive group and platinum-sensitive group based on progression-free survival after chemotherapy.Real-time quantitative polymerase chain reaction(qRT-PCR)was used to detect the relative expression of miR-214-3p in ovarian cancer tissues from the two groups,and the 2-year survival rates of patients with different clinical characteristics were compared.CAFs and normal ovarian fibroblasts(NFs)were primarily cultured,and qRT-PCR and immunofluorescence experiments were used to detect the expression of miR-214-3p and p62 protein in CAFs and NFs.The expression lev-els of SQSTM1 gene in different types of ovarian cells were searched through the CSIOVDB data-base.CAFs were transiently transfected with miR-214-3p mimic(mimic group)and miR-214-3p mimic NC(NC group),and untransfected CAFs were selected as control group.Cell culture super-natants from each group were collected,and an indirect co-culture model of ovarian cancer cell line SKOV3 with CAFs from each group was established.The CCK-8 method,DCFH-DA method,qRT-PCR,and immunoblotting were used to detect the proliferation rate,half-maximal inhibitory concen-tration of cisplatin(IC50),reactive oxygen species(ROS)content,and relative expression levels of miR-214-3p,cisplatin resistance gene CCND1,and autophagy protein p62 in SKOV3 cells under different culture conditions.Results The relative expression of miR-214-3p was lower in the plati-num-partially sensitive group than in the platinum-sensitive group(P＜0.01).There were statisti-cally significant differences in the 2-year survival rates among patients with different International Federation of Gynecology and Obstetrics(FIGO)stages,platinum partial sensitivity,and low miR-214-3p expression(P＜0.01).The relative expression of miR-214-3p was lower in ovarian CAFs than in NFs,while the expression level of p62 protein was higher in CAFs than in NFs(P＜0.01).Online analysis of the CSIOVDB database showed that the expression level of SQSTM1 gene in ovari-an CAFs was higher than that in ovarian cancer epithelial cells and NFs(P＜0.01).Compared with SKOV3 cells indirectly co-cultured with CAFs in the control group and CAFs in NC group,SKOV3 cells indirectly co-cultured with mimic CAFs showed reduced proliferation rate,cisplatin IC50,and ROS content,increased relative expression of miR-214-3p,and decreased relative ex-pression of CCND1 mRNA and p62 protein(P＜0.01).Conclusion The expression of miR-214-3p in CAFs is correlated with the sensitivity of ovarian cancer cells to cisplatin.Low expression of miR-214-3p in CAFs can promote the proliferation of ovarian cancer cells and ROS-mediated autophagy,thereby reducing the sensitivity of ovarian cancer cells to cisplatin.

Objective To investigate the effect of microRNA-214-3p(miR-214-3p)expression in cancer-associated fibroblasts(CAFs)on the cisplatin sensitivity of ovarian cancer cells and its mechanism.Methods Sixty-four ovarian cancer patients were selected as study subjects and divided into platinum-partially sensitive group and platinum-sensitive group based on progression-free survival after chemotherapy.Real-time quantitative polymerase chain reaction(qRT-PCR)was used to detect the relative expression of miR-214-3p in ovarian cancer tissues from the two groups,and the 2-year survival rates of patients with different clinical characteristics were compared.CAFs and normal ovarian fibroblasts(NFs)were primarily cultured,and qRT-PCR and immunofluorescence experiments were used to detect the expression of miR-214-3p and p62 protein in CAFs and NFs.The expression lev-els of SQSTM1 gene in different types of ovarian cells were searched through the CSIOVDB data-base.CAFs were transiently transfected with miR-214-3p mimic(mimic group)and miR-214-3p mimic NC(NC group),and untransfected CAFs were selected as control group.Cell culture super-natants from each group were collected,and an indirect co-culture model of ovarian cancer cell line SKOV3 with CAFs from each group was established.The CCK-8 method,DCFH-DA method,qRT-PCR,and immunoblotting were used to detect the proliferation rate,half-maximal inhibitory concen-tration of cisplatin(IC50),reactive oxygen species(ROS)content,and relative expression levels of miR-214-3p,cisplatin resistance gene CCND1,and autophagy protein p62 in SKOV3 cells under different culture conditions.Results The relative expression of miR-214-3p was lower in the plati-num-partially sensitive group than in the platinum-sensitive group(P＜0.01).There were statisti-cally significant differences in the 2-year survival rates among patients with different International Federation of Gynecology and Obstetrics(FIGO)stages,platinum partial sensitivity,and low miR-214-3p expression(P＜0.01).The relative expression of miR-214-3p was lower in ovarian CAFs than in NFs,while the expression level of p62 protein was higher in CAFs than in NFs(P＜0.01).Online analysis of the CSIOVDB database showed that the expression level of SQSTM1 gene in ovari-an CAFs was higher than that in ovarian cancer epithelial cells and NFs(P＜0.01).Compared with SKOV3 cells indirectly co-cultured with CAFs in the control group and CAFs in NC group,SKOV3 cells indirectly co-cultured with mimic CAFs showed reduced proliferation rate,cisplatin IC50,and ROS content,increased relative expression of miR-214-3p,and decreased relative ex-pression of CCND1 mRNA and p62 protein(P＜0.01).Conclusion The expression of miR-214-3p in CAFs is correlated with the sensitivity of ovarian cancer cells to cisplatin.Low expression of miR-214-3p in CAFs can promote the proliferation of ovarian cancer cells and ROS-mediated autophagy,thereby reducing the sensitivity of ovarian cancer cells to cisplatin.