ABSTRACT
@#[Abstract] Objective: To investigate the effect and mechanism of miR-449b-5p on the proliferation of ovarian cancer cells. Methods: Cancer tissue and corresponding para-cancerous tissue specimens from 20 patients who underwent surgery in the Department of Obstetrics and Gynecology of Sichuan Provincial People's Hospital from June 2018 to June 2020 were collected for this study; in addition, normal ovarian epithelial cell line (HOSEpiC) and six human cervical cancer cell lines (SKOV3, ES-2, OVCAR-3, HO8910, CaOV-3 and A2780) were also selected. mRNA expressions of miR-449b-5p and CCNE2 in ovarian cancer tissues and cells were detected by qPCR. The plasmids miR-NC, miR-499b-5p mimic, miR-499b-5p inhibitor and pc-CCNE2 were transfected into SKOV3 cells separately or in combination. Cell growth and cell cycle were measured by the CCK-8 method and Flow cytometry, the expression of CCNE2 protein was detected by WB assay, respectively. The targeting relationship between miR-449b-5p and CCNE2 was verified by Dual luciferase reporter assay. miR-499b-5p transfected SKOV3 cells were injected subcutaneously in nude mice to construct xenograft model, and the tumor volume was measured weekly. Nude mice were sacrificed at day 42. The weight of the subcutaneous tumors was weighed by an electronic balance, and the expressions of CCNE2 and Ki67 were detected by immunohistochemistry. Results: Compared with normal ovarian tissues and epithelial cell line HOSEpiC, miR-499b expression was significantly downregulated in human cervical cancer tissues and cell lines SKOV3, ES-2, OVCAR-3, HO8910, CaOV-3 and A2780 (P<0.01). Compared with the Control group, the proliferation of SKOV3 cells in the miR-499b mimic group was significantly reduced (P<0.01) and the cell proportion in G0/G1 phase was significantly increased ( P<0.01); while the proliferation of SKOV3 cells in the miR-499b inhibitor group was significantly increased (P<0.01) and the cell proportion in G0/G1 phase was significantly reduced (P<0.01). Over-expression of miR-499b-5p significantly inhibited the luciferase activity of wild type CCNE2 plasmid (P<0.01) but had no effect on the luciferase activity of the mutant CCNE2 plasmid. Compared with the miR-499b mimic group, the growth of SKOV3 cells in the miR-499b mimic+pc-CCNE2 group was significantly increased (P<0.01) and the cell proportion in G0/G1 phase was significantly reduced (P<0.01). Compared with the miR-NC group, the tumor volume and weight of nude mice in the miR-499b mimic group were significantly reduced (all P<0.01), and the proportion of CCNE2 and Ki67 positive cells was significantly decreased (P<0.01). Conclusion: miR-449b-5p inhibits the growth and cell cycle progression of ovarian cancer cells by targeting Cyclin E2.
ABSTRACT
Objective To investigate the impact of 5-fluorouracil (5-FU) and cisplatin on miR-449b expression in human hepatocellular carcinoma (HCC) and elucidate the molecular mechanism of 5-FU and cisplatin inhibiting the migration of HCC cells.Methods Real-time qPCR analysis was conducted to determine the expression of miR-449b in 50 HCC tissues.RT-PCR assay was performed to detect the expression of miR-449b in HCC cells with 5-FU and cisplatin treatment.The migration of HCC cells with the overexpression of miR-449b was determined by wound-healing assay;Rescue assay was employed to investigate the correlation between 5-FU & cisplatin, miR-449b and the migration capacity of HCC cells;The putative targets of miR-449b were predicted and validated using target prediction programs and immunoblots.Results The expression of miR-449b decreased in HCC tissues (P<0.0001).miR-449b expression increased in HCC cells upon the treatment of 5-FU and cisplatin (P<0.001).The overexpression of miR-449b inhibited the migration of HCC cells (P<0.001).Rescue assay revealed that inhibition of miR-449b to prevent 5-FU and cisplatin induction resulted in suppressed migration in SMMC7721 cells(P<0.05).Catenin-δ was a functional target of miR-449b.Conclusions 5-FU and cisplatin inhibit the migration of HCC cells at least partly via inducing the expression of miR-449b.