MicroRNA-625-3p improved proliferation and involved chemotherapy resistance via targeting PTEN in high grade ovarian serous carcinoma

Abstract

Objective: High-grade serous ovarian cancer (HGSOC) is an aggressive gynaecological malignancy and associated with poor prognosis. Here we examined the effects of miR-625-3p on proliferation, treatment, migration and invasion in HGSOC.

Methods: The proliferation of HGSOC cells was evaluated by MTT assay. Transwell assay was performed to examine migration and matrigel assay were used to assess invasion. The effect of miR-625-3p on cisplatin-induced apoptosis was investigated by Caspase-Glo3/7 assay. The dual-luciferase reporter assay was carried out to confirm the potential binding site.

Results: Overexpression of miR-625-3p promoted proliferation, and increased migration and invasion in HGSOC cells. MiR-625-3p significantly inhibited cisplatin sensitivity in HGSOC cells. Meanwhile, miR-625-3p decreased cisplatin-induced apoptosis by regulation of BAX and Bcl-2 expression. Furthermore, aberrant expression of miR-625-3p changed PTEN expression by directly binding to 3'UTR of PTEN. Further study showed miR-625-3p expression was higher in human HGSOC tissue than normal ovarian tissues and associated with higher clinical stage.

Conclusions: miR-625-3p promotes HGSOC growth, involves chemotherapy resistance and might serve as a potential biomarker to predict chemotherapy response and prognosis in HGSOC.

Keywords: Apoptosis; HGSOC; PTEN; miR-625-3p.

Fig. 1

miR-625-3p expression in OVCAR3 and OVCAR4 cell after transfected either with mimic or inhibitor. A miR-625-3p expression in OVCAR3 cells transfected with miR-625-3p mimic. B miR-625-3p expression in OVCAR3 cells transfected with miR-625-3p inhibitor. C miR-625-3p expression in OVCAR4 cells transfected with miR-625-3p mimic. D miR-625-3p expression in OVCAR4 cells transfected with miR-625-3p inhibitor

Fig. 2

Forced overexpression of miR-625-3p increased growth and inhibited cisplatin sensitivity. A Growth of OVCAR3 cells forced overexpressed miR-625-3p without cisplatin. B-D Growth of OVCAR3 cells forced overexpressed miR-625-3p in presence of different doses of cisplatin (1, 2 and 4μM). E Growth of OVCAR4 cells forced overexpressed miR-625-3p without cisplatin. F-H Growth of OVCAR4 cells forced overexpressed miR-625-3p in presence of different doses of cisplatin (1, 2 and 4μM)

Fig. 3

Low level of miR-625-3p decreased growth and promoted cisplatin sensitivity. A Growth of OVCAR3 cells decreased miR-625-3p without cisplatin. B-D Growth of OVCAR3 cells decreased miR-625-3p in presence of different doses of cisplatin (1, 2 and 4μM). E Growth of OVCAR4 cells decreased miR-625-3p without cisplatin. F-H Growth of OVCAR4 cells decreased miR-625-3p in presence of different doses of cisplatin (1, 2 and 4μM)

Fig. 4

miR-625-3p inhibits cisplatin-induced apoptosis. A miR-625-3p decreased caspase 3/7 activity in OVCAR3 cells treated with cisplatin in dose dependent manner. B miR-625-3p decreased caspase 3/7 activity in OVCAR4 cells treated with cisplatin in dose dependent manner. C-D miR-625-3p regulates BAX and BCL-2 expression in OVCAR3 and OVCAR4 cells treated with cisplatin

Fig. 5

miR-625-3p regulated invasion and migration in OVCAR3 and OVCAR4 cells. A-B Forced overexpression of miR-625-3p promoted migration and invasion in OVCAR3 cells. C-D Low level miR-625-3p inhibited migration and invasion in OVCAR3 cells. E-F Forced overexpression of miR-625-3p promoted migration and invasion in OVCAR4 cells. G-H Low level miR-625-3p inhibited migration and invasion in OVCAR4 cells

Fig. 6

miR-625-3p regulated PTEN/AKT protein expression. A Forced overexpression miR-625-3p regulated expression of p-AKT, AKT and PTEN in OVCAR3 and OVCAR4 cells. B Low level of miR-625-3p regulated expression of p-AKT, AKT and PTEN in OVCAR3 and OVCAR4 cells

Fig. 7

miR-625-3p directly targeted PTEN. A The possible binding site of miR-625-3p to PTEN; B Luciferase activity of OVCAR3 cells co-transfected miR-625-3p mimic with mut-PTEN-3’-UTR-pGL3; C Luciferase activity of OVCAR3 cells co-transfected miR-625-3p mimic with wt-PTEN-3’-UTR-pGL3

Fig. 8

miR-625-3p level in human high-grade serous carcinoma tissue. A miR-625-3p level in different stage ovarian cancer. B Immunohistochemical studies for Ki-67 and PTEN on normal ovarian tissue, ovarian cancer with low level miR-625-3p and ovarian cancer with high level miR-625-3p