LINC-PINT suppresses tumour cell proliferation, migration and invasion through targeting miR-374a-5p in ovarian cancer.

LncRNA LINC-PINT acts as an important regulator in the development of many cancers. The current study aimed to explore the role of LINC-PINT in the progression of ovarian cancer (OC). LINC-PINT expression level in different FIGO stages of OC and its adjacent tissues, normal HOSE and OC cell lines (A2780, SKOV3, OVCAR3 and HO-8910) was determined by qRT-PCR. Survival analysis on LINC-PINT and OC patients was conducted by Kaplan-Meier. CCK-8, flow cytometry, wound-healing, Transwell assays and western blot were performed to detect the effects of LINC-PINT on proliferation, apoptosis, migration, invasion and EMT process in OC cells. Target gene of LINC-PINT was predicted by Starbase and verified by dual-luciferase reporter assay. The expression of miR-374a-5p in normal and OC tissues, LINC-PINT- or siLINC-PINT-modified OC cells was determined. Moreover, rescue assay was carried out to confirm whether LINC-PINT contributes to the development of OC cells through targeting miR-374a-5p. Low expression of LINC-PINT was observed in OC tissues and cells, noticeably, LINC-PINT expression was even lower in OC tissues with higher FIGO stage. Increased LINC-PINT expression significantly inhibited cell proliferation, promoted apoptosis and suppressed migration, invasion and EMT process, while silencing of LINC-PINT caused the opposite results. Moreover, LINC-PINT sponged miR-374a-5p and overexpressed miR-374a-5p attenuated the effect of up-regulated LINC-PINT on cell viability, migration, invasion and apoptosis. LINC-PINT acts as a tumour suppressor, as it could inhibit cell proliferation, migration, invasion and EMT process, and promote cell apoptosis through down-regulating miR-374a-5p. SIGNIFICANCE OF THE STUDY: Ovarian cancer (OC), which is a frequently diagnosed tumour in female reproductive organs, has a high incidence rate behind cervical cancer and endometrial cancer. LncRNA LINC-PINT acts as an important regulator in the development of many cancers. The current study aimed to explore the role of LINC-PINT in the progression of ovarian cancer (OC) and found that LINC-PINT inhibited cell proliferation, migration invasion and EMT process of OC cell via regulating miR-374a-5p; it might be a potential target for OC treatment.