Promoting action of long non-coding RNA small nucleolar RNA host gene 4 in ovarian cancer.

Objective: Long non-coding RNA (LncRNA) small nucleolar RNA host gene 4 (SNHG4) has been shown to be aberrantly expressed in a variety of cancers and involved in cancer development, but its role in ovarian cancer (OC) is unclear. The purpose of this study was to explore the biological function of SNHG4 in OC and reveal its potential downstream molecular targets.

Methods: OC tumor tissue and normal tissue were collected; normal human ovarian epithelial cell line (IOSE80) and human ovarian cancer cell line (A2780, SKOV-3, OV-90 and CAOV3) were selected. RT-qPCR was used to detect SNHG4, miR-98-5p, and TMED5, while western blot was used to detect the protein expression levels of TMED5, Ki67, MMP-9, Bcl-2, Bax, Gsk3β, Wnt3a, and β-catenin. The subcellular localization of SNHG4 was assessed by nucleocytoplasmic separation assay. CCK-8, colony formation assay, flow cytometry, and Transwell were used to assess the biological behavior of OC cells. The targeting relationship between SNHG4, miR-98-5p and TMED5 was verified by dual luciferase reporter assay and RIP assay.

Results: In OC, SNHG4 and TMED5 were highly expressed, and miR-98-5p was underexpressed. Knockdown of SNHG4 inhibited OC cell proliferation, migration and invasion, promoted apoptosis, and prevented Wnt/β-catenin pathway activation. The effect of knockdown of SNHG4 was reversed by knockdown of miR-98-5p or overexpression of TMED5. Mechanistically, SNHG4 competitively adsorbed miR-98-5p to mediate TMED5 expression, thereby activating the Wnt/β-catenin pathway.

Conclusion: SNHG4 accelerates OC development via mediating the miR-98-5p/TMED5 axis and activating the Wnt/β-Catenin pathway. SNHG4 gene silencing might be a novel option for OC treatment.