Introduction:
Long non-coding RNAs (lncRNAs) have been shown to have great importance in cancer development and progression. However, the mechanism of lncRNAs in epithelial ovarian cancer remains unclear. In the present study, we aimed to explore the role of the lncRNA myocardial infarction-associated transcript (MIAT) in epithelial ovarian cancer tumorigenesis.

Material and methods:
Quantitative real-time PCR (qRT-PCR) was used to determine MIAT expression in human epithelial ovarian cancer tissues and cell lines, and the effects of MIAT on cell proliferation and cell apoptosis were determined by CCK-8 assay or flow cytometry analysis. Dual-Luciferase Reporter assay and Western blot assay were used to explore the molecular mechanisms of MIAT in epithelial ovarian cancer cells progression.

Results:
Our data showed that the expression of lncRNA MIAT was remarkably increased in human epithelial ovarian cancer tissues and cell lines (p < 0.05). High MIAT expression was associated with poor overall survival of epithelial ovarian cancer patients (p < 0.05). Function assays showed that knockdown of MIAT expression significantly inhibited epithelial ovarian cancer cell proliferation and promoted cell apoptosis in vitro (p < 0.05). Moreover, we revealed that MIAT might function as an endogenous miR-330-5p sponge to regulate the target gene of miR-330-5p in epithelial ovarian cancer progression.

Conclusions:
LncRNA MIAT was found to be a tumor oncogenic lncRNA in epithelial ovarian cancer tumorigenesis. LncRNA MIAT promoted cell proliferation and inhibited cell apoptosis by negative regulation of miR-330-5p in epithelial ovarian cancer cells. Our findings suggested that MIAT might act as a candidate prognostic biomarker and new therapeutic target for treating epithelial ovarian cancer patients.