MiR-544a Stimulates Endometrial Carcinoma Growth Via Targeted Inhibition of Reversion-inducing Cysteine-rich Protein with Kazal Motifs

Endometrial carcinoma (EC) is a female-specific malignant tumor. Although current treatments can achieve good outcomes and improve patient survival, there remains a high incidence of treatment-induced infertility, a serious side effect that is unacceptable to those of childbearing age. Studies have demonstrated that micro ribonucleic acids (microRNAs or miRNAs) such as miR-544a regulate tumor-related gene expression. However, whether miR-544a is involved in the progression of EC is unknown. This study aimed to investigate the biological functions and underlying mechanisms of miR-544a in EC in vivo and in vitro. Quantitative real-time polymerase chain reaction (qRT-PCR) revealed miR-544a overexpression in EC tissue and cell lines, which was associated with a decreased in overall survival as revealed by Kaplan-Meier analysis. Functionally, the miR-544a inhibitor restricted the proliferation [detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay], invasion, and migration (detected by transwell assay) of human endometrial adenocarcinoma cells (HEC-1B and Ishikawa) and facilitated cell apoptosis (detected by flow cytometry assay). Western blotting analysis revealed that the miR-544a inhibitor decreased the expressions of matrix metalloproteinase (MMP)-2 and MMP-9 and elevated the levels of cleaved caspase3 and cleaved poly (ADP-ribose) polymerase. Furthermore, animal experiments indicated that the miR-544a antagonist (antagomir-544a) suppressed tumor growth significantly in a mouse xenograft model. The mechanistic, qRT-PCR, and immunohistochemical indications were that a reversion-inducing cysteine-rich protein with Kazal motifs (RECK) and miR-544a had inverse expression changes in EC. Bioinformatics analysis revealed RECK as a potential target for miR-544a, and this was verified by the dual-luciferase reporter assay. Subsequently, in vitro experiments, including transwell assay, MTT assay, flow cytometry assay, and Western blotting analysis, demonstrated that RECK exerted antitumor effects on EC, which were negatively regulated by miR-544a. Taken together, our study findings suggested miR-544a as a valuable target in EC therapy.