Talin1 Induces Epithelial-Mesenchymal Transition to Facilitate Endometrial Cell Migration and Invasion in Adenomyosis Under the Regulation of microRNA-145-5p

Adenomyosis (ADS) is a commonly encountered benign gynecological disorder. Epithelial-mesenchymal transition (EMT) may serve a pivotal role in the pathogenesis of ADS. Talin1 has been identified to be implicated in multiple human carcinomas, probably through inducing EMT process. However, available data on the precise molecular mechanism of Talin1 in the pathogenesis of ADS remain extremely scanty. In the present study, we aim to investigate the clinical roles of Talin1 and its effects on uterine endometrial cell migration, invasion, and EMT in ADS. Relative mRNA expression of Talin1, microRNA-145-5p (miR-145-5p), and EMT-related markers was determined by qRT-PCR. Immunohistochemistry and immunofluorescence were performed to examine the distribution of Talin1 in ADS endometrium. Protein levels of Talin1, EMT-related markers, and wnt/beta-catenin pathway were measured by western blot. Wound healing assay and transwell assay were utilized for evaluating cell migration and invasion respectively. Dual-luciferase reporter assay was performed to verify the relationship between Talin1 and miR-145-5p. We found Talin1 was markedly overexpressed in ADS endometrial tissue and cells, whereas miR-145-5p was downregulated. Elevated Talin1 mRNA level might be closely related to some clinicopathological features of ADS. Through functional experiments, we demonstrated that overexpression of Talin1 induced EMT and enhanced migration and invasion ability of ADS eutopic and ectopic endometrial epithelial cells (ADS_Eu_EEC and ADS_Ec_EEC) in vitro through activating the canonical wnt/beta-catenin pathway. From a mechanistic perspective, Talin1 was inversely regulated by miR-145-5p as a direct target. Our findings unveiled that under the regulation of miR-145-5p, Talin1 might promote endometrial cell migration and invasion through inducing EMT, presenting a novel insight for elucidating the pathogenesis of ADS.