MST4 Regulates Epithelial-Mesenchymal Transition of Choriocarcinoma by Mediating TGF-β1 Expression

Hanxi Yu; Weichen Zhang; Peilin Han; Beng Yang; Xiaode Feng; Ping Zhou; Xiaoxu Zhu; Bingqian Zhou; Wei Chen; Jianhua Qian; Jun Yu

doi:10.2147/OTT.S269168

MST4 Regulates Epithelial-Mesenchymal Transition of Choriocarcinoma by Mediating TGF-β1 Expression

Onco Targets Ther. 2020 Nov 19:13:11935-11946. doi: 10.2147/OTT.S269168. eCollection 2020.

Authors

Hanxi Yu^#¹, Weichen Zhang^#², Peilin Han¹, Beng Yang², Xiaode Feng², Ping Zhou¹, Xiaoxu Zhu¹, Bingqian Zhou³, Wei Chen⁴, Jianhua Qian¹, Jun Yu²

Affiliations

¹ Department of Gynecology, The First Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou 310006, People's Republic of China.
² Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery First Affiliated Hospital, The First Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou 310006, People's Republic of China.
³ Department of Gynecology, The First Affiliated Hospital of Zhejiang University, School of Medicine, Pujiang 322200, People's Republic of China.
⁴ Department of Medical Oncology, Tongde Hospital of Zhejiang Province, Hangzhou 310012, People's Republic of China.

^# Contributed equally.

Abstract

Background: Mammalian Ste20-like kinase 4 (MST4), also known as serine/threonine kinase 26 (STK26), promotes development of several cancers and is found to be highly expressed in the placenta. However, in choriocarcinoma that originated from the placenta, the expression of MST4 was undetermined and its mechanism was unknown. In this study, the expression of MST4 in choriocarcinoma as well as the underlying mechanism was explored.

Purpose: To detect the expression of MST4 in patient samples and mechanism of mediating EMT by MST4 in choriocarcinoma.

Patients and methods: The metastatic lesions of choriocarcinoma (n=17) and volunteer villus (n=17) were collected to determine MST4 expression using immunohistochemistry and H&E staining. We use siRNA and lentiviral vector to knockdown MST4 and use plasmid to overexpress MST4 in choriocarcinoma. Then, we apply real-time polymerase chain reaction (RT-PCR), Western blot assay and immunofluorescence assay to detect target protein expressions. Cell invasion and migration and cell proliferation were detected by transwell assay and wound healing assay and CCK-8 and cell colony formation.

Results: MST4 is lowly expressed in the metastatic lesions of choriocarcinoma patients when compared with normal villus. Knockdown of MST4 activated epithelial-mesenchymal transition (EMT) process, significantly increasing the ability of invasion and migration in choriocarcinoma cell lines (JAR and JEG-3). In contrast, the EMT process was restrained in choriocarcinoma cell lines with overexpressed MST4. Meanwhile, genome-wide gene expression array, Western blot and ELISA revealed that tumor growth factor-beta 1 (TGF-β1) has significantly increased. The EMT process and metastatic prompting biofunction were reversed after using TGF-β1 inhibitor (LY364947) in the choriocarcinoma cell lines with MST4 knockdown.

Conclusion: Our studies demonstrated that MST4 was lowly expressed in patient samples. Additionally, JAR and JEG-3 increase cell invasion and migration ability while there is no influence on cell proliferation with MST4 knockdown. Conversely, the metastatic ability of JAR and JEG-3 was decreased with overexpressed MST4. Moreover, TGF-β1 was a key factor after MST4 knockdown. In conclusion, MST4 affects choriocarcinoma EMT by mediating TGF-β1 expression.

Keywords: EMT; MST4; TGF-β1; choriocarcinoma.

Grants and funding

This research was supported by 10000 people of Zhejiang Province (No. 321029-2015-0023), National Natural Science Foundation of China (81261120569 and 81370729 to JHQ) and Fundamental Research Funds for Central Universities (No. 2019QNA7030).