MicroRNA-134 inhibits tumor stem cell migration and invasion in oral squamous cell carcinomas via downregulation of PI3K-Akt signaling pathway by inhibiting LAMC2 expression

Article type: Research Article

Authors: Zhou, Yong-Mei^{a; b; c; 1} | Yao, Yi-Lin^{b; c; 1} | Liu, Wei^{c; d} | Shen, Xue-Min^{b; c} | Shi, Lin-Jun^{b; c} | Wu, Lan^{b; c; *}

Affiliations: [a] Department of Stomatology, Hainan West Central Hospital (Shanghai Ninth People’s Hospital, Hainan Branch), Danzhou, Hainan, China | [b] Department of Oral Mucosal Diseases, Shanghai Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China | [c] National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Shanghai, China | [d] Department of Oral and Maxillofacial-Head and Neck Oncology, Shanghai Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, China

Correspondence: [*] Corresponding author: Lan Wu, Department of Oral Mucosal Diseases, Shanghai Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, No. 639, Zhizaoju Road, Huangpu, Shanghai, 200011, China. Tel.: +86 21 23271699; E-mail: [email protected].

Note: [1] These authors contributed equally to this work.

Abstract: BACKGROUND: Oral squamous cell carcinoma (OSCC) is the most common malignant neoplasm of the mouth. Some studies have found that multiple microRNAs (miRs) participate in OSCC physiological and pathological processes. METHODS: We explored the mechanism of action of miR-134 in OSCC involving the PI3K-Akt signaling pathway. Different bioinformatics methods were used to analyze the potential genes and their related miRs in OSCC. Tumor stem cells were separated from OSCCs through magnetic cell sorting. Regulatory pattern between miR-134 and LAMC2 in OSCC was evaluated by ectopic expression, knockdown and reporter assay experiments. The expression of miR-134, LAMC2, genes in PI3K-Akt signaling pathway, and apoptosis-related genes was detected. Cell proliferation was assessed by MTT assay, cell invasion by scratch test, cell migration by Transwell assay, cell cycle and apoptosis by flow cytometry, and cell growth and migration by xenograft tumor in nude mice. LAMC2 was predicted as the crucial factor related to OSCC using different chip data, and miR-134 was predicted to specifically bind LAMC2 in all five databases. RESULTS: Overexpressed miR-134 or silenced LAMC2 was observed to inhibit cell proliferation, migration, invasion of OSCC cells, growth of subcutaneous xenograft in nude mice, as well as promote OSCC cell apoptosis. LAMC2, a target gene of miR-134, decreased following miR-134 promotion, while the PI3K-Akt signaling pathway was inactivated following LAMC2 knockdown. Furthermore, we also observed that the effect of overexpressed miR-134 was enhanced when LAMC2 was knocked down. CONCLUSIONS: Taken together, these findings suggest that miR-134-mediated direct downregulation of LAMC2 inhibits migration and invasion of tumor stem cells in OSCC by suppressing the PI3K-Akt signaling pathway.

Keywords: MicroRNA-134, LAMC2, PI3K-Akt signaling pathway, oral squamous cell carcinoma, cell migration, cell invasion

DOI: 10.3233/CBM-191362

Journal: Cancer Biomarkers, vol. 29, no. 1, pp. 51-67, 2020