Exosome miR-552 Promotes Laryngocarcinoma Cells Malignant Progression via the PTEN/TOB1 Axis

Introduction: Tumor exosome-derived miRNAs play important roles in the human laryngocarcinoma. However, it is still unknown if exosome miR-552 is involved in the laryngocarcinoma. The aim of the current study was to explore exosome miR-552's role in laryngocarcinoma and its underlying mechanisms. Methods: Hep-2 exosome was characterized by transmission electron microscopy and nanoparticle tracking technology. CCK-8 was used to determine cell viability, and a xenograft animal model was used to determine the tumorigenicity. qPCR and Western blotting were used to measure the changes in target biomarkers. Luciferase reporter assay was used to evaluate the interactions between miR-552 and PTEN. miRNA sequencing was used to check the changes in miRNA profiles. Results: miR-552 was upregulated in the laryngocarcinoma patients and was positively correlated to the cell proliferation and tumor growth. PTEN was identified as a direct target of miR-552. Hep-2 exosome is featured by high expression of miR-552 and treatment of Hep-2 exosome enhanced cell proliferation and tumorigenicity. The underlying mechanisms revealed that treatment of exosomes enhanced the malignant transformation of recipient cells in part by regulating epithelial-mesenchymal transition. Conclusion: Exosome miR-552 promotes laryngocarcinoma cells' malignant progression in part by the regulation of the PTEN/TOB1 axis.