USP13 serves as a tumor suppressor via the PTEN/AKT pathway in oral squamous cell carcinoma

BACKGROUND: : Recent studies have shown that USP13 a deubiquitinase, serves as an important regulator of tumorigenesis. However, the biological role of USP13 in oral squamous cell carcinoma (OSCC) remains enigmatic. MATERIALS AND METHODS: : We examined USP13 expression in OSCC and adjacent normal tissues by immunohistochemical staining. The biological functions of USP13 in OSCC cells and the possible underlying mechanisms were investigated. RESULTS: : In this study, we showed that USP13 expression was frequently reduced in human OSCC specimens and that the reduction was correlated with the clinical stage. Functional studies demonstrated that overexpression of USP13 suppressed OSCC cell proliferation, glucose uptake and lactate production in vitro and inhibited tumor growth in vivo. Furthermore, USP13 overexpression induced phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression and repressed the activation of AKT as well as the expression of the downstream effectors glucose transporter-1 (GLUT1) and hexokinase-2 (HK2). Overexpression of PTEN reversed the USP13-knockdown-induced glucose uptake, lactate production, AKT activation, and expression of GLUT1 and HK2. CONCLUSION: : Our findings suggest that USP13 serves as a tumor suppressor by regulating the PTEN/AKT signaling pathway in OSCC cells, improving our understanding of OSCC progression and providing a clue for the development of a novel cancer therapy.