SATB2 Overexpression Promotes the Proliferation, Migration and Invasion of Oral Squamous Cell Carcinoma by Up-Regulating NOX4

Abstract

Background: While atypical expression of special AT-rich sequence-binding protein 2 (SATB2) has been approved associated with tumor progression, metastasis and unfavourable prognosis in various carcinomas. However, in oral squamous cell carcinoma (OSCC), both the expressive state and associated functions of SATB2’s are still undefined.Methods: Real-time PCR, western blotting, and immunohistochemistry were used to examine SATB2 expression. In vitro experiments including Flow Cytometry, CCK8 assay, migration assay, wound-healing assay were used to investigate the effects of SATB2 on HN4 cell proliferation, migration and invasion ability. Additionally, an orthotopic implantation assay was performed in nude mice to confirm the effects of SATB2 in vivo. Furthermore, a genome wide siRNA knockdown experiment was performed to explore the potential downstream regulatory mechanism of SATB2 in OSCC.Results: We found that , in clinical samples from a retrospective cohort of 58 OSCC patients, high expression of SATB2 is associated with poor prognosis of OSCC patients. In this study, we investigated SATB2 is highly expressed in OSCC tissues and cell lines ,which can promotes OSCC cells’ proliferation, migration, invasion and tumor growth. Following a genome wide siRNA knockdown experiment, we identified NOX4, a bona fide downstream target of SATB2, which can partially suppress OSCC proliferation. Furthermore, NOX4 knockdown inhibits tumorigenicity, which can be rescued partially by ectopic expression of SATB2.Conclusion: Our findings not only indicate overexpression of SATB2 triggers the proliferative, migratory and invasive mechanisms which are important in the malignant phenotype of OSCC, but also identify NOX4 as the downstream gene for SATB2. These findings indicate that SATB2 may play a key role in OSCC tumorigenicity and may be a future target for the development of new therapeutic regimens.