Semaphorin 4A restricts tumor progression by inhibiting angiogenesis of oral squamous cell carcinoma cells

Objective: To investigate the effects of Semaphorin 4A (Sema4A) on the angiogenesis, migration and invasion of oral squamous cell carcinoma (OSCC) cells. Methods: Sema4A expression in OSCC patients was detected by Immunohistochemistry, and its relationship with clinicopathological features and prognosis of patients was analyzed. The mRNA and protein expression of Sema4A in primary human oral keratinocytes (HOKs) and OSCC cells (SCC-25, HSC-3, CAL-27) were determined by Western blotting and qRT-PCR. After HOKs, HSC-3 cells and SCC-25 cells transfected with Control/Sema4A CRISPR activation plasmid, the migration and invasion abilities were detected by Wound healing and Transwell invasion. Tube formation assay was also performed on endothelial cells and the contents of VEGF and bFGF were quantified using qRT-PCR and ELISA. Results: Cytoplasmic Sema4A expression was related to T classification, clinical stage and nodal metastasis of OSCC patients. Patients with low cytoplasmic Sema4A expression showed the higher microvessel density (MVD) and the poorer prognosis in OSCC. Compared with HOK, OSCC cells (SCC-25, HSC-3, CAL-27) declined apparently in Sema4A expression, which was much more significant in metastatic HSC-3 and SCC-25 cells. After HOKs, HSC-3 cells and SCC-25 cells transfected with Sema4A over-expression plasmid, the invasion and migration abilities were decreased. Besides, overexpression of Sema4A could significantly inhibit the tube formation of HUVEC induced by OSCC cells with reductions of angiogenic factors (VEGF and bFGF). Conclusion: Over-expression of Sema4A could restrict tumor progression through inhibiting the angiogenesis, invasion and migration of OSCC cells.