Objective: Perineural invasion and radioresistance are one of the main adverse features of treatment outcomes in oral squamous cell carcinoma (OSCC), but the exact mechanism is still unknown. We conducted an in vitro experiment to evaluate the role of integrin β1 (ITGB1) in the perineural invasion of radioresistant OSCC.
Methods: Two OSCC cell lines (SCC25, SCC15), radiation-induced radioresistant OSCC cell lines, and human non-neoplastic Schwann cell line (HEI-286) were used in this study. The association between expression of ITGB1 and adhesion to neural cell was evaluated using control and radioresistant OSCC cell lines. ITGB1 was inhibited by small hairpin RNA, and then the adhesion to neural cell and aggressiveness of both radioresistant OSCC cell lines were evaluated.
Result: Adhesion to neural cell was significantly increased in radioresistant cell lines than in control cell lines. In addition, the expression of ITGB1 was increased in radioresistant cell lines than in control cell lines, and ITGB1 expression was more prominent in cancer stem cell-like cells. When the expression of ITGB1 was inhibited, the adhesion to neural cell and invasion and migration of radioresistant OSCC were significantly reduced. Moreover, the expression of cancer stem cell markers and the size of spheroid formations were also significantly attenuated by inhibiting ITGB1.
Conclusion: These findings suggest that ITGB1 may be a significant contributor to the perineural invasion of radioresistant OSCC cells, and is associated with cancer stem cell-like cells. More detailed research is warranted to evaluate the role of ITGB1 as a novel emerging therapeutic target for radioresistant OSCC.