Effect of celecoxib on protein expression of FAK and Cx43 in DMBA induced rat tongue carcinoma cells.

Abstract

The pathogenesis of tongue cancer (TA) has not been fully illustrated. Cyclooxygenase-2 (COX-2) is correlated with the precancerous lesion of oral cavity mucosa and malignant transformation. The focal adhesion kinase (FAK) and gap junction protein connexin 43 (Cx43) are involved in the occurrence and progression of tumors. This study aimed to investigate the effect of celecoxib on the proliferation, malignant transformation, and expression of FAK and Cx43 proteins. Healthy male Sprague-Dawley (SD) rats (4 months old) were divided into control, model and celecoxib group. 7,12-dimethylbenzanthracene (DMBA) was used to generate tongue mucosal carcinoma, coupled with celecoxib intervention. At 8, 12, 16, and 20 weeks after induction, the rat survival status, the tumor formation rate and the tongue tissue morphology were observed. Meanwhile, the expression of FAK and Cx43 was also evaluated by using immunohistochemistry (IHC). Tumor occurrence rates after induction were 0, 26.67%, 66.67%, and 80% at 8, 12, 16, and 20 weeks, respectively. The celecoxib treatment decreased such rats to 0, 0, 0, and 13.33%, respectively (p<0.05 compared to model group). No significant change was observed in control group, whilst model group had mild to severe hyperplasia and squamous carcinoma with elongated time. Celecoxib treatment significantly improved the tissue morphology (p<0.05). The model group also had elevated FAK and depressed Cx43 protein expression (p<0.05). With elongated time, the FAK expression was further increased whilst Cx43 protein was depressed (p<0.05 compared to model group). The focal application of celecoxib effectively inhibited the DMBA-induced rat TA, possibly via regulating FAK and CX43 protein expression, and inhibiting oral epidermal hyperplasia.