Over-expression of PDE5 in Oral Squamous Cell Carcinoma – Effect of Sildenafil Citrate

Abstract

Background/Aim: Phosphodiesterase 5 (PDE5) holds clinical relevance in several pathological states, including lung, breast, and prostate cancer. In this study, we examined PDE5 expression in oral squamous cell carcinoma (OSCC)-derived cell lines and tissues, and the anti-tumour effect of PDE5 inhibitor, sildenafil citrate (SC). Materials and Methods: Cell proliferation, cell invasion, and gap closure assays were performed in six OSCC-derived cell lines upon treatment with varying concentrations of SC. PDE5 expression was determined in primary OSCC tissues by western blotting and immunohistochemistry. Results: Elevated PDE5 expression was observed in all cell lines. A concentration-dependent decrease in cell viability, invasion rate, and migration was observed after SC treatment. A significant correlation (p=0.05) was observed between elevated PDE5 expression and lymphatic infiltration in OSCC tissues. Conclusion: PDE5 plays an important role in carcinogenesis of OSCC, and the specific inhibition of PDE5 may be an effective chemotherapeutic strategy.