Expression of thymidylate synthase and dihydropyrimidine dehydrogenase in oral squamous cell carcinoma: possible markers as predictors of clinical outcome

Abstract

Conclusions. Our results suggest that assessment of dihydropyrimidine dehydrogenase (DPD) in oral squamous cell carcinoma (OSCC) may be a useful tool in evaluating clinical outcomes. Objective. The purpose of this study was to estimate the possibility of using thymidylate synthase (TS) and DPD as predictive values of clinical outcomes in OSCC. Materials and methods. The expression of TS and DPD was examined by immunohistochemistry (IHC) and the real-time reverse transcription-polymerase chain reaction method in 23 patients with OSCC, and the association with clinicopathological factors was determined. Immunohistochemical expression of p53 and P-glycoprotein (P-gp) was also examined. Results. Neither TS protein nor TS mRNA expression showed any significant correlation to clinicopathological factors. In contrast, the patients with high DPD expression had significantly higher levels of recurrence compared with those with low DPD expression (p = 0.016). Similarly, six of seven patients with relapse had higher DPD mRNA expression values than the median value in the patients examined. On the other hand, no association was observed between TS or DPD and p53 or P-gp expressions.

• Oral squamous cell carcinoma
• thymidylate synthase
• dihydropyrimidine dehydrogenase
• p53
• P-glycoprotein