Association between expression of embryonic lethal abnormal vision-like protein HuR and cyclooxygenase-2 in oral squamous cell carcinoma

Background Increased cytoplasmic HuR expression has been noted in several cancer types, where it may contribute to the increased cyclooxygenase-2 (COX-2) expression observed during tumorigenesis and metastasis. Methods To assess the correlation between COX-2 and HuR in oral squamous cell carcinoma (OSCC), the expression patterns of HuR and COX-2 were assessed via immunohistochemistry analyses of 103 OSCC samples. Results Cytoplasmic HuR expression was significantly associated with COX-2 expression (p <.025) and lymph node metastasis (p <.050) and distant metastasis (p <.025). In multivariate analysis, cytoplasmic HuR expression was identified as an independent prognostic parameter for reduced overall survival. The inhibition of HuR expression by siRNA or leptomycin B (LMB) caused a reduction in the inducibility of COX-2 in oral cancer cells. Conclusion Our results indicate that the cytoplasmic expression of HuR is associated with COX-2 expression in OSCCs and HuR can regulate COX-2 expression in oral cancer cell lines.