Hu-antigen receptor (HuR) and cyclooxygenase-2 (COX-2) expression in human non-small-cell lung carcinoma: associations with clinicopathological parameters, tumor proliferative capacity and patients' survival

Hu-antigen R (HuR) is considered to play a central role in tumor formation, growth, and metastasis by binding to messenger RNAs (mRNAs) encoding proteins such as cyclooxygenase-2 (COX-2) and inducing their expression via mRNA stabilization and/or altered translation. The present study aimed to evaluate the clinical significance of HuR and COX-2 protein expression in non-small-cell lung carcinoma (NSCLC). HuR and COX-2 expression was assessed immunohistochemically on tissue microarrays of 81 surgically resected NSCLC and was analyzed in relation with clinicopathological characteristics and patients' survival. Enhanced total HuR expression was significantly associated with tumor histological type and presence of lymph node metastases, as well as with increased tumor proliferative capacity and poor patients' outcome (p=0.039, p=0.017, p=0.033, and p=0.022, respectively). Enhanced COX-2 expression was significantly associated with the presence of lymphovascular invasion and increased tumor proliferative capacity (p=0.031 and p=0.023, respectively). Concomitant elevated HuR/COX-2 expression levels were significantly associated with tumor histological type and increased proliferative capacity (p=0.002 and p=0.045, respectively). Enhanced total HuR expression, as well as its cytoplasmic localization, was significantly associated with increased COX-2 expression (p=0.015 and p=0.001, respectively). The present study supported evidence that HuR may participate in malignant transformation of NSCLC, reinforcing its usefulness as potential therapeutic target in this type of neoplasia.