Osteopontin, CD44, and NFκB expression in colorectal adenocarcinoma

Abstract

ABSTRACT Background and Aim: Osteopontin (OPN) binds to CD44 and nuclear factor‐κB (NFκB) and mediates tumorigenesis, invasion, and metastasis, but the relationships involved are not fully understood. We thus examined the expressions of OPN, CD44, and NFκB in colorectal adenocarcinomas. Methods: Two hundred and ninety two patients with colorectal adenocarcinoma were immunostained with OPN, CD44, CD44v6, CD44v3, and NFκB monoclonal antibodies in microarray blocks. Real‐time RT‐PCR with OPN was performed with fresh frozen tissue in 25 cases. Results: OPN, CD44, and NFκB protein expression was noted in 62.4%, 27.7% and 84.4% of the adenocarcinoma tissues compared to 55.4%, 4.2% and 35.3% of the paired normal colonic mucosa. NFκB protein expression was correlated with OPN (p < 005) and CD44 (p < 0.005) but CD44 expression was not correlated with OPN. CD44 protein expression was correlated with location of the tumor, lymphatic invasion, lymph node status and stage, and NFκR expression was correlated with tumor location. OPN protein expression was not correlated with any clinicopathologic factor examined. OPN mRNA expression was higher in tumor tissue than in paired normal mucosa, which was not statistically significant. Lymph node status and perineural invasion were prognostic factors based on Cox analysis but OPN, CD44, and NFκB expression were not associated with patients' survival. Conclusions: CD44 may be partly involved in the progression of colorectal adenocarcinoma. The role of OPN and NFκB may be minor in the carcinogenesis and tumor progression.