Expression of Nampt in colorectal cancer and its clinical significance

Abstract

Objective To observe the expression of nicotinamide phosphoribosyltransferase (Nampt) in colorectal cancer tissues and paracancerous tissues, and to evaluate the associations between Nampt expression and clinicopathological parameters, as well as its correlation with the prognosis in patients with colorectal cancer. Methods Oncomine database was applied to investigate the expression characteristics of Nampt mRNA in colorectal cancer tissues and adjacent tissues. The immunohistochemical assay was used to detect the expression of Nampt protein in 93 cases of colorectal cancer tissues and their corresponding adjacent tissues. The clinical significance of Nampt was also analyzed by combining with its clinicopathological data. Results The expression level of Nampt mRNA and protein in colorectal cancer tissues was significantly higher than that in the corresponding paracancerous tissues (P=0.000). The high expression of Nampt protein was associated with higher levels of N stage (χ2=3.908, P=0.048), M stage (χ2=5.316, P=0.021), and TNM stage (χ2=11.930, P=0.001). Survival analysis showed that the overall survival of colorectal cancer patients with high expression of Nampt protein was significantly lower than those with low expression (26.02 vs. 45.37 months, P=0.017), but there was no correlation between Nampt protein expression and disease-free survival (13.72 vs. 14.29 months, P=0.5645). Cox regression analysis showed that high expression of Nampt protein was an independent risk factor for poor prognosis in patients with colorectal cancer [P=0.045, hazard ratio (HR)=1.963, 95% confidence interval (CI): 1.080-3.652). Conclusion The expression of Nampt in colorectal cancer tissues is higher than that in corresponding paracancerous tissues. The high expression of Nampt protein is related to the tumor stage. The high expression of Nampt in colorectal cancer patients may predict a poor prognosis. Key words: Nicotinamide phosphoribosyltransferase; Colorectal cancer; Immunohistochemistry; Prognosis