Objective To investigate the expression of nicotinamide phosphoribosyl transferase(NAMPT) in colon cancer tissues and analyze its physicochemical properties, secondary and tertiary structures, protein-protein interaction, subcellular localization and function by bioinformation.

Methods TCGA database and real-time polymerase chain reaction (qPCR) were used to verify the expression of NAMPT in colon cancer tissues. CCK8 test was used to verify the proliferation ability of SW480 cells transfected with NAMPT siRNA and control siRNA. Then, we applied bioinformatics software, such as ProtParam, Jpred4.0, Genecards, String, etc., to predict the physicochemical properties and functions of NAMPT.

Results The expression of NAMPT mRNA was significantly higher in colon cancer tissues than that in the adjacent tissues. The proliferation ability of SW480 cells transfected with NAMPT siRNA was much lower than control group. Bioinformatics analysis indicated that NAMPT was unstable acidic hydrophilic protein and consisted of 491 amino acids. Fourteen α helixes and seventeen β folds were predicted in the secondary structure. The global model quality estimation (GMQE) score of the tertiary structure was 0.97 and the Results showed that NAMPT had no functional domain, with only one conservative domain. NAMPT was abundant in the extracellular, nucleus and cytoplasm. This protein was involved in NAD+ biosynthesis, circadian rhythm, stress, metabolism reaction and aging.

Conclusion The overexpression of NAMPT in colon cancer tissues could be involved in various biological processes, and could regulate the biological behavior of tumor by different pathways.