Gene-expression profiling in Chinese patients with colon cancer by coupling experimental and bioinformatic genomewide gene-expression analyses - Identification and validation of IFITM3 as a biomarker of early colon carcinogenesis

BACKGROUND. Expression microarrays are widely used for investigating the nature and extent of global gene-expression changes in human cancer. Accurate genomewide gene-expression profiles have not been conducted in colon tumor and normal colon tissue specimens obtained from Chinese patients. METHODS. in the present study a pure population of colon cancer and normal colon cells was obtained and the global gene-expression differences were compared in the 2 cell types using combined experimental and bioinformatic approaches. Various categories of genes that were differentially expressed in those 2 types of cells were identified, including a novel candidate tumor marker, IFITM3. RESULTS. Elevated IFITM3 expression in colon cancer cells was first confirmed using quantitative real-time polymerase chain reaction. IFITM3 protein expression in human colon cancer specimens was further analyzed using both tissue microarray and standard tissue sections by immunostaining analyses. It was found that there was a significant IFITM3 increase in adenoma as compared with that in normal colon tissue. CONCLUSIONS. The data suggest that IFITM3 plays an important role in early colon cancer development.