Abstract: Objective To find factors related to colorectal adenocarcinoma invasion and migration. Methods The data of colorectal adenocarcinoma in TCGA and GEO databases were collected for SAM differential analysis. The differentially expressed genes were collected through DAVID, and genes related to invasion and migration were identified. In addition, cancer and paired adjacent tissues from 50 cases of Chinese colorectal adenocarcinoma patients with detailed clinical and prognostic information were collected for immunohistochemical staining to verify the above results. The ROC curve was drawn to evaluate the ability of this gene or its encoded protein for colorectal adenocarcinoma diagnosis. Results Totally 6 clusters of migration-related genes were found by DAVID analysis (p<0.05). The down-regulated genes were DLC1, EPB41L3, KIT, PARVA, SLC9A3R1 and TPM1. NHERF1, encoded by SLC9A3R1, is a scaffold protein that interacts with cytoskeleton and various signaling proteins. Data showed that both mRNA and protein levels of NHERF 1 in colorectal adenocarcinoma were lower than those in normal tissue, and its expression was decreased in high-grade and lymph node metastasis. Conclusions The decreased expression of NHERF1 is an independent factor associated with poorer survival of colorectal adenocarcinoma patients, which may result from its metastasis. Decreased expression of NHERF1 is a potential indicator for prediction of colorectal adenocarcinoma prognosis.

Key words: TCGA, colorectal adenocarcinoma, invasion and migration, Na+/H+ exchanger regulatory factor 1(NHERF1)