Expression of GAEC1 mRNA and protein and its association with clinical and pathological parameters of patients with colorectal adenocarcinoma.

Aim: GAEC1 (Gene amplified in esophageal cancer 1) is an oncogene with key regulatory roles in the pathogenesis of oesophageal and colorectal carcinomas. The aim of this study was to investigate expression profiles and clinicopathological significance of GAEC1 mRNA and protein in patients with colorectal carcinomas.

Method: Matched cancer and non-cancer fresh frozen tissues were prospectively collected from 80 patients diagnosed with colorectal adenocarcinoma (39 men and 41 women). The tissues were sectioned for RNA extraction and cDNA conversion and quantified by a real-time polymerase chain reaction. GAEC1 protein expression was analysed by immunohistochemistry using a custom made GAEC1 antibody.

Result: GAEC1 mRNA was upregulated in majority (52%, n=42/80) of the colorectal carcinomas when compared to the matched non-neoplastic tissues. High expression of GAEC1 mRNA as correlated with patients of younger age (p=0.008), with lower grade carcinoma (p=0.028), presence of synchronous adenocarcinomas (p=0.034) and without any associated adenomas (p=0.047). In addition, patients with high GAEC1 mRNA overexpression had a shorter survival time. Furthermore, high GAEC1 protein expression was noted among patients having perforated colorectal carcinoma (p=0.04).

Conclusion: The high expression of GAEC1 mRNA/protein as well as its correlation with multiple clinicopathological characteristics in patients with colorectal carcinoma strongly suggests that GAEC1 is a key regulator in the initiation of colorectal carcinogenesis.