The expression profiles of the galectin gene family in colorectal adenocarcinomas

Abstract

We aim to investigate the expression profiles of galectin family genes (galectins-1, 2, 3, 4, 7, 8, 9, 10, and 11) in colorectal carcinomas. Messenger RNA (mRNA) expression of galectin family members (1, 2, 3, 4, 7, 8, 9, 10, and 12) was analyzed by real-time polymerase chain reaction in colorectal tissues from 201 patients (54 noncancer colorectal tissues, 49 adenomas, and 98 adenocarcinomas). Galectin-1 and galectin-3 protein expressions were determined by immunohistochemistry. In general, high galectin mRNA expression was noted in colorectal carcinomas in early stages of their pathogenesis. Significant differences in galectins-2, 3, 7, 8, and 10 mRNA expression were associated with pathologic stages (P<.05). Increased prevalence of galectins-2, 7, 8, and 10 mRNA overexpression was noted in nonmetastatic colorectal carcinomas (P<.05). Galectin-1 and galectin-3 proteins were present in the nucleus and cytoplasm of the colorectal tissues and expressed significantly higher in colorectal carcinomas when compared to colorectal adenomas (61% and 95%, respectively). Patients with colorectal carcinoma with high levels of galectin-3 mRNA and protein expression showed better prognosis (P=.052). To conclude, many novel correlations between the deregulation of galectin family genes and various clinicopathological features in colorectal adenocarcinoma were noted. Overexpression of galectins at the mRNA level and proteins were predominant in earlier stages of colorectal carcinomas. These altered expression patterns of galectin genes suggest the multifunctional role of galectin genes in the regulation of colorectal cancer development, progression, and metastasis.