OBJECTIVETo investigate the correlation between galectin-1 expression and the biological behaviors of human colorectal carcinoma.

METHODSSP immunohistochemistry was used to detect the expression of galectin-1 in 158 paraffin-embedded specimens including 30 normal mucosa, 25 adenoma, 65 colorectal carcinoma and 38 metastatic tumor specimens. Real-time RT-PCR was used to detect galectin-1 mRNA expression in 32 fresh specimens of colorectal carcinoma and normal mucosa.

RESULTSThe positive expression level of galectin-1 was significantly different between normal mucosa, adenoma, colorectal carcinomas and metastatic tumors, with positivity rate of 0, 8%, 66% and 86%, respectively (P<0.05). Galectin-1 expression in moderately or well differentiated colorectal carcinomas was significantly lower than that in poorly differentiated ones (P=0.031), and its expression in invasive carcinomas was significantly higher than that in non-invasive carcinomas (P=0.000). Galectin-1 expression in colorectal carcinomas was significantly related with lymph node metastasis (P=0.004). In poorly differentiated colorectal carcinomas, the expression of galectin-1 mRNA was about 2.27 times that in moderately or well differentiated colorectal carcinomas (P=0.00); galectin-1 mRNA expression in invasive carcinoma was 1.98 times that in non-invasive carcinoma (P=0.002). In tumors with lymph node metastasis, galectin-1 mRNA expression was 1.42 times that in tumors without metastasis (P=0.018).

CONCLUSIONGalectin-1 can be involved in the development and progression of colorectal carcinoma, and may relate to the infiltration, differentiation and lymph node metastasis of colorectal carcinoma.