Tissue and serum galectin-1 expression in patients with colorectal carcinoma.

BACKGROUND/AIMS: To observe the expressing model of galectin-1 in colorectal carcinoma (CRC) progress.

METHODOLOGY: The expression of galectin-1 in peritumor, adenoma and CRC tissues using immunohistochemistry, western-blotting and RT-PCR was detected. Serum galectin-1 concentrations were detected by ELISA.

RESULTS: Galectin-1 intensities in peritumor, adenoma and CRC tissues increased serially. Galectin- 1 expressed in the extracellular matrix of peritumor and pathological colorectal tissues mainly, while almost none was detected in colorectal epithelia. Different colorectal tissues expressed galectin-1 with different intensities. Non-parametric tests showed increased galectin-1 intensities were in peritumor, adenoma and carcinoma tissues (p<0.001). The over-expressing rates of galectin-1 in CRCs from Dukes A to D stage were increased significantly (p<0.001). Differently expressing intensities of galectin-1 were in different invasive locations of CRCs. RT-PCR showed that no statistically significant differences of galectin-1 mRNA were observed among peritumor colorectal tissue, adenoma and CRC tissues (p>0.05). Serum concentrations of galectin-1 decreased from healthy individuals to Dukes D CRCs. The differences between any of the groups were significant (p<0.05).

CONCLUSIONS: Stronger intensities of galectin-1 protein in the extracellular matrix of CRC tissues than those of peritumor and adenoma tissues, with no significant differences in the mRNA levels of galectin-1. Interestingly, serum galectin- 1 concentrations in patients with CRC decreased significantly. Above all, we presume that overexpression of galectin-1 protein in the CRCs is derived possibly from secreted galectin-1 from other normal tissues that cumulate in the stroma.