Involvement of galectin-3 expression in colorectal cancer progression and metastasis

Galectin-3 is a beta-galactoside-specific lectin that binds to laminin suga r-sites and is involved in tumor malignancy. Galectin-3 expression in relat ion to primary tumor and liver metastasis of colorectal cancer was examined to determined its involvement in cancer progression and metastasis. Immuno histochemical staining of galectin-3 was performed on 117 primary lesions a nd 15 liver metastases of colorectal cancer using TIB166 monoclonal antibod y. The expression of galectin-3 was evaluated by grading the intensity of t he staining as either negative, weakly positive, or strongly positive. Norm al mucosa of all patients were strongly positive for galectin-3, but the st aining in these tissues was still significantly less than in the primary le sions of the cancer (31.6%). Galectin-3 expression in the primary lesions w as significantly increased, correlating with the progression of clinical st age (p=0.0224), liver metastasis (p<0.0001), venous invasion (p=0.0048), an d lymph node metastasis (p=0.0289). Liver metastatic lesions also showed up -regulated levels of galectin-3 compared to the primary lesions (p=0.0030). The group showing strongly positive galectin-3 had a significantly poorer prognosis than the negative/weakly positive group in terms of disease-free survival (p=0.0224). The strong expression of galectin-3 in colorectal canc er correlates with cancer progression, liver metastasis, and poor prognosis for patients.