The expression of Galectin-9 in colorectal cancer and its significance

Objective: To study the expression of Galectin-9 mRNA and protein in colorectal cancer (CRC) and its clinical significance. Methods: Galectin-9 mRNA and protein levels were detected in 45 cases of CRC and 20 cases of normal colorectal epithelial tissues by real-time PCR analysis and immunohistochemisty staining. The relationship between the expression levels of Galectin-9 and clinicopathological features was analyzed. Results: The levels of Galectin-9 mRNA were lower in CRC than that in normal colorectal epithelial tissues (19.80 ± 17.37 vs 45.34 ± 43.81, P<0.05). The positive expression ratios of Galectin-9 protein in CRC and normal colorectal epithelial tissue were 62% (28/45) and 90% (18/20), respectively; the difference was of statistical significance (P< 0.05). The low expression of Galectin-9 correlated with the distant metastasis of CRC (P<0.05). But it had no correlation with the age and sex of patients, depth of tumor invasion, lymph node metastasis, differentiation degree, tumor stage, and tumor location. Conclusion: The expression of Galectin-9 mRNA and protein in CRC is weak. Weak expression of Galectin-9 is associated with distant metastasis of CRC. Galectin-9 may become a prognostic factor or a gene therapy target for CRC.