The Expression And Significance Of Galectin-3 And Smad4 In Human Colorectal Carcinoma

Background: Colorectal carcinoma is one of the most common malignancies.The incidence and deathrate of colorectal carcinoma is increasing in recent years. Metastasis is the major cause of death in patients with colorectal carcinoma , It is urgent to find out the metastasis associated factors so as to work out new preventive and therapeutic methods.Galectin-3 is a galactose-link-protein.It links with the sugar-link-Regi- on of specialsugar-protein in cell surface.Studies have showed that Galectin-3 is generally expressed in endothelial cell and tumor and plays a role in regulating the growth,differentiation,echoand anoikis of cell.It is involved in the process of tumor translation.To detect the level of Galectin-3 is very important for understanding the metastasis of tumor and evaluating prognosis.TGF-β(1transforming growth factor-β₁)can play an important role in the process of cell apoptosis and tissue repair. Smad4,a suppressor gene,performs a central role in transmitting signals form TGF-beta.Smad4 was first identified as a tumor suppressor gene of pancreatic. A lot of studies have showed that the gene mutation of Smad4 stops the passing of single .Cell escape the control of TGF-β.Gene mutations and low expression of Smad4 are related to the occurrence and metastasis of malignancies.Objective: To evaluate the expressions of Galectin-3 and Smad4 in normal colonic epithelium,adenoma and colorectal carcinoma and to explore the role of Galectin-3 and Smad4 in pathogenesis and matastasis of colorectal carcinoma so that some fundamental date might besupplied to the study of metastasis-associated factors.Method: Immunohistochemistry(SP) method is used to detect the expression of Galectin-3 and Smad4 in 20 cases of normal mucosa,33 cases of adenoma,55 cases of carcinoma . Use Pearson Chi-square and Fisher's Exact Test to test the difference of every group.Result:1.There were positive expressions of Galectin-3 and Smad4 in normal mucosa cases,adenoma cases and carcinoma cases. The expression of the Galectin-3 in colorectal carcinoma was significantly higher than normal colonic epithelium and adenoma.Also,the expression of Galectin-3 in carcinoma was significantly higher than in normal colonic epithelium(X²=31.24 P=0.000);The expression of the Galectin-3 in colorectal carcinomas with poor differentiated was significantly higher than that of the well differentiated one( X²=6.199 P=0.012);The expression of the Galectin-3 in colorectal carcinomas with lymph node metastasis was significantly higher than that without lymph node metastasis one( X²=10.479 P=0.001)。2. The expression of the Smad4 in colorectal carcinoma was significantly lower than normal colonic epithelium and adenoma.Also,the expression of Smad4 in carcinoma was significantly lower than in normal colonic epithelium(X²=9.916 P=0.007);The expression of the Smad4 in colorectal carcinomas with well differentiated was significantly lower than that of the poor differentiated one ( X²=13.077 P=0.000 ) ; The expression of the Smad4 in colorectal carcinomas with lymph node metastasis was significantly lower than that without lymph node metastasis one( X²=7.707 P=0.006).3.The expressions of Galectin-3 and Smad4 were not correlated in colorectal carcinomas cases (P>0.05).Conclusion:1.The higher expressions of the Galectin-3 is closly correlated with the pathogenesis,differention and metastasis of colorectal carcinoma.2.The lower expressions of the Smand is closly correlated with the pathogenesis,differentiated and metastasis of colorectal carcinoma.3.The higher expressions of Galectin-3 and the deletion of Smad4expression might play an important role in the evaluation of prognosis. Galectin-3 and Smad4 might be useful tumor markers for estimating the differention and metastasis of colorectal carcinoma.Detections of Galectin-3 and Smad4 have importate singnificase in maybe estimating the colorectal carcinoma progression and potentiality of lympho node metastasis.