The Study On The Correlation Between The Expression Of Galectin-3 And The Angiogenesis, Infiltration As Well As Metastasia In Esophageal Squamous Cell Carcinoma

Background and Objective:Galectin-3,previously described as IgE binding-protein,CBP35,CBP30,Mac-2,L-29, L-31 and L-34,is one of theβ-galactoside-binding proteins,which bind to the carbohydrate portion of cell surface glycoproteins or glycolipids.Studies have revealed that galectin-3 is consists of three domains:a NH₂-terminal domain;a repetitive collagen-like sequence rich in glycine,proline,and tyrosine;and a COOH-terminal carbohydrate recognition domain (CRD,lectin domain).Galectin-3 is expressed widely in epithelial and immune cells.It plays an important role in regulation of cellular proliferation,differentiation and apoptosis, and it may participate the carcinogenesis,development and the formation of vessels of tumor.Now Galectin-3 has become a focus in medical research.Esophageal carcinoma is a kind of common diseases in China.It was the fourth in the death rate of malignant tumor in china.Most cases causing the death of esophageal carcinoma are tumor's invasion and metastasis.So exploration about invasion and metastasis of esophageal carcinoma has become a focus.At present,the reports about Galectin-3 expression in esophageal squamous cell carcinoma were absence and the correlation between its expression and clinical pathology was not clear.There were no reports about the relationship between Galectin-3 expression and angiogenesis of esophageal carcinoma.In this study,we used RT-PCR to detect Galectin-3 mRNA and investigated the protein expression of Galectin-3,MMP-2,Bcl-2 by means of immuno-stainning in cancerous and adjacent normal tissue samples of esophageal carcinomar.Furthermore,we analyzed the possible associations of these parameters with main clinicopathologic data of esophageal carcinoma.The vascular endothelial cells were labeled by CD₃₄ to investigate whether there were dependability between Galectin-3 and and esophageal carcinoma angiogenesis base on the microvascular density(MVD). Material and Methods:1.The expression of Galectin-3,MMP-2 and Bcl-2 protein in 80 cases of esophageal carcinoma and 22 cases normal esophageal tissues were detected by the immunohistochemical stain(IHC).Immunohistochemistry was also used to examine the expression of CD₃₄.We calculated the number of microvessel by anti-CD₃₄ monoclonal antibody to achieve MVD in carcinoma tissue and correspondingly adjacent normal esophageal tissue.2.Galectin-3 mRNA expression in 36 cases of esophageal carcinoma and their corresponding normal tissues were studied by RT-PCR(Reverse Transcription Polymerase Chain Reaction) usingβ-actin as internal standard.3.Statistical analysis:The data were processed by the SPSS software v11.0.Chisquared test was used in data of quantity.T-rest or ONE-WAY ANOVA method was used in data of quality.Spearman method was applied for the correlation analysis.Results:1.The positive incidence of Galectin-3 protein expression in esophageal carcinoma was 77.5%(62/80),while in normal esophageal tissues it was 27.3%(6/22).Significant difference was found between normal esophageal tissues and esophageal carcinoma (P＜0.05).The expression of Galectin-3 protein was correlated with the degree of differentiation,depth of infiltration,and lymph node metastasis,(P＜0.05),but seemed to not correlated with patients' age,sex,and tumor size.2.The positive incidence of MMP-2 protein expression in esophageal carcinoma was 82.5%(66/80),while in normal esophageal tissues it was 45.5%(10/22).Significant difference was observed between normal esophageal tissues and esophageal carcinoma (P＜0.05).The expression of MMP-2 protein was correlated with the degree of differentiation,depth of infiltration,and lymph node metastasis,(P＜0.05).Furthermore,a significant positive relationship was demonstrated between the expression of Galectin-3 and MMP-2 proteins(P=0.006,r=0.303).4.The positive incidence of Bcl-2 protein expression in esophageal carcinoma was 76.3%(61/80),while the protein was observed absent in the normal esophageal tissues.The expression of Bcl-2 protein was correlated with the degree of differentiation and lymph node metastasis,(P＜0.05).A significant positive relationship was also found between the expression of Galectin-3 and Bcl-2 proteins(P=0.003,r=0.332). 5.The positive incidence of Galectin-3 mRNA expression in esophageal carcinoma was 77.8%(28/36),while in normal esophageal issues it was 13.9%(5/36).Significant difference was found between normal esophageal tissues and esophageal carcinoma (P＜0.05).The expression of Galectin-3 protein was correlated with the degree of differentiation,depth of infiltration,and lymph node metastasis,(P＜0.05),but seemed to not correlated with patients' age,sex,and tumor size.Conclusions:We demonstrated that the abnormal expression of Galectin-3 may promote the occurrence and development of esophagus carcinoma at the gene and the protein level. Galectin-3 may play important roles in anti-apoptosis and promoting the invasion and metastasis in esophagus carcinoma through the synergistic effect with MMP-2 and Bcl-2 protein,as well as the participation in esophageal carcinoma angiogenesis.Therefore, Galectin-3 has the possibility to become the new target spot for esophagus cancer's clinical diagnosis and treatment.