Gene Silencing Of Galectin-3 Changes The Biological Behavior Of Eca109 Human Esophageal Cancer Cells

Objective:Galectin-3 (Gal-3) is a β-galactoside-binding lectin that is capable of specifically binding to the carbohydrate domain of glycoproteins or glycolipids on cytomembrane. Gal-3 is widely expressed in epithelial cell and immunocyte, and participates in the regulation of multiple biological functions including cell growth, adhesion, proliferation, differentiation, tumorigenesis as well as angiogenesis. Studies have demonstrated that Gal-3 is overexpressed in substantial malignant tumors such as glioma, lung cancer and breast cancer. However, there is little study to explore the expression and roles of Gal-3 in esophageal cancer. On the basis of our previous study that has identified the expression of Gal-3 in esophageal cancer, this study aims to investigate the effects of galectin-3 silencing on proliferation, apoptosis, migration and invasion in esophageal cancer.Methods:1. Small interfering (si) RNA was utilized to transfect esophageal cancer Eca109 cell, and we evaluated the transfection efficiency by fluorescence microscopy.2. The expression levels of Gal-3 after siRNA transfection were measured by western blot and reverse transcription polymerase chain reaction (RT-PCR) analyses, while the siRNA that significantly inhibits Gal-3 expression was selected to conduct subsequent function studies.3. Cell Counting Kit-8 (CCK-8) assay was used to analyze the cell proliferation ability at 24h,48h,72h and 96h after transfection.4. Annexin V/7-amino-actinomycin double-staining by flow cytometric analysis was utilized to mark the apoptotic cells, investigating the effect of Gal-3 on cell apoptosis.5. By counting the cell number through artificial matrix membrane in Transwell chamber, we examined the cell migration and invasion abilities, and assessed the effect of Gal-3 on cell migration and invasion.Results1. We observed that weak fluorescence was widely distributed at the microscope field after siRNA transfection, which was consistent with the distribution of Eca109 cells, and the transfection efficiency was obove 85%. The result indicated that siRNA has been transferred into the Eca109 cells, and the experiment acquired better transfection efficiency.2. Gal-3 expression at protein and mRNA levels were significantly inhibited after siRNA transfection compared with negative control and untreated control (P<0.05).3. At 72h and 96h after transfection, cell proliferation was clearly decreased in siGal3 group (P<0.05), but no statistical difference was observe between siGal-3 group and control group (P>0.05).4. In comparison with control groups, the down-regulation of Gal-3 significantly increased the apoptosis rate of Eca109 cell (P﹤0.05), indicating that Gal-3 may play inhibitory role in cell apoptosis.5. The cell migration and invasion in siGal3 group were lower than control groups (P<0.05), which demonstrated that Gal-3 expression was associated with cell migration and invasion, and knockdown of Gal-3 could attenuate the migration and invasion abilities of Eca109 cell.Conclusion:Gal-3 plays an important role in malignant tumor progression. Silencing of Gal-3 expression in Eca109 cells could decrease the cell proliferation, migration and invasion, while enhancing the apoptosis ability. Therefore, the exploration of Gal-3 in esophageal cancer development might offer new target for esophageal cancer treatment.