Effects Of Galectin-9 On Proliferation And Migration Of Glioma Cells And Its Mechanism

Background:Galectin-9 is a T-cell-derived eosinophilic granulocyte chemoattractant, firstly found in activated T cell, and then its existence was found in many normal tissues in human, with a variety of biological functions such as cell aggregation, conglutination, proliferation, apoptosis and inflammation regulation. Galectin-9 was found in Hodgkin’s lymphoma tissue. Now it has been verified that galectin-9 exists in many tumors, such as breast cancers, colon cancers and gastric cancers, and galectin-9 can influence tumor cells’biological behaviors. Existence of galectin-9 in glioma cells have not been reported, thus we investigate its potential effects on gliomas.Objective: To investigate the effects of exogenous galectin-9 on proliferation and migration of glioma cell lines and its potential mechanism, and to study the influence of lactose on galectin-9’effects.Methods:The expression of galectin-9 in glioma cell lines was detected by real time quantitative polymerase chain reaction. U251 was elected for further experiment. Exogenous galectin-9 was applied on the glioma cell line U251 at different concentrations (1、4、8、16ug/ml), the changes of proliferation and migration were tested by cell count kit-8 (CCK-8) and transwell chambers respectively at different 24、36h)after treatment. When the competitive inhibitor lactose was used after galecitn-9 applied, repeating the testing and detecting the difference in proliferation and migration with or without lactose.Results: The results of PCR showed that the expression of galectin-9 in four glioma cell lines was low or barely detected. In proliferation assay, after high concentrations of galectin-9 was added, the cell proliferation rates decreased apparently compared with control group (P<0.001). With time passing by, the cell proliferation rates decreased gradually(P<0.01). After treated with lactose, cell proliferation rate increased compared with untreated group when both groups has been galectin-9 treated before (P<0.05). In migration assay, after galectin-9 applied, the numbers of cells penetrating the micropomus membrane were decreasing compared with the numbers of cells of control groups (P<0.01). After treated with lactose, cell number increased compared with untreated group(P<0.05).Conclusion:Galectin-9 inhibited proliferation of glioma cells effectively in a time-and dose-dependent way, also inhibited migration of glioma cells. Its effects are dependent of carbohydrate recognition region and can be inhibited by inhibitor lactose. In conclusion, it provides a new way to the treatment of gliomas.