Expression Of Src Gene In Glioma And Its Effect On The Malignant Biological Behavior Of Glioma Cell Line

Along with the progress of medical technology,the discovery rate of central glioma is increasing year by year,which made central glioma no longer a rare disease in recent years.Comparatively speaking,the treatment of gliomas is still in the bottleneck,and the reported data of curative effect has no obvious improvement in these recent 30 years.Thus,it's imminent to search for a new glioma therapy.Src gene is found the earliest by human as proto-oncogene,the protein product Src is the most widely distributed protein kinases in the body,through various signaling molecule of phosphorylation cells,they are involved in regulating cell proliferation,differentiation,and a series of physiological activities.It is known that in colon cancer,breast cancer and prostate cancer,the expression level of Src is positively related with the malignant degree of tumor.However,the research of Src's role played in the development of glioma is almost blank.In this study,the author tries to explore the expression and regulation mechanism of Src in glioma,and clearly express Src's biological role in the tumor characteristics of glioma.First of all,we found that the expression of protein Src in clinical surgical specimens of glioma patients is significantly higher than normal brain tissue(P < 0.05),among which,low grade(WHO I &II)and high grade glioma(WHO III and IV)are respectively 80% higher and 190% higher than that of normal brain tissue,and high level of Src is significantly higher than low grade gliomas(P<0.05).Meanwhile,the expression of inactivation of the protein Src,phenotypic Try530-P-Src has no obvious difference with normal brain tissue(P>0.05),but ratio of Try530-P-Src/Src dropped significantly compared with in normal brain tissue(P < 0.05).Also,we observed that the expression level of specificity regulatory proteins CSK,which is on the "switch" site of protein Src Try530,are only 46% of that in the normal brain tissue and 39% respectively when it's in low grade and high grade(P < 0.01).The above data suggests glioma,the expression level and relative activity of Src are significantly increased in gliomas,which is positively proportional to the glioma pathology classification.The relative activity of pathological Src increased mainly due to the protein Src function dysregulation in glioma.Then,we do evaluation to the prognosis of patients on the basis of expression level of Src,Try530-P-Src and CSK protein among gliomas surgical specimens.We found the median time for overall survival and progression-free survival of Src low expression group are 18 months and 16 months respectively,while the date of high expression group are13 months and 9 months,which shows statistically significant differences between the two groups.(P<0.05)On the contrary,the median time for overall survival of Try530-P-Src of low expression and high expression are 10 months and 12 months respectively(P<0.05),and median time for progression-free survival are 11 months and 5 monthsrespectively(P<0.05).The above data showed that the prognosis of patients with gliomas is negatively proportional to the amount of the Src expression,while positively proportional to Try530-P-Src,which shows high Src expression,is poor indicators for prognosis.In order to further clarify the Src influence on glioma,we made three groups of different active Src cell lines in the glioma cell line,U-138 MG,which are CSK mi RNA treatment group,the Src specific inhibitors Saracatinib group,and blank control group.The result shows,response sensitivity of cells of Saracatinib group to temozolomide increased significantly,IC50 is changed by control group from 544.8u M(95%credibility interval138.2 – 2148 u M)to 14.05 u M(95%credibility interval2.55 – 77.45 u M).However,IC50 of CSK mi RNA treatment group is changed to 5,666 u M(P among 3 groups<0.05).Then,in Scratch experiment,on the 5th day,the expanding speed and range of Saracatinib group and CSK mi RNA treatment group are respectively significantly reduced and increased compared with blank control group(P among 3 groups <0.05),and the trend still maintains on the 14 th day.Then,we compare the ability to migrate of cell line.The ability to migrate of Saracatinib group and CSK mi RNA treatment group are separately298 + 64 cell/mm2 and 281 + 71 cell/mm2,which is significantly lower and higher than the blank control group(P<0.05).Finally,we compared expression among three groups of growth associated protein,EGFRvlll and pro-apoptotic protein,p53.We found,in Saracatinib treatment group,the relative expression of U-138 MG cells EGFRvlll and p53 were 76% + 9.5%and138% + 14%of the control group respectively(P<0.05).Comparatively speaking,in CSK mi RNA treatment group,the relative expression of EGFRvlll and p53 were 150% + 7.1 and 65% + 16% of the control group respectively(P<0.05).The above data suggests the Src can significantly increase the vicious behavior of glioma cells.In order to verify the tangibility of Src for EGFRvlll and gene p53,we adopt the chromatin immune coprecipitation technique to test inhibitory proteins H3K27Me2 of startup of EGFRvlll and gene p53.We found that when U-138 mg cells after dealing with the Saracatinib,aggregation degree of H3K27Me2 in EGFRvlll promoter increased significantly,which is 1.2 times that of the normal(P <0.01)while there is a significant decline in gene p53 promoter(0.24 + 0.2,P < 0.01).on the contrary,when U-138 mg cells after dealing with CSK micrornas,aggregation degree of H3K27Me2 in EGFRvlll promoter significantly reduced(0.77 + 0.11,P < 0.05),while there is a significant rise in gene p53 promoter(3.9 + 0.7,P < 0.05).In conclusion,as classic proto-oncogenes,Src was reported for the first time there exits abnormal levels among expression level,functional level and regulate level in glioma in this paper.This study found that in glioma clinical specimens,the expression of Src was obviously higher than that of normal brain tissue,and increased significantly with the increased level of tumor,and expression is negatively correlated with patient survival.In U138 MG cell line,interference of the expression of Src can inhibiting invasion and migration of tumor cell,also can promote tumor's susceptibility to temozolomide,which indicates that the Src may become the new targets for glioma treatment.Suchcharacteristic makes Src probably to become a new targeted therapeutic method in glioma.