The Effects Of Down-Regulating MSI2 Gene On BCR-ABL Fusion Gene Expression In K562 Cell Line

Purpose: To explore the effects of MSI2 expression on BCR-ABL fusion gene expression in k562 cell line and to find out the influence upon proliferations of the cell whose MSI2 gene are down-regulated,we hope that we can find out new targets for CML therapy .Methods: After transfecting SiRNA of MSI2 to k562 cells, the expressions of MSI2 were detected by Real-time Quantitative PCR and western blot.Then we detected the expression of BCR-ABL in the tansfected cells and the proliferations of the cells added CFSE by FCM.Results: Significantly decreasing expressions of MSI2 gene in k562 cells ,which were tansfected SiRNA of MSI2 ,can be detected by Real-time Quantitative PCR,and the relatively quantitative(RQ) values of blank control group, negative control group and experimental group are (1±0), (0.954±0.072), (0.302±0.041) respectively.The difference between blank control group and experimental group is significant(P<0.05),as well as the one between negative and experimental group. Detecting by western blot,we also find that MSI2 are inhibited significantly ,and the gray-value ratios of MSI2/β-actin are respectively (0.832±0.029),(0.766±0.031),(0.537±0.083).Blank control group and experimental group are different significantly(P<0.001), and the difference between negative group and experimental group is significant,too(P<0.05).The expression of BCR/ABL fusion gene were detected using RT-PCR,which shows that the gray-value ratios of BCR-ABL/GAPDH are (0.834±0.047),(0.848±0.030),(0.639±0.041).A significant decrease were observed in experimental group,much less than blank group(P<0.001)and negative group(P<0.001) . FCM was used for detecting cell proliferation.At 24 h point,the PIs of blank ,negative and experimental groups are (2.88±0.122),(2.73±0.126),(2.01±0.179),respectively, (3.40±0.121)(3.21±0.086)(2.54±0.234)at 48 h,and(10.78±0.706)(9.98±0.242)(4.30±0.744)at72h. And the proliferations index(PI) of experimental group are declined ,which is contrast with the ones of blank control group( P<0.01, p<0.005, p<0.001 ) and negative control group(P<0.005, P<0.01, P<0.001). Conclusion: Down-regulating MSI2 gene can decrease the expressions of BCR-ABL fusion gene,which may account for its mechanism in inhibiting the proliferation of K562 cells.