[Effect of CPEB4 on Migration and Cycle of Chronic Myeloid Leukemia Cell]

To investigate the effects of CPEB4 on the migration and cycle of K562 cells and the changes of protein molecules that may be involved in the regulatory mechanism.

Western blot was used to detect the expression of CPEB4 in normal leukocytes and K562 cells. The overexpression plasmid pcDNA3.1(+)-His-CPEB4, silencing plasmid pPLK+Puro-CPEB4 shRNA were transfected into K562 cells by electroporation so as to change CPEB4. The transfection efficiency was detected by Western blot. Finally, the migration and cycle of different cells were detected by Transwell chamber and flow cytometry.Western blot was used to detect the expression changes of MMP2, MMP9, CDK4, CyclinD1 and P21 proteins.

Compared with normal white blood cells, the expression of CPEB4 protein in K562 cells was significantly enhanced (P＜0.01); Compared with the control group, CPEB4-silenced K562 cells showed that the cell migration ability was significantly enhanced (P＜0.01); G₀/G₁ phase cell ratio reduced, G₂/M phase cell ratio increased, and cell cycle progression accelerated（P＜0.01）, The expression levels of MMP2 (P＜0.05), MMP9 (P＜0.05), CDK4 (P＜0.01), CyclinD1 (P＜0.01) proteins increased significantly. The expression level of P21 protein significantly decreased (P＜0.01). The migration ability of K562 cells after CPEB4 overexpression was decreased (P＜0.01), the cell ratio of G₀/G₁ phase in the cell cycle increased, the cell proportion of S phase decreased and the cell cycle progression was arrested at G₀/G₁ phase (P＜0.01). The expression of P21 protein increased, MMP2 , MMP9, CDK4, CyclinD1 protein expression decreased significantly（P＜0.05-0.01）.

CPEB4 can inhibit the migration of K562 cells and arrest cell cycle progression at G₀/G₁ phase. Its mechanism may be related with regulating the exprossion of MMP2, MMP9, CDK4, CyclinD1 and P21 proteins.