Objective：To investigate the expression of F-box and WD40 domain-containing7（Fbxw7） in acute T lymphocyte leukemia and its effect on cell growth as well as its mechanism. Methods：The mRNA expression of Fbxw7 in 62 patients with acute T lympho－cyte leukemia was detected by RT-PCR. The lentivirus vector carrying Fbxw7 overexpression was transferred to leukemia Jurkat cells and the effect of transfection was tested by RT-PCR and Western blot. And the proliferation of Jurkat cells was measured by MTT as－say. The cell cycle and apoptosis were examined by flow cytometry，and the expression of c-Myc and Cyclin E protein was checked by Western blot. Results：Expression levels of Fbxw7 mRNA in relapse group and initial group were significantly lower than those in normal healthy group（P<0.05）. After transfection，relative expression levels of Fbxw7 mRNA and protein in the Fbxw7 overexpression group（transfected with Fbxw7 overexpressed lentivirus vector） were significantly higher than those in the control group （no transfected cells） and negative control group（transfected with control lentivirus vector）（P<0.05）. Cell proliferation was not significantly influenced（P>0.05） after transfection of 24 h，while was significantly inhibited after transfection of 48 h and 72 h（P<0.05）. After transfection of 48 h，when compared with control and negative control groups，cell apoptosis and the proportion of cells in G0/G1 phase of Jurka cells were significantly increased in Fbxw 7 group，S phase and G2/M phase were significantly decreased，and relative expression levels of c-Myc and Cyclin E were significantly decreased，all with statistically significant difference（P<0.05）. Conclusion：Fbxw7 is low expression in acute T lymphoblastic leukemia，its overexpression can inhibit the proliferation of Jurkat leukemia cells and promote cell apoptosis，and its mechanism may be related to the down-regulation of c-Myc and Cyclin E protein expression.
