[2-methoxyestradiol induced apoptosis and expression of p53 gene in human acute T lymphoblastic leukemia cells].

OBJECTIVE: To explore the effect of 2-methoxyestradiol (2-ME2) on apoptosis of human acute T lymphoblastic leukemia cells, and its underlying mechanism. METHODS: The growth inhibition of CEM cells was detected by MTT assay; apoptotic cells were detected by DNA laddering analysis; the expressions of P53 mRNA and protein were detected by RT-PCR and Western blot respectively. RESULTS: 2-ME2 remarkably inhibited the CEM cell growth and the 50% growth inhibitory concentration (IC50) at 48 h was 2 µmol/L. The DNA ladder could be detected in CEM cells after treating with 2 µmol/L 2-ME2 for 24, 48 and 72 hours; after treating with 2 µmol/L 2-ME2 for 24, 48 and 72 hours, a time-dependent reduction of P53 mRNA and protein expressions was found in CEM cells. CONCLUSION: The anti-leukemia effect of 2-ME2 is completed through the induction of cell apoptosis. Down-regulation of P53 gene expression may be an underlying mechanism.