[Sodium arsenite selectively inducing apoptosis of G2 + M phase NB4 cells].

OBJECTIVE: To explore the mechanism of sodium arsenite inducing apoptosis of NB4 cells. METHODS: The apoptosis of NB4 cells was studied by flow cytometry, DNA gel electrophoresis and Western blot analysis. RESULTS: 1. Sodium arsenite induced apoptosis of NB4 cells while the cells were arrested in G2 + M phase; 2. dUTP-FITC specifically labeled NB4 cells in G2 + M phase after the cells were treated with sodium arsenite; 3. After the treatment the expressions of cyclin A, E, D1, D2 and D3 of the NB4 cells did not change significantly, while the expression of cyclin B1 was up-regulated with prolongation of the treatment; 4. Some of S phase NB4 cells expressed high level cyclin B1 during the early period of treatment (16 h), but most of NB4 cells expressing high level of cyclin B1 were in G2 + M phase. CONCLUSION: Sodium arsenite selectively induced apoptosis of G2 + M phase NB4 cells, accompanied by upregulation of cyclin B1.