Figure 3.

GA3 induces apoptosis in HL-60 cells. (A) Electrophoresis of DNA fragmentation. HL-60 cells were exposed to GA3 at indicated concentrations for 4 h (left) or treated with 4 μmol/L GA3 for indicated times (right), fragmented DNA was extracted and separated in 1% agarose gel electrophoresis. (B) DAPI staining assay. DAPI-stained nuclei of HL-60 cells untreated or treated with 2 μmol/L or 4 μmol/L GA3 were observed using a microcopy (×200). (C) PI staining for flow cytometry. Cells were treated with GA3 for 4 h at indicated concentrations (upper panel) or treated with 4 μmol/L GA3 for indicated times (lower panel). Cells were analyzed using FACS after they were fixed by 70% ethanol and stained with PI. Sub G₀/G₁ DNA content of HL-60 cells were collected as apoptotic cells. The results are typical of those obtained in three independent experiments yielding similar results.