FIGURE 2.
Cell cycle-dependent and -independent expression of Survivin in human leukemia cells. Fractions enriched with cells at each phase of the cell cycle were separated by counterflow centrifugal elutriation. A, representative DNA histogram of each fraction subjected to flow cytometry after staining DNA with PI. Upper left, no fractionation; upper right, G0/G1 phase-enriched fraction; lower left, S-phase-enriched fraction; lower right, G2/M-phase-enriched fraction. B, immunoblot analysis of fractions of t(17;19)+ ALL cells or t(17;19)− ALL cells enriched with cells in the G0/G1- (G), S- (S), or G2/M (M)-phase. Survivin (arrow 1), E2A-HLF (arrow 2), and α-tubulin (arrow 3) proteins were detected with specific antibodies. C, levels of Survivin and α-tubulin proteins were determined by the band intensity on autoradiograms from B. Levels of Survivin were normalized to levels of α-tubulin, and amounts shown are relative to amounts in UOC-B1 cells in the G0/G1-phase.