Notch-mediated growth inhibition and apoptosis in a range of human B-cell malignancies. (A) Notch1-induced growth inhibition in human Hodgkin and myeloma cell lines. Growth inhibition in Hodgkin (L428) and myeloma (RPMI 8226, U266, NCI-H929) cell lines stably transduced with tamoxifen-inducible ER-ICN1 retrovirus. We measured the percentage of GFP⁺ cells following exposure to tamoxifen or ethanol control by flow cytometry. This graph shows the ratio of tamoxifen-treated to control EtOH-treated GFP percentage for each sample. Average and standard deviation of triplicate experiments are shown. (B) Notch-induced growth inhibition in 2 human biphenotypic MLL-translocated ALL cell lines. Graph represents mean and standard deviation from triplicate experiments. The P values are from repeated measures ANOVA. (C) Decrease in cycling cells by DRAQ5 staining for DNA content in ICN1 and vector-transduced SEM-K2 cells on days 2, 4, 6, and 8 after transduction. Dotted lines represent untransduced (GFP^-) cells, solid lines represent transduced (GFP⁺) cells. (D) Percentages of cells in stages of cell cycle (G₀/G₁, S, G₂/M) from panel C. Day 0 is pretransduction. Untransduced cells (GFP^-) are shown in open symbols. Transduced cells (GFP⁺) are shown in solid symbols. Duplicate experiments were performed with similar results.