Role of A1 in the BCR/ABL-mediated leukemogenesis.

(A, left panel) 32DHN control cells and cells expressing A1 protein (32DHN-A1) were infected with the retrovirus carrying BCR/ABL WT-IRES-GFP, BCR/ABLΔΔ-IRES-GFP, or IRES-GFP. BCR/ABL and A1 proteins were detected in growth factor–starved GFP⁺ cells by Western analysis. Actin was detected as control for protein loading. (A, right panel) Cells were incubated in the absence of IL-3 for 5 days and apoptosis was detected by the in vitro apoptosis detection test. (B) 32Dcl3 cells expressing BCR/ABL were infected with retrovirus carrying A1 AS cDNA-IRES-GFP or with empty (E) retrovirus. GFP⁺ cells were analyzed for the expression of A1 protein (upper box) and actin (lower box). Apoptosis was examined in the absence of IL-3 (squares) or in the absence of IL-3 and serum (triangles). Results represent 4 experiments.