Table 1.

Effect of p53 expression on the number of colonies derived from BMCs after infection with BCR/ABL

Virus	Cells	Primary culture		Secondary culture
		IL-3 +	IL-3 −	IL-3 +	IL-3 −
E	+/+	23  ± 7	0	13  ± 3	—
E	−/−	27  ± 10	0	20  ± 6	—
BCR/ABL	+/+	89  ± 17	4  ± 1	86  ± 12	2  ± 1
BCR/ABL	−/−	376  ± 68	28  ± 2	887  ± 154	26  ± 8
BCR/ABL[1172]	+/+	32  ± 15	0	11  ± 4	—
BCR/ABL[1172]	−/−	34  ± 9	0	16  ± 3	—
E + p53[WT]	−/−	24  ± 3	0	15  ± 7	—
BCR/ABL + p53[WT]	−/−	74  ± 10	3  ± 2	81  ± 7	1  ± 2

BMCs from p53^+/+ or p53^−/− mice were infected with BCR/ABL, BCR/ABL[1172R] mutant, p53 wild-type (p53[WT]), or insert-less (E) retroviral constructs. After 14 days in liquid culture with G418, 10⁵ cells were plated in G418-containing semisolid medium for 12 days (primary colonies) in the presence or absence of threshold concentrations (0.1 unit/ml) of recombinant murine IL-3. For secondary colony assays, 10 large colonies from each group growing in the absence of IL-3 were plucked individually and 50 cells from each colony were plated. From colonies grown in the presence of IL-3, 10⁴ cells were replated in threshold concentrations of IL-3 in the presence of G418. Colonies were counted 9 to 12 days later. Results represent mean ± SD from 3–4 experiments.