Figure 3. The secondary transplantation of AAFP-induced leukemia and the leukemia maintaining subpopulation.

(A) For the induction of secondary leukemia, frozen samples from primary leukemic mice were inoculated into sublethally irradiated mice. Frozen spleen cells isolated from primary leukemia induced by the indicated AAFPs and derived from LT-HSC, as described previously, were inoculated into sublethally irradiated recipient mice. The survival curves show the recipients succumbing to disease after receiving 2×10⁴ cells/mouse. (B) Fresh spleen cells from secondary leukemic mice were sorted based on the expression of c-Kit, Sca1, Flk2 and the lineage markers (MP, LT- and ST-HSC) or of B220 and the myeloid markers Mac1 and Gr1. The sorted cell populations were then inoculated into sublethally irradiated recipient mice to determine the leukemogenic potential of the sorted subpopulations. The sorting protocol is shown for the indicated subpopulations within the secondary PML/RARα-positive leukemia (C) The survival curves of recipients succumbing to disease after receiving the sorted subpopulations. (D) Expression of PML/RARα in mice harboring secondary (II) leukemia and leukemia from the MP and the indicated subpopulations, as determined by Western blot. (E) Morphological and histological analysis of samples from secondary leukemia or leukemia from the indicated subpopulations.