Primitive interleukin 3 null hematopoietic cells transduced with BCR-ABL show accelerated loss after culture of factor-independence in vitro and leukemogenic activity in vivo

Growth autonomy and lineage switching in BCR-ABL-transduced human cord blood cells depend on different functional domains of BCR-ABL

“…Regardless of the final explanation, our present findings with the P210DSH2 mutant re-emphasize the importance of the cellular context in which the consequences of BCR-ABL expression are investigated, as confirmed for other downstream effects of p210 BCR-ABL . 26,27,41 As additionally demonstrated here, this includes the failure of P210 BCR-ABL to activate production of GM-CSF in primitive human hematopoietic cells in contrast to their murine counterparts. 25,27 We also documented an enhanced production of Epo transcripts in naïve human progenitors forced to express p210 BCR-ABL and showed that this response was dependent on the kinase activity of this oncoprotein.…”

“…To date, the use of this approach has been limited, but perturbations in the adhesive properties of the transduced cells 30 and their lineage commitment 31 have been documented in transduced human cord blood (CB) cells. Here we show that these cells, like their murine counterparts, 27 rapidly acquire a growth factor-independent phenotype concomitant with the activation of IL-3, G-CSF and Epo expression. In addition, we show that inhibition of the SH1 (kinase) domain and deletion of the SH2 domain of p210 BCR-ABL have different effects on the BCR-ABL-induced perturbations of growth and differentiation exhibited by primitive human hematopoietic cells immediately post-transduction.…”

“…29 However, more recent experiments with the same model showed that the generation of leukemia was critically dependent on the persistence of an autocrine IL-3 mechanism when the production of other growth factors was attenuated by short-term passage of the BCR-ABLtransduced cells in culture prior to the transplantation of reduced numbers of leukemic stem cells. 27 We have also obtained evidence of an enhanced production of erythropoietin (Epo) transcripts in primary human CML progenitors (Jiang X, Fujisaki T, Berger M, Eaves A, Eaves C. Blood 1998; 92 (Suppl. 1): 254 (abstract)), which could contribute to the observed ability of some terminally differentiating CML erythroid precursors to mature in vitro in the absence of added Epo.…”

“…27 The MSCV-BCR-ABLDSH2-IRES-GFP vector (P210DSH2) containing a mutant (SH2-deleted) BCR-ABL cDNA (from R Van Etten, Center for Blood Research, Boston, MA, USA) was constructed by replacing the original BCR-ABL cDNA with the mutant cDNA in the same vector and was further verified by restriction enzyme digestion analysis (Figure 1). Virus preparations were obtained by transfecting amphotropic Phoenix packaging cells 32 cultured in DMEM plus 10% fetal calf serum (FCS, StemCell Technologies, Vancouver, BC, Canada) using CaPO 4 .…”

“…[17][18][19][20] At the level of primitive CML progenitors, this abnormal behavior is due, at least in part, to the acquisition by the neoplastic cells of an autocrine interleukin-3 (IL-3)/granulocyte colony-stimulating factor (G-CSF) growth mechanism. 21 P210 BCR-ABL -induced production of IL-3 by hematopoietic cells was first demonstrated in various immortalized, factor-dependent cell lines, [22][23][24] and later confirmed in BCR-ABL-transduced primary mouse BM cells [25][26][27] and embryonic stem cells. 28 A subsequent study showed that the lethal leukemias obtained following the transplantation of large numbers of BCR-ABLtransduced IL3 À/À or granulocyte-macrophage colony-stimulating factor (GM-CSF) À/À mouse BM cells raised questions about the importance of autocrine factor production to the leukemogenic potential of primitive CML cells.…”