In addition, the leukemic cells occurring during blast crisis of one of our patients displayed the typical features of a stem cell leukemia (CD34+, CD19-, CD2-, myeloperoxidase-).
FAS/APO-1 antigen was expressed by the cells of 34% of the pts in CML blast crisis (BC) and directly correlated with the the expression of CD34, CD13 and CD14 differentiation antigens.
The down-regulation of DNA-PKcs was reversible in CD34(+) CML cells suggesting that this approach might offer a novel and powerful therapeutic strategy in this disease, especially to delay the blast crisis.(Blood.2001;97:2084-2090)
It was similar in leukocytes and CD34(+) cells from healthy persons (n = 44) and patients with CML in chronic phase (CP; n = 60) but significantly increased in patients with CML in blast crisis (BC; n = 20) (P <.0001).
Significantly, treatment with SAHA also down-regulated Bcr-Abl levels and induced apoptosis of CD34(+) leukemia blast progenitor cells derived from patients who had developed progressive blast crisis (BC) of chronic myelocytic leukemia (CML) while receiving therapy with imatinib.
Analysis of leukemic blasts from patients with acute lymphoblastic leukemia, acute myeloid leukemia, and chronic myeloid leukemia in blast crisis revealed that CDCP1 is predominantly expressed on CD34(+)CD133+ myeloid leukemic blasts.
We investigate here whether a feature of disease progression (i.e., elevated expression of Bcr-Abl in CD34+ progenitor cells from CML patients in blast crisis) has any bearing on the kinetics of resistance to imatinib.
Absence of the JAK2 mutation V617F in CD34+ hematopoietic stem and progenitor cells from patients with BCR-ABL-positive CML in chronic phase and blast crisis.
As a result, altered expression/function of RBPs leads to increased resistance to apoptotic stimuli, enhanced survival, growth advantage, and differentiation arrest of CD34+ progenitors from patients in CML blast crisis.
Moreover, strong antiproliferative effects of PHA-739358 were observed in CD34(+) cells derived from untreated CML patients and from IM-resistant individuals in chronic phase or blast crisis, including those harboring the T315I mutation.
Upon C/EBPalpha activation, expression of c-Myb and GATA-2 was repressed in 32D-BCR/ABL, K562, and chronic myelogenous leukemia (CML) blast crisis (BC) primary cells but only c-Myb levels decreased slightly in CD34(+) normal progenitors.
Triptolide induces cell death independent of cellular responses to imatinib in blast crisis chronic myelogenous leukemia cells including quiescent CD34+ primitive progenitor cells.
Molecular or pharmacologic interference with SK-1/S1P2 restored PP2A-dependent Bcr-Abl1 dephosphorylation, and enhanced imatinib- or nilotinib-induced growth inhibition in primary CD34(+) mononuclear cells obtained from chronic phase and blast crisis CML patients, K562/IMA-3 or LAMA4/IMA cells, and 32Dcl3 murine progenitor cells, expressing the wild-type or mutant (Y253H or T315I) Bcr-Abl1 in situ.
We further demonstrate that ropivacaine induces apoptosis and inhibits colony formation in CD34 progenitor or stem cells derived from patients with blast phase-CML.