ABT-737 treatment induces regulation and activation of pathways implicated in cell survival, proliferation and stem cells in treated AML mice survival, proliferation and stem cells in treated AML mice

ABSTRACT: Myelodysplastic syndrome (MDS) transforms into an acute myelogenous leukemia (AML) with associated increased bone marrow blast infiltration. Using a transgenic mouse model, MRP8[NRASD12/hBCL-2], in which the NRAS:BCL-2 complex at the mitochondria induces MDS progressing to AML with dysplastic features, we studied the therapeutic potential of a BCL-2 homology domain 3 (BH3) mimetic inhibitor, ABT-737. Treatment significantly extended lifespan, increased survival of lethally irradiated secondary recipients transplanted with treated cells compared with cells from untreated mice, with a reduction of bone marrow (BM) blasts, LSK and progenitor populations by increased apoptosis of infiltrating blasts of diseased mice assessed in vivo by Tc-99m-labeled Annexin V single photon emission computed tomography (SPECT) and ex vivo by Annexin V/7AAD flow cytometry, TUNEL, caspase 3 cleavage and re-localization of the NRAS:BCL-2 complex from mitochondria to plasma membrane. Phosphoprotein analysis showed restoration of wild-type AKT, ERK1/2 and MEK patterns in spleen cells after treatment, which show reduced mitochondrial membrane potential. Exon specific gene expression profiling corroborates the reduction of leukemic cells, with an increase in expression of genes coding for stem cell development and maintenance, myeloid differentiation and apoptosis. Myelodysplastic features persist underscoring targeting of BCL-2-mediated effects on MDS-AML transformation and survival of leukemic cells. NRASD12/BCL-2 double transgenic mice were analysed by enriching for primitive Sca1+ cells from splenocytes from untreated and ABT-737 treated mice. RNA was extracted analysed for gene expression profiles using exon specific arrays.

ORGANISM(S): Mus musculus

SUBMITTER: Pierre de la Grange 

PROVIDER: E-GEOD-48601 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress