Gene expression changes associated with progression of Irf8M-bM-^@M-^S/M-bM-^@M-^S CML-like disease into blast crisis after M-NM-2-catenin activation

ABSTRACT: Progression and disease relapse of chronic myeloid leukemia (CML) depends on leukemia-initiating cells (LIC) that resist treatment. Using mouse genetics, we observed that compound constitutive activation of M-NM-2-catenin and deletion of Irf8 results in progression of CML-like disease into fatal blast crisis, elevated leukemic potential of BCR-ABL-induced LICs, and accumulation of Imatinib-resistant LICs in GMP-like populations. We found that progression of the disease is tightly connected to the magnitude of gene expression and that activated M-NM-2-catenin enhances a pre-existing Irf8-deficient gene signature that was defined as a M-bM-^@M-^\progression specific signatureM-bM-^@M-^] (PSS). We identified M-NM-2-catenin as an amplifier of disease progression and as a critical step in the shift of CML to blast crisis. Collectively, our data uncover Irf8 as a roadblock for M-NM-2-catenin-driven leukemia and imply both factors as targets in combinatorial therapy. We used microarrays to identify the gene expression signature in GMPs underlying CML-like disease progression and identified distinct classes of up- and down-regulated genes during this process defined as a M-bM-^@M-^\progression specific signature (PSS)M-bM-^@M-^]. GMP populations were sorted from three to four independent pools of control MxCreM-bM-^@M-^SCtnnb1(Ex3)fl/+, Ctnnb1(Ex3)M-bM-^HM-^F/+, Irf8M-bM-^@M-^S/M-bM-^@M-^SCtnnb1(Ex3)fl/+ and Irf8M-bM-^@M-^S/M-bM-^@M-^SCtnnb1(Ex3)M-bM-^HM-^F/+ mice for RNA extraction and hybridization on Affymetrix Mouse 430_2 chip arrays (MG-430 PM peg arrays; Affymetrix GeneChip). Cells were sorted using FACSAria (BD Biosciences Immunocytometry Systems, San Jose, CA) flow cytometers and GMPs defined as lineage depleted LinM-bM-^@M-^S Sca-1M-bM-^@M-^Sc-Kit+CD34+FcR II/IIIhi population. All mice were treated with 400M-BM-5g polyinosinic-polycytidylic acid (poly(I:C)) (Amersham) on day 0, 3 and 5 to induce M-NM-2-catenin activation (MxCre-dependent excision of Exon3 in the M-NM-2-catenin gene). Harvesting of bone marrow cells were performed 10-14 days after the last poly(I:C) injection. We used heterozygous inducible MxCre+Ctnnb1(Ex3)fl/+ mice because of the dominant effect from a single activated Ctnnb1 allele. To validate excision efficiency, genomic DNA from harvested cells was subjected to PCR, as previously described (Huelsken et al., 2001; Scheller et al., 2006).

ORGANISM(S): Mus musculus

SUBMITTER: Marina Scheller 

PROVIDER: E-GEOD-49054 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress