Multiplex CRISPR/Cas9-Based Genome Editing of Mouse Hematopoietic Stem Cells Recapitulates Acute Erythroid Leukemia and Identifies Therapeutic Targets [RNA-Seq]

ABSTRACT: Acute erythroid leukemia (AEL) is a high-risk leukemia with a distinct mutational spectrum. Here, we examined the cooperativity of loss of function alterations in leukemogenesis and tested the therapeutic tractability of each model of AEL. Using CRISPR/Cas9 genome editing, we generated six pools of lentiviral vectors with different combinations of guide RNAs and transduced Cas9-eGFP-mouse mouse hematopoietic stem and progenitor cells (HSPCs) that were used in transplant assays. Induced tumors were characterized by phenotype, genomic/epigenomic analysis and tested for sensitivity to 222 therapeutic agents. Tumor genotype determined tumor phenotype with Bcor and Tp53 driving erythroid leukemogenesis. Tumors showed acquisition of additional somatic mutations during serial passaging and by transcriptomic analysis AEL models had overexpression of transcription factors required for differentiation of megakaryocyte-erythroid progenitors and recapitulated human AEL. Dnmt3a-mutated models exhibited global hypomethylation, but hypermethylation when co-occurred with Tet2 mutations. Drug response was associated with genotype. Tp53 wild-type but Dnmt3a/Tet2 double mutant cells were the most chemo-sensitive models. ViceversaTp53-mutated AEL subtypes were chemo-resistant to several conventional chemotherapeutics but highly sensitivity to PARP inhibitors, including talazoparib. Sensitivity to talazoparib was confirmed in vivo when combined with decitabine. In conclusion, combinations of recurrently mutated genes are critical determinants of leukemia phenotype, with central roles of Tp53 and Bcor mutations in driving the erythroid leukemogenesis. Using these models as preclinical tools, we have shown the potential for bromodomain and PARP inhibition as new therapeutic strategies in AEL.

ORGANISM(S): Mus musculus

PROVIDER: GSE147265 | GEO | 2021/02/10

REPOSITORIES: GEO