RESUMEN
Kinase signaling fuels growth of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Yet its role in leukemia initiation is unclear and has not been shown in primary human hematopoietic cells. We previously described activating mutations in interleukin-7 receptor alpha (IL7RA) in poor-prognosis "ph-like" BCP-ALL. Here we show that expression of activated mutant IL7RA in human CD34+ hematopoietic stem and progenitor cells induces a preleukemic state in transplanted immunodeficient NOD/LtSz-scid IL2Rγnull mice, characterized by persistence of self-renewing Pro-B cells with non-productive V(D)J gene rearrangements. Preleukemic CD34+CD10highCD19+ cells evolve into BCP-ALL with spontaneously acquired Cyclin Dependent Kinase Inhibitor 2 A (CDKN2A) deletions, as commonly observed in primary human BCP-ALL. CRISPR mediated gene silencing of CDKN2A in primary human CD34+ cells transduced with activated IL7RA results in robust development of BCP-ALLs in-vivo. Thus, we demonstrate that constitutive activation of IL7RA can initiate preleukemia in primary human hematopoietic progenitors and cooperates with CDKN2A silencing in progression into BCP-ALL.
Asunto(s)
Subunidad alfa del Receptor de Interleucina-7/inmunología , Leucemia-Linfoma Linfoblástico de Células Precursoras B/inmunología , Células Precursoras de Linfocitos B/inmunología , Transducción de Señal/inmunología , Animales , Antígenos CD34/genética , Antígenos CD34/inmunología , Antígenos CD34/metabolismo , Secuencia de Bases , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/inmunología , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Expresión Génica/inmunología , Humanos , Subunidad alfa del Receptor de Interleucina-7/genética , Subunidad alfa del Receptor de Interleucina-7/metabolismo , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Células Precursoras de Linfocitos B/metabolismo , RNA-Seq/métodos , Receptores de Citocinas/genética , Receptores de Citocinas/inmunología , Receptores de Citocinas/metabolismo , Transducción de Señal/genética , Análisis de la Célula Individual/métodos , Trasplante HeterólogoRESUMEN
Comparison of intratumor genetic heterogeneity in cancer at diagnosis and relapse suggests that chemotherapy induces bottleneck selection of subclonal genotypes. However, evolutionary events subsequent to chemotherapy could also explain changes in clonal dominance seen at relapse. We, therefore, investigated the mechanisms of selection in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) during induction chemotherapy where maximal cytoreduction occurs. To distinguish stochastic versus deterministic events, individual leukemias were transplanted into multiple xenografts and chemotherapy administered. Analyses of the immediate post-treatment leukemic residuum at single-cell resolution revealed that chemotherapy has little impact on genetic heterogeneity. Rather, it acts on extensive, previously unappreciated, transcriptional and epigenetic heterogeneity in BCP-ALL, dramatically reducing the spectrum of cell states represented, leaving a genetically polyclonal but phenotypically uniform population with hallmark signatures relating to developmental stage, cell cycle and metabolism. Hence, canalization of cell state accounts for a significant component of bottleneck selection during induction chemotherapy.
Asunto(s)
Linfoma de Burkitt , Leucemia-Linfoma Linfoblástico de Células Precursoras , Linfoma de Burkitt/tratamiento farmacológico , Ciclo Celular , Humanos , Quimioterapia de Inducción , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , RecurrenciaRESUMEN
ETV6-RUNX1 is associated with childhood acute B-lymphoblastic leukemia (cALL) functioning as a first-hit mutation that initiates a clinically silent pre-leukemia in utero. Because lineage commitment hierarchies differ between embryo and adult, and the impact of oncogenes is cell-context dependent, we hypothesized that the childhood affiliation of ETV6-RUNX1 cALL reflects its origins in a progenitor unique to embryonic life. We characterize the first emerging B cells in first-trimester human embryos, identifying a developmentally restricted CD19-IL-7R+ progenitor compartment, which transitions from a myeloid to lymphoid program during ontogeny. This developmental series is recapitulated in differentiating human pluripotent stem cells (hPSCs), thereby providing a model for the initiation of cALL. Genome-engineered hPSCs expressing ETV6-RUNX1 from the endogenous ETV6 locus show expansion of the CD19-IL-7R+ compartment, show a partial block in B lineage commitment, and produce proB cells with aberrant myeloid gene expression signatures and potential: features (collectively) consistent with a pre-leukemic state.
Asunto(s)
Linfocitos B/patología , Subunidad alfa 2 del Factor de Unión al Sitio Principal/metabolismo , Desarrollo Embrionario , Regulación Leucémica de la Expresión Génica , Células Madre Pluripotentes Inducidas/patología , Células Mieloides/patología , Proteínas de Fusión Oncogénica/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Enfermedad Aguda , Linfocitos B/metabolismo , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Femenino , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Modelos Biológicos , Células Mieloides/metabolismo , Proteínas de Fusión Oncogénica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Embarazo , Primer Trimestre del Embarazo , Receptores de Interleucina-7 , TranscriptomaRESUMEN
Tumor relapse is associated with dismal prognosis, but responsible biological principles remain incompletely understood. To isolate and characterize relapse-inducing cells, we used genetic engineering and proliferation-sensitive dyes in patient-derived xenografts of acute lymphoblastic leukemia (ALL). We identified a rare subpopulation that resembled relapse-inducing cells with combined properties of long-term dormancy, treatment resistance, and stemness. Single-cell and bulk expression profiling revealed their similarity to primary ALL cells isolated from pediatric and adult patients at minimal residual disease (MRD). Therapeutically adverse characteristics were reversible, as resistant, dormant cells became sensitive to treatment and started proliferating when dissociated from the in vivo environment. Our data suggest that ALL patients might profit from therapeutic strategies that release MRD cells from the niche.