EVI1 is critical for the pathogenesis of a subset of MLL-AF9-rearranged AMLs
ABSTRACT The proto-oncogene EVI1 (ecotropic viral integration site-1), located on chromosome band 3q26, is aberrantly expressed in human acute myeloid leukemia (AML) with 3q26 rearrangements. In the current study, we showed, in a large AML cohort carrying 11q23 translocations, that ∼ 43% of all mixed lineage leukemia (MLL)-rearranged leukemias are EVI1(pos). High EVI1 expression occurs in AMLs expressing the MLL-AF6, -AF9, -AF10, -ENL, or -ELL fusion genes. In addition, we present evidence that EVI1(pos) MLL-rearranged AMLs differ molecularly, morphologically, and immunophenotypically from EVI1(neg) MLL-rearranged leukemias. In mouse bone marrow cells transduced with MLL-AF9, we show that MLL-AF9 fusion protein maintains Evi1 expression on transformation of Evi1(pos) HSCs. MLL-AF9 does not activate Evi1 expression in MLL-AF9-transformed granulocyte macrophage progenitors (GMPs) that were initially Evi1(neg). Moreover, shRNA-mediated knockdown of Evi1 in an Evi1(pos) MLL-AF9 mouse model inhibits leukemia growth both in vitro and in vivo, suggesting that Evi1 provides a growth-promoting signal. Using the Evi1(pos) MLL-AF9 mouse leukemia model, we demonstrate increased sensitivity to chemotherapeutic agents on reduction of Evi1 expression. We conclude that EVI1 is a critical player in tumor growth in a subset of MLL-rearranged AMLs.
- SourceAvailable from: Yi Zhang
[Show abstract] [Hide abstract]
- "The ecotropic virus integration site 1 (EVI1) is an oncogenic transcription factor associated with human myeloid malignancy and several solid epithelial cancers , , . Aberrant EVI1 expression occurs in 8–10% of human adult acute myeloid leukemia (AML) and strikingly up to 27% of pediatric mixed lineage leukemia (MLL) rearranged leukemias . EVI1 is one of several protein isoforms encoded by the MECOM locus at human chromosome 3q26 which also yields the MDS1 and MDS-EVI1 protein isoforms . "
ABSTRACT: The ecotropic virus integration site 1 (EVI1) transcription factor is associated with human myeloid malignancy of poor prognosis and is overexpressed in 8-10% of adult AML and strikingly up to 27% of pediatric MLL-rearranged leukemias. For the first time, we report comprehensive genomewide EVI1 binding and whole transcriptome gene deregulation in leukemic cells using a combination of ChIP-Seq and RNA-Seq expression profiling. We found disruption of terminal myeloid differentiation and cell cycle regulation to be prominent in EVI-induced leukemogenesis. Specifically, we identified EVI1 directly binds to and downregulates the master myeloid differentiation gene Cebpe and several of its downstream gene targets critical for terminal myeloid differentiation. We also found EVI1 binds to and downregulates Serpinb2 as well as numerous genes involved in the Jak-Stat signaling pathway. Finally, we identified decreased expression of several ATP-dependent P2X purinoreceptors genes involved in apoptosis mechanisms. These findings provide a foundation for future study of potential therapeutic gene targets for EVI1-induced leukemia.PLoS ONE 06/2013; 8(6):e67134. DOI:10.1371/journal.pone.0067134 · 3.23 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: PURPOSETo evaluate the prognostic value of ecotropic viral integration 1 gene (EVI1) overexpression in acute myeloid leukemia (AML) with MLL gene rearrangements. PATIENTS AND METHODS We identified 286 patients with AML with t(11q23) enrolled onto German-Austrian Acute Myeloid Leukemia Study Group and Dutch-Belgian-Swiss Hemato-Oncology Cooperative Group prospective treatment trials. Material was available from 177 AML patients for EVI1 expression analysis. RESULTS: t(9;11)(p22;q23) (44.8%), t(6;11)(q27;q23) (14.7%), and t(v;11q23) (40.5%). EVI1 overexpression (EVI1(+)) was found in 45.8% of all patients with t(11q23), with t(6;11) showing the highest frequency (83.9%), followed by t(9;11) at 40.0%, and t(v;11q23) at 34.8%. Concurrent gene mutations were rare or absent in all three subgroups. Within all t(11q23) AMLs, EVI1(+) was the sole prognostic factor, predicting for inferior overall survival (OS; hazard ratio [HR], 2.06; P = .003), relapse-free survival (HR, 2.28; P = .002), and event-free survival (HR, 1.79; P = .009). EVI1(+) AMLs with t(11q23) in first complete remission (CR) had a significantly better outcome after allogeneic transplantation compared with other consolidation therapies (5-year OS, 54.7% v 0%; Mantel-Byar, P = .0006). EVI1(-) t(9;11) AMLs had lower WBC counts, more commonly FAB M5 morphology, and frequently had additional trisomy 8 (39.6%; P < .001). Among t(9;11) AMLs, EVI1(+) again was the sole independent adverse prognostic factor for survival. CONCLUSION Deregulated EVI1 expression defines poor prognostic subsets among AML with t(11q23) and AML with t(9;11)(p22;q23). Patients with EVI1(+) MLL-rearranged AML seem to benefit from allogeneic transplantation in first CR.Journal of Clinical Oncology 09/2012; 31(1). DOI:10.1200/JCO.2011.41.5505 · 18.43 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: MLL-fusion proteins can induce acute myeloid leukemias (AML) from either hematopoietic stem cells (HSC) or granulocyte macrophage progenitors (GMP), but it remains unclear if the cell of origin influences the biology of the resultant leukemia. MLL-AF9 transduced single HSC or GMP could be continuously replated, but HSC-derived clones were more likely than GMP-derived clones to initiate AML in mice. Leukemia stem cells derived from either HSC or GMP had a similar immunophenotype consistent with a maturing myeloid cell (LGMP). Gene expression analyses demonstrated that LGMP inherited gene expression programs from the cell of origin including high-level Evi-1 expression in HSC derived LGMP. The gene expression signature of LGMP derived from HSC was enriched in poor prognosis human MLL-rearranged AML in three independent data sets. Moreover, global 5'-mC levels were elevated in HSC-derived leukemias as compared to GMP-derived leukemias. This mirrored a difference seen in 5-mC between MLL-rearranged human leukemias that are either EVI1-positive or EVI1-negative. Finally, HSC derived leukemias were more resistant to chemotherapy than GMP-derived leukemias. These data demonstrate that the cell of origin influences the gene expression profile, the epigenetic state, and the drug response in AML, and that these differences can account for clinical heterogeneity within a molecularly defined group of leukemias.Leukemia accepted article preview online, 13 December 2012; doi:10.1038/leu.2012.363.Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 12/2012; 27(4). DOI:10.1038/leu.2012.363 · 10.43 Impact Factor