The regulatory interaction of EVI1 with the TCL1A oncogene impacts cell survival and clinical outcome in CLL.
Dysregulated T-cell leukemia/lymphoma-1A (TCL1A), a modulator in B-cell receptor (BCR) signaling, is causally implicated in chronic lymphocytic leukemia (CLL). However, the mechanisms of the perturbed TCL1A regulation are largely unknown. To characterize TCL1A-upstream networks, we functionally screened for TCL1A-repressive micro-RNAs (miRs) and their transcriptional regulators. We identified the novel miR-484 to target TCL1A's 3'-UTR and to be downregulated in CLL. In chromatin immunoprecipitations and reporter assays, the oncogenic transcription factor of myeloid cells, EVI1, bound and activated the miR-484 promoter. Most common in CLL was a pan-EVI1 transcript variant. EVI1 protein expression revealed distinct normal-tissue and leukemia-associated patterns of EVI1/TCL1A co-regulation. EVI1 levels were particularly low in TCL1A-high CLL or such cellular subsets. Global gene expression profiles from a 337-patient set linked EVI1 networks to BCR signaling and cell survival via TCL1A, BTK and other molecules of relevance in CLL. Enforced EVI1, as did miR-484, repressed TCL1A. Furthermore, it reduced phospho-kinase levels, impaired cell survival, mitigated BCR-induced Ca-flux and diminished the in vitro ibrutinib response. Moreover, TCL1A and EVI1 showed a strongly interactive hazard prediction in prospectively treated patients. Overall, we present regressive EVI1 as a novel regulatory signature in CLL. Through enhanced TCL1A and other EVI1-targeted hallmarks of CLL, this contributes to an aggressive cellular and clinical phenotype.
Department I of Internal Medicine, Center for Integrated Oncology Cologne-Bonn, and Excellence Cluster for Cellular Stress Response in Aging-Associated Diseases, University of Cologne, Cologne, Germany.
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E
Vasyutina
Department I of Internal Medicine, Center for Integrated Oncology Cologne-Bonn, and Excellence Cluster for Cellular Stress Response in Aging-Associated Diseases, University of Cologne, Cologne, Germany.
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JM
Boucas
Department of Internal Medicine III, Ulm University, Ulm, Germany.
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J
Bloehdorn
Department I of Internal Medicine, Center for Integrated Oncology Cologne-Bonn, and Excellence Cluster for Cellular Stress Response in Aging-Associated Diseases, University of Cologne, Cologne, Germany.
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C
Aszyk
Department I of Internal Medicine, Center for Integrated Oncology Cologne-Bonn, and Excellence Cluster for Cellular Stress Response in Aging-Associated Diseases, University of Cologne, Cologne, Germany.
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G
Crispatzu
Department I of Internal Medicine, Center for Integrated Oncology Cologne-Bonn, and Excellence Cluster for Cellular Stress Response in Aging-Associated Diseases, University of Cologne, Cologne, Germany.
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M
Stiefelhagen
Department I of Internal Medicine, Center for Integrated Oncology Cologne-Bonn, and Excellence Cluster for Cellular Stress Response in Aging-Associated Diseases, University of Cologne, Cologne, Germany.
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A
Breuer
Department I of Internal Medicine, Center for Integrated Oncology Cologne-Bonn, and Excellence Cluster for Cellular Stress Response in Aging-Associated Diseases, University of Cologne, Cologne, Germany.
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P
Mayer
Department of Hematology and Oncology, University of Tübingen Medical Center II, Tübingen, Germany.
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C
Lengerke
Department of Internal Medicine III, Ulm University, Ulm, Germany.
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H
Döhner
Department of Otorhinolaryngology, Head and Neck Surgery, University of Cologne, Cologne, Germany.
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D
Beutner
Institute of Pathology, University of Würzburg, Würzburg, Germany.
A
A
Rosenwald
Department of Internal Medicine III, Ulm University, Ulm, Germany.
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S
Stilgenbauer
Department I of Internal Medicine, Center for Integrated Oncology Cologne-Bonn, and Excellence Cluster for Cellular Stress Response in Aging-Associated Diseases, University of Cologne, Cologne, Germany.
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M
Hallek
Division of Biostatistics, German Cancer Research Center, Heidelberg, Germany.
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A
Benner
Department I of Internal Medicine, Center for Integrated Oncology Cologne-Bonn, and Excellence Cluster for Cellular Stress Response in Aging-Associated Diseases, University of Cologne, Cologne, Germany.
M
M
Herling
D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D016022:Case-Control Studies; D049109:Cell Proliferation; D047369:Chromatin Immunoprecipitation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D007124:Immunoenzyme Techniques; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics* / Q000401:mortality* / Q000473:pathology; D000074008:MDS1 and EVI1 Complex Locus Protein; D035683:MicroRNAs / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D011519:Proto-Oncogenes / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D015996:Survival Rate; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D000074008:MDS1 and EVI1 Complex Locus Protein; C063575:MECOM protein, human; C572386:MIRN484 microRNA, human; D035683:MicroRNAs; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; C090851:TCL1A protein, human; D014157:Transcription Factors