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Manuelyan K, Momcheva I, Angelova S, Nikolov K, Shivarov V. Recurrent ETV6::SYK rearrangement in myeloid malignancies confers partial susceptibility to MEK inhibition. Br J Haematol 2024. [PMID: 38763512 DOI: 10.1111/bjh.19549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 05/10/2024] [Indexed: 05/21/2024]
Affiliation(s)
- Karen Manuelyan
- Department of Dermatology and Venereology, Medical Faculty, Trakia University and UMHAT "Prof. Dr. St. Kirkovich", Stara Zagora, Bulgaria
| | - Irina Momcheva
- Department of Rheumatology Burgas, University "Prof. Dr. Asen Zlatarov" Burgas and UMHAT Burgas, Burgas, Bulgaria
| | - Svetlana Angelova
- Laboratory of Cytogenetics and Molecular Biology, National Haematology Hospital, Sofia, Bulgaria
| | - Krasimir Nikolov
- Department of Medical Oncology, Complex Oncology Center, Burgas, Bulgaria
| | - Velizar Shivarov
- Department of Experimental Research, Medical University Pleven, Pleven, Bulgaria
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2
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Kinnunen M, Liu X, Niemelä E, Öhman T, Gawriyski L, Salokas K, Keskitalo S, Varjosalo M. The Impact of ETV6-NTRK3 Oncogenic Gene Fusions on Molecular and Signaling Pathway Alterations. Cancers (Basel) 2023; 15:4246. [PMID: 37686522 PMCID: PMC10486691 DOI: 10.3390/cancers15174246] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 08/10/2023] [Accepted: 08/17/2023] [Indexed: 09/10/2023] Open
Abstract
Chromosomal translocations creating fusion genes are common cancer drivers. The oncogenic ETV6-NTRK3 (EN) gene fusion joins the sterile alpha domain of the ETV6 transcription factor with the tyrosine kinase domain of the neurotrophin-3 receptor NTRK3. Four EN variants with alternating break points have since been detected in a wide range of human cancers. To provide molecular level insight into EN oncogenesis, we employed a proximity labeling mass spectrometry approach to define the molecular context of the fusions. We identify in total 237 high-confidence interactors, which link EN fusions to several key signaling pathways, including ERBB, insulin and JAK/STAT. We then assessed the effects of EN variants on these pathways, and showed that the pan NTRK inhibitor Selitrectinib (LOXO-195) inhibits the oncogenic activity of EN2, the most common variant. This systems-level analysis defines the molecular framework in which EN oncofusions operate to promote cancer and provides some mechanisms for therapeutics.
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Affiliation(s)
- Matias Kinnunen
- Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
- Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Xiaonan Liu
- Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
- Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Elina Niemelä
- Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
- Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Tiina Öhman
- Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
- Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Lisa Gawriyski
- Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
- Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Kari Salokas
- Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
- Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Salla Keskitalo
- Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
- Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Markku Varjosalo
- Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
- Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
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Sivakumar S, Moore JA, Montesion M, Sharaf R, Lin DI, Colón CI, Fleishmann Z, Ebot EM, Newberg JY, Mills JM, Hegde PS, Pan Q, Dowlati A, Frampton GM, Sage J, Lovly CM. Integrative Analysis of a Large Real-World Cohort of Small Cell Lung Cancer Identifies Distinct Genetic Subtypes and Insights into Histologic Transformation. Cancer Discov 2023; 13:1572-1591. [PMID: 37062002 PMCID: PMC10326603 DOI: 10.1158/2159-8290.cd-22-0620] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 03/08/2023] [Accepted: 04/06/2023] [Indexed: 04/17/2023]
Abstract
Small cell lung cancer (SCLC) is a recalcitrant neuroendocrine carcinoma with dismal survival outcomes. A major barrier in the field has been the relative paucity of human tumors studied. Here we provide an integrated analysis of 3,600 "real-world" SCLC cases. This large cohort allowed us to identify new recurrent alterations and genetic subtypes, including STK11-mutant tumors (1.7%) and TP53/RB1 wild-type tumors (5.5%), as well as rare cases that were human papillomavirus-positive. In our cohort, gene amplifications on 4q12 are associated with increased overall survival, whereas CCNE1 amplification is associated with decreased overall survival. We also identify more frequent alterations in the PTEN pathway in brain metastases. Finally, profiling cases of SCLC containing oncogenic drivers typically associated with NSCLC demonstrates that SCLC transformation may occur across multiple distinct molecular cohorts of NSCLC. These novel and unsuspected genetic features of SCLC may help personalize treatment approaches for this fatal form of cancer. SIGNIFICANCE Minimal changes in therapy and survival outcomes have occurred in SCLC for the past four decades. The identification of new genetic subtypes and novel recurrent mutations as well as an improved understanding of the mechanisms of transformation to SCLC from NSCLC may guide the development of personalized therapies for subsets of patients with SCLC. This article is highlighted in the In This Issue feature, p. 1501.
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Affiliation(s)
| | - Jay A. Moore
- Foundation Medicine, Inc., Cambridge, Massachusetts
| | | | - Radwa Sharaf
- Foundation Medicine, Inc., Cambridge, Massachusetts
| | | | - Caterina I. Colón
- Departments of Pediatrics and Genetics, Stanford University, Stanford, California
| | | | | | | | | | | | - Quintin Pan
- University Hospitals Seidman Cancer Center and Case Western Reserve University, Cleveland, Ohio
| | - Afshin Dowlati
- University Hospitals Seidman Cancer Center and Case Western Reserve University, Cleveland, Ohio
| | | | - Julien Sage
- Departments of Pediatrics and Genetics, Stanford University, Stanford, California
| | - Christine M. Lovly
- Division of Hematology-Oncology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
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Hartman ML, Czyz M. BCL-G: 20 years of research on a non-typical protein from the BCL-2 family. Cell Death Differ 2023:10.1038/s41418-023-01158-5. [PMID: 37031274 DOI: 10.1038/s41418-023-01158-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 03/24/2023] [Accepted: 03/28/2023] [Indexed: 04/10/2023] Open
Abstract
Proteins from the BCL-2 family control cell survival and apoptosis in health and disease, and regulate apoptosis-unrelated cellular processes. BCL-Gonad (BCL-G, also known as BCL2-like 14) is a non-typical protein of the family as its long isoform (BCL-GL) consists of BH2 and BH3 domains without the BH1 motif. BCL-G is predominantly expressed in normal testes and different organs of the gastrointestinal tract. The complexity of regulatory mechanisms of BCL-G expression and post-translational modifications suggests that BCL-G may play distinct roles in different types of cells and disorders. While several genetic alterations of BCL2L14 have been reported, gene deletions and amplifications prevail, which is also confirmed by the analysis of sequencing data for different types of cancer. Although the studies validating the phenotypic consequences of genetic manipulations of BCL-G are limited, the role of BCL-G in apoptosis has been undermined. Recent studies using gene-perturbation approaches have revealed apoptosis-unrelated functions of BCL-G in intracellular trafficking, immunomodulation, and regulation of the mucin scaffolding network. These studies were, however, limited mainly to the role of BCL-G in the gastrointestinal tract. Therefore, further efforts using state-of-the-art methods and various types of cells are required to find out more about BCL-G activities. Deciphering the isoform-specific functions of BCL-G and the BCL-G interactome may result in the designing of novel therapeutic approaches, in which BCL-G activity will be either imitated using small-molecule BH3 mimetics or inhibited to counteract BCL-G upregulation. This review summarizes two decades of research on BCL-G.
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Affiliation(s)
- Mariusz L Hartman
- Department of Molecular Biology of Cancer, Medical University of Lodz, 6/8 Mazowiecka Street, 92-215, Lodz, Poland.
| | - Malgorzata Czyz
- Department of Molecular Biology of Cancer, Medical University of Lodz, 6/8 Mazowiecka Street, 92-215, Lodz, Poland
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ETV6 dependency in Ewing sarcoma by antagonism of EWS-FLI1-mediated enhancer activation. Nat Cell Biol 2023; 25:298-308. [PMID: 36658219 PMCID: PMC10101761 DOI: 10.1038/s41556-022-01060-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 11/24/2022] [Indexed: 01/21/2023]
Abstract
The EWS-FLI1 fusion oncoprotein deregulates transcription to initiate the paediatric cancer Ewing sarcoma. Here we used a domain-focused CRISPR screen to implicate the transcriptional repressor ETV6 as a unique dependency in this tumour. Using biochemical assays and epigenomics, we show that ETV6 competes with EWS-FLI1 for binding to select DNA elements enriched for short GGAA repeat sequences. Upon inactivating ETV6, EWS-FLI1 overtakes and hyper-activates these cis-elements to promote mesenchymal differentiation, with SOX11 being a key downstream target. We show that squelching of ETV6 with a dominant-interfering peptide phenocopies these effects and suppresses Ewing sarcoma growth in vivo. These findings reveal targeting of ETV6 as a strategy for neutralizing the EWS-FLI1 oncoprotein by reprogramming of genomic occupancy.
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Kodgule R, Goldman JW, Monovich AC, Saari T, Aguilar AR, Hall CN, Rajesh N, Gupta J, Chu SCA, Ye L, Gurumurthy A, Iyer A, Brown NA, Chiang MY, Cieslik MP, Ryan RJ. ETV6 Deficiency Unlocks ERG-Dependent Microsatellite Enhancers to Drive Aberrant Gene Activation in B-Lymphoblastic Leukemia. Blood Cancer Discov 2023; 4:34-53. [PMID: 36350827 PMCID: PMC9820540 DOI: 10.1158/2643-3230.bcd-21-0224] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 08/30/2022] [Accepted: 11/02/2022] [Indexed: 11/11/2022] Open
Abstract
Distal enhancers play critical roles in sustaining oncogenic gene-expression programs. We identify aberrant enhancer-like activation of GGAA tandem repeats as a characteristic feature of B-cell acute lymphoblastic leukemia (B-ALL) with genetic defects of the ETV6 transcriptional repressor, including ETV6-RUNX1+ and ETV6-null B-ALL. We show that GGAA repeat enhancers are direct activators of previously identified ETV6-RUNX1+/- like B-ALL "signature" genes, including the likely leukemogenic driver EPOR. When restored to ETV6-deficient B-ALL cells, ETV6 directly binds to GGAA repeat enhancers, represses their acetylation, downregulates adjacent genes, and inhibits B-ALL growth. In ETV6-deficient B-ALL cells, we find that the ETS transcription factor ERG directly binds to GGAA microsatellite enhancers and is required for sustained activation of repeat enhancer-activated genes. Together, our findings reveal an epigenetic gatekeeper function of the ETV6 tumor suppressor gene and establish microsatellite enhancers as a key mechanism underlying the unique gene-expression program of ETV6-RUNX1+/- like B-ALL. SIGNIFICANCE We find a unifying mechanism underlying a leukemia subtype-defining gene-expression signature that relies on repetitive elements with poor conservation between humans and rodents. The ability of ETV6 to antagonize promiscuous, nonphysiologic ERG activity may shed light on other roles of these key regulators in hematolymphoid development and human disease. See related commentary by Mercher, p. 2. This article is highlighted in the In This Issue feature, p. 1.
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Affiliation(s)
- Rohan Kodgule
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Joshua W. Goldman
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan
| | | | - Travis Saari
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Athalee R. Aguilar
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Cody N. Hall
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Niharika Rajesh
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Juhi Gupta
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Shih-Chun A. Chu
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Li Ye
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Aishwarya Gurumurthy
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Ashwin Iyer
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Noah A. Brown
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Mark Y. Chiang
- Department of Medicine, University of Michigan Medical School, Ann Arbor, Michigan
| | - Marcin P. Cieslik
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Russell J.H. Ryan
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
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Aepala MR, Peiris MN, Jiang Z, Yang W, Meyer AN, Donoghue DJ. Nefarious NTRK oncogenic fusions in pediatric sarcomas: Too many to Trk. Cytokine Growth Factor Rev 2022; 68:93-106. [PMID: 36153202 DOI: 10.1016/j.cytogfr.2022.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 01/30/2023]
Abstract
Neurotrophic Tyrosine Receptor Kinase (NTRK) genes undergo chromosomal translocations to create novel open reading frames coding for oncogenic fusion proteins; the N-terminal portion, donated by various partner genes, becomes fused to the tyrosine kinase domain of either NTRK1, NTRK2, or NTRK3. NTRK fusion proteins have been identified as driver oncogenes in a wide variety of tumors over the past three decades, including Pediatric Gliomas, Papillary Thyroid Carcinoma, Spitzoid Neoplasms, Glioblastoma, and additional tumors. Importantly, NTRK fusions function as drivers of pediatric sarcomas, accounting for approximately 15% of childhood cancers including Infantile Fibrosarcoma (IFS), a subset of pediatric soft tissue sarcoma (STS). While tyrosine kinase inhibitors (TKIs), such as larotrectinib and entrectinib, have demonstrated profound results against NTRK fusion-positive cancers, acquired resistance to these TKIs has resulted in the formation of gatekeeper, solvent-front, and compound mutations. We present a comprehensive compilation of oncogenic fusions involving NTRKs focusing specifically on pediatric STS, examining their biological signaling pathways and mechanisms of activation. The importance of an obligatory dimerization or multimerization domain, invariably donated by the N-terminal fusion partner, is discussed using characteristic fusions that occur in pediatric sarcomas. In addition, examples are presented of oncogenic fusion proteins in which the N-terminal partners may contribute additional biological activities beyond an oligomerization domain. Lastly, therapeutic approaches to the treatment of pediatric sarcoma will be presented, using first generation and second-generation agents such as selitrectinib and repotrectinib.
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Affiliation(s)
- Megha R Aepala
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0367, USA
| | - Malalage N Peiris
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0367, USA
| | - Zian Jiang
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0367, USA
| | - Wei Yang
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0367, USA
| | - April N Meyer
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0367, USA
| | - Daniel J Donoghue
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0367, USA; UCSD Moores Cancer Center, University of California San Diego, La Jolla, CA 92093-0367, USA.
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8
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Li Z, Sun MZ, Lv X, Guo C, Liu S. ETV6 Regulates Hemin-Induced Erythroid Differentiation of K562 Cells through Mediating the Raf/MEK/ERK Pathway. Biol Pharm Bull 2022; 45:250-259. [PMID: 35228392 DOI: 10.1248/bpb.b21-00632] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
As a member of transcription factor E-Twenty Six (ETS) family, ETS variant 6 (ETV6) plays significant role in hematopoiesis and embryonic development. ETV6 dysexpression also involved in the occurrence, development and progression of cancers and leukemia. In current work, we hypothesized that ETV6 plays a role in erythroid differentiation of chronic myeloid leukemia (CML). We found the protein expression level of ETV6 was significantly upregulated during hemin-induced erythroid differentiation of K562 cells. Moreover, overexpression of ETV6 inhibited erythroid differentiation in hemin-induced K562 cells with decreased numbers of benzidine-positive cells and decreased expression levels of erythroid differentiation specific markers glycophorin (GPA), CD71, hemoglobin A (HBA), α-globin, γ-globin and ε-globin. Conversely, ETV6 knockdown promoted erythroid differentiation in hemin-induced K562 cells. Furthermore, ETV6 expression level slightly positively with the proliferation capacity of K562 cells treated with hemin. Mechanistically, ETV6 overexpression inhibited fibrosarcoma/mitogen activated extracellular signal-regulated kinase/extracellular regulated protein kinase (Raf/MEK/ERK) pathway, ETV6 knockdown activated the Raf/MEK/ERK pathway. Collectively, the current work demonstrates that ETV6 plays an inhibitory role in the regulation of K562 cell erythroid differentiation via Raf/MEK/ERK pathway, it would be a potentially therapeutic target for dyserythropoiesis.
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Affiliation(s)
- Zhaopeng Li
- Department of Biochemistry, College of Basic Medical Sciences, Dalian Medical University
| | - Ming-Zhong Sun
- Department of Biotechnology, College of Basic Medical Sciences, Dalian Medical University
| | - Xinxin Lv
- Department of Biotechnology, College of Basic Medical Sciences, Dalian Medical University
| | - Chunmei Guo
- Department of Biotechnology, College of Basic Medical Sciences, Dalian Medical University
| | - Shuqing Liu
- Department of Biochemistry, College of Basic Medical Sciences, Dalian Medical University
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Bubola J, MacMillan CM, Weinreb I, Witterick I, Swanson D, Zhang L, Antonescu CR, Dickson BC. A Poorly Differentiated Non-keratinizing Sinonasal Squamous Cell Carcinoma with a Novel ETV6-TNFRSF8 Fusion Gene. Head Neck Pathol 2021; 15:1284-1288. [PMID: 33394379 PMCID: PMC8633219 DOI: 10.1007/s12105-020-01249-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/05/2020] [Accepted: 11/06/2020] [Indexed: 10/22/2022]
Abstract
Squamous cell carcinoma of the sinonasal tract is relatively rare and morphologically and genetically heterogeneous. We report the case of an adult male with a left sphenoid sinus mass. A biopsy revealed an undifferentiated carcinoma composed of sheets of epithelioid cells lacking keratinization and glandular formation. The tumor was associated with a prominent lymphoplasmacytic inflammatory infiltrate. Immunohistochemical staining demonstrated diffuse expression of pankeratin and p63; it was negative for p16. In addition, EBER was also negative. Morphologically the findings raised the possibility of non-keratinizing squamous cell carcinoma. RNA sequencing was undertaken to exclude the possibility of NUT carcinoma; interestingly, this revealed a novel ETV6-TNFRSF8 fusion transcript, which was independently confirmed by fluorescence in situ hybridization. The current case is illustrative because it broadens our understanding of the molecular pathogenesis of non-keratinizing squamous cell carcinoma and adds to the diversity of ETV6-rearranged malignancies.
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Affiliation(s)
- Justin Bubola
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Christina M MacMillan
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Ilan Weinreb
- Department of Pathology, University Health Network, Toronto, ON, Canada
| | - Ian Witterick
- Department of Otolaryngology Head and Neck Surgery, Department of Surgical Oncology, University Health Network, Toronto, ON, Canada
| | - David Swanson
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada
| | - Lei Zhang
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Cristina R Antonescu
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Brendan C Dickson
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, ON, Canada.
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
- Pathology & Laboratory Medicine, Mount Sinai Hospital, 600 University Ave, Suite 6.500.12.5, Toronto, ON, M5G 1X5, Canada.
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t(4;12)(q12;p13) ETV6-rearranged AML without eosinophilia does not involve PDGFRA: relevance for imatinib insensitivity. Blood Adv 2021; 6:818-827. [PMID: 34587239 PMCID: PMC8945303 DOI: 10.1182/bloodadvances.2021005280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 07/14/2021] [Indexed: 11/20/2022] Open
Abstract
Apparent ETV6-PDGFRA fusions identified by FISH analysis in t(4;12)(q12;p13) AML should be confirmed by sequencing. Sequence-confirmed ETV6-PDGFRA fusions have not been identified in patients with t(4;12)(q12;p13) AML without eosinophilia.
Acute myeloid leukemia (AML) with t(4;12)(q12;p13) translocation is rare and often associated with an aggressive clinical course and poor prognosis. Previous reports based on fluorescence in situ hybridization (FISH) analysis have suggested that ETV6::PDGFRA fusions are present in these patients, despite the absence of eosinophilia, which is typically found in other hematopoietic malignancies with PDGFRA-containing fusions. We first detected an ETV6-SCFD2 fusion by targeted RNA sequencing in a patient with t(4;12)(q12;p13) who had been diagnosed with an ETV6-PDGFRA fusion by FISH analysis but failed to respond to imatinib. We then retrospectively identified 4 additional patients with AML and t(4;12)(q12;p13) with apparent ETV6-PDGFRA fusions using chromosome and FISH analysis and applied targeted RNA sequencing to archival material. We again detected rearrangements between ETV6 and non-PDGFRA 4q12 genes, including SCFD2, CHIC2, and GSX2. None of the 3 patients who received imatinib based on the incorrect assumption of an ETV6-PDGFRA fusion responded. Our findings highlight the importance of using a sequencing-based assay to confirm the presence of targetable gene fusions, particularly in genomic regions, such as 4q12, with many clinically relevant genes that are too close to resolve by chromosome or FISH analysis. Finally, combining our data and review of the literature, we show that sequence-confirmed ETV6-PDGFRA fusions are typically found in eosinophilic disorders (3/3 cases), and patients with t(4;12)(q12;p13) without eosinophilia are found to have other 4q12 partners on sequencing (17/17 cases).
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