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Nath S, Bhattacharyya J, Chandra P, Saxena R, Sazawal S, Saikia KK. Clinicopathological Significance of Common Genetic Alterations in Patients With Acute Promyelocytic Leukemia. Hematol Oncol Stem Cell Ther 2022; 15:54-57. [PMID: 32755558 DOI: 10.1016/j.hemonc.2020.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 07/12/2020] [Indexed: 01/27/2023] Open
Abstract
OBJECTIVE/BACKGROUND Acute myeloid leukemia (AML) is one of the common forms of hematological malignancy and acute promyelocytic leukemia (APL) is a unique subtype of AML conferring favorable prognosis. We aimed to determine the prevalence and prognostic impact of Fms-like tyrosine kinase 3 (FLT3), nucleophosmin 1 (NPM1) mutation, epidermal growth factor receptor (EGFR), and flow marker's expression in patients with APL. METHODS In the present study, 165 de novo APL patients were molecularly characterized for promyelocytic leukemia (PML) breakpoint and additional genetic alterations. Reverse transcriptase polymerase chain reaction (PCR) and real-time PCR assays were used to detect genetic alterations. RESULTS PML/RARα was detected in 29/165 (17.5%) samples with breakpoint cluster region 1 (bcr1) in 17/29 (58.5%) and bcr3 in 12/29 (41.5%) samples. The prevalence of FLT3-ITD, NPM1, and EGFR were detected in 5/29 (17.5%), 11/29 (38%), and 5/29 (17.5%) patients, respectively. Patients expressing bcr-3 hybrid transcript had lower overall survival compared with bcr1 ( p = .254). White blood cell (WBC) count was significantly higher in bcr3 in comparison with bcr1 patients ( p = .002). Patients with positive EGFR expression ( p = .042) and higher WBC ( p = .002) were significantly associated with poor survival ( p < .05). CONCLUSIONS We documented the higher prevalence of bcr1 and confirmed that the association of FLT3-ITD significantly reduced the chances of survival in APL. The mortality rate of bcr3 was comparatively higher than that of bcr1. Higher WBC count and EGFR expression were significantly associated with poor survival.
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Affiliation(s)
- Sukanta Nath
- Department of Bioengineering and Technology, Gauhati University, Guwahati, Assam, India
| | - Jina Bhattacharyya
- Department of Clinical Haematology, Gauhati Medical College and Hospital, Guwahati, Assam, India
| | - Prem Chandra
- Medical Research Centre, Hamad Medical Corporation, Doha, Qatar
| | - Renu Saxena
- Department of Haematology, All India Institute of Medical Sciences, New Delhi, India
| | - Sudha Sazawal
- Department of Haematology, All India Institute of Medical Sciences, New Delhi, India
| | - Kandarpa Kumar Saikia
- Department of Bioengineering and Technology, Gauhati University, Guwahati, Assam, India
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Welch JS, Westervelt P, Ding L, Larson DE, Klco JM, Kulkarni S, Wallis J, Chen K, Payton JE, Fulton RS, Veizer J, Schmidt H, Vickery TL, Heath S, Watson MA, Tomasson MH, Link DC, Graubert TA, DiPersio JF, Mardis ER, Ley TJ, Wilson RK. Use of whole-genome sequencing to diagnose a cryptic fusion oncogene. JAMA 2011; 305:1577-84. [PMID: 21505136 PMCID: PMC3156695 DOI: 10.1001/jama.2011.497] [Citation(s) in RCA: 211] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
CONTEXT Whole-genome sequencing is becoming increasingly available for research purposes, but it has not yet been routinely used for clinical diagnosis. OBJECTIVE To determine whether whole-genome sequencing can identify cryptic, actionable mutations in a clinically relevant time frame. DESIGN, SETTING, AND PATIENT We were referred a difficult diagnostic case of acute promyelocytic leukemia with no pathogenic X-RARA fusion identified by routine metaphase cytogenetics or interphase fluorescence in situ hybridization (FISH). The case patient was enrolled in an institutional review board-approved protocol, with consent specifically tailored to the implications of whole-genome sequencing. The protocol uses a "movable firewall" that maintains patient anonymity within the entire research team but allows the research team to communicate medically relevant information to the treating physician. MAIN OUTCOME MEASURES Clinical relevance of whole-genome sequencing and time to communicate validated results to the treating physician. RESULTS Massively parallel paired-end sequencing allowed identification of a cytogenetically cryptic event: a 77-kilobase segment from chromosome 15 was inserted en bloc into the second intron of the RARA gene on chromosome 17, resulting in a classic bcr3 PML-RARA fusion gene. Reverse transcription polymerase chain reaction sequencing subsequently validated the expression of the fusion transcript. Novel FISH probes identified 2 additional cases of t(15;17)-negative acute promyelocytic leukemia that had cytogenetically invisible insertions. Whole-genome sequencing and validation were completed in 7 weeks and changed the treatment plan for the patient. CONCLUSION Whole-genome sequencing can identify cytogenetically invisible oncogenes in a clinically relevant time frame.
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MESH Headings
- Adult
- Chromosome Breakpoints
- Chromosomes, Human, Pair 15/genetics
- Chromosomes, Human, Pair 17/genetics
- Gene Fusion
- Genome, Human
- Humans
- Introns
- Leukemia, Promyelocytic, Acute/genetics
- Leukemia, Promyelocytic, Acute/therapy
- Male
- Nuclear Proteins/genetics
- Oncogene Proteins, Fusion/genetics
- Promyelocytic Leukemia Protein
- Receptors, Retinoic Acid/genetics
- Retinoic Acid Receptor alpha
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Analysis, DNA
- Transcription Factors/genetics
- Tumor Suppressor Proteins/genetics
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Affiliation(s)
- John S. Welch
- Department of Medicine, Washington University, St. Louis, MO
| | | | - Li Ding
- The Genome Institute, Washington University, St. Louis, MO
| | | | - Jeffery M. Klco
- Department of Pathology and Immunology, Washington University, St. Louis, MO
| | - Shashikant Kulkarni
- Department of Pathology and Immunology, Washington University, St. Louis, MO
- Department of Genetics, Washington University, St. Louis, MO
- Department of Pediatrics, Washington University, St. Louis, MO
| | - John Wallis
- The Genome Institute, Washington University, St. Louis, MO
| | - Ken Chen
- The Genome Institute, Washington University, St. Louis, MO
| | | | | | - Joelle Veizer
- The Genome Institute, Washington University, St. Louis, MO
| | | | | | - Sharon Heath
- Department of Medicine, Washington University, St. Louis, MO
| | - Mark A. Watson
- The Genome Institute, Washington University, St. Louis, MO
- Department of Pathology and Immunology, Washington University, St. Louis, MO
| | | | - Daniel C. Link
- Department of Medicine, Washington University, St. Louis, MO
| | | | | | - Elaine R. Mardis
- The Genome Institute, Washington University, St. Louis, MO
- Department of Genetics, Washington University, St. Louis, MO
| | - Timothy J. Ley
- Department of Medicine, Washington University, St. Louis, MO
- The Genome Institute, Washington University, St. Louis, MO
- Department of Genetics, Washington University, St. Louis, MO
| | - Richard K. Wilson
- The Genome Institute, Washington University, St. Louis, MO
- Department of Genetics, Washington University, St. Louis, MO
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Rara haploinsufficiency modestly influences the phenotype of acute promyelocytic leukemia in mice. Blood 2010; 117:2460-8. [PMID: 21190992 DOI: 10.1182/blood-2010-08-300087] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
RARA (retinoic acid receptor alpha) haploinsufficiency is an invariable consequence of t(15;17)(q22;q21) translocations in acute promyelocytic leukemia (APL). Retinoids and RARA activity have been implicated in hematopoietic self-renewal and neutrophil maturation. We and others therefore predicted that RARA haploinsufficiency would contribute to APL pathogenesis. To test this hypothesis, we crossed Rara(+/-) mice with mice expressing PML (promyelocytic leukemia)-RARA from the cathepsin G locus (mCG-PR). We found that Rara haploinsufficiency cooperated with PML-RARA, but only modestly influenced the preleukemic and leukemic phenotype. Bone marrow from mCG-PR(+/-) × Rara(+/-) mice had decreased numbers of mature myeloid cells, increased ex vivo myeloid cell proliferation, and increased competitive advantage after transplantation. Rara haploinsufficiency did not alter mCG-PR-dependent leukemic latency or penetrance, but did influence the distribution of leukemic cells; leukemia in mCG-PR(+/-) × Rara(+/-) mice presented more commonly with low to normal white blood cell counts and with myeloid infiltration of lymph nodes. APL cells from these mice were responsive to all-trans retinoic acid and had virtually no differences in expression profiling compared with tumors arising in mCG-PR(+/-) × Rara(+/+) mice. These data show that Rara haploinsufficiency (like Pml haploinsufficiency and RARA-PML) can cooperate with PML-RARA to influence the pathogenesis of APL in mice, but that PML-RARA is the t(15;17) disease-initiating mutation.
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Walz C, Grimwade D, Saussele S, Lengfelder E, Haferlach C, Schnittger S, Lafage-Pochitaloff M, Hochhaus A, Cross NCP, Reiter A. Atypical mRNA fusions in PML-RARA positive, RARA-PML negative acute promyelocytic leukemia. Genes Chromosomes Cancer 2010; 49:471-9. [PMID: 20155840 DOI: 10.1002/gcc.20757] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Reciprocal RARA-PML transcripts are not detected in approximately 25% of patients with PML-RARA positive acute promyelocytic leukemia (APL), but the reasons for this are poorly understood. We studied 21 PML-RARA positive/RARA-PML negative cases by bubble PCR and multiplex long template PCR to identify the genomic breakpoints. Additional RT-PCR analysis was performed based on the DNA findings. Three cases were found to have complex rearrangements involving a third locus: the first had a PML-CDC6-RARA forward DNA fusion and expressed a chimeric PML-CDC6-RARA mRNA in addition to a PML-RARA. The other two had HERC1-PML and NT_009714.17-PML genomic fusion sequences at their respective reciprocal breakpoints. Six patients were falsely classified as RARA-PML negative due to deletions on chromosome 15 and/or 17, or alternative splicing leading to atypical RARA-PML fusion transcripts, which were not identified by conventional RT-PCR assays. This study demonstrates that the frequency of RARA-PML expression has been underestimated and highlights remarkable complexity at chromosomal breakpoint regions in APL even in cases with an apparently simple balanced t(15;17)(q24;q12).
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Affiliation(s)
- Christoph Walz
- Pathologisches Institut, Universitätsmedizin Mannheim, Theodor-Kutzer-Ufer 1-3, Mannheim, Germany
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