RESUMO
The basis for acquired resistance to JAK inhibition in patients with JAK2-driven hematologic malignancies is not well understood. We report a patient with a myeloproliferative neoplasm (MPN) with a BCR activator of RhoGEF and GTPase (BCR)-JAK2 fusion with initial hematologic response to ruxolitinib who rapidly developed B-lymphoid blast transformation. We analyzed pre-ruxolitinib and blast transformation samples using genome sequencing, DNA mate-pair sequencing (MPseq), RNA sequencing (RNA-seq), and chromosomal microarray to characterize possible mechanisms of resistance. No resistance mutations in the BCR-JAK2 fusion gene or transcript were identified, and fusion transcript expression levels remained stable. However, at the time of blast transformation, MPseq detected a new IKZF1 copy-number loss, which is predicted to result in loss of normal IKZF1 protein translation. RNA-seq revealed significant upregulation of genes negatively regulated by IKZF1, including IL7R and CRLF2. Disease progression was also characterized by adaptation to an activated B-cell receptor (BCR)-like signaling phenotype, with marked upregulation of genes such as CD79A, CD79B, IGLL1, VPREB1, BLNK, ZAP70, RAG1, and RAG2. In summary, IKZF1 deletion and a switch from cytokine dependence to activated BCR-like signaling phenotype represent putative mechanisms of ruxolitinib resistance in this case, recapitulating preclinical data on resistance to JAK inhibition in CRLF2-rearranged Philadelphia chromosome-like acute lymphoblastic leukemia.
Assuntos
Ativação Linfocitária , Transtornos Mieloproliferativos , Humanos , Janus Quinase 2/genética , Nitrilas , Pirazóis/uso terapêutico , Pirimidinas , Receptores de Antígenos de Linfócitos BRESUMO
Overgrowth syndromes are rare genetic conditions which present as global or segmental hyperplasia and are sometimes associated with increased risk of malignancy. Trisomy of the terminal portion of 15q which includes the IGFR1 gene, produces a rare overgrowth phenotype that has been termed 15q overgrowth syndrome (15q OGS). Upregulation of IGF1R has long been implicated in oncogenesis of multiple cancer types, including acute leukemias, and has been shown to render cells more susceptible to other transforming events. To date, too few cases of 15q OGS have been reported to identify any cancer predisposition. We present a case of a 34-year-old female with intellectual disability, macrocephaly, and subtle dysmorphic features who was diagnosed with mixed phenotype acute leukemia (lymphoid and myeloid). Prior to initiation of therapy she was referred to medical genetics for further evaluation and was identified as having a chromosomal translocation resulting in a partial trisomy of chromosome 15q, consistent with 15q OGS. A review of the literature for cases of malignancy in individuals with increased copy number of 15q revealed only one other reported patient. Given the small number of reported individuals, we cannot rule out an increased risk of cancer associated with this chromosomal overgrowth syndrome. Although concerns have been raised regarding treatment feasibility in the setting of chromosomal disorders, the reported patient underwent successful treatment with allogeneic hematopoietic stem-cell transplant.
Assuntos
Cromossomos Humanos Par 15 , Transtornos do Crescimento/complicações , Transtornos do Crescimento/genética , Leucemia/diagnóstico , Leucemia/etiologia , Trissomia , Adulto , Fácies , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Transtornos do Crescimento/metabolismo , Humanos , Leucemia/metabolismo , Neoplasias/diagnóstico , Neoplasias/etiologia , Neoplasias/metabolismo , Linhagem , Receptor IGF Tipo 1/genética , Receptor IGF Tipo 1/metabolismo , Transdução de Sinais , SíndromeRESUMO
Undifferentiated malignancies (UMs) encompass a diverse set of aggressive tumors that pose not only a diagnostic challenge but also a challenge for clinical management. Most tumors in this category are currently treated empirically with nonspecific chemotherapeutic agents that yield extremely poor clinical response. Given that UMs are inherently genetically unstable neoplasms with the potential for immune dysregulation and increased neoantigen production, they are likely to be particularly amenable to immune checkpoint inhibitors, which target programmed cell death protein 1 (PD-1) or its ligands, PD-L1 and PD-L2, to promote T-cell antitumor activity. Aberrant expression of PD-L1 and, more recently, chromosomal 9p24.1/CD274(PD-L1)/PDCD1LG2(PD-L2) alterations can be used as biomarkers to predict responsiveness to checkpoint inhibitors. Here we evaluated 93 cases previously diagnosed as an "undifferentiated" malignancy and found that 56% (52/93) of UMs moderately to strongly express PD-L1 by immunohistochemistry (IHC). Concurrent CD274(PD-L1) and PDCD1LG2(PD-L2) fluorescence in situ hybridization (FISH) was performed on 24 of these cases and demonstrates a genetic gain at both loci in 62.5% of UMs. Genetic alterations at the CD274(PD-L1) and PDCD1LG2(PD-L2) loci were found to be completely concordant by FISH. Overall, we found that a significant proportion of UMs express PD-L1 and provide molecular support for using checkpoint inhibitors as a treatment approach for this class of tumors.
Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Antígeno B7-H1/imunologia , Biomarcadores Tumorais/imunologia , Diferenciação Celular , Imunoterapia/métodos , Neoplasias/imunologia , Proteína 2 Ligante de Morte Celular Programada 1/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/genética , Biomarcadores Tumorais/antagonistas & inibidores , Biomarcadores Tumorais/genética , Cromossomos Humanos Par 9 , Bases de Dados Factuais , Feminino , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Proteína 2 Ligante de Morte Celular Programada 1/antagonistas & inibidores , Proteína 2 Ligante de Morte Celular Programada 1/genética , Transdução de Sinais/efeitos dos fármacos , Adulto JovemRESUMO
Mediastinal teratomas are enigmatic; those in children and women are almost invariably benign but in men they may be benign or malignant. There are few data on the chromosome 12p status of mediastinal germ cell tumors (GCT), whereas increased 12p copy number is virtually uniform in malignant testicular GCTs. We therefore studied chromosome 12p copy number in 34 diverse mediastinal GCTs and correlated the results with morphology and follow-up to gain insight into possible pathogenesis. Four prepubertal (below 12 y) children (3 females and 1 male), 7 postpubertal females (14 to 52 y) and 6 postpubertal males (12 to 40 y old) had pure, previously untreated teratomas; 15 were mature and 2 had low-grade immaturity. All lacked 12p copy number increase and cytologic atypia, and most (14/17) showed organoid morphology. On follow-up of 16, 1 died of postoperative complications and the remaining 15 were disease free (1 to 119 mo, mean: 39 mo). Eight postpubertal males (19 to 44 y old) had pure teratomas in postchemotherapy resections; 5/8 showed 12p copy number increase. All 8 had distinct cytologic atypia, with organoid morphology in 3. On follow-up, 6 were disease free after surgical resection (1.5 to 94 mo, mean 38 mo); 1 died of disease at 14.5 months, and 1 was alive with metastases at 176 months. Two postpubertal patients, 1 male (29 y) and 1 female (31 y), had teratoma with secondary somatic-type malignancies, with positive 12p copy number increase in the former but not the latter. The man's tumor occurred after chemotherapy and was a nonorganoid teratoma with primitive neuroectodermal tumor and malignant glioma; the woman's was a previously untreated organoid teratoma with an undifferentiated carcinoma component. The man died of disease (16 mo) and the woman was alive with metastases (27 mo). Seven patients had resections for mixed GCTs (4) or pure nonteratomatous tumors, all after chemotherapy; 5/7 had positive 12p copy number increase. The teratoma component of the 2 cases having one showed distinct cytologic atypia and lacked organoid morphology. On follow-up, 1 died of disease (5 mo), 2 were alive with disease (1, 1.5 mo), 3 were disease free (1 to 43 mo; mean: 18 mo), and 1 was alive with unknown status (31 mo). Our results support that mediastinal teratomas likely develop from 2 separate pathways. Those in children, women and some men arise as pure neoplasms from a nontransformed precursor cell and, therefore, lack 12p copy number increase, show no cytologic atypia, often have organoid morphology and are benign. Common 12p copy number increase, uniform atypia, infrequent organoid structures and malignant behavior support that pure teratomas after chemotherapy in postpubertal males derive from a malignantly transformed precursor cell. Interestingly, we identified organoid pancreatic differentiation only in the benign group and neuroglia more commonly in the malignant teratomas.
Assuntos
Biomarcadores Tumorais/genética , Cromossomos Humanos Par 12/genética , Dosagem de Genes , Neoplasias do Mediastino/genética , Teratoma/genética , Adolescente , Adulto , Fatores Etários , Biópsia , Diferenciação Celular , Criança , Feminino , Predisposição Genética para Doença , Humanos , Hibridização in Situ Fluorescente , Masculino , Neoplasias do Mediastino/mortalidade , Neoplasias do Mediastino/patologia , Neoplasias do Mediastino/terapia , Pessoa de Meia-Idade , Fenótipo , Fatores de Risco , Fatores Sexuais , Teratoma/mortalidade , Teratoma/patologia , Teratoma/terapia , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
Chorionic villus sampling (CVS), routinely used for prenatal diagnosis of cytogenetic disorders, also possesses great potential for the study of placentation. To better understand villus biology, human placentation, and how these relate to pregnancy outcomes, we examined the morphology and transcriptomes of villi obtained via CVS from 10 to 14 weeks of pregnancy and correlated these with pregnancy attributes and clinical outcomes. First, we established a morphological scoring system based on three main villus features: branching, budding and vascularization. We then tested whether morphology scores were predictive of pregnancy attributes and clinical outcomes. Finally, we used RNA sequencing to assess the transcriptional basis of villus morphology and tested the hypothesis that gene expression may predict pregnancy outcomes. We demonstrate that villus morphology varies tremendously between patients, irrespective of gestational age, and that transcriptional differences are highly predictive of villus morphology. We show that pre-eclampsia markers are associated with villi with low morphology scores. Additionally, we identify SVEP1 as a possible biomarker for defining gestational age. Overall, chorionic villi in the first trimester remain one of the few means to correlate placental function with pregnancy outcome and these samples are a valuable and increasingly rare resource.
Assuntos
Vilosidades Coriônicas/metabolismo , Vilosidades Coriônicas/patologia , Placenta/metabolismo , Placentação/genética , Primeiro Trimestre da Gravidez/genética , Adulto , Biomarcadores/metabolismo , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Vilosidades Coriônicas/irrigação sanguínea , Vilosidades Coriônicas/crescimento & desenvolvimento , Amostra da Vilosidade Coriônica , Análise Citogenética , Feminino , Perfilação da Expressão Gênica , Idade Gestacional , Humanos , Masculino , Tamanho do Órgão , Placenta/patologia , Gravidez , Resultado da Gravidez/genética , Diagnóstico Pré-Natal , Análise de Sequência de RNARESUMO
FLT3 fusions are associated with myeloid and lymphoid neoplasms with eosinophilia. We describe a patient presenting with clinicopathologic features of both chronic eosinophilic leukemia, not otherwise specified (CEL, NOS) and systemic mastocytosis (SM). The bone marrow demonstrated a myeloproliferative neoplasm with eosinophilia and aggregates of atypical mast cells. Cytogenetic analysis revealed a t(13;14)(q12;q32), which was subsequently molecularly characterized as a novel TRIP11-FLT3 rearrangement. A KIT D816V mutation was also identified. The patient rapidly transformed to T-lymphoblastic leukemia/lymphoma and expired shortly after diagnosis. This is the fifth FLT3 fusion gene described in the literature; the presence of both myeloid and lymphoid neoplasms implicates involvement of an early hematopoietic progenitor by rearranged FLT3. We suggest that leukemias and lymphomas with FLT3 fusion genes exhibit similar clinicopathologic features to, and should be included in, the WHO category of "Myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB, or FGFR1, or with PCM1-JAK2."
Assuntos
Eosinofilia/complicações , Linfoma/complicações , Linfoma/genética , Transtornos Mieloproliferativos/complicações , Transtornos Mieloproliferativos/genética , Proteínas de Fusão Oncogênica/genética , Tirosina Quinase 3 Semelhante a fms/genética , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The presence of a monosomal karyotype (MK+) and/or a complex karyotype (CK+) identifies subcategories of AML with poor prognosis. The prognostic significance of the most common monosomies (monosomy 5, monosomy 7, and monosomy 17) within MK+/CK+AML is not well defined. We analyzed data from 1,592 AML patients age 17-93 years enrolled on ECOG-ACRIN therapeutic trials. The majority of MK+ patients (182/195; 93%) were MK+/CK+ with 87% (158/182) having ≥5 clonal abnormalities (CK≥5). MK+ patients with karyotype complexity ≤4 had a median overall survival (OS) of 0.4y compared to 1.0y for MK- with complexity ≤4 (p<0.001), whereas no OS difference was seen in MK+vs. MK- patients with CK≥5 (p=0.82). Monosomy 5 (93%; 50/54) typically occurred within a highly complex karyotype and had no impact on OS (0.4y; p=0.95). Monosomy 7 demonstrated no impact on OS in patients with CK≥5 (p=0.39) or CK≤4 (p=0.44). Monosomy 17 appeared in 43% (68/158) of CK≥5 patients and demonstrated statistically significant worse OS (0.4y) compared to CK≥5 patients without monosomy 17 (0.5y; p=0.012). Our data suggest that the prognostic impact of MK+is limited to those with less complex karyotypes and that monosomy 17 may independently predict for worse survival in patients with AML.
Assuntos
Cromossomos Humanos Par 17/genética , Leucemia Mieloide Aguda/genética , Monossomia/genética , Prognóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Deleção Cromossômica , Cromossomos Humanos Par 5 , Cromossomos Humanos Par 7 , Humanos , Cariotipagem , Leucemia Mieloide Aguda/mortalidade , Pessoa de Meia-Idade , Taxa de Sobrevida , Adulto JovemRESUMO
DISCLAIMER: These American College of Medical Genetics and Genomics standards and guidelines are developed primarily as an educational resource for clinical laboratory geneticists to help them provide quality clinical laboratory genetic services. Adherence to these standards and guidelines is voluntary and does not necessarily ensure a successful medical outcome. These standards and guidelines should not be considered inclusive of all proper procedures and tests or exclusive of other procedures and tests that are reasonably directed to obtaining the same results. In determining the propriety of any specific procedure or test, the clinical laboratory geneticist should apply his or her own professional judgment to the specific circumstances presented by the individual patient or specimen. Clinical laboratory geneticists are encouraged to document in the patient's record the rationale for the use of a particular procedure or test, whether or not it is in conformance with these standards and guidelines. They also are advised to take notice of the date any particular guideline was adopted, and to consider other relevant medical and scientific information that becomes available after that date. It also would be prudent to consider whether intellectual property interests may restrict the performance of certain tests and other procedures.Cytogenetic analyses of hematological neoplasms are performed to detect and characterize clonal chromosomal abnormalities that have important diagnostic, prognostic, and therapeutic implications. At the time of diagnosis, cytogenetic abnormalities assist in the diagnosis of such disorders and can provide important prognostic information. At the time of relapse, cytogenetic analysis can be used to confirm recurrence of the original neoplasm, detect clonal disease evolution, or uncover a new unrelated neoplastic process. This section deals specifically with the standards and guidelines applicable to chromosome studies of neoplastic blood and bone marrow-acquired chromosomal abnormalities. This updated Section E6.1-6.4 has been incorporated into and supersedes the previous Section E6 in Section E: Clinical Cytogenetics of the 2009 Edition (Revised 01/2010), American College of Medical Genetics and Genomics Standards and Guidelines for Clinical Genetics Laboratories.Genet Med 18 6, 635-642.
Assuntos
Aberrações Cromossômicas , Testes Genéticos/normas , Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/genética , Medula Óssea/patologia , Citodiagnóstico/normas , Análise Citogenética/normas , Genômica/normas , Guias como Assunto , Neoplasias Hematológicas/epidemiologia , Humanos , Laboratórios/normas , Estados UnidosRESUMO
OBJECTIVES: B-lymphoblastic leukemia (B-ALL) with intrachromosomal amplification of chromosome 21 (iAMP21) is a relatively uncommon manifestation of acute leukemia and limited predominantly to the pediatric population. Case-specific information regarding flow cytometric, morphologic, and laboratory findings of this subtype of leukemia is currently lacking. METHODS: We searched the databases of three large institutions for lymphoblastic leukemia with iAMP21 from 2005 through 2012 and analyzed the clinicopathologic features. RESULTS: We identified 17 cases with five or more RUNX1 signals on interphase nuclei, 14 of which were consistent with the Children's Oncology Group (COG) definition for iAMP21namely, the presence of three or more RUNX1 signals on one marker chromosome. These cases showed a statistically significant lower peripheral WBC count and older age at diagnosis compared with all pediatric cases of B-ALL. We also identified three cases with increased RUNX1 signals scattered on multiple marker chromosomes that did not meet the COG definition of iAMP21 but showed similar 21q instability and older age at presentation. CONCLUSIONS: Our findings not only demonstrate that B-ALL with iAMP21 is truly a distinct clinicopathologic entity but also suggest that a subset of cases of B-ALL with iAMP21 can show variable cytogenetic features.
Assuntos
Cromossomos Humanos Par 21/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Adolescente , Criança , Pré-Escolar , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Análise Citogenética , Feminino , Citometria de Fluxo , Amplificação de Genes , Humanos , Masculino , Adulto JovemRESUMO
OBJECTIVE: We sought to determine the positive predictive value (PPV) of noninvasive prenatal screening (NIPS) for various aneuploidies based on cases referred for follow-up cytogenetic testing. Secondarily, we wanted to determine the false-negative (FN) rate for those cases with a negative NIPS result. STUDY DESIGN: We compared the cytogenetic findings (primarily from chromosome analysis) from 216 cases referred to our laboratories with either a positive or negative NIPS result, and classified NIPS results as true positive, false positive, true negative, or FN. Diagnostic cytogenetic testing was performed on the following tissue types: amniotic fluid (n = 137), chorionic villi (n = 69), neonatal blood (n = 6), and products of conception (n = 4). RESULTS: The PPV for NIPS were as follows: 93% for trisomy (T)21 (n = 99; 95% confidence interval [CI], 86-97.1%), 58% for T18 (n = 24; 95% CI, 36.6-77.9%), 45% for T13 (n = 11; 95% CI, 16.7-76.6%), 23% for monosomy X (n = 26; 95% CI, 9-43.6%), and 67% for XXY (n = 6; 95% CI, 22.3-95.7%). Of the 26 cases referred for follow-up cytogenetics after a negative NIPS result, 1 (4%) was FN (T13). Two cases of triploidy, a very serious condition but one not claimed to be detectable by the test providers, were among those classified as true negatives. CONCLUSION: T21, which has the highest prevalence of all aneuploidies, demonstrated a high true-positive rate, resulting in a high PPV. However, the other aneuploidies, with their lower prevalence, displayed relatively high false-positive rates and, therefore, lower PPV. Patients and physicians must fully understand the limitations of this screening test and the need in many cases to follow up with appropriate diagnostic testing to obtain an accurate diagnosis.
Assuntos
Aberrações Cromossômicas , Transtornos Cromossômicos/diagnóstico , DNA/sangue , Adulto , Amniocentese , Aneuploidia , Amostra da Vilosidade Coriônica , Transtornos Cromossômicos/genética , Cromossomos Humanos Par 13/genética , Cromossomos Humanos Par 18/genética , Estudos de Coortes , Análise Citogenética , Síndrome de Down/diagnóstico , Síndrome de Down/genética , Reações Falso-Negativas , Feminino , Humanos , Síndrome de Klinefelter/diagnóstico , Síndrome de Klinefelter/genética , Valor Preditivo dos Testes , Gravidez , Diagnóstico Pré-Natal , Estudos Retrospectivos , Trissomia/diagnóstico , Trissomia/genética , Síndrome da Trissomia do Cromossomo 13 , Síndrome da Trissomía do Cromossomo 18 , Síndrome de Turner/diagnóstico , Síndrome de Turner/genéticaRESUMO
Acute myeloid leukemia and myelodysplastic syndrome with inv(3)(q21q26.2)/t(3;3)(q21;q26.2) have a poor prognosis. Indeed, the inv(3)(q21q26.2)/t(3;3)(q21;q26.2) has been recognized as a poor risk karyotype in the revised International Prognostic Scoring System. However, inv(3)(q21q26.2)/t(3;3)(q21;q26.2) is not among the cytogenetic abnormalities pathognomonic for diagnosis of acute myeloid leukemia irrespective of blast percentage in the 2008 WHO classification. This multicenter study evaluated the clinico-pathological features of acute myeloid leukemia/myelodysplastic syndrome patients with inv(3)(q21q26.2)/t(3;3)(q21;q26.2) and applied the revised International Prognostic Scoring System to myelodysplastic syndrome patients with inv(3)(q21q26.2)/t(3;3)(q21;q26.2). A total of 103 inv(3)(q21q26.2)/t(3;3)(q21;q26.2) patients were reviewed and had a median bone marrow blast count of 4% in myelodysplastic syndrome (n=40) and 52% in acute myeloid leukemia (n=63) (P<0.001). Ninety-one percent of patients showed characteristic dysmegakaryopoiesis. There was no difference in overall survival between acute myeloid leukemia and myelodysplastic syndrome patients with inv(3)(q21q26.2)/t(3;3)(q21;q26.2) (12.9 vs. 7.9 months; P=0.16). Eighty-three percent of patients died (median follow up 7.9 months). Complex karyotype, monosomal karyotype and dysgranulopoiesis (but not blast percentage) were independent poor prognostic factors in the entire cohort on multivariable analysis. The revised International Prognostic Scoring System better reflected overall survival of inv(3)(q21q26.2)/t(3;3)(q21;q26.2) than the International Prognostic Scoring System but did not fully reflect the generally dismal prognosis. Our data support consideration of myelodysplastic syndrome with inv(3)(q21q26.2)/t(3;3)(q21;q26.2) as an acute myeloid leukemia with recurrent genetic abnormalities, irrespective of blast percentage.
Assuntos
Cariótipo Anormal , Medula Óssea/patologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Inversão Cromossômica , Cromossomos Humanos Par 3 , Feminino , Seguimentos , Transplante de Células-Tronco Hematopoéticas , Humanos , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/terapia , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/mortalidade , Síndromes Mielodisplásicas/terapia , Avaliação de Resultados da Assistência ao Paciente , Prognóstico , Translocação Genética , Adulto JovemRESUMO
OBJECTIVES: To assess the frequency of systemic mastocytosis (SM) in a large series of acute myeloid leukemia (AML) with t(8;21)(q22;q22). METHODS: We retrospectively characterized 40 bone marrow aspirate smears and biopsy specimens from patients with AML with t(8;21) for the presence of SM. Cases were assessed for mast cell morphology and immunohistochemistry, as well as KIT exon 8 and 17 mutational assessment by reverse transcription polymerase chain reaction. RESULTS: Four patients met criteria for SM, 1 met criteria for myelomastocytic leukemia, and 8 demonstrated the benign finding of mast cell hyperplasia. CONCLUSIONS: We recommend examining all cases of AML with t(8;21) for the presence of SM via morphology, immunophenotyping, and KIT mutational analysis studies.
Assuntos
Cromossomos Humanos Par 21 , Cromossomos Humanos Par 8 , Leucemia Mieloide Aguda/patologia , Mastocitose Sistêmica/patologia , Translocação Genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Células da Medula Óssea/patologia , Criança , Pré-Escolar , Análise Mutacional de DNA , Feminino , Humanos , Hiperplasia , Leucemia Mieloide Aguda/complicações , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Masculino , Mastócitos/patologia , Mastocitose Sistêmica/complicações , Mastocitose Sistêmica/genética , Mastocitose Sistêmica/metabolismo , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-kit/genética , Estudos Retrospectivos , Adulto JovemRESUMO
OBJECTIVES: To assess a large series of patients with acute myeloid leukemia (AML) with t(8;21) for both IGH@ and IGK@ B-cell gene rearrangements and for expression of PAX5, OCT2, and Bob.1 by immunohistochemistry and expression of CD19, CD79a, CD20, and CD22 by flow cytometry immunophenotyping. METHODS: A total of 48 cases of AML with t(8;21)(q22;q22) were evaluated by immunohistochemistry and/or heavy chain and light chain immunoglobulin rearrangement studies where paraffin-embedded and/or fresh frozen material was available for study; previously performed flow cytometry studies were also reviewed in available cases. RESULTS: Our study yielded 1 of 19 cases of AML with t(8;21) with an IGH@ gene rearrangement; blasts were associated with weak PAX5 expression. In addition, expression of antigens CD79a by flow cytometry and OCT2 by immunohistochemistry were highly associated with PAX5 expression, and CD19 was expressed in most cases assessed. CONCLUSIONS: Although B-cell antigen and B-cell transcription factor expression is seen in the majority of AMLs with t(8;21)(q22;q22) and correlates with PAX5 expression, immunoglobulin gene rearrangements are an uncommon event in this group of leukemias.
Assuntos
Rearranjo Gênico do Linfócito B , Genes de Imunoglobulinas/genética , Leucemia Mieloide Aguda/metabolismo , Fator 2 de Transcrição de Octâmero/metabolismo , Fator de Transcrição PAX5/genética , Fator de Transcrição PAX5/metabolismo , Transativadores/metabolismo , Antígenos CD19/genética , Antígenos CD19/metabolismo , Antígenos CD20/genética , Antígenos CD20/metabolismo , Linfócitos B/metabolismo , Antígenos CD79/genética , Antígenos CD79/metabolismo , Feminino , Humanos , Imunofenotipagem , Leucemia Mieloide Aguda/genética , Masculino , Fator 2 de Transcrição de Octâmero/genética , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Transativadores/genéticaRESUMO
In order to identify novel somatic mutations associated with classic BCR/ABL1-negative myeloproliferative neoplasms, we performed high-coverage genome sequencing of DNA from peripheral blood granulocytes and cultured skin fibroblasts from a patient with MPL W515K-positive primary myelofibrosis. The primary myelofibrosis genome had a low somatic mutation rate, consistent with that observed in similar hematopoietic tumor genomes. Interfacing of whole-genome DNA sequence data with RNA expression data identified three somatic mutations of potential functional significance: i) a nonsense mutation in CARD6, implicated in modulation of NF-kappaB activation; ii) a 19-base pair deletion involving a potential regulatory region in the 5'-untranslated region of BRD2, implicated in transcriptional regulation and cell cycle control; and iii) a non-synonymous point mutation in KIAA0355, an uncharacterized protein. Additional mutations in three genes (CAP2, SOX30, and MFRP) were also evident, albeit with no support for expression at the RNA level. Re-sequencing of these six genes in 178 patients with polycythemia vera, essential thrombocythemia, and myelofibrosis did not identify recurrent somatic mutations in these genes. Finally, we describe methods for reducing false-positive variant calls in the analysis of hematologic malignancies with a low somatic mutation rate. This trial is registered with ClinicalTrials.gov (NCT01108159).
Assuntos
Estudos de Associação Genética/métodos , Variação Genética/genética , Estudo de Associação Genômica Ampla/métodos , Mutação/genética , Mielofibrose Primária/diagnóstico , Mielofibrose Primária/genética , Células Cultivadas , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
In patients with myelodysplastic syndromes (MDS), chromosome anomalies are detected by conventional cytogenetic studies (CCS) and/or interphase fluorescence in situ hybridization (FISH) of bone marrow (BM) samples and provide prognostic and diagnostic information, which can direct therapy. Whether peripheral blood (PB) can be substituted for bone marrow in these cases and can provide the same information remains unknown. Concurrent BM and PB specimens collected from 100 patients with recently diagnosed MDS were studied using both CCS and FISH. While 68% of BM samples showed an abnormal karyotype by CCS, only 31% of PB samples were abnormal by CCS. In 12% of patients, FISH and CCS were discordant due to the inability of the FISH panel to detect all possible abnormalities. However, only one case (1%) had a cryptic abnormality detected by FISH. BM and PB FISH were discordant in 3% of cases, most likely due to the smaller clone size in PB vs. BM. While PB should not be substituted for BM at diagnosis, it is a viable alternative for monitoring patients using the appropriate FISH probe(s).
Assuntos
Análise Citogenética/métodos , Oncologia/métodos , Síndromes Mielodisplásicas/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha , Exame de Medula Óssea/métodos , Criança , Citogenética/métodos , Feminino , Testes Hematológicos/métodos , Humanos , Cariotipagem/métodos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Síndromes Mielodisplásicas/sangue , Síndromes Mielodisplásicas/patologia , Prognóstico , Adulto JovemRESUMO
Recent evidence suggests that trastuzumab, a monoclonal antibody which targets HER2, in combination with chemotherapy is a therapeutic option in patients with HER2-positive gastric or gastroesophageal junction cancer. Widely accepted guidelines for HER2 testing in gastric and gastroesophageal junction cancer have not been established. The purpose of this study was to analyze the incidence and patterns of HER2 expression in gastric and gastroesophageal junction cancer using a tissue microarray approach, which closely simulates small biopsies routinely tested for HER2. One hundred sixty-nine patients, including 99 primary gastric adenocarcinomas and 70 primary gastroesophageal junction carcinomas were analyzed for HER2 overexpression by immunohistochemistry and HER2 gene amplification by fluorescence in situ hybridization using scoring schemes proposed by both American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) and the results of the recently published Trastuzumab for Gastric Cancer (ToGA) trial. In our analysis, 19 adenocarcinomas were HER2 positive, defined as either a HER2/CEP17 ratio >2.2 and/or a 3+ HER2 immunohistochemistry score with either the ASCO/CAP or ToGA scoring schemes. Of the 19 HER2-positive adenocarcinomas, 8 (42%) exhibited a characteristic strongly intense basolateral membranous staining pattern which would be interpreted as negative (1+) using the accepted ASCO/CAP scoring scheme for HER2 assessment in breast carcinoma, but were correctly labeled as 3+ positive using the proposed ToGA scoring scheme. Of the 19 HER2-positive adenocarcinomas, 8 (42%) demonstrated heterogeneous HER2 protein expression by immunohistochemistry. Twelve of 99 (12%) gastric carcinomas were positive for HER2. Of these, HER2 was more often identified in intestinal-type adenocarcinomas (10 of 52, 19%) compared with diffuse (2 of 34, 6%) adenocarcinoma. Seven of 70 (10%) gastroesophageal junction carcinomas were positive for HER2 of which all were intestinal type (7 of 58, 12%). HER2 status or primary tumor site did not correlate with patient survival. Gastric and gastroesophageal junction adenocarcinomas typically display a characteristic basolateral membranous pattern of HER2 expression which is often heterogeneous rendering routine evaluation of HER2 status on small tissue samples challenging.
Assuntos
Adenocarcinoma , Neoplasias Esofágicas , Regulação Neoplásica da Expressão Gênica , Receptor ErbB-2/biossíntese , Neoplasias Gástricas , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Feminino , Seguimentos , Humanos , Imuno-Histoquímica/métodos , Imuno-Histoquímica/normas , Hibridização in Situ Fluorescente/métodos , Hibridização in Situ Fluorescente/normas , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Estados Unidos/epidemiologiaRESUMO
Clonal chromosomal abnormalities are often found in the tumor cells of patients with malignancies. These abnormalities can cause downregulation of human leukocyte antigen (HLA) and instability of short tandem repeat (STR) DNA sequences, confounding HLA typing and/or engraftment analysis in hematopoietic stem cell transplants (HSCT). We describe here the abnormalities observed during testing of 600 HSCT patients. HLA molecular typing was performed by reference strand conformational analyses and/or sequence-based typing. STR testing was performed with 10 to 16 STR primer sets, following 1 to 4 informative loci in each patient. Eight patients exhibited either loss of heterozygosity (4 STR, 3 HLA) or STR length mutation (n = 1), and 5 of the 8 exhibited correlative cytogenetic abnormalities. Diagnoses were acute myelogenous leukemia (AML; n = 7) or myelofibrosis (MFIB: n = 1), yielding an 11% incidence of these chromosomal abnormalities among the subset of 72 AML/MFIB HSCT patients. These results highlight some of the problems encountered and the possibility for interpretive errors that can arise when analyzing molecular typing and engraftment data, particularly among AML/MFIB patients.
Assuntos
Antígenos HLA/genética , Transplante de Células-Tronco Hematopoéticas , Leucemia Mieloide Aguda/genética , Repetições de Microssatélites/genética , Mielofibrose Primária/genética , Adulto , Aberrações Cromossômicas/estatística & dados numéricos , Análise Mutacional de DNA/métodos , Feminino , Teste de Histocompatibilidade/métodos , Humanos , Incidência , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/epidemiologia , Leucemia Mieloide Aguda/imunologia , Masculino , Mutação/genética , Mielofibrose Primária/diagnóstico , Mielofibrose Primária/epidemiologia , Mielofibrose Primária/imunologia , Tolerância ao Transplante/genéticaRESUMO
Translocations are key oncogenic events, and many rearrangements are characteristic for a specific malignancy. We present here a case of phenotypic precursor-B acute lymphoblastic leukemia (ALL), subsequently found to have both MYC and MLL translocations. Owing to the potential prognostic impact of these translocations, a novel treatment strategy was applied which merged precursor-B ALL, Burkitt-ALL, and "MLL-adapted" rationales. With the advent of expanding diagnostic panels and molecular therapeutic options, use of such adapted therapies for individualized treatment will undoubtedly continue to increase as we move toward pharmacogenomic-based approaches.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Proteína de Leucina Linfoide-Mieloide/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Proteínas Proto-Oncogênicas c-myc/genética , Translocação Genética , Pré-Escolar , Ciclofosfamida/administração & dosagem , Citarabina/administração & dosagem , Doxorrubicina/administração & dosagem , Citometria de Fluxo , Histona-Lisina N-Metiltransferase , Humanos , Masculino , Metotrexato/administração & dosagem , Prednisona/administração & dosagem , Vincristina/administração & dosagemRESUMO
Chordomas are malignant neoplasms that typically arise in the axial spine and primarily affect adults. When chordomas arise in pediatric patients they are more likely to display unusual histological features and aggressive behavior. We noted the absence of SMARCB1/INI1 expression by immunohistochemistry in an index case of poorly differentiated chordoma of the sacrum, leading us to further examine SMARCB1/INI1 expression as well as that of brachyury, a highly specific marker of notochordal differentiation, in 3 additional poorly differentiated chordomas of the clivus, 10 typical chordomas, and 8 atypical teratoid/rhabdoid tumors (AT/RTs). All 4 poorly differentiated chordomas and all AT/RTs lacked nuclear expression of SMARCB1/INI1, while the 10 typical chordomas maintained strong nuclear SMARCB1/INI1 immunoreactivity. All 10 typical and 4 poorly differentiated chordomas expressed brachyury; all 8 AT/RTs were brachyury immunonegative. Cytogenetic evaluation utilizing FISH probes near the SMARCB1/INI1 locus on chromosome 22q was also performed in all of the poorly differentiated chordomas in this series. Three of the four poorly differentiated chordomas had evidence for deletion of this region by FISH. Analysis of the SMARCB1/INI1 gene sequence was performed using formalin-fixed paraffin-embedded tissue in all cases and no point mutations were observed. In summary, all poorly differentiated chordomas in this series showed the absence of SMARCB1/INI1 expression, and were reliably distinguished from AT/RTs, clinically by their characteristic primary sites of origin and pathologically by strong nuclear brachyury expression. Our findings reveal a likely role for SMARCB1/INI1 in a subset of chordomas with aggressive features.
Assuntos
Cordoma/genética , Cordoma/patologia , Proteínas Cromossômicas não Histona/antagonistas & inibidores , Proteínas Cromossômicas não Histona/biossíntese , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/biossíntese , Deleção de Genes , Mutação/genética , Neoplasias da Coluna Vertebral/genética , Neoplasias da Coluna Vertebral/patologia , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/biossíntese , Diferenciação Celular/genética , Criança , Pré-Escolar , Cordoma/metabolismo , Proteínas Cromossômicas não Histona/genética , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Lactente , Masculino , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Proteína SMARCB1 , Neoplasias da Coluna Vertebral/metabolismo , Fatores de Transcrição/genéticaRESUMO
D-cyclin proteins play a central role in cell-cycle regulation and are involved in the pathogenesis of lymphomas. In mantle-cell lymphoma, the t(11;14) translocation leads to overexpression of cyclin-D1, in addition to which cyclin-D1-negative mantle-cell lymphoma that overexpress cyclin-D2 or D3 have also been described. Although cyclin-D2 and D3 have been implicated in the prognosis of specific lymphoma subtypes, a thorough characterization of D-cyclin protein expression in human hematolymphoid neoplasia has not been reported. To evaluate the tissue expression patterns of D-cyclins, particularly D2 and D3, in normal and neoplastic hematolymphoid tissues, we optimized the commercially available antibodies for D-cyclins for use on paraffin-embedded tissue and stained tissue microarrays of over 700 patient samples. Our results show that cyclin-D2 and D3 proteins are expressed in many more lymphoma subtypes than cyclin-D1. Cyclin-D1, D2 and D3 were expressed in 100, 22 and 6% of mantle-cell lymphomas and 2, 49 and 20% of diffuse large B-cell lymphomas. Fluorescence in situ hybridization studies confirmed the presence of the CCND1/IGH translocation in the majority of mantle-cell lymphoma, but not in diffuse large B-cell lymphoma that expressed cyclin-D1 protein. In addition, a subset of follicular, marginal zone, lymphoplasmacytic, lymphoblastic, classical Hodgkin, mature T-cell and natural killer cell lymphomas and acute myeloid leukemias also expressed cyclin-D2 and D3. These data support the hypothesis that dysregulation of cell-cycle control by D-cyclins contribute to the pathogenesis of hematolymphoid neoplasia, and suggest a potential role for these proteins in the prognostic and therapeutic aspects of these diseases. For diagnostic purposes, however, the expression of D-cyclin proteins should be interpreted with caution in the subclassification of lymphoma types.