Exploring redox vulnerabilities in JAK2V617F-positive cellular models

ABSTRACT Background: In Philadelphia chromosome-negative myeloproliferative neoplasm (MPN) models, reactive oxygen species (ROS) are elevated and have been implicated in genomic instability, JAK2/STAT signaling amplification, and disease progression. Although the potential effects of ROS on the MPN phenotype, the effects of ruxolitinib treatment on ROS regulation have been poorly explored. Herein, we have reported the impact of ruxolitinib on redox signaling transcriptional network, and the effects of diphenyleneiodonium (DPI), a pan NOX inhibitor, in JAK2V617F-driven cellular models. Method: Redox signaling-related genes were investigated in SET2 cells upon ruxolitinib treatment by RNA-seq (GEO accession GSE69827). SET2 and HEL cells, which represent JAK2V617F-positive MPN cellular models with distinct sensitivity to apoptosis induced by ruxolitinib, were used. Cell viability was evaluated by MTT, apoptosis by annexin V/PI and flow cytometry, and cell signaling by quantitative PCR and Western blot. Main results: Ruxolitinib impacted on a network composed of redox signaling-related genes, and DUOX1 and DUOX2 were identified as potential modulators of ruxolitinib response. In SET2 and HEL cells, DPI reduced cell viability and, at low doses, it significantly potentiated ruxolitinib-induced apoptosis. In the molecular scenario, DPI inhibited STAT3, STAT5 and S6 ribosomal protein phosphorylation and induced PARP1 cleavage in JAK2V617F-positive cells. DPI combined with ruxolitinib increased PARP1 cleavage in SET2 cells and potentiated ruxolitinib-reduced STAT3, STAT5 and S6 ribosomal protein in HEL cells. Conclusion: Our study reveals a potential adaptation mechanism for resistance against ruxolitinib by transcriptionally reprogramming redox signaling in JAK2V617F cells and exposes redox vulnerabilities with therapeutic value in MPN cellular models.

Panmielosis aguda con mielofibrosis / Acute panmyelosis with myelofibrosis

La panmielosis aguda con mielofibrosis (PMAF) es un raro desorden hematológico, definido como un subtipo de leucemia aguda. Se reporta un paciente masculino de 31 años de edad con historia de decaimiento marcado, fiebre vespertina y gingivorragia. El examen físico muestra palidez cutáneo mucosas, esplenomegalia ligera y en exámenes complementarios pancitopenia con 5 por ciento de blastos. En el medulograma no se obtuvo material y la impronta sugiere leucemia mieloide aguda no promielocítica. El estudio de inmunofenotipo por citometría de flujo confirma incremento de mieloblastos positivo para (CD34, CD13, CD17, CD117, CD38) y disminuidos en (CD11c y HLA-DR), con una mielofibrosis marcada en biopsia de medula ósea sin la presencia de blastos. Recibe tratamiento de inducción con esquema 3 + 7 (Citosar + Rubidomicina) después del cual el paciente se encuentra en remisión hematológica con persistencia de la fibrosis medular. Posteriormente inicia tratamiento con lenalidomida, Bifosfonatos (Ácido Zoledronico) y se encuentra en remisión hematológica 11 meses después del diagnóstico, hasta marzo 2020. Se realizan estudios de histocompatibilidad (HLA) para trasplante alogénico(AU)

Acute panmyelosis with myelofibrosis (PMAF) is a rare hematologic disorder, defined as a subtype of acute leukemia. A 31-year-old male patient with a history of marked decay, evening fever, and gingivorrhagia is reported. The physical examination showed mucous skin paleness, slight splenomegaly and the complementary examinations showed pancytopenia with 5 percent blasts. In the medullogram no material was obtained and the imprint suggests non-promyelocytic acute myeloid leukemia. Immunophenotype study by flow cytometry confirmed an increase in myeloblasts positive for (CD34, CD13, CD17, CD117, CD38) and decreased in (CD11c and HLA-DR), with marked myelofibrosis in bone marrow biopsy without the presence of blasts. He received induction treatment with a 3 + 7 scheme (Citosar + Rubidomycin) after which the patient was in hematological remission with persistence of spinal fibrosis. Later, he started treatment with lenalidomide, bisphosphonates (Zoledronic Acid) and was in hematological remission 11 months after diagnosis, until March 2020. Histocompatibility studies (HLA) were performed for allogeneic transplantation(AU)

Significance of Targeted Sequencing Assay for Patients with Suspected Myeloid Malignancies / 中国实验血液学杂志

OBJECTIVE@#To investigate the clinical significance of the targeted next-generation sequencing assay for patients with suspected myeloid malignancies.@*METHODS@#A total of 39 hematopenia patients with suspected myeloid malignamies in Department of Hematology of The Affiliated Huai'an No.1 People's Hospital of Nanjing Medical University from January 2018 to April 2019 were treated, 20 hot spot genes of myelodysplastic syndrome (MDS) were detected.@*RESULTS@#Regarding the diagnostic type, there were 7 cases of idiopathic cytopenia of undetermined significance (ICUS), 8 cases of clonal cytopenias of undetermined significance (CCUS) and 24 cases of myeloid myeloid malignancies which included 18 cases of MDS, 4 cases of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) and 2 cases of acute myeloid leukemia. Positive mutation was detected in 70.8% (17/24) of myeloid malignancy patients , and 72.7% (16/22) in MDS and MDS/MPN patients. The main mutation types were ASXL1, TET2 and RUNX1. Compared with gene negative group, there were no significant differences in sex, age (＜60 years old or ≥60 years old), proportion of bone marrow blast cells (＜5% or≥5%) and cytogenetics (good, medium and poor) (P＞0.05). Furthermore, all 8 CCUS patients showed positive mutation, and the incidence of double or multiple mutation in CCUS group was significantly lower than that of the MDS and MDS/MPN group (37.5% vs 54.5%) (P=0.002). The mutation types between the two groups were similar, and there was no significant difference in variant allele frequency (P＞0.05).@*CONCLUSION@#Our results suggest that there are high rates of double or multiple mutations in myeloid malignancies, especially in patients with MDS and MDS/MPN. Targeted sequencing assay can improve the diagnosis of myeloid malignancies, and guide clinical treatment.

Biomarcadores en las neoplasias mieloproliferativas clásicas BCR-ABL1 negativas / Biomarkers in Classical Myeloproliferative Neoplasms BCR-ABL1 negative

Introducción: Los biomarcadores son útiles en la definición del diagnóstico, pronóstico y seguimiento de múltiples enfermedades. La detección o medición de uno o más biomarcadores específicos representan alteraciones en vías genéticas o epigenéticas que controlan la proliferación, diferenciación o muerte celular. Las neoplasias mieloproliferativas constituyen un grupo fenotípicamente diverso de hemopatías malignas de origen clonal, caracterizadas por una sobreproducción simple o multilineal de los elementos eritroides, mieloides y megacariocíticos; así como de una marcada predisposición a la trombosis, sangramiento y transformación leucémica. Dentro de ellas se incluyen: la policitemia vera, la trombocitemia esencial y la mielofibrosis primaria, conocidas como neoplasias mieloproliferativas clásicas BCR-ABL1 (o cromosoma Philadelfia) negativas. Las mutaciones somáticas en genes como JAK2, MPL y CARL se comportan como mutaciones drivers iniciadoras, responsables del fenotipo mieloproliferativo. Métodos: Se revisaron artículos relacionados publicados en los últimos años, en algunas bases de datos de la Biblioteca Virtual de Salud. En esta revisión se exponen los mecanismos moleculares generales de esas mutaciones y su expresión clínica; se hace referencia a las neoplasias mieloproliferativas triple negativas y sus implicaciones clínicas y se indica el algoritmo diagnóstico propuesto por la Organización Mundial de la Salud que incluye los nuevos biomarcadores. Conclusiones: El estudio molecular proporciona información valiosa para el diagnóstico y seguimiento de las neoplasias mieloprolifrativas, pero no logra diferenciar entre cada una de ellas. Por esto, se requiere de la adecuada aplicación del método clínico para llegar a un diagnóstico certero con ayuda de otros exámenes complementarios(AU)

Introduction: Biomarkers are useful in the definition of diagnosis, prognosis and monitoring of multiple diseases. The detection or measurement of one or more specific biomarkers represents alterations in genetic or epigenetic pathways that control proliferation, differentiation or cell death. The myeloproliferative neoplasms constitute a phenotypically diverse group of malignant hemopathies of clonal origin, characterized by a simple or multilinear overproduction of the erythroid, myeloid and megakaryocytic elements; as well as a marked predisposition to thrombosis, bleeding and leukemic transformation. These include: polycythemia vera, essential thrombocythemia, and primary myelofibrosis, known as classical negative myeloproliferative neoplasms BCR-ABL1 (or Philadelphia chromosome). Somatic mutations in genes such as JAK2, MPL and CARL behave as initiating driver mutations responsible for the myeloproliferative phenotype. Methods: Articles published in the last years were reviewed in some databases of the Virtual Health Library (VHL). In this review we expose the general molecular mechanisms of these mutations and their clinical expression; reference is made to the triple negative myeloproliferative neoplasms and their clinical implications and the diagnostic algorithm proposed by the World Health Organization that includes the new biomarkers is indicated. Conclusions: The molecular study provides valuable information for the diagnosis and monitoring of myeloproliferative neoplasms, but fails to differentiate between each of them. Therefore, the appropriate application of the clinical method is required to arrive at an accurate diagnosis with the help of other complementary tests(AU)

Calidad de vida en pacientes con neoplasias mieloproliferativas crónicas Filadélfia negativas / Quality of life in patients with Philadelphia negative chronic myeloproliferative neoplasms

Resumen Introducción: la carga sintomática de pacientes con neoplasias mieloproliferativas crónicas Filadélfia negativas (NMC-PhN) afecta la calidad de vida (CV). Existen escalas para evaluar la magnitud de los síntomas, una de ellas, MPN-SAF-10. En nuestra región existe escasa información sobre CV de pacientes con NMC-PhN. Objetivos: estimar el puntaje de calidad de vida con la escala MPN-SAF-10 en pacientes con NMC-PhN atendidos en el Hospital de San José (Bogotá, Colombia) y explorar asociaciones entre el tiempo de tratamiento, carga de complicaciones y el efecto en la CV. Material y métodos: estudio de corte transversal analítico para evaluar CV basada en carga sintomática de pacientes con NMC-PhN del Hospital de San José (Bogotá, Colombia). Se realizó análisis descriptivo y estratificado de calidad de vida, tratamiento citorreductor y de diferentes complicaciones, así como pruebas de asociación de los puntajes de riesgo de cada enfermedad con sus respectivos puntajes de CV. Resultados: en 64 pacientes la escala MPN-SAF-10 documentó medianas de puntajes globales de CV de 3 (RIC 1-6), MPN-SAF-10 de 20 (RIC 8-32). Un 49% de los pacientes tuvo algún grado de alteración (30% moderada y 19% severa), sin diferencias entre las tres enfermedades. Los puntajes de CV no variaron entre las NMC-PhN. El tratamiento y duración del mismo no se correlacionaron con la escala de MPN-SAF-10 (hidroxiúrea r: - 0.27; ruxolitinib r: 0.12). Conclusiones: en pacientes con NMC-PhN, la evaluación de CV con la escala MPN-SAF-10 evidencia algún grado de afectación a pesar del tratamiento; ésta es útil para objetivar dicha afectación y debe implementarse en la práctica clínica. (Acta Med Colomb 2019; 44: 82-90).

Abstract Introduction: the symptomatic burden of patients with Philadelphia negative chronic myelopro liferative neoplasms (NMC-PhN) affects the quality of life (QL). There are scales to evaluate the magnitude of the symptoms; one of them, MPN-SAF-10. In our region there is scarce information on QL of patients with NMC-PhN. Objectives: To estimate the quality of life score with the MPN-SAF-10 scale in patients with NMC-PhN treated at Hospital de San José (Bogotá, Colombia) and to explore associations between treatment time, complication load and the effect on the QL. Material and methods: Analytical cross-sectional study to evaluate QL based on symptomatic load of patients with NMC-PhN from Hospital de San José (Bogotá, Colombia). A descriptive and stratified analysis of quality of life, cytoreductive treatment and different complications was carried out, as well as association tests of the risk scores of each disease with their respective QL scores. Results: in 64 patients the MPN-SAF-10 scale documented medians of global QL scores of 3 (RIC 1-6), MPN-SAF-10 of 20 (RIC 8-32). 49% of the patients had some degree of alteration (30% moderate and 19% severe), without differences between the three diseases. The QL scores did not vary between the NMC-PhN. The treatment and its duration did not correlate with the MPN-SAF-10 scale (Hydroxyurea r: - 0.27, Ruxolitinib r: 0.12). Conclusions: in patients with NMC-PhN, the evaluation of QL with the MPN-SAF-10 scale shows some degree of affectation despite the treatment; this is useful to objectify this affectation and should be implemented in clinical practice. (Acta Med Colomb 2019; 44: 82-90).

Mutaciones en JAK2, MPL y CALR en neoplasias mieloproliferativas: análisis de disociación de alta resolución / Mutations in JAK2, MPL and CALR in myeloproliferative neoplasms: High Resolution Melting analysis / Mutações em JAK2, MPL e CALR em neoplasias mieloproliferativas: análise de dissociação em alta resolução

La policitemia vera (PV), la trombocitemia esencial (TE) y la mielofibrosis idiopática (MI) constituyen las Neoplasias Mieloproliferativas cromosoma Filadelfia negativas (NMP Ph-neg). La mutación V617F en el exón 14 del gen JAK2 ha sido descripta en un 90% de los casos de PV y en un 50% de TE y MI. Recientemente, se identificaron mutaciones en el exón 10 del gen MPL y en el exón 9 del gen CALR, presentes en un 5 y 73% de pacientes con TE y MI sin mutaciones en JAK2, respectivamente. En el presente trabajo se estudió la detección de dichas mutaciones en 52 pacientes con NMP, mediante amplificaciones por PCR en Tiempo Real con posterior análisis por High Resolution Melting (HRM) y secuenciación. La mutación V617F en JAK2 fue registrada en un 83,3% de pacientes con PV y 42,8% con TE y MI. Un 6,25% y 56,25% de pacientes con TE y MI JAK2 negativos resultaron positivos para mutaciones en el exón 10 de gen del receptor de la trombopoyetina (MPL) y el exón 9 de gen de la calreticulina (CALR). El análisis por HRM puede ser considerado como herramienta diagnóstica eficaz para las NMP debido a su alta sensibilidad, bajo costo y tiempo de procesado, teniendo en cuenta el impacto clínico que podría tener en los pacientes la detección temprana de dichas mutaciones.

Polycythemia vera (PV), essential thrombocythemia (TE) and idiopathic myelofibrosis (MI) are Philadelphia chromosome-negative myeloproliferative neoplasms (MPN-Ph. Neg). The presence of the V617F mutation in exon 14 of the JAK2 gene has been described in 90% of cases of PV and 50% of MI and TE. Recently, mutations in exon 10 of the MPL gene and exon 9 of CALR gene have been identified, which are present in 5 to 73% of patients with TE and MI without mutations in JAK2, respectively. In this work, the detection of these mutations was studied in 52 patients with NMP, using real time PCR amplifications with subsequent High Resolution Melting (HRM) analysis and sequencing. A total of 83.3% of patients with PV and 42.8% with MI and TE were recorded as positive for the V617F mutation in JAK2. A total of 6.25% and 56.25% of the patients with MI and TE with non-mutated JAK2 were positive for mutations in MPL exon 10 and CALR exon 9. HRM analysis could be considered an effective diagnostic tool for NMP due to its high sensitivity, low cost and processing time, taking into account the clinical impact that early detection of such mutations could have on patients.

Policitemia vera (PV), trombocitemia essencial (TE) e mielofibrose idiopática (MI) constituem as Neoplasias Mieloproliferativas cromossomo Filadélfia negativas (NMP Ph-neg). A mutação V617F no exon 14 do gene JAK2 foi descrita em 90% dos casos de PV e em 50% de TE e MI. Recentemente, foram identificadas mutações no exon 10 do gene MPL e no exon 9 do gene CALR, presentes em 5 a 73% de pacientes com TE e MI sem mutações em JAK2, respectivamente. Neste trabalho foi estudada a detecção de tais mutações em 52 pacientes com NMP, usando amplificações por PCR em Tempo Real, com posterior análise por High Resolution Melting (HRM) e sequenciamento. 83,3% dos pacientes com PV e 42,8% com TE e MI foram positivos para a mutação V617F em JAK2. 6,25% e 56,25% de pacientes com TE e MI JAK2 negativo foram positivos para mutações no exon 10 de gene do receptor da trombopoietina (MPL) e o exon 9 de gene da calreticulina (CALR). A análise por HRM pode ser considerada como ferramenta de diagnóstico eficaz para as NMP, devido à sua alta sensibilidade, baixo custo e tempo de processamento, tendo em conta o impacto clínico que poderia ter a detecção precoce de tais mutações nos pacientes.

Neoplasias mieloproliferativas. De la clínica a la biología molecular / Myeloproliferative neoplasms. From clinic to molecular biology

Las neoplasias mieloproliferativas (NMPs), son hemopatías clonales crónicas de la línea mieloide cuya anomalía se presenta a nivel de la célula madre hematopoyética en la médula ósea, llevando a una proliferación excesiva, expansión y acumulo de células mieloides sin bloqueo de la maduración o la función y se denominan de acuerdo con la línea predominante en la proliferación neoplásica ya sea eritroide, granulocítica o plaquetaria. El grado de expansión es variable a nivel de médula ósea (MO), sangre periférica y tejidos 1-3. Históricamente, la leucemia mieloide crónica (LMC) fue descrita de 1839 a 1845 por Alfred Donné, John Hughes y Robert Virchow. La mielofibrosis primitiva (MFP) por Gustav Heuck en 1879; Luis Henry Vaquez en unión con William Osler describieron por primera vez un caso de Policitemia Vera (PV) en 1892 y la tromobocitemia esencial (TE) fue descrita por Emil Epstein y Alfred Goedel en 1934. El término síndrome mieloproliferativo (SMP) fue propuesto por primera vez por el hematólogo Americano William Dameshek en 1951, quien describió las semejanzas de estas entidades en la evolución clínica 4,5. Una vez conocido el cromosoma Filadelfia en 1960, denominado así por los científicos Peter Noweel y David Hungerford por la localización geográfica de sus institutos de trabajo, se consideró aparte la leucemia mieloide crónica (LMC). La caracterización de la anomalía molecular del cromosoma Filadelfia en la LMC, la traslocación BCR-ABL fue hecha por Janet Rowley en 1973, y progresivamente se logró establecer que la fusión de ABL cuya actividad en estado natural implica regulación de la proliferación, adherencia y apoptosis se descontrola al fusionarse con el BCR 6. Se confirmó así la separación de la LMC de las neoplasias BCR-ABL negativas clásicas.

l-Amino acid oxidase isolated from calloselasma rhodostoma snake venom induces cytotoxicity and apoptosis in JAK2V617F-positive cell lines

BACKGROUND: Myeloproliferative neoplasms are Philadelphia chromosome-negative diseases characterized by hyperproliferation of mature myeloid cells, associated or not with the Janus kinase 2 tyrosine kinase mutation, JAK2V617F. As there is no curative therapy, researchers have been investigating new drugs to treat myeloproliferative neoplasms, including l-amino acid oxidase from Calloselasma rhodostoma snake venom (CR-LAAO), which is a toxin capable of eliciting apoptosis in several tumor cell lines. OBJECTIVE: To evaluate the effects of l-amino acid oxidase from C. rhodostoma snake venom in the apoptotic machinery of JAK2-mutated cell lines. METHODS: The HEL 92.1.7 and SET-2 cell lines were cultured with l-amino acid oxidase and catalase for 12 h at 37 °C in 5% carbon dioxide. The cell viability was assessed by the multi-table tournament method, the level of apoptosis was measured by flow cytometry, and the expression of cysteine-dependent aspartate-specific proteases and cleaved Poly(ADP-ribose) polymerase were analyzed by Western blotting. RESULTS: l-Amino acid oxidase from C. rhodostoma snake venom was cytotoxic to HEL 92.1.7 and SET-2 cells (50% inhibitory concentration = 0.15 µg/mL and 1.5 µg/mL, respectively) and induced apoptosis in a concentration-dependent manner. Cell treatment with catalase mitigated the l-amino acid oxidase toxicity, indicating that hydrogen peroxide is a key component of its cytotoxic effect.The activated caspases 3 and 8 expression and cleaved PARP in HEL 92.1.7 and SET-2 cells confirmed the apoptosis activation by CR-LAAO. CONCLUSIONS: l-Amino acid oxidase from C. rhodostoma snake venom is a potential antineoplastic agent against HEL 92.1.7 and SET-2 JAK2V617F-positive cells as it activates the extrinsic apoptosis pathway.

Expressão gênica de metaloproteinases e de seus reguladores em neoplasias mieloproliferativas: associação com biomarcadores de angiogênese e status mutacional / Gene expression of metalloproteinases and theirs regulators myeloproliferative neoplasms: association with angiogenesis markers and mutational status

As neoplasias mieloproliferativas (NMPs) BCR-ABL1 negativas compreendem a mielofibrose primária (PMF), trombocitemia essencial (TE) e a policitemia vera (PV). A patogênese e progressão dessas NMPs não estão completamente elucidadas. As metaloproteinases de matriz (MMPs) degradam a matriz extracelular, ativando citocinas e fatores de crescimento que, por sua vez, participam da tumorigênese e angiogênese. O objetivo deste estudo foi avaliar a relação da expressão gênica das MMPs, TIMPs, HIF1-α e SPARC com os marcadores angiogênicos bFGF e VEGFA em pacientes com MF e TE, considerando o status mutacional; bem como avaliar a regulação desses genes em camundongos submetidos à hipóxia, e em modelos HIF1-α(-/-) e VHL(-/-). Foram incluídos 21 pacientes com MF, 21 com MF pós-TE, 6 com MF pós-PV, 23 com TE e 78 indivíduos controle. As análises realizadas foram: dosagem sérica e expressão de RNAm de MMP2, MMP9, TIMP1, TIMP2 e SPARC, hemograma, determinação da proteína C reativa ultrassensível, determinação das concentrações de VEGFA e bFGF e avaliação das mutações nos genes JAK2, cMPL e CALR. A avaliação da densidade microvascular da medula óssea foi feita em 30 dos pacientes incluídos. Os pacientes com MFP, MFPTE e TE apresentaram maior expressão de MMP2, SPARC, TIMP1, TIMP2 e bFGF quando comparados aos seus controles (P<0,05), enquanto MMP9 foi mais expressa nos pacientes com MFPTE e TE (P= 0,011 e P=0,047, respectivamente). Os pacientes com TE apresentaram maior expressão de HIF1-α e VEGFA em relação ao grupo controle (P<0,05). Pacientes com MF JAK2V617F positivos apresentaram maiores concentrações de MMP9, TIMP2, bFGF e VEGFA quando comparados aos pacientes portadores de mutações na CALR (P<0,05). Os pacientes com TE JAK2V617F positivos apresentaram maiores concentrações de MMP2 e TIMP2 (P=0,049 e P=0,020, respectivamente). As concentrações das proteínas estudadas não apresentaram correlação com a carga alélica de JAK2V617F e nem com a densidade microvascular da medula óssea. Células de medula óssea de camundongos submetidos à hipóxia apresentaram maior expressão de MMP2 e TIMP1 comparados aos camundongos em normóxia. Camundongos VHL(-/-) apresentaram aumento na expressão dos genes MMP2, MMP9, TIMP1, TIMP2 e VEGFA. Diferentemente, embriões HIF1-α(-/-) não foram considerados um bom modelo para este estudo devido ao envolvimento das MMPs na embriogênese/organogênese. Frente aos resultados encontrados, pode-se sugerir que a maior expressão de MMP2, SPARC e de bFGF estão associadas às NMPs. A mutação JAK2V617F foi associada a maiores concentrações de MMPs, TIMP2 VEGFA e bFGF. HIF1-α foi mais expresso na PV e na TE, sugerindo uma possível regulação da expressão das MMPs e TIMPs nessas doenças

Myeloproliferative neoplasms (MPNs) BCR-ABL1-negative include primary myelofibrosis (PMF), essential thrombocythemia (ET) and polycythemia vera (PV). The mechanisms underlying the pathology and disease progression in MPN are not completely elucidated. The matrix metalloproteinases (MMPs) cleave extracellular matrix, activating cytokines and growth factors that, in turn, regulate tumorigenesis and angiogenesis. The aim of this study was to evaluate the relationship of MMPs, TIMPs, HIF1-α and SPARC gene expression with angiogenic markers bFGF and VEGFA in patients with MPN considering their mutational status; as well as to assess the regulation of these genes in animal models HIF1-α and VHL knockouts. Twenty-one MF, 21 MF post-ET, 6 MF post-PV, 23 ET patients and 78 controls were enrolled. The analysis performed in peripheral blood were: serum and mRNA expression of MMP2, MMP9, TIMP1, TIMP2 and SPARC, blood count, high-sensitivity C-reactive protein determination and VEGFA and bFGF measurements in plasma. We also evaluate mutations in JAK2, MPL and CALR. The assessment of microvascular density (MVD) in bone marrow was performed in 30 patients. Patients with MFP, MFPET and ET presented higher expression of MMP2, SPARC, TIMP1, TIMP2 and bFGF compared to their controls (P <0.05), while MMP9 expression was higher in patients with MFPET and ET (P=0.011 and P=0.047, respectively). Higher expression of HIF1-α and VEGFA was found in ET patients compared to the controls (P <0.05). PMF JAK2V617F patients had higher concentrations of MMP9, TIMP2, bFGF and VEGFA compared to CALR mutated ones (P <0.05). ET patients JAK2V617F positive had higher levels of MMP2 and TIMP2 (P=0.049 and P=0.020, respectively). The JAK2V617F allele burden was not associated with MVD in the bone marrow. Bone marrow cells from mice in hypoxia condition showed higher MMP2 and TIMP1 expression compared to the control. VHL(-/-) mice exhibited increased expression of MMP2, MMP9, TIMP1, TIMP2 and VEGFA. In contrast, the HIF1-α(-/-) embryos were not considered an applicable model for this study due to MMPs role in embryogenesis/organogenesis. In view of these findings, we can conclude that increased expression of MMP2, SPARC and bFGF are associated with MPN. The JAK2V617F mutation was associated with higher concentrations of MMPs, TIMP2 VEGFA and bFGF. HIF1-α is upregulated in PV and ET and perhaps regulate the MMPs and TIMPs expression in these diseases

Myeloproliferative neoplasms and the JAK/STAT signaling pathway: an overview

ABSTRACTMyeloproliferative neoplasms are caused by a clonal proliferation of a hematopoietic progenitor. First described in 1951 as 'Myeloproliferative Diseases' and reevaluated by the World Health Organization classification system in 2011, myeloproliferative neoplasms include polycythemia vera, essential thrombocythemia and primary myelofibrosis in a subgroup called breakpoint cluster region-Abelson fusion oncogene-negative neoplasms. According to World Health Organization regarding diagnosis criteria for myeloproliferative neoplasms, the presence of the JAK2 V617F mutation is considered the most important criterion in the diagnosis of breakpoint cluster region-Abelson fusion oncogene-negative neoplasms and is thus used as a clonal marker. The V617F mutation in the Janus kinase 2(JAK2) gene produces an altered protein that constitutively activates the Janus kinase/signal transducers and activators of transcription pathway and other pathways downstream as a result of signal transducers and activators of transcription which are subsequently phosphorylated. This affects the expression of genes involved in the regulation of apoptosis and regulatory proteins and modifies the proliferation rate of hematopoietic stem cells.

A model for the functional assessment of elderly with myeloid neoplasms

Objective: Myeloid neoplasms are heterogeneous diseases that are more incident in the elderly. The goals of this study were to aggregate a geriatric approach to the patient assessment, to show the impact of gender, age, hemoglobin concentration and comorbidities on the functionality of elderly with myeloid neoplasms and to better understand how the instruments of functional assessment work according to the aggressiveness of the disease. Methods: Elderly patients (≥60 years old) with myeloid neoplasms were assessed using the Karnofsky scale, Eastern Cooperative Oncologic Group scale, and basic and instru- mental activities of daily living scales. The hematopoietic cell transplantation-comorbidity index assessed the comorbidities. A mixed logistical regression model was fitted to estimate the impact of gender, age, hemoglobin concentration and the hematopoietic cell transplantation-comorbidity index on patients' functionality. Results: Eighty-two patients with a mean age of 72.8 years (range: 60-92 years) were evaluated. Eighty percent had good Karnofsky and Eastern Cooperative Oncologic Group scales and 39% were independent according to the daily living activity scales. All of the patients with poor Karnofsky and Eastern Cooperative Oncologic Group scales were classified as dependent by the daily living activity scales. The mixed logistic regression models showed that age, gender, hemoglobin concentration and the comorbidity index impacted on the daily living activity scales. Karnofsky and Eastern Cooperative Oncologic Group scales were affected by hemoglobin and the comorbidity index. The model hypothesized the hemoglobin concentration at which there was a higher risk of poor Karnofsky and Eastern Cooperative Oncologic Group scales. This hemoglobin concentration depended on comorbidities and on the aggressiveness of the myeloid neoplasm. Conclusion: The geriatric approach improved the sensitivity and specificity ...

Analysis of Differentially Expressed Signaling Pathway Proteins in Myelodysplastic/Myeloproliferative Neoplasms-Unclassifiable / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To screen signaling pathway proteins in myelodysplastic/myeloproliferative neoplasms-unclassifiable (MDS/MPN-U), and to explore the possible role of the differentially expressed signaling pathway proteins in pathogenesis of MDS/MPN-U.</p><p><b>METHODS</b>Protein Pathway Array (PPA) was applied to analyze the differential expression levels of signaling pathway proteins in 10 patients with MDS/MPN-U and normal controls, and furthermore to identify the signaling pathways and network in which these proteins were analyzed by Ingenuity pathway analysis program.</p><p><b>RESULTS</b>The expressions of 25 signaling proteins in MDS/MPN-U were significantly different, compared with the control group. Among them 15 proteins were upregulated in MDS/MPN-U patients, while 10 proteins were downregulated. These dysregulated proteins were involved in 10 major signaling pathways related with cell proliferation and immunity. The complicated interactive network was established by these proteins and pathways.</p><p><b>CONCLUSION</b>The differentially expressed signaling proteins screened from the MDS/MPN-U patients by PPA might be helpful to reveal the pathogenesis of MDS/MPN-U and to discover the therapeutic targets.</p>

Quantification of mixed chimerism allows early therapeutic interventions

Hematopoietic stem cell transplantation is the curative option for patients with myelodysplastic syndrome; however, it requires a long post-transplantation follow-up. A 53-year-old woman with a diagnosis of myelodysplastic syndrome underwent related donor allogeneic hematopoietic stem cell transplantation in July 2006. Three months after transplantation, a comparative short tandem repeat analysis between donor and recipient revealed full chimerism, indicating complete, healthy bone marrow reconstitution. Three years and ten months after hematopoietic stem cell transplantation, the patient developed leukopenia and thrombocytopenia. Another short tandem repeat analysis was carried out which showed mixed chimerism (52.62%), indicating relapsed disease. A donor lymphocyte infusion was administered. The purpose of donor lymphocyte infusion is to induce a graft-versus-leukemia effect; in fact, this donor's lymphocyte infusion induced full chimerism. Successive short tandem repeat analyses were performed as part of post-transplantation follow-up, and in July 2010, one such analysis again showed mixed chimerism (64.25%). Based on this finding, a second donor lymphocyte infusion was administered, but failed to eradicate the disease. In September 2011, the patient presented with relapsed disease, and a second related donor allogeneic hematopoietic stem cell transplantation was performed. Subsequent short tandem repeat analyses revealed full chimerism, indicating complete bone marrow reconstitution. We conclude that quantitative detection of mixed chimerism is an important diagnostic tool that can guide early therapeutic intervention...

Desregulação da apoptose em neoplasias mieloproliferativas crônicas / Apoptosis deregulation in myeloproliferative neoplasms

As neoplasias mieloproliferativas crônicas cromossomo Filadélfia negativas são doenças hematológicas clonais que se caracterizam pela independência ou pela hipersensibilidade dos progenitores hematopoiéticos às citocinas. Os mecanismos celulares e moleculares envolvidos na fisiopatologia das neoplasias mieloproliferativas crônicas ainda não estão totalmente esclarecidos. Achados fisiopatológicos relevantes para as neoplasias mieloproliferativas crônicas estão associados às alterações genéticas como, por exemplo, a mutação somática no gene que codifica o JAK2 (JAK2V617F). A desregulação do processo de morte celular programada, denominada apoptose, parece participar da patogênese dessas desordens. Sabe-se que a desregulação da expressão dos genes pró- e antiapoptóticos promove a resistência das células à apoptose, culminando com o acúmulo das células mieloides e estabelecendo a neoplasia. Esta revisão enfocou as alterações na regulação da apoptose em neoplasias mieloproliferativas crônicas e a importância da melhor compreensão desse mecanismo para o desenvolvimento de novas terapias para essas doenças.

Philadelphia-chromosome negative chronic myeloproliferative neoplasms are clonal hematologic diseases characterized by hematopoietic progenitor independence from or hypersensitivity to cytokines. The cellular and molecular mechanisms involved in the pathophysiology of myeloproliferative neoplasms have not yet been fully clarified. Pathophysiologic findings relevant for myeloproliferative neoplasms are associated with genetic alterations, such as, somatic mutation in the gene that codifies JAK-2 (JAK V617F). Deregulation of the process of programmed cellular death, called apoptosis, seems to participate in the pathogenesis of these disorders. It is known that expression deregulation of pro- and anti-apoptotic genes promotes cell resistance to apoptosis, culminating with the accumulation of myeloid cells and establishing neoplasms. This review will focus on the alterations in apoptosis regulation in myeloproliferative neoplasms, and the importance of a better understanding of this mechanism for the development of new therapies for these diseases.

Atypical chronic myeloid leukemia with t(9; 22)(p24,11. 2), a BCR-JAK2 fusion gene

We report here on a rare case of BCR-ABL1-negative atypical chronic myeloid leukemia with a t(9;22)(p24;q11.2)translocation and a BCR-JAK2 fusion gene, with resistance to the tyrosine kinase inhibitors imatinib and dasatinib.At two years of follow-up, the patient showed no hematologic response and was submitted to an allogeneic bonemarrow transplantation. Fifty-three days after the procedure, he died due to acute graft-versus-host disease. This BCR-JAK2 fusion gene has so far been found in only five patients in the whole world, with three clinical presentations: myeloproliferative neoplasm, acute lymphoblastic leukemia and acute myeloid leukemia.