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Background: The Inspiration4 (I4) mission, the first all-civilian orbital flight mission, investigated the physiological effects of short-duration spaceflight through a multi-omic approach. Despite advances, there remains much to learn about human adaptation to spaceflight's unique challenges, including microgravity, immune system perturbations, and radiation exposure. Methods: To provide a detailed genetics analysis of the mission, we collected dried blood spots pre-, during, and post-flight for DNA extraction. Telomere length was measured by quantitative PCR, while whole genome and cfDNA sequencing provided insight into genomic stability and immune adaptations. A robust bioinformatic pipeline was used for data analysis, including variant calling to assess mutational burden. Result: Telomere elongation occurred during spaceflight and shortened after return to Earth. Cell-free DNA analysis revealed increased immune cell signatures post-flight. No significant clonal hematopoiesis of indeterminate potential (CHIP) or whole-genome instability was observed. The long-term gene expression changes across immune cells suggested cellular adaptations to the space environment persisting months post-flight. Conclusion: Our findings provide valuable insights into the physiological consequences of short-duration spaceflight, with telomere dynamics and immune cell gene expression adapting to spaceflight and persisting after return to Earth. CHIP sequencing data will serve as a reference point for studying the early development of CHIP in astronauts, an understudied phenomenon as previous studies have focused on career astronauts. This study will serve as a reference point for future commercial and non-commercial spaceflight, low Earth orbit (LEO) missions, and deep-space exploration.
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Clonal hematopoiesis (CH) represents clonal expansion of mutated hematopoietic stem cells detectable in the peripheral blood or bone marrow through next generation sequencing. The current prevailing model posits that CH mutations detected in the peripheral blood mirror bone marrow mutations with clones widely disseminated across hematopoietic compartments. We sought to test the hypothesis that all clones are disseminated throughout hematopoietic tissues by comparing CH in hip vs peripheral blood specimens collected at the time of hip replacement surgery. Here, we show that patients with osteoarthritis have a high prevalence of CH, which involve genes encoding epigenetic modifiers and DNA damage repair pathway proteins. Importantly, we illustrate that CH, including clones with variant allele frequencies >10%, can be confined to specific bone marrow spaces and may be eliminated through surgical excision. Future work will define whether clones with somatic mutations in particular genes or clonal fractions of certain sizes are either more likely to be localized or are slower to disseminate into the peripheral blood and other bony sites.
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Médula Ósea , Hematopoyesis Clonal , Humanos , Hematopoyesis/genética , Células Madre Hematopoyéticas/metabolismo , Células ClonalesRESUMEN
The role of intratumor heterogeneity is becoming increasingly apparent in part due to expansion in single cell technologies. Clinically, tumor heterogeneity poses several obstacles to effective cancer therapy dealing with biomarker variability and treatment responses. Matrix stiffening is known to occur during tumor progression and contribute to pathogenesis in several cancer hallmarks, including tumor angiogenesis and metastasis. However, the effects of matrix stiffening on intratumor heterogeneity have not been thoroughly studied. In this study, we applied single-cell RNA sequencing to investigate the differences in the transcriptional landscapes between stiff and compliant MMTV-PyMT mouse mammary tumors. We found similar compositions of cancer and stromal subpopulations in compliant and stiff tumors but differential intercellular communication and a significantly higher concentration of tumor-promoting, M2-like macrophages in the stiffer tumor microenvironments. Interestingly, we found that cancer cells seeded on stiffer substrates recruited more macrophages. Furthermore, elevated matrix stiffness increased Colony Stimulating Factor 1 (CSF-1) expression in breast cancer cells and reduction of CSF-1 expression on stiffer substrates reduced macrophage recruitment. Thus, our results demonstrate that tissue phenotypes were conserved between stiff and compliant tumors but matrix stiffening altered cell-cell interactions which may be responsible for shifting the phenotypic balance of macrophages residing in the tumor microenvironment towards a pro-tumor progression M2 phenotype. STATEMENT OF SIGNIFICANCE: Cells within tumors are highly heterogeneous, posing challenges with treatment and recurrence. While increased tissue stiffness can promote several hallmarks of cancer, its effects on tumor heterogeneity are unclear. We used single-cell RNA sequencing to investigate the differences in the transcriptional landscapes between stiff and compliant MMTV-PyMT mouse mammary tumors. We found similar compositions of cancer and stromal subpopulations in compliant and stiff tumors but differential intercellular communication and a significantly higher concentration of tumor-promoting, M2-like macrophages in the stiffer tumor microenvironments. Using a biomaterial-based platform, we found that cancer cells seeded on stiffer substrates recruited more macrophages, supporting our in vivo findings. Together, our results demonstrate a key role of matrix stiffness in affecting cell-cell communication and macrophage recruitment.
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Factor Estimulante de Colonias de Macrófagos , Neoplasias Mamarias Animales , Animales , Ratones , Factor Estimulante de Colonias de Macrófagos/metabolismo , Microambiente Tumoral , Macrófagos/metabolismo , Comunicación Celular , Neoplasias Mamarias Animales/patología , Línea Celular TumoralRESUMEN
Acute myeloid leukemia (AML) is a disease with high incidence of relapse that is originated and maintained from leukemia stem cells (LSCs). Hematopoietic stem cells can be distinguished from LSCs by an array of cell surface antigens such as CD123, thus a candidate to eliminate LSCs using a variety of approaches, including CAR T cells. Here, we evaluate the potential of allogeneic gene-edited CAR T cells targeting CD123 to eliminate LSCs (UCART123). UCART123 cells are TCRαßneg T cells generated from healthy donors using TALEN® gene-editing technology, decreasing the likelihood of graft vs host disease. As safety feature, cells express RQR8 to allow elimination with Rituximab. UCART123 effectively eliminates AML cells in vitro and in vivo with significant benefits in overall survival of AML-patient derived xenograft mice. Furthermore, UCART123 preferentially target AML over normal cells with modest toxicity to normal hematopoietic stem/progenitor cells. Together these results suggest that UCART123 represents an off-the shelf therapeutic approach for AML.
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Trasplante de Células Madre Hematopoyéticas , Leucemia Mieloide Aguda , Animales , Humanos , Subunidad alfa del Receptor de Interleucina-3/metabolismo , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/terapia , Ratones , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Receptores de Antígenos de Linfocitos T alfa-beta/metabolismo , Linfocitos TRESUMEN
PURPOSE: Hematologic toxic effects of peptide receptor radionuclide therapy (PRRT) can be permanent. Patients with underlying clonal hematopoiesis (CH) may be more inclined to develop hematologic toxicity after PRRT. However, this association remains understudied. MATERIALS AND METHODS: We evaluated pre- and post-PRRT blood samples of patients with neuroendocrine tumors. After initial screening, 13 cases of interest were selected. Serial blood samples were obtained on 4 of 13 patients. Genomic DNA was analyzed using a 100-gene panel. A variant allele frequency cutoff of 1% was used to call CH. RESULT: Sixty-two percent of patients had CH at baseline. Persistent cytopenias were noted in 64% (7 of 11) of the patients. Serial sample analysis demonstrated that PRRT exposure resulted in clonal expansion of mutant DNA damage response genes (TP53, CHEK2, and PPM1D) and accompanying cytopenias in 75% (3 of 4) of the patients. One patient who had a normal baseline hemogram and developed persistent cytopenias after PRRT exposure showed expansion of mutant PPM1D (variant allele frequency increased to 20% after exposure from < 1% at baseline). In the other two patients, expansion of mutant TP53, CHEK2, and PPM1D clones was also noted along with cytopenia development. CONCLUSION: The shifts in hematopoietic clonal dynamics in our study were accompanied by emergence and persistence of cytopenias. These cytopenias likely represent premalignant state, as PPM1D-, CHEK2-, and TP53-mutant clones by themselves carry a high risk for transformation to therapy-related myeloid neoplasms. Future studies should consider CH screening and longitudinal monitoring as a key risk mitigation strategy for patients with neuroendocrine tumors receiving PRRT.
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Hematopoyesis Clonal/genética , Hematopoyesis , Sistema Hematopoyético , Tumores Neuroendocrinos/sangre , Tumores Neuroendocrinos/genética , Tumores Neuroendocrinos/radioterapia , Proteína Fosfatasa 2C/genética , Radioisótopos/efectos adversos , Receptores de Péptidos , Proteína p53 Supresora de Tumor/fisiología , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Radioisótopos/uso terapéutico , Radioterapia/efectos adversosRESUMEN
B-cell acute lymphoblastic leukemia (B-ALL) results from the expansion of malignant lymphoid precursors within the bone marrow (BM), where hematopoietic niches and microenvironmental signals provide leukemia-initiating cells (LICs) the conditions to survive, proliferate, initiate disease, and relapse. Normal and malignant lymphopoiesis are highly dependent on the BM microenvironment, particularly on CXCL12-abundant Reticular (CAR) cells, which provide a niche for maintenance of primitive cells. During B-ALL, leukemic cells hijack BM niches, creating a proinflammatory milieu incompetent to support normal hematopoiesis but favoring leukemic proliferation. Although the lack of a phenotypic stem cell hierarchy is apparent in B-ALL, LICs are a rare and quiescent population potentially responsible for chemoresistance and relapse. Here, we developed novel patient-derived leukemia spheroids (PDLS), an ex vivo avatar model, from mesenchymal stromal cells (MSCs) and primary B-ALL cells, to mimic specialized niche structures and cell-to-cell intercommunication promoting normal and malignant hematopoiesis in pediatric B-ALL. 3D MSC spheroids can recapitulate CAR niche-like hypoxic structures that produce high levels of CXCL10 and CXCL11. We found that PDLS were preferentially enriched with leukemia cells displaying functional properties of LICs, such as quiescence, low reactive oxygen species, drug resistance, high engraftment in immunodeficient mice, and long-term leukemogenesis. Moreover, the combination of PDLS and patient-derived xenografts confirmed a microenvironment-driven hierarchy in their leukemic potential. Importantly, transcriptional profiles of MSC derived from primary patient samples revealed two unique signatures (1), a CXCL12low inflammatory and leukemia expansion (ILE)-like niche, that likely supports leukemic burden, and (2) a CXCL11hi immune-suppressive and leukemia-initiating cell (SLIC)-like niche, where LICs are likely sustained. Interestingly, the CXCL11+ hypoxic zones were recapitulated within the PDLS that are capable of supporting LIC functions. Taken together, we have implemented a novel PDLS system that enriches and supports leukemia cells with stem cell features driven by CXCL11+ MSCs within hypoxic microenvironments capable of recapitulating key features, such as tumor reemergence after exposure to chemotherapy and tumor initiation. This system represents a unique opportunity for designing ex vivo personalized avatars for B-ALL patients to evaluate their own LIC pathobiology and drug sensitivity in the context of the tumor microenvironment.
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Células Madre Neoplásicas/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Esferoides Celulares , Nicho de Células Madre , Células Tumorales Cultivadas , Animales , Médula Ósea/patología , Femenino , Xenoinjertos , Humanos , Células Madre Mesenquimatosas/patología , Ratones , Microambiente TumoralRESUMEN
The epichaperome is a new cancer target composed of hyperconnected networks of chaperome members that facilitate cell survival. Cancers with an altered chaperone configuration may be susceptible to epichaperome inhibitors. We developed a flow cytometry-based assay for evaluation and monitoring of epichaperome abundance at the single cell level, with the goal of prospectively identifying patients likely to respond to epichaperome inhibitors, to measure target engagement, and dependency during treatment. As proof of principle, we describe a patient with an unclassified myeloproliferative neoplasm harboring a novel PML-SYK fusion, who progressed to acute myeloid leukemia despite chemotherapy and allogeneic stem cell transplant. The leukemia was identified as having high epichaperome abundance. We obtained compassionate access to an investigational epichaperome inhibitor, PU-H71. After 16 doses, the patient achieved durable complete remission. These encouraging results suggest that further investigation of epichaperome inhibitors in patients with abundant baseline epichaperome levels is warranted.
RESUMEN
Clonal hematopoiesis (CH) occurs when blood cells harboring an advantageous mutation propagate faster than others. These mutations confer a risk for hematological cancers and cardiovascular disease. Here, we analyze CH in blood samples from a pair of twin astronauts over 4 years in bulk and fractionated cell populations using a targeted CH panel, linked-read whole-genome sequencing, and deep RNA sequencing. We show CH with distinct mutational profiles and increasing allelic fraction that includes a high-risk, TET2 clone in one subject and two DNMT3A mutations on distinct alleles in the other twin. These astronauts exhibit CH almost two decades prior to the mean age at which it is typically detected and show larger shifts in clone size than age-matched controls or radiotherapy patients, based on a longitudinal cohort of 157 cancer patients. As such, longitudinal monitoring of CH may serve as an important metric for overall cancer and cardiovascular risk in astronauts.
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Hematopoyesis Clonal/genética , Hematopoyesis Clonal/fisiología , Ingravidez/efectos adversos , Adulto , Astronautas , Células Clonales , ADN (Citosina-5-)-Metiltransferasas/genética , ADN Metiltransferasa 3A , Proteínas de Unión al ADN/genética , Dioxigenasas/genética , Femenino , Neoplasias Hematológicas/genética , Hematopoyesis/genética , Hematopoyesis/fisiología , Humanos , Masculino , Persona de Mediana Edad , Mutación/genética , Neoplasias/genética , Factores de Riesgo , Vuelo Espacial , Factores de TiempoRESUMEN
OBJECTIVES: Crystal-storing histiocytosis (CSH) is rare in plasma cell dyscrasias, with only 3 cases reported in the setting of amyloid. No cases of crystal-negative histiocytosis coincident with multiple myeloma and amyloidosis have been reported previously. METHODS: A 58-year-old woman presented with pain due to destructive bone lesions and was found to have plasma cell myeloma (PCM) and marrow amyloid deposition associated with crystal-negative histiocytosis. Differential diagnoses included Langerhans cell histiocytosis, Erdheim-Chester disease, and Rosai Dorfman disease. BRAF mutations were negative, and there was no evidence of paraprotein crystals, arguing against typical CSH. RESULTS: The patient was treated with bortezomib, cyclophosphamide, and dexamethasone, and she subsequently underwent autologous stem cell transplant and ixazomib maintenance. She achieved complete remission with improvement of her symptoms and preserved remission after following up at 60 months. CONCLUSIONS: We describe a case of crystal-negative histiocytosis associated with PCM. CSH is a rare disorder associated with paraprotein-producing conditions in which immunoglobulins aggregate as intracellular crystals in the lysosomes of organ-specific phagocytic macrophages. Light chain tropism in PCM can also lead to the development of amyloid deposition in organs and, in rare cases, is associated with light chain aggregation as intracellular crystals in macrophages.
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Amiloide/análisis , Médula Ósea/química , Histiocitosis/patología , Mieloma Múltiple/diagnóstico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Médula Ósea/patología , Bortezomib/administración & dosificación , Cristalización , Ciclofosfamida/administración & dosificación , Dexametasona/administración & dosificación , Diagnóstico Diferencial , Femenino , Humanos , Persona de Mediana Edad , Mieloma Múltiple/patología , Mieloma Múltiple/terapia , Inducción de Remisión , Trasplante de Células MadreRESUMEN
Clonal hematopoiesis (CH) arises when mutations in the hematopoietic system confer a fitness advantage to specific clones, thereby favoring their disproportionate growth. The presence of CH increases with age and environmental exposures such as cytotoxic chemotherapy or radiotherapy. The most frequent mutations occur in epigenetic regulators, such as DNMT3A, TET2, and ASXL1, leading to dysregulation of tumor suppressor function, pathogen response, and inflammation. These dysregulated processes elevate risk of overall mortality, cardiovascular disease, and eventual hematologic malignancy (HM). CH is likely acting as an initiating event leading to HM when followed by cooperating mutations. However, further evidence suggests that CH exerts a bystander influence through its pro-inflammatory properties. Delineating the mechanisms that lead to the onset and expansion of CH as well as its contribution to risk of HM is crucial to defining a management and intervention strategy. In this review, we discuss the potential causes, consequences, technical considerations, and possible management strategies for CH in the context of HMs and pre-HMs.
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Hematopoyesis Clonal/genética , Neoplasias Hematológicas/patología , Células Madre Hematopoyéticas/patología , Leucemia/patología , Lesiones Precancerosas/patología , Animales , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/metabolismo , Neoplasias Hematológicas/terapia , Células Madre Hematopoyéticas/metabolismo , Humanos , Leucemia/genética , Leucemia/metabolismo , Leucemia/terapia , Mutación , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Lesiones Precancerosas/genética , Lesiones Precancerosas/metabolismoRESUMEN
Novel treatment strategies are needed for older patients with acute myeloid leukemia (AML). This randomized phase 2 trial compared the efficacy and safety of 20 mg/m2 of IV decitabine on days 1 to 10 alone (arm A) with those of 1.3 mg/m2 of subcutaneous bortezomib (arm B) on days 1, 4, 8, and 11 for up to 4 10-day cycles followed by monthly 5-day cycles. Previously untreated AML patients age ≥60 years (excluding those with FLT3 mutations and favorable-risk cytogenetics) without restrictions in performance status (PS) or organ function were eligible. Median age was 72.4 years (range, 60.5-92.3 years); 31 patients (19%) had baseline PS ≥2, 35 (22%) had an antecedent hematological disorder, 58 had (39%) adverse cytogenetics, and 7 (5%) and 23 (14%) had abnormal cardiac or renal function. There were no statistically significant differences in overall survival (OS) or responses between the 2 treatment arms. The overall response rate (complete remission + complete remission with incomplete blood count recovery) was 39% (n = 64), with median OS of 9.3 months. Nineteen responders (31%) underwent allogeneic stem cell transplantation. The most common adverse event was febrile neutropenia, and there were no unexpected toxicities. Adding bortezomib to decitabine did not improve outcomes, but responses were better than those in previous trials using 5-day decitabine cycles. This trial was registered at www.clinicaltrials.gov as #NCT01420926.
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Antineoplásicos/uso terapéutico , Bortezomib/uso terapéutico , Decitabina/uso terapéutico , Leucemia Mieloide Aguda/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Supervivencia sin Enfermedad , Esquema de Medicación , Quimioterapia Combinada , Femenino , Humanos , Estimación de Kaplan-Meier , Leucemia Mieloide Aguda/mortalidad , Masculino , Persona de Mediana Edad , Mutación , Proteínas Represoras/genética , Resultado del Tratamiento , Proteína p53 Supresora de Tumor/genéticaRESUMEN
The pattern of somatic mutations observed at diagnosis of acute myeloid leukemia (AML) has been well-characterized. However, the premalignant mutational landscape of AML and its impact on risk and time to diagnosis is unknown. Here we identified 212 women from the Women's Health Initiative who were healthy at study baseline, but eventually developed AML during follow-up (median time: 9.6 years). Deep sequencing was performed on peripheral blood DNA of these cases and compared to age-matched controls that did not develop AML. We discovered that mutations in IDH1, IDH2, TP53, DNMT3A, TET2 and spliceosome genes significantly increased the odds of developing AML. All subjects with TP53 mutations (n = 21 out of 21 patients) and IDH1 and IDH2 (n = 15 out of 15 patients) mutations eventually developed AML in our study. The presence of detectable mutations years before diagnosis suggests that there is a period of latency that precedes AML during which early detection, monitoring and interventional studies should be considered.
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Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/genética , Mutación/genética , Alelos , Estudios de Casos y Controles , Evolución Clonal , Progresión de la Enfermedad , Femenino , Humanos , Leucemia Mieloide Aguda/sangre , Análisis Multivariante , Tasa de Mutación , Oportunidad Relativa , Factores de RiesgoRESUMEN
Acute myeloid leukemia carries a dismal prognosis in older patients. The objective of this study was to investigate the safety and efficacy of decitabine combined with the CXCR4 antagonist plerixafor in newly diagnosed older patients with acute myeloid leukemia and to evaluate the effects of plerixafor on leukemia stem cells. Patients were treated with monthly cycles of decitabine 20 mg/m2 days 1-10 and escalating doses of plerixafor (320-810 mcg/kg) days 1-5. Sixty-nine patients were treated, with an overall response rate of 43%. Adverse karyotype did not predict response (P=0.31). Prior hypomethylating agent treatment was the strongest independent predictor of adverse overall survival (hazard ratio 3.1; 95%CI: 1.3-7.3; P=0.008) and response (14% in previously treated patients, 46% in treatment naïve; P=0.002). As expected, the most common toxicities were myelosuppression and infection. Plerixafor induced mobilization of leukemia stem and progenitor cells, but did not cause clinically significant hyperleukocytosis. Reduction in leukemia stem cells appeared to correlate with duration of response. Plerixafor can be safely added to decitabine in poor-prognosis, elderly acute myeloid leukemia patients. The maximum tolerated dose of the combination was 810 mcg/kg. While mobilization of leukemia stem cells was observed in some patients, the clinical benefit of adding plerixafor was uncertain. This trial was registered at clinicaltrials.gov identifier: 01352650.
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Compuestos Heterocíclicos/uso terapéutico , Leucemia Mieloide Aguda/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Bencilaminas , Movimiento Celular , Ciclamas , Decitabina/uso terapéutico , Femenino , Humanos , Leucemia Mieloide Aguda/mortalidad , Leucemia Mieloide Aguda/patología , Masculino , Dosis Máxima Tolerada , Persona de Mediana Edad , Receptores CXCR4/antagonistas & inhibidores , Resultado del TratamientoAsunto(s)
Anticuerpos Monoclonales/inmunología , Antineoplásicos Inmunológicos/uso terapéutico , Subunidad alfa del Receptor de Interleucina-3/análisis , Leucemia Mieloide Aguda/inmunología , Citometría de Flujo , Humanos , Inmunofenotipificación/métodos , Subunidad alfa del Receptor de Interleucina-3/antagonistas & inhibidores , Subunidad alfa del Receptor de Interleucina-3/inmunología , Leucemia Mieloide Aguda/tratamiento farmacológico , Terapia Molecular Dirigida/métodos , Selección de PacienteRESUMEN
We investigated CD25 expression in older (≥60 years) patients with new acute myelogenous leukemia treated with decitabine and plerixafor. Patients resistant to therapy or survival ≤1 year had significantly higher percentages of CD25pos myeloid blasts in baseline bone marrow. CD25pos patients had an increased odds of resistance compared to CD25neg patients (p = .015). In univariate analysis, we found CD25pos patients had inferior survival compared to CD25neg (p = .002). In patients with intermediate risk cytogenetics, CD25pos status stratified patients associating with inferior survival (p = .002). In multivariable analysis, CD25 and TP53 mutations trended towards predicting remission to therapy but were not predictive of survival. Only remission status, ASXL1 and TET2 mutations were found to independently predict overall survival (OS). We conclude CD25 expression identifies patients at risk for resistance to hypomethylating chemotherapy but does not independently predict OS in an older AML population treated with decitabine and plerixafor.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Decitabina/uso terapéutico , Compuestos Heterocíclicos/uso terapéutico , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Leucemia Mieloide Aguda/tratamiento farmacológico , Factores de Edad , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Bencilaminas , Médula Ósea/patología , Ciclamas , Metilación de ADN/efectos de los fármacos , Metilación de ADN/genética , Decitabina/farmacología , Resistencia a Antineoplásicos/genética , Femenino , Compuestos Heterocíclicos/farmacología , Humanos , Subunidad alfa del Receptor de Interleucina-2/genética , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Masculino , Persona de Mediana Edad , Mutación , Pronóstico , Inducción de Remisión/métodos , Estudios Retrospectivos , Análisis de Supervivencia , Resultado del Tratamiento , Proteína p53 Supresora de Tumor/genéticaRESUMEN
Pathogens have to balance transmission with persistence. For Plasmodium falciparum, the most widespread and virulent malaria parasite, persistence within its human host requires continuous asexual replication within red blood cells, while its mosquito-borne transmission depends on intra-erythrocytic differentiation into non-replicating sexual stages called gametocytes. Commitment to either fate is determined during the preceding cell cycle that begins with invasion by a single, asexually committed merozoite and ends, 48 hours later, with a schizont releasing newly formed merozoites, all committed to either continued asexual replication or differentiation into gametocytes. Sexual commitment requires the transcriptional activation of ap2-g (PF3D7_1222600), the master regulator of sexual development, from an epigenetically silenced state during asexual replication. AP2-G expression during this 'commitment cycle' prepares gene expression in nascent merozoites to initiate sexual development through a hitherto unknown mechanism. To maintain a persistent infection, the expression of ap2-g is limited to a sub-population of parasites (1-30%, depending on genetic background and growth conditions). As sexually committed schizonts comprise only a sub-population and are morphologically indistinguishable from their asexually committed counterparts, defining their characteristic gene expression has been difficult using traditional, bulk transcriptome profiling. Here we use highly parallel, single-cell RNA sequencing of malaria cultures undergoing sexual commitment to determine the transcriptional changes induced by AP2-G within this sub-population. By analysing more than 18,000 single parasite transcriptomes from a conditional AP2-G knockdown line and NF54 wild-type parasites at multiple stages of development, we show that sexually committed, AP2-G+ mature schizonts specifically upregulate additional regulators of gene expression, including other AP2 transcription factors, histone-modifying enzymes, and regulators of nucleosome positioning. These epigenetic regulators may act to facilitate the expression and/or repression of genes that are necessary for the initiation of gametocyte development in the subsequent cell cycle.
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Gametogénesis/genética , Malaria/parasitología , Plasmodium falciparum/citología , Plasmodium falciparum/genética , Análisis de Secuencia de ARN , Análisis de la Célula Individual , Transcriptoma/genética , Ciclo Celular , Femenino , Perfilación de la Expresión Génica , Histonas/metabolismo , Humanos , Masculino , Nucleosomas/genética , Nucleosomas/metabolismo , Plasmodium falciparum/crecimiento & desarrollo , Plasmodium falciparum/fisiología , Reproducción Asexuada , Esquizontes/citología , Esquizontes/genética , Factores de Transcripción/metabolismoRESUMEN
Chronic myelomonocytic leukemia is characterized by persistent absolute monocytosis (≥1 × 109/l) in the peripheral blood and dysplasia in ≥1 lineages. In the absence of dysplasia, an acquired clonal genetic abnormality is required or causes for reactive monocytosis have to be excluded. Oligomonocytic chronic myelomonocytic leukemia showing increased monocytes but no absolute monocytosis in the peripheral blood occurs occasionally. These cases are likely classified as myelodysplastic syndrome or myelodysplastic/myeloproliferative neoplasm, unclassifiable. A subset eventually develop overt chronic myelomonocytic leukemia. Better characterization of oligomonocytic chronic myelomonocytic leukemia is essential since the distinction between chronic myelomonocytic leukemia and myelodysplastic syndrome is clinically relevant. We identified 44 cases of oligomonocytic chronic myelomonocytic leukemia (≥10% peripheral blood monocytes with absolute monocyte count of 0.5-1 × 109/l) and 28 consecutive chronic myelomonocytic leukemia controls. Clinicopathologic features were compared and mutation analysis was performed. Oligomonocytic chronic myelomonocytic leukemia patients were significantly younger (median age of 65 vs 72). They had lower WBC and absolute neutrophil count, while the monocyte percentage, hemoglobin and platelet counts were similar in the two groups. The myeloid to erythroid ratio was predominantly decreased or normal, compared with the characteristic increase in chronic myelomonocytic leukemia (P=0.006). 38% of patients progressed to overt chronic myelomonocytic leukemia (median: 12 months). The overall percentage of mutations was significantly lower in oligomonocytic chronic myelomonocytic leukemia. However, the most frequent mutations in both groups were the 'signature' chronic myelomonocytic leukemia mutations in ASXL1, TET2 and SRSF2. Mutations in CBL were found exclusively in overt chronic myelomonocytic leukemia. In conclusion, we demonstrate clinical and genetic similarities between overt chronic myelomonocytic leukemia and oligomonocytic chronic myelomonocytic leukemia. The findings suggest that at least a subset of oligomonocytic chronic myelomonocytic leukemia represents early phase 'dysplastic type' chronic myelomonocytic leukemia.
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Biomarcadores de Tumor/genética , Leucemia Mielomonocítica Crónica/genética , Leucemia Mielomonocítica Crónica/patología , Monocitos/patología , Mutación , Adulto , Anciano , Anciano de 80 o más Años , Análisis Mutacional de ADN , Proteínas de Unión al ADN/genética , Diagnóstico Diferencial , Dioxigenasas , Femenino , Predisposición Genética a la Enfermedad , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Hibridación Fluorescente in Situ , Estimación de Kaplan-Meier , Leucemia Mielomonocítica Crónica/clasificación , Leucemia Mielomonocítica Crónica/terapia , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Fenotipo , Polimorfismo de Nucleótido Simple , Valor Predictivo de las Pruebas , Pronóstico , Proteínas Proto-Oncogénicas/genética , Proteínas Represoras/genética , Factores de Empalme Serina-Arginina/genética , Estados UnidosRESUMEN
The presence of minimal residual disease (MRD) is widely recognized as a powerful predictor of therapeutic outcome in acute myeloid leukemia (AML), but methods of measurement and quantification of MRD in AML are not yet standardized in clinical practice. There is an urgent, unmet need for robust and sensitive assays that can be readily adopted as real-time tools for disease monitoring. NPM1 frameshift mutations are an established MRD marker present in half of patients with cytogenetically normal AML. However, detection is complicated by the existence of hundreds of potential frameshift insertions, clonal heterogeneity, and absence of sequence information when the NPM1 mutation is identified using capillary electrophoresis. Thus, some patients are ineligible for NPM1 MRD monitoring. Furthermore, a subset of patients with NPM1-mutated AML will have false-negative MRD results because of clonal evolution. To simplify and improve MRD testing for NPM1, we present a novel digital PCR technique composed of massively multiplex pools of insertion-specific primers that selectively detect mutated but not wild-type NPM1. By measuring reaction end points using digital PCR technology, the resulting single assay enables sensitive and specific quantification of most NPM1 exon 12 mutations in a manner that is robust to clonal heterogeneity, does not require NPM1 sequence information, and obviates the need for maintenance of hundreds of type-specific assays and associated plasmid standards.
Asunto(s)
Leucemia Mieloide Aguda/genética , Reacción en Cadena de la Polimerasa Multiplex/métodos , Neoplasia Residual/genética , Proteínas Nucleares/genética , Línea Celular Tumoral , Células Cultivadas , Exones , Humanos , Leucemia Mieloide Aguda/diagnóstico , Mutación , Neoplasia Residual/diagnóstico , NucleofosminaRESUMEN
BACKGROUND: Although recombinant interferon-α (rIFNα) effectively treats patients with early myelofibrosis, the effect of driver and high molecular risk (HMR) mutations has not been considered. In this phase 2 study, for the first time, the authors correlate response to rIFNα treatment with driver and HMR mutations. METHODS: Patients were diagnosed using World Health Organization or International Working Group for Myeloproliferative Neoplasms Research and Treatment criteria. Only patients who had low or intermediate-1 Dynamic International Prognostic Scoring System scores with ≥15% hematopoietic bone marrow foci were included. History, symptom assessment, physical examination, and blood and bone marrow studies were performed. Genomic DNA was extracted from frozen cells, and next-generation targeted sequencing of 45 genes was performed. Either rIFNα-2b (0.5 million units subcutaneously 3 times weekly) or pegylated rIFNα-2a (45 µg weekly) with escalation was initiated. All patients were followed at the authors' institution, and regular bone marrow biopsies were encouraged. International Working Group for Myeloproliferative Neoplasms Research and Treatment and European LeukemiaNet treatment response criteria were used. RESULTS: Of 30 patients (16 women and 14 men; median age, 58 years), 22 were classified as low risk, and 8 were classified as intermediate-1 risk. Two patients achieved complete remission, 9 achieved partial remission, 4 had clinical improvement, 7 had stable disease; 3 had progressive disease, 1 relapsed, and 4 died. There were 22 patients with JAK mutations, 6 with CALR mutations, and 2 with MPL mutations. Seventy-three percent of patients improved or remained stable with acceptable toxicity, including 37% who achieved complete or partial remission. There was no correlation between treatment response and baseline driver mutations or Dynamic International Prognostic Scoring System scores. Of 8 poor responders, 3 had ASXL1 or SRSF2 mutations. CONCLUSIONS: Early treatment with rIFNα in patients without HMR mutations may prevent the development of marked splenomegaly, anemia, and florid myelofibrosis. Molecular profiling at the time of diagnosis may predict prognosis and treatment response. Cancer 2017;123:2680-87. © 2017 American Cancer Society.