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1.
Blood ; 2024 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-38643491

RESUMEN

Post-transplant lymphoproliferative disorder (PTLD) is a rare complication of solid organ transplantation, and cytotoxic chemotherapy is associated with treatment-related morbidity and mortality. Current treatment takes a sequential, risk-stratified approach, patients with low-risk disease following initial immunotherapy can avoid escalation to immunochemotherapy. TIDaL is a prospective, single-arm phase 2 trial investigating the activity and tolerability of ibrutinib combined with risk-stratified therapy for first-line treatment of PTLD. Eligible patients were adults with newly-diagnosed CD20-positive B-cell PTLD after solid organ transplant and performance status 0 to 2. Initial treatment comprised 49 days of ibrutinib 560mg once daily, with 4 doses of weekly rituximab. Treatment response on interim scan and baseline international prognostic index were used to allocate patients to either a low-risk arm (who continued ibrutinib, alongside 4 further doses of 3-weekly rituximab) or high-risk (escalation to R-CHOP immunochemotherapy, ibrutinib continuing in patients aged <65 years). The primary outcome was complete response on interim scan, achieved by 11/38 patients (29%, 95% confidence interval (CI) 15% - 46%). This did not reach the pre-specified threshold for clinically significant activity. Secondary outcomes included allocation to the low-risk arm (41% of patients), 2-year progression-free survival (58%, 95% CI 44% - 76%), and 2-year overall survival (76%, 95% CI 63% - 91%). Adverse events were mostly haematological, gastrointestinal and infective. Whilst TIDaL does not support adding ibrutinib into first-line treatment of PTLD, increasing the proportion of patients who can be treated without cytotoxic chemotherapy remains an important aim of future research. This trial was registered as ISRCTN32667607.

2.
Haematologica ; 109(2): 553-566, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-37646664

RESUMEN

Tafasitamab, an anti-CD19 immunotherapy, is used with lenalidomide for patients with autologous stem cell transplant-ineligible relapsed/refractory diffuse large B-cell lymphoma based on the results of the phase II L-MIND study (NCT02399085). We report the final 5-year analysis of this study. Eighty patients ≥18 years who had received one to three prior systemic therapies, and had Eastern Cooperative Oncology Group performance status 0-2 received up to 12 cycles of co-administered tafasitamab and lenalidomide, followed by tafasitamab monotherapy until disease progression or unacceptable toxicity. The primary endpoint was the best objective response rate. Secondary endpoints included duration of response, progression-free survival, overall survival, and safety. Exploratory analyses evaluated efficacy endpoints by prior lines of therapy. At data cutoff on November 14, 2022, the objective response rate was 57.5%, with a complete response rate of 41.3% (n=33), which was consistent with prior analyses. With a median follow-up of 44.0 months, the median duration of response was not reached. The median progression-free survival was 11.6 months (95% confidence interval [95% CI]: 5.7-45.7) with a median follow-up of 45.6 months. The median overall survival was 33.5 months (95% CI: 18.3-not reached) with a median follow-up of 65.6 months. Patients who had received one prior line of therapy (n=40) showed a higher objective response rate (67.5%; 52.5% complete responses) compared to patients who had received two or more prior lines of therapy (n=40; 47.5%; 30% complete responses), but the median duration of response was not reached in either subgroup. Other exploratory analyses revealed consistent long-term efficacy results across subgroups. Adverse events were consistent with those described in previous reports, were manageable, and their frequency decreased during tafasitamab monotherapy, with no new safety concerns. This final 5-year analysis of L-MIND demonstrates that the immunotherapy combination of tafasitamab and lenalidomide is well tolerated and has long-term clinical benefit with durable responses.


Asunto(s)
Linfoma de Células B Grandes Difuso , Linfoma no Hodgkin , Humanos , Lenalidomida/uso terapéutico , Linfoma no Hodgkin/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/patología , Anticuerpos Monoclonales Humanizados/uso terapéutico
4.
Value Health ; 27(1): 7-14, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37844662

RESUMEN

OBJECTIVES: Patients undergoing long-term anticancer therapy typically require one of 3 venous access devices: Hickman-type device (HICK), peripherally inserted central catheter (PICC), or implantable chest wall port (PORT). Recent evidence has shown PORT is safer and improves patient satisfaction. However, PORT did not show improvement in quality-adjusted life-years and was more expensive. Decisions regarding cost-effectiveness in the United Kingdom are typically informed by a cost-per-quality-adjusted life-year metric. However, this approach is limited in its ability to capture the full range of relevant outcomes, especially in the context of medical devices. This study assessed the potential cost-effectiveness of HICK, PICC, and PORT in routine clinical practice. METHODS: This is a cost-consequence analysis to determine the trade-offs between the following outcomes: complication, infection, noninfection, chemotherapy interruption, unplanned device removals, health utilities, device insertion cost, follow-up cost, and total cost, using data from the Cancer and Venous Access clinical trial. We conducted value of implementation analysis of a PORT service. RESULTS: PORT was superior in terms of overall complication rate compared with both HICK (incidence rate ratio 0.422; 95% CI 0.286-0.622) and PICC (incidence rate ratio 0.295; 95% CI 0.189-0.458) and less likely to lead to an unplanned device removal. There was no difference in chemotherapy interruption or health utilities. Total cost with device in situ was lower on PORT than HICK (-£98.86; 95% CI -189.20 to -8.53) and comparable with PICC -£48.57 (95% CI -164.99 to 67.86). Value of implementation analysis found that PORT was likely to be considered cost-effective within the National Health Service. CONCLUSION: Decision makers should consider including PORT within the suite of venous access devices available within in the National Health Service.


Asunto(s)
Cateterismo Venoso Central , Cateterismo Periférico , Neoplasias , Humanos , Cateterismo Venoso Central/efectos adversos , Análisis Costo-Beneficio , Medicina Estatal , Neoplasias/tratamiento farmacológico , Neoplasias/etiología , Cateterismo Periférico/efectos adversos
5.
Am J Hematol ; 98(5): 750-759, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36866925

RESUMEN

Bendamustine and rituximab (BR) therapy is commonly used in the treatment of Waldenström Macroglobulinemia (WM). The impact dose of Bendamustine dose on response and survival outcomes is not well-established, and the impact of its use in different treatment settings is not clear. We aimed to report response rates and survival outcomes following BR, and clarify the impact of depth of response and bendamustine dose on survival. A total of 250 WM patients treated with BR in the frontline or relapsed settings were included in this multicenter, retrospective cohort analysis. Rates of partial response (PR) or better differed significantly between the frontline and relapsed cohorts (91.4% vs 73.9%, respectively; p < 0.001). Depth of response impacted survival outcomes: two-year predicted PFS rates after achieving CR/VGPR vs PR were 96% versus 82%, respectively (p = 0.002). Total bendamustine dose was predictive of PFS: in the frontline setting, PFS was superior in the group receiving ≥1000 mg/m2 compared with those receiving 800-999 mg/m2 (p = 0.04). In the relapsed cohort, those who received doses of <600 mg/m2 had poorer PFS outcomes compared with those who received ≥600 mg/m2 (p = 0.02). Attaining CR/VGPR following BR results in superior survival, and total bendamustine dose significantly impacts response and survival outcomes, in both frontline and relapsed settings.


Asunto(s)
Macroglobulinemia de Waldenström , Humanos , Rituximab/uso terapéutico , Clorhidrato de Bendamustina/uso terapéutico , Macroglobulinemia de Waldenström/tratamiento farmacológico , Resultado del Tratamiento , Estudios Retrospectivos , Recurrencia Local de Neoplasia/tratamiento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica
6.
Palliat Med ; 37(2): 215-220, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36428287

RESUMEN

BACKGROUND: Chimeric Antigen-Receptor-T-cell (CAR-T) therapy is a potentially life-saving treatment for refractory haematological malignancies. Internationally, CAR-T services are undergoing rapid development. Despite this, research on the lived experiences of patients receiving novel immunotherapies is limited. Little is known about their supportive care needs. Consequently, dedicated palliative and supportive care services may not be considered. AIM: To explore the patient and caregiver experience of CAR-T therapy and identify unmet needs to inform service development. DESIGN: A qualitative longitudinal service evaluation. Sixteen interviews were conducted between December 2020 and March 2021 with patients (n = 10) and family caregivers (n = 4). Thematic analysis was underpinned by a constructivist approach. SETTING/PARTICIPANTS: All patients and caregivers attending one UK centre for CAR-T therapy were eligible. Semi-structured interviews were conducted at specific time points: prior to infusion, one month after infusion and follow-up post-treatment (5-18 months). RESULTS: Identified themes described the unique challenges of CAR-T therapy. From the point of referral patients had a wide range of supportive care needs. Initially, this was attributed to prior receipt of multiple failed treatments. Subsequently, CAR-T side-effects impacted on quality-of-life and physical function. Significant psychological morbidity from prognostic uncertainty was described throughout. Patients and caregivers reported that a dedicated nurse specialist - an expert, consistent point of contact - was essential. CONCLUSION: Patients and caregivers would benefit from early and ongoing support from palliative care, allied-health professionals and psychology. As indications for CAR-T therapy expand, there is an urgent need for multi-centre studies incorporating patient-reported outcome data to ensure patient-centred service delivery.


Asunto(s)
Neoplasias Hematológicas , Enfermería de Cuidados Paliativos al Final de la Vida , Receptores Quiméricos de Antígenos , Humanos , Cuidados Paliativos/psicología , Cuidadores/psicología , Investigación Cualitativa
7.
Br J Haematol ; 198(3): 492-502, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35485402

RESUMEN

CD19 CAR-T have emerged as a new standard treatment for relapsed/refractory (r/r) large B-cell lymphoma (LBCL). CAR-T real-world (RW) outcomes published to date suggest significant variability across countries. We provide results of a large national cohort of patients intended to be treated with CAR-T in the UK. Consecutive patients with r/r LBCL approved for CAR-T by the National CAR-T Clinical Panel between December 2018 and November 2020 across all UK CAR-T centres were included. 404/432 patients were approved [292 axicabtagene ciloleucel (axi-cel), 112 tisagenlecleucel (tisa-cel)], 300 (74%) received the cells. 110/300 (38.3%) patients achieved complete remission (CR) at 6 months (m). The overall response rate was 77% (52% CR) for axi-cel, 57% (44% CR) for tisa-cel. The 12-month progression-free survival was 41.8% (axi-cel) and 27.4% (tisa-cel). Median overall survival for the intention-to-treat population was 10.5 m, 16.2 m for infused patients. The incidence of grade ≥3 cytokine release syndrome and neurotoxicity were 7.6%/19.6% for axi-cel and 7.9%/3.9% for tisa-cel. This prospective RW population of CAR-T eligible patients offers important insights into the clinical benefit of CD19 CAR-T in LBCL in daily practice. Our results confirm long-term efficacy in patients receiving treatment similar to the pivotal trials, but highlight the significance of early CAR-T failure.


Asunto(s)
Inmunoterapia Adoptiva , Linfoma de Células B Grandes Difuso , Receptores Quiméricos de Antígenos , Antígenos CD19/uso terapéutico , Síndrome de Liberación de Citoquinas , Humanos , Inmunoterapia Adoptiva/métodos , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Estudios Prospectivos , Reino Unido/epidemiología
8.
Lancet ; 398(10298): 403-415, 2021 07 31.
Artículo en Inglés | MEDLINE | ID: mdl-34297997

RESUMEN

BACKGROUND: Hickman-type tunnelled catheters (Hickman), peripherally inserted central catheters (PICCs), and totally implanted ports (PORTs) are used to deliver systemic anticancer treatment (SACT) via a central vein. We aimed to compare complication rates and costs of the three devices to establish acceptability, clinical effectiveness, and cost-effectiveness of the devices for patients receiving SACT. METHODS: We did an open-label, multicentre, randomised controlled trial (Cancer and Venous Access [CAVA]) of three central venous access devices: PICCs versus Hickman (non-inferiority; 10% margin); PORTs versus Hickman (superiority; 15% margin); and PORTs versus PICCs (superiority; 15% margin). Adults (aged ≥18 years) receiving SACT (≥12 weeks) for solid or haematological malignancy from 18 oncology units in the UK were included. Four randomisation options were available: Hickman versus PICCs versus PORTs (2:2:1), PICCs versus Hickman (1:1), PORTs versus Hickman (1:1), and PORTs versus PICCs (1:1). Randomisation was done using a minimisation algorithm stratifying by centre, body-mass index, type of cancer, device history, and treatment mode. The primary outcome was complication rate (composite of infection, venous thrombosis, pulmonary embolus, inability to aspirate blood, mechanical failure, and other) assessed until device removal, withdrawal from study, or 1-year follow-up. This study is registered with ISRCTN, ISRCTN44504648. FINDINGS: Between Nov 8, 2013, and Feb 28, 2018, of 2714 individuals screened for eligibility, 1061 were enrolled and randomly assigned, contributing to the relevant comparison or comparisons (PICC vs Hickman n=424, 212 [50%] on PICC and 212 [50%] on Hickman; PORT vs Hickman n=556, 253 [46%] on PORT and 303 [54%] on Hickman; and PORT vs PICC n=346, 147 [42%] on PORT and 199 [58%] on PICC). Similar complication rates were observed for PICCs (110 [52%] of 212) and Hickman (103 [49%] of 212). Although the observed difference was less than 10%, non-inferiority of PICCs was not confirmed (odds ratio [OR] 1·15 [95% CI 0·78-1·71]) potentially due to inadequate power. PORTs were superior to Hickman with a complication rate of 29% (73 of 253) versus 43% (131 of 303; OR 0·54 [95% CI 0·37-0·77]). PORTs were superior to PICCs with a complication rate of 32% (47 of 147) versus 47% (93 of 199; OR 0·52 [0·33-0·83]). INTERPRETATION: For most patients receiving SACT, PORTs are more effective and safer than both Hickman and PICCs. Our findings suggest that most patients receiving SACT for solid tumours should receive a PORT within the UK National Health Service. FUNDING: UK National Institute for Health Research Health Technology Assessment Programme.


Asunto(s)
Antineoplásicos/administración & dosificación , Cateterismo Periférico , Catéteres de Permanencia , Catéteres Venosos Centrales , Neoplasias/tratamiento farmacológico , Dispositivos de Acceso Vascular , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/uso terapéutico , Infecciones Relacionadas con Catéteres/etiología , Cateterismo Periférico/efectos adversos , Catéteres de Permanencia/efectos adversos , Catéteres de Permanencia/economía , Catéteres Venosos Centrales/efectos adversos , Catéteres Venosos Centrales/economía , Análisis Costo-Beneficio , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dispositivos de Acceso Vascular/economía , Adulto Joven
9.
Haematologica ; 107(9): 2051-2063, 2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-34788984

RESUMEN

Despite being predominantly a childhood disease, the incidence of acute lymphoblastic leukemia (ALL) has a second peak in adults aged 60 years and over. These older adults fare extremely poorly with existing treatment strategies and very few studies have undertaken a comprehensive genetic and genomic characterization to improve prognosis in this age group. We performed cytogenetic, single nucleotide polymorphism (SNP) array and next-generation sequencing (NGS) analyses on samples from 210 patients aged ≥60 years from the UKALL14 and UKALL60+ clinical trials. BCR-ABL1-positive disease was present in 26% (55/210) of patients, followed by low hypodiploidy/near triploidy in 13% (28/210). Cytogenetically cryptic rearrangements in CRLF2, ZNF384 and MEF2D were detected in 5%, 1% and <1% of patients, respectively. Copy number abnormalities were common and deletions in ALL driver genes were seen in 77% of cases. IKZF1 deletion was present in 51% (40/78) of samples tested and the IKZF1plus profile was identified in over a third (28/77) of cases of B-cell precursor ALL. The genetic good-risk abnormalities high hyperdiploidy (n=2), ETV6-RUNX1 (no cases) and ERG deletion (no cases) were exceptionally rare in this cohort. RAS pathway mutations were seen in 17% (4/23) of screened samples. KDM6A abnormalities, including biallelic deletions, were discovered in 5% (4/78) of SNP arrays and 9% (2/23) of NGS samples, and represent novel, potentially therapeutically actionable lesions using EZH2 inhibitors. Outcome remained poor with 5-year event-free and overall survival rates of 17% and 24%, respectively, across the cohort, indicating a need for novel therapeutic strategies.


Asunto(s)
Leucemia-Linfoma Linfoblástico de Células Precursoras B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Anciano , Niño , Estudios de Cohortes , Reordenamiento Génico , Genómica , Humanos , Persona de Mediana Edad , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Pronóstico
10.
Br J Haematol ; 193(1): 63-71, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-32926420

RESUMEN

Standard treatment for classical Hodgkin lymphoma (cHL) is poorly tolerated in older patients and results disappointing. We assessed safety and efficacy of brentuximab vedotin (BV), in previously untreated patients with cHL unfit for standard treatment due to age, frailty or comorbidity. The primary outcome was complete metabolic response (CMR) by positron emission tomography/computed tomography after four BV cycles (PET4). The secondary outcomes included progression-free survival (PFS), overall survival (OS), and toxicity. In all, 35 patients with a median age of 77 years and median total Cumulative Illness Rating Scale for Geriatrics (CIRS-G) score of 6 were evaluable for toxicity and 31 for response. A median of four cycles were given (range one-16). In all, 14 patients required dose reduction due to toxicity and 11 patients stopped treatment due to adverse events (AEs). A total of 716 AEs were reported, of which 626 (88%) were Grade 1/2 and 27 (77%) patients had at least one AE Grade ≥3. At PET4, CMR was 25·8% [95% confidence interval (CI) 13·7-42.2%] and objective response rate 83·9% (95% CI 63·7-90·8%). Median PFS was 7·3 months (95% CI 5·2-9·0), and OS 19·5 months. Our results suggest that BV monotherapy is tolerable but suboptimal in the front-line therapy of elderly or comorbid patients with cHL. Combining BV with other agents may be more effective. Trial Registration: Clinicaltrials.gov identifier: NCT02567851.


Asunto(s)
Antineoplásicos Inmunológicos/uso terapéutico , Brentuximab Vedotina/uso terapéutico , Quimioterapia/normas , Fragilidad/epidemiología , Enfermedad de Hodgkin/tratamiento farmacológico , Factores de Edad , Anciano , Anciano de 80 o más Años , Antineoplásicos Inmunológicos/administración & dosificación , Antineoplásicos Inmunológicos/efectos adversos , Antineoplásicos Inmunológicos/toxicidad , Biomarcadores de Tumor/metabolismo , Brentuximab Vedotina/administración & dosificación , Brentuximab Vedotina/efectos adversos , Brentuximab Vedotina/toxicidad , Comorbilidad , Relación Dosis-Respuesta a Droga , Quimioterapia/ética , Femenino , Enfermedad de Hodgkin/metabolismo , Enfermedad de Hodgkin/patología , Humanos , Masculino , Estadificación de Neoplasias/métodos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Supervivencia sin Progresión , Seguridad , Resultado del Tratamiento , Reino Unido/epidemiología
12.
Haematologica ; 106(9): 2417-2426, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-34196165

RESUMEN

Tafasitamab (MOR208), an Fc-modified, humanized, anti-CD19 monoclonal antibody, combined with the immunomodulatory drug lenalidomide was clinically active with a good tolerability profile in the open-label, single-arm, phase II L-MIND study of patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) ineligible for autologous stem-cell transplantation. To assess long-term outcomes, we report an updated analysis with ≥35 months' follow-up. Patients were aged >18 years, had received one to three prior systemic therapies (including ≥1 CD20-targeting regimen) and Eastern Cooperative Oncology Group performance status 0-2. Patients received 28-day cycles of tafasitamab (12 mg/kg intravenously), once weekly during cycles 1-3, then every 2 weeks during cycles 4-12. Lenalidomide (25 mg orally) was administered on days 1-21 of cycles 1-12. After cycle 12, progression-free patients received tafasitamab every 2 weeks until disease progression. The primary endpoint was best objective response rate. After ≥35 months' follow-up (data cut-off: October 30, 2020), the objective response rate was 57.5% (n=46/80), including a complete response in 40.0% of patients (n=32/80) and a partial response in 17.5% of patients (n=14/80). The median duration of response was 43.9 months (95% confidence interval [95% CI]: 26.1-not reached), the median overall survival was 33.5 months (95% CI: 18.3-not reached) and the median progression-free survival was 11.6 months (95% CI: 6.3-45.7). There were no unexpected toxicities. Subgroup analyses revealed consistent long-term efficacy results across most subgroups of patients. This extended follow-up of L-MIND confirms the long duration of response, meaningful overall survival, and well-defined safety profile of tafasitamab plus lenalidomide followed by tafasitamab monotherapy in patients with relapsed/refractory diffuse large B-cell lymphoma ineligible for autologous stem cell transplantation. ClinicalTrials.gov identifier: NCT02399085.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Linfoma de Células B Grandes Difuso , Anticuerpos Monoclonales Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Humanos , Lenalidomida/uso terapéutico , Linfoma de Células B Grandes Difuso/diagnóstico , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Trasplante Autólogo , Resultado del Tratamiento
15.
Genes Dev ; 25(9): 917-29, 2011 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-21536732

RESUMEN

Removal of the assembly factor eukaryotic initiation factor 6 (eIF6) is critical for late cytoplasmic maturation of 60S ribosomal subunits. In mammalian cells, the current model posits that eIF6 release is triggered following phosphorylation of Ser 235 by activated protein kinase C. In contrast, genetic studies in yeast indicate a requirement for the ortholog of the SBDS (Shwachman-Bodian-Diamond syndrome) gene that is mutated in the inherited leukemia predisposition disorder Shwachman-Diamond syndrome (SDS). Here, by isolating late cytoplasmic 60S ribosomal subunits from Sbds-deleted mice, we show that SBDS and the GTPase elongation factor-like 1 (EFL1) directly catalyze eIF6 removal in mammalian cells by a mechanism that requires GTP binding and hydrolysis by EFL1 but not phosphorylation of eIF6 Ser 235. Functional analysis of disease-associated missense variants reveals that the essential role of SBDS is to tightly couple GTP hydrolysis by EFL1 on the ribosome to eIF6 release. Furthermore, complementary NMR spectroscopic studies suggest unanticipated mechanistic parallels between this late step in 60S maturation and aspects of bacterial ribosome disassembly. Our findings establish a direct role for SBDS and EFL1 in catalyzing the translational activation of ribosomes in all eukaryotes, and define SDS as a ribosomopathy caused by uncoupling GTP hydrolysis from eIF6 release.


Asunto(s)
Factores Eucarióticos de Iniciación/metabolismo , Guanosina Trifosfato/metabolismo , Ribosomas/patología , Animales , Enfermedades de la Médula Ósea/genética , Enfermedades de la Médula Ósea/fisiopatología , Catálisis , Células Cultivadas , Modelos Animales de Enfermedad , Factores Eucarióticos de Iniciación/genética , Insuficiencia Pancreática Exocrina/genética , Insuficiencia Pancreática Exocrina/fisiopatología , Humanos , Hidrólisis , Lipomatosis , Hígado/patología , Ratones , Ratones Endogámicos C57BL , Modelos Moleculares , Mutación , Factores de Iniciación de Péptidos/genética , Factores de Iniciación de Péptidos/metabolismo , Fosforilación , Unión Proteica , Estructura Terciaria de Proteína , Proteínas/química , Proteínas/genética , Proteínas/metabolismo , Subunidades Ribosómicas Grandes de Eucariotas , Síndrome de Shwachman-Diamond
16.
Genes Dev ; 24(8): 783-98, 2010 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-20395365

RESUMEN

The developmental switch from human fetal (gamma) to adult (beta) hemoglobin represents a clinically important example of developmental gene regulation. The transcription factor BCL11A is a central mediator of gamma-globin silencing and hemoglobin switching. Here we determine chromatin occupancy of BCL11A at the human beta-globin locus and other genomic regions in vivo by high-resolution chromatin immunoprecipitation (ChIP)-chip analysis. BCL11A binds the upstream locus control region (LCR), epsilon-globin, and the intergenic regions between gamma-globin and delta-globin genes. A chromosome conformation capture (3C) assay shows that BCL11A reconfigures the beta-globin cluster by modulating chromosomal loop formation. We also show that BCL11A and the HMG-box-containing transcription factor SOX6 interact physically and functionally during erythroid maturation. BCL11A and SOX6 co-occupy the human beta-globin cluster along with GATA1, and cooperate in silencing gamma-globin transcription in adult human erythroid progenitors. These findings collectively demonstrate that transcriptional silencing of gamma-globin genes by BCL11A involves long-range interactions and cooperation with SOX6. Our findings provide insight into the mechanism of BCL11A action and new clues for the developmental gene regulatory programs that function at the beta-globin locus.


Asunto(s)
Proteínas Portadoras/metabolismo , Células Eritroides/metabolismo , Regulación del Desarrollo de la Expresión Génica , Silenciador del Gen , Proteínas Nucleares/metabolismo , Factores de Transcripción SOXD/metabolismo , gamma-Globinas/metabolismo , Adulto , Animales , Línea Celular , Células Eritroides/citología , Eritropoyesis/fisiología , Factor de Transcripción GATA1/metabolismo , Histonas/metabolismo , Humanos , Ratones , Unión Proteica , Transporte de Proteínas , Proteínas Represoras
18.
Nat Genet ; 39(4): 486-95, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17353896

RESUMEN

The autosomal recessive disorder Shwachman-Diamond syndrome, characterized by bone marrow failure and leukemia predisposition, is caused by deficiency of the highly conserved Shwachman-Bodian-Diamond syndrome (SBDS) protein. Here, we identify the function of the yeast SBDS ortholog Sdo1, showing that it is critical for the release and recycling of the nucleolar shuttling factor Tif6 from pre-60S ribosomes, a key step in 60S maturation and translational activation of ribosomes. Using genome-wide synthetic genetic array mapping, we identified multiple TIF6 gain-of-function alleles that suppressed the pre-60S nuclear export defects and cytoplasmic mislocalization of Tif6 observed in sdo1Delta cells. Sdo1 appears to function within a pathway containing elongation factor-like 1, and together they control translational activation of ribosomes. Thus, our data link defective late 60S ribosomal subunit maturation to an inherited bone marrow failure syndrome associated with leukemia predisposition.


Asunto(s)
Biosíntesis de Proteínas/genética , Ribosomas/metabolismo , Proteínas de Saccharomyces cerevisiae/fisiología , Saccharomyces cerevisiae/genética , Proteínas Portadoras/genética , GTP Fosfohidrolasas/genética , GTP Fosfohidrolasas/fisiología , Eliminación de Gen , Proteínas de Filamentos Intermediarios/genética , Modelos Biológicos , Modelos Moleculares , Mutación , Organismos Modificados Genéticamente , Factores de Elongación de Péptidos/genética , Factores de Elongación de Péptidos/fisiología , Fosfoproteínas/genética , Biosíntesis de Proteínas/efectos de los fármacos , Inhibidores de la Síntesis de la Proteína/farmacología , Proteínas Ribosómicas , Saccharomyces cerevisiae/crecimiento & desarrollo , Proteínas de Saccharomyces cerevisiae/genética
19.
Proc Natl Acad Sci U S A ; 109(43): 17567-72, 2012 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-23045682

RESUMEN

Trisomy 21 is associated with hematopoietic abnormalities in the fetal liver, a preleukemic condition termed transient myeloproliferative disorder, and increased incidence of acute megakaryoblastic leukemia. Human trisomy 21 pluripotent cells of various origins, human embryonic stem (hES), and induced pluripotent stem (iPS) cells, were differentiated in vitro as a model to recapitulate the effects of trisomy on hematopoiesis. To mitigate clonal variation, we isolated disomic and trisomic subclones from the same parental iPS line, thereby generating subclones isogenic except for chromosome 21. Under differentiation conditions favoring development of fetal liver-like, γ-globin expressing, definitive hematopoiesis, we found that trisomic cells of hES, iPS, or isogenic origins exhibited a two- to fivefold increase in a population of CD43(+)(Leukosialin)/CD235(+)(Glycophorin A) hematopoietic cells, accompanied by increased multilineage colony-forming potential in colony-forming assays. These findings establish an intrinsic disturbance of multilineage myeloid hematopoiesis in trisomy 21 at the fetal liver stage.


Asunto(s)
Diferenciación Celular , Síndrome de Down , Hematopoyesis , Células Madre Pluripotentes/citología , Perfilación de la Expresión Génica , Humanos , Cariotipificación , Reacción en Cadena de la Polimerasa
20.
Proc Natl Acad Sci U S A ; 108(4): 1519-24, 2011 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-21205891

RESUMEN

Many human aneuploidy syndromes have unique phenotypic consequences, but in most instances it is unclear whether these phenotypes are attributable to alterations in the dosage of specific genes. In human trisomy 13, there is delayed switching and persistence of fetal hemoglobin (HbF) and elevation of embryonic hemoglobin in newborns. Using partial trisomy cases, we mapped this trait to chromosomal band 13q14; by examining the genes in this region, two microRNAs, miR-15a and -16-1, appear as top candidates for the elevated HbF levels. Indeed, increased expression of these microRNAs in primary human erythroid progenitor cells results in elevated fetal and embryonic hemoglobin gene expression. Moreover, we show that a direct target of these microRNAs, MYB, plays an important role in silencing the fetal and embryonic hemoglobin genes. Thus we demonstrate how the developmental regulation of a clinically important human trait can be better understood through the genetic and functional study of aneuploidy syndromes and suggest that miR-15a, -16-1, and MYB may be important therapeutic targets to increase HbF levels in patients with sickle cell disease and ß-thalassemia.


Asunto(s)
Cromosomas Humanos Par 13/genética , Hemoglobina Fetal/genética , MicroARNs/genética , Proteínas Proto-Oncogénicas c-myb/genética , Trisomía , Algoritmos , Antígenos CD/metabolismo , Secuencia de Bases , Western Blotting , Células Precursoras Eritroides/metabolismo , Femenino , Hemoglobina Fetal/metabolismo , Perfilación de la Expresión Génica , Células HEK293 , Humanos , Lactante , Recién Nacido , Células K562 , Masculino , Modelos Genéticos , Datos de Secuencia Molecular , Análisis de Secuencia por Matrices de Oligonucleótidos , Receptores de Transferrina/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
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