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1.
Blood Adv ; 4(9): 2084-2094, 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32396620

RESUMO

We examined the risk of subsequent neoplasms (SNs) and late mortality in children and adolescents undergoing allogeneic hematopoietic cell transplantation (HCT) for nonmalignant diseases (NMDs). We included 6028 patients (median age, 6 years; interquartile range, 1-11; range, <1 to 20) from the Center for International Blood and Marrow Transplant Research (1995-2012) registry. Standardized mortality ratios (SMRs) in 2-year survivors and standardized incidence ratios (SIRs) were calculated to compare mortality and SN rates with expected rates in the general population. Median follow-up of survivors was 7.8 years. Diagnoses included severe aplastic anemia (SAA; 24%), Fanconi anemia (FA; 10%), other marrow failure (6%), hemoglobinopathy (15%), immunodeficiency (23%), and metabolic/leukodystrophy syndrome (22%). Ten-year survival was 93% (95% confidence interval [95% CI], 92% to 94%; SMR, 4.2; 95% CI, 3.7-4.8). Seventy-one patients developed SNs (1.2%). Incidence was highest in FA (5.5%), SAA (1.1%), and other marrow failure syndromes (1.7%); for other NMDs, incidence was <1%. Hematologic (27%), oropharyngeal (25%), and skin cancers (13%) were most common. Leukemia risk was highest in the first 5 years posttransplantation; oropharyngeal, skin, liver, and thyroid tumors primarily occurred after 5 years. Despite a low number of SNs, patients had an 11-fold increased SN risk (SIR, 11; 95% CI, 8.9-13.9) compared with the general population. We report excellent long-term survival and low SN incidence in an international cohort of children undergoing HCT for NMDs. The risk of SN development was highest in patients with FA and marrow failure syndromes, highlighting the need for long-term posttransplantation surveillance in this population.

2.
Biol Blood Marrow Transplant ; 26(2): 333-342, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31563573

RESUMO

Critically ill pediatric allogeneic hematopoietic cell transplant (HCT) patients may benefit from early and aggressive interventions aimed at reversing the progression of multiorgan dysfunction. Therefore, we evaluated 25 early risk factors for pediatric intensive care unit (PICU) mortality to improve mortality prognostication. We merged the Virtual Pediatric Systems and Center for International Blood and Marrow Transplant Research databases and analyzed 936 critically ill patients ≤21 years of age who had undergone allogeneic HCT and subsequently required PICU admission between January 1, 2009, and December 31, 2014. Of 1532 PICU admissions, the overall PICU mortality rate was 17.4% (95% confidence interval [CI], 15.6% to 19.4%) but was significantly higher for patients requiring mechanical ventilation (44.0%), renal replacement therapy (56.1%), or extracorporeal life support (77.8%). Mortality estimates increased significantly the longer that patients remained in the PICU. Of 25 HCT- and PICU-specific characteristics available at or near the time of PICU admission, moderate/severe pre-HCT renal injury, pre-HCT recipient cytomegalovirus seropositivity, <100-day interval between HCT and PICU admission, HCT for underlying acute myeloid leukemia, and greater admission organ dysfunction as approximated by the Pediatric Risk of Mortality 3 score were each independently associated with PICU mortality. A multivariable model using these components identified that patients in the top quartile of risk had 3 times greater mortality than other patients (35.1% versus 11.5%, P < .001, classification accuracy 75.2%; 95% CI, 73.0% to 77.4%). These data improve our working knowledge of the factors influencing the progression of critical illness in pediatric allogeneic HCT patients. Future investigation aimed at mitigating the effect of these risk factors is warranted.

4.
Blood Adv ; 3(7): 1118-1128, 2019 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-30952678

RESUMO

When hematopoietic stem cell transplant (HSCT) is necessary for children with acute myeloid leukemia (AML), there remains debate about the best stem cell source. Post-HSCT relapse is a common cause of mortality, and complications such as chronic graft versus host disease (cGVHD) are debilitating and life-threatening. To compare post-HSCT outcomes of different donor sources, we retrospectively analyzed consecutive transplants performed in several international centers from 2005 to 2015. A total of 317 patients were studied: 19% matched sibling donor (MSD), 23% matched unrelated donor (MUD), 39% umbilical cord blood (UCB), and 19% double UCB (dUCB) recipients. The median age at transplant was 10 years (range, 0.42-21 years), and median follow-up was 4.74 years (range, 4.02-5.39 years). Comparisons were made while controlling for patient, transplant, and disease characteristics. There were no differences in relapse, leukemia-free survival, or nonrelapse mortality. dUCB recipients had inferior survival compared with matched sibling recipients, but all other comparisons showed similar overall survival. Despite the majority of UCB transplants being HLA mismatched, the rates of cGVHD were low, especially compared with the well-matched MUD recipients (hazard ratio, 0.3; 95% confidence interval, 0.14-0.67; P = .02). The composite measure of cGVHD and leukemia-free survival (cGVHD-LFS), which represents both the quality of life and risk for mortality, was significantly better in the UCB compared with the MUD recipients (HR, 0.56; 95% confidence interval, 0.34-1; P = .03). In summary, the use of UCB is an excellent donor choice for pediatric patients with AML when a matched sibling cannot be identified.

5.
JAMA Pediatr ; 173(5): e190081, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30882883

RESUMO

Importance: Studies demonstrating improved survival after allogeneic hematopoietic cell transplant generally exclude infants. Objective: To analyze overall survival trends and other outcomes among infants who undergo allogeneic hematopoietic cell transplant. Design, Setting, and Participants: In this cohort study, we used time-trend analysis to evaluate 3 periods: 2000 through 2004, 2005 through 2009, and 2010 through 2014. The study was conducted in a multicenter setting through the Center for International Blood and Marrow Transplant Research, which is made up of a voluntary working group of more than 450 transplant centers worldwide. Two groups of infants aged 1 year or younger in 2 cohorts were included: those with malignant conditions, such as leukemia, and those with nonmalignant disorders, including immunodeficiencies. Data analysis was conducted from July 2017 to December 2018. Exposures: Allogeneic hematopoietic cell transplant. Main Outcomes and Measures: Survival trends, disease relapse, and toxicity. Results: A total of 2498 infants with a median age of 7 months (range, <1-12 months) were included. In the nonmalignant cohort (n = 472), survival rates improved from the first to the second period (hazard ratio, 0.77 [95% CI, 0.63-0.93]; P = .007) but did not change after 2004. Compared with infants with nonmalignant diseases (n = 2026; 3-year overall survival: 2000-2004, 375/577 [65.0%]; 2005-2009, 503/699 [72.0%]; and 2010-2014, 555/750 [74.0%]), those with malignant conditions had poorer survival rates, without improvement over time (3-year overall survival: 2000-2004, 109/199 [54.8%]; 2005-2009, 104/161 [64.6%]; and 2010-2014, 66/112 [58.9%]). From 2000 through 2014, relapse rates increased in infants with malignant conditions (3-year relapse rate: 2000-2004, 19% [95% CI, 14%-25%]; 2005-2009, 23% [95% CI, 17%-30%]; 2010-2014, 36% [95% CI, 27%-46%]; P = .01). Sinusoidal obstruction syndrome was frequent, occurring with a cumulative incidence of 13% (95% CI, 11%-16%) of infants with nonmalignant diseases and 32% (95% CI, 22%-42%) of those with malignant diseases. Generally, recipients of human leukocyte antigen-identical sibling bone marrow grafts had the best outcomes. Conclusions and Relevance: Survival rates have not improved for infants with malignant diseases over the 15-year study period. Infants with nonmalignant diseases had improved survival rates in the earlier but not the later study period. Higher relapses for the malignant cohort and toxicities for all infants remain significant challenges. Strategies to reduce relapse and toxicity and optimize donor and graft selection may improve outcomes in the future.


Assuntos
Transplante de Células-Tronco Hematopoéticas/mortalidade , Síndromes de Imunodeficiência/terapia , Leucemia/terapia , Causas de Morte/tendências , Estudos de Coortes , Feminino , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Hepatopatia Veno-Oclusiva/epidemiologia , Hepatopatia Veno-Oclusiva/etiologia , Humanos , Síndromes de Imunodeficiência/mortalidade , Incidência , Lactente , Recém-Nascido , Leucemia/mortalidade , Doenças Pulmonares Intersticiais/epidemiologia , Doenças Pulmonares Intersticiais/etiologia , Masculino , Mortalidade/tendências , Recidiva , Imunodeficiência Combinada Severa/mortalidade , Imunodeficiência Combinada Severa/terapia , Taxa de Sobrevida/tendências
6.
FASEB J ; 33(5): 6339-6353, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30768359

RESUMO

Classical cystathionine ß-synthase-deficient homocystinuria (HCU) is a life-threatening inborn error of sulfur metabolism. Treatment for pyridoxine-nonresponsive HCU involves lowering homocysteine (Hcy) with a methionine (Met)-restricted diet and betaine supplementation. Betaine treatment efficacy diminishes significantly over time due to impairment of betaine-Hcy S-methyltransferase (BHMT) function. Little is known regarding the regulation of BHMT in HCU. Using a betaine-responsive preclinical mouse model of HCU, we observed that this condition induces a 75% repression of BHMT mRNA, protein and enzyme activity, and significant depletion of hepatic betaine levels. BHMT repression was proportional to plasma Hcy levels but was not observed in mouse models of homocystinuria due to either methylenetetrahydrofolate reductase or Met synthase deficiency. Both Met supplementation and chemically induced glutathione depletion exacerbated hepatic BHMT repression in HCU mice but not wild-type (WT) controls. Conversely, cysteine treatment normalized hepatic BHMT expression in HCU mice but had no effect in WT control animals. Taurine treatment induced BHMT expression in HCU mice by 5-fold and restored maximal lowering of Hcy levels during long-term betaine treatment with a concomitant normalization of inflammatory cytokine expression and a significantly improved coagulative phenotype. Collectively, our findings indicate that adjuvantial taurine treatment has the potential to significantly improve clinical outcomes in HCU.-Maclean, K. N., Jiang, H, Phinney, W. N., Keating, A. K., Hurt, K. J., Stabler, S. P. Taurine alleviates repression of betaine-homocysteine S-methyltransferase and significantly improves the efficacy of long-term betaine treatment in a mouse model of cystathionine ß-synthase-deficient homocystinuria.

7.
Blood Adv ; 3(3): 350-359, 2019 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-30718242

RESUMO

Malglycemia (hypoglycemia, hyperglycemia, and/or glycemic variability) in adult hematopoietic stem cell transplant (HSCT) recipients is associated with increased infection, graft-versus-host disease, organ dysfunction, delayed engraftment, and mortality. Malglycemia has not been studied in pediatric HSCT recipients. This study aimed to characterize the incidence and consequences of malglycemia in this population. Medical records for a cohort of 344 patients, age 0 to 30 years, who underwent first HSCT from 2007 to 2016 at Children's Hospital Colorado were retrospectively reviewed. Glucose data were analyzed in intervals and assessed for potential risk factors and associated outcomes. Malglycemia occurred in 43.9% of patients. Patients with a day 0 to 100 mean glucose of 100 to 124 mg/dL had a 1.76-fold (95% confidence interval [CI], 1.10-2.82; P = .02) increased risk of death and patients with a day 0 to 100 mean glucose ≥ 125 mg/dL had a 7.06-fold (95% CI, 3.84-12.99; P < .0001) increased risk of death compared with patients with a day 0 to 100 mean glucose < 100 mg/dL. For each 10 mg/dL increase in pre-HSCT glucose, there was a 1.11-fold (95% CI, 1.04-1.18; P = .0013) increased risk of post-HSCT infection. These adverse impacts of malglycemia occurred independent of transplant type, graft-versus-host disease, and steroid therapy. Malglycemia in the pediatric HSCT population is independently associated with significantly increased risk of morbidity and mortality. Further research is required to evaluate the utility of glucose control to mitigate these relationships and improve HSCT outcomes. This trial was registered at www.clinicaltrials.gov as #NCT03482154.

8.
Bone Marrow Transplant ; 54(10): 1605-1613, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30783209

RESUMO

High-dose chemotherapy with autologous hematopoietic stem cell transplantation (autoHSCT) is a well-established treatment for pediatric central nervous system (CNS) tumors. Given the risks of toxicity and infection, pediatric autoHSCT has been historically performed on hospitalized children. As our practice evolved, some patients were transplanted as outpatients. We performed a retrospective cohort analysis of 37 patients who received 90 transplant procedures (49 outpatient and 41 inpatient) at Children's Hospital Colorado. The most common primary diagnosis was medulloblastoma (51.4%). Of the patients transplanted as outpatients, 69.4% were admitted for fever and neutropenia and had a median time to hospitalization of day +6, with fever and neutropenia being the most common reasons for admission. The median time to neutrophil engraftment was the same in both cohorts, 11 days. Median time to platelet engraftment was 13 days (8-82 days) vs 16 days (8-106 days) (p = 0.0008). At day +100, the transplant-related mortality (TRM) was 0% for both the cohorts. At a median follow-up of 1.7 years, overall survival (OS) for all patients was 66.1% and TRM was 0% for both the cohorts. Outpatient autoHSCT for properly selected children with CNS tumors is safe and effective.

9.
Biol Blood Marrow Transplant ; 23(8): 1342-1349, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28450183

RESUMO

This Center for International Blood and Marrow Transplant Research report describes the use of hematopoietic stem cell transplantation (HSCT) in pediatric patients with cancer, 4408 undergoing allogeneic (allo) and3076 undergoing autologous (auto) HSCT in the United States between 2008 and 2014. In both settings, there was a greater proportion of boys (n = 4327; 57%), children < 10 years of age (n = 4412; 59%), whites (n = 5787; 77%), and children with a performance score ≥ 90% at HSCT (n = 6187; 83%). Leukemia was the most common indication for an allo-transplant (n = 4170; 94%), and among these, acute lymphoblastic leukemia in second complete remission (n = 829; 20%) and acute myeloid leukemia in first complete remission (n = 800; 19%) werethe most common. The most frequently used donor relation, stem cell sources, and HLA match were unrelated donor (n = 2933; 67%), bone marrow (n = 2378; 54%), and matched at 8/8 HLA antigens (n = 1098; 37%) respectively. Most allo-transplants used myeloablative conditioning (n = 4070; 92%) and calcineurin inhibitors and methotrexate (n = 2245; 51%) for acute graft-versus-host disease prophylaxis. Neuroblastoma was the most common primary neoplasm for an auto-transplant (n = 1338; 44%). Tandem auto-transplants for neuroblastoma declined after 2012 (40% in 2011, 25% in 2012, and 8% in 2014), whereas tandem auto-transplants increased for brain tumors (57% in 2008 and 77% in 2014). Allo-transplants from relatives other than HLA-identical siblings doubled between 2008 and 2014 (3% in 2008 and 6% in 2014). These trends will be monitored in future reports of transplant practices in the United States.


Assuntos
Neoplasias Encefálicas/terapia , Inibidores de Calcineurina/administração & dosagem , Transplante de Células-Tronco Hematopoéticas , Metotrexato/administração & dosagem , Neuroblastoma/terapia , Condicionamento Pré-Transplante/métodos , Adolescente , Aloenxertos , Autoenxertos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos
10.
PLoS One ; 11(10): e0165107, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27783662

RESUMO

BACKGROUND: MER receptor tyrosine kinase (MERTK) is expressed in a variety of malignancies, including glioblastoma multiforme (GBM). Our previous work demonstrated that inhibition of MERTK using RNA interference induced cell death and chemosensitivity in GBM cells, implicating MERTK as a potential therapeutic target. Here we investigate whether a novel MERTK-selective small molecule tyrosine kinase inhibitor, UNC2025, has similar anti-tumor effects in GBM cell lines. METHODS: Correlations between expression of GAS6, a MERTK ligand, and prognosis were determined using data from the TCGA database. GBM cell lines (A172, SF188, U251) were treated in vitro with increasing doses of UNC2025 (50-400nM). Cell count and viability were determined by trypan blue exclusion. Cell cycle profiles and induction of apoptosis were assessed by flow cytometric analysis after BrdU or Po-Pro-1/propidium iodide staining, respectively. Polyploidy was detected by propidium iodide staining and metaphase spread. Cellular senescence was determined by ß-galactosidase staining and senescence-associated secretory cytokine analysis. RESULTS: Decreased overall survival significantly correlated with high levels of GAS6 expression in GBM, highlighting the importance of TAM kinase signaling in GBM tumorigenesis and/or therapy resistance and providing strong rationale for targeting these pathways in the clinic. All three GBM cell lines exhibited dose dependent reductions in cell number and colony formation (>90% at 200nM) after treatment with UNC2025. Cell cycle analysis demonstrated accumulation of cells in the G2/M phase and development of polyploidy. After extended exposure, 60-80% of cells underwent apoptosis. The majority of surviving cells (65-95%) were senescent and did not recover after drug removal. Thus, UNC2025 mediates anti-tumor activity in GBM by multiple mechanisms. CONCLUSIONS: The findings described here provide further evidence of oncogenic roles for MERTK in GBM, demonstrate the importance of kinase activity for MERTK tumorigenicity and validate UNC2025, a novel MERTK inhibitor, as a potential therapeutic agent for treatment of GBM.


Assuntos
Adenina/análogos & derivados , Morte Celular/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Glioblastoma/patologia , Piperazinas/farmacologia , Poliploidia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Adenina/farmacologia , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/patologia , Prognóstico , c-Mer Tirosina Quinase
11.
J Vis Exp ; (91): 52017, 2014 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-25285381

RESUMO

Orthotopic tumor models are currently the best way to study the characteristics of a tumor type, with and without intervention, in the context of a live animal - particularly in sites with unique physiological and architectural qualities such as the brain. In vitro and ectopic models cannot account for features such as vasculature, blood brain barrier, metabolism, drug delivery and toxicity, and a host of other relevant factors. Orthotopic models have their limitations too, but with proper technique tumor cells of interest can be accurately engrafted into tissue that most closely mimics conditions in the human brain. By employing methods that deliver precisely measured volumes to accurately defined locations at a consistent rate and pressure, mouse models of human brain tumors with predictable growth rates can be reproducibly created and are suitable for reliable analysis of various interventions. The protocol described here focuses on the technical details of designing and preparing for an intracranial injection, performing the surgery, and ensuring successful and reproducible tumor growth and provides starting points for a variety of conditions that can be customized for a range of different brain tumor models.


Assuntos
Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Transplante de Neoplasias/métodos , Transplante Heterólogo/métodos , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Masculino , Camundongos , Camundongos Nus
12.
Oncotarget ; 5(5): 1338-51, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24658326

RESUMO

Glioblastoma is an aggressive tumor that occurs in both adult and pediatric patients and is known for its invasive quality and high rate of recurrence. Current therapies for glioblastoma result in high morbidity and dismal outcomes. The TAM subfamily of receptor tyrosine kinases includes Tyro3, Axl, and MerTK. Axl and MerTK exhibit little to no expression in normal brain but are highly expressed in glioblastoma and contribute to the critical malignant phenotypes of survival, chemosensitivity and migration. We have found that Foretinib, a RTK inhibitor currently in clinical trial, inhibited phosphorylation of TAM receptors, with highest efficacy against MerTK, and blocked downstream activation of Akt and Erk in adult and pediatric glioblastoma cell lines, findings that are previously unreported. Survival, proliferation, migration, and collagen invasion were hindered in vitro. Foretinib treatment in vivo abolished MerTK phosphorylation and reduced tumor growth 3-4 fold in a subcutaneous mouse model. MerTK targeted shRNA completely prevented intracranial and subcutaneous glioma growth further delineating the impact of MerTK inhibition on glioblastoma. Our findings provide additional target validation for MerTK inhibition in glioblastoma and demonstrate that robust MerTK inhibition can be achieved with the multi-kinase inhibitor Foretinib as an innovative and translational therapeutic approach to glioblastoma.


Assuntos
Anilidas/farmacologia , Glioblastoma/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Quinolinas/farmacologia , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Anilidas/uso terapêutico , Animais , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glioblastoma/patologia , Humanos , Camundongos , Invasividade Neoplásica , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Quinolinas/uso terapêutico , RNA Interferente Pequeno/uso terapêutico , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , c-Mer Tirosina Quinase
13.
Brain Res ; 1542: 206-20, 2014 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-24184575

RESUMO

Receptor tyrosine kinases (RTKs) are cell surface proteins that tightly regulate a variety of downstream intra-cellular processes; ligand-receptor interactions result in cascades of signaling events leading to growth, proliferation, differentiation and migration. There are 58 described RTKs, which are further categorized into 20 different RTK families. When dysregulated or overexpressed, these RTKs are implicated in disordered growth, development, and oncogenesis. The TAM family of RTKs, consisting of Tyro3, Axl, and MerTK, is prominently expressed during the development and function of the central nervous system (CNS). Aberrant expression and dysregulated activation of TAM family members has been demonstrated in a variety of CNS-related disorders and diseases, including the most common but least treatable brain cancer in children and adults: glioblastoma multiforme.


Assuntos
Carcinogênese/genética , Sistema Nervoso Central/metabolismo , Proteínas Tirosina Quinases/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Animais , Humanos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Transdução de Sinais/fisiologia
14.
Blood ; 122(9): 1599-609, 2013 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-23861246

RESUMO

Acute lymphoblastic leukemia (ALL) is currently treated with an intense regimen of chemotherapy yielding cure rates near 85%. However, alterations to treatment strategies using available drugs are unlikely to provide significant improvement in survival or decrease therapy-associated toxicities. Here, we report ectopic expression of the Mer receptor tyrosine kinase in pre-B-cell ALL (B-ALL) cell lines and pediatric patient samples. Inhibition of Mer in B-ALL cell lines decreased activation of AKT and MAPKs and led to transcriptional changes, including decreased expression of antiapoptotic PRKCB gene and increase in proapoptotic BAX and BBC3 genes. Further, Mer inhibition promoted chemosensitization, decreased colony-forming potential in clonogenic assays, and delayed disease onset in a mouse xenograft model of leukemia. Our results identify Mer as a potential therapeutic target in B-ALL and suggest that inhibitors of Mer may potentiate lymphoblast killing when used in combination with chemotherapy. This strategy could reduce minimal residual disease and/or allow for chemotherapy dose reduction, thereby leading to improved event-free survival and reduced therapy-associated toxicity for patients with B-ALL. Additionally, Mer is aberrantly expressed in numerous other malignancies suggesting that this approach may have broad applications.


Assuntos
Terapia de Alvo Molecular , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Animais , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , RNA Interferente Pequeno/farmacologia , RNA Interferente Pequeno/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto , c-Mer Tirosina Quinase
15.
Pediatr Blood Cancer ; 60(4): 700-4, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22848000

RESUMO

BACKGROUND: Total body irradiation (TBI) is an important component of hematopoietic stem cell transplant (SCT) for pediatric malignancies. With increasing survival rates, late effects of SCT become more important. Younger children may be at particular risk of late effects of radiation and SCT. METHODS: We retrospectively reviewed outcomes of children less than 3 years of age who received TBI as part of their preparative regimen for SCT at Children's Hospital Colorado. Clinical information including the date of last follow-up, most recent lab values, and physiologic tests were extracted from the medical record. RESULTS: Of 81 patients who underwent SCT, 19 received TBI and of those, 15 were long-term survivors available for review. Late effects occurring in greater than 50% of the children included abnormalities involving endocrine, metabolic, renal, cataracts, and neurocognitive systems. Other organs involved less commonly included liver, skeletal, and cardiac abnormalities. Solid tumors were a rare finding with only one patient developing a benign osteochondroma and no identified secondary malignancies. CONCLUSIONS: TBI has been shown to be an important part of the preparative regimen for patients undergoing SCT. Our results, similar to other studies, suggest TBI in patients less than 3 years of age will likely result in multi-organ dysfunction including endocrine, metabolic, renal, eye, and neurocognitive abnormalities. A longitudinal study with standardized testing of these systems would further clarify the late effects concerns in this patient population.


Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Neoplasias/terapia , Sobreviventes , Irradiação Corporal Total/efeitos adversos , Pré-Escolar , Transtornos Cognitivos/epidemiologia , Transtornos Cognitivos/etiologia , Feminino , Humanos , Lactente , Masculino , Testes Neuropsicológicos , Estudos Retrospectivos , Resultado do Tratamento
16.
Mol Genet Metab ; 103(4): 330-7, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21601502

RESUMO

Cystathionine beta-synthase (CBS) deficient homocystinuria (HCU) is an inherited metabolic defect that if untreated, typically results in cognitive impairment, connective tissue disturbances, atherosclerosis and thromboembolic disease. In recent years, chronic inappropriate expression of the inflammatory response has emerged as a major driving force of both thrombosis and atherosclerotic lesion development. We report here a characterization of the abnormalities in cytokine expression induced in both a mouse model of HCU and human subjects with the disease in the presence and absence of homocysteine lowering therapy. HCU mice exhibited highly significant induction of the pro-inflammatory cytokines Il-1alpha, Il-1beta and TNF-alpha. Similarly, in untreated/poorly compliant human subjects with HCU we observed constitutive induction of multiple pro-inflammatory cytokines (IL-1alpha, IL-6, TNF-alpha, Il-17 and IL-12(p70)) and chemotactic chemokines (fractalkine, MIP-1alpha and MIP-1beta) compared to normal controls. These HCU patients also exhibited significant induction of IL-9, TGF-alpha and G-CSF. The expression levels of anti-inflammatory cytokines were unaffected in both HCU mice and human subjects with the disease. In the human subjects, homocysteine lowering therapy was associated with either normalization or significant reduction of all of the pro-inflammatory cytokines and chemokines investigated. We conclude that HCU is a disease of chronic inflammation and that aberrant cytokine expression has the potential to contribute to multiple aspects of pathogenesis. Our findings indicate that anti-inflammatory strategies could serve as a useful adjuvant therapy for this disease.


Assuntos
Quimiocinas/metabolismo , Cistationina beta-Sintase/genética , Homocistinúria/metabolismo , Adolescente , Adulto , Animais , Betaína/farmacologia , Quimiocina CCL4/metabolismo , Criança , Pré-Escolar , Cistationina beta-Sintase/deficiência , Cistationina beta-Sintase/metabolismo , Feminino , Homocistinúria/terapia , Humanos , Interleucina-17/metabolismo , Interleucina-1alfa/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Fator de Necrose Tumoral alfa/metabolismo
17.
Expert Opin Ther Targets ; 14(10): 1073-90, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20809868

RESUMO

IMPORTANCE OF THE FIELD: Axl and/or Mer expression correlates with poor prognosis in several cancers. Until recently, the role of these receptor tyrosine kinases (RTKs) in development and progression of cancer remained unexplained. Studies demonstrating that Axl and Mer contribute to cell survival, migration, invasion, metastasis and chemosensitivity justify further investigation of Axl and Mer as novel therapeutic targets in cancer. AREAS COVERED IN THIS REVIEW: Axl and Mer signaling pathways in cancer cells are summarized and evidence validating these RTKs as therapeutic targets in glioblastoma multiforme, NSCLC, and breast cancer is examined. A discussion of Axl and/or Mer inhibitors in development is provided. WHAT THE READER WILL GAIN: Potential toxicities associated with Axl or Mer inhibition are addressed. We propose that the probable action of Mer and Axl inhibitors on cells within the tumor microenvironment will provide a therapeutic opportunity to target both tumor cells and the stromal components that facilitate disease progression. TAKE HOME MESSAGE: Axl and Mer mediate multiple oncogenic phenotypes and activation of these RTKs constitutes a mechanism of chemoresistance in a variety of solid tumors. Targeted inhibition of these RTKs may be effective as anti-tumor and/or anti-metastatic therapy, particularly if combined with standard cytotoxic therapies.


Assuntos
Neoplasias/tratamento farmacológico , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios Clínicos como Assunto , Humanos , Neoplasias/genética , Proteínas Oncogênicas/genética , Proteínas Oncogênicas/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Resultado do Tratamento , Microambiente Tumoral
18.
Br J Haematol ; 151(4): 295-311, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20813012

RESUMO

Modifications to the treatment of acute lymphoblastic leukaemia (ALL) in children have led to a dramatic increase in survival in the past 40 years. Despite this success, a significant subset of paediatric leukaemia patients either relapse or fail to ever achieve a complete remission. Additionally, some patients necessitate treatment with intensified chemotherapy regimens due to clinical or laboratory findings which identify them as high risk. These patients are unlikely to respond to further minor adjustments to the dosing or timing of administration of the same chemotherapy medications. Many novel targeted therapies for the treatment of childhood ALL provide potential mechanisms to further improve cure rates, and provide the possibility of minimizing toxicity to non-malignant cells, given their specificity to malignant cell phenotypes. This article explores many of the potential targeted therapies in varying stages of development, from those currently in clinical trials to those still being refined in the research laboratory.


Assuntos
Antineoplásicos/uso terapêutico , Terapia de Alvo Molecular/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Criança , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Epigênese Genética/efeitos dos fármacos , Humanos , Fosfotransferases/antagonistas & inibidores , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia
19.
Mol Cancer Ther ; 9(5): 1298-307, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20423999

RESUMO

Astrocytomas account for the majority of malignant brain tumors diagnosed in both adult and pediatric patients. The therapies available to treat these neoplasms are limited, and the prognosis associated with high-grade lesions is extremely poor. Mer (MerTK) and Axl receptor tyrosine kinases (RTK) are expressed at abnormally high levels in a variety of malignancies, and these receptors are known to activate strong antiapoptotic signaling pathways that promote oncogenesis. In this study, we found that Mer and Axl mRNA transcript and protein expression were elevated in astrocytic patient samples and cell lines. shRNA-mediated knockdown of Mer and Axl RTK expression led to an increase in apoptosis in astrocytoma cells. Apoptotic signaling pathways including Akt and extracellular signal-regulated kinase 1/2, which have been shown to be activated in resistant astrocytomas, were downregulated with Mer and Axl inhibition whereas poly(ADP-ribose) polymerase cleavage was increased. Furthermore, Mer and Axl shRNA knockdown led to a profound decrease of astrocytoma cell proliferation in soft agar and a significant increase in chemosensitivity in response to temozolomide, carboplatin, and vincristine treatment. Our results suggest Mer and Axl RTK inhibition as a novel method to improve apoptotic response and chemosensitivity in astrocytoma and provide support for these oncogenes as attractive biological targets for astrocytoma drug development.


Assuntos
Apoptose/efeitos dos fármacos , Astrocitoma/patologia , Neoplasias Encefálicas/patologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteínas Proto-Oncogênicas/antagonistas & inibidores , RNA Interferente Pequeno/farmacologia , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Adulto , Apoptose/genética , Astrocitoma/tratamento farmacológico , Astrocitoma/genética , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Proliferação de Células/efeitos dos fármacos , Criança , Avaliação Pré-Clínica de Medicamentos , Resistencia a Medicamentos Antineoplásicos/genética , Técnicas de Silenciamento de Genes , Humanos , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas/genética , RNA Interferente Pequeno/administração & dosagem , Receptores Proteína Tirosina Quinases/genética , Células Tumorais Cultivadas , c-Mer Tirosina Quinase
20.
Pediatr Dev Pathol ; 13(3): 202-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20055684

RESUMO

Thymoma is an uncommon and slow-growing neoplasm. It is derived from thymic epithelial cells and comprises about 20% to 30% of mediastinal masses in adults, but only about 1% in pediatric patients. Patients usually present with mass-associated respiratory symptoms, superior vena cava syndrome, or paraneoplastic syndrome including myasthenia gravis, pure red cell aplasia, or acquired hypogammaglobulinemia, and connective tissue disorders. Due to the limited number of cases, knowledge, and experience with thymoma in pediatric patients, the diagnosis and treatment are very challenging for this age group. In this article, we report 2 cases of thymoma in childhood and provide a comprehensive review and analysis of the reported pediatric cases in the past 30 years (total of 32 cases). We found that patients younger than age 10 years were predominantly male (M:F = 6:1) and had advanced tumor stage more frequent than patients older than age 10 (P = .03). There were also significant associations of male sex with more advanced tumor stage and less favorable outcome (P = .03). These findings suggest that age and sex may be additional potential prognostic contributors in pediatric patients with thymoma. The clinicopathologic features, differential diagnosis, and current therapeutic recommendations of this uncommon tumor in pediatric patients are also addressed.


Assuntos
Timoma/patologia , Neoplasias do Timo/patologia , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimioterapia Adjuvante , Criança , Terapia Combinada , Feminino , Humanos , Masculino , Recidiva Local de Neoplasia/terapia , Radiografia , Indução de Remissão , Fatores Sexuais , Timectomia , Timoma/diagnóstico por imagem , Timoma/terapia , Neoplasias do Timo/diagnóstico por imagem , Neoplasias do Timo/terapia
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