Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Blood ; 135(4): 274-286, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31738823

RESUMO

Pediatric large B-cell lymphomas (LBCLs) share morphological and phenotypic features with adult types but have better prognosis. The higher frequency of some subtypes such as LBCL with IRF4 rearrangement (LBCL-IRF4) in children suggests that some age-related biological differences may exist. To characterize the genetic and molecular heterogeneity of these tumors, we studied 31 diffuse LBCLs (DLBCLs), not otherwise specified (NOS); 20 LBCL-IRF4 cases; and 12 cases of high-grade B-cell lymphoma (HGBCL), NOS in patients ≤25 years using an integrated approach, including targeted gene sequencing, copy-number arrays, and gene expression profiling. Each subgroup displayed different molecular profiles. LBCL-IRF4 had frequent mutations in IRF4 and NF-κB pathway genes (CARD11, CD79B, and MYD88), losses of 17p13 and gains of chromosome 7, 11q12.3-q25, whereas DLBCL, NOS was predominantly of germinal center B-cell (GCB) subtype and carried gene mutations similar to the adult counterpart (eg, SOCS1 and KMT2D), gains of 2p16/REL, and losses of 19p13/CD70. A subset of HGBCL, NOS displayed recurrent alterations of Burkitt lymphoma-related genes such as MYC, ID3, and DDX3X and homozygous deletions of 9p21/CDKN2A, whereas other cases were genetically closer to GCB DLBCL. Factors related to unfavorable outcome were age >18 years; activated B-cell (ABC) DLBCL profile, HGBCL, NOS, high genetic complexity, 1q21-q44 gains, 2p16/REL gains/amplifications, 19p13/CD70 homozygous deletions, and TP53 and MYC mutations. In conclusion, these findings further unravel the molecular heterogeneity of pediatric and young adult LBCL, improve the classification of this group of tumors, and provide new parameters for risk stratification.

2.
Neurol Neuroimmunol Neuroinflamm ; 6(2): e538, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30800721

RESUMO

Objective: To report 2 patients with anti-myelin oligodendrocyte glycoprotein (MOG)-associated encephalitis who were initially misdiagnosed with small vessel primary CNS vasculitis. Methods: Review of symptoms, MRI and neuropathologic features, and response to treatment. MOG antibodies were determined in serum and CSF using a cell-based assay. Results: Symptoms included fever, headache, and progressive mental status changes and focal neurologic deficits. CSF studies revealed lymphocytic pleocytosis, and both patients had abnormal brain MRIs. Brain biopsy samples showed prominent lymphocytic infiltration of the wall of small vessels; these findings initially suggested small vessel CNS vasculitis, and both patients were treated accordingly. Although 1 patient had a relapsing-remitting course not responsive to cyclophosphamide, the other one (also treated with cyclophosphamide) did not relapse. Retrospective assessment of serum and CSF demonstrated MOG antibodies in both cases, and review of biopsy specimens showed absence of fibrinoid necrosis (a pathologic requirement for small vessel CNS vasculitis). Conclusions: Anti-MOG-associated encephalitis can be mistaken for small vessel CNS vasculitis. This is important because the diagnosis of anti-MOG-associated encephalitis does not require brain biopsy and can be established with a serologic test.

3.
Sci Transl Med ; 11(476)2019 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-30674657

RESUMO

Retinoblastoma is a pediatric solid tumor of the retina activated upon homozygous inactivation of the tumor suppressor RB1 VCN-01 is an oncolytic adenovirus designed to replicate selectively in tumor cells with high abundance of free E2F-1, a consequence of a dysfunctional RB1 pathway. Thus, we reasoned that VCN-01 could provide targeted therapeutic activity against even chemoresistant retinoblastoma. In vitro, VCN-01 effectively killed patient-derived retinoblastoma models. In mice, intravitreous administration of VCN-01 in retinoblastoma xenografts induced tumor necrosis, improved ocular survival compared with standard-of-care chemotherapy, and prevented micrometastatic dissemination into the brain. In juvenile immunocompetent rabbits, VCN-01 did not replicate in retinas, induced minor local side effects, and only leaked slightly and for a short time into the blood. Initial phase 1 data in patients showed the feasibility of the administration of intravitreous VCN-01 and resulted in antitumor activity in retinoblastoma vitreous seeds and evidence of viral replication markers in tumor cells. The treatment caused local vitreous inflammation but no systemic complications. Thus, oncolytic adenoviruses targeting RB1 might provide a tumor-selective and chemotherapy-independent treatment option for retinoblastoma.

4.
Nat Med ; 25(1): 176-187, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30531922

RESUMO

Neurofibromatosis type 1 (NF1) is a common tumor predisposition syndrome in which glioma is one of the prevalent tumors. Gliomagenesis in NF1 results in a heterogeneous spectrum of low- to high-grade neoplasms occurring during the entire lifespan of patients. The pattern of genetic and epigenetic alterations of glioma that develops in NF1 patients and the similarities with sporadic glioma remain unknown. Here, we present the molecular landscape of low- and high-grade gliomas in patients affected by NF1 (NF1-glioma). We found that the predisposing germline mutation of the NF1 gene was frequently converted to homozygosity and the somatic mutational load of NF1-glioma was influenced by age and grade. High-grade tumors harbored genetic alterations of TP53 and CDKN2A, frequent mutations of ATRX associated with Alternative Lengthening of Telomere, and were enriched in genetic alterations of transcription/chromatin regulation and PI3 kinase pathways. Low-grade tumors exhibited fewer mutations that were over-represented in genes of the MAP kinase pathway. Approximately 50% of low-grade NF1-gliomas displayed an immune signature, T lymphocyte infiltrates, and increased neo-antigen load. DNA methylation assigned NF1-glioma to LGm6, a poorly defined Isocitrate Dehydrogenase 1 wild-type subgroup enriched with ATRX mutations. Thus, the profiling of NF1-glioma defined a distinct landscape that recapitulates a subset of sporadic tumors.


Assuntos
Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/genética , Glioma/complicações , Glioma/genética , Neurofibromatose 1/complicações , Neurofibromatose 1/genética , Adolescente , Adulto , Antígenos de Neoplasias/metabolismo , Neoplasias Encefálicas/imunologia , Criança , Pré-Escolar , Estudos de Coortes , Metilação de DNA/genética , Feminino , Mutação em Linhagem Germinativa/genética , Glioma/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Neurofibromina 1/genética , Reprodutibilidade dos Testes , Linfócitos T/imunologia , Transcriptoma/genética , Proteína Nuclear Ligada ao X/genética , Adulto Jovem
5.
Nat Med ; 24(8): 1204-1215, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29967352

RESUMO

The failure to develop effective therapies for pediatric glioblastoma (pGBM) and diffuse intrinsic pontine glioma (DIPG) is in part due to their intrinsic heterogeneity. We aimed to quantitatively assess the extent to which this was present in these tumors through subclonal genomic analyses and to determine whether distinct tumor subpopulations may interact to promote tumorigenesis by generating subclonal patient-derived models in vitro and in vivo. Analysis of 142 sequenced tumors revealed multiple tumor subclones, spatially and temporally coexisting in a stable manner as observed by multiple sampling strategies. We isolated genotypically and phenotypically distinct subpopulations that we propose cooperate to enhance tumorigenicity and resistance to therapy. Inactivating mutations in the H4K20 histone methyltransferase KMT5B (SUV420H1), present in <1% of cells, abrogate DNA repair and confer increased invasion and migration on neighboring cells, in vitro and in vivo, through chemokine signaling and modulation of integrins. These data indicate that even rare tumor subpopulations may exert profound effects on tumorigenesis as a whole and may represent a new avenue for therapeutic development. Unraveling the mechanisms of subclonal diversity and communication in pGBM and DIPG will be an important step toward overcoming barriers to effective treatments.


Assuntos
Neoplasias do Tronco Encefálico/patologia , Glioblastoma/patologia , Animais , Neoplasias do Tronco Encefálico/genética , Carcinogênese/patologia , Separação Celular , Criança , Células Clonais , Genótipo , Glioblastoma/genética , Humanos , Camundongos Nus , Fenótipo , Células Tumorais Cultivadas
6.
Adv Healthc Mater ; 7(15): e1800255, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29892999

RESUMO

Delivery of chemotherapy in the surgical bed has shown preclinical activity to control cancer progression upon subtotal resection of pediatric solid tumors, but whether this new treatment is safe for tumor-adjacent healthy tissues remains unknown. Here, Wistar rats are used to study the anatomic and functional impact of electrospun nanofiber matrices eluting SN-38-a potent chemotherapeutic agent-on several body sites where pediatric tumors such as neuroblastoma, Ewing sarcoma, and rhabdomyosarcoma arise. Blank and SN-38-loaded matrices embracing the femoral neurovascular bundle or in direct contact with abdominal viscera (liver, kidney, urinary bladder, intestine, and uterus) are placed. Foreign body tissue reaction to the implants is observed though no histologic damage in any tissue/organ. Skin healing is normal. Tissue reaction is similar for SN-38-loaded and blank matrices, with the exception of the hepatic capsule that is thicker for the former although within the limits consistent with mild foreign body reaction. Tissue and organ function is completely conserved after local treatments, as assessed by the rotarod test (forelimb function), hematologic tests (liver and renal function), and control of clinical signs. Overall, these findings support the clinical translation of SN-38-loaded nanofiber matrices to improve local control strategies of surgically resected tumors.


Assuntos
Antineoplásicos/química , Antineoplásicos/uso terapêutico , Irinotecano/química , Nanofibras/química , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Ratos Wistar , Rabdomiossarcoma/tratamento farmacológico , Rabdomiossarcoma/metabolismo
7.
JAMA Ophthalmol ; 136(7): 747-752, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29799944

RESUMO

Importance: Multi-institutional collaborative studies that include large patient populations for the management of retinoblastoma with histopathological risk factors could provide important information for patient management. Objective: To evaluate the implementation of a strategy for the management of nonmetastatic unilateral retinoblastoma in children based on standardized diagnostic and treatment criteria. Design, Setting, and Participants: This single-arm prospective study applied a strategy based on a single-center experience. The setting was a multicenter study in Latin America (Grupo de America Latina de Oncologia Pediatrica [GALOP]). Participants were children with nonmetastatic unilateral retinoblastoma (staged with the International Retinoblastoma Staging System). The study opened on July 1, 2008, and closed on December 31, 2014. Follow-up was updated until June 30, 2017. Interventions: Stage 0 patients (without enucleation) were given conservative therapy without a protocol. Stage I patients (with enucleation and no residual tumor) were divided into a high-risk group (retrolaminar invasion and/or scleral invasion) and a low-risk group (all remaining patients). High-risk children received adjuvant chemotherapy with 4 alternating cycles of regimen 1 (cyclophosphamide [65 mg/kg/d] [plus sodium-2-mercaptoethane sulfonate], idarubicin hydrochloride [10 mg/m2/d], and vincristine sulfate [0.05 mg/kg/d]) and 4 cycles of regimen 2 (carboplatin [500 mg/m2/d, days 1 and 2] and etoposide [100 mg/m2/d, days 1-3]). Low-risk children did not receive adjuvant therapy. Children with buphthalmia received neoadjuvant and adjuvant chemotherapy for a total of 8 cycles. Main Outcomes and Measures: Probability of event-free survival (extraocular relapse and death from any cause were considered events). Results: Among 187 children registered in the study, 175 were evaluable (92 [52.5%] female; median age, 22 months; age range, 3-100 months). Forty-two were stage 0 children, 84 were stage I low-risk children, and 42 were stage I high-risk children; there were 7 children in the buphthalmia group. With a median follow-up of 46 months, the 3-year probability of event-free survival was 0.97 (95% CI, 0.94-0.99), and the probability of overall survival was 0.98 (95% CI, 0.94-1.00). Stage 0 patients had no events, stage I low-risk patients had 1 event (orbital relapse treated with second-line therapy), stage I high-risk patients had 2 events (1 central nervous system relapse and 1 death from sepsis), and the buphthalmia group had 1 event (orbital relapse, followed by central nervous relapse and death). Conclusions and Relevance: Adjuvant therapy may be effective for high-risk unilateral retinoblastoma but is toxic, and neoadjuvant chemotherapy for buphthalmus appears feasible.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Retina/tratamento farmacológico , Retinoblastoma/tratamento farmacológico , Carboplatina/administração & dosagem , Criança , Pré-Escolar , Ciclofosfamida/administração & dosagem , Intervalo Livre de Doença , Etoposídeo/administração & dosagem , Enucleação Ocular , Feminino , Humanos , Hidroftalmia/complicações , Idarubicina/administração & dosagem , Lactente , Masculino , Mesna/administração & dosagem , Metástase Neoplásica , Estadiamento de Neoplasias , Estudos Prospectivos , Neoplasias da Retina/mortalidade , Neoplasias da Retina/patologia , Retinoblastoma/mortalidade , Retinoblastoma/patologia , Taxa de Sobrevida , Vincristina/administração & dosagem
9.
Clin Cancer Res ; 24(6): 1355-1363, 2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29351917

RESUMO

Purpose: The classification of medulloblastoma into WNT, SHH, group 3, and group 4 subgroups has become of critical importance for patient risk stratification and subgroup-tailored clinical trials. Here, we aimed to develop a simplified, clinically applicable classification approach that can be implemented in the majority of centers treating patients with medulloblastoma.Experimental Design: We analyzed 1,577 samples comprising previously published DNA methylation microarray data (913 medulloblastomas, 457 non-medulloblastoma tumors, 85 normal tissues), and 122 frozen and formalin-fixed paraffin-embedded medulloblastoma samples. Biomarkers were identified applying stringent selection filters and Linear Discriminant Analysis (LDA) method, and validated using DNA methylation microarray data, bisulfite pyrosequencing, and direct-bisulfite sequencing.Results: Using a LDA-based approach, we developed and validated a prediction method (EpiWNT-SHH classifier) based on six epigenetic biomarkers that allowed for rapid classification of medulloblastoma into the clinically relevant subgroups WNT, SHH, and non-WNT/non-SHH with excellent concordance (>99%) with current gold-standard methods, DNA methylation microarray, and gene signature profiling analysis. The EpiWNT-SHH classifier showed high prediction capacity using both frozen and formalin-fixed material, as well as diverse DNA methylation detection methods. Similarly, we developed a classifier specific for group 3 and group 4 tumors, based on five biomarkers (EpiG3-G4) with good discriminatory capacity, allowing for correct assignment of more than 92% of tumors. EpiWNT-SHH and EpiG3-G4 methylation profiles remained stable across tumor primary, metastasis, and relapse samples.Conclusions: The EpiWNT-SHH and EpiG3-G4 classifiers represent a new simplified approach for accurate, rapid, and cost-effective molecular classification of single medulloblastoma DNA samples, using clinically applicable DNA methylation detection methods. Clin Cancer Res; 24(6); 1355-63. ©2018 AACR.


Assuntos
Biomarcadores Tumorais , Neoplasias Cerebelares/diagnóstico , Neoplasias Cerebelares/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Meduloblastoma/diagnóstico , Meduloblastoma/genética , Biópsia , Ilhas de CpG , Metilação de DNA , Epigênese Genética , Epigenômica/métodos , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Reprodutibilidade dos Testes
10.
Cancer Cell ; 32(4): 520-537.e5, 2017 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-28966033

RESUMO

We collated data from 157 unpublished cases of pediatric high-grade glioma and diffuse intrinsic pontine glioma and 20 publicly available datasets in an integrated analysis of >1,000 cases. We identified co-segregating mutations in histone-mutant subgroups including loss of FBXW7 in H3.3G34R/V, TOP3A rearrangements in H3.3K27M, and BCOR mutations in H3.1K27M. Histone wild-type subgroups are refined by the presence of key oncogenic events or methylation profiles more closely resembling lower-grade tumors. Genomic aberrations increase with age, highlighting the infant population as biologically and clinically distinct. Uncommon pathway dysregulation is seen in small subsets of tumors, further defining the molecular diversity of the disease, opening up avenues for biological study and providing a basis for functionally defined future treatment stratification.


Assuntos
Neoplasias do Tronco Encefálico/genética , Glioma/genética , Histonas/genética , Mutação , Adolescente , Neoplasias do Tronco Encefálico/patologia , Proteínas de Ciclo Celular/genética , Criança , Pré-Escolar , DNA Topoisomerases Tipo I/genética , Exoma , Proteínas F-Box/genética , Proteína 7 com Repetições F-Box-WD , Feminino , Dosagem de Genes , Glioma/patologia , Humanos , Lactente , Recém-Nascido , Masculino , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Ubiquitina-Proteína Ligases/genética , Adulto Jovem
11.
J Control Release ; 264: 34-44, 2017 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-28830790

RESUMO

Treatment of retinoblastoma -a pediatric cancer of the developing retina- might benefit from strategies to inhibit the blood-retinal barrier (BRB). The potent anticancer agent topotecan is a substrate of efflux transporters BCRP and P-gp, which are expressed at the BRB to restrict vitreous and retinal distribution of xenobiotics. In this work we have studied vitreous and retinal distribution, tumor accumulation and antitumor activity of topotecan, using pantoprazole as inhibitor of BCRP and P-gp. We used rabbit and mouse eyes as BRB models and patient-derived xenografts as retinoblastoma models. To validate the rabbit BRB model we stained BCRP and P-gp in the retinal vessels. Using intravitreous microdialysis we showed that the penetration of the rabbit vitreous by lactone topotecan increased significantly upon concomitant administration of pantoprazole (P=0.0285). Pantoprazole also increased topotecan penetration of the mouse vitreous, measured as the vitreous-to-plasma topotecan concentration ratio at the steady state (P=0.0246). Pantoprazole increased topotecan antitumor efficacy and intracellular penetration in retinoblastoma in vitro, but did not enhance intratumor drug distribution and survival in mice bearing the intraocular human tumor HSJD-RBT-2. Anatomical differences with the clinical setting likely limited our in vivo study, since xenografts were poorly vascularized masses that loaded most of the vitreous compartment. We conclude that pharmacological modulation of the BRB is feasible, enhances anticancer drug distribution into the vitreous and might have clinical implications in retinoblastoma. CHEMICAL COMPOUNDS INCLUDED IN THIS MANUSCRIPT: Topotecan (PubChem CID: 60700) Pantoprazole sodium (PubChem CID: 15008962).


Assuntos
2-Piridinilmetilsulfinilbenzimidazóis/farmacologia , Barreira Hematorretiniana/efeitos dos fármacos , Neoplasias da Retina/tratamento farmacológico , Retinoblastoma/tratamento farmacológico , Inibidores da Topoisomerase I/uso terapêutico , Topotecan/uso terapêutico , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Barreira Hematorretiniana/metabolismo , Humanos , Camundongos Nus , Pantoprazol , Coelhos , Neoplasias da Retina/genética , Neoplasias da Retina/metabolismo , Retinoblastoma/genética , Retinoblastoma/metabolismo , Inibidores da Topoisomerase I/farmacocinética , Topotecan/farmacocinética , Corpo Vítreo/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Nat Med ; 23(4): 483-492, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28263309

RESUMO

Diffuse intrinsic pontine glioma (DIPG) is an aggressive brain tumor that is located in the pons and primarily affects children. Nearly 80% of DIPGs harbor mutations in histone H3 genes, wherein lysine 27 is substituted with methionine (H3K27M). H3K27M has been shown to inhibit polycomb repressive complex 2 (PRC2), a multiprotein complex responsible for the methylation of H3 at lysine 27 (H3K27me), by binding to its catalytic subunit EZH2. Although DIPGs with the H3K27M mutation show global loss of H3K27me3, several genes retain H3K27me3. Here we describe a mouse model of DIPG in which H3K27M potentiates tumorigenesis. Using this model and primary patient-derived DIPG cell lines, we show that H3K27M-expressing tumors require PRC2 for proliferation. Furthermore, we demonstrate that small-molecule EZH2 inhibitors abolish tumor cell growth through a mechanism that is dependent on the induction of the tumor-suppressor protein p16INK4A. Genome-wide enrichment analyses show that the genes that retain H3K27me3 in H3K27M cells are strong polycomb targets. Furthermore, we find a highly significant overlap between genes that retain H3K27me3 in the DIPG mouse model and in human primary DIPGs expressing H3K27M. Taken together, these results show that residual PRC2 activity is required for the proliferation of H3K27M-expressing DIPGs, and that inhibition of EZH2 is a potential therapeutic strategy for the treatment of these tumors.


Assuntos
Neoplasias do Tronco Encefálico/genética , Proliferação de Células/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Glioma/genética , Histonas/genética , Animais , Benzamidas/farmacologia , Neoplasias Encefálicas/genética , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Cromatografia Líquida , Inibidor p16 de Quinase Dependente de Ciclina/efeitos dos fármacos , Inibidor p16 de Quinase Dependente de Ciclina/genética , Modelos Animais de Doenças , Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Técnicas de Inativação de Genes , Glioblastoma/genética , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Indazóis/farmacologia , Camundongos , Camundongos SCID , Terapia de Alvo Molecular , Mutação , Transplante de Neoplasias , Células-Tronco Neurais , Complexo Repressor Polycomb 2/genética , Piridonas/farmacologia , Espectrometria de Massas em Tandem , Proteína Supressora de Tumor p14ARF/efeitos dos fármacos , Proteína Supressora de Tumor p14ARF/genética
13.
PLoS One ; 11(7): e0160094, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27467588

RESUMO

Current treatment of retinoblastoma involves using the maximum dose of chemotherapy that induces tumor control and is tolerated by patients. The impact of dose and schedule on the cytotoxicity of chemotherapy has not been studied. Our aim was to gain insight into the cytotoxic and antiangiogenic effect of the treatment scheme of chemotherapy used in retinoblastoma by means of different in vitro models and to evaluate potential effects on multi-drug resistance proteins. Two commercial and two patient-derived retinoblastoma cell types and two human vascular endothelial cell types were exposed to increasing concentrations of melphalan or topotecan in a conventional (single exposure) or metronomic (7-day continuous exposure) treatment scheme. The concentration of chemotherapy causing a 50% decrease in cell proliferation (IC50) was determined by MTT and induction of apoptosis was evaluated by flow cytometry. Expression of ABCB1, ABCG2 and ABCC1 after conventional or metronomic treatments was assessed by RT-qPCR. We also evaluated the in vivo response to conventional (0.6 mg/kg once a week for 2 weeks) and metronomic (5 days a week for 2 weeks) topotecan in a retinoblastoma xenograft model. Melphalan and topotecan were cytotoxic to both retinoblastoma and endothelial cells after conventional and metronomic treatments. A significant decrease in the IC50 (median, 13-fold; range: 3-23) was observed following metronomic chemotherapy treatment in retinoblastoma and endothelial cell types compared to conventional treatment (p<0.05). Metronomic topotecan or melphalan significantly inhibited in vitro tube formation in HUVEC and EPC compared to vehicle-treated cells (p<0.05). Both treatment schemes induced apoptosis and/or necrosis in all cell models. No significant difference was observed in the expression of ABCB1, ABCC1 or ABCG2 when comparing cells treated with melphalan or topotecan between treatment schedules at the IC50 or with control cells (p>0.05). In mice, continuous topotecan lead to significantly lower tumor volumes compared to conventional treatment after 14 days of treatment (p<0.05). Continuous exposure to melphalan or topotecan increased the chemosensitivity of retinoblastoma and endothelial cells to both chemotherapy agents with lower IC50 values compared to short-term treatment. These findings were validated in an in vivo model. None of the dosing modalities induced multidrug resistance mechanisms while apoptosis was the mechanism of cell death after both treatment schedules. Metronomic chemotherapy may be a valid option for retinoblastoma treatment allowing reductions of the daily dose.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Antineoplásicos/uso terapêutico , Retinoblastoma/tratamento farmacológico , Inibidores da Angiogênese/farmacologia , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Xenoenxertos , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos , Camundongos Nus , Retinoblastoma/patologia
14.
Cancer Lett ; 380(1): 10-9, 2016 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-27319373

RESUMO

Translational research in retinoblastoma - a pediatric tumor that originates during the development of the retina - would be improved by the creation of new patient-derived models. Using tumor samples from enucleated eyes we established a new battery of preclinical models that grow in vitro in serum-free medium and in vivo in immunodeficient mice. To examine whether the new xenografts recapitulate human disease and disseminate from the retina to the central nervous system, we evaluated their histology and the presence of molecular markers of dissemination that are used in the clinical setting to detect extraocular metastases. We evaluated GD2 synthase and CRX as such markers and generated a Taqman real-time quantitative PCR method to measure CRX mRNA for rapid, sensitive and specific quantification of local and metastatic tumor burden. This approach was able to detect 1 human retinoblastoma cell in 100.000 mouse brain cells. Our research adds novel preclinical tools for the discovery of new retinoblastoma treatments for clinical translation.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/enzimologia , Movimento Celular , Proteínas de Homeodomínio/metabolismo , N-Acetilgalactosaminiltransferases/metabolismo , Neoplasias Experimentais/enzimologia , Neoplasias da Retina/enzimologia , Retinoblastoma/enzimologia , Transativadores/metabolismo , Animais , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/secundário , Linhagem Celular Tumoral , Pré-Escolar , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Proteínas de Homeodomínio/genética , Humanos , Lactente , Camundongos Nus , N-Acetilgalactosaminiltransferases/genética , Micrometástase de Neoplasia , Transplante de Neoplasias , Neoplasias Experimentais/genética , Neoplasias Experimentais/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Neoplasias da Retina/genética , Neoplasias da Retina/patologia , Retinoblastoma/genética , Retinoblastoma/secundário , Transdução de Sinais , Transativadores/genética , Células Tumorais Cultivadas
15.
Oncotarget ; 7(13): 16112-29, 2016 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-26893368

RESUMO

The calcium-sensing receptor is a G protein-coupled receptor that exerts cell-type specific functions in numerous tissues and some cancers. We have previously reported that this receptor exhibits tumor suppressor properties in neuroblastoma. We have now assessed cinacalcet, an allosteric activator of the CaSR approved for clinical use, as targeted therapy for this developmental tumor using neuroblastoma cell lines and patient-derived xenografts (PDX) with different MYCN and TP53 status. In vitro, acute exposure to cinacalcet induced endoplasmic reticulum stress coupled to apoptosis via ATF4-CHOP-TRB3 in CaSR-positive, MYCN-amplified cells. Both phenotypes were partially abrogated by phospholipase C inhibitor U73122. Prolonged in vitro treatment also promoted dose- and time-dependent apoptosis in CaSR-positive, MYCN-amplified cells and, irrespective of MYCN status, differentiation in surviving cells. Cinacalcet significantly inhibited tumor growth in MYCN-amplified xenografts and reduced that of MYCN-non amplified PDX. Morphology assessment showed fibrosis in MYCN-amplified xenografts exposed to the drug. Microarrays analyses revealed up-regulation of cancer-testis antigens (CTAs) in cinacalcet-treated MYCN-amplified tumors. These were predominantly CTAs encoded by genes mapping on chromosome X, which are the most immunogenic. Other modulated genes upon prolonged exposure to cinacalcet were involved in differentiation, cell cycle exit, microenvironment remodeling and calcium signaling pathways. CTAs were up-regulated in PDX and in vitro models as well. Moreover, progressive increase of CaSR expression upon cinacalcet treatment was seen both in vitro and in vivo. In summary, cinacalcet reduces neuroblastoma tumor growth and up-regulates CTAs. This effect represents a therapeutic opportunity and provides surrogate circulating markers of neuroblastoma response to this treatment.


Assuntos
Antígenos de Neoplasias/biossíntese , Antineoplásicos/farmacologia , Cinacalcete/farmacologia , Neuroblastoma/patologia , Animais , Antígenos de Neoplasias/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Camundongos , Camundongos Nus , Proteína Proto-Oncogênica N-Myc/genética , Neuroblastoma/metabolismo , Receptores de Detecção de Cálcio/agonistas , Receptores de Detecção de Cálcio/efeitos dos fármacos , Proteína Supressora de Tumor p53/genética , Regulação para Cima , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Pediatr Dermatol ; 32(6): e255-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26446951

RESUMO

Cutaneous mucinosis in infancy is rare. We report an infant with multiple congenital papules distributed over the trunk, neck, and extremities. These papules were mainly dispersed, but they also coalesced into plaques. Histopathologic findings showed features of cutaneous mucinosis of infancy (CMI). Over 2 years of follow-up, we observed that the preexisting lesions on the lower back and left trunk progressively increased in size, and a few new scattered papules continued to appear, mainly on the trunk; several lesions spontaneously resolved with no further complications. CMI is considered to be a persistent cutaneous disorder, even though spontaneously regressing cases have rarely been reported. This case demonstrates the broad clinical spectrum of CMI, with progressive, eruptive, and spontaneously involuting lesions all present in the same patient. This condition should be considered in the differential diagnosis of congenital or infantile-onset papules and plaques, especially those yellowish in color.


Assuntos
Mucinoses/diagnóstico , Dermatopatias/diagnóstico , Diagnóstico Diferencial , Feminino , Humanos , Lactente , Mucinoses/congênito , Pele/patologia , Dermatopatias/congênito
17.
Childs Nerv Syst ; 31(9): 1447-59, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26156776

RESUMO

INTRODUCTION: In pediatric population (0-18 years), low-grade gliomas (PLGG) are the most frequent brain tumors and majority are amenable for surgical removal. PATIENTS AND METHODS: A retrospective review of 198 children diagnosed with PLGG between 1980 and 2010 at HSJD was carried out. Several variables were studied to find prognostic factors related to the outcomes (progression-free survival (PFS) and overall survival (OS)). RESULTS: Median age at onset was 88.8 months (3.1 to 214.5 months, SD 53). Surgery was performed in 175 patients (88.4%), achieving gross total resection (GTR) in 77 (44%), subtotal resection (STR) in 87 (49.7%), and 11 (6.3%) biopsies. Pathological review classified 84 tumors as WHO grade I (48%) and 89 as grade II (50.8%). Adjuvant therapy (AT) was given to 75 patients (37.9%), radiotherapy in 24 (12.1%), chemotherapy in 33 (16.7%), and combined in 18 (9.1%). Sixteen patients (8.1%) died, 89 (43.4%) are alive with no evidence of disease, and 93 (47%) alive with disease, median follow-up 65.2 months. Outcome is significantly correlated with age (p = 0001, worse OS for patients younger than 12 months) and extent of tumor resection (p < 0001). OS for GTR/STR/biopsy was >200, 154.3, and 101.9 months, respectively. Patients treated with AT presented worse OS/PFS (p < 0.001) than those not treated. Histology was non significantly related to outcomes. CONCLUSION: In our series of PLGG, the best prognostic markers are tumor location (cerebellar) and the extent of tumor resection (GTR). Infants and patients who require adjuvant therapy because of tumor progression or recurrence have worse outcome.


Assuntos
Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/terapia , Glioma/diagnóstico , Glioma/terapia , Procedimentos Neurocirúrgicos/métodos , Adolescente , Antineoplásicos/uso terapêutico , Neoplasias Encefálicas/complicações , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Glioma/complicações , Humanos , Hidrocefalia/etiologia , Lactente , Recém-Nascido , Masculino , Modelos de Riscos Proporcionais , Estatísticas não Paramétricas
18.
Epigenomics ; 7(7): 1137-53, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26067621

RESUMO

AIM: To define the DNA methylation landscape of neuroblastoma and its clinicopathological impact. MATERIALS & METHODS: Microarray DNA methylation data were analyzed and associated with functional/regulatory genome annotation data, transcriptional profiles and clinicobiological parameters. RESULTS: DNA methylation changes in neuroblastoma affect not only promoters but also intragenic and intergenic regions at cytosine-phosphate-guanine (CpG) and non-CpG sites, and target functional chromatin domains of development and cancer-related genes such as CCND1. Tumors with diverse clinical risk showed differences affecting CpG and, remarkably, non-CpG sites. Non-CpG methylation observed essentially in clinically favorable cases was associated with the differentiation status of neuroblastoma and expression of key genes such as ALK. CONCLUSION: This epigenetic fingerprint of neuroblastoma provides new insights into the pathogenesis and clinical behavior of this pediatric tumor.


Assuntos
Neoplasias Encefálicas/genética , Ciclina D1/genética , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Neuroblastoma/genética , Receptores Proteína Tirosina Quinases/genética , Quinase do Linfoma Anaplásico , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/mortalidade , Linhagem Celular Tumoral , Criança , Pré-Escolar , Cromatina/química , Cromatina/metabolismo , Ilhas de CpG , Ciclina D1/metabolismo , Impressões Digitais de DNA , Metilação de DNA , DNA Intergênico , Feminino , Perfilação da Expressão Gênica , Genoma Humano , Humanos , Lactente , Masculino , Neuroblastoma/diagnóstico , Neuroblastoma/metabolismo , Neuroblastoma/mortalidade , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Regiões Promotoras Genéticas , Receptores Proteína Tirosina Quinases/metabolismo , Análise de Sobrevida
19.
Cancer Discov ; 4(11): 1326-41, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25186949

RESUMO

UNLABELLED: Pediatric Ewing sarcoma is characterized by the expression of chimeric fusions of EWS and ETS family transcription factors, representing a paradigm for studying cancers driven by transcription factor rearrangements. In this study, we describe the somatic landscape of pediatric Ewing sarcoma. These tumors are among the most genetically normal cancers characterized to date, with only EWS-ETS rearrangements identified in the majority of tumors. STAG2 loss, however, is present in more than 15% of Ewing sarcoma tumors; occurs by point mutation, rearrangement, and likely nongenetic mechanisms; and is associated with disease dissemination. Perhaps the most striking finding is the paucity of mutations in immediately targetable signal transduction pathways, highlighting the need for new therapeutic approaches to target EWS-ETS fusions in this disease. SIGNIFICANCE: We performed next-generation sequencing of Ewing sarcoma, a pediatric cancer involving bone, characterized by expression of EWS-ETS fusions. We found remarkably few mutations. However, we discovered that loss of STAG2 expression occurs in 15% of tumors and is associated with metastatic disease, suggesting a potential genetic vulnerability in Ewing sarcoma.


Assuntos
Antígenos Nucleares/genética , Neoplasias Ósseas/genética , Sarcoma de Ewing/genética , Antígenos Nucleares/metabolismo , Neoplasias Ósseas/metabolismo , Linhagem Celular Tumoral , Criança , DNA de Neoplasias/genética , Feminino , Rearranjo Gênico , Genômica , Humanos , Masculino , Mutação , Sarcoma de Ewing/metabolismo , Análise de Sequência de DNA
20.
Acta Ophthalmol ; 92(3): 209-15, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24868582

RESUMO

PURPOSE: To report the efficacy and complications of intra-ophthalmic artery melphalan (IAM) for treatment of patients with advanced intra-ocular retinoblastoma. METHODS: Patients with newly diagnosed, unilateral, group D retinoblastoma were included in a phase II protocol. Children with relapsed-refractory disease after systemic chemoreduction were later treated under the same guidelines.Melphalan (3­5 mg/procedure) was injected through a 1.2 F microcatheter placed into the ophthalmic artery every 21 days. RESULTS: Eleven patients (12 eyes, eight as primary treatment) received 33 IAM procedures. The phase II protocol closed prematurely because of low accrual. The IAM technique was overall safe and could be performed successfully in 31 of 33(94%) attempts. After the second administration of IAM, very good partial response was achieved in all treated eyes. With a median follow-up time of 29.5 months (range 6­57), ocular salvage was achieved in 7 of 12 (58%) eyes. No systemic adverse events were observed. Two patients developed diffuse arteriolar sclerosis, hyperpigmentation of the retinal pigment epithelium and partial retinal atrophy after the second IAM. Both eyes were preserved with no tumour activity, good motility and perception of light, 56 and 30 months after the last IAM treatment. Multinucleated macrophages with intracytoplasmic foreign material were found in the choroid and the retina in 2 of 5 enucleated eyes. CONCLUSION: Our study reports the activity and reproducibility of IAM in advanced retinoblastoma but also underlines the challenges of performing prospective studies on this treatment modality. Toxicity was limited to only ocular vascular events.


Assuntos
Melfalan/administração & dosagem , Neoplasias da Retina/tratamento farmacológico , Retinoblastoma/tratamento farmacológico , Antineoplásicos Alquilantes/administração & dosagem , Pré-Escolar , Relação Dose-Resposta a Droga , Feminino , Angiofluoresceinografia , Seguimentos , Fundo de Olho , Humanos , Lactente , Recém-Nascido , Injeções Intra-Arteriais , Masculino , Artéria Oftálmica , Estudos Prospectivos , Neoplasias da Retina/diagnóstico , Retinoblastoma/diagnóstico , Fatores de Tempo , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA