Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
BMC Res Notes ; 6: 327, 2013 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-23954069

RESUMO

BACKGROUND: Hiccup (Singultus) is a sudden and involuntary contraction of the diaphragm followed by a sharp closure of the epiglottis which results in the production of a specific "hic" sound. Normally, hiccups are treated without intervention. Intractable hiccups occur rarely but are a disturbing symptom underlying other health related disorders. CASE PRESENTATION: We report the clinical case of a 67-year-old male patient with myocardial infarction accompanied by intractable hiccups during the course of 8 months, and who was non-responsive to chlorpromazine or metoclopramide, and baclofen; drugs routinely used to treat this condition. This sustained hiccup had severely restricted the patient's ability to intake food and sleep. To explore alternative treatments, we investigated the adjuvant administration of lansoprazole, dimenhydrinate and clonazepam in this patient. We discovered that this drug combination was capable of successfully terminating his intractable hiccups, with no further evidence of recurrence. No similar treatment is previously reported for intractable hiccups. We further suggest a hypothesis concerning a potential mechanism on the anti-hiccup effect of dimenhydrinate. CONCLUSION: We identified that the adjuvant use of lansoprazole, clonazepam and dimenhydrinate was capable of attenuating the symptoms of our patient with intractable hiccups.


Assuntos
Esofagite Péptica/complicações , Gastrite/complicações , Soluço/tratamento farmacológico , Infarto do Miocárdio/complicações , Idoso , Clonazepam/administração & dosagem , Dimenidrinato/administração & dosagem , Soluço/complicações , Humanos , Lansoprazol/administração & dosagem , Masculino
2.
Future Oncol ; 9(8): 1215-29, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23902250

RESUMO

AIM: The treatment of pediatric low-grade gliomas with current treatment modalities still remains ineffective among a subset of patients; hence, justifying the need to further investigate more effective therapies. Dipotassium bisperoxo (picolinato) oxovanadate V (Bpv[pic]), is a derivative of the trace metal vanadium and a potent inhibitor of protein tyrosine phosphatases, which are important mediators of oncogenic and tumor suppressive activities in cancers. In this study, we undertook a preclinical evaluation of the antineoplastic functions of Bpv(pic) in the treatment of pediatric low-grade gliomas. MATERIALS & METHODS: We utilized pediatric low-grade glioma cell lines (Res186, Res259 and R286) in a wide variety of cancer assays to determine whether Bpv(pic) can abrogate the neoplastic properties of these cells. RESULTS: Our preclinical evaluation of the antineoplastic properties of Bpv(pic) in pediatric low-grade gliomas reveals a significant dose-dependent decrease in cell viability as a consequence of decreased proliferation and sustained induction of growth arrest and apoptosis. Bpv(pic) significantly decreases cell migration/invasion and anchorage-independent growth in soft agarose. Within cells, Bpv(pic) functions by attenuating CDC25A activity, and by decreasing the expression of multiple protein tyrosine phosphatases, DNA repair genes, microtubule-associated genes, such as PLK1, AURKA and HDAC6, and conversely augmenting the expression of proapoptotic mediators such as BAK, AIFM and CTSL1. CONCLUSION: Collectively, our data strongly suggest novel evidence of Bpv(pic) being a potent antineoplastic drug and a suitable alternative for the treatment of pediatric low-grade gliomas.


Assuntos
Antineoplásicos/administração & dosagem , Sobrevivência Celular/efeitos dos fármacos , Glioma/tratamento farmacológico , Compostos Organometálicos/administração & dosagem , Antineoplásicos/efeitos adversos , Apoptose/efeitos dos fármacos , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/induzido quimicamente , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/classificação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioma/genética , Glioma/patologia , Humanos , Estadiamento de Neoplasias , Compostos Organometálicos/efeitos adversos , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Pediatria/métodos , Proteínas Tirosina Fosfatases/antagonistas & inibidores , Fosfatases cdc25/metabolismo
3.
Cancer Lett ; 335(1): 109-18, 2013 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-23402815

RESUMO

Low grade gliomas are a heterogeneous group of tumours representing the most common form of neoplasms in the central nervous system among children. Although gross total resection remains the principal treatment, it is often impractical especially for the resection of tumours within eloquent regions of the brain. Instead Radiotherapy is utilised in such cases, but because of its associated toxicities, it is refrained from use among younger children. These limitations coupled with hypersensitivity and toxicities associated with some commonly used chemotherapeutic agents, have ignited the need to search for safer and more effective treatments for paediatric low grade gliomas. In this study, we investigated the EM011 drug on the growth of two pilocytic and one diffuse paediatric astrocytoma cell lines, using an assortment of cancer assays. We discovered that treatments of low grade gliomas with EM011 abrogated cell viability by inducing a decrease in cell proliferation and an arrest in the S and G2M cell cycle phases, followed by a converse increase in apoptosis in a dose and time dependent manner. The cell migratory and invasion indices, as well as anchorage independent growth in soft agarose, were significantly attenuated. These findings were mechanistically associated with a transient release of AIF, a disruption of microtubule architecture, and a decline in the expression of key genes which drive cancer progression including EGFR, mTORC1, JUN and multiple MMPs. In fact, the activity of MMP2 was also perturbed by EM011. These findings, in conjunction with the insignificant adverse side effects established from other studies, make EM011 an appealing chemotherapeutic agent for the treatment of paediatric low grade gliomas.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Dioxóis/farmacologia , Glioma/tratamento farmacológico , Isoquinolinas/farmacologia , Moduladores de Tubulina/farmacologia , Apoptose/efeitos dos fármacos , Fator de Indução de Apoptose/metabolismo , Neoplasias Encefálicas/patologia , Adesão Celular , Linhagem Celular Tumoral/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Criança , Gelatinases/metabolismo , Expressão Gênica/efeitos dos fármacos , Glioma/patologia , Humanos , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Gradação de Tumores , Pontos de Checagem da Fase S do Ciclo Celular/efeitos dos fármacos , Transcriptoma
4.
Am J Med Genet A ; 161A(4): 803-8, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23444262

RESUMO

Agnathia-otocephaly is a rare craniofacial malformation complex that is caused by de novo heterozygous and biallelic mutations in PRRX1 in two unrelated babies, respectively. We studied the PRRX1 gene in a non-consanguineous Indonesian female infant who was diagnosed prenatally with severe retrognathia (bilateral Pruzansky type III). Her older affected brother died shortly after birth and had agnathia-otocephaly. A c.266_269dupAAAA frameshift mutation in the poly A tract in PRRX1 was identified in the proband while her father only had an inframe duplication (c.267_269dupAAA) of the adenosine trinucleotide residue. Expression of both mutations in COS7 cells showed loss of function of the frame shift mutation only. Results of SNP genotyping coupled with recurrence of this novel mutation in this family are consistent with a paternally derived germline mosaicism rather than autosomal recessive inheritance as predicted by the family history. Severe retrognathia (bilateral Pruzansky III) and agnathia-otocephaly represent a spectrum of craniofacial malformations in this family.


Assuntos
Anormalidades Craniofaciais/genética , Mutação da Fase de Leitura , Proteínas de Homeodomínio/genética , Anormalidades Maxilomandibulares/genética , Animais , Autopsia , Células COS , Chlorocebus aethiops , Anormalidades Craniofaciais/diagnóstico , Replicação do DNA , Evolução Fatal , Feminino , Expressão Gênica , Genes Reporter , Heterozigoto , Humanos , Recém-Nascido , Anormalidades Maxilomandibulares/diagnóstico , Mosaicismo , Fases de Leitura Aberta
5.
Fetal Pediatr Pathol ; 32(4): 293-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23301910

RESUMO

We report a new and rare case of recurrent anencephaly in a family with no other apparent abnormalities. The karyotypes of the family and all affected subjects were normal. Thorough mutational analyses of VANGL1 of chromosome 1p13.1 and FOXN1 of chromosome 17q11-q12, genes that are associated with phenotypes of the anencephaly spectrum, unfortunately did not disclose any DNA variations in an affected fetus of this family. The etiology of recurrent anencephaly in this family is therefore due to mutations in genes yet to be discovered, perhaps of the planar cell polarity pathway, or to possible environmental gestational factors during development.


Assuntos
Anencefalia/genética , Proteínas de Transporte/genética , Fatores de Transcrição Forkhead/genética , Proteínas de Membrana/genética , Adulto , Análise Mutacional de DNA , Feminino , Humanos , Linhagem , Reação em Cadeia da Polimerase Via Transcriptase Reversa
6.
Cancer Lett ; 330(1): 96-105, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23201138

RESUMO

Pediatric low grade gliomas are the most common central nervous system tumors and are still incurable among a subset of patients despite current treatment modalities. Steroid biosynthesis occurs in a wide variety of organs including the brain, to mediate an assortment of functions, including a proposed role in the growth of gliomas. Hence, targeting steroid biosynthesis and/or their signaling pathways, is anticipated as an effective approach for treating gliomas. In this study, we investigated whether our chemical library of steroid inhibitors can modulate the growth of pediatric low grade glioma cell lines (Res186, Res259, R286), and subsequently identified a potent inhibitor of 17ß-hydroxysteroid dehydrogenase type 3, referred to as DK16, which functions by attenuating cell viability, proliferation, migration/invasion and anchorage independent growth and conversely induces apoptosis and cell cycle arrest in a dose and duration dependent manner. Further investigations into the mechanisms of how DK16 functions showed that this drug increased the BAX/BCL2 expression ratio, induced phosphatidylserine externalization, and mitochondrial membrane depolarizations culminating to the release and nuclear translocation of AIF. In addition, treatments of low grade glioma cell lines with DK16 increased the expression of pro-apoptotic mediators including CDK2 and CTSL1, and with the converse diminished expression of pro-survival and migratory/invasion genes like PRKCA, TERT, MAPK8, MMP1 and MMP2. Our findings collectively demonstrate the potent anti-neoplastic properties of DK16, a steroid biosynthesis inhibitor, on the growth of pediatric low grade gliomas.


Assuntos
17-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Neoplasias Encefálicas/tratamento farmacológico , Glioma/tratamento farmacológico , Esteroides/antagonistas & inibidores , 17-Hidroxiesteroide Desidrogenases/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Criança , Ensaios de Seleção de Medicamentos Antitumorais , Glioma/metabolismo , Glioma/patologia , Humanos , Gradação de Tumores , Esteroides/biossíntese
7.
Cancer Lett ; 330(2): 130-40, 2013 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-23211539

RESUMO

Medulloblastomas are highly aggressive tumors of the cerebellum with an embryonal origin. Despite current treatment modalities which include a combination of surgery, chemotherapy and/or radiation, challenges still exist to effectively treat some patients, especially those within the younger age group. In an effort to find improved therapies, ongoing research led by world-wide teams have explored non-conventional therapeutic strategies, as well as examined the efficacy of several drugs in clinical trials among patients with Medulloblastomas. We outline in this article, recent advances on the efficacy and toxicity of numerous therapeutic agents including those that are DNA damaging agents, microtubules binding compounds, and those that are inhibitors of Topoisomerase and of the Notch and Hedgehog signaling pathway, which were assessed in recent Phase I and II clinical trials. Among these clinical trials, it is unfortunate that the outcomes were dismal with the majority of the patients with Medulloblastomas still succumbing to relapse after conventional therapies. Furthermore, it is yet to be established clearly the clinical efficacy of non-conventional therapies such as immunotherapy and gene therapy. Moreover, there is growing interest in proton therapy as a potential replacement for photon therapy, while high dose chemotherapy and autologous stem cell rescue may improve therapeutic efficacies. However, further research is needed to resolve the inherent toxicity from these novel therapeutic methods. In conclusion, novel therapies based on a better understanding of the biology of Medulloblastomas are pivotal in improving non-conventional therapies in the treatment of this deadly disease.


Assuntos
Neoplasias Cerebelares/terapia , Ensaios Clínicos como Assunto , Meduloblastoma/terapia , Inibidores da Angiogênese/uso terapêutico , Apoptose/efeitos dos fármacos , Terapia Genética , Humanos , Imunoterapia , Terapia com Prótons , Transplante de Células-Tronco , Inibidores da Topoisomerase/uso terapêutico , Transplante Autólogo , Moduladores de Tubulina/uso terapêutico
8.
J Pediatr Oncol ; 1: 32-40, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24749125

RESUMO

BACKGROUND: Pediatric gliomas, the most common solid childhood neoplasm, manifest unique molecular signatures that distinguish them from adult gliomas. Unfortunately, most studies have focused on adult gliomas and extrapolate the findings to treat pediatric gliomas. In this study, we assessed the efficacy of Targetin, a folate conjugated analogue of Noscapine, on the treatment of pediatric low and high grade gliomas. METHOD: An assortment of standard cancer assays were used with different drug doses and experimental durations. RESULTS: We found that pediatric glioma cells are more susceptible to lower doses of Targetin than parental Noscapine. Targetin functions by disrupting the microtubule network, and can likewise perturb DNA synthesis, delay the cellular transition within the S and G2M cell cycle phases, diminish anchorage independent growth and the migratory/invasiveness of pediatric glioma cells. Moreover, Targetin impairs the expression of several regulators of cancer progression belonging to prominent signalling pathways in pediatric gliomas; including Platelet Derived Growth Factor alpha and some members of the Mitogen Activated Protein Kinase cascade. CONCLUSION: Targetin has an excellent anti-neoplastic profile and functions to modulate the expression of several genes belonging to key cancer progression pathways in pediatric gliomas. Collectively, findings from this study highlight the usefulness of Targetin for the treatment of pediatric high and low grade gliomas.

9.
J Pediatr Oncol ; 1: 41-47, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24749126

RESUMO

BACKGROUND: Intervention aimed at disrupting or inhibiting newly formed vascular network is highly desired to attenuate the progression of angiogenesis-dependent diseases. In cancer, this is tightly associated with the generation of VEGF by hypoxia inducible factor-1α following its activation by hypoxia. In light of the multiple cellular roles played by microtubules and their involvement in the processing of the hypoxia inducible factor-1α transcript, modulation of microtubule dynamics is emerging as a logical approach to suppress tumor reliance on angiogenesis. Targetin is a novel noscapinoid that interferes with microtubule dynamicity and inhibits the growth of cell lines from many types of cancers. METHODS AND RESULTS: Utilizing in-vitro and ex-vivo angiogenic models, we discovered the vascular disrupting and anti-angiogenic properties of Targetin. Targetin disrupted pre-assembled capillary-like networks of human endothelial cells by severing cell-cell junctions, inhibiting endothelial cell proliferation and metabolic activity in the presence and absence of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). Furthermore, we show that Targetin significantly inhibits the formation of neovasculature network sprouting from rat aortic explants stimulated with proangiogenic stimuli, namely VEGF or bFGF. CONCLUSION: We conclude that Targetin is a potential clinically promising anti-angiogenic agent for the treatment of many diseases including cancers.

10.
J Prenat Med ; 6(3): 36-9, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23181171

RESUMO

OBJECTIVE: holoprosencephaly is the most common forebrain malformation syndrome with a multifactorial etiology. Currently, mutations are identified in 5-10% of non syndromic, non-chromosomal cases in at least 12 genes. We report the molecular prenatal diagnosis of a fetus with alobar holoprosencephaly. METHODS: CTG band karyotyping and array CGH genome-wide cytogenetic screenings were done, in conjunction with DNA sequence analyses of the SHH, ZIC2, SIX3 and TGIF genes in search of a molecular etiology and with comparison of findings to prior cases. RESULTS: standard CTG band karyotyping and array CGH genome-wide screening failed to identify plausible chromosome imbalances or structural anomalies. However, extensive sequencing of the genomic DNA from the fetus and both parents on all exon and exon-intron boundaries of the four most commonly mutated genes: SHH, ZIC2, SIX3 and TGIF, identified codon 100 of the sonic hedgehog (SHH) gene having a hotspot for loss-of-function mutations in our case and others. CONCLUSION: mutations in codon 100 of SHH were discovered in both sporadic and autosomal dominant inherited cases with evidence of variable expressivity and penetrance. Collectively, this study reinforces the complexity of genotype-phenotype correlations in the prenatal diagnosis of holoprosencephalic fetuses.

11.
Clin Invest Med ; 35(5): E246, 2012 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-23043706

RESUMO

PURPOSE: To present an assortment of molecular targets evident from a variety of signal transduction pathways and downstream effectors, which may have clinical relevance for the treatment of medulloblastomas. SOURCE: Data were archived from MEDLINE, using Boolean-formatted queries on the keywords including: medulloblastoma, pathology, prognosis, classification, tumor regression, inhibition, therapy, clinical trial, therapeutic agent, drug, molecular inhibitor, and signalling pathway. Only the most reputable articles were selected for critical analyses based on the qualitative assessment of the citation index, novelty of the findings and relevance to prospective novel ways of targeted therapies for medulloblastomas. PRINCIPAL FINDINGS: Medulloblastomas are highly aggressive embryonal tumors of the cerebellum, akin to primitive neuroectodermal tumors elsewhere in the brain. Current treatments for medulloblastomas which include a combination of surgery, chemotherapy and radiation, remain challenging especially, for younger patients; however, advances in understanding regulatory pathways in medulloblastomas are crucial to develop more effective therapeutic targets. Evidence showing several molecular and pharmacological targets within key signalling pathways, such as HEDGEHOG, WNT, NOTCH, Receptor Tyrosine Kinase (ERB, IGF-IR, c-MET, PDGF, Estrogen, p75NTR) , their downstream effectors like PI3K/AKT, c-MYC and STAT3, and as well as other targets such as telomerase and cytoskeletal elements, is summarized. All molecular and pharmacological targets have pivotal roles in the pathogenesis of medulloblastomas. Most importantly, these pathways can be effectively pharmacologically targeted to regress the growth of medulloblastomas. Pre-clinical studies were routinely undertaken with a variety of human and murine cell lines and as well as murine models of medulloblastomas. Thus far, two drugs which target the NOTCH and HEDGEHOG signalling have completed Phase I clinical trials, but with evidence of low efficacies; hence, reinforcing the importance of continuing investigations in search of new therapeutic agents and targets. CONCLUSION: Novel therapies, based on better understanding key biological pathways in medulloblastomas, hold promise for improved treatments in due course among patients with medulloblastomas.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Cerebelares/tratamento farmacológico , Meduloblastoma/tratamento farmacológico , Antineoplásicos/farmacologia , Neoplasias Cerebelares/metabolismo , Neoplasias Cerebelares/patologia , Cerebelo/metabolismo , Cerebelo/patologia , Humanos , Meduloblastoma/metabolismo , Meduloblastoma/patologia , Transdução de Sinais/efeitos dos fármacos
13.
Fetal Pediatr Pathol ; 31(5): 315-8, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22432933

RESUMO

We report a new case of a fetus with holoprosencephaly-polydactyly syndrome, also known as pseudo-trisomy 13 syndrome, and no other apparent abnormalities except for septal agenesis of the left lung. The fetal karyotype was normal. Mutational analysis of five genes (SHH, SIX3, TGIF, ZIC2, and GLI3), which are major genes associated with holoprosencephaly, did not disclose any mutational findings. We therefore propose that the abnormalities of our fetus support the demarcation of this syndrome as an autonomous phenotype. Specific diagnostic criteria for holoprosencephaly-polydactyly syndrome need to be complemented by the absence of mutations in the major holoprosencephaly genes.


Assuntos
Anormalidades Múltiplas/patologia , Transtornos Cromossômicos/diagnóstico , Macrossomia Fetal/diagnóstico , Deformidades Congênitas da Mão/diagnóstico , Holoprosencefalia/diagnóstico , Polidactilia/diagnóstico , Trissomia/diagnóstico , Anormalidades Múltiplas/genética , Aborto Eugênico , Adulto , Bandeamento Cromossômico , Transtornos Cromossômicos/genética , Cromossomos Humanos Par 13/genética , Análise Mutacional de DNA , Diagnóstico Diferencial , Evolução Fatal , Feminino , Macrossomia Fetal/genética , Deformidades Congênitas da Mão/genética , Holoprosencefalia/genética , Humanos , Masculino , Mutação , Polidactilia/genética , Trissomia/genética , Síndrome da Trissomia do Cromossomo 13 , Ultrassonografia Pré-Natal
14.
Am J Pathol ; 179(1): 462-76, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21703424

RESUMO

Malignant astrocytomas, the most common primary brain tumors, are predominantly fatal. Improved treatments will require a better understanding of the biological features of high-grade astrocytomas. To better understand the role of neuronal PAS 3 (NPAS3) in diseases in human beings, it was investigated as a candidate for astrocytomagenesis based on the presence of aberrant protein expression in greater than 70% of a human astrocytoma panel (n = 433) and most notably in surgically resected malignant lesions. In subsequent functional studies, it was concluded that NPAS3 exhibits features of a tumor-suppressor, which drives the progression of astrocytomas by modulating the cell cycle, proliferation, apoptosis, and cell migration/invasion and has a further influence on the viability of endothelial cells. Of clinical importance, absence of NPAS3 expression in glioblastomas was a significantly negative prognostic marker of survival. In addition, malignant astrocytomas lacking NPAS3 expression demonstrated loss of function mutations, which were associated with loss of heterozygosity. While overexpressed NPAS3 in malignant glioma cell lines significantly suppressed transformation, the converse decreased expression considerably induced more aggressive growth. In addition, knockdown NPAS3 expression in a human astrocyte cell line in concert with the human papillomavirus E6 and E7 oncogenes induced growth of malignant astrocytomas. In conclusion, NPAS3 drives the progression of human malignant astrocytomas as a tumor suppressor and is a negative prognostication marker for survival.


Assuntos
Astrocitoma/genética , Astrocitoma/patologia , Transformação Celular Neoplásica , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Animais , Apoptose , Astrocitoma/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Western Blotting , Encéfalo/metabolismo , Encéfalo/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Adesão Celular , Ciclo Celular , Movimento Celular , Proliferação de Células , Células Cultivadas , Metilação de DNA , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Imunofluorescência , Humanos , Técnicas Imunoenzimáticas , Perda de Heterozigosidade , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Mutação/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida , Proteínas Supressoras de Tumor
15.
Eur J Med Genet ; 53(6): 358-66, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20849990

RESUMO

Agnathia-otocephaly, a rare, sporadic and lethal malformation, is characterized by microstomia (small mouth), aglossia (absence of the tongue), agnathia (absence of the lower jaw) and abnormally positioned ears. It is a principal anomaly derived from the first pharyngeal arch as a consequence of failed mesenchymal migration of the maxillary prominence and atrophy in the development of the mandibular prominences. Unfortunately, these patients have poor prognoses and may succumb to death shortly after birth due to respiratory problems if appropriate airway management is not implemented. Difficulties persist in the prenatal diagnosis of agnathia-otocephalic patients. However, two- and three-dimensional ultrasonography, computed tomography and magnetic resonance imaging technologies now offer significant improvements in refining the resolution of distinctive facial anomalies. This complex disorder can be attributed to both genetic and teratogenic causes, in addition to other unidentifiable factors. Furthermore, studies in model organisms, in particular mice, have unraveled potential genetic pathways that may contribute to the etiology. This article highlights current perspectives on agnathia-otocephaly with a focus on the etiological causes and issues concerning prenatal diagnosis, differential diagnosis, prognosis and genetic counseling. Finally, studies using animal models especially genetically engineered mice are described to comprehend the molecular genetic interactions that may occur during the genesis of this intriguing craniofacial birth defect.


Assuntos
Anormalidades Múltiplas/diagnóstico por imagem , Região Branquial/diagnóstico por imagem , Orelha/diagnóstico por imagem , Face/diagnóstico por imagem , Mandíbula/diagnóstico por imagem , Anormalidades Maxilofaciais/diagnóstico por imagem , Microstomia/diagnóstico por imagem , Diagnóstico Pré-Natal/métodos , Língua/diagnóstico por imagem , Manuseio das Vias Aéreas , Animais , Região Branquial/anormalidades , Orelha/anormalidades , Face/anormalidades , Feminino , Doenças Fetais/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Mandíbula/anormalidades , Camundongos , Camundongos Transgênicos , Gravidez , Síndrome , Tomografia Computadorizada por Raios X , Língua/anormalidades , Ultrassonografia Pré-Natal
16.
Clin Invest Med ; 33(4): E223-33, 2010 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-20691140

RESUMO

PURPOSE: To provide a critical assessment of the clinical translational applications of microRNA (miRNA) genes in medulloblastomas. METHODS: Data were obtained from MEDLINE using Boolean-formatted keyword queries. Top articles were selected for critical analyses - depending on the novelty of findings, qualitative assessment of the citation index and relevance to the diagnosis, prognosis and therapeutic targeting of medulloblastomas. RESULTS: MiRNAs, non-protein-coding RNA molecules, negatively regulate gene expression in a sequence-specific manner during biological processes. In the past few years, miRNA genes have emerged as key regulators of not only molecular events involved in normal brain development and function but also in the molecular pathogenesis of medulloblastomas. In this manner, microRNA genes are identified with functional roles as oncogenes and tumor suppressor genes. At least four miRNAs have proven useful in improving the molecular classification of medulloblastomas, and eight others have shown potential in predicting patients' overall prognosis. Moreover, more than 10 miRNA genes can be potentially utilized in therapies against medulloblastomas, using nine recent methods of targetting miRNAs. CONCLUSION: The quest to identify miRNA genes that are of biological significance in medulloblastomas is on an ongoing venture. Most importantly, these miRNAs have been shown to be of clinical importance for improving the accuracy of diagnosis and prognosis and even developing therapies that can significantly improve patients' overall survival from this deadly disease.


Assuntos
Meduloblastoma/genética , Meduloblastoma/terapia , MicroRNAs/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Meduloblastoma/diagnóstico , Meduloblastoma/metabolismo , MicroRNAs/fisiologia , Terapia de Alvo Molecular , Prognóstico
17.
Fetal Pediatr Pathol ; 29(4): 207-11, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20594144

RESUMO

Otocephaly is a severe and lethal malformation. We report a new case of a fetus with agnathia-otocephaly, presenting only the facial findings but with otherwise normal organs. The fetal karyotype was normal. We examined the fetal DNA for uniparental disomy of chromosomes 3 and 4, since the mother is a carrier of a t(3;4) chromosome, but did not identify any evidence. We were also unable to find mutations or possible associations with candidate otocephalic genes, including OTX2 and PGAP1. These findings suggest that the molecular etiology of agnathia-otocephaly is still unknown with a mutation yet to be identified in humans.


Assuntos
Anormalidades Múltiplas/diagnóstico , Análise Mutacional de DNA , Orelha/anormalidades , Anormalidades Maxilofaciais/diagnóstico , Proteínas de Membrana/genética , Fatores de Transcrição Otx/genética , Monoéster Fosfórico Hidrolases/genética , Anormalidades Múltiplas/genética , Aberrações Cromossômicas , Bandeamento Cromossômico , Evolução Fatal , Feminino , Genótipo , Idade Gestacional , Humanos , Masculino , Anormalidades Maxilofaciais/genética , Mutação , Gravidez , Diagnóstico Pré-Natal , Tomografia Computadorizada por Raios X , Ultrassonografia Pré-Natal , Adulto Jovem
18.
Cancer Res ; 69(12): 5099-107, 2009 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-19509233

RESUMO

Schwannomas, although benign, can be fatal or give rise to significant morbidity due to an unpredictable growth rate. They can reoccur after surgery or radiation, current treatments each with significant inherent risks. These risks are further amplified in neurofibromatosis type 2 (NF2), a germ line predisposition syndrome characterized by multiple schwannomas, underlying the need for biological targeted therapies. Gleevec (STI571, imatinib mesylate), in addition to the bcr-abl oncogene in chronic myelogenous leukemia, inhibits c-kit and platelet-derived growth factor receptor (PDGFR) signaling, thereby expanding its use to several malignant and benign human diseases. In the present study, we show that human sporadic and NF2-associated schwannomas have increased expression along with activation of PDGFR-alpha, PDGFR-beta, and c-kit receptors, compared with normal or traumatic nerve. Using the human NF2-null HEI-193 schwannoma cell line, Gleevec inhibited schwannoma viability, proliferation, and anchorage-independent growth, as well as induced apoptosis in a dose-dependent manner (IC(50) 5-10 micromol/L). These antitumorigenic effects were correlated to inhibition of PDGFR-alpha, PDGFR-beta, and c-kit activation/phosphorylation and major downstream signaling pathways. Lack of robust xenograft or transgenic models of schwannomas prevents extension of these studies in vivo. However, the established long track record and tolerable toxicity of Gleevec already in clinical use and our preclinical data lead us to propose that Gleevec should be evaluated in human schwannomas with shown progressive growth.


Assuntos
Antineoplásicos/farmacologia , Divisão Celular/efeitos dos fármacos , Neurilemoma/metabolismo , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-kit/metabolismo , Pirimidinas/farmacologia , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , Apoptose , Benzamidas , Western Blotting , Ciclo Celular , Linhagem Celular Tumoral , Humanos , Mesilato de Imatinib , Imageamento por Ressonância Magnética , Neurilemoma/patologia , Reação em Cadeia da Polimerase
19.
Clin Invest Med ; 32(2): E166-79, 2009 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-19331806

RESUMO

PURPOSE: To provide a critical assessment of current stem-cell based pre-clinical models of astrocytomas (gliomas). METHODS: Data were archived from MEDLINE using Boolean formatted keyword queries. Top articles were selected for critical analyses depending on the qualitative assessment of the citation index, novelty of the findings, reputation of the research group and relevance to stem-cell based pre-clinical models of astrocytomas. RESULTS: The emergence of stem-cell based pre-clinical models of gliomas offers advantages for cellular transformation studies over other current in-vitro cell cultured based models. Cells utilized in these stem-cell based pre-clinical models are easier to transform, with the induced tumours demonstrating very high molecular and pathological recapitulations of astrocytomas that are derived from humans. These stem-cell based models fall into two categories. In the first, synthetic astrocytes can be differentiated from various stem cell sources such as the nervous system and embryos, and utilized in elegant forward genetic strategies to develop novel astrocytoma pre-clinical models. The second category represents a cancer stem cell pre-clinical model. In this model, glioma stem cells exhibit very high pathological recapitulations of the human tumours, and can be very informative to comprehend the basis of radio-chemoresistance among patients. CONCLUSION: The quest to develop robust pre-clinical models of astrocytomas is on an ongoing basis. The models are of clinical importance for the discovery of effective treatment modalities that can considerably improve the health of patients with this deadly disease.


Assuntos
Astrocitoma , Células-Tronco , Animais , Humanos , Modelos Biológicos
20.
Glia ; 56(4): 457-70, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18205175

RESUMO

Our objective was to determine if murine embryonic stem (ES) cells, which are readily available from repositories, could be developed as a model of gliomagenesis, recognizing the difficulty in obtaining and transforming somatic astrocytes. Using a stringently controlled sequential differentiation procedure on wild type (wt) and p53+/- ES cells, we established GFAP+A2B5-synthetic astrocytes with high efficiency (>90%). The synthetic astrocytes stably express several differentiated astrocyte associated structural proteins and biochemical markers, but lacked expression of differentiated neurons and oligodendrocytes. However, in contrast to somatic differentiated astrocytes, the synthetic astrocytes expressed stem cell markers, with a transcriptome profile similar to astrocytes differentiated from neural stem cells (NSC) and somatic astrocyte cultures established from E13.5-Cortex and P4-hippocampus. In addition, the synthetic astrocytes demonstrated plasticity, with ability to dedifferentiate into neuronal and oligodendrocyte lineages. Intracranial injection of postnatal differentiated somatic astrocytes or synthetic astrocytes of either wt or p53+/- background did not grow tumors, unlike corresponding ES cells that develop teratomas. In contrast, retroviral transduction of either wt or p53+/- synthetic astrocytes and not the postnatal somatic astrocytes, with relevant oncogenes found in human malignant astrocytomas (MDM2, myr-AKT, V12H-RAS), led to intracranial high-grade undifferentiated gliomas. This study demonstrates utilization of readily available ES cells of varying genetic backgrounds to model and further our understanding of gliomagenesis. Large numbers of replenishable derivative synthetic glial lineage cells retain genetic and phenotypic characteristics of progenitor cells and thereby are more amenable to transformation by genetic aberrations involved in gliomagenesis.


Assuntos
Astrócitos/fisiologia , Diferenciação Celular/fisiologia , Células-Tronco Embrionárias/fisiologia , Animais , Animais Recém-Nascidos , Encéfalo/citologia , Encéfalo/embriologia , Diferenciação Celular/efeitos dos fármacos , Linhagem da Célula , Células Cultivadas , Embrião de Mamíferos , Células-Tronco Embrionárias/efeitos dos fármacos , Fator 2 de Crescimento de Fibroblastos/farmacologia , Gangliosídeos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Marcação In Situ das Extremidades Cortadas , Camundongos , Camundongos Knockout , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Transdução Genética/métodos , Proteína Supressora de Tumor p53/deficiência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...