RESUMO
A modified version of the JHH-TOCSY experiment, 'signed COSY', is presented that allows the determination of the sign of residual dipolar 1H-1H coupling constants with respect to the sign of one-bond 1H-X coupling constants in linear three-spin systems X-1H-1H, where X = 13C or 15N. In contrast to the original JHH-TOCSY experiments, the signs of J(HH) couplings may be determined for CH2-CH2 moieties and for uniformly 13C/15N-labelled samples. In addition, sensitivity is enhanced, diagonal peaks are suppressed and cross peaks are observed only between directly coupled protons, as in a COSY spectrum.
Assuntos
Ressonância Magnética Nuclear Biomolecular/métodos , Aprotinina/química , Isótopos de Carbono , Géis/química , Magnetismo , Modelos Químicos , Isótopos de NitrogênioRESUMO
Deregulation of G1-S transition control in cell cycle is one of the important mechanisms in the development of human tumors including astrocytic gliomas. We have previously reported that approximately two-thirds of glioblastomas (GBs) had abnormalities of G1-S transition control either by mutation/homozygous deletion of RB1 or CDKN2A p16INK4A), or amplification of CDK4 (K. Ichimura et al., Oncogene, 13: 1065-1072, 1996). However, abnormalities of G1-S transition control genes may induce p53-dependent apoptosis in cells. Recent investigations suggest that p14ARF is induced in response to abnormal cell cycle entry and results in p53 accumulation by inhibiting MDM2-mediated transactivational silencing and degradation of p53. To investigate the roles of the G1-S transition control system and the p14ARF/MDM2/p53 pathway in the development of astrocytic gliomas, we examined abnormalities of genes involved in these regulatory pathways in a total of 190 primary human astrocytic gliomas of different malignancy grades [136 GBs, 39 anaplastic astrocytomas (AAs) and 15 astrocytomas (As)]. Sixty-seven percent of GBs (91/136) and 21% of AAs (8/39) had abnormalities of the G1-S control system either by mutation/homozygous deletion of RB1, CDKN2A or CDKN2B, or amplification of CDK4. Seventy-six percent of GBs (103 of 136), 72% of AAs (28 of 39), and 67% of As (10 of 15) had deregulated p53 pathway either by mutation of TP53, amplification of MDM2, or homozygous deletion/mutation of p14ARF. When all of the data were combined and compared, 96% of GBs (87 of 91) and 88% of AAs (7 of 8) with abnormal G1-S transition control also had deregulated p53 pathway. Thus, we demonstrate that deregulation of the G1-S transition control system was almost always accompanied by inactivation of the p53 pathway, clearly illustrating the cooperative roles of these two systems in the development/progression of primary human astrocytic gliomas.
Assuntos
Astrocitoma/genética , Neoplasias Encefálicas/genética , Ciclo Celular/genética , Genes p53 , Mutação , Proteínas Nucleares , Proteínas/genética , Proteínas Proto-Oncogênicas/genética , Astrocitoma/patologia , Neoplasias Encefálicas/patologia , Análise Mutacional de DNA , Éxons , Fase G1 , Inativação Gênica , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Proteínas/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-mdm2 , Proto-Oncogenes , Fase S , Deleção de Sequência , Ativação Transcricional , Proteína Supressora de Tumor p14ARF , Proteína Supressora de Tumor p53/metabolismoRESUMO
The genetic abnormality most frequently identified in glioblastomas is loss of alleles on chromosome 10. We have performed a comprehensive study of the PTEN tumor suppressor gene on 10q23, including loss of heterozygosity (LOH) analysis, multiplex PCR, mutation analysis, and reverse transcription PCR (RT-PCR). In total, 151 glioblastomas, 41 anaplastic astrocytomas, 15 astrocytomas, and 13 glioma cell lines were analyzed as well as 23 xenografts derived from primary glioblastomas, which allows a comparison of the PTEN gene status in primary tumors versus xenografts. Homozygous deletions were found in 7% of the glioblastomas and 40% showed mutation of a single retained allele. This mutation frequency is higher than reported previously. The large number of mutations identified allows the presentation of a mutational profile along the coding sequence. The majority of mutations appear to affect conserved residues or structurally conserved regions. PTEN alterations were selected for in xenografts, and there is evidence that they may even facilitate establishment of xenografts. No alterations were found in astrocytomas and only 5% of anaplastic astrocytomas had mutations. Thus, loss of wild type PTEN represents one of the major abnormalities associated with astrocytic tumor progression to glioblastoma and provides a strong selective growth advantage when cultivating glioblastoma tissue in xenografts. No correlation with EGFR amplification was evident.
Assuntos
Neoplasias Encefálicas/genética , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor/genética , Glioblastoma/genética , Monoéster Fosfórico Hidrolases/genética , Proteínas Supressoras de Tumor , Alelos , Processamento Alternativo/genética , Animais , Neoplasias Encefálicas/patologia , Análise Mutacional de DNA , Primers do DNA , DNA de Neoplasias/análise , DNA Satélite/análise , Receptores ErbB/genética , Mutação da Fase de Leitura , Deleção de Genes , Glioblastoma/patologia , Homozigoto , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Mutação de Sentido Incorreto , Transplante de Neoplasias , PTEN Fosfo-Hidrolase , Polimorfismo Genético , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Transplante Heterólogo , Células Tumorais CultivadasRESUMO
Hydatid cyst is a parasitic disease caused by Taenia echinococcus. The first and most important site for this parasite is the liver. Secondary involvement of the pelvic organs is seen. However, the primary involvement is very rare. Here we are reporting a case with primary involvement of the ovary which underwent laparotomy and was proven by microscopic studies.
