RESUMO
More than 75% of the reported mutations in the hereditary breast and ovarian cancer gene, BRCA1, result in truncated proteins. We have used the protein truncation test (PTT) to screen for mutations in exon 11, which encodes 61% of BRCA1. In 45 patients from breast and/or ovarian cancer families we found six novel mutations: two single nucleotide insertions, three small deletions (1-5 bp) and a nonsense mutation identified two unrelated families. Furthermore, we were able to amplify the remaining coding region by RT-PCR using lymphocyte RNA. Combined with PTT, we detected aberrantly spliced products affecting exons 5 and 6 in one of two BRCA1-linked families examined. The protein truncation test promises to become a valuable technique in detecting BRCA1 mutations.
Assuntos
Neoplasias da Mama/genética , Mutação , Proteínas de Neoplasias/genética , Neoplasias Ovarianas/genética , Fatores de Transcrição/genética , Proteína BRCA1 , DNA/análise , Análise Mutacional de DNA , Éxons , Feminino , Ligação Genética , Haplótipos , Humanos , Pessoa de Meia-Idade , Conformação Proteica , Splicing de RNARESUMO
Long-term therapy of nandrolone (N) is recommended to increase mineral density and muscle strength. Using a parenteral sustained release drug formulation with nandrolone decanoate (ND), therapeutic N levels can be achieved and maintained. Until now, it is unknown if hydrolysis of ND into N occurs in tissue at the injection site or after systemic absorption. Therefore, hydrolysis studies were conducted to investigate the location and rate of ND hydrolysis after its release from the oil depot. ND hydrolysis was studied in porcine tissues, to mimic the human muscular and subcutaneous tissues. Additionally, the ND hydrolysis was studied in human whole blood, plasma and serum at a concentration range of 23.3-233.3µM. ND hydrolysis only occurred in human whole blood. The hydrolysis did not start immediately, but after a lag time. The mean lag time for all studied concentrations was 34.9±2.5min. Because of a slow penetration into tissue, hydrolysis of ND is found to be very low in surrounding tissue. Therefore the local generation of the active compound is clinically irrelevant. It is argued that after injection of the oil depot, ND molecules will be transported via the lymphatic system towards lymph nodes. From here, it will enter the central circulation and within half an hour it will hydrolyse to the active N compound.
Assuntos
Nandrolona/análogos & derivados , Anabolizantes/administração & dosagem , Anabolizantes/sangue , Anabolizantes/farmacocinética , Animais , Líquidos Corporais/metabolismo , Bovinos , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Humanos , Hidrólise , Músculo Esquelético/metabolismo , Nandrolona/administração & dosagem , Nandrolona/sangue , Nandrolona/farmacocinética , Decanoato de Nandrolona , SuínosRESUMO
Within one X-linked muscular dystrophy family, different phenotypes for three males occurred: (1) a severely affected Becker patient with cardiomyopathy, (2) a mildly affected Becker patient, and (3) an apparently healthy male with elevated serum CK levels. In the muscle biopsy specimen of patient2 one out of four antibodies (NCL-DYS1) showed absence of dystrophin. The protein truncation test detected a truncated dystrophin for both muscle tissue and lymphocytes of this patient next to an additional near normal size fragment in muscle. Genomic sequence analysis revealed a nonsense mutation in exon 29 (4148C > T) of the dystrophin gene. Sequence analysis of the mRNA fragment of the larger peptide showed skipping of exon 29, restoring an open reading frame. Consequently, the epitope of the antibody NCL-DYS1 is mapped to exon 29. The variable clinical features of the three relatives from healthy to severely affected therefore seems to be related to the level of skipping of exon 29. This finding underscores the future potential of gene therapeutic strategies aimed at inducing exon skipping in Duchenne muscular dystrophy, to generate a much milder disease.
Assuntos
Códon sem Sentido/genética , Distrofina/genética , Éxons/genética , Distrofias Musculares/genética , Fenótipo , Adulto , Biópsia , Análise Mutacional de DNA , Distrofina/metabolismo , Elementos Facilitadores Genéticos , Feminino , Variação Genética/fisiologia , Humanos , Técnicas Imunoenzimáticas , Linfócitos/fisiologia , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/citologia , Músculo Esquelético/fisiologia , Linhagem , Splicing de RNARESUMO
The value of high-dose therapy with autologous stem cell transplantation as first-line therapy in poor prognosis Hodgkin's disease is controversial and we report the results of evaluation of twenty-six patients who were selected for this procedure from February 1989 to July 1994. They were all patients with stage IV at diagnosis with at least two other unfavourable characteristics, i.e. B symptoms, mediastinal mass greater than 0.45 of the thoracic diameter, two or more extranodal sites, bone marrow involvement, inguinal node involvement, serum lactic dehydrogenase greater than 400 IU/L, or low hematocrit. At the time of transplantation, 19 patients were in complete remission and 10 were in partial remission > or = 50%. Procedure-related mortality in the first 90 days post-graft was 7% overall. Of the 24 evaluable patients, 22 (92%) were assessed as complete responders, and 2 (8%) had progression of disease at 6 months. The actuarial overall survival (OS), disease-free survival (DFS) and event-free survival (EFS) at 5 years were 69%, 79% and 58%, respectively. The Cox proportional hazards model was used to assess prognostic factors. In univariate analysis only one prognostic factor was found to be significantly associated with improved DFS, i.e. low serum lactic dehydrogenase (LDH) (DFS at 5 years: 92% if LDH < 400 IU/L vs 44% if LDH 400 IU/L, P = 0.007). DFS rates between first complete remission and first partial remission groups were not significantly different (DFS at 5 years: 87% vs 66%, p = 0.15). These first results are encouraging but randomized studies are needed.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Doença de Hodgkin/terapia , Avaliação de Resultados em Cuidados de Saúde , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bleomicina/uso terapêutico , Intervalo Livre de Doença , Doxorrubicina/uso terapêutico , Etoposídeo/uso terapêutico , Feminino , Humanos , Ifosfamida/uso terapêutico , Masculino , Mecloretamina/uso terapêutico , Pessoa de Meia-Idade , Mitoguazona/uso terapêutico , Prednisolona/uso terapêutico , Prednisona/uso terapêutico , Procarbazina/uso terapêutico , Prognóstico , Estudos Prospectivos , Vimblastina/análogos & derivados , Vimblastina/uso terapêutico , Vincristina/uso terapêuticoAssuntos
Mutagênese Sítio-Dirigida , Repetições de Trinucleotídeos , Clonagem Molecular , Códon , DNA Recombinante/genética , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Escherichia coli/metabolismo , Marcação de Genes/métodos , Código Genético , Glutamina , Oligodesoxirribonucleotídeos/síntese química , Oligodesoxirribonucleotídeos/genética , Especificidade por SubstratoRESUMO
To reduce the level of stray light in a new-generation externally occulted space coronagraph, we consider new concepts for its external occulter and its associated diaphragm and report extended measurements of their light-rejection properties. The experimental setup, which includes an artificial Sun, uses both photometric and CCD imaging techniques and permits the study of the sensitivity to misalignement of the instrument's performance. Conic occulters that have either a multithreaded or a polished surface are found to give performances superior to those of the classical three-disk system and further are highly tolerant to misalignement. Serrated diaphragms outperform circular ones, as the bulk of the diffracted light is diverted from the coronagraphic objective.
RESUMO
BACKGROUND: Serum CA125 (sCA125) was recently reported to be of clinical value in the staging and follow-up of patients with non-Hodgkin's lymphoma (NHL). This report aims to investigate the prognostic value of a new serologic index combining sCA125 and LDH serum levels. PATIENTS AND METHODS: One hundred thirty-seven patients were studied, sixty-three with histologically proven low-grade NHL, and seventy-four with a high-grade subtype. RESULTS: sCA125 and LDH levels were elevated in more than one third of patients. sCA125 was more frequently increased than LDH in low-grade NHL. In this group, complete remission (CR) was achieved in 87, 45, and 0% (P = <2 x 10(-6)) of patients with normal sCA125 and LDH serum levels (Low-risk group), one parameter increased (Intermediate-risk group), and increased sCA125 and LDH serum levels (high-risk group), respectively. The estimated five-year overall survival was 97%, 67% and 22% for low, intermediate, and high-risk groups, respectively. This combination was the only parameter predictive of RFS and OS in multivariate analysis (P < 0.0001). CONCLUSIONS: In this study the combination of s-LDH and sCA125 levels (normal vs. abnormal) was found to be an important prognostic factor in low-grade lymphoma and may be used in the selection of appropriate therapeutic approaches for individual patients.
Assuntos
Biomarcadores Tumorais/sangue , Antígeno Ca-125/sangue , L-Lactato Desidrogenase/sangue , Linfoma não Hodgkin/sangue , Proteínas de Neoplasias/sangue , Índice de Gravidade de Doença , Adulto , Idoso , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Tábuas de Vida , Linfoma não Hodgkin/mortalidade , Linfoma não Hodgkin/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Indução de Remissão , Análise de Sobrevida , Resultado do Tratamento , Microglobulina beta-2/análiseRESUMO
To facilitate the scanning of large genomic regions for the presence of exonic gene segments we have constructed a cosmid-based exon trap vector. The vector serves a dual purpose since it is also suitable for contig construction and physical mapping. The exon trap cassette of vector sCOGH1 consists of the human growth hormone gene driven by the mouse mettallothionein-1 promoter. Inserts are cloned in the multicloning site located in intron 2 of the hGH gene. The efficiency of the system is demonstrated with cosmids containing multiple exons of the Duchenne Muscular Dystrophy gene. All exons present in the inserts were successfully retrieved and no cryptic products were detected. Up to seven exons were isolated simultaneously in a single spliced product. The system has been extended by a transcription-translation-test protocol to determine the presence of large open reading frames in the trapped products, using a combination of tailed PCR primers directing protein synthesis in three different reading frames, followed by in vitro transcription-translation. Having larger stretches of coding sequence in a single exon trap product rather than small single exons greatly facilitates further analysis of potential genes and offers new possibilities for direct mutation analysis of exon trap material.
Assuntos
Cosmídeos , Éxons , Técnicas Genéticas , Genoma , Animais , Sequência de Bases , Mapeamento Cromossômico , Clonagem Molecular , Sondas de DNA/genética , Vetores Genéticos , Hormônio do Crescimento/genética , Humanos , Técnicas In Vitro , Metalotioneína/genética , Camundongos , Dados de Sequência Molecular , Distrofias Musculares/genética , Fases de Leitura Aberta , Reação em Cadeia da Polimerase , Regiões Promotoras GenéticasRESUMO
Hematopoietic reconstitution has been studied in 180 patients after autologous bone marrow transplantation based on peripheral blood cell (PBC) recovery time and marrow progenitor counts sequentially tested for up to 4 years. Several factors that could influence hematopoietic reconstitution have been analyzed including sex, age, diagnosis, disease status, conditioning regimen, graft progenitor content, graft in vitro purging, and postgrafting administration of growth factors. Before transplantation, marrow progenitor values were normal only for colony-forming unit granulocyte macrophage (CFU-GM) in contrast to colony-forming unit-erythroid (CFU-E), burst-forming unit-erythroid (BFU-E), and colony-forming unit-megakaryocyte (CFU-Meg). After transplantation, as described with allogenic grafts, these values remained low for several years, although PBC counts were nearly normalized within a few weeks. Pregraft values were reached after 2 years for CFU-GM and BFU-E, and after 4 years for CFU-E, while CFU-Meg failed to reach pregraft values after this time. Normal levels were reached after 4 years only by CFU-GM. On univariate and multivariate analysis, the following factors appeared to delay both PBC and marrow progenitor reconstitution: underlying disease (particularly acute myeloid leukemias), graft characteristics such as low stem cell content and in vitro purging, conditioning regimens with total body irradiation or busulfan, and lack of postgraft administration of growth factors. In conclusion, high-dose therapy followed by bone marrow transplantation induces a deep and prolonged impairment of hematopoiesis irrespective of any alloimmune reaction or postgraft immunosuppressive therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Transplante de Medula Óssea , Medula Óssea/efeitos dos fármacos , Hematopoese/efeitos dos fármacos , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Medula Óssea/patologia , Medula Óssea/efeitos da radiação , Bussulfano/administração & dosagem , Bussulfano/efeitos adversos , Carmustina/administração & dosagem , Contagem de Células , Criança , Pré-Escolar , Cisplatino/administração & dosagem , Terapia Combinada , Ciclofosfamida/administração & dosagem , Citarabina/administração & dosagem , Etoposídeo/administração & dosagem , Feminino , Seguimentos , Fatores de Crescimento de Células Hematopoéticas/uso terapêutico , Humanos , Masculino , Melfalan/administração & dosagem , Metotrexato/administração & dosagem , Pessoa de Meia-Idade , Mitoxantrona/administração & dosagem , Análise Multivariada , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Neoplasias/radioterapia , Neoplasias/terapia , Prognóstico , Lesões por Radiação/fisiopatologia , Resultado do Tratamento , Vincristina/administração & dosagem , Irradiação Corporal Total/efeitos adversosRESUMO
We have used an RNA based mutation detection method to screen the total coding region of the dystrophin gene of a Duchenne and a Becker muscular dystrophy patient in whom DNA based mutation detection methods have so far failed to detect mutations. By RT-PCR and the protein truncation test (PTT) we could identify point mutations in both cases. DMD patient DL184.3 has a T-->A mutation in intron 59 at position -9, creating a novel splice acceptor site for exon 60. As a result seven intronic bases are spliced into the mRNA, causing a frameshift and premature translation termination 20 codons downstream. Since this patient had died and only fibroblasts were available, we applied MyoD induced myodifferentiation of stored fibroblasts to enhance muscle specific gene expression. With the results of this mutation analysis, prenatal diagnosis could subsequently be performed in this family. BMD patient BL207.1 carries a G-->C mutation at position +5 of intron 64, disrupting the splice donor consensus sequence and activating a cryptic splice donor site 57bp downstream. The inclusion of these 57 intronic bases in the mRNA leaves the reading frame open and results in the insertion of 19 amino acids into the cysteine rich domain of dystrophin. Interestingly, this insertion in a part of the dystrophin considered to interact with the dystrophin binding complex of the sarcolemma is apparently compatible with mild BMD-like clinical features. Both mutations reported are missed by analysis of multiplex PCR products designed for deletion screening of the coding region. Extrapolation from existing point mutation detection efficiencies by DNA and RNA based methods emphasises that RNA based methods are more sensitive and that most of the remaining undetected mutations may affect splice or branch sites or create cryptic splice sites.
Assuntos
Distrofina/genética , Distrofias Musculares/genética , Mutação , Reação em Cadeia da Polimerase/métodos , Adolescente , Sequência de Aminoácidos , Sequência de Bases , Western Blotting , Diferenciação Celular/genética , Criança , Cisteína/química , Cisteína/genética , Elementos de DNA Transponíveis , Distrofina/química , Feminino , Fibroblastos/citologia , Heterozigoto , Humanos , Masculino , Dados de Sequência Molecular , Distrofias Musculares/diagnóstico , Proteína MyoD/genética , Linhagem , Gravidez , Diagnóstico Pré-Natal , Splicing de RNA , TransfecçãoRESUMO
Huntington's disease (HD) is a neurodegenerative disorder with a midlife onset. The disease is caused by expansion of a CAG (glutamine) repeat within the coding region of the HD gene. The molecular mechanism by which the mutated protein causes this disease is still unclear. To study the protein we have generated a set of rabbit polyclonal antibodies raised against different segments of the N-terminal, central and C-terminal parts of the protein. The polyclonal antibodies were affinity purified and characterized in ELISA and Western blotting experiments. All antibodies can react with mouse and human proteins. The specificity of these antibodies is underscored by their recognition of huntingtin with different repeat sizes in extracts prepared from patient-derived lymphoblasts. The antibodies were used in immunofluorescence experiments to study the subcellular localization of huntingtin in mouse neuroblastoma NIE-115 cells. The results indicate that most huntingtin is present in the cytoplasm, whereas a minor fraction is present in the nucleus. On differentiation of the NIE-115 cells in vitro, the subcellular distribution of huntingtin does not change significantly. These results suggest that full-length huntingtin with a normal repeat length can be detected in the nucleus of cycling and non-cycling cultured mammalian cells of neuronal origin. However, in HD autopsy brain the huntingtin-containing neuronal intranuclear inclusions can be detected only with antibodies raised against the N-terminus of huntingtin. Thus several forms of huntingtin display the propensity for nuclear localization, possibly with different functional consequences.
Assuntos
Encéfalo/patologia , Doença de Huntington/patologia , Proteínas do Tecido Nervoso/análise , Neurônios/patologia , Proteínas Nucleares/análise , Animais , Anticorpos , Diferenciação Celular , Humanos , Proteína Huntingtina , Doença de Huntington/genética , Camundongos , Proteínas do Tecido Nervoso/genética , Neuroblastoma , Neurônios/citologia , Proteínas Nucleares/genética , Coelhos , Proteínas Recombinantes de Fusão/análise , Frações Subcelulares/metabolismo , Frações Subcelulares/patologia , Transfecção , Células Tumorais CultivadasRESUMO
Due to frame-shifting mutations in the DMD gene that cause dystrophin deficiency, Duchenne muscular dystrophy (DMD) patients suffer from lethal muscle degeneration. In contrast, mutations in the allelic Becker muscular dystrophy (BMD) do not disrupt the translational reading frame, resulting in a less severe phenotype. In this study, we explored a genetic therapy aimed at restoring the reading frame in muscle cells from DMD patients through targeted modulation of dystrophin pre-mRNA splicing. Considering that exon 45 is the single most frequently deleted exon in DMD, whereas exon (45+46) deletions cause only a mild form of BMD, we set up an antisense-based system to induce exon 46 skipping from the transcript in cultured myotubes of both mouse and human origin. In myotube cultures from two unrelated DMD patients carrying an exon 45 deletion, the induced skipping of exon 46 in only approximately 15% of the mRNA led to normal amounts of properly localized dystrophin in at least 75% of myotubes. Our results provide first evidence of highly effective restoration of dystrophin expression from the endogenous gene in DMD patient-derived muscle cells. This strategy may be applicable to not only >65% of DMD mutations, but also many other genetic diseases.
Assuntos
Distrofina/biossíntese , Distrofina/genética , Éxons , Deleção de Genes , Músculos/citologia , Distrofia Muscular de Duchenne/genética , Oligonucleotídeos Antissenso , Alelos , Animais , Sequência de Bases , Linhagem Celular , Humanos , Imuno-Histoquímica , Camundongos , Microscopia de Fluorescência , Modelos Genéticos , Dados de Sequência Molecular , Músculos/patologia , Oligonucleotídeos Antissenso/farmacologia , Fenótipo , Biossíntese de Proteínas , RNA/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Fatores de Tempo , TransfecçãoRESUMO
As small molecule drugs for Duchenne muscular dystrophy (DMD), antisense oligonucleotides (AONs) have been shown to restore the disrupted reading frame of DMD transcripts by inducing specific exon skipping. This allows the synthesis of largely functional Becker muscular dystrophy (BMD)-like dystrophins and potential conversion of severe DMD into milder BMD phenotypes. Thus far we have used 2'-O-methyl phosphorothioate (2OMePS) AONs. Here, we assessed the skipping efficiencies of different AON analogs containing morpholino-phosphorodiamidate, locked nucleic acid (LNA) or peptide nucleic acid (PNA) backbones. In contrast to PNAs and morpholinos, LNAs have not yet been tested as splice modulators. Compared to the most effective 2OMePS AON directed at exon 46, the LNA induced higher skipping levels in myotubes from a human control (85 versus 20%) and an exon 45 deletion DMD patient (98 versus 75%). The morpholino-induced skipping levels were only 5-6%, whereas the PNA appeared to be ineffective. Further comparative analysis of LNA and 2OMePS AONs containing up to three mismatches revealed that LNAs, while inducing higher skipping efficiencies, show much less sequence specificity. This limitation increases the risk of adverse effects elsewhere in the human genome. Awaiting further improvements in oligochemistry, we thus consider 2OMePS AONs currently the most favorable compounds, at least for targeted DMD exon 46 skipping.