RESUMEN

PURPOSE: The fusion gene BCR-ABL has an important role to the progression of chronic myeloid leukemia (CML) and several signaling pathways have been characterized as responsible for the terminal blastic phase (BP). However, the initial phase, the chronic phase (CP), is long lasting and there is much yet to be understood about the critical role of BCR-ABL in this phase. This study aims to evaluate transcriptional deregulation in CD34+ hematopoietic cells (CD34+ cells) from patients with untreated newly diagnosed CML compared with CD34+HC from healthy controls. METHODS: Gene expression profiling in CML-CD34 cells and CD34 cells from healthy controls were used for this purpose with emphasis on five main pathways important for enhanced proliferation/survival, enhanced self-renewal and block of myeloid differentiation. RESULTS: We found 835 genes with changed expression levels (fold change ≥ ±2) in CML-CD34 cells compared with CD34 cells. These include genes belonging to PI3K/AKT, WNT/b-catenin, SHH, NOTCH and MAPK signaling pathways. Four of these pathways converge to MYC activation. We also identified five transcripts upregulated in CD34-CML patients named OSBPL9, MEK2, p90RSK, TCF4 and FZD7 that can be potential biomarkers in CD34-CML-CP. CONCLUSION: We show several mRNAs up- or downregulated in CD34-CML during the chronic phase.

Asunto(s)

Biomarcadores de Tumor/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Transducción de Señal/genética , Transcriptoma , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antígenos CD34 , Quinasas MAP Reguladas por Señal Extracelular/genética , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Femenino , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Células Madre Hematopoyéticas/patología , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Masculino , Persona de Mediana Edad , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores Notch/genética , Receptores Notch/metabolismo , Vía de Señalización Wnt/genética , Adulto Joven

RESUMEN

The low number of hematopoietic stem cells (HSC) in umbilical cord blood (UCB) is directly related to increased risk of transplant failure. Effective ex vivo expansion of HSC has been tried for many years, with conflicting results because of the inability to reproduce in vitro HSC proliferation in the same way it occurs in vivo. We compared freshly isolated HSC with their expanded counterparts by microarray analysis and detected activation of the noncanonical Wnt (wingless-type MMTV integration site family) pathway. Study of early alterations during ex vivo UCB-HSC expansion could contribute to improvement of ex vivo expansion systems.

Asunto(s)

Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , Vía de Señalización Wnt/genética , ADP-Ribosil Ciclasa 1/metabolismo , Antígenos CD34/metabolismo , Calibración , Recuento de Células , Proliferación Celular , Humanos , Reproducibilidad de los Resultados

RESUMEN

The association of education, tobacco smoking, alcohol consumption, and interleukin-2 (IL-2 +114 and -384) and -6 (IL-6 -174) DNA polymorphisms with head and neck squamous cell carcinoma (HNSCC) was investigated in a cohort study of 445 subjects. IL-2 and IL-6 genotypes were determined by real-time PCR. Cox regression was used to estimate hazard ratios (HR) and 95 percent confidence intervals (95 percentCI) of disease-specific survival according to anatomical sites of the head and neck. Mean age was 56 years and most patients were males (87.6 percent). Subjects with 5 or more years of schooling had better survival in larynx cancer. Smoking had no effect on HNSCC survival, but alcohol consumption had a statistically significant effect on larynx cancer. IL-2 gene +114 G/T (HR = 0.52; 95 percentCI = 0.15-1.81) and T/T (HR = 0.22; 95 percentCI = 0.02-3.19) genotypes were associated with better survival in hypopharynx cancer. IL-2 +114 G/T was a predictor of poor survival in oral cavity/oropharynx cancer and larynx cancer (HR = 1.32; 95 percentCI = 0.61-2.85). IL-2 -384 G/T was associated with better survival in oral cavity/oropharynx cancer (HR = 0.80; 95 percentCI = 0.45-1.42) and hypopharynx cancer (HR = 0.68; 95 percentCI = 0.21-2.20), but an inverse relationship was observed for larynx cancer. IL-6 -174 G/C was associated with better survival in hypopharynx cancer (HR = 0.68; 95 percentCI = 0.26-1.78) and larynx cancer (HR = 0.93; 95 percentCI = 0.42-2.07), and C/C reduced mortality in larynx cancer. In general, our results are similar to previous reports on the value of education, smoking, alcohol consumption, and IL-2 and IL-6 genetic polymorphisms for the prognosis of HNSCC, but the risks due to these variables are small and estimates imprecise.

Asunto(s)

Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Carcinoma de Células Escamosas/mortalidad , Neoplasias de Cabeza y Cuello/mortalidad , /genética , /genética , Polimorfismo Genético/genética , Consumo de Bebidas Alcohólicas/efectos adversos , Estudios de Cohortes , Carcinoma de Células Escamosas/etiología , Supervivencia sin Enfermedad , Escolaridad , Genotipo , Neoplasias de Cabeza y Cuello/etiología , Pronóstico , Factores de Riesgo , Fumar/efectos adversos

RESUMEN

The association of education, tobacco smoking, alcohol consumption, and interleukin-2 (IL-2 +114 and -384) and -6 (IL-6 -174) DNA polymorphisms with head and neck squamous cell carcinoma (HNSCC) was investigated in a cohort study of 445 subjects. IL-2 and IL-6 genotypes were determined by real-time PCR. Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (95%CI) of disease-specific survival according to anatomical sites of the head and neck. Mean age was 56 years and most patients were males (87.6%). Subjects with 5 or more years of schooling had better survival in larynx cancer. Smoking had no effect on HNSCC survival, but alcohol consumption had a statistically significant effect on larynx cancer. IL-2 gene +114 G/T (HR = 0.52; 95%CI = 0.15-1.81) and T/T (HR = 0.22; 95%CI = 0.02-3.19) genotypes were associated with better survival in hypopharynx cancer. IL-2 +114 G/T was a predictor of poor survival in oral cavity/oropharynx cancer and larynx cancer (HR = 1.32; 95%CI = 0.61-2.85). IL-2 -384 G/T was associated with better survival in oral cavity/oropharynx cancer (HR = 0.80; 95%CI = 0.45-1.42) and hypopharynx cancer (HR = 0.68; 95%CI = 0.21-2.20), but an inverse relationship was observed for larynx cancer. IL-6 -174 G/C was associated with better survival in hypopharynx cancer (HR = 0.68; 95%CI = 0.26-1.78) and larynx cancer (HR = 0.93; 95%CI = 0.42-2.07), and C/C reduced mortality in larynx cancer. In general, our results are similar to previous reports on the value of education, smoking, alcohol consumption, and IL-2 and IL-6 genetic polymorphisms for the prognosis of HNSCC, but the risks due to these variables are small and estimates imprecise.

Asunto(s)

Carcinoma de Células Escamosas/mortalidad , Neoplasias de Cabeza y Cuello/mortalidad , Interleucina-2/genética , Interleucina-6/genética , Polimorfismo Genético/genética , Anciano , Consumo de Bebidas Alcohólicas/efectos adversos , Carcinoma de Células Escamosas/etiología , Estudios de Cohortes , Supervivencia sin Enfermedad , Escolaridad , Femenino , Genotipo , Neoplasias de Cabeza y Cuello/etiología , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Factores de Riesgo , Fumar/efectos adversos , Carcinoma de Células Escamosas de Cabeza y Cuello

RESUMEN

Tumor necrosis factor-related apoptosis-inducing ligand-TNFSF10 (TRAIL), a member of the TNF-α family and a death receptor ligand, was shown to selectively kill tumor cells. Not surprisingly, TRAIL is downregulated in a variety of tumor cells, including BCR-ABL-positive leukemia. Although we know much about the molecular basis of TRAIL-mediated cell killing, the mechanism responsible for TRAIL inhibition in tumors remains elusive because (a) TRAIL can be regulated by retinoic acid (RA); (b) the tumor antigen preferentially expressed antigen of melanoma (PRAME) was shown to inhibit transcription of RA receptor target genes through the polycomb protein, enhancer of zeste homolog 2 (EZH2); and (c) we have found that TRAIL is inversely correlated with BCR-ABL in chronic myeloid leukemia (CML) patients. Thus, we decided to investigate the association of PRAME, EZH2 and TRAIL in BCR-ABL-positive leukemia. Here, we demonstrate that PRAME, but not EZH2, is upregulated in BCR-ABL cells and is associated with the progression of disease in CML patients. There is a positive correlation between PRAME and BCR-ABL and an inverse correlation between PRAME and TRAIL in these patients. Importantly, knocking down PRAME or EZH2 by RNA interference in a BCR-ABL-positive cell line restores TRAIL expression. Moreover, there is an enrichment of EZH2 binding on the promoter region of TRAIL in a CML cell line. This binding is lost after PRAME knockdown. Finally, knocking down PRAME or EZH2, and consequently induction of TRAIL expression, enhances Imatinib sensibility. Taken together, our data reveal a novel regulatory mechanism responsible for lowering TRAIL expression and provide the basis of alternative targets for combined therapeutic strategies for CML.

Asunto(s)

Antígenos de Neoplasias/metabolismo , Proteínas de Unión al ADN/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Factores de Transcripción/metabolismo , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Antígenos de Neoplasias/análisis , Antineoplásicos/uso terapéutico , Benzamidas , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Carcinoma/tratamiento farmacológico , Carcinoma/genética , Carcinoma/metabolismo , Línea Celular , Proteínas de Unión al ADN/análisis , Progresión de la Enfermedad , Proteína Potenciadora del Homólogo Zeste 2 , Proteínas de Fusión bcr-abl/análisis , Proteínas de Fusión bcr-abl/metabolismo , Humanos , Mesilato de Imatinib , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Melanoma/tratamiento farmacológico , Melanoma/genética , Melanoma/metabolismo , Piperazinas/uso terapéutico , Complejo Represivo Polycomb 2 , Regiones Promotoras Genéticas , Pirimidinas/uso terapéutico , Interferencia de ARN , Ligando Inductor de Apoptosis Relacionado con TNF/análisis , Ligando Inductor de Apoptosis Relacionado con TNF/genética , Factores de Transcripción/análisis , Células Tumorales Cultivadas , Regulación hacia Arriba

RESUMEN

AIMS: Annexin A1 (ANXA1) is a soluble cytoplasmic protein, moving to membranes when calcium levels are elevated. ANXA1 has also been shown to move to the nucleus or outside the cells, depending on tyrosine-kinase signalling, thus interfering in cytoskeletal organization and cell differentiation, mostly in inflammatory and neoplastic processes. The aim was to investigate subcellular patterns of immunohistochemical expression of ANXA1 in neoplastic and non-neoplastic samples from patients with laryngeal squamous cell carcinomas (LSCC), to elucidate the role of ANXA1 in laryngeal carcinogenesis. METHODS AND RESULTS: Serial analysis of gene expression experiments detected reduced expression of ANXA1 gene in LSCC compared with the corresponding non-neoplastic margins. Quantitative polymerase chain reaction confirmed ANXA1 low expression in 15 LSCC and eight matched normal samples. Thus, we investigated subcellular patterns of immunohistochemical expression of ANXA1 in 241 paraffin-embedded samples from 95 patients with LSCC. The results showed ANXA1 down-regulation in dysplastic, tumourous and metastatic lesions and provided evidence for the progressive migration of ANXA1 from the nucleus towards the membrane during laryngeal tumorigenesis. CONCLUSIONS: ANXA1 dysregulation was observed early in laryngeal carcinogenesis, in intra-epithelial neoplasms; it was not found related to prognostic parameters, such as nodal metastases.

Asunto(s)

Anexina A1/metabolismo , Carcinoma de Células Escamosas/metabolismo , Neoplasias Laríngeas/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Anexina A1/análisis , Anexina A1/genética , Western Blotting , Carcinoma de Células Escamosas/patología , Femenino , Expresión Génica , Humanos , Inmunohistoquímica , Neoplasias Laríngeas/patología , Masculino , Persona de Mediana Edad

RESUMEN

MicroRNAs (miRNAs) are a class of small endogenous RNAs that play important regulatory roles by targeting mRNAs for cleavage or translational repression. miRNAs act in diverse biological processes including development, cell growth, apoptosis, and hematopoiesis, suggesting their association with cancer. We determined the miRNA expression profile of chronic and acute lymphocytic leukemias (CLL and ALL) using the TaqMan® MicroRNA Assays Human Panel (Applied Biosystems). Pooled leukemia samples were compared to pooled CD19+ samples from healthy individuals (calibrator) by the 2-DD Ct method. Total RNA input was normalized based on the Ct values obtained for hsa-miR-30b. The five most highly expressed miRNAs were miR-128b, miR-204, miR-218, miR-331, and miR-181b-1 in ALL, and miR-331, miR-29a, miR-195, miR-34a, and miR-29c in CLL. To our knowledge, this is the first report associating miR-128b, miR-204 and miR-331 to hematological malignancies. The miR-17-92 cluster was also found to be up-regulated in ALL, as previously reported for some types of lymphomas. The differences observed in gene expression levels were validated for miR-331 and miR-128b in ALL and CD19+ samples. These miRNAs were up-regulated in ALL, in agreement with our initial results. A brief target analysis was performed for miR-331. One of its putative targets, SOCS1, promotes STAT activation, which is a known mediator of cell proliferation and survival, suggesting the possibility of an association between miR-331 and these processes. This initial screening provided information on miRNA differentially expressed in normal and malignant B-cells that could suggest the potential roles of these miRNAs in hematopoiesis and leukemogenesis.

Asunto(s)

Humanos , Leucemia Linfocítica Crónica de Células B/genética , MicroARNs/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Estudios de Casos y Controles

RESUMEN

MicroRNAs (miRNAs) are a class of small endogenous RNAs that play important regulatory roles by targeting mRNAs for cleavage or translational repression. miRNAs act in diverse biological processes including development, cell growth, apoptosis, and hematopoiesis, suggesting their association with cancer. We determined the miRNA expression profile of chronic and acute lymphocytic leukemias (CLL and ALL) using the TaqMan MicroRNA Assays Human Panel (Applied Biosystems). Pooled leukemia samples were compared to pooled CD19+ samples from healthy individuals (calibrator) by the 2-DD Ct method. Total RNA input was normalized based on the Ct values obtained for hsa-miR-30b. The five most highly expressed miRNAs were miR-128b, miR-204, miR-218, miR-331, and miR-181b-1 in ALL, and miR-331, miR-29a, miR-195, miR-34a, and miR-29c in CLL. To our knowledge, this is the first report associating miR-128b, miR-204 and miR-331 to hematological malignancies. The miR-17-92 cluster was also found to be up-regulated in ALL, as previously reported for some types of lymphomas. The differences observed in gene expression levels were validated for miR-331 and miR-128b in ALL and CD19+ samples. These miRNAs were up-regulated in ALL, in agreement with our initial results. A brief target analysis was performed for miR-331. One of its putative targets, SOCS1, promotes STAT activation, which is a known mediator of cell proliferation and survival, suggesting the possibility of an association between miR-331 and these processes. This initial screening provided information on miRNA differentially expressed in normal and malignant B-cells that could suggest the potential roles of these miRNAs in hematopoiesis and leukemogenesis.

Asunto(s)

Leucemia Linfocítica Crónica de Células B/genética , MicroARNs/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Estudios de Casos y Controles , Humanos

RESUMEN

Genomics is expanding the horizons of epidemiology, providing a new dimension for classical epidemiological studies and inspiring the development of large-scale multicenter studies with the statistical power necessary for the assessment of gene-gene and gene-environment interactions in cancer etiology and prognosis. This paper describes the methodology of the Clinical Genome of Cancer Project in São Paulo, Brazil (CGCP), which includes patients with nine types of tumors and controls. Three major epidemiological designs were used to reach specific objectives: cross-sectional studies to examine gene expression, case-control studies to evaluate etiological factors, and follow-up studies to analyze genetic profiles in prognosis. The clinical groups included patients' data in the electronic database through the Internet. Two approaches were used for data quality control: continuous data evaluation and data entry consistency. A total of 1749 cases and 1509 controls were entered into the CGCP database from the first trimester of 2002 to the end of 2004. Continuous evaluation showed that, for all tumors taken together, only 0.5% of the general form fields still included potential inconsistencies by the end of 2004. Regarding data entry consistency, the highest percentage of errors (11.8%) was observed for the follow-up form, followed by 6.7% for the clinical form, 4.0% for the general form, and only 1.1% for the pathology form. Good data quality is required for their transformation into useful information for clinical application and for preventive measures. The use of the Internet for communication among researchers and for data entry is perhaps the most innovative feature of the CGCP. The monitoring of patients' data guaranteed their quality.

Asunto(s)

Bases de Datos Factuales , Estudios Epidemiológicos , Proyecto Genoma Humano , Internet , Neoplasias/genética , Adulto , Brasil , Niño , Humanos

RESUMEN

Genomics is expanding the horizons of epidemiology, providing a new dimension for classical epidemiological studies and inspiring the development of large-scale multicenter studies with the statistical power necessary for the assessment of gene-gene and gene-environment interactions in cancer etiology and prognosis. This paper describes the methodology of the Clinical Genome of Cancer Project in São Paulo, Brazil (CGCP), which includes patients with nine types of tumors and controls. Three major epidemiological designs were used to reach specific objectives: cross-sectional studies to examine gene expression, case-control studies to evaluate etiological factors, and follow-up studies to analyze genetic profiles in prognosis. The clinical groups included patients' data in the electronic database through the Internet. Two approaches were used for data quality control: continuous data evaluation and data entry consistency. A total of 1749 cases and 1509 controls were entered into the CGCP database from the first trimester of 2002 to the end of 2004. Continuous evaluation showed that, for all tumors taken together, only 0.5 percent of the general form fields still included potential inconsistencies by the end of 2004. Regarding data entry consistency, the highest percentage of errors (11.8 percent) was observed for the follow-up form, followed by 6.7 percent for the clinical form, 4.0 percent for the general form, and only 1.1 percent for the pathology form. Good data quality is required for their transformation into useful information for clinical application and for preventive measures. The use of the Internet for communication among researchers and for data entry is perhaps the most innovative feature of the CGCP. The monitoring of patients' data guaranteed their quality.

Asunto(s)

Adulto , Niño , Humanos , Bases de Datos Factuales , Estudios Epidemiológicos , Proyecto Genoma Humano , Internet , Neoplasias/genética , Brasil

RESUMEN

Serial analysis of gene expression (SAGE) technology produces large sets of interesting genes that are difficult to analyze directly. Bioinformatics tools are needed to interpret the functional information in these gene sets. We present an interactive web-based tool, called Gene Class, which allows functional annotation of SAGE data using the Gene Ontology (GO) database. This tool performs searches in the GO database for each SAGE tag, making associations in the selected GO category for a level selected in the hierarchy. This system provides user-friendly data navigation and visualization for mapping SAGE data onto the gene ontology structure. This tool also provides graphical visualization of the percentage of SAGE tags in each GO category, along with confidence intervals and hypothesis testing.

Asunto(s)

Humanos , Animales , Bases de Datos Genéticas , Etiquetas de Secuencia Expresada , Perfilación de la Expresión Génica/métodos , Programas Informáticos , Terminología , Internet , Modelos Estadísticos

RESUMEN

Ala100Thr has been suggested to be a Caucasian genetic marker on the FY*B allele. As the Brazilian population has arisen from miscegenation among Portuguese, Africans, and Indians, this mutation could possibly be found in Euro- and Afro-Brazilians, or in Brazilian Indians. Fifty-three related individuals and a random sample of 100 subjects from the Brazilian population were investigated using the polymerase chain reaction and four restriction fragment length polymorphisms. Confirming the working hypothesis, among the related individuals three Afro-Brazilians (two of them a mother and daughter) and a woman of Amerindian descent had the Ala100Thr mutation on the FY*B allele. Five non-related Euro-Brazilians also carried the mutation. All nine individuals presented the Fy(a-b+) phenotype. We conclude that the Ala100Thr mutation can occur in populations other than Caucasians and that this mutation does not affect Duffy expression on red blood cells. Gene frequencies for this allele in the non-related individuals were in agreement with those of other populations. The Duffy frequencies of two Amerindian tribes were also investigated.

Asunto(s)

Humanos , Masculino , Femenino , Variación Genética , Receptores de Superficie Celular , Mutación/genética , Sistema del Grupo Sanguíneo Duffy/genética , Brasil , Fenotipo , Genotipo , Indio Americano o Nativo de Alaska/genética , Población Negra/genética , Población Blanca/genética , Marcadores Genéticos , Polimorfismo de Longitud del Fragmento de Restricción , Reacción en Cadena de la Polimerasa

RESUMEN

The FCGR3B gene codes for the FcgammaR3b receptor, which occurs in three polymorphic forms representing the human neutrophil antigens (HNA)-1a, HNA-1b, and HNA-1c. The alleles that code for these antigens are FCGR3B*1, FCGR3B*2, and FCGR3B*3, respectively. New variants of these alleles have been recently described. In order to study the frequency of these alleles and the occurrence of variant forms, we sequenced part of the FCGR3B gene in 149 individuals belonging to four distinct Brazilian populations, i.e., 60 Amerindians, 30 Whites of European descent, 30 Afro-Brazilians, and 30 Japanese. The FCGR3B*1 allele showed high frequency among Amerindians (0.850), with the value detected representing the highest frequency described thus far for this allele in population studies. Its frequency was 0.660 in the Japanese population studied, a value equal to that observed in Afro-Brazilians (0.600) and higher than that observed in Whites (0.480). The FCGR3B*3 allele was only found among Afro-Brazilians, where it occurred at a frequency of 0.080, which was lower than the frequency observed among Afro-North Americans (0.207) and Ugandans (0.166). Two variant haplotypes were detected among Amerindians and Afro-Brazilians, occurring in six individuals (four Amerindians and two Afro-Brazilians). The variant haplotype FCGR3B*1 A227G, which occurred in homozygosis in two Amerindians and in heterozygosis in two Afro-Brazilians, is described for the first time in the present report. In general, these data reveal variability in the frequency of alleles of the FCGR3B gene compared to other populations of the same genetic background in other regions of the world.

Asunto(s)

Antígenos CD/genética , Variación Genética , Isoantígenos/genética , Polimorfismo Genético , Receptores de IgG/genética , Alelos , Población Negra , Brasil , Etnicidad , Proteínas Ligadas a GPI , Frecuencia de los Genes , Genética de Población , Genotipo , Haplotipos , Humanos , Indígenas Sudamericanos , Población Blanca

RESUMEN

The spinal muscular atrophies (SMA) or hereditary motor neuronopathies result from the continuous degeneration and death of spinal cord lower motor neurons, leading to progressive muscular weakness and atrophy. We describe a large Brazilian family exhibiting an extremely rare, late-onset, dominant, proximal, and progressive SMA accompanied by very unusual manifestations, such as an abnormal sweating pattern, and gastrointestinal and sexual dysfunctions, suggesting concomitant involvement of the autonomic nervous system. We propose a new disease category for this disorder, 'hereditary motor and autonomic neuronopathy', and attribute the term, 'survival of motor and autonomic neurons 1' (SMAN1) to the respective locus that was mapped to a 14.5 cM region on chromosome 20q13.2-13.3 by genetic linkage analysis and haplotype studies using microsatellite polymorphic markers. This locus lies between markers D20S120 and D20S173 showing a maximum LOD score of 4.6 at D20S171, defining a region with 33 known genes, including several potential candidates. Identifying the SMAN1 gene should not only improve our understanding of the molecular mechanisms underlying lower motor neuron diseases but also help to clarify the relationship between motor and autonomic neurons.

Asunto(s)

Mapeo Cromosómico/métodos , Cromosomas Humanos Par 20/genética , Neuropatía Hereditaria Motora y Sensorial/genética , Femenino , Marcadores Genéticos , Genotipo , Humanos , Masculino , Linaje , Reacción en Cadena de la Polimerasa

RESUMEN

The spinal muscular atrophies (SMA) or hereditary motor neuronopathies result from the continuous degeneration and death of spinal cord lower motor neurons, leading to progressive muscular weakness and atrophy. We describe a large Brazilian family exhibiting an extremely rare, late-onset, dominant, proximal, and progressive SMA accompanied by very unusual manifestations, such as an abnormal sweating pattern, and gastrointestinal and sexual dysfunctions, suggesting concomitant involvement of the autonomic nervous system. We propose a new disease category for this disorder, `hereditary motor and autonomic neuronopathy', and attribute the term, `survival of motor and autonomic neurons 1' (SMAN1) to the respective locus that was mapped to a 14.5 cM region on chromosome 20q13.2-13.3 by genetic linkage analysis and haplotype studies using microsatellite polymorphic markers. This locus lies between markers D20S120 and D20S173 showing a maximum LOD score of 4.6 at D20S171, defining a region with 33 known genes, including several potential candidates. Identifying the SMAN1 gene should not only improve our understanding of the molecular mechanisms underlying lower motor neuron diseases but also help to clarify the relationship between motor and autonomic neurons.

Asunto(s)

Humanos , Masculino , Femenino , Mapeo Cromosómico/métodos , /genética , Neuropatía Hereditaria Motora y Sensorial/genética , Marcadores Genéticos , Genotipo , Linaje , Reacción en Cadena de la Polimerasa

RESUMEN

Levels of mtDNA(4977) deletions (DeltamtDNA(4977)) have been found to be lower in tumors than in adjacent non-tumoral tissues. In 87 cancer patients, DeltamtDNA(4977) was detected by multiplex polymerase chain reaction (PCR) amplification in 43 (49%) of the tumors and in 74 (85%) of the samples of non-tumoral tissues that were adjacent to the tumors. DeltamtDNA(4977) deletions were detected in 24% of the breast tumors, 52% of the colorectal tumors, 79% of the gastric tumors, and 40% of the head and neck tumors as compared with 77, 83, 100, and 90% of the adjacent respective non-tumoral tissues at the same DNA template dilution. Based on limiting dilution PCR of 16 tumors and their adjacent non-tumoral tissues, it was found that the amount of DeltamtDNA(4977) was 10- to 100-fold lower in the tumor than in the respective control non-tumoral tissues. Real-time PCR experiments were performed to quantify the number of DeltamtDNA(4977) deletions per cell, by determining the mitochondrial-to-nuclear DNA ratio. In all of the cases of breast, colorectal, gastric, and head and neck cancer the proportion of DeltamtDNA(4977) in tumors was lower than that of the respective non-tumoral tissue. Traces of DeltamtDNA(4977) in tumors were apparently due to contamination of tumor tissue with surrounding non-tumoral tissue, as evidenced by tumor microdissection and in situ PCR techniques, suggesting that tumors are essentially free of this mutation. Although the metabolic effect of DeltamtDNA(4977) may be minimal in normal (non-tumor) tissue, in tissue under stress, such as in tumors, even low levels of DeltamtDNA(4977) deletions may be intolerable.

Asunto(s)

Femenino , Humanos , Eliminación de Secuencia/genética , Mutación/genética , Neoplasias Colorrectales/genética , Neoplasias Gástricas/genética , Neoplasias de la Mama/genética , Neoplasias de Cabeza y Cuello/genética , Estudios de Casos y Controles , ADN Mitocondrial/genética , Reacción en Cadena de la Polimerasa , Células Tumorales Cultivadas

RESUMEN

The Brazilian population has heterogeneous ethnic origins and is unevenly distributed in a country of continental dimensions. In addition to the Portuguese colonists until the end of the World War II Brazil received almost 5 million immigrants who settled mainly in the south and southeast. This features of the Brazilian population have two important consequences for the inherited diseases that are associated with an ethnic background: their frequencies are different in various regions of the country reflecting a variety of ethnic origins and variable degrees of admixtures. There was no report about the molecular basis of hypercholesterolemia in Brazil until our report in 1996 that the Lebanese allele is the most common cause of the disease in our country: 10 out of the 30 families were of Arab origin, and the Lebanese allele was detected in 9 of the 10 unrelated families of Arab origin. In addition, the abnormal gene is associated with the same haplotype at the LDL-R locus in all but one family, suggesting single origin for this mutation. Recently we described seven mutations in exons 4, 7, 12 and 14 and a new mutation in exon 15. In another region of our state, eight mutation already described and seven new mutations were described and interesting no common mutations were find. We can conclude that the complex history and structure of the Brazilian population, which was formed by the contribution of a large number of ethnic components that are in a state of increasing miscegenation, is reflected in the frequency and regional distribution of the more common hereditary diseases.

Asunto(s)

Hiperlipoproteinemia Tipo II/genética , Receptores de LDL/genética , Alelos , Brasil/epidemiología , Codón sin Sentido , Etnicidad , Humanos , Hiperlipoproteinemia Tipo II/etnología , Líbano/etnología

RESUMEN

The study of the HLA variability of Native American populations revealed several alleles specific to one or more of the Latin American indigenous populations. The analysis of Amerindian groups distributed all over the continent might inform about the area of origin and the dispersal of these alleles and shed light on the evolution of this remarkable polymorphism. Moreover, HLA alleles and haplotypes are excellent markers to understand the genetic relationships between populations. For these reasons, we characterized the HLA class II polymorphism in seven South American Amerindian populations and compared the results with those previously reported for other Amerindian groups. The Guarani-Kaiowá (n = 160) and Guarani-Nandeva (n = 87) were from the Brazilian state of Mato Grosso do Sul, the Guarani-M'byá (n = 93) and Kaingang (n = 235) from Paraná state, the Aché (n = 89) from eastern Paraguay, the Quechua (n = 44) from Andean Peru. From Amazonia, a heterogeneous group was analyzed (n = 45). The most frequent alleles and haplotypes are common also in other Amerindian populations. Each HLA-DRB1 allele was typically found in combination with just one DQA1-DQB1 haplotype, most likely as a result of some form of random genetic drift and reduced gene flow from non-Amerindians. The frequency distribution differed significantly among all populations, although differences were less pronounced between the Guarani subgroups. Marker alleles allowed an estimate of European and sub-Saharan African gene flow into these populations: Quechua 23%, Guarani-Nandeva 14%, Kaingang 7%, Guarani-M'byá 4%, Guarani-Kaiowá, Amazonia, and Aché 0%. Interestingly, the DRB1*1413 allele, previously found only among the Guarani-M'byá (frequency 15%), appeared in the Aché (8%). The relationship of the Aché to other Amerindian populations is unclear, and this finding reveals a link with the Guarani. On the basis of genetic distance and the HLA allele/haplotype set, we propose that the Aché are differentiated Tupi-Guarani group, most closely related to the Guarani-M'byá.

Asunto(s)

Variación Genética , Antígenos HLA/genética , Indígenas Sudamericanos/genética , Alelos , Evolución Biológica , Frecuencia de los Genes , Antígenos HLA-DQ/genética , Cadenas alfa de HLA-DQ , Cadenas beta de HLA-DQ , Antígenos HLA-DR/genética , Cadenas HLA-DRB1 , Haplotipos , Humanos , Desequilibrio de Ligamiento , Polimorfismo Genético , América del Sur/etnología

RESUMEN

Studies that consider polymorphisms within the apolipoprotein B (apo B) gene as risk factors for coronary artery disease (CAD) have reported conflicting results. The aim of the present study was to search for associations between two DNA RFLPs (XbaI and EcoRI) of the apo B gene and CAD diagnosed by angiography. In the present study we compared 116 Brazilian patients (92 men) with CAD (CAD+) to 78 control patients (26 men) without ischemia or arterial damage (CAD-). The allele frequencies at the XbaI (X) and EcoRI (E) sites did not differ between groups. The genotype distributions of CAD+ and CAD- patients were different (chi (1) = 6.27, P = 0.012) when assigned to two classes (X-X-/E+E+ and the remaining XbaI/EcoRI genotypes). Multivariate logistic regression analysis showed that individuals with the X-X-/E+E+ genotype presented a 6.1 higher chance of developing CAD than individuals with the other XbaI/EcoRI genotypes, independently of the other risk factors considered (sex, tobacco consumption, total cholesterol, hypertension, and triglycerides). We conclude that the X-X-/E+E genotype may be in linkage disequilibrium with an unknown variation in the apo B gene or with a variation in another gene that affects the risk of CAD.

Asunto(s)

Apolipoproteínas B/genética , Enfermedad Coronaria/genética , Desoxirribonucleasa EcoRI/genética , Desoxirribonucleasas de Localización Especificada Tipo II/genética , Polimorfismo Genético/genética , Adulto , Alelos , Estudios de Casos y Controles , Estudios Transversales , Femenino , Marcadores Genéticos , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Polimorfismo de Longitud del Fragmento de Restricción , Estudios Prospectivos , Factores de Riesgo

RESUMEN

Studies that consider polymorphisms within the apolipoprotein B (apo B) gene as risk factors for coronary artery disease (CAD) have reported conflicting results. The aim of the present study was to search for associations between two DNA RFLPs (XbaI and EcoRI) of the apo B gene and CAD diagnosed by angiography. In the present study we compared 116 Brazilian patients (92 men) with CAD (CAD+) to 78 control patients (26 men) without ischemia or arterial damage (CAD-). The allele frequencies at the XbaI (X) and EcoRI (E) sites did not differ between groups. The genotype distributions of CAD+ and CAD- patients were different (chi²(1) = 6.27, P = 0.012) when assigned to two classes (X-X-/E+E+ and the remaining XbaI/EcoRI genotypes). Multivariate logistic regression analysis showed that individuals with the X-X-/E+E+ genotype presented a 6.1 higher chance of developing CAD than individuals with the other XbaI/EcoRI genotypes, independently of the other risk factors considered (sex, tobacco consumption, total cholesterol, hypertension, and triglycerides). We conclude that the X-X-/E+E genotype may be in linkage disequilibrium with an unknown variation in the apo B gene or with a variation in another gene that affects the risk of CAD

Asunto(s)

Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Apolipoproteínas B , Enfermedad Coronaria , Desoxirribonucleasa EcoRI , Desoxirribonucleasas de Localización Especificada Tipo II , Polimorfismo Genético , Alelos , Estudios de Casos y Controles , Estudios Transversales , Marcadores Genéticos , Genotipo , Análisis Multivariante , Polimorfismo de Longitud del Fragmento de Restricción , Estudios Prospectivos , Factores de Riesgo