Human glutathione S-transferase polymorphisms associated with prostate cancer in the Brazilian population

Objective To evaluate the influence of polymorphisms in GSTA1, GSTM1, GSTT1, and GSTP1 in the risk of developing Prostate Cancer (PCa) in a population of Rio de Janeiro and compare the distribution of allele and genotype frequencies of the polymorphisms analyzed in the present study population with other regions in the country and different ethnic groups. Materials and Methods We analyzed a sample of the Brazilian population, comprising 196 patients with PCa treated by the urology services of the Brazilian National Cancer Institute (INCA) and Mario Kroeff Hospital (HMK), and 208 male blood donors from the Clementino Fraga Filho Hospital, Federal University of Rio de Janeiro (UFRJ). The polymorphisms were determined in DNA, extracted from peripheral blood leucocytes using the Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP). Results Our results showed that the distribution of polymorphisms can vary significantly according to the Brazilian region and ethnic groups. The distribution of allele and genotype frequencies of the polymorphism GSTA1 was statistically different between cases and controls. Genotypes (A / B + B / B) were associated with protection (OR = 0.61, 95 % CI = 0.40-0.92) for PCa in comparison to genotype A / A. Conclusion The distribution of genotype frequencies of the polymorphism GSTA1 was statistically different between the case and control groups (p = 0.023), and the presence of genotypes A / B and B / B suggests a protective role against the risk of PCa compared to genotype A / A. This is the first study that reports the genotypic frequency of this polymorphism and its association with PCa in a Brazilian population sample. .

Superoxide dismutase, catalase, glutathione peroxidase and gluthatione S-transferases M1 and T1 gene polymorphisms in three Brazilian population groups

Antioxidants such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX1) reduce the oxidation rates in the organism. Gluthatione S-transferases (GSTs) play a vital role in phase 2 of biotransformation of many substances. Variation in the expression of these enzymes suggests individual differences for the degree of antioxidant protection and geographical differences in the distribution of these variants. We described the distribution frequency of CAT (21A/T), SOD2 (Ala9Val), GPX1 (Pro198Leu), GSTM1 and GSTT1 polymorphisms in three Brazilian population groups: Kayabi Amerindians (n = 60), Kalunga Afro-descendants (n = 72), and an urban mixed population from Federal District (n = 162). Frequencies of the variants observed in Kalunga (18 percent to 58 percent) and Federal District (33 percent to 63 percent) were similar to those observed in Euro and Afro-descendants, while in Kayabi (3 percent to 68 percent), depending on the marker, frequencies were similar to the ones found in different ethnic groups. Except for SOD2 in all population groups studied here, and for GPX1 in Kalunga, the genotypic distributions were in accordance with Hardy-Weinberg Equilibrium. These data can clarify the contribution of different ethnicities in the formation of mixed populations, such as that of Brazil. Moreover, outcomes will be valuable resources for future functional studies and for genetic studies in specific populations. If these studies are designed to comprehensively explore the role of these genetic polymorphisms in the etiology of human diseases they may help to prevent inconsistent genotype-phenotype associations in pharmacogenetic studies.

Polimorfismos do gene NRAMP1 em indivíduos com reações hansênicas, atendidos em dois Centros de Referência no Recife, nordeste do Brasil / NRAMP1 gene polymorphisms in individuals with leprosy reactions attended at two reference centers in Recife, northeastern Brazil

INTRODUÇÃO: Para investigar susceptibilidade às reações hansênicas, três polimorfismos do gene natural resistance-associated macrophage protein (NRAMP1), foram determinados em 201 indivíduos, atendidos em dois centros de referência no Recife, entre 2007 e 2008, sendo 100 paucibacilares e 101 multibacilares. MÉTODOS: A determinação dos polimorfismos 274C/T, D543N e 1729+55del4 do gene NRAMP1 foi realizada utilizando a técnica do polimorfismo de fragmento de restrição em DNA extraído de sangue periférico e as estimativas das freqüências alélicas e genotípicas foram feitas por contagem direta. RESULTADOS: Os genótipos predominantes foram: CC (51,8 por cento) para 274C/T, GG (86,6 por cento) para D543N e +-TGTG (59,9 por cento) para 1729+55del4. O genótipo mutante 274 TT predominou na negatividade da reação reversa (p=0,03) e na positividade do eritema nodoso (p=0,04). CONCLUSÕES: Nossos resultados sugerem que o polimorfismo 274 C/T do gene NRAMP1 pode auxiliar na determinação da susceptibilidade à reação tipo II em indivíduos com hanseníase.

INTRODUCTION: To investigate susceptibility to leprosy reactions, three polymorphisms of the natural resistance-associated macrophage protein (NRAMP1) gene were determined in 201 individuals who were attended at two reference centers in Recife, between 2007 and 2008. Of these, 100 were paucibacillary and 101 were multibacillary. METHODS: The 274C/T, D543N and 1729+55del4 polymorphisms of the NRAMP1 gene were determined using the technique of restriction fragment polymorphism on DNA extracted from peripheral blood. Allelic and genotypic frequencies were estimated by direct counting. RESULTS: The predominant genotypes were: CC (51.8 percent) for 274C/T; GG (86.6 percent) for D543N; and +-TGTG (59.9 percent) for 1729+55del4. The mutant genotype 274 TT predominated in negativity of the reverse reaction (p = 0.03) and in positivity of erythema nodosum leprosum (p = 0.04). CONCLUSIONS: Our results suggest that 274 C/T polymorphism of the NRAMP1 gene may aid in determining the susceptibility to type II reactions among leprosy patients.

Exposição a substâncias químicas e câncer: aspectos epidemiológicos, genéticos e moleculares / Exposition to chemical substances and cancer: epidemiological, genetic and molecular aspects

Este trabalho realizou uma revisão sistemática da literatura no período 1999-2007, analisando a associação entre a exposição a substâncias químicas e o desenvolvimento de câncer. A contribuição da exposição a pesticidas nesta associação é abordada como estudo de caso na literatura internacional, e no Brasil em particular. O papel da exposição a substâncias químicas no processo de carcinogênese é revisto a partir dos conhecimentos contemporâneos sobre as interações genético-ambientais e a contribuição dos polimorfismos genéticos envolvidos na metabolização de substâncias xenobióticas. Estas relações são abordadas tanto na perspectiva da Biologia Molecular como da Epidemiologia, através de exemplos de associações observadas na população geral resultantes de exposições ocupacionais e ambientais.

A systematic literature review between 1999-2007 on the association between chemical exposure and cancer was carried out, and it was highlighted the case study of worldwide and Brazilian experiences of pesticides exposure. Current knowledge on the carcinogenesis process and the role of single genetic polymorphisms were addressed, both from a molecular and an epidemiological approach. Some examples of such association were discussed on the occupational and the environmental. (affecting the general population) perspectives.

CYP1A1 and CYP2E1 polymorphism frequencies in a large Brazilian population

The enzymes encoded by the polymorphic genes CYP1A1 and CYP2E1 play an important role in the activation and inactivation of xenobiotics. These enzymes have been associated with xenobiotic-induced diseases, such as cancer, therapeutic failure and adverse effects of drugs. The aim of the present study was to determine the allelic and genotypic frequencies of these polymorphisms in a large, ethnically mixed Brazilian population sample from Rio de Janeiro. Polymorphisms CYP1A1 and CYP2E1 were determined in 870 unrelated individuals by PCR-RFLP analysis in peripheral blood DNA. The observed allelic frequencies were 0.90 for CYP1A1*1A and 0.95 for CYP2E1*1A, in the total sample. The allelic frequency of CYP1A1*2C in "pardos" (0.13) and Brazilian whites (0.11) was higher than in Caucasians (0.05), which may be a result of the Amerindian genetic component, that presents the highest frequency of this allele observed up to now. The genotype distributions for both polymorphisms were in Hardy-Weinberg equilibrium and were statistically different between males and females, and among ethnic groups.

Distribution of glutathione S-transferase GSTM1 and GSTT1 null phenotypes in Brazilian Amerindians

The distribution of glutathione S-transferase (GST) GSTM1 and GSTT1 null phenotype frequencies in two Brazilian Amerindian tribes, the Munduruku tribe from Missão Cururu village (79 individuals) and the Kayabi tribe (41 individuals), was analyzed by polymerase chain reaction (PCR) amplification. The GST null phenotype frequencies for the Munduruku sample were 0 percent for GSTM1 and 27 percent for GSTT1 while for the Kayabi sample the null phenotype frequencies were 27 percent for GSTM1 and 29 percent for GSTT1. This is the first report of the absence of the GSTM1 null phenotype in any ethnic group.

Glutathione S-transferase M1 (GSTM1) polymorphism in two Brazilian populations

A distribuiçäo das freqüências fenotípicas do gene GSTM1 de duas amostras brasileiras, compostas de doadores sanguíneos de ambos os sexos com idade entre 18 e 61 anos, foi estudada. A primeira amostra é composta de 658 indivíduos provenientes do Rio de Janeiro e a segunda de 179 indivíduos de Brasília. Os fenótipos da GSTM1 foram determinados utilizando-se a técnica da reaçäo em cadeia da polimerase e subsequente digestäo com a enzima de restriçäo HaeII. As freqüências observadas para o fenótipo GSTM1 nulo foram de 46,4 por cento e 48,6 por cento para as amostras do Rio de Janeiro e Brasília, respectivamente. Os resultados também mostram que a distribuiçäo fenotípica da GSTM1 näo está em equilíbrio de Hardy-Weinberg para ambas as amostras: X²1 = 11,49 (P < 0,001) para o Rio de Janeiro e X²1 = 6,77 (P < 0,01) para Brasília. Este desequilíbrio pode ser atribuído a fatores como seleçäo, erros na determinaçäo fenotípica ou panmixia ainda incompleta da populaçäo brasileira, cujos componentes raciais säo caucasóides, africanos e índios.

Studies on polymorphism segregation in Northeastern Brazil. I: analysis of multiloci

The population dynamics of several polymorphic systems were studied in two samples originated from Northeastern Brazil. A high frequency of gametic disequilibrium values between loci pairs was observed, which could be explained by the recent history of racial admixture of the population. However, for multiple loci segregation, no significant differences between the expected and observed numbers of homozygotes could be detected, indicating a lack of biological mechanisms acting on these complex genetic structures.