RESUMO
The association between Xeroderma Pigmentosum DNA repair genes (XPA rs1800975, XPC rs2228000, XPD rs1799793 and XPF rs1800067) polymorphisms and myelodysplastic syndrome (MDS) have not been reported. To assess the functional role between these polymorphisms and MDS, we evaluated 189 samples stratified in two groups: 95 bone marrow samples from MDS patients and 94 from healthy elderly volunteers used as controls. Genotypes for all polymorphisms were identified in DNA samples in an allelic discrimination experiment by real-time polymerase chain reaction (qPCR). We also studied the mRNA expression of XPA and XPC genes to evaluate if its polymorphisms were functional in 53 RNAm MDS patients by qPCR methodologies. To the rs2228000 polymorphism, the CT and TT polymorphic genotype were associated with increased odds ratio (OR) of more profound cytopenia (hemoglobin and neutrophils count). To the rs1799793 polymorphism, we found that the GG homozygous wild-type genotype was associated with a decreased chance of developing MDS. We observed low expression of XPA in younger patients, in hypoplastic MDS and patients with abnormal karyotype when presented AG or AA polymorphic genotypes. We also found that there was a statistically significant interaction between the presence of micromegakaryocyte on down regulation of XPC regarding the CT heterozygous genotype of the rs1800975 polymorphism. Our results suggest that new functional polymorphisms of Xeroderma Pigmentosum DNA repair genes in MDS are related to its pathogenesis and prognosis.
Assuntos
Proteínas de Ligação a DNA/genética , Síndromes Mielodisplásicas/genética , Proteína de Xeroderma Pigmentoso Grupo A/genética , Proteína Grupo D do Xeroderma Pigmentoso/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Reparo do DNA/genética , Feminino , Predisposição Genética para Doença/genética , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Some studies show that alterations in DNA repair genes polymorphisms are associated with the pathogenesis and susceptibility of Myelodysplastic Syndrome (MDS). We genotyped 60 MDS patients for six DNA repair gene polymorphisms: BRCA1 rs4793191, BRCA2 rs9567623, RAD51 rs1801320, XRCC5 rs3835, XRCC6 rs2267437 and LIG4 rs1805388. The G/C heterozygote genotype of rs1801320 polymorphism was associated with a decreased chance of developing MDS (p = 0.05). Additionally, the G/G homozygous genotype was associated with the presence of one cytopenia in whole blood. The genotype C/G and CG + GG of the rs2267437 polymorphism was associated with normal karyotype (p = 0.010) and bone marrow cellularity normocellular + hypercellular (p = 0.023). We found that the A/G heterozygous genotype of the rs3835 polymorphism is associated with decreased chance of developing MDS (p < 0.001). These results support the importance of RAD51, XRCC5 and XRCC6 genes polymorphisms in the maintenance of genomic stability promoting a better understanding of the genesis and etiology of MDS.
Assuntos
Reparo do DNA/genética , Síndromes Mielodisplásicas/genética , Idoso , Idoso de 80 Anos ou mais , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/patologia , Fatores de RiscoAssuntos
Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/genética , Predisposição Genética para Doença , Síndromes Mielodisplásicas/genética , Polimorfismo de Nucleotídeo Único , Proteínas Serina-Treonina Quinases/genética , Proteínas Supressoras de Tumor/genética , Idoso , Proteínas Mutadas de Ataxia Telangiectasia , Brasil , Estudos de Casos e Controles , Frequência do Gene , Heterozigoto , HumanosRESUMO
A doença de Chagas é causada pelo parasito intracelular Trypanosoma cruzi e afeta em torno de 17 milhões de pessoas na América Latina. A fase crônica da doença caracteriza-se por baixo nível de parasitemia e alto nível de anticorpos Anti-T. cruzi e o diagnóstico é feito preferencialmente utilizando-se métodos sorológicos, incluindo imunofluorescência indireta (IFI), hemaglutinação indireta (HAI) e imunoensaio enzimático (ELISA). São testes que apresentam alta sensibilidade, mas sofrem de baixa especificidade, e um variável número de indivíduos apresenta testes sorológicos inconclusivos. Nos últimos anos, muitos estudos têm usado a tecnologia da Reação em Cadeia da Polimerase (PCR) para detectar sequências de DNA de T. cruzi em sangue de pacientes chagásicos crônicos. A alta especificidade da PCR tem apontado para sua aplicação como método confirmatório no diagnóstico de pacientes com provas sorológicas inconclusivas. O objetivo desse trabalho foi realizar uma análise comparativa entre a PCR e os métodos convencionais mais utilizados para o diagnóstico - sorologia e xenodiagnóstico, na detecção da infecção por T. cruzi, em indivíduos com doença de Chagas crônica. Sangue de 67 pacientes chagásicos crônicos, ambos os sexos, provenientes do ambulatório de doença de Chagas do Hospital Universitário Walter Cantídio, da Universidade Federal do Ceará, fora, avaliados para T. cruzi, utilizando testes sorológicos (IFI, HAI e ELISA), PCR-Multiplex e xenodiagnóstico...
The intracellular parasiteT. cruziis the causative agent of Chagas disease, which affects 17million people in Latin America. The chronic phase is characterized by low parasitemia andhigh level of Anti-T. cruzi antibodies and the diagnosis is done preferably using serologicalmethods, including indirect immunofluorescence(IIF), indirect hemagglutination (IHA) andELISA. These tests show high sensitivity, and low specificity, and a variable number ofindividuals present inconclusiveserological tests. Nowadays, many studies have used thetechnology of Polymerase Chain Reaction(PCR) to detect DNA sequences ofT. cruziinblood of chronic chagasic patients. The high specificity of the PCR has pointed to its use as aconfirmatory method for diagnosing patients withinconclusive serology.This study aimed tocomparative analysis between PCR and conventional methods commonly used for diagnosis -serology and xenodiagnosis in the detection of infection byT. cruziin individuals withchronic Chagas' disease. Blood of 67 chronic chagasic patients, both sex, from the Chagas'disease clinic at the Hospital Universitário Walter Cantídio, of Universidade Federal doCeará, were tested forT. cruzi, using serological tests (IIF, IHA and ELISA), Multiplex PCRand xenodiagnosis. In addition, Multiplex PCR wasalso evaluated in the waste of triatominebugs from the xenodiagnosis of these same patients. According to the results of serologicaltests, patients were classified into 3 groups: 1.Positive test results (when 2 or 3 results fromthe three serological tests werepositive), 2...