RESUMO
Background: Breast cancer is a multifactorial disease whose genetic susceptibility is related to polymorphic variants of cell proliferation and migration pathways. Variants in AXIN2 and TCF7L2 in the Wnt-ß catenin pathway have been associated with different types of cancer; however, little is known about its role in breast cancer. This study tests the hypothesis of links between AXIN2 rs1133683 and rs2240308, and TCF7L2 rs7903146 and rs12255372 variants in breast cancer. Methods: Peripheral blood samples were obtained from 404 women (202 patients and 202 control females). The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology was used to identify the gene variants. Results: The AXIN2 rs2240308 (C > T), and TCF7L2 rs7903146 (C > T) and rs12255372 (G > T) variants were associated with breast cancer and with age, TNM stage, and histologic-molecular subtype (p = 0.001). Likewise, the haplotype T-T in the TCF7L2 gene (rs7903146-rs12253372) was significantly related with breast cancer (OR = 2.66, 95%, CI = 1.64-4.30, p = 0.001). Conclusion: Our data show a link between AXIN2 rs2240308 and TCF7L2 rs7903146 and rs12255372 variants in breast cancer, and speculate this may be important in pathogenesis.
Assuntos
Proteína Axina , Neoplasias da Mama , Diabetes Mellitus Tipo 2 , Proteína 2 Semelhante ao Fator 7 de Transcrição , Proteína Axina/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/genética , Feminino , Predisposição Genética para Doença , Genótipo , Haplótipos , Humanos , Polimorfismo de Nucleotídeo Único , Proteína 2 Semelhante ao Fator 7 de Transcrição/genéticaRESUMO
Interferon-inducible transmembrane protein 3 (IFITM3) participates in the defense against viral infections. This study identified and compared the frequency of the IFITM3 rs12252 polymorphism in 410 individuals in western Mexico. The western Mexican allelic frequencies (frequency of the "C" allele = 0.18) differ from some American, East Asian and European populations.
Assuntos
Alelos , Etnicidade/genética , Proteínas de Membrana/genética , Polimorfismo de Nucleotídeo Único , Proteínas de Ligação a RNA/genética , Adolescente , Adulto , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Voluntários Saudáveis , Humanos , México , Pessoa de Meia-Idade , Adulto JovemRESUMO
Polymorphisms in the LEP (G-2548A and A19G), LEPR (A326G, A668G and G3057A) and RETN (C-420G and G+62A) genes were documented according to their association with alterations in biochemical parameters such as glucose, insulin and lipid profiles, along with serum leptin and resistin concentrations. The aim of the study was to establish any contribution of the G-2548A and A19G polymorphisms of the LEP gene, the A326G, A668G and G3057A polymorphisms of the LEPR gene, and the C-420G and G+62A polymorphisms of the RETN gene to serum leptin and resistin levels in Mexican young adults. Clinical and biochemical variables, serum leptin and resistin levels, and genotype profiles were analysed in 66 Mexican young adults. Seven polymorphisms in the LEP, LEPR and RETN genes were genotyped using polymerase chain reaction-restriction fragment length polymorphisms analysis. Individuals carrying allele 3057A of the G3057A polymorphism in the LEPR gene showed significantly higher leptin concentrations than those bearing the genotype G/G (43.78 ± 39.11 vs 28.20 ± 14.12 ng/mL; p = 0.021). There were no associations of serum leptin or resistin levels according to the genotype of the other six analysed polymorphisms. Our results suggest that the allele 3057A of the LEPR G3057A polymorphism contributes to increased serum leptin levels in Mexican young adults.
Assuntos
Frequência do Gene , Leptina/genética , Polimorfismo de Nucleotídeo Único , Receptores para Leptina/genética , Resistina/genética , Adolescente , Adulto , Alelos , Distribuição da Gordura Corporal , Peso Corporal , Estudos Transversais , Feminino , Expressão Gênica , Genótipo , Humanos , Leptina/sangue , Masculino , México , Receptores para Leptina/sangue , Resistina/sangue , Estudantes , Circunferência da Cintura/genética , Relação Cintura-QuadrilRESUMO
PPARD encodes for peroxisome proliferator-activated receptor delta, which plays a significant role in controlling lipid metabolism, atherosclerosis, inflammation, cancer growth, progression, and apoptosis. Accumulated evidence suggests that the polymorphism rs2016520 in PPARD is associated with lipid metabolism, obesity, metabolic syndrome, and type 2 diabetes mellitus. The aim of this study was to determine whether the single nucleotide polymorphism +294T/C (rs2016520) in PPARD is associated with colorectal cancer (CRC) in the Mexican population. Genomic DNA from 178 CRC patients and 97 healthy blood donors was analyzed. The polymorphism was identified by the polymerase chain reaction-restriction fragment length polymorphism method. Results demonstrated that patients with the T/C genotype for the +294T/C (rs2016520) polymorphism present a protective role against CRC [odds ratio (OR) = 0.39; 95% confidence interval (CI) = 0.22-0.69; P = 0.0008]. This association was also evident for the T/C genotype in the stratified analysis by tumor-node-metastasis stages I+II (OR = 0.26, P = 0.0332) and III+IV (OR = 0.44, P = 0.0067). However, in the stratified analysis by tumor location, we observed an increased risk of rectal cancer (OR = 7.57, P = 0.0403) vs colon cancer (OR = 4.87, P = 0.234) in patients carrying the C/C genotype and under the dominant and recessive models of inheritance. In conclusion, for the first time, the association between the +294T/C (rs2016520) polymorphism and colorectal cancer has been studied in Mexican patients. Our results reveal that variations in PPARD may play a significant role in genetic susceptibility to colorectal cancer.
Assuntos
Alelos , Neoplasias Colorretais/genética , Predisposição Genética para Doença , PPAR delta/genética , Polimorfismo de Nucleotídeo Único , Estudos de Associação Genética , Genótipo , Humanos , México , Razão de ChancesRESUMO
Accumulative evidence suggests that alterations due to mutations or genetic polymorphisms in the TCF7L2 and CCND1 genes, which are components of the Wnt signaling pathway, contributes to carcinogenesis. The present study was designated to clarify whether common single nucleotide polymorphisms (SNPs) of the transcription factor 7- like 2 (TCF7L2) and cyclin D1 (CCND1) genes are associated with colorectal cancer risk in Mexican patients. A case-control study including 197 colorectal cancer patients and 100 healthy subjects was conducted in a Mexican population. Identification of polymorphisms was made by the polymerase chain reaction-restriction fragment length polymorphism methodology. The association was calculated by the odds ratio (OR) test. The results demonstrate that patients with the T/T genotype for the rs12255372 polymorphism of the TCF7L2 gene present an increased colorectal cancer risk (OR=2.64, P=0.0236). Also, the risk analysis for Tumor-Nodule-Metastasis (TNM) stage and tumor location showed association with this polymorphism under the over-dominant model of inheritance (OR=1.75, P=0.0440). A similar relation was observed for the genotype T/T of the rs7903146 polymorphism and the rectal location of cancer (OR=7.57, P=0.0403). For the rs603965 polymorphism of the CCND1 gene, we observed a protection effect for the colon cancer location under the dominant model (OR=0.49, P=0.0477). These results reveal a significant role of the analyzed polymorphisms in the TCF7L2 and CCND1 genes on the susceptibility or protection for developing colorectal cancer in the Mexican population.
Assuntos
Neoplasias Colorretais/genética , Ciclina D1/genética , Proteína 2 Semelhante ao Fator 7 de Transcrição/genética , Adulto , Alelos , Estudos de Casos e Controles , Neoplasias Colorretais/patologia , Demografia , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Modelos Logísticos , Masculino , México , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Razão de Chances , Polimorfismo de Nucleotídeo ÚnicoRESUMO
The so-called tumor necrosis factor (TNF) block includes the TNFA, lymphotoxin alpha and beta (LTA and LTB) genes with single-nucleotide polymorphisms (SNP) and microsatellites with an allele frequency that exhibits interpopulation variability. To date, no reports have included both SNPs and microsatellites at the TNF block to study Mestizo or Amerindian populations from Mexico. In this study, samples of five Mexican Mestizo populations (Durango, Guadalajara, Monterrey, Puebla, and Tierra Blanca) and four native-Mexican populations (North Lacandonians, South Lacandonians, Tepehuanos, and Yaquis) were genotyped for two SNPs (LTA+252A>G and TNFA-308G>A) and four microsatellites (TNFa, d, e, and f), to analyze the genetic substructure of the Mexican population. Allele and haplotype frequencies, linkage disequilibrium (LD), and interpopulation genetic relationships were calculated. There was significant LD along almost all of the TNF block but the lowest D' values were observed for the TNFf-TNFd pair. Mestizos showed higher allele and haplotype diversity than did natives. The genetic differentiation level was reduced among Mestizos; however, a slightly, but significant genetic substructure was observed between northern and southern Mexican Mestizos. Among the Amerindian populations, the genetic differentiation level was significantly elevated, particularly in both North and South Lacandonians. Furthermore, among Southern Lacandonians, inhabitants of Lacanja town were the most differentiated from all the Mexicans analyzed. The data presented here will serve as a reference for further population and epidemiological studies including these TNF polymorphisms in the Mexican population.
Assuntos
Haplótipos , Indígenas Norte-Americanos/genética , Desequilíbrio de Ligação , Repetições de Microssatélites , Polimorfismo de Nucleotídeo Único , Fator de Necrose Tumoral alfa/genética , Feminino , Humanos , Masculino , MéxicoRESUMO
Persistent infection with human papillomavirus (HPV) has been recognized as the main etiological factor of morbimortality in cervical cancer. Several factors have been associated with the development of cervical disease, but viral load has recently been proposed as an indicator of cervical neoplasia. Therefore, a single measurement of viral load could be a suitable biomarker. We examined HPV viral load as a prognostic biomarker of cervical neoplasia. We used cervical scrapes to determine the total HPV viral load of 46 Mexican patients with various stages of cervical intraepithelial neoplasia (CIN) using hybrid capture assay coupled with a quantitative polymerase chain reaction method for cellularity estimation. Viral load values of CIN2 and CIN3 samples were compared with samples without cervical pathology (WP); all values of viral load were normalized by number of cells analyzed. The analysis showed significant differences in viral load between CIN2 and WP samples (P = 0.01) and between CIN3 and WP samples (P = 0.02). By contrast, no significant difference was detected between viral loads in CIN2 and CIN3 samples. The results showed significant difference between viral loads in CIN2 and CIN3 samples and that in WP samples. HPV viral load was significantly different between patients with CIN2-CIN3 and those with WP and can be used as a predictor of lesions.
Assuntos
Papillomavirus Humano 16/genética , Papillomavirus Humano 18/genética , Infecções por Papillomavirus/virologia , Displasia do Colo do Útero/virologia , Neoplasias do Colo do Útero/virologia , Adolescente , Adulto , Coinfecção/virologia , Estudos Transversais , DNA Viral/genética , Feminino , Humanos , México , Infecções por Papillomavirus/patologia , Prognóstico , Neoplasias do Colo do Útero/patologia , Carga Viral , Adulto Jovem , Displasia do Colo do Útero/patologiaRESUMO
BACKGROUND: The association of the apolipoprotein (Apo E) -epsilon4 allele to neurodegenerative diseases such as Parkinson's disease (PD) has been analyzed in several studies. This association has been identified by amyloid deposits and neurofibrillary tangles in the brains of patients with neurodegenerative diseases. METHOD: In this study the possible relationship between Apo E alleles and PD patients was analyzed in 105 patients with PD and 107 healthy controls from a Mexican population. RESULTS: Allele analysis in PD vs. controls was: epsilon2 in 6% and 2.3%, respectively; epsilon3 in 73% and 88.3%; and epsilon4} in 21% and 9.4%. The epsilon3 allele showed a protective risk effect with an Odds ratio (OR) of 0.36 (95%CI 0.20-0.61) and p < 0.05; contrary results were observed for the epsilon4 allele, which showed an increased risk for PD, with an OR of 2.57(95% CI 1.42-4.79) and p < 0.05. Upon multivariate analysis showed PD risk was evident in patients who were carriers of the genotype epsilon3/epsilon4; age group (fifty or more years) and had exposure to pesticides and solvents (p < 0.05). CONCLUSIONS: The epsilon3/epsilon3}; epsilon3/epsilon4 genotypes of the Apo E, were positively associated with sporadic PD.
Assuntos
Apolipoproteínas E/genética , Doença de Parkinson/genética , Adulto , Alelos , Sequência de Bases , Estudos de Casos e Controles , Primers do DNA , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , México , Pessoa de Meia-Idade , Análise MultivariadaRESUMO
Snyder-Robinson syndrome (SRS, OMIM 309583) is a rare X-linked syndrome characterized by mental retardation, marfanoid habitus, skeletal defects, osteoporosis, and facial asymmetry. Linkage analysis localized the related gene to Xp21.3-p22.12, and a G-to-A transition at point +5 of intron 4 of the spermine synthase gene, which caused truncation of the SMS protein and loss of enzyme activity, was identified in the original family. Here we describe another family with Snyder-Robinson syndrome in two Mexican brothers and a novel mutation (c.496T>G) in the exon 5 of the SMS gene confirming its involvement in this rare X-linked mental retardation syndrome.
Assuntos
Cromossomos Humanos X , Genes Ligados ao Cromossomo X , Deficiência Intelectual Ligada ao Cromossomo X/genética , Mutação de Sentido Incorreto , Espermina Sintase/genética , Adulto , Análise Mutacional de DNA , Éxons , Ligação Genética , Humanos , Deficiência Intelectual/genética , Masculino , Síndrome de Marfan/genética , Osteoporose/genética , Linhagem , Escoliose/genética , Irmãos , Adulto JovemRESUMO
The analysis of polymorphic markers within or closely linked to the cystic fibrosis transmembrane regulator (CFTR) gene is useful as a molecular tool for carrier detection of known and unknown mutations. To establish the association between mutations in the CFTR gene in western Mexican cystic fibrosis (CF) patients, the distribution of XV2c/KM19 haplotypes was analyzed by PCR and restriction enzyme digestion in 384 chromosomes from 74 CF patients, their unaffected parents, and normal subjects. The haplotype analysis revealed that haplotype B was present in 71.9% of CF chromosomes compared to 0% of non-CF chromosomes. The F508del and G542X mutations were strongly associated with haplotype B (96.7% and 100% of chromosomes, respectively). The haplotype distribution of the CF chromosomes carrying other CFTR mutations had a more heterogeneous background. Our results show that haplotype B is associated with CFTR mutations. Therefore, haplotype analysis is a suitable alternate strategy for screening CF patients with a heterogeneous clinical picture from populations with a high molecular heterogeneity where carrier detection programs are not available. In addition, it may be a helpful diagnostic tool for genetic counseling and carrier detection in the relatives of CF patients and in couples who are planning to have children.