RESUMEN
Background: Vitamin D derivatives and their receptor (VDR) are immune-response modulators in many diseases including malignancies, metabolic conditions, and infections. We hypothesized that one or more variants of VDR single nucleotide polymorphisms (SNPs) are associated with hepatocellular carcinoma (HCC) in hepatitis C virus (HCV) cirrhotic patients. Materials and Methods: A total of 861 subjects were recruited and classified as spontaneous viral clearance (SVC, n = 127), chronic hepatic cirrhosis (CHC, n = 392), and HCC (n = 342). Standard routine laboratory tests were performed and clinical features noted. All individuals were genotyped for seven SNPs spanning the VDR using real-time PCR. Results: Genotype frequencies of SNPs rs7970376, rs11568820, rs4516035, rs2228570 (Fok1), rs1544410 (Bsm-1), and rs731236 (Taq1), but not rs739837, were variously altered in CHC and HCC compared with SVC, and in HCC compared to CHC (all p < 0.001). The most powerful was rs7970376, which brought an OR (95% CI) of 7.14 (4.64-10.98) for HCC compared to SVC (p = 0.001). The carriage of the AGTAC haplotype of five SNPs were linked to CHC compared to SVC at OR 2.88 [95% CI 1.2-6.9] (p = 0.017) and with HCC compared to CHC at OR 1.54 [95% CI = 1.04-2.27 (p = 0.031). Conclusion: SNPs in VDR may have a potential role in the outcomes of patients with HCV infection. VDR SNPs; rs7970376, rs11568820, rs4516035, rs2228570 (Fok1), rs1544410 (Bsm-1), and rs731236 (Taq1) could be used as molecular markers to predict the risk of HCC.
Asunto(s)
Carcinoma Hepatocelular , Hepatitis C , Neoplasias Hepáticas , Receptores de Calcitriol , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/virología , Estudios de Casos y Controles , Predisposición Genética a la Enfermedad , Genotipo , Hepacivirus , Hepatitis C/genética , Humanos , Cirrosis Hepática/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/virología , Polimorfismo de Nucleótido Simple , Receptores de Calcitriol/genética , Vitamina DRESUMEN
Cypermethrin, a type II synthetic pyrethroid pesticide, is widely used in pest control programmes in agriculture and public health. This study aimed to assess the potential effect of cypermethrin on human spermatozoa and the possible ameliorative effects of vitamins C and E. Semen samples of 20 healthy normozoospermic men were divided into six aliquots at room temperature. The first aliquot served as control not exposed to treatments, and the second was incubated with 20 mm vit. C and 2 mm vit. E where the third one was exposed to 10 µm cypermethrin for 6 h. The other three aliquots were incubated with vit. C, vit. E and both vitamins for 30 min before cypermethrin exposure. Semen aliquots were analysed for sperm motility, sperm viability, hypo-osmotic swelling test and modified alkaline comet assay. The results demonstrated a significant decrease in sperm motion, sperm function and increased sperm DNA damage in the cypermethrin group. Addition of vitamins C and E alone/combined led to significant improvement in sperm motion, sperm function and DNA damage, being maximal with both vitamins together. It is concluded that in vitro cypermethrin can alter sperm function and induce DNA damage in spermatozoa, which is improved after using vitamins C and E.
Asunto(s)
Antioxidantes/farmacología , Ácido Ascórbico/farmacología , Piretrinas/toxicidad , Espermatozoides/efectos de los fármacos , Vitamina E/farmacología , Daño del ADN/efectos de los fármacos , Humanos , Masculino , Preservación de Semen , Motilidad Espermática/efectos de los fármacosRESUMEN
c-Maf is a bZip transcription factor expressed in developmental and cellular differentiation processes. Recently, a c-maf knockout mouse model, showing abnormal lens development, has been reported. In order to study the regulation mechanisms of c-maf gene expression during the differentiation process we have cloned and functionally characterized the rat c-maf (maf-2) gene. The rat c-maf gene is an intronless gene, covering a length of 3.5 kb. Transient transfection analysis of the 5'-flanking region of the c-maf gene using luciferase as the reporter gene shows that Pax6, a master transcription factor for lens development, strongly activates the c-maf promoter construct. Endogenous c-maf is also activated by the Pax6 expression vector. Electrophoresis mobility shift assay and DNase I footprinting analysis show that at least three Pax6-binding sites are located in the 5'-flanking and 5'-non-coding regions of the rat c-maf gene. The c-maf gene was also markedly activated by its own product, c-Maf, through the MARE (Maf recognition element), suggesting that a positive autoregulatory mechanism controls this gene. In situ hybridization histochemical detection of Pax6 and c-Maf in the E14 lens showed that both mRNAs are expressed in the lens equator where lens epithelial cells are differentiating to lens fiber cells. These results suggest that a Pax6/c-Maf transcription factor cascade is working in lens development.
Asunto(s)
Proteínas de Unión al ADN/genética , Proteínas de Homeodominio/metabolismo , Proteínas Proto-Oncogénicas/genética , Animales , Secuencia de Bases , Sitios de Unión , Línea Celular , Clonación Molecular , ADN/química , ADN/genética , ADN/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas del Ojo , Regulación de la Expresión Génica , Genes/genética , Proteínas de Homeodominio/genética , Luciferasas/genética , Luciferasas/metabolismo , Datos de Secuencia Molecular , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box , Regiones Promotoras Genéticas/genética , Unión Proteica , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-maf , Ratas , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Secuencias Reguladoras de Ácidos Nucleicos/genética , Proteínas Represoras , Mapeo Restrictivo , Análisis de Secuencia de ADN , Eliminación de Secuencia , Transcripción Genética , TransfecciónRESUMEN
The Maf family of the transcription factors plays a pivotal role in controlling development and cellular differentiation. To clarify the molecular mechanisms controlling mafB expression, a genomic clone of the mouse mafB gene was isolated and analyzed. RNase protection analysis determined the transcription initiation site at 389 bp upstream from the translation initiation site. The 3' end of the gene is located at 946 bp downstream from the termination codon. The gene lacks intron structure. Sequence analysis showed a TATA-like sequence (5'-GATAAAA-3') and an inverted CCAAT-box (5'-ATTGG-3') in the promoter region. Upstream of these sequences, there are several potential regulatory elements, including two GC-boxes (5'-GGGCGG-3'), and a palindromic sequence (5'-GTCAGCTGAC-3') which contains two Maf recognition elements (MARE, 5'-GCTGAC-3') and an E-box (5'-CAGCTG-3'). Transient transfection analysis with the 5'-flanking region of the mafB gene demonstrated that these elements are important for mafB gene expression. In addition, cotransfection analysis indicated that the MyoD activates the mouse mafB promoter and the gene is positively auto-regulated by its own product.