CDH1 promoter hypermethylation and E-cadherin protein expression in infiltrating breast cancer

BACKGROUND: The E-cadherin gene (CDH1) maps, at chromosome 16q22.1, a region often associated with loss of heterozygosity (LOH) in human breast cancer. LOH at this site is thought to lead to loss of function of this tumor suppressor gene and was correlated with decreased disease-free survival, poor prognosis, and metastasis. Differential CpG island methylation in the promoter region of the CDH1 gene might be an alternative way for the loss of expression and function of E-cadherin, leading to loss of tissue integrity, an essential step in tumor progression. METHODS: The aim of our study was to assess, by Methylation-Specific Polymerase Chain Reaction (MSP), the methylation pattern of the CDH1 gene and its possible correlation with the expression of E-cadherin and other standard immunohistochemical parameters (Her-2, ER, PgR, p53, and K-67) in a series of 79 primary breast cancers (71 infiltrating ductal, 5 infiltrating lobular, 1 metaplastic, 1 apocrine, and 1 papillary carcinoma). RESULTS: CDH1 hypermethylation was observed in 72% of the cases including 52/71 ductal, 4/5 lobular carcinomas and 1 apocrine carcinoma. Reduced levels of E-cadherin protein were observed in 85% of our samples. Although not statistically significant, the levels of E-cadherin expression tended to diminish with the CDH1 promoter region methylation. In the group of 71 ductal cancinomas, most of the cases of showing CDH1 hypermethylation also presented reduced levels of expression of ER and PgR proteins, and a possible association was observed between CDH1 methylation and ER expression (p = 0.0301, Fisher's exact test). However, this finding was not considered significant after Bonferroni correction of p-value. CONCLUSION: Our preliminary findings suggested that abnormal CDH1 methylation occurs in high frequencies in infiltrating breast cancers associated with a decrease in E-cadherin expression in a subgroup of cases characterized by loss of expression of other important genes to the mammary carcinogenesis process, probably due to the disruption of the mechanism of maintenance of DNA methylation in tumoral cells

Coliformes em água de abastecimento de lojas fast-food da Região Metropolitana de Recife (PE, Brasil) Coliforms in the water supply of fast-food chains in the Metropolitan Region of Recife, in the state of Pernambuco (Brazil)

A garantia do fornecimento de água potável nos serviços de alimentação é uma questão relevante para a saúde pública. Assim, o objetivo deste estudo foi avaliar a qualidade microbiológica da água destinada ao abastecimento de uma rede de lojas fast-food da cidade de Recife (PE) e Região Metropolitana e comparar os resultados aos padrões estabelecidos pela Portaria nº 518/2004 do Ministério da Saúde. Mensalmente, foi analisada uma amostra proveniente de uma das torneiras da área de manipulação das oito lojas investigadas, perfazendo 96 amostras ao longo de um ano, todas coletadas em duplicata. As análises seguiram a metodologia estabelecida na American Public Health Association (APHA) para realização do ensaio presuntivo utilizando o Teste Presença-Ausência, considerando-se o padrão de potabilidade determinado na legislação pertinente. Os resultados revelaram que 11,46% de todas as amostras apresentaram água contaminada por coliformes totais e 1,04% contaminação por coliformes termotolerantes. Conclui-se, portanto, que a qualidade da água disponível nos estabelecimentos produtores de alimentos estudados encontra-se em estado de alerta, uma vez que o percentual significativo das amostras analisadas mostrava-se impróprio para o consumo humano de acordo com a legislação vigente, a qual preconiza ausência de coliformes totais e termotolerantes.<br>A guaranteed supply of clean drinking water in food outlets is a relevant subject for public health. The scope of this study was to assess the microbiological quality of 96 water samples of a network of fast-food stores in the city of Recife (state of Pernambuco, Brazil) and Metropolitan Area and to compare the results to the standards established by Brazilian Health Ministry decree nº 518/2004. Every month, a double sample from one of the faucets in the food preparation area of the eight stores investigated was analyzed, totaling 96 samples over one year. The analyses followed the established methodology of American Public Health Association (APHA), in order to conduct the Presence-Absence Test, considering the potability standard in pertinent legislation. Results revealed that 11.46% and 1.04% of samples contained water contaminated with total coliforms and thermotolerant coliforms, respectively. The quality of the water in the food establishments studied is thus a health hazard since a significant percentage of samples analyzed were inappropriate for human consumption in accordance with current legislation, which stipulates the absence of total coliforms and thermotolerant coliforms

Identification And Complete Sequencing Of Novel Human Transcripts Through The Use Of Mouse Orthologs And Testis Cdna Sequences

The correct identification of all human genes, and their derived transcripts, has not yet been achieved, and it remains one of the major aims of the worldwide genomics community. Computational programs suggest the existence of 30,000 to 40,000 human genes. However, definitive gene identification can only be achieved by experimental approaches. We used two distinct methodologies, one based on the alignment of mouse orthologous sequences to the human genome, and another based on the construction of a high-quality human testis cDNA library, in an attempt to identify new human transcripts within the human genome sequence. We generated 47 complete human transcript sequences, comprising 27 unannotated and 20 annotated sequences. Eight of these transcripts are variants of previously known genes. These transcripts were characterized according to size, number of exons, and chromosomal localization, and a search for protein domains was undertaken based on their putative open reading frames. 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The contribution of 700,000 ORF sequence tags to the definition of the human transcriptome

Open reading frame expressed sequences tags (ORESTES) differ from conventional ESTs by providing sequence data from the central protein coding portion of transcripts. We generated a total of 696,745 ORESTES sequences from 24 human tissues and used a subset of the data that correspond to a set of 15,095 full-length mRNAs as a means of assessing the efficiency of the strategy and its potential contribution to the definition of the human transcriptome. We estimate that ORESTES sampled over 80% of all highly and moderately expressed, and between 40% and 50% of rarely expressed, human genes. In our most thoroughly sequenced tissue, the breast, the 130,000 ORESTES generated are derived from transcripts from an estimated 70% of all genes expressed in that tissue, with an equally efficient representation of both highly and poorly expressed genes. In this respect, we find that the capacity of the ORESTES strategy both for gene discovery and shotgun transcript sequence generation significantly exceeds that of conventional ESTs. The distribution of ORESTES is such that many human transcripts are now represented by a scaffold of partial sequences distributed along the length of each gene product. The experimental joining of the scaffold components, by reverse transcription–PCR, represents a direct route to transcript finishing that may represent a useful alternative to full-length cDNA cloning

Identification of human chromosome 22 transcribed sequences with ORF expressed sequence tags

Transcribed sequences in the human genome can be identified with confidence only by alignment with sequences derived from cDNAs synthesized from naturally occurring mRNAs. We constructed a set of 250,000 cDNAs that represent partial expressed gene sequences and that are biased toward the central coding regions of the resulting transcripts. They are termed ORF expressed sequence tags (ORESTES). The 250,000 ORESTEs were assembled into 81,429 contigs. of these, 1,181 (1.45%) were found to match sequences in chromosome 22 with at least one ORESTES contig for 162 (65.6%) of the 247 known genes, for 67 (44.6%) of the 150 related genes, and for 45 of the 148 (30.4%) EST-predicted genes on this chromosome. Using a set of stringent criteria to validate our sequences, we identified a further 219 previously unannotated transcribed sequences on chromosome 22. of these, 171 were in fact also defined by EST or full length cDNA sequences available in GenBank but not utilized in the initial annotation of the first human chromosome sequence. Thus despite representing less than 15% of all expressed human sequences in the public databases at the time of the present analysis, ORESTEs sequences defined 48 transcribed sequences on chromosome 22 not defined by other sequences. All of the transcribed sequences defined by ORESTEs coincided with DNA regions predicted as encoding exons by GENSCAN