CDHI 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.

Structural Basis of Importin-alpha-Mediated Nuclear Transport for Ku70 and Ku80

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

SIRT1 Deacetylase Activity and the Maintenance of Protein Homeostasis in Response to Stress: An Overview

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The Leishmania amazonensis TRF ( TTAGGG repeat-binding factor) homologue binds and co-localizes with telomeres

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The 5S rDNA family evolves through concerted and birth-and-death evolution in fish genomes: an example from freshwater stingrays

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Histology and histochemistry of the ventriculus of Dolichoderus (=Monacis) bispinosus (OLIVIER, 1792) (Hymenoptera : Formicidae)

In this study we histologically and histochemically describe the ventriculus of Dolichoderus bispinosus. The epithelium consists of two basic cell types, highly basophilic generative cells, and digestive cells. The latter present several cytoplasmic vesicles. rich in acidic and neutral polysaccharides, and basic proteins. Also, these. cells exhibit an apocrine secretion pattern. A mass of fibrous material is observed on the surface of the epithelium. Finally, we discuss the results obtained. (c) 2005 Elsevier Ltd. All rights reserved.

Inflammation and apoptosis induced by mastoparan Polybia-MPII on skeletal muscle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cytochemistry of fat body trophocytes and ovaries of workers and queens of Melipona quadrifasciata anthidioides (Hymenoptera: Apidae: Meliponini) during vitellogenesis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Functional characterization and target discovery of glycoside hydrolases from the digestome of the lower termite Coptotermes gestroi

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morphofunctional Alterations in Endocrine Pancreas of Short- and Long-term Dexamethasone-treated Rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genomics and proteomics approaches to the study of cancer-stroma interactions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Neuroglobin and cytoglobin: two new members of globin family

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

cAMP signaling pathway controls glycogen metabolism in Neurospora crassa by regulating the glycogen synthase gene expression and phosphorylation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Differential proteomic analysis of Acidithiobacillus ferrooxidans cells maintained in contact with bornite or chalcopyrite: Proteins involved with the early bacterial response

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Electrochemical genosensors for the detection of Bonamia parasite. Selection of single strand-DNA (ssDNA) probes by simulation of the secondary structure folding

A post-PCR nucleic acid work by comparing experimental data, from electrochemical genosensors, and bioinformatics data, derived from the simulation of the secondary structure folding and prediction of hybridisation reaction, was carried out in order to rationalize the selection of ssDNA probes for the detection of two Bonamia species, B. exitiosa and B. ostreae, parasites of Ostrea edulis.Six ssDNA probes (from 11 to 25 bases in length, 2 thiolated and 4 biotinylated) were selected within different regions of B. ostreae and B. exitiosa PCR amplicons (300 and 304 bases, respectively) with the aim to discriminate between these parasite species. ssDNA amplicons and probes were analyzed separately using the "Mfold Web Server" simulating the secondary structure folding behaviour. The hybridisation of amplicon-probe was predicted by means of "Dinamelt Web Server". The results were evaluated considering the number of hydrogen bonds broken and formed in the simulated folding and hybridisation process, variance in gaps for each sequence and number of available bases. In the experimental part, thermally denatured PCR products were captured at the sensor interface via sandwich hybridisation with surface-tethered probes (thiolated probes) and biotinylated signalling probes. A convergence between analytical signals and simulated results was observed, indicating the possibility to use bioinformatic data for ssDNA probes selection to be incorporated in genosensors. (C) 2011 Elsevier B.V. All rights reserved.