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.

Maternal undernutrition and the offspring kidney: from fetal to adult life

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

IFPA Meeting 2010 Workshop Report I: Immunology; Ion transport; Epigenetics; Vascular reactivity; Epitheliochorial placentation; Proteomics

Workshops are an important part of the IFPA annual meeting. At IFPA Meeting 2010 there were twelve themed workshops, six of which are summarized in this report 1. The immunology workshop focused on normal and pathological functions of the maternal immune system in pregnancy. 2. The transport workshop dealt with regulation of ion and water transport across the syncytiotrophoblast of human placenta. 3. The epigenetics workshop covered DNA methylation and its potential role in regulating gene expression in placental development and disease. 4. The vascular reactivity workshop concentrated on methodological approaches used to study placental vascular function. 5. The workshop on epitheliochorial placentation covered current advances from in vivo and in vitro studies of different domestic species. 6. The proteomics workshop focused on a variety of techniques and procedures necessary for proteomic analysis and how they may be implemented for placental research. (C) 2011 Published by IFPA and Elsevier Ltd.

Immunomodulatory effects of low dose chemotherapy and perspectives of its combination with immunotherapy

Given that cancer is one of the main causes of death worldwide, many efforts have been directed toward discovering new treatments and approaches to cure or control this group of diseases. Chemotherapy is the main treatment for cancer; however, a conventional schedule based on maximum tolerated dose (MTD) shows several side effects and frequently allows the development of drug resistance. On the other side, low dose chemotherapy involves antiangiogenic and immunomodulatory processes that help host to fight against tumor cells, with lower grade of side effects. In this review, we present evidence that metronomic chemotherapy, based on the frequent administration of low or intermediate doses of chemotherapeutics, can be better than or as efficient as MTD. Finally, we present some data indicating that noncytotoxic concentrations of antineoplastic agents are able to both up-regulate the immune system and increase the susceptibility of tumor cells to cytotoxic T lymphocytes. Taken together, data from the literature provides us with sufficient evidence that low concentrations of selected chemotherapeutic agents, rather than conventional high doses, should be evaluated in combination with immunotherapy. Copyright © 2012 UICC.

Phenotypic and metabolic aspects of prostatic epithelial cells in aged gerbils after antisteroidal therapy: Turnover in the state of chromatin condensation and androgen-independent cell replacement

The gerbil is a rodent considered a good model for studies of prostatic morphophysiology under different experimental conditions. Studies involving castration and steroidal blockers of aged gerbils showed that the glandular epithelium persists after long-term therapy, preventing the organ atrophy. Thus, the objective of this study was to evaluate the phenotypic characteristics and behavior of prostatic epithelial cells that remained after different periods of hormone ablation in aged gerbils. The identification of elements that influenced the survival of this cell type was performed by morphometric, nuclear phenotypes, ultrastructural and immune histochemical analysis. The most significant responses to treatment, by analyzing morphometric features, were observed during the first three time points (day 1, day 3, and day 7), after which there appeared to be an adjustment of the gland to the hormone ablation. All treatments led to changes in the state of chromatin condensation, DNA methylation pattern and phenotypic changes indicated cell senescence. Additionally, an increase in the basal cells seemed to guarantee self-renewal properties to the epithelium. These data indicate that changes occur at many levels, including gene expression and nuclear architecture in the epithelial cells, when aging and steroidal blockade are associated. These aspects are important when considering castration-resistant prostate cancer, a malignant tumor posing difficult therapeutic intervention. © 2013 Elsevier GmbH. All rights reserved.

Análise do imprinting e da expressão dos genes H19 e IGF2 em células de Sertoli humanas apos exposição in vitro ao 2,3,7,8-Tetraclorodibenzo-p-dioxina (TCDD)

Pós-graduação em Biologia Geral e Aplicada - IBB

Avaliação do padrão de metilação de regiões promotoras dos genes ESR1, ESR2 e PGR na endometriose profunda intestinal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação do padrão de metilação da DMR (Differentially Methylated Region) dos gnes IGF2 e H19 em carcinomas uroteliais

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

Efeito das condições de cultivo no remodelamento das histonas de embriões bovinos produzidos in vitro

Pós-graduação em Medicina Veterinária - FCAV

Análise das alterações genéticas e epigenéticas dos tumores gástricos infectados por Helicobacter pylori e v rus Epstein-Barr

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Alterações epigenéticas e do número de cópias do gene SFN em carcinomas mamários

Pós-graduação em Ciências Biológicas (Genética) - IBB

Efeito da infecção e da terapia de erradicação da Helicobacter pylori na expressão gênica de paciente com gastrite crônica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Proteomic analysis of banana fruit reveals proteins that are differentially accumulated during ripening

Bananas (Musa spp.) are highly perishable fruit of notable economic and nutritional relevance. Because the identification of proteins involved in metabolic pathways could help to extend green-life and improve the quality of the fruit, this study aimed to compare the proteins of banana pulp at the pre-climacteric and climacteric stages. The use of two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) revealed 50 differentially expressed proteins, and comparing those proteins to the Mass Spectrometry Protein Sequence Database (MSDB) identified 26 known proteins. Chitinases were the most abundant types of proteins in unripe bananas, and two isoforms in the ripe fruit have been implicated in the stress/defense response. In this regard, three heat shock proteins and isoflavone reductase were also abundant at the climacteric stage. Concerning fruit quality, pectate lyase, malate dehydrogenase, and starch phosphorylase accumulated during ripening. In addition to the ethylene formation enzyme amino cyclo carboxylic acid oxidase, the accumulation of S-adenosyl-L-homocysteine hydrolase was needed because of the increased ethylene synthesis and DNA methylation that occurred in ripening bananas. Differential analysis provided information on the ripening-associated changes that occurred in proteins involved in banana flavor, texture, defense, synthesis of ethylene, regulation of expression, and protein folding, and this analysis validated previous data on the transcripts during ripening. In this regard, the differential proteomics of fruit pulp enlarged our understanding of the process of banana ripening. (C) 2012 Elsevier B.V. All rights reserved.

The humankind genome: from genetic diversity to the origin of human diseases

Genome-wide association studies have failed to establish common variant risk for the majority of common human diseases. The underlying reasons for this failure are explained by recent studies of resequencing and comparison of over 1200 human genomes and 10 000 exomes, together with the delineation of DNA methylation patterns (epigenome) and full characterization of coding and noncoding RNAs (transcriptome) being transcribed. These studies have provided the most comprehensive catalogues of functional elements and genetic variants that are now available for global integrative analysis and experimental validation in prospective cohort studies. With these datasets, researchers will have unparalleled opportunities for the alignment, mining, and testing of hypotheses for the roles of specific genetic variants, including copy number variations, single nucleotide polymorphisms, and indels as the cause of specific phenotypes and diseases. Through the use of next-generation sequencing technologies for genotyping and standardized ontological annotation to systematically analyze the effects of genomic variation on humans and model organism phenotypes, we will be able to find candidate genes and new clues for disease’s etiology and treatment. This article describes essential concepts in genetics and genomic technologies as well as the emerging computational framework to comprehensively search websites and platforms available for the analysis and interpretation of genomic data.

Composti perfluorurati: Valutazione degli effetti biologici e molecolari in modelli cellulari

L’acido perfluorottanoico (PFOA) e l’acido perfluoronanoico (PFNA) sono composti perfluorurati (PFCs) comunemente utilizzati nell’industria, negli ultimi 60 anni, per diverse applicazioni. A causa della loro resistenza alla degradazione, questi composti sono in grado di accumularsi nell’ambiente e negli organismi viventi, da cui possono essere assunti in particolare attraverso la dieta. Le esistenti evidenze sugli effetti dell’esposizione negli animali, tra cui la potenziale cancerogenicità, hanno accresciuto l’interesse sui possibili rischi per la salute nell’uomo. Recenti studi sull’uomo indicano che i PFC sono presenti nel siero, con livelli molto alti soprattutto nei lavoratori cronicamente esposti, e sono associati positivamente al cancro al seno e alla prostata. Inoltre, sono state riportate proprietà estrogen-like e variazioni nei livelli di metilazione sui promotori di alcuni geni. L’esposizione in utero è stata associata positivamente a ipometilazione globale del DNA nel siero cordonale. L’obiettivo di questo studio è stato quello di indagare gli effetti dell’esposizione a questi perfluorurati su linee cellulari tumorali e primarie umane (MOLM-13, RPMI, HEPG2, MCF7,WBC, HMEC e MCF12A), appartenenti a diversi tessuti target, utilizzando un ampio range di concentrazioni (3.12 nM - 500 μM). In particolare, si è valutato: la vitalità, il ciclo cellulare, l’espressione genica, la metilazione globale del DNA e la metilazione gene specifica. Dai risultati è emerso come entrambi i perfluorurati abbiano effetti biologici: PFOA presenta un effetto prevalente citostatico, PFNA prevalentemente citotossico. L’effetto è, però, prevalente sulle linee cellulari primarie di epitelio mammario (HMEC, MCF12A), anche a concentrazioni riscontrate in lavoratori cronicamente esposti (≥31,25 µM). Dall’analisi su queste cellule primarie, non risultano variazioni significative della metilazione globale del DNA alle concentrazioni di 15,6 e 31,25 µM. Emergono invece variazioni sui geni marcatori del cancro al seno, del ciclo cellulare, dell’apoptosi, del pathway di PPAR-α e degli estrogeni, ad una concentrazione di 31,25 µM di entrambi i PFCs.