Prevalence of codon 72 P53 polymorphism in Brazilian women with cervix cancer

The p53 codon 72 polymorphism seems to be associated with HPV-carcinogenesis, although controversial data have been reported. A series of Brazilian women with cervix carcinomas were analyzed. Ninety-nine (67%) of 148 women were found to be homozygous (arg/arg) for the arginine polymorphism, and 49 (33%) were heterozygous (arg/pro). This polymorphism may be an important determinant of the risk for cervix cancer, but does not seem to be sufficient for carcinogenesis.Hospital Maternidade Leonor Mendes de Barros Oncologia GinecológicaUniversidade Federal de São Paulo (UNIFESP) Laboratório de Ginecologia MolecularUniversidade Estadual de Campinas Faculdade de Medicina Oncologia GinecológicaUniversidade de São Paulo Departamento de Medicina Social Faculdade de Medicina de Ribeirão PretoIstituto Superiore di Sanità Laboratory of Epidemiology and Biostatistics Cytopathology UnitUNIFESP, Laboratório de Ginecologia MolecularSciEL

Characterization of a genomic signature of pregnancy identified in the breast.

The objective of this study was to comprehensively compare the genomic profiles in the breast of parous and nulliparous postmenopausal women to identify genes that permanently change their expression following pregnancy. The study was designed as a two-phase approach. In the discovery phase, we compared breast genomic profiles of 37 parous with 18 nulliparous postmenopausal women. In the validation phase, confirmation of the genomic patterns observed in the discovery phase was sought in an independent set of 30 parous and 22 nulliparous postmenopausal women. RNA was hybridized to Affymetrix HG_U133 Plus 2.0 oligonucleotide arrays containing probes to 54,675 transcripts, scanned and the images analyzed using Affymetrix GCOS software. Surrogate variable analysis, logistic regression, and significance analysis of microarrays were used to identify statistically significant differences in expression of genes. The false discovery rate (FDR) approach was used to control for multiple comparisons. We found that 208 genes (305 probe sets) were differentially expressed between parous and nulliparous women in both discovery and validation phases of the study at an FDR of 10% and with at least a 1.25-fold change. These genes are involved in regulation of transcription, centrosome organization, RNA splicing, cell-cycle control, adhesion, and differentiation. The results provide initial evidence that full-term pregnancy induces long-term genomic changes in the breast. The genomic signature of pregnancy could be used as an intermediate marker to assess potential chemopreventive interventions with hormones mimicking the effects of pregnancy for prevention of breast cancer

Characterization of a genomic signature of pregnancy identified in the breast.

The objective of this study was to comprehensively compare the genomic profiles in the breast of parous and nulliparous postmenopausal women to identify genes that permanently change their expression following pregnancy. The study was designed as a two-phase approach. In the discovery phase, we compared breast genomic profiles of 37 parous with 18 nulliparous postmenopausal women. In the validation phase, confirmation of the genomic patterns observed in the discovery phase was sought in an independent set of 30 parous and 22 nulliparous postmenopausal women. RNA was hybridized to Affymetrix HG_U133 Plus 2.0 oligonucleotide arrays containing probes to 54,675 transcripts, scanned and the images analyzed using Affymetrix GCOS software. Surrogate variable analysis, logistic regression, and significance analysis of microarrays were used to identify statistically significant differences in expression of genes. The false discovery rate (FDR) approach was used to control for multiple comparisons. We found that 208 genes (305 probe sets) were differentially expressed between parous and nulliparous women in both discovery and validation phases of the study at an FDR of 10% and with at least a 1.25-fold change. These genes are involved in regulation of transcription, centrosome organization, RNA splicing, cell-cycle control, adhesion, and differentiation. The results provide initial evidence that full-term pregnancy induces long-term genomic changes in the breast. The genomic signature of pregnancy could be used as an intermediate marker to assess potential chemopreventive interventions with hormones mimicking the effects of pregnancy for prevention of breast cancer

In utero exposure to butyl benzyl phthalate induces modifications in the morphology and the gene expression profile of the mammary gland: an experimental study in rats

<p>Abstract</p> <p>Background</p> <p>Environmental estrogens are exogenous estrogen-mimicking compounds that can interfere with endogenous endocrine systems. Several of these endocrine disruptors have been shown to alter normal development and influence tumorigenesis in experimental models. N-butyl benzyl phthalate (BBP), a widely used plasticizer, is a well-known endocrine disruptor. The aim of this study was to elucidate the effect of prenatal exposure to BBP on the morphology, proliferative index, and genomic signature of the rat mammary gland at different ages.</p> <p>Methods</p> <p><it>In utero </it>exposure was performed by gavage of pregnant Sprague Dawley CD rats with 120mg or 500mg BBP/kg/day from day 10 post-conception to delivery. Female litters were euthanized at 21, 35, 50 and 100 days. The morphology and proliferative index of the mammary gland were studied from whole mount preparations and BrdU incorporation, respectively. Gene expression profile was assessed by microarrays. Several genes found differentially expressed and related to different functional categories were further validated by real time RT-PCR.</p> <p>Results</p> <p>Prenatal exposure of BBP induced delayed vaginal opening and changes in the post-natal mammary gland long after the end of the treatment, mainly by 35 days of age. Exposure to the high dose resulted in modifications in architecture and proliferative index of the mammary gland, mostly affecting the undifferentiated terminal end buds. Moreover, the expression profiles of this gland in the exposed rats were modified in a dose-dependent fashion. Analysis of functional categories showed that modified genes were related to immune function, cell signaling, proliferation and differentiation, or metabolism.</p> <p>Conclusions</p> <p>Our data suggest that <it>in utero </it>exposure to BBP induced a delayed pubertal onset and modified morphology of the mammary gland. These alterations were accompanied by modifications in gene expression previously associated with an increased susceptibility to carcinogenesis.</p

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) effect on the global gene expression of the rat mammary gland during the development

OBJETIVO: Este estudo teve como objetivo verificar as modificações causadas na proliferação celular e na expressão gênica da glândula mamária de ratas com 21, 35, 50 e 100 dias que foram expostas à 2,3,7,8 tetraclorodibenzo-p-dioxina (TCDD) durante a gestação (tratamento pré-natal) ou durante a lactação (tratamento pré-pubertal). MÉTODOS: Para o tratamento pré-natal, ratas Sprague-Dawley prenhas receberam no 15º dia após a concepção dose única de 3,0µg de TCDD/kg através de gavagem. Para o tratamento pré-pubertal, ratas lactantes receberam no 14º e 17º dias pós-parto 6,67ng ou 20,0ng de TCDD/g. Animais controles receberam volume equivalente de óleo de gergelim. Ao atingiram 21, 35, 50 e 100 dias de idade, as filhotes fêmeas das ratas que receberam TCDD foram sacrificadas e tiveram as glândulas mamárias extraídas para estudo do índice de proliferação celular e expressão gênica. Para o cálculo de índice de proliferação celular, dez ratas por grupo receberam uma injeção intraperitoneal de 200 mg/kg de 5-bromo-2’-deoxiuridina (BrdU) e através de imunohistoquímica foram identificadas as células que estavam proliferando em cada estrutura da glândula mamária. Outras dez ratas por grupo tiveram o RNA da glândula mamária extraído, e este foi utilizado para o estudo de expressão gênica através de microarrays. Para determinar os genes diferencialmente expressos utilizou-se o teste-t bayesiano empírico moderado. Genes diferencialmente expressos (p<0,01) foram então categorizados de acordo com a função biológica ou via canônica de ação. Ainda, genes que se destacaram foram validados através de RT-PCR em tempo real. RESULTADOS: O tratamento pré-pubertal alterou a proliferação celular nas glândulas mamárias das ratas com 35, 50 e 100 dias, principalmente nos botões terminais (TEBs). A análise da expressão gênica demonstrou que o número máximo de genes diferencialmente expressos foi observado nos animais com 100 dias que receberam TCDD durante a gestação. No tratamento pré-pubertal, observou-se que a alta dose causou mais alterações do que a dose baixa. Cyp1b1 foi o gene que mais sofreu aumento de expressão em diferentes idades. A categorização dos genes desregulados de acordo com a função biológica mostrou que TCDD tem uma ampla ação, principalmente após o tratamento pré-pubertal com maior dose. As classes de genes mais afetadas foram proto-oncogenes, genes supressores de tumor e genes relacionados com o metabolismo de lipídeos. A via de sinalização mais atingida foi a via de sinalização do receptor de aril-hidrocarbono (AhR). Também se observou alterações na expressão de genes participantes da via de metabolização do estradiol, aumentando a produção de metabólitos prejudiciais ao DNA. CONCLUSÕES: O tratamento com TCDD resultou em mudanças na proliferação celular e na expressão gênica da glândula mamária das ratas. As mudanças gênicas observadas indicam que a célula mamária é submetida a estímulos genotóxicos ao mesmo tempo em que genes de reparo de DNA e supressores do crescimento tumoral ficam ativados no intuito de manter a estabilidade genômica.PURPOSE: This work studied the modifications in cell proliferation and gene expression in the rat mammary gland of animals 21, 35, 50 and 100 days old that were exposed to 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) during pregnancy (prenatal treatment) or during lactation (prepubertal treatment). METHODS: For the prenatal treatment, pregnant Sprague-Dawley rats received on the 15th day post-conception, single dose of 3.0µg TCDD/kg through gavage. For the prepubertal treatment, lactate dams received on the 14th and 17th days post-delivery either 6.67ng or 20.0ng TCDD/g. Control group received equivalent volume of sesame oil. When the female offspring reached 21, 35, 50 and 100 days of age, they were sacrificed and their mammary gland extracted for cell proliferation and gene expression analyses. To calculate the cell proliferation index, ten rats per group received an intraperitoneal injection of 200 mg/kg of 5-Bromo-2'- deoxyuridine (BrdU) and through immunohystochemistry the cells in proliferation were identified in each mammary gland structure. Other ten rats per group had the RNA extracted from the mammary gland and used for gene expression analysis through microarrays. To determine the differentially expressed genes empirical Bayes moderated one sample t-test was performed. Differentially expressed genes (p<0.01) were categorized accordingly with biological function and canonical pathways. In addition, important genes were validated through real time RT-PCR. RESULTS: The prepubertal treatment modified the cell proliferation of 35, 50 and 100 days-old rat mammary gland, mainly in the terminal end buds (TEBs). The gene expression analysis showed that the maximum number of differentially expressed genes was reached in 100 days-old rats that received TCDD during pregnancy. The prepubertal treatment induced more changes with higher dose of TCDD. Cyp1b1 was the gene the most up-regulated genes at different ages. The categorization of the dysregulated genes according with their biological function showed that TCDD has a wide action, especially after the prepubertal treatment with high dose. The groups of genes more affected by TCDD were the proto-oncogenes, tumor suppressor genes and genes related to the metabolism of lipids. The most affected canonical pathway was the aryl hydrocarbon receptor signaling pathway. In addition, genes related to estradiol metabolism were modulated increasing the production of metabolites that damage the DNA. CONCLUSIONS: The TCDD treatment induced changes in the cell proliferation and gene expression of the rat mammary gland. The genomic changes observed indicate that the mammary cell is submitted to genotoxic stimuli and DNA repair genes as tumor suppressor genes are activated to keep the genomic stability

The Genomic Signature of Breast Cancer Prevention

The breast of parous postmenopausal women exhibits a specific signature that has been induced by a full term pregnancy. This signature is centered in chromatin remodeling and the epigenetic changes induced by methylation of specific genes which are important regulatory pathways induced by pregnancy. Through the analysis of the genes found to be differentially methylated between women of varying parity, multiple positions at which beta-catenin production and use is inhibited were recognized. The biological importance of the pathways identified in this specific population cannot be sufficiently emphasized because they could represent a safeguard mechanism mediating the protection of the breast conferred by full term pregnancy

In utero exposure to butyl benzyl phthalate induces modifications in the morphology and the gene expression profile of the mammary gland : An experimental study in rats

Background: Environmental estrogens are exogenous estrogen-mimicking compounds that can interfere with endogenous endocrine systems. Several of these endocrine disruptors have been shown to alter normal development and influence tumorigenesis in experimental models. N-butyl benzyl phthalate (BBP), a widely used plasticizer, is a well-known endocrine disruptor. The aim of this study was to elucidate the effect of prenatal exposure to BBP on the morphology, proliferative index, and genomic signature of the rat mammary gland at different ages. Methods. In utero exposure was performed by gavage of pregnant Sprague Dawley CD rats with 120mg or 500mg BBP/kg/day from day 10 post-conception to delivery. Female litters were euthanized at 21, 35, 50 and 100 days. The morphology and proliferative index of the mammary gland were studied from whole mount preparations and BrdU incorporation, respectively. Gene expression profile was assessed by microarrays. Several genes found differentially expressed and related to different functional categories were further validated by real time RT-PCR. Results: Prenatal exposure of BBP induced delayed vaginal opening and changes in the post-natal mammary gland long after the end of the treatment, mainly by 35 days of age. Exposure to the high dose resulted in modifications in architecture and proliferative index of the mammary gland, mostly affecting the undifferentiated terminal end buds. Moreover, the expression profiles of this gland in the exposed rats were modified in a dose-dependent fashion. Analysis of functional categories showed that modified genes were related to immune function, cell signaling, proliferation and differentiation, or metabolism. Conclusions: Our data suggest that in utero exposure to BBP induced a delayed pubertal onset and modified morphology of the mammary gland. These alterations were accompanied by modifications in gene expression previously associated with an increased susceptibility to carcinogenesis

Prognostic value of P53 codon 72 polymorphism in invasive cervical cancer in Brazil

Objective. the prognostic value of p53 codon72 polymorphism was analyzed in Brazilian women with cervical cancer. Methods. the present study consists of 148 women diagnosed and treated for invasive cervical carcinoma (FIGO stages Ib-IIIb) between 1992 and 2002, Demonstration of p53 polymorphism was performed in DNA extracted from paraffin-embedded sections using the polymerase chain reaction (PCR).Results. Among the 148 women, arg/arg was found in 99 (67%) and, arg/pro in 49 (33%). the overall survival (OS) curves (univariate) were different between arg/arg and arg/pro patients (P = 0.01). There was slightly increased risk of death for arg/arg patients (crude HR 2.2 CI 95% 1.2-4.0), which was not confounded by FIGO stages (adjusted FIR 2.4 CI 95% 1.3-4.3). for disease-free survival (DFS), two situations were considered: (1) 124 women who received any treatment, and (2) 118 who received FIGO-recommended treatment. in the first group, 59% of arg/arg patients presented recurrence as compared to 32% in the arg/pro group (P = 0.02), whereas in the second group, 61% of the arg/arg and 34% arg/pro showed recurrence (P = 0.04). the risk of recurrence adjusted by FIGO stage for the 124 patients was 2.4 (CI 95% 1.0-3.7) and for the 118 it was 1.9 (CI 95% 1.0-3.4). These adjusted models showed no confounding and no interaction.Conclusions. Despite the prognostic significance of p53 polymorphism in univariate survival analysis, there was no or only marginal evidence on the independent prognostic value of p53arg/arg in multivariate analysis. the more ominous prognosis of the homozygous (arg/ arg) patients was explained by the primary treatment, independent on the FIGO stage. (C) 2004 Elsevier Inc. All rights reserved.Matern Hosp Leonor Mendes Barros, Hlth State Dept, BR-03015000 São Paulo, BrazilUniversidade Federal de São Paulo, Lab Mol Gynecol, BR-03015000 São Paulo, BrazilState Univ Campinas, Sch Med Sci, Campinas, BrazilUniv São Paulo, Med Sch Ribeirao Preto, Dept Social Med, São Paulo, BrazilIst Super Sanita, Epidemiol & Biostat Lab, Unit Cytopathol, I-00161 Rome, ItalyUniversidade Federal de São Paulo, Lab Mol Gynecol, BR-03015000 São Paulo, BrazilWeb of Scienc