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1.
BMC Cancer ; 14: 830, 2014 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-25403427

RESUMEN

BACKGROUND: BRCA1 promoter methylation has been detected in DNA from peripheral blood cells of both breast cancer patients and cancer-free females. However, the pathological significance of this epigenetic change in white blood cells (WBC) remains an open question. In this study, we hypothesized that if constitutional BRCA1 methylation reflects an elevated risk for developing breast cancer (BC), WBC that harbor methylated BRCA1 in both cancer-free females and BC patients should exhibit similar molecular changes. METHODS: BRCA1 promoter methylation was examined by methylation-specific PCR in WBC from 155 breast cancer patients and 143 cancer-free females. The Human Breast Cancer EpiTect Methyl II Signature PCR Array and The Human Breast Cancer RT2 Profiler™ PCR Array were used to study the methylation status and the expression profile of several breast cancer-related genes, respectively. In addition, we used label-free MS-based technique to study protein expression in plasma. RESULTS: We have shown that 14.2% of BC patients and 9.1% of cancer-free females (carriers) harbored methylated BRCA1 promoter in their WBC. Interestingly, 66.7% of patients harbored methylated BRCA1 promoter in both WBC and tumors. Importantly, we have shown the presence of epigenetic changes in 9 other BC-related genes in WBC of both patients and carriers. Additionally, BRCA1 and 15 other important cancer -related genes were found to be differentially expressed in WBC from patients and carriers as compared to controls. Furthermore, we have shown that the carriers exhibited a unique plasma protein pattern different from those of BC patients and controls, with 10 proteins similarly differentially expressed in patients and carriers as compared to controls. CONCLUSIONS: The present results suggest the presence of a strong link between aberrant methylation of the BRCA1 promoter in WBC and breast cancer -related molecular changes, which indicate the potential predisposition of the carriers for developing breast cancer. This informs the potential use of the aberrant methylation of BRCA1 promoter in WBC as a powerful non-invasive molecular marker for detecting predisposed individuals at a very early age.


Asunto(s)
Proteína BRCA1/genética , Metilación de ADN , Leucocitos/metabolismo , Regiones Promotoras Genéticas , Transcriptoma , Adolescente , Adulto , Anciano , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Análisis por Conglomerados , Epigénesis Genética , Femenino , Perfilación de la Expresión Génica , Heterocigoto , Humanos , Glándulas Mamarias Humanas/metabolismo , Persona de Mediana Edad , Clasificación del Tumor , Adulto Joven
2.
Saudi Med J ; 29(4): 507-13, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18382789

RESUMEN

OBJECTIVE: To generate consensus gene expression profiles of invasive breast tumors from a small cohort of Saudi females, and to explore the possibility that they may be broadly conserved between Caucasian and Middle Eastern populations. METHODS: This study was performed at King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia, from January 2005 to January 2007. Gene expression profiles were generated from 38 invasive breast tumors, and 8 tumor adjacent tissues TATs using BD Atlas cDNA expression arrays containing 1176 genes. Results were confirmed by reverse transcriptase polymerase chain reaction, and analyzed by 2-dimensional unsupervised hierarchical clustering. RESULTS: The analysis identified 48 differentially expressed genes in tumors from which 25 are already reported by various western studies. Forty-three of these genes were also differentially expressed in TATs. The same data set has been able to distinguish between tumors and the TATs, interestingly by using only 4 of the differentially expressed genes. Moreover, we were able to group the patients according to prognosis to an extent by hierarchical clustering. CONCLUSION: Our results indicate that expression profiles between Saudi females with breast cancer and the Caucasian population are conserved to some extent, and can be used to classify patients according to prognostic groups. We also suggest 3 differentially-expressed genes IGHG3, CDK6, and RPS9 in tumors may have a novel role in breast cancer. In addition, the role of TATs is much more essential in breast cancer, and needs to be explored thoroughly.


Asunto(s)
Neoplasias de la Mama/genética , Perfilación de la Expresión Génica , Adulto , Femenino , Expresión Génica , Humanos , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Arabia Saudita
3.
Saudi Med J ; 27(4): 463-9, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16598321

RESUMEN

OBJECTIVE: The study was designed to examine whether the gene expression profiles of fibroblast cell lines, established from the tumor and the normal tissue from the same breast, exhibit any similarities with the profiles of the original tissues. METHODS: Fibroblast cell lines were established from invasive ductal carcinoma (IDC) and ductal carcinoma in situ (DCIS) of the breast and the adjacent normal tissues. Isolated total RNA from the cell lines and tissues were used to prepare labeled cDNA which was hybridized to Becton Dickinson Atlas microarrays for obtaining profiles of expressed genes. The profiles of tumors and cell lines were compared. This study was carried out at King Faisal specialist Hospital and Research Center, Riyadh, Kingdom of Saudi Arabia, during 2004 and 2005. RESULTS: Alterations of expression of most of the genes in the tissues were not detectable in the cell lines. The expression of a lower number of genes was altered in DCIS compared with that in IDC tumors. CONCLUSION: Although the fibroblasts discharge important functions, their gene expression profiles do not represent the breast tissue to the extent that any prognostic decisions could be made.


Asunto(s)
Neoplasias de la Mama/genética , Carcinoma Ductal de Mama/genética , Carcinoma Intraductal no Infiltrante/genética , Fibroblastos/fisiología , Adulto , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/patología , Carcinoma Intraductal no Infiltrante/patología , Estudios de Casos y Controles , Femenino , Perfilación de la Expresión Génica , Humanos , Persona de Mediana Edad , Análisis de Secuencia por Matrices de Oligonucleótidos
4.
Saudi Med J ; 24(11): 1199-204, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14647553

RESUMEN

OBJECTIVE: A number of techniques have been developed to perform gene expression profiling. We report preliminary results from our exploratory study, using sequential analysis of gene expression (SAGE) technique, to profile the undifferentiated and differentiated HL-60 cells in line with our interest to characterize the cancer phenotype. The aim of the study is to evaluate the technique and to understand the molecular bases of these 2 states of cells. METHODS: HL-60 cells were differentiated after treatment with dimethyl sulfoxide. Tag libraries were prepared from the messenger RNAs of the undifferentiated and differentiated cells according to the SAGE protocol. The search for genes corresponding to the tags was carried out using SAGE software. The tags and the genes from the 2 libraries were compared for their levels of expression. The study was carried out at the King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia during the year 2001. RESULTS: A comparison of tags from the 2 libraries revealed that 151 tags corresponding to 57 genes expressed differentially: 60 tags were elevated and 59 were repressed in the undifferentiated cells. Thirty-two tags were equally expressed in both types of cells. Of the corresponding genes, 25 were expressed at higher, 17 at lower, while 15 were expressed at comparable levels in both cell types. In the profile of undifferentiated cells, the genes involved in mitochondrial function and protein synthesis were prominent, while in the differentiated cells, the genes coding for proteins associated with cell membranes, signal transduction and for cell specific functions were prominent. The genes, expressed equally in both the cell types, were concerned with the maintenance of the living state. CONCLUSION: Sequential analysis of gene expression is a useful technique for gene expression profiling. As previously indicated by others, a dedicated team can generate useful data within reasonable time limits.


Asunto(s)
Perfilación de la Expresión Génica/métodos , Células HL-60 , Diferenciación Celular , Estudios de Evaluación como Asunto , Etiquetas de Secuencia Expresada , Regulación Neoplásica de la Expresión Génica , Biblioteca de Genes , Humanos , Arabia Saudita , Factores de Tiempo
5.
PLoS One ; 8(5): e63204, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23704896

RESUMEN

Breast cancer in young women is more aggressive with a poorer prognosis and overall survival compared to older women diagnosed with the disease. Despite recent research, the underlying biology and molecular alterations that drive the aggressive nature of breast tumors associated with breast cancer in young women have yet to be elucidated. In this study, we performed transcriptomic profile and network analyses of breast tumors arising in Middle Eastern women to identify age-specific gene signatures. Moreover, we studied molecular alterations associated with cancer progression in young women using cross-species comparative genomics approach coupled with copy number alterations (CNA) associated with breast cancers from independent studies. We identified 63 genes specific to tumors in young women that showed alterations distinct from two age cohorts of older women. The network analyses revealed potential critical regulatory roles for Myc, PI3K/Akt, NF-κB, and IL-1 in disease characteristics of breast tumors arising in young women. Cross-species comparative genomics analysis of progression from pre-invasive ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC) revealed 16 genes with concomitant genomic alterations, CCNB2, UBE2C, TOP2A, CEP55, TPX2, BIRC5, KIAA0101, SHCBP1, UBE2T, PTTG1, NUSAP1, DEPDC1, HELLS, CCNB1, KIF4A, and RRM2, that may be involved in tumorigenesis and in the processes of invasion and progression of disease. Array findings were validated using qRT-PCR, immunohistochemistry, and extensive in silico analyses of independently performed microarray datasets. To our knowledge, this study provides the first comprehensive genomic analysis of breast cancer in Middle Eastern women in age-specific cohorts and potential markers for cancer progression in young women. Our data demonstrate that cancer appearing in young women contain distinct biological characteristics and deregulated signaling pathways. Moreover, our integrative genomic and cross-species analysis may provide robust biomarkers for the detection of disease progression in young women, and lead to more effective treatment strategies.


Asunto(s)
Envejecimiento/genética , Biomarcadores de Tumor/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Progresión de la Enfermedad , Transcriptoma , Adulto , Envejecimiento/patología , Animales , Biomarcadores de Tumor/metabolismo , Carcinogénesis/genética , Carcinogénesis/patología , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/patología , Carcinoma Intraductal no Infiltrante/genética , Carcinoma Intraductal no Infiltrante/patología , Estudios de Cohortes , Biología Computacional , Femenino , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes/genética , Genes Relacionados con las Neoplasias/genética , Genoma Humano/genética , Humanos , Inmunohistoquímica , Ratones , Persona de Mediana Edad , Análisis de Secuencia por Matrices de Oligonucleótidos , Reproducibilidad de los Resultados , Especificidad de la Especie , Adulto Joven
6.
Int J Cancer ; 121(4): 751-8, 2007 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-17415709

RESUMEN

B7-H1, a co-inhibitory molecule, plays a role in immune escape of tumors. We have shown previously the expression of this molecule in breast cancer patients and demonstrated its association with high histological grade, progesterone and estrogen receptor negative status, all of which are known to have direct impact on cell proliferation. In the present work, we investigated the effect of proliferation, as measured by Ki-67 and mitotic count, on the induction of B7-H1. We used H&E stained sections to score for mitotic count in 69 breast cancer patients. Immunohistochemistry was used to investigate B7-H1 and Ki-67 expression. The relationship between B7-H1 induction and cell proliferation was further investigated in primary cultured cells. B7-H1 expression was recorded in patients with a high mitotic index (p = 0.007). There was a high significant correlation between B7-H1 expression and the presence of the proliferative marker Ki-67 (p < 0.001) indicating the association of proliferation with B7-H1 induction. Furthermore, B7-H1 was gradually induced in proliferating cells of 8/8 primary cell lines as measured by Ki-67 expression. Finally, B7-H1 was downregulated in quiescent cells and upregulated in cells stimulated with a mitogen confirming the association of proliferation with the induction of B7-H1. We have shown for the first time a direct association between proliferation and the expression of B7-H1 in breast cancer patients. The relationship between B7-H1 induction and cell proliferation was also thoroughly investigated in vitro, in which a strong link between B7-H1 expression and the presence of the proliferative Ki-67 marker was clearly demonstrated.


Asunto(s)
Antígenos CD/metabolismo , Neoplasias de la Mama/metabolismo , Antígeno Ki-67/metabolismo , Adulto , Antígeno B7-H1 , Neoplasias de la Mama/patología , Ciclo Celular , Línea Celular Tumoral , Proliferación Celular , Femenino , Humanos , Inmunohistoquímica , Índice Mitótico , Neoplasias Hormono-Dependientes/metabolismo , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , Fase de Descanso del Ciclo Celular
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