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1.
J Immunother Cancer ; 12(4)2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38604812

RESUMEN

BACKGROUND: Ovarian cancer (OC) is the leading cause of death from gynecologic malignancies in the Western world. Contributing factors include a high frequency of late-stage diagnosis, the development of chemoresistance, and the evasion of host immune responses. Currently, debulking surgery and platinum-based chemotherapy are the treatment cornerstones, although recurrence is common. As the clinical efficacy of immune checkpoint blockade is low, new immunotherapeutic strategies are needed. Chimeric antigen receptor (CAR) T cell therapy empowers patients' own T cells to fight and eradicate cancer, and has been tested against various targets in OC. A promising candidate is the MUC16 ectodomain. This ectodomain remains on the cell surface after cleavage of cancer antigen 125 (CA125), the domain distal from the membrane, which is currently used as a serum biomarker for OC. CA125 itself has not been tested as a possible CAR target. In this study, we examined the suitability of the CA125 as a target for CAR T cell therapy. METHODS: We tested a series of antibodies raised against the CA125 extracellular repeat domain of MUC16 and adapted them to the CAR format. Comparisons between these candidates, and against an existing CAR targeting the MUC16 ectodomain, identified K101 as having high potency and specificity. The K101CAR was subjected to further biochemical and functional tests, including examination of the effect of soluble CA125 on its activity. Finally, we used cell lines and advanced orthotopic patient-derived xenograft (PDX) models to validate, in vivo, the efficiency of our K101CAR construct. RESULTS: We observed a high efficacy of K101CAR T cells against cell lines and patient-derived tumors, in vitro and in vivo. We also demonstrated that K101CAR functionality was not impaired by the soluble antigen. Finally, in direct comparisons, K101CAR, which targets the CA125 extracellular repeat domains, was shown to have similar efficacy to the previously validated 4H11CAR, which targets the MUC16 ectodomain. CONCLUSIONS: Our in vitro and in vivo results, including PDX studies, demonstrate that the CA125 domain of MUC16 represents an excellent target for treating MUC16-positive malignancies.


Asunto(s)
Antígeno Ca-125 , Proteínas de la Membrana , Femenino , Humanos , Antígeno Ca-125/metabolismo , Neoplasias Ováricas/tratamiento farmacológico
2.
Sci Rep ; 12(1): 15224, 2022 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-36076004

RESUMEN

Studies show that regularly consuming whole grains reduce the risk of obesity and a wide range of chronic diseases. Despite this, studies reveal that students are consuming fewer whole grains. In the present study, we aimed to investigate the barriers to the consumption of whole grains among Iranian students. This cross-sectional study examined students at Fasa, Iran in 2020-2021. The online questionnaires were completed by students after receiving informed consent. Statistical analysis was performed using SPSS 26 and Chi-square, t-test, and logistic regression (P > 0.05). The current study involved 1890 students (1287 (68.1%) girls and 603 (31.9%) boys). Despite the preference for white flour bread among 53.8% of all students, 77.4% ate other whole-grain products, and 75.2% consumed all products at least once a week. Additionally, barriers such as access issues (70.5%), family supply issues (91.8%), lack appeal (72.8%), non-consumption by classmates (96.2%), and high prices in recent years (43.9%) were identified as obstacles to whole grain consumption. Furthermore, white bread eating students had significantly lower appetite levels and tended to eat fast food more often than those who ate whole grains (P < 0.05). We found that slightly more than half of the participants preferred to eat bread prepared with refined flour. Several other factors, including lack of access, lack of attractiveness, product price, parents not purchasing whole-grain products, students not paying attention to nutrition labels, peers' effect, and eating with friends instead of family, also contribute to students avoiding whole-grain products.


Asunto(s)
Pan , Granos Enteros , Estudios Transversales , Grano Comestible , Femenino , Humanos , Irán , Masculino , Estudiantes
3.
J Educ Health Promot ; 10: 369, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34912905

RESUMEN

BACKGROUND: Human brucellosis can be a source of problems that affect public health, social, and economic well-being of the world's population. This study was conducted with the aim of determining the effect of Educational Intervention (EI) based on Health Belief Model (HBM) on preventive behaviors against brucellosis in Health Volunteers (HVs) in Rafsanjan. MATERIALS AND METHODS: Randomly, 104 HVs, in the intervention and control group, participated in a quasi-randomized, controlled experimental study. Variables were evaluated before and 1 month after intervention. In the intervention group, the educational program was conducted with lecture, group discussion, showing movies and related photos, booklets, and pamphlets. The program included five 45-min sessions that developed regarding the beliefs and constructs of HBM about brucellosis and its prevention methods. Data regarding HBM constructs and preventive behavior were collected using the questionnaire with 100 items by the self-report method. Finally, the data were entered into the SPSS software version 16.0, and statistical tests such as Chi-square, independent and paired t-test, Mann-Whitney, and Wilcoxon test were used for the data analysis at the significant level of 0.05. RESULTS: Prior to the intervention, the mean score of the HBM constructs and preventive behaviors between the two groups did not differ significantly, but 1 month later, in the intervention group increased significantly compared to the control group (P < 0.05). CONCLUSION: We recommend to health authorities and health-care providers to use HBM in EIs to create susceptibility, increase perceived severity and benefits, promote self-efficacy, uses cue to action, as well as reduce behavioral barriers, and ultimately adopt health-promoting behaviors.

4.
J Pers Med ; 11(5)2021 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-33922147

RESUMEN

Guidelines for genetic testing have been established for multiple tumor types, frequently indicating the most confident molecularly targeted treatment options. However, considering the often-complex presentation of individual cancer patients, in addition to the combinatorial complexity and inherent uncertainties of molecular findings, deriving optimal treatment strategies frequently becomes very challenging. Here, we report a comprehensive analysis of a 68-year-old male with metastatic prostate cancer, encompassing pathology and MRI findings, transcriptomic results, and key genomics findings from whole-exome sequencing, both somatic aberrations and germline variants. We identify multiple somatic aberrations that are known to be enriched in prostate cancer, including a deletion of PTEN and a fusion transcript involving BRCA2. The gene expression patterns in the tumor biopsy were also strikingly similar to prostate tumor samples from TCGA. Furthermore, we detected multiple lines of evidence for homologous recombination repair deficiency (HRD), including a dominant contribution by mutational signature SBS3, which is specifically attributed to HRD. On the basis of the genomic and transcriptomic findings, and in light of the clinical case presentation, we discussed the personalized treatment options that exist for this patient and the various challenges that one faces in the process of translating high-throughput sequencing data towards treatment regimens.

5.
JCI Insight ; 5(12)2020 06 18.
Artículo en Inglés | MEDLINE | ID: mdl-32365348

RESUMEN

Imprinted genes are highly expressed in the hypothalamus; however, whether specific imprinted genes affect hypothalamic neuromodulators and their functions is unknown. It has been suggested that Prader-Willi syndrome (PWS), a neurodevelopmental disorder caused by lack of paternal expression at chromosome 15q11-q13, is characterized by hypothalamic insufficiency. Here, we investigate the role of the paternally expressed Snord116 gene within the context of sleep and metabolic abnormalities of PWS, and we report a significant role of this imprinted gene in the function and organization of the 2 main neuromodulatory systems of the lateral hypothalamus (LH) - namely, the orexin (OX) and melanin concentrating hormone (MCH) - systems. We observed that the dynamics between neuronal discharge in the LH and the sleep-wake states of mice with paternal deletion of Snord116 (PWScrm+/p-) are compromised. This abnormal state-dependent neuronal activity is paralleled by a significant reduction in OX neurons in the LH of mutant mice. Therefore, we propose that an imbalance between OX- and MCH-expressing neurons in the LH of mutant mice reflects a series of deficits manifested in the PWS, such as dysregulation of rapid eye movement (REM) sleep, food intake, and temperature control.


Asunto(s)
Conducta Animal/fisiología , Área Hipotalámica Lateral/metabolismo , Hipotálamo/metabolismo , Orexinas/metabolismo , ARN Nucleolar Pequeño/genética , Sueño/fisiología , Animales , Modelos Animales de Enfermedad , Conducta Alimentaria , Área Hipotalámica Lateral/fisiopatología , Hormonas Hipotalámicas/metabolismo , Melaninas/metabolismo , Ratones , Neuronas/metabolismo , Hormonas Hipofisarias/metabolismo , Síndrome de Prader-Willi/metabolismo , Síndrome de Prader-Willi/fisiopatología
6.
BMC Cancer ; 18(1): 80, 2018 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-29338700

RESUMEN

After publication of the original article [1] the authors found that the article contained an incorrect version of Fig. 4. This does not affect the results and conclusions of the article.

7.
J Clin Diagn Res ; 11(2): ZC13-ZC16, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28384972

RESUMEN

INTRODUCTION: Cone Beam Computed Tomography (CBCT) has gained a broad acceptance in dentomaxillofacial imaging. Computed Tomography (CT) is another imaging modality for diagnosis and preoperative assessments of the head and neck region. AIM: Considering the increased radiation exposure and high cost of CT, this study sought to subjectively assess the image quality of CBCT and Multi Slice CT (MSCT). MATERIALS AND METHODS: A dry human mandible was scanned by five CBCT systems (New Tom 3G, Scanora, CRANEX 3D, Promax and Galileos) and one MSCT system. Three independent oral and maxillofacial radiologists reviewed the CBCT and MSCT scans for the quality of 10 landmarks namely mental foramen, trabecular bone, Periodontal Ligament (PDL), dentin, incisive canal, mandibular canal, dental pulp, enamel, lamina dura and cortical bone using a five-point scale. RESULTS: Significant differences were found between MSCT and CBCT and among the five CBCT systems (p<0.05) in visualization of different anatomical structures. A fine structure such as the incisive canal was significantly less visible and more variable among the systems in comparison with other anatomical landmarks such as the mental foramen, mandibular canal, cortical bone, dental pulp, enamel and dentin (p<0.05). The Cranex 3D and Promax systems were superior to MSCT and all other CBCT systems in visualizing anatomical structures. CONCLUSION: The CBCT image quality was superior to that of MSCT even though some variability existed among different CBCT systems in visualizing fine structures. Considering the low radiation dose and high resolution, CBCT may be beneficial for dentomaxillofacial imaging.

8.
J Hepatol ; 66(1): 116-122, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27647428

RESUMEN

BACKGROUND & AIMS: Recruitment of gut-derived memory T-cells to the liver is believed to drive hepatic inflammation in primary sclerosing cholangitis (PSC). However, whether gut-infiltrating and liver-infiltrating T-cells share T cell receptors (TCRs) and antigenic specificities is unknown. We used paired gut and liver samples from PSC patients with concurrent inflammatory bowel disease (PSC-IBD), and normal tissue samples from colon cancer controls, to assess potential T cell clonotype overlap between the two compartments. METHODS: High-throughput sequencing of TCRß repertoires was applied on matched colon, liver and blood samples from patients with PSC-IBD (n=10), and on paired tumor-adjacent normal gut and liver tissue samples from colon cancer patients (n=10). RESULTS: An average of 9.7% (range: 4.7-19.9%) memory T cell clonotypes overlapped in paired PSC-IBD affected gut and liver samples, after excluding clonotypes present at similar frequencies in blood. Shared clonotypes constituted on average 16.0% (range: 8.7-32.6%) and 15.0% (range: 5.9-26.3%) of the liver and gut memory T-cells, respectively. A significantly higher overlap was observed between paired PSC-IBD affected samples (8.7%, p=0.0007) compared to paired normal gut and liver samples (3.6%), after downsampling to equal number of reads. CONCLUSION: Memory T-cells of common clonal origin were detected in paired gut and liver samples of patients with PSC-IBD. Our data indicate that this is related to PSC-IBD pathogenesis, suggesting that memory T-cells driven by shared antigens are present in the gut and liver of PSC-IBD patients. Our findings support efforts to therapeutically target memory T cell recruitment in PSC-IBD. LAY SUMMARY: Primary sclerosing cholangitis (PSC) is a devastating liver disease strongly associated with inflammatory bowel disease (IBD). The cause of PSC is unknown, but it has been suggested that the immune reactions in the gut and the liver are connected. Our data demonstrate for the first time that a proportion of the T-cells in the gut and the liver react to similar triggers, and that this proportion is particularly high in patients with PSC and IBD.


Asunto(s)
Colangitis Esclerosante , Colon , Neoplasias del Colon , Enfermedades Inflamatorias del Intestino , Hígado , Colangitis Esclerosante/inmunología , Colangitis Esclerosante/patología , Colon/inmunología , Colon/patología , Neoplasias del Colon/inmunología , Neoplasias del Colon/patología , Femenino , Humanos , Inmunidad Celular/inmunología , Enfermedades Inflamatorias del Intestino/inmunología , Enfermedades Inflamatorias del Intestino/patología , Hígado/inmunología , Hígado/patología , Masculino , Persona de Mediana Edad , Estadística como Asunto , Linfocitos T/inmunología , Linfocitos T/patología
9.
BMC Cancer ; 16(1): 913, 2016 11 22.
Artículo en Inglés | MEDLINE | ID: mdl-27876019

RESUMEN

BACKGROUND: Detection and localization of genomic alterations and breakpoints are crucial in cancer research. The purpose of this study was to investigate, in a methodological and biological perspective, different female, hormone-dependent cancers to identify common and diverse DNA aberrations, genes, and pathways. METHODS: In this work, we analyzed tissue samples from patients with breast (n = 112), ovarian (n = 74), endometrial (n = 84), or cervical (n = 76) cancer. To identify genomic aberrations, the Circular Binary Segmentation (CBS) and Piecewise Constant Fitting (PCF) algorithms were used and segmentation thresholds optimized. The Genomic Identification of Significant Targets in Cancer (GISTIC) algorithm was applied to the segmented data to identify significantly altered regions and the associated genes were analyzed by Ingenuity Pathway Analysis (IPA) to detect over-represented pathways and functions within the identified gene sets. RESULTS AND DISCUSSION: Analyses of high-resolution copy number alterations in four different female cancer types are presented. For appropriately adjusted segmentation parameters the two segmentation algorithms CBS and PCF performed similarly. We identified one region at 8q24.3 with focal aberrations that was altered at significant frequency across all four cancer types. Considering both, broad regions and focal peaks, three additional regions with gains at significant frequency were revealed at 1p21.1, 8p22, and 13q21.33, respectively. Several of these events involve known cancer-related genes, like PPP2R2A, PSCA, PTP4A3, and PTK2. In the female reproductive system (ovarian, endometrial, and cervix [OEC]), we discovered three common events: copy number gains at 5p15.33 and 15q11.2, further a copy number loss at 8p21.2. Interestingly, as many as 75% of the aberrations (75% amplifications and 86% deletions) identified by GISTIC were specific for just one cancer type and represented distinct molecular pathways. CONCLUSIONS: Our results disclose that some prominent copy number changes are shared in the four examined female, hormone-dependent cancer whereas others are definitive to specific cancer types.


Asunto(s)
Variaciones en el Número de Copia de ADN , Estudios de Asociación Genética , Neoplasias/diagnóstico , Neoplasias/genética , Neoplasias de la Mama/genética , Análisis por Conglomerados , Bases de Datos Genéticas , Neoplasias Endometriales/genética , Femenino , Amplificación de Genes , Eliminación de Gen , Perfilación de la Expresión Génica , Predisposición Genética a la Enfermedad , Genómica/métodos , Humanos , Neoplasias Ováricas/genética , Factores Sexuales , Neoplasias del Cuello Uterino/genética
10.
Am J Gastroenterol ; 111(10): 1467-1475, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27527747

RESUMEN

OBJECTIVES: The objective of this study was to study the prevalence of gastrointestinal (GI) symptoms and histopathology in patients with common variable immunodeficiency (CVID) as well as linking the findings to GI infections and markers of systemic immune activation. METHODS: In this cross-sectional study, we addressed GI symptoms in 103 patients and GI histopathological findings in 53 patients who underwent upper and lower endoscopic examination. The most frequent histopathological findings were linked to GI symptoms, B-cell phenotype, and markers of systemic immune activation (soluble (s)CD14, sCD25, and sCD163). Microarray analysis compared "celiac-like disease" in CVID to celiac disease. Screening for selected bacterial and viral infections in fecal samples and gut mucosal biopsies was performed. RESULTS: The main findings of this study were as follows: most common GI symptoms were bloating (34%), pain (30%), and diarrhea (26%). The most frequent histopathological findings were increased intraepithelial lymphocytes in the descending part of the duodenum, i.e., "celiac-like disease" (46% of patients), decreased numbers of plasma cells in GI tract mucosa (62%), and lymphoid hyperplasia (38%), none of which were associated with GI symptoms. Reduced plasma cells in GI mucosa were associated with B-cell phenotypic characteristics of CVID, and increased serum levels of sCD14 (P=0.025), sCD25 (P=0.01), and sCD163 (P=0.04). Microarray analyses distinguished between CVID patients with "celiac-like disease" and celiac disease. Positive tests for bacterial and viral infections were scarce both in fecal samples and gut mucosal biopsies, including PCR test for norovirus in biopsy specimens (0 positive tests). CONCLUSIONS: In conclusion, GI pathology is common in CVID, but does not necessarily cause symptoms. However, reduced plasma cells in GI mucosa were linked to systemic immune activation, "celiac-like disease" in CVID and true celiac disease appear to be different disease entities, as assessed by gene expression, and infections (including norovirus) are rarely a cause of the CVID enteropathy.


Asunto(s)
Inmunodeficiencia Variable Común/epidemiología , Enfermedades Gastrointestinales/epidemiología , Dolor Abdominal/epidemiología , Dolor Abdominal/inmunología , Dolor Abdominal/patología , Adulto , Anciano , Anciano de 80 o más Años , Linfocitos B/inmunología , Enfermedad Celíaca/epidemiología , Enfermedad Celíaca/genética , Enfermedad Celíaca/inmunología , Enfermedad Celíaca/patología , Colonoscopía , Inmunodeficiencia Variable Común/inmunología , Estreñimiento/epidemiología , Estreñimiento/inmunología , Estreñimiento/patología , Estudios Transversales , Diarrea/epidemiología , Diarrea/inmunología , Diarrea/patología , Duodeno/patología , Endoscopía del Sistema Digestivo , Mucosa Esofágica/patología , Femenino , Mucosa Gástrica/patología , Enfermedades Gastrointestinales/genética , Enfermedades Gastrointestinales/inmunología , Enfermedades Gastrointestinales/patología , Tracto Gastrointestinal/patología , Humanos , Mucosa Intestinal/patología , Linfocitos/patología , Masculino , Persona de Mediana Edad , Células Plasmáticas/patología , Prevalencia , Transcriptoma , Adulto Joven
11.
Hepatology ; 63(5): 1608-19, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26257205

RESUMEN

UNLABELLED: Hepatic T-cell infiltrates and a strong genetic human leukocyte antigen association represent characteristic features of various immune-mediated liver diseases. Conceptually the presence of disease-associated antigens is predicted to be reflected in T-cell receptor (TCR) repertoires. Here, we aimed to determine if disease-associated TCRs could be identified in the nonviral chronic liver diseases primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC), and alcoholic liver disease (ALD). We performed high-throughput sequencing of the TCRß chain complementarity-determining region 3 of liver-infiltrating T cells from PSC (n = 20), PBC (n = 10), and ALD (n = 10) patients, alongside genomic human leukocyte antigen typing. The frequency of TCRß nucleotide sequences was significantly higher in PSC samples (2.53 ± 0.80, mean ± standard error of the mean) compared to PBC samples (1.13 ± 0.17, P < 0.0001) and ALD samples (0.62 ± 0.10, P < 0.0001). An average clonotype overlap of 0.85% was detected among PSC samples, significantly higher compared to the average overlap of 0.77% seen within the PBC (P = 0.024) and ALD groups (0.40%, P < 0.0001). From eight to 42 clonotypes were uniquely detected in each of the three disease groups (≥30% of the respective patient samples). Multiple, unique sequences using different variable family genes encoded the same amino acid clonotypes, providing additional support for antigen-driven selection. In PSC and PBC, disease-associated clonotypes were detected among patients with human leukocyte antigen susceptibility alleles. CONCLUSION: We demonstrate liver-infiltrating disease-associated clonotypes in all three diseases evaluated, and evidence for antigen-driven clonal expansions. Our findings indicate that differential TCR signatures, as determined by high-throughput sequencing, may represent an imprint of distinctive antigenic repertoires present in the different chronic liver diseases; this thereby opens up the prospect of studying disease-relevant T cells in order to better understand and treat liver disease.


Asunto(s)
Colangitis Esclerosante/inmunología , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Cirrosis Hepática Biliar/inmunología , Hepatopatías Alcohólicas/inmunología , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Adulto , Enfermedad Crónica , Femenino , Genes Codificadores de la Cadena beta de los Receptores de Linfocito T , Humanos , Masculino , Persona de Mediana Edad
12.
Breast Cancer Res ; 17: 44, 2015 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-25882602

RESUMEN

INTRODUCTION: Hypercoagulability in malignancy increases the risk of thrombosis, but is also involved in cancer progression. Experimental studies suggest that tissue factor (TF) and tissue factor pathway inhibitor (TFPI) are involved in cancer biology as a tumor- promoter and suppressor, respectively, but the clinical significance is less clear. Here, we aimed to investigate the clinical relevance of TF and TFPI genetic and phenotypic diversity in breast cancer. METHODS: The relationship between tumor messenger RNA (mRNA) expression and plasma levels of TF and TFPI (α and ß), tagging single nucleotide polymorphisms (tagSNPs) in F3 (TF) (n=6) and TFPI (n=18), and clinicopathological characteristics and molecular tumor subtypes were explored in 152 treatment naive breast cancer patients. The effect of tumor expressed TF and TFPIα and TFPIß on survival was investigated in a merged breast cancer dataset of 1881 patients. RESULTS: Progesterone receptor negative patients had higher mRNA expression of total TFPI (α+ß) (P=0.021) and TFPIß (P=0.014) in tumors. TF mRNA expression was decreased in grade 3 tumors (P=0.003). In plasma, total TFPI levels were decreased in patients with larger tumors (P=0.013). SNP haplotypes of TFPI, but not TF, were associated with specific clinicopathological characteristics like tumor size (odds ratio (OR) 3.14, P=0.004), triple negativity (OR 2.4, P=0.004), lymph node spread (OR 3.34, P=0.006), and basal-like (OR 2.3, P=0.011) and luminal B (OR 3.5, P=0.005) molecular tumor subtypes. Increased expression levels of TFPIα and TFPIß in breast tumors were associated with better outcome in all tumor subtypes combined (P=0.007 and P=0.005) and in multiple subgroups, including lymph node positive subjects (P=0.006 and P=0.034). CONCLUSIONS: This study indicates that genetic and phenotypic variation of both TFPIα and TFPIß, more than TF, are markers of cancer progression. Together with the previously demonstrated tumor suppressor effects of TFPI, the beneficial effect of tumor expressed TFPI on survival, renders TFPI as a potential anticancer agent, and the clinical significance of TFPI in cancer deserves further investigation.


Asunto(s)
Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Expresión Génica , Lipoproteínas/genética , Lipoproteínas/metabolismo , Polimorfismo de Nucleótido Simple , Adulto , Anciano , Alelos , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Femenino , Estudios de Asociación Genética , Genotipo , Haplotipos , Humanos , Lipoproteínas/sangre , Persona de Mediana Edad , Clasificación del Tumor , Metástasis de la Neoplasia , Estadificación de Neoplasias , Fenotipo , Pronóstico , ARN Mensajero/genética , Tromboplastina/genética , Tromboplastina/metabolismo , Carga Tumoral
13.
BMC Med Genomics ; 4: 85, 2011 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-22188678

RESUMEN

BACKGROUND: In a cancer cell the number of copies of a locus may vary due to amplification and deletion and these variations are denoted as copy number alterations (CNAs). We focus on the disparity of CNAs in tumour samples, which were compared to those in blood in order to identify the directional loss of heterozygosity. METHODS: We propose a numerical algorithm and apply it to data from the Illumina 109K-SNP array on 112 samples from breast cancer patients. B-allele frequency (BAF) and log R ratio (LRR) of Illumina were used to estimate Euclidian distances. For each locus, we compared genotypes in blood and tumour for subset of samples being heterozygous in blood. We identified loci showing preferential disparity from heterozygous toward either the A/B-allele homozygous (allelic disparity). The chi-squared and Cochran-Armitage trend tests were used to examine whether there is an association between high levels of disparity in single nucleotide polymorphisms (SNPs) and molecular, clinical and tumour-related parameters. To identify pathways and network functions over-represented within the resulting gene sets, we used Ingenuity Pathway Analysis (IPA). RESULTS: To identify loci with a high level of disparity, we selected SNPs 1) with a substantial degree of disparity and 2) with substantial frequency (at least 50% of the samples heterozygous for the respective locus). We report the overall difference in disparity in high-grade tumours compared to low-grade tumours (p-value < 0.001) and significant associations between disparity in multiple single loci and clinical parameters. The most significantly associated network functions within the genes represented in the loci of disparity were identified, including lipid metabolism, small-molecule biochemistry, and nervous system development and function. No evidence for over-representation of directional disparity in a list of stem cell genes was obtained, however genes appeared to be more often altered by deletion than by amplification. CONCLUSIONS: Our data suggest that directional loss and amplification exist in breast cancer. These are highly associated with grade, which may indicate that they are enforced with increasing number of cell divisions. Whether there is selective pressure for some loci to be preferentially amplified or deleted remains to be confirmed.


Asunto(s)
Alelos , Neoplasias de la Mama/genética , Algoritmos , Neoplasias de la Mama/sangre , Neoplasias de la Mama/patología , Aberraciones Cromosómicas , Biología Computacional , Variaciones en el Número de Copia de ADN/genética , Amplificación de Genes/genética , Humanos , Pérdida de Heterocigocidad/genética , Clasificación del Tumor , Células Madre Neoplásicas/metabolismo , Polimorfismo de Nucleótido Simple/genética , Eliminación de Secuencia/genética
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