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1.
Nature ; 548(7666): 239-243, 2017 08 10.
Article in English | MEDLINE | ID: mdl-28783725

ABSTRACT

The initiating oncogenic event in almost half of human lung adenocarcinomas is still unknown, a fact that complicates the development of selective targeted therapies. Yet these tumours harbour a number of alterations without obvious oncogenic function including BRAF-inactivating mutations. Inactivating BRAF mutants in lung predominate over the activating V600E mutant that is frequently observed in other tumour types. Here we demonstrate that the expression of an endogenous Braf(D631A) kinase-inactive isoform in mice (corresponding to the human BRAF(D594A) mutation) triggers lung adenocarcinoma in vivo, indicating that BRAF-inactivating mutations are initiating events in lung oncogenesis. Moreover, inactivating BRAF mutations have also been identified in a subset of KRAS-driven human lung tumours. Co-expression of Kras(G12V) and Braf(D631A) in mouse lung cells markedly enhances tumour initiation, a phenomenon mediated by Craf kinase activity, and effectively accelerates tumour progression when activated in advanced lung adenocarcinomas. We also report a key role for the wild-type Braf kinase in sustaining Kras(G12V)/Braf(D631A)-driven tumours. Ablation of the wild-type Braf allele prevents the development of lung adenocarcinoma by inducing a further increase in MAPK signalling that results in oncogenic toxicity; this effect can be abolished by pharmacological inhibition of Mek to restore tumour growth. However, the loss of wild-type Braf also induces transdifferentiation of club cells, which leads to the rapid development of lethal intrabronchiolar lesions. These observations indicate that the signal intensity of the MAPK pathway is a critical determinant not only in tumour development, but also in dictating the nature of the cancer-initiating cell and ultimately the resulting tumour phenotype.


Subject(s)
Adenocarcinoma/genetics , Loss of Function Mutation , Lung Neoplasms/genetics , Proto-Oncogene Proteins B-raf/genetics , Adenocarcinoma/pathology , Alleles , Animals , Carcinogenesis/genetics , Disease Progression , Female , Genes, Neurofibromatosis 1 , Humans , Lung Neoplasms/pathology , MAP Kinase Signaling System , Male , Mice , Mice, Inbred C57BL , Proto-Oncogene Proteins B-raf/metabolism , Proto-Oncogene Proteins p21(ras)/metabolism
2.
Nature ; 526(7574): 519-24, 2015 Oct 22.
Article in English | MEDLINE | ID: mdl-26200345

ABSTRACT

Chronic lymphocytic leukaemia (CLL) is a frequent disease in which the genetic alterations determining the clinicobiological behaviour are not fully understood. Here we describe a comprehensive evaluation of the genomic landscape of 452 CLL cases and 54 patients with monoclonal B-lymphocytosis, a precursor disorder. We extend the number of CLL driver alterations, including changes in ZNF292, ZMYM3, ARID1A and PTPN11. We also identify novel recurrent mutations in non-coding regions, including the 3' region of NOTCH1, which cause aberrant splicing events, increase NOTCH1 activity and result in a more aggressive disease. In addition, mutations in an enhancer located on chromosome 9p13 result in reduced expression of the B-cell-specific transcription factor PAX5. The accumulative number of driver alterations (0 to ≥4) discriminated between patients with differences in clinical behaviour. This study provides an integrated portrait of the CLL genomic landscape, identifies new recurrent driver mutations of the disease, and suggests clinical interventions that may improve the management of this neoplasia.


Subject(s)
Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Mutation/genetics , 3' Untranslated Regions/genetics , Alternative Splicing/genetics , B-Lymphocytes/metabolism , Carrier Proteins/genetics , Chromosomes, Human, Pair 9/genetics , DNA Mutational Analysis , DNA, Neoplasm/genetics , DNA-Binding Proteins , Enhancer Elements, Genetic/genetics , Genomics , Humans , Leukemia, Lymphocytic, Chronic, B-Cell/metabolism , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Nerve Tissue Proteins/genetics , Nuclear Proteins/genetics , PAX5 Transcription Factor/biosynthesis , PAX5 Transcription Factor/genetics , Protein Tyrosine Phosphatase, Non-Receptor Type 11/genetics , Receptor, Notch1/genetics , Receptor, Notch1/metabolism , Transcription Factors/genetics
3.
Gut ; 66(8): 1449-1462, 2017 08.
Article in English | MEDLINE | ID: mdl-27053631

ABSTRACT

OBJECTIVE: Colorectal cancer (CRC) is a major health concern. Vitamin D deficiency is associated with high CRC incidence and mortality, suggesting a protective effect of vitamin D against this disease. Given the strong influence of tumour stroma on cancer progression, we investigated the potential effects of the active vitamin D metabolite 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) on CRC stroma. DESIGN: Expression of vitamin D receptor (VDR) and two 1,25(OH)2D3 target genes was analysed in 658 patients with CRC with prolonged clinical follow-up. 1,25(OH)2D3 effects on primary cultures of patient-derived colon normal fibroblasts (NFs) and cancer-associated fibroblasts (CAFs) were studied using collagen gel contraction and migration assays and global gene expression analyses. Publicly available data sets (n=877) were used to correlate the 1,25(OH)2D3-associated gene signature in CAFs with CRC outcome. RESULTS: High VDR expression in tumour stromal fibroblasts was associated with better overall survival (OS) and progression-free survival in CRC, independently of its expression in carcinoma cells. 1,25(OH)2D3 inhibited the protumoural activation of NFs and CAFs and imposed in CAFs a 1,25(OH)2D3-associated gene signature that correlated with longer OS and disease-free survival in CRC. Furthermore, expression of two genes from the signature, CD82 and S100A4, correlated with stromal VDR expression and clinical outcome in our cohort of patients with CRC. CONCLUSIONS: 1,25(OH)2D3 has protective effects against CRC through the regulation of stromal fibroblasts. Accordingly, expression of VDR and 1,25(OH)2D3-associated gene signature in stromal fibroblasts predicts a favourable clinical outcome in CRC. Therefore, treatment of patients with CRC with VDR agonists could be explored even in the absence of VDR expression in carcinoma cells.


Subject(s)
Calcitriol/pharmacology , Cancer-Associated Fibroblasts/metabolism , Carcinoma/genetics , Carcinoma/metabolism , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Receptors, Calcitriol/metabolism , Vitamins/pharmacology , Carcinoma/chemistry , Cell Movement/drug effects , Cells, Cultured , Collagen/drug effects , Colorectal Neoplasms/chemistry , Disease-Free Survival , Gene Expression/drug effects , Humans , Kangai-1 Protein/genetics , Receptors, Calcitriol/analysis , S100 Calcium-Binding Protein A4/genetics , Survival Rate , Transcriptome
4.
Genome Res ; 24(2): 212-26, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24265505

ABSTRACT

Chronic lymphocytic leukemia (CLL) has heterogeneous clinical and biological behavior. Whole-genome and -exome sequencing has contributed to the characterization of the mutational spectrum of the disease, but the underlying transcriptional profile is still poorly understood. We have performed deep RNA sequencing in different subpopulations of normal B-lymphocytes and CLL cells from a cohort of 98 patients, and characterized the CLL transcriptional landscape with unprecedented resolution. We detected thousands of transcriptional elements differentially expressed between the CLL and normal B cells, including protein-coding genes, noncoding RNAs, and pseudogenes. Transposable elements are globally derepressed in CLL cells. In addition, two thousand genes-most of which are not differentially expressed-exhibit CLL-specific splicing patterns. Genes involved in metabolic pathways showed higher expression in CLL, while genes related to spliceosome, proteasome, and ribosome were among the most down-regulated in CLL. Clustering of the CLL samples according to RNA-seq derived gene expression levels unveiled two robust molecular subgroups, C1 and C2. C1/C2 subgroups and the mutational status of the immunoglobulin heavy variable (IGHV) region were the only independent variables in predicting time to treatment in a multivariate analysis with main clinico-biological features. This subdivision was validated in an independent cohort of patients monitored through DNA microarrays. Further analysis shows that B-cell receptor (BCR) activation in the microenvironment of the lymph node may be at the origin of the C1/C2 differences.


Subject(s)
B-Lymphocytes , Gene Expression Regulation, Neoplastic , High-Throughput Nucleotide Sequencing , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Aged , Base Sequence , Female , Gene Expression Profiling , Humans , Immunoglobulin Variable Region , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Male , Middle Aged , Mutation , Ribosomes/genetics , Spliceosomes/genetics
5.
Nature ; 475(7354): 101-5, 2011 Jun 05.
Article in English | MEDLINE | ID: mdl-21642962

ABSTRACT

Chronic lymphocytic leukaemia (CLL), the most frequent leukaemia in adults in Western countries, is a heterogeneous disease with variable clinical presentation and evolution. Two major molecular subtypes can be distinguished, characterized respectively by a high or low number of somatic hypermutations in the variable region of immunoglobulin genes. The molecular changes leading to the pathogenesis of the disease are still poorly understood. Here we performed whole-genome sequencing of four cases of CLL and identified 46 somatic mutations that potentially affect gene function. Further analysis of these mutations in 363 patients with CLL identified four genes that are recurrently mutated: notch 1 (NOTCH1), exportin 1 (XPO1), myeloid differentiation primary response gene 88 (MYD88) and kelch-like 6 (KLHL6). Mutations in MYD88 and KLHL6 are predominant in cases of CLL with mutated immunoglobulin genes, whereas NOTCH1 and XPO1 mutations are mainly detected in patients with unmutated immunoglobulins. The patterns of somatic mutation, supported by functional and clinical analyses, strongly indicate that the recurrent NOTCH1, MYD88 and XPO1 mutations are oncogenic changes that contribute to the clinical evolution of the disease. To our knowledge, this is the first comprehensive analysis of CLL combining whole-genome sequencing with clinical characteristics and clinical outcomes. It highlights the usefulness of this approach for the identification of clinically relevant mutations in cancer.


Subject(s)
Genome, Human/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Mutation/genetics , Amino Acid Sequence , Animals , Carrier Proteins/genetics , DNA Mutational Analysis , Humans , Karyopherins/genetics , Molecular Sequence Data , Myeloid Differentiation Factor 88/chemistry , Myeloid Differentiation Factor 88/genetics , Receptor, Notch1/genetics , Receptors, Cytoplasmic and Nuclear/genetics , Reproducibility of Results , Exportin 1 Protein
6.
Nucleic Acids Res ; 43(6): 3056-67, 2015 Mar 31.
Article in English | MEDLINE | ID: mdl-25735743

ABSTRACT

Cohesin, which in somatic vertebrate cells consists of SMC1, SMC3, RAD21 and either SA1 or SA2, mediates higher-order chromatin organization. To determine how cohesin contributes to the establishment of tissue-specific transcriptional programs, we compared genome-wide cohesin distribution, gene expression and chromatin architecture in cerebral cortex and pancreas from adult mice. More than one third of cohesin binding sites differ between the two tissues and these show reduced overlap with CCCTC-binding factor (CTCF) and are enriched at the regulatory regions of tissue-specific genes. Cohesin/CTCF sites at active enhancers and promoters contain, at least, cohesin-SA1. Analyses of chromatin contacts at the Protocadherin (Pcdh) and Regenerating islet-derived (Reg) gene clusters, mostly expressed in brain and pancreas, respectively, revealed remarkable differences that correlate with the presence of cohesin. We could not detect significant changes in the chromatin contacts at the Pcdh locus when comparing brains from wild-type and SA1 null embryos. In contrast, reduced dosage of SA1 altered the architecture of the Reg locus and decreased the expression of Reg genes in the pancreas of SA1 heterozygous mice. Given the role of Reg proteins in inflammation, such reduction may contribute to the increased incidence of pancreatic cancer observed in these animals.


Subject(s)
Cell Cycle Proteins/metabolism , Chromatin/metabolism , Chromosomal Proteins, Non-Histone/metabolism , Animals , Binding Sites , CCCTC-Binding Factor , Cadherins/genetics , Cell Cycle Proteins/deficiency , Cell Cycle Proteins/genetics , Cerebral Cortex/metabolism , Chromatin/chemistry , Chromatin/genetics , Chromosomal Proteins, Non-Histone/deficiency , Chromosomal Proteins, Non-Histone/genetics , Gene Expression , Heterozygote , Mice , Mice, Inbred C57BL , Mice, Knockout , Multigene Family , Pancreas/metabolism , Protein Subunits/deficiency , Protein Subunits/genetics , Protein Subunits/metabolism , RNA/genetics , RNA/metabolism , Repressor Proteins/metabolism , Tissue Distribution , Cohesins
7.
EMBO J ; 31(9): 2090-102, 2012 May 02.
Article in English | MEDLINE | ID: mdl-22415368

ABSTRACT

Vertebrates have two cohesin complexes that consist of Smc1, Smc3, Rad21/Scc1 and either SA1 or SA2, but their functional specificity is unclear. Mouse embryos lacking SA1 show developmental delay and die before birth. Comparison of the genome-wide distribution of cohesin in wild-type and SA1-null cells reveals that SA1 is largely responsible for cohesin accumulation at promoters and at sites bound by the insulator protein CTCF. As a consequence, ablation of SA1 alters transcription of genes involved in biological processes related to Cornelia de Lange syndrome (CdLS), a genetic disorder linked to dysfunction of cohesin. We show that the presence of cohesin-SA1 at the promoter of myc and of protocadherin genes positively regulates their expression, a task that cannot be assumed by cohesin-SA2. Lack of SA1 also alters cohesin-binding pattern along some gene clusters and leads to dysregulation of genes within. We hypothesize that impaired cohesin-SA1 function in gene expression underlies the molecular aetiology of CdLS.


Subject(s)
Cell Cycle Proteins/metabolism , Chromosomal Proteins, Non-Histone/metabolism , Embryonic Development , Gene Expression Regulation , Protein Subunits/metabolism , Animals , Cell Cycle Proteins/deficiency , Cell Cycle Proteins/genetics , Chromosomal Proteins, Non-Histone/deficiency , Chromosomal Proteins, Non-Histone/genetics , De Lange Syndrome/genetics , Embryo, Mammalian , Fibroblasts , Mice , Mice, Knockout , Protein Subunits/deficiency , Protein Subunits/genetics , Proto-Oncogene Proteins c-myc/genetics , Cohesins
8.
Blood ; 123(13): 2034-43, 2014 Mar 27.
Article in English | MEDLINE | ID: mdl-24497536

ABSTRACT

Cutaneous T-cell lymphoma (CTCL) is a heterogeneous group of primary cutaneous T-cell lymphoproliferative processes, mainly composed of mycosis fungoides and Sézary syndrome, the aggressive forms of which lack an effective treatment. The molecular pathogenesis of CTCL is largely unknown, although neoplastic cells show increased signaling from T-cell receptors (TCRs). DNAs from 11 patients with CTCL, both normal and tumoral, were target-enriched and sequenced by massive parallel sequencing for a selection of 524 TCR-signaling-related genes. Identified variants were validated by capillary sequencing. Multiple mutations were found that affected several signaling pathways, such as TCRs, nuclear factor κB, or Janus kinase/signal transducer and activator of transcription, but PLCG1 was found to be mutated in 3 samples, 2 of which featured a redundant mutation (c.1034T>C, S345F) in exon 11 that affects the PLCx protein catalytic domain. This mutation was further analyzed by quantitative polymerase chain reaction genotyping in a new cohort of 42 patients with CTCL, where it was found in 19% of samples. Immunohistochemical analysis for nuclear factor of activated T cells (NFAT) showed that PLCG1-mutated cases exhibited strong NFAT nuclear immunostaining. Functional studies demonstrated that PLCG1 mutants elicited increased downstream signaling toward NFAT activation, and inhibition of this pathway resulted in reduced CTCL cell proliferation and cell viability. Thus, increased proliferative and survival mechanisms in CTCL may partially depend on the acquisition of somatic mutations in PLCG1 and other genes that are essential for normal T-cell differentiation.


Subject(s)
Lymphoma, T-Cell/genetics , Mutation , Phospholipase C gamma/genetics , Skin Neoplasms/genetics , Animals , Cell Line, Tumor , Cell Survival/genetics , Cohort Studies , DNA Mutational Analysis , Female , High-Throughput Nucleotide Sequencing , Humans , Lymphoma, T-Cell/pathology , Male , Mice , NIH 3T3 Cells , Skin Neoplasms/pathology
9.
BMC Genomics ; 16: 403, 2015 05 22.
Article in English | MEDLINE | ID: mdl-25997541

ABSTRACT

BACKGROUND: Urothelial bladder cancer is a highly heterogeneous disease. Cancer cell lines are useful tools for its study. This is a comprehensive genomic characterization of 40 urothelial bladder carcinoma (UBC) cell lines including information on origin, mutation status of genes implicated in bladder cancer (FGFR3, PIK3CA, TP53, and RAS), copy number alterations assessed using high density SNP arrays, uniparental disomy (UPD) events, and gene expression. RESULTS: Based on gene mutation patterns and genomic changes we identify lines representative of the FGFR3-driven tumor pathway and of the TP53/RB tumor suppressor-driven pathway. High-density array copy number analysis identified significant focal gains (1q32, 5p13.1-12, 7q11, and 7q33) and losses (i.e. 6p22.1) in regions altered in tumors but not previously described as affected in bladder cell lines. We also identify new evidence for frequent regions of UPD, often coinciding with regions reported to be lost in tumors. Previously undescribed chromosome X losses found in UBC lines also point to potential tumor suppressor genes. Cell lines representative of the FGFR3-driven pathway showed a lower number of UPD events. CONCLUSIONS: Overall, there is a predominance of more aggressive tumor subtypes among the cell lines. We provide a cell line classification that establishes their relatedness to the major molecularly-defined bladder tumor subtypes. The compiled information should serve as a useful reference to the bladder cancer research community and should help to select cell lines appropriate for the functional analysis of bladder cancer genes, for example those being identified through massive parallel sequencing.


Subject(s)
Databases, Genetic , Genome, Human , Urinary Bladder Neoplasms/genetics , Biomarkers, Tumor/genetics , Cell Line, Tumor , Chromosomes, Human, X , Class I Phosphatidylinositol 3-Kinases , Cluster Analysis , DNA Copy Number Variations , Female , Genomic Instability , Humans , Male , Phosphatidylinositol 3-Kinases/genetics , Receptor, Fibroblast Growth Factor, Type 3/genetics , Tumor Suppressor Protein p53/genetics , Urinary Bladder Neoplasms/pathology , ras Proteins/genetics
10.
Int J Cancer ; 136(3): 593-602, 2015 Feb 01.
Article in English | MEDLINE | ID: mdl-24917463

ABSTRACT

Screening for germline mutations in breast cancer-associated genes BRCA1 and BRCA2 is indicated for patients with breast cancer from high-risk breast cancer families and influences both treatment options and clinical management. However, only 25% of selected patients test positive for BRCA1/2 mutation, indicating that additional diagnostic biomarkers are necessary. We analyzed 124 formalin-fixed paraffin-embedded (FFPE) tumor samples from patients with hereditary (104) and sporadic (20) invasive breast cancer, divided into two series (A and B). Microarray expression profiling of 829 human miRNAs was performed on 76 samples (Series A), and bioinformatics tool Prophet was used to develop and test a microarray classifier. Samples were stratified into a training set (n = 38) for microarray classifier generation and a test set (n = 38) for signature validation. A 35-miRNA microarray classifier was generated for the prediction of BRCA1/2 mutation status with a reported 95% (95% CI = 0.88-1.0) and 92% (95% CI: 0.84-1.0) accuracy in the training and the test set, respectively. Differential expression of 12 miRNAs between BRCA1/2 mutation carriers versus noncarriers was validated by qPCR in an independent tumor series B (n = 48). Logistic regression model based on the expression of six miRNAs (miR-142-3p, miR-505*, miR-1248, miR-181a-2*, miR-25* and miR-340*) discriminated between tumors from BRCA1/2 mutation carriers and noncarriers with 92% (95% CI: 0.84-0.99) accuracy. In conclusion, we identified miRNA expression signatures predictive of BRCA1/2 mutation status in routinely available FFPE breast tumor samples, which may be useful to complement current patient selection criteria for gene testing by identifying individuals with high likelihood of being BRCA1/2 mutation carriers.


Subject(s)
Breast Neoplasms/genetics , Genes, BRCA1 , Genes, BRCA2 , MicroRNAs/analysis , Mutation , Female , Formaldehyde , Humans , Logistic Models , Paraffin Embedding
11.
Proc Natl Acad Sci U S A ; 109(26): 10522-7, 2012 Jun 26.
Article in English | MEDLINE | ID: mdl-22689993

ABSTRACT

Human aging cannot be fully understood in terms of the constrained genetic setting. Epigenetic drift is an alternative means of explaining age-associated alterations. To address this issue, we performed whole-genome bisulfite sequencing (WGBS) of newborn and centenarian genomes. The centenarian DNA had a lower DNA methylation content and a reduced correlation in the methylation status of neighboring cytosine--phosphate--guanine (CpGs) throughout the genome in comparison with the more homogeneously methylated newborn DNA. The more hypomethylated CpGs observed in the centenarian DNA compared with the neonate covered all genomic compartments, such as promoters, exonic, intronic, and intergenic regions. For regulatory regions, the most hypomethylated sequences in the centenarian DNA were present mainly at CpG-poor promoters and in tissue-specific genes, whereas a greater level of DNA methylation was observed in CpG island promoters. We extended the study to a larger cohort of newborn and nonagenarian samples using a 450,000 CpG-site DNA methylation microarray that reinforced the observation of more hypomethylated DNA sequences in the advanced age group. WGBS and 450,000 analyses of middle-age individuals demonstrated DNA methylomes in the crossroad between the newborn and the nonagenarian/centenarian groups. Our study constitutes a unique DNA methylation analysis of the extreme points of human life at a single-nucleotide resolution level.


Subject(s)
DNA Methylation , Aged , Aged, 80 and over , Humans , Infant, Newborn
12.
Bioinformatics ; 29(13): 1687-9, 2013 Jul 01.
Article in English | MEDLINE | ID: mdl-23630175

ABSTRACT

MOTIVATION: RUbioSeq has been developed to facilitate the primary and secondary analysis of re-sequencing projects by providing an integrated software suite of parallelized pipelines to detect exome variants (single-nucleotide variants and copy number variations) and to perform bisulfite-seq analyses automatically. RUbioSeq's variant analysis results have been already validated and published. AVAILABILITY: http://rubioseq.sourceforge.net/.


Subject(s)
Exome , Genetic Variation , High-Throughput Nucleotide Sequencing/methods , Sequence Analysis, DNA/methods , Software , Sulfites , DNA Copy Number Variations , DNA Methylation , Humans , Polymorphism, Single Nucleotide
13.
Am J Pathol ; 182(2): 350-62, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23201134

ABSTRACT

Medullary thyroid carcinoma accounts for 2% to 5% of thyroid malignancies, of which 75% are sporadic and the remaining 25% are hereditary and related to multiple endocrine neoplasia type 2 syndrome. Despite a genotype-phenotype correlation with specific germline RET mutations, knowledge of pathways specifically associated with each mutation and with non-RET-mutated sporadic MTC remains lacking. Gene expression patterns have provided a tool for identifying molecular events related to specific tumor types and to different clinical features that could help identify novel therapeutic targets. Using transcriptional profiling of 49 frozen MTC specimens classified as RET mutation, we identified PROM1, LOXL2, GFRA1, and DKK4 as related to RET(M918T) and GAL as related to RET(634) mutation. An independent series of 19 frozen and 23 formalin-fixed, paraffin-embedded (FFPE) MTCs was used for validation by RT-qPCR. Two tissue microarrays containing 69 MTCs were available for IHC assays. According to pathway enrichment analysis and gene ontology biological processes, genes associated with the MTC(M918T) group were involved mainly in proliferative, cell adhesion, and general malignant metastatic effects and with Wnt, Notch, NFκB, JAK/Stat, and MAPK signaling pathways. Assays based on silencing of PROM1 by siRNAs performed in the MZ-CRC-1 cell line, harboring RET(M918T), caused an increase in apoptotic nuclei, suggesting that PROM1 is necessary for survival of these cells. This is the first report of PROM1 overexpression among primary tumors.


Subject(s)
Biomarkers, Tumor/genetics , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Genetic Predisposition to Disease , Thyroid Neoplasms/genetics , AC133 Antigen , Antigens, CD/metabolism , Apoptosis/genetics , Carcinoma, Neuroendocrine , Cell Line, Tumor , Cluster Analysis , Gene Knockdown Techniques , Gene Silencing , Glycoproteins/metabolism , Humans , Immunohistochemistry , Inheritance Patterns/genetics , Peptides/metabolism , RNA, Small Interfering/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Thyroid Neoplasms/pathology
14.
Blood ; 117(23): 6255-66, 2011 Jun 09.
Article in English | MEDLINE | ID: mdl-21478429

ABSTRACT

Many mammalian transcripts contain target sites for multiple miRNAs, although it is not clear to what extent miRNAs may coordinately regulate single genes. We have mapped the interactions between down-regulated miRNAs and overexpressed target protein-coding genes in murine and human lymphomas. Myc, one of the hallmark oncogenes in these lymphomas, stands out as the up-regulated gene with the highest number of genetic interactions with down-regulated miRNAs in mouse lymphomas. The regulation of Myc by several of these miRNAs is confirmed by cellular and reporter assays. The same approach identifies MYC and multiple Myc targets as a preferential target of down-regulated miRNAs in human Burkitt lymphoma, a pathology characterized by translocated MYC oncogenes. These results indicate that several miRNAs must be coordinately down-regulated to enhance critical oncogenes, such as Myc. Some of these Myc-targeting miRNAs are repressed by Myc, suggesting that these tumors are a consequence of the unbalanced activity of Myc versus miRNAs.


Subject(s)
Burkitt Lymphoma/metabolism , Gene Expression Regulation, Neoplastic , MicroRNAs/metabolism , Proto-Oncogene Proteins c-myc/biosynthesis , RNA, Neoplasm/metabolism , Animals , Burkitt Lymphoma/genetics , Cell Line, Tumor , Female , Humans , Male , MicroRNAs/genetics , Proto-Oncogene Proteins c-myc/genetics , RNA, Neoplasm/genetics
15.
Blood ; 118(4): 1034-40, 2011 Jul 28.
Article in English | MEDLINE | ID: mdl-21633089

ABSTRACT

Diffuse large B-cell lymphoma (DLBCL) prognostication requires additional biologic markers. miRNAs may constitute markers for cancer diagnosis, outcome, or therapy response. In the present study, we analyzed the miRNA expression profile in a retrospective multicenter series of 258 DLBCL patients uniformly treated with chemoimmunotherapy. Findings were correlated with overall survival (OS) and progression-free survival (PFS). miRNA and gene-expression profiles were studied using microarrays in an initial set of 36 cases. A selection of miRNAs associated with either DLBCL molecular subtypes (GCB/ABC) or clinical outcome were studied by multiplex RT-PCR in a test group of 240 cases with available formalin-fixed, paraffin-embedded (FFPE) diagnostic samples. The samples were divided into a training set (123 patients) and used to derive miRNA-based and combined (with IPI score) Cox regression models in an independent validation series (117 patients). Our model based on miRNA expression predicts OS and PFS and improves upon the predictions based on clinical variables. Combined models with IPI score identified a high-risk group of patients with a 2-year OS and a PFS probability of < 50%. In summary, a precise miRNA signature is associated with poor clinical outcome in chemoimmunotherapy-treated DLBCL patients. This information improves upon IPI-based predictions and identifies a subgroup of candidate patients for alternative therapeutic regimens.


Subject(s)
Biomarkers, Tumor/genetics , Lymphoma, Large B-Cell, Diffuse/genetics , MicroRNAs/biosynthesis , Antineoplastic Agents/therapeutic use , Disease-Free Survival , Female , Gene Expression , Gene Expression Profiling , Humans , Immunohistochemistry , Immunotherapy , Kaplan-Meier Estimate , Lymphoma, Large B-Cell, Diffuse/drug therapy , Lymphoma, Large B-Cell, Diffuse/mortality , Male , Microarray Analysis , Middle Aged , Neoplasm Staging , Prognosis , Proportional Hazards Models , Retrospective Studies , Reverse Transcriptase Polymerase Chain Reaction , Tissue Array Analysis
16.
Nucleic Acids Res ; 39(Web Server issue): W562-6, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21646339

ABSTRACT

Next-generation sequencing (NGS) technologies are making sequence data available on an unprecedented scale. In this context, new catalogs of Single Nucleotide Polymorphism and mutations generated by resequencing studies are usually stored in genome position files (e.g. Variant Call Format, SAMTools pileup, BED, GFF) comprising of large lists of genomic positions, which are difficult to handle by researchers. Here, we present PileLineGUI, a novel desktop application primarily designed for manipulating, browsing and analysing genome position files (GPF), with specific support to somatic mutation finding studies. The developed tool also integrates a new genome browser module specially designed for inspecting GPFs. PileLineGUI is free, multiplatform and designed to be intuitively used by biomedical researchers. PileLineGUI is available at: http://sing.ei.uvigo.es/pileline/pilelinegui.html.


Subject(s)
Genome , High-Throughput Nucleotide Sequencing , Sequence Analysis, DNA , Software , Mutation , Polymorphism, Single Nucleotide
17.
BMC Genomics ; 13: 147, 2012 Apr 24.
Article in English | MEDLINE | ID: mdl-22531031

ABSTRACT

BACKGROUND: The transcription factor Pax8 is essential for the differentiation of thyroid cells. However, there are few data on genes transcriptionally regulated by Pax8 other than thyroid-related genes. To better understand the role of Pax8 in the biology of thyroid cells, we obtained transcriptional profiles of Pax8-silenced PCCl3 thyroid cells using whole genome expression arrays and integrated these signals with global cis-regulatory sequencing studies performed by ChIP-Seq analysis RESULTS: Exhaustive analysis of Pax8 immunoprecipitated peaks demonstrated preferential binding to intragenic regions and CpG-enriched islands, which suggests a role of Pax8 in transcriptional regulation of orphan CpG regions. In addition, ChIP-Seq allowed us to identify Pax8 partners, including proteins involved in tertiary DNA structure (CTCF) and chromatin remodeling (Sp1), and these direct transcriptional interactions were confirmed in vivo. Moreover, both factors modulate Pax8-dependent transcriptional activation of the sodium iodide symporter (Nis) gene promoter. We ultimately combined putative and novel Pax8 binding sites with actual target gene expression regulation to define Pax8-dependent genes. Functional classification suggests that Pax8-regulated genes may be directly involved in important processes of thyroid cell function such as cell proliferation and differentiation, apoptosis, cell polarity, motion and adhesion, and a plethora of DNA/protein-related processes. CONCLUSION: Our study provides novel insights into the role of Pax8 in thyroid biology, exerted through transcriptional regulation of important genes involved in critical thyrocyte processes. In addition, we found new transcriptional partners of Pax8, which functionally cooperate with Pax8 in the regulation of thyroid gene transcription. Besides, our data demonstrate preferential location of Pax8 in non-promoter CpG regions. These data point to an orphan CpG island-mediated mechanism that represents a novel role of Pax8 in the transcriptional output of the thyrocyte.


Subject(s)
Genome , Paired Box Transcription Factors/genetics , Thyroid Gland/metabolism , Animals , Binding Sites , CCCTC-Binding Factor , Cell Differentiation , Cell Line , Chromatin Immunoprecipitation , CpG Islands , Gene Expression Regulation , Gene Silencing , Genome-Wide Association Study , HeLa Cells , Humans , Microarray Analysis , PAX8 Transcription Factor , Paired Box Transcription Factors/antagonists & inhibitors , Paired Box Transcription Factors/metabolism , Promoter Regions, Genetic , RNA Interference , RNA, Small Interfering/metabolism , Rats , Repressor Proteins/genetics , Repressor Proteins/metabolism , Sp1 Transcription Factor/genetics , Sp1 Transcription Factor/metabolism , Symporters/genetics , Symporters/metabolism , Thyroid Gland/cytology , Transfection
18.
Biochem J ; 434(3): 549-58, 2011 Mar 15.
Article in English | MEDLINE | ID: mdl-21226672

ABSTRACT

p38α MAPK (mitogen-activated protein kinase) plays an important tumour suppressor role, which is mediated by both its negative effect on cell proliferation and its pro-apoptotic activity. Surprisingly, most tumour suppressor mechanisms co-ordinated by p38α have been reported to occur at the post-translational level. This contrasts with the important role of p38α in the regulation of transcription and the profound changes in gene expression that normally occur during tumorigenesis. We have analysed whole-genome expression profiles of Ras-transformed wild-type and p38α-deficient cells and have identified 202 genes that are potentially regulated by p38α in transformed cells. Expression analysis has confirmed the regulation of these genes by p38α in tumours, and functional validation has identified several of them as probable mediators of the tumour suppressor effect of p38α on Ras-induced transformation. Interestingly, approx. 10% of the genes that are negatively regulated by p38α in transformed cells contribute to EGF (epidermal growth factor) receptor signalling. Our results suggest that inhibition of EGF receptor signalling by transcriptional targets of p38α is an important function of this signalling pathway in the context of tumour suppression.


Subject(s)
Cell Transformation, Neoplastic/metabolism , Mitogen-Activated Protein Kinase 14/physiology , Transcription, Genetic , Animals , Cell Proliferation , Cell Transformation, Neoplastic/pathology , Cells, Cultured , ErbB Receptors/physiology , Fibroblasts/metabolism , Fibroblasts/pathology , Gene Expression Profiling , Genes, ras , Humans , Mice , Mice, Nude , Mitogen-Activated Protein Kinase 14/genetics , Neoplasm Transplantation , Oligonucleotide Array Sequence Analysis , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction
19.
Nucleic Acids Res ; 38(Web Server issue): W182-7, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20507915

ABSTRACT

waviCGH is a versatile web server for the analysis and comparison of genomic copy number alterations in multiple samples from any species. waviCGH processes data generated by high density SNP-arrays, array-CGH or copy-number calls generated by any technique. waviCGH includes methods for pre-processing of the data, segmentation, calling of gains and losses, and minimal common regions determination over a set of experiments. The server is a user-friendly interface to the analytical methods, with emphasis on results visualization in a genomic context. Analysis tools are introduced to the user as the different steps to follow in an experimental protocol. All the analysis steps generate high quality images and tables ready to be imported into spreadsheet programs. Additionally, for human, mouse and rat, altered regions are represented in a biological context by mapping them into chromosomes in an integrated cytogenetic browser. waviCGH is available at http://wavi.bioinfo.cnio.es.


Subject(s)
Comparative Genomic Hybridization , DNA Copy Number Variations , Oligonucleotide Array Sequence Analysis , Software , Animals , Genomics , Humans , Internet , Mice , Rats
20.
Nucleic Acids Res ; 38(Web Server issue): W683-8, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20462862

ABSTRACT

The EMBRACE (European Model for Bioinformatics Research and Community Education) web service collection is the culmination of a 5-year project that set out to investigate issues involved in developing and deploying web services for use in the life sciences. The project concluded that in order for web services to achieve widespread adoption, standards must be defined for the choice of web service technology, for semantically annotating both service function and the data exchanged, and a mechanism for discovering services must be provided. Building on this, the project developed: EDAM, an ontology for describing life science web services; BioXSD, a schema for exchanging data between services; and a centralized registry (http://www.embraceregistry.net) that collects together around 1000 services developed by the consortium partners. This article presents the current status of the collection and its associated recommendations and standards definitions.


Subject(s)
Computational Biology , Software , Biological Science Disciplines , Information Dissemination , Internet , Registries , Systems Integration
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