73 research outputs found
Telomerase promoter mutations in cancer: an emerging molecular biomarker?
João Vinagre, Vasco Pinto and Ricardo Celestino contributed equally to
the manuscript.Cell immortalization has been considered for a long time as a classic hallmark of cancer cells. Besides telomerase reactivation, such immortalization could be due to telomere maintenance through the “alternative mechanism of telomere lengthening” (ALT) but the mechanisms underlying both forms of reactivation remained elusive. Mutations in the coding region of telomerase gene are very rare in the cancer setting, despite being associated with some degenerative diseases. Recently, mutations in telomerase (TERT) gene promoter were found in sporadic and familial melanoma and subsequently in several cancer models, notably in gliomas, thyroid cancer and bladder cancer. The importance of these findings has been reinforced by the association of TERT mutations in some cancer types with tumour aggressiveness and patient survival. In the first part of this review, we summarize the data on the biology of telomeres and telomerase, available methodological approaches and non-neoplastic diseases associated with telomere dysfunction. In the second part, we review the information on telomerase expression and genetic alterations in the most relevant types of cancer (skin, thyroid, bladder and central nervous system) on record, and discuss the value of telomerase as a new biomarker with impact on the prognosis and survival of the patients and as a putative therapeutic target
Sequence variants associating with urinary biomarkers
Urine dipstick tests are widely used in routine medical care to diagnose kidney and urinary tract and metabolic diseases. Several environmental factors are known to affect the test results, whereas the effects of genetic diversity are largely unknown. We tested 32.5 million sequence variants for association with urinary biomarkers in a set of 150 274 Icelanders with urine dipstick measurements. We detected 20 association signals, of which 14 are novel, associating with at least one of five clinical entities defined by the urine dipstick: glucosuria, ketonuria, proteinuria, hematuria and urine pH. These include three independent glucosuria variants at SLC5A2, the gene encoding the sodium-dependent glucose transporter (SGLT2), a protein targeted pharmacologically to increase urinary glucose excretion in the treatment of diabetes. Two variants associating with proteinuria are in LRP2 and CUBN, encoding the co-transporters megalin and cubilin, respectively, that mediate proximal tubule protein uptake. One of the hematuria-associated variants is a rare, previously unreported 2.5 kb exonic deletion in COL4A3. Of the four signals associated with urine pH, we note that the pH-increasing alleles of two variants (POU2AF1, WDR72) associate significantly with increased risk of kidney stones. Our results reveal that genetic factors affect variability in urinary biomarkers, in both a disease dependent and independent context
Loss-of-function mutations in SLC30A8 protect against type 2 diabetes.
Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenLoss-of-function mutations protective against human disease provide in vivo validation of therapeutic targets, but none have yet been described for type 2 diabetes (T2D). Through sequencing or genotyping of ~150,000 individuals across 5 ancestry groups, we identified 12 rare protein-truncating variants in SLC30A8, which encodes an islet zinc transporter (ZnT8) and harbors a common variant (p.Trp325Arg) associated with T2D risk and glucose and proinsulin levels. Collectively, carriers of protein-truncating variants had 65% reduced T2D risk (P = 1.7 × 10(-6)), and non-diabetic Icelandic carriers of a frameshift variant (p.Lys34Serfs*50) demonstrated reduced glucose levels (-0.17 s.d., P = 4.6 × 10(-4)). The two most common protein-truncating variants (p.Arg138* and p.Lys34Serfs*50) individually associate with T2D protection and encode unstable ZnT8 proteins. Previous functional study of SLC30A8 suggested that reduced zinc transport increases T2D risk, and phenotypic heterogeneity was observed in mouse Slc30a8 knockouts. In contrast, loss-of-function mutations in humans provide strong evidence that SLC30A8 haploinsufficiency protects against T2D, suggesting ZnT8 inhibition as a therapeutic strategy in T2D prevention.US National Institutes of Health (NIH) Training
5-T32-GM007748-33
Doris Duke Charitable Foundation
2006087
Fulbright Diabetes UK Fellowship
BDA 11/0004348
Broad Institute from Pfizer, Inc.
NIH
U01 DK085501
U01 DK085524
U01 DK085545
U01 DK085584
Swedish Research Council
Dnr 521-2010-3490
Dnr 349-2006-237
European Research Council (ERC)
GENETARGET T2D
GA269045
ENGAGE
2007-201413
CEED3
2008-223211
Sigrid Juselius Foundation
Folkh lsan Research Foundation
ERC
AdG 293574
Research Council of Norway
197064/V50
KG Jebsen Foundation
University of Bergen
Western Norway Health Authority
Lundbeck Foundation
Novo Nordisk Foundation
Wellcome Trust
WT098017
WT064890
WT090532
WT090367
WT098381
Uppsala University
Swedish Research Council and the Swedish Heart- Lung Foundation
Academy of Finland
124243
102318
123885
139635
Finnish Heart Foundation
Finnish Diabetes Foundation, Tekes
1510/31/06
Commission of the European Community
HEALTH-F2-2007-201681
Ministry of Education and Culture of Finland
European Commission Framework Programme 6 Integrated Project
LSHM-CT-2004-005272
City of Kuopio and Social Insurance Institution of Finland
Finnish Foundation for Cardiovascular Disease
NIH/NIDDK
U01-DK085545
National Heart, Lung, and Blood Institute (NHLBI)
National Institute on Minority Health and Health Disparities
N01 HC-95170
N01 HC-95171
N01 HC-95172
European Union Seventh Framework Programme, DIAPREPP
Swedish Child Diabetes Foundation (Barndiabetesfonden)
5U01DK085526
DK088389
U54HG003067
R01DK072193
R01DK062370
Z01HG000024info:eu-repo/grantAgreement/EC/FP7/20201
Genetic fine mapping and genomic annotation defines causal mechanisms at type 2 diabetes susceptibility loci.
We performed fine mapping of 39 established type 2 diabetes (T2D) loci in 27,206 cases and 57,574 controls of European ancestry. We identified 49 distinct association signals at these loci, including five mapping in or near KCNQ1. 'Credible sets' of the variants most likely to drive each distinct signal mapped predominantly to noncoding sequence, implying that association with T2D is mediated through gene regulation. Credible set variants were enriched for overlap with FOXA2 chromatin immunoprecipitation binding sites in human islet and liver cells, including at MTNR1B, where fine mapping implicated rs10830963 as driving T2D association. We confirmed that the T2D risk allele for this SNP increases FOXA2-bound enhancer activity in islet- and liver-derived cells. We observed allele-specific differences in NEUROD1 binding in islet-derived cells, consistent with evidence that the T2D risk allele increases islet MTNR1B expression. Our study demonstrates how integration of genetic and genomic information can define molecular mechanisms through which variants underlying association signals exert their effects on disease
An Expanded Genome-Wide Association Study of Type 2 Diabetes in Europeans.
To characterize type 2 diabetes (T2D)-associated variation across the allele frequency spectrum, we conducted a meta-analysis of genome-wide association data from 26,676 T2D case and 132,532 control subjects of European ancestry after imputation using the 1000 Genomes multiethnic reference panel. Promising association signals were followed up in additional data sets (of 14,545 or 7,397 T2D case and 38,994 or 71,604 control subjects). We identified 13 novel T2D-associated loci (P < 5 × 10(-8)), including variants near the GLP2R, GIP, and HLA-DQA1 genes. Our analysis brought the total number of independent T2D associations to 128 distinct signals at 113 loci. Despite substantially increased sample size and more complete coverage of low-frequency variation, all novel associations were driven by common single nucleotide variants. Credible sets of potentially causal variants were generally larger than those based on imputation with earlier reference panels, consistent with resolution of causal signals to common risk haplotypes. Stratification of T2D-associated loci based on T2D-related quantitative trait associations revealed tissue-specific enrichment of regulatory annotations in pancreatic islet enhancers for loci influencing insulin secretion and in adipocytes, monocytes, and hepatocytes for insulin action-associated loci. These findings highlight the predominant role played by common variants of modest effect and the diversity of biological mechanisms influencing T2D pathophysiology.Please refer to the manuscript or visit the publisher's website for funding infomation
Large-scale association analysis provides insights into the genetic architecture and pathophysiology of type 2 diabetes
To extend understanding of the genetic architecture and molecular basis of type 2 diabetes (T2D), we conducted a meta-analysis of genetic variants on the Metabochip involving 34,840 cases and 114,981 controls, overwhelmingly of European descent. We identified ten previously unreported T2D susceptibility loci, including two demonstrating sex-differentiated association. Genome-wide analyses of these data are consistent with a long tail of further common variant loci explaining much of the variation in susceptibility to T2D. Exploration of the enlarged set of susceptibility loci implicates several processes, including CREBBP-related transcription, adipocytokine signalling and cell cycle regulation, in diabetes pathogenesis
A syndrome of progressive pancytopenia with microcephaly, cerebellar hypoplasia and growth failure
To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldA male infant with congenital thrombocytopenia, progressing to pancytopenia in the second year of life is presented. Other findings included microcephaly with cerebellar hypoplasia, growth failure of prenatal onset and severe psychomotor retardation. He died at 23 months of age from candida albicans septicemia. Laboratory studies and a postmortem examination failed to reveal any known etiology for his disorder, but parental consanguinity suggests a genetic basis with an autosomal recessive mode of inheritance. Høyeraal et al. have previously reported two brothers with similar clinical and laboratory findings. It is proposed that the condition of these three patients should be considered as a separate syndrome of congenital pancytopenia, distinguished from other congenital myeloid dysplasias by the extramedullary findings
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