Background information. MYG1 Melanocyte proliferating gene 1, also known as Gamm1 (NM_021640) is a recently described gene of unknown function. MYG1 orthologues are found in simple as well as complex ...eukaryotes. According to sequence homology, MYG1 is considered to have a metal‐dependent protein hydrolase (UPF0160) domain. The purpose of the present study was to determine the expression and subcellular localization of MYG1 protein and to identify physiological processes connected to MYG1 function.
Results. Human and mouse MYG1 is ubiquitously expressed, with the highest level in the testis. Analysis of mouse embryos moreover revealed a uniform Myg1 expression at E (embryonic day) 8.5, but at E11.75 expression becomes restricted predominantly to the developing brain and eye, limb buds and tail region. MYG1 exhibits a mitochondrial targeting signal in the N‐terminal region and a Pat7‐type nuclear localization signal in the region between amino acids 33–39 and localizes to these compartments. No active shuttling of MYG1 between the nucleus and the mitochondria was detected and the distribution of MYG1 was not dependent on the phase of the cell cycle. Immunoprecipitation of C‐terminally FLAG‐tagged MYG1 from HeLa cells did not identify any co‐precipitated proteins. siRNA (short interfering RNA)‐mediated knockdown of MYG1 mRNA was mainly followed by changes in the level of transcripts encoding factors involved in developmental tissue patterning and growth as well as immune‐related processes.
Conclusions. Taken together, we infer that MYG1 is a ubiquitous nucleo‐mitochondrial protein, with differential pattern and level of expression during embryonic development. MYG1 expression in normal adult tissues is stable and our data suggest MYG1 involvement in early developmental processes and also in adult stress/illness conditions.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Genome-wide association studies (GWAS) have identified 12 epithelial ovarian cancer (EOC) susceptibility alleles. The pattern of association at these loci is consistent in BRCA1 and BRCA2 mutation ...carriers who are at high risk of EOC. After imputation to 1000 Genomes Project data, we assessed associations of 11 million genetic variants with EOC risk from 15,437 cases unselected for family history and 30,845 controls and from 15,252 BRCA1 mutation carriers and 8,211 BRCA2 mutation carriers (3,096 with ovarian cancer), and we combined the results in a meta-analysis. This new study design yielded increased statistical power, leading to the discovery of six new EOC susceptibility loci. Variants at 1p36 (nearest gene, WNT4), 4q26 (SYNPO2), 9q34.2 (ABO) and 17q11.2 (ATAD5) were associated with EOC risk, and at 1p34.3 (RSPO1) and 6p22.1 (GPX6) variants were specifically associated with the serous EOC subtype, all with P < 5 × 10(-8). Incorporating these variants into risk assessment tools will improve clinical risk predictions for BRCA1 and BRCA2 mutation carriers.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Germ-line mutations in the tumour suppressor proteins and predispose to breast and ovarian cancer. We have recently identified a Greenlandic Inuit nucleotide 234T>G/c.115T>G (p.Cys39Gly) founder ...mutation, which at that time was the only disease-causing mutation identified in this population. Here, we describe the identification of a novel disease-causing nucleotide 4803delCC/c.4684delCC mutation in a Greenlandic Inuit with ovarian cancer. The mutation introduces a frameshift and a premature stop at codon 1572. We have also identified a nucleotide 249T>A/c.130T>A (p.Cys44Ser) mutation in another Greenlandic individual with ovarian cancer. This patient share a 1–2 Mb genomic fragment, containing the gene, with four Danish families harbouring the same mutation, suggesting that the 249T>A/c.130T>A (p.Cys44Ser) mutation originates from a Danish ancestor. We conclude that screening of Greenlandic Inuits with high risk of breast or ovarian cancer should include sequencing of the entire gene.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Single Nucleotide Polymorphisms (SNPs) in genes involved in the DNA Base Excision Repair (BER) pathway could be associated with cancer risk in carriers of mutations in the high-penetrance ...susceptibility genes BRCA1 and BRCA2, given the relation of synthetic lethality that exists between one of the components of the BER pathway, PARP1 (poly ADP ribose polymerase), and both BRCA1 and BRCA2. In the present study, we have performed a comprehensive analysis of 18 genes involved in BER using a tagging SNP approach in a large series of BRCA1 and BRCA2 mutation carriers. 144 SNPs were analyzed in a two stage study involving 23,463 carriers from the CIMBA consortium (the Consortium of Investigators of Modifiers of BRCA1 and BRCA2). Eleven SNPs showed evidence of association with breast and/or ovarian cancer at p<0.05 in the combined analysis. Four of the five genes for which strongest evidence of association was observed were DNA glycosylases. The strongest evidence was for rs1466785 in the NEIL2 (endonuclease VIII-like 2) gene (HR: 1.09, 95% CI (1.03-1.16), p = 2.7×10-3) for association with breast cancer risk in BRCA2 mutation carriers, and rs2304277 in the OGG1 (8-guanine DNA glycosylase) gene, with ovarian cancer risk in BRCA1 mutation carriers (HR: 1.12 95%CI: 1.03-1.21, p = 4.8×10-3). DNA glycosylases involved in the first steps of the BER pathway may be associated with cancer risk in BRCA1/2 mutation carriers and should be more comprehensively studied.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
germ-line mutations predispose to breast and ovarian cancer. Large genomic rearrangements of account for 0–36% of all disease causing mutations in various populations, while large genomic ...rearrangements in are more rare. We examined 642 East Danish breast and/or ovarian cancer patients in whom a deleterious mutation in and was not detected by sequencing using the multiplex ligation-dependent probe amplification (MLPA) assay. We identified 15 patients with 7 different genomic rearrangements, including a exon 5–7 deletion with a novel breakpoint, a exon 13 duplication, a exon 17–19 deletion, a exon 3–16 deletion, and a exon 20 deletion with a novel breakpoint as well as two novel exon 17–18 and exon 19 deletions. The large rearrangements in and accounted for 9.2% (15/163) of all and mutations in East Denmark. Nine patients had the exon 3–16 deletion in . By SNP analysis we find that the patients share a 5 Mb fragment of chromosome 17, including , indicating that the exon 3–16 deletion represents a Danish founder mutation.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Germ-line mutations in predispose to breast and ovarian cancer. Mutations are widespread throughout the gene and include disease-causing mutations as frameshift, nonsense, splicing mutations and ...large genomic rearrangements. However a large number of mutations, including missense, silent and intron variants are of unknown significance. Here, we describe the functional characterization of a silent mutation (nucleotide 744 G → A/c.516 G → A, Lys172Lys) in exon 6 of in a Danish family with breast and ovarian cancer. Exon trapping analysis showed that the mutation results in skipping of exon 6 and/or both exon 5 and 6, which was verified by RT-PCR analysis on RNA isolated from whole blood of the affected patient. We therefore conclude that the silent mutation Lys172Lys is a disease-causing mutation.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers ...(of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7×10-8, HR = 1.14, 95% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4×10-8, HR = 1.27, 95% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4×10-8, HR = 1.20, 95% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific association. The 17q21.31 locus was also associated with ovarian cancer risk in 8,211 BRCA2 carriers (P = 2×10-4). These loci may lead to an improved understanding of the etiology of breast and ovarian tumors in BRCA1 carriers. Based on the joint distribution of the known BRCA1 breast cancer risk-modifying loci, we estimated that the breast cancer lifetime risks for the 5% of BRCA1 carriers at lowest risk are 28%-50% compared to 81%-100% for the 5% at highest risk. Similarly, based on the known ovarian cancer risk-modifying loci, the 5% of BRCA1 carriers at lowest risk have an estimated lifetime risk of developing ovarian cancer of 28% or lower, whereas the 5% at highest risk will have a risk of 63% or higher. Such differences in risk may have important implications for risk prediction and clinical management for BRCA1 carriers.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Germ-line mutations in the tumour suppressor proteins and predispose to breast and ovarian cancer. We examined 32 breast and/or ovarian cancer patients from Greenland for mutations in and . Whereas ...no mutations were identified in 19 families, 13 families exhibited a exon 3 nucleotide 234 T > G mutation, which has not previously been reported in the breast cancer information core (BIC) database. The mutation changes a conserved cysteine 39 to a glycine in the Zn site II of the RING domain, which is essential for BRCA1 ubiquitin ligase activity. Eight of the families had members with ovarian cancer, suggesting that the RING domain may be an ovarian cancer hotspot. By SNP array analysis, we find that all 13 families share a 4.5 Mb genomic fragment containing the gene, showing that the mutation originates from a founder. Finally, analysis of 1152 Inuit, representing almost ~2% of the total Greenlandic Inuit population, showed that the frequency of the mutation was 1.0%. We conclude that the nucleotide 234 T > G is a common Greenlandic Inuit founder mutation. The relative high frequency in the general population, together with the ease of screening and possibility to reduce mortality in gene carriers, may warrant screening of the Greenlandic Inuit population. Provided screening is efficient, about 5% of breast- and 13% of ovarian cancers, respectively, may be prevented.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The vertebrate neuroendocrine peptide cholecystokinin (CCK) is subjected to numerous post-translational modifications upon maturation to bioactive CCK. However, the current knowledge of the ...proteolytic processing of proCCK, as reviewed here, is not complete. We have chosen Saccharomyces cerevisiae as a model to study these endoproteolytic processing events. Expression of proCCK as a fusion protein to the prepro leader peptide of f -mating factor directed the protein through the secretory pathway and resulted in nanomolar concentrations of secreted glycine-extended CCK. The CCK peptides showed many correlations to the known endoproteolytic processing products of proCCK in endocrine cells. Especially the processing to the abundant form, CCK-22, was investigated and it is suggested that a novel enzyme is responsible for its production. Thus, yeast may be used to study the proteolysis of proCCK with the aim to identify mammalian homologues involved in maturation of CCK.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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