Jansen J.C.,Radboud University Nijmegen |
Cirak S.,Institute For Humangenetik |
Van Scherpenzeel M.,Radboud University Nijmegen |
Van Scherpenzeel M.,Donders Institute for Brain |
And 41 more authors.
American Journal of Human Genetics | Year: 2016
Disorders of Golgi homeostasis form an emerging group of genetic defects. The highly heterogeneous clinical spectrum is not explained by our current understanding of the underlying cell-biological processes in the Golgi. Therefore, uncovering genetic defects and annotating gene function are challenging. Exome sequencing in a family with three siblings affected by abnormal Golgi glycosylation revealed a homozygous missense mutation, c.92T>C (p.Leu31Ser), in coiled-coil domain containing 115 (CCDC115), the function of which is unknown. The same mutation was identified in three unrelated families, and in one family it was compound heterozygous in combination with a heterozygous deletion of CCDC115. An additional homozygous missense mutation, c.31G>T (p.Asp11Tyr), was found in a family with two affected siblings. All individuals displayed a storage-disease-like phenotype involving hepatosplenomegaly, which regressed with age, highly elevated bone-derived alkaline phosphatase, elevated aminotransferases, and elevated cholesterol, in combination with abnormal copper metabolism and neurological symptoms. Two individuals died of liver failure, and one individual was successfully treated by liver transplantation. Abnormal N- and mucin type O-glycosylation was found on serum proteins, and reduced metabolic labeling of sialic acids was found in fibroblasts, which was restored after complementation with wild-type CCDC115. PSI-BLAST homology detection revealed reciprocal homology with Vma22p, the yeast V-ATPase assembly factor located in the endoplasmic reticulum (ER). Human CCDC115 mainly localized to the ERGIC and to COPI vesicles, but not to the ER. These data, in combination with the phenotypic spectrum, which is distinct from that associated with defects in V-ATPase core subunits, suggest a more general role for CCDC115 in Golgi trafficking. Our study reveals CCDC115 deficiency as a disorder of Golgi homeostasis that can be readily identified via screening for abnormal glycosylation in plasma. © 2016 by The American Society of Human Genetics. All rights reserved. Source
Schmidt-Hieber M.,Oncology and Transfusion Medicine |
Blau I.W.,Oncology and Transfusion Medicine |
Richter G.,Oncology and Transfusion Medicine |
Turkmen S.,Institute for Medical Genetics |
And 7 more authors.
Cancer Genetics and Cytogenetics | Year: 2010
We analyzed karyotype stability in 22 patients with acute leukemia at relapse or disease progression after allogeneic stem cell transplantation (allo-SCT). Karyotypes before and at relapse after allo-SCT were different in 15 patients (68%), the most frequent type being clonal evolution either alone or combined with clonal devolution (13 patients). Patients with and without a karyotype change did not differ significantly in overall survival (OS) (median, 399 vs. 452 days; P = 0.889) and survival after relapse (median, 120 vs. 370 days; P = 0.923). However, acquisition of additional structural chromosome 1 abnormalities at relapse after allo-SCT occurred more frequently than expected and was associated with reduced OS (median, 125 vs. 478 days; P = 0.008) and shorter survival after relapse (median, 37 vs. 370 days; P = 0.002). We identified a previously undescribed clonal evolution involving t(15;17) without PML-RARA rearrangement in an AML patient. We conclude that a karyotype change is common at relapse after allo-SCT in acute leukemia patients. Moreover, our data suggest that additional structural chromosome 1 abnormalities are overrepresented at relapse after allo-SCT in these patients and, in contrast to a karyotype change per se, are associated with reduced OS and shorter survival after relapse. © 2010 Elsevier Inc. Source
CRISPR/Cas9 opens up many possibilities in medicine presenting opportunities and risks. It is hoped that the new method can be used for the genetic treatment of serious diseases, such as AIDS. Scientists could simply cut out a gene modified by disease in the body cells and replace it with a healthy one. Scientists in China and the UK are taking this a step further by conducting research in the laboratory using human embryonic stem cells. This has broken a taboo sparking outrage and debate worldwide. How far should research go? Stefan Mundlos, Director of the Institute for Medical Genetics and Human Genetics at the Charité and Research Group Leader at the Max Planck Institute for Molecular Genetics in Berlin, holds a very critical view of interventions in the human germline. The genetic make-up of human embryos can be modified using CRISPR/Cas. What benefits do scientists hope this research will bring? In my view, there is no medical indication for such research. Correcting genetic diseases at the embryo's stem cell stage is a purely theoretical possibility. Establishing this procedure would certainly not only involve huge costs but would also be superfluous, as embryos can already be tested for mutations as part of pre-implantation diagnostics. Only the healthy ones would then be placed in the womb. The manipulation of embryonic stem cells also has far-reaching implications, as all of the organism's cells will then subsequently carry this change. In addition, it involves intervening in the germline, which means the modified gene is passed onto future generations through ovum and sperm cells. Such research is prohibited in Germany by the Embryo Protection Act. Do you envisage this law being softened as in the United Kingdom? First of all, while human embryos are indeed being manipulated in the UK, they are not used for implantation. That would also be illegal there. The experiments currently being performed involve pure basic research. Scientists are seeking to discover which genes play a key role in the early development of the human embryo. Whether such research produces significant gains in scientific knowledge is highly contentious. And there are of course risks too, as the technology being developed essentially paves the way for medical application. I can't imagine such research being carried out in Germany. There is clearly no medical indication for manipulating embryonic stem cells, and such research should not therefore be authorized in my view. So where do you believe the benefits of CRISPR/Cas lie? It provides incredible potential for basic research. By recreating modifications in the genome, the influence of individual genes on the organism can be tested, for example. This is also where I believe the greatest potential for application lies. The major advancement achieved by this technology is the capability to change the genome with a high degree of precision. CRISPR/Cas enables targeted mutations and modifications to be made to a cell or organism and even allows new parts to be inserted. CRISPR/Cas also opens up new opportunities in gene therapy in humans. How does that work exactly? Gene therapy always concerns diseases caused by mutated or altered genes. Diseased cells are removed from the patient, for example from the blood. These are genetically modified in the test tube so that pathogenic mutation is corrected and then put back into the patient's blood. Such modification cannot be inherited, as no other cells – in particular ovum and semen cells – are affected. What benefits does CRISPR/Cas offer for gene therapy? Virus systems have thus far been used to make genomic modifications. An artificial virus infects the cells and implants the DNA fragments. The gene encoded in the fragments is precisely the one changing in the patient and which therefore no longer works properly. The healthy gene is then incorporated into the patient's genetic make-up. Virus systems nevertheless have a major disadvantage: they insert the healthy gene into the genome randomly. This often causes problems, because if the gene ends up in the wrong place it can result in cell degeneration and the onset of cancer. Genetic treatment is therefore not used routinely at the moment. Being able to insert the healthy gene with great precision – as is possible with CRISPR/Cas technology – would represent major progress. Even though CRISPR/Cas is still in its infancy, this treatment is expected to be available in the not too distant future. Explore further: A CRISPR way to edit DNA
Leushacke M.,Max Planck Institute for Molecular Genetics |
Leushacke M.,Free University of Berlin |
Sporle R.,Max Planck Institute for Molecular Genetics |
Bernemann C.,Max Planck Institute for Molecular Genetics |
And 10 more authors.
PLoS ONE | Year: 2011
In tumor cells, stepwise oncogenic deregulation of signaling cascades induces alterations of cellular morphology and promotes the acquisition of malignant traits. Here, we identified a set of 21 genes, including FGF9, as determinants of tumor cell morphology by an RNA interference phenotypic screen in SW480 colon cancer cells. Using a panel of small molecular inhibitors, we subsequently established phenotypic effects, downstream signaling cascades, and associated gene expression signatures of FGF receptor signals. We found that inhibition of FGF signals induces epithelial cell adhesion and loss of motility in colon cancer cells. These effects are mediated via the mitogen-activated protein kinase (MAPK) and Rho GTPase cascades. In agreement with these findings, inhibition of the MEK1/2 or JNK cascades, but not of the PI3K-AKT signaling axis also induced epithelial cell morphology. Finally, we found that expression of FGF9 was strong in a subset of advanced colon cancers, and overexpression negatively correlated with patients' survival. Our functional and expression analyses suggest that FGF receptor signals can contribute to colon cancer progression. © 2011 Leushacke et al. Source