Articles by Dominik Schnerch in JoVE
Studying Proteolysis of Cyclin B at the Single Cell Level in Whole Cell Populations Dominik Schnerch1, Marie Follo1, Julia Felthaus1, Monika Engelhardt1, Ralph Wäsch1 1Department of Hematology, Oncology and Stem Cell Transplantation, University Medical Center Freiburg Metaphase to anaphase transition is triggered through anaphase-promoting complex (APC/C)-dependent ubiquitination and subsequent destruction of cyclin B. Here, we established a system which, following pulse-chase labeling, allows monitoring cyclin B proteolysis in entire cell populations and facilitates the detection of interference by the mitotic checkpoint.
Other articles by Dominik Schnerch on PubMed
Management of Multiple Myeloma in Pregnancy: Strategies for a Rare Challenge Clinical Lymphoma, Myeloma & Leukemia. Apr, 2011 | Pubmed ID: 21575923 Multiple myeloma is the second most commonly diagnosed hematologic malignancy. It is characterized by the accumulation of monoclonal plasma cells. It typically manifests in the sixth decade of life or later, whereas the incidence in patients who are younger than 40 years old is extremely rare. Here, we report the case of a 34-year-old prima gravida, diagnosed with a Îº light-chain myeloma (Durie&Salmon stage IIIA, International Staging System I) in the 23rd week of pregnancy. Our multimodal therapeutic approach during pregnancy, the delivery of a healthy male, and initiation of intensive anti-myeloma treatment thereafter (induction with bortezomib, cyclophosphamide, and dexamethasone, followed by tandem autologous peripheral blood stem cell transplantation) are described. Furthermore, we provide a comprehensive review of all 18 cases published between 1965 and 2010 in which a multiple myeloma was diagnosed and treated following different regimes and approaches before, during, or shortly after pregnancy. All delivered newborns were healthy, whereas the mothers' outcomes varied strongly. In our specific case, complete remission was achieved after tandem autologous peripheral blood stem cell transplantation. Emerging from these literature data and our case, we conclude that while awaiting delivery, the application of prednisolone as a nontoxic, but active anti-myeloma therapy can be recommended. Intensified postpartum anti-myeloma therapy should be induced as soon as possible to efficiently reduce myeloma burden and avoid organ damage in these young females.
Monitoring APC/C Activity in the Presence of Chromosomal Misalignment in Unperturbed Cell Populations Cell Cycle (Georgetown, Tex.). Jan, 2012 | Pubmed ID: 22214763 Chromosome segregation is under strict control of the spindle assembly checkpoint (SAC). The SAC regulates anaphase-promoting complex/cyclosome (APC/C)-dependent proteolysis of securin and cyclin B. Unattached or misaligned chromosomes trigger SAC-mediated mitotic delay by stabilizing securin and cyclin B due to inhibition of APC/C until the problem is solved. Here we present a hitherto unavailable model facilitating the simultaneous depiction of chromosome movements and pulse-chased cyclin B proteolysis in every single cell within a cell population. During chromosome misalignment, we observed slow cyclin B degradation, which changed to fast degradation once the SAC was satisfied, initiating chromosome separation and mitotic exit. Slow degradation during a SAC-mediated mitotic delay is part of a tightly regulated balance between cyclin B synthesis and degradation. Since chromosomal misalignment is a rare event, the ability to study entire cell populations enabled us to monitor for the first time SAC surveillance in living cells without the need of highly artificial perturbation by spindle poisons.
Cell Cycle Control in Acute Myeloid Leukemia American Journal of Cancer Research. 2012 | Pubmed ID: 22957304 Acute myeloid leukemia (AML) is the result of a multistep transforming process of hematopoietic precursor cells (HPCs) which enables them to proceed through limitless numbers of cell cycles and to become resistant to cell death. Increased proliferation renders these cells vulnerable to acquiring mutations and may favor leukemic transformation. Here, we review how deregulated cell cycle control contributes to increased proliferation in AML and favors genomic instability, a prerequisite to confer selective advantages to particular clones in order to adapt and independently proliferate in the presence of a changing microenvironment. We discuss the connection between differentiation and proliferation with regard to leukemogenesis and outline the impact of specific alterations on response to therapy. Finally, we present examples, how a better understanding of cell cycle regulation and deregulation has already led to new promising therapeutic strategies.