@article{SchwinnMokhtariThuseketal.2021, author = {Schwinn, Stefanie and Mokhtari, Zeinab and Thusek, Sina and Schneider, Theresa and Sir{\´e}n, Anna-Leena and Tiemeyer, Nicola and Caruana, Ignazio and Miele, Evelina and Schlegel, Paul G. and Beilhack, Andreas and W{\"o}lfl, Matthias}, title = {Cytotoxic effects and tolerability of gemcitabine and axitinib in a xenograft model for c-myc amplified medulloblastoma}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-021-93586-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-261476}, year = {2021}, abstract = {Medulloblastoma is the most common high-grade brain tumor in childhood. Medulloblastomas with c-myc amplification, classified as group 3, are the most aggressive among the four disease subtypes resulting in a 5-year overall survival of just above 50\%. Despite current intensive therapy regimens, patients suffering from group 3 medulloblastoma urgently require new therapeutic options. Using a recently established c-myc amplified human medulloblastoma cell line, we performed an in-vitro-drug screen with single and combinatorial drugs that are either already clinically approved or agents in the advanced stage of clinical development. Candidate drugs were identified in vitro and then evaluated in vivo. Tumor growth was closely monitored by BLI. Vessel development was assessed by 3D light-sheet-fluorescence-microscopy. We identified the combination of gemcitabine and axitinib to be highly cytotoxic, requiring only low picomolar concentrations when used in combination. In the orthotopic model, gemcitabine and axitinib showed efficacy in terms of tumor control and survival. In both models, gemcitabine and axitinib were better tolerated than the standard regimen comprising of cisplatin and etoposide phosphate. 3D light-sheet-fluorescence-microscopy of intact tumors revealed thinning and rarefication of tumor vessels, providing one explanation for reduced tumor growth. Thus, the combination of the two drugs gemcitabine and axitinib has favorable effects on preventing tumor progression in an orthotopic group 3 medulloblastoma xenograft model while exhibiting a favorable toxicity profile. The combination merits further exploration as a new approach to treat high-risk group 3 medulloblastoma.}, language = {en} } @article{DahlhoffManzSteinfattetal.2022, author = {Dahlhoff, Julia and Manz, Hannah and Steinfatt, Tim and Delgado-Tascon, Julia and Seebacher, Elena and Schneider, Theresa and Wilnit, Amy and Mokhtari, Zeinab and Tabares, Paula and B{\"o}ckle, David and Rasche, Leo and Martin Kort{\"u}m, K. and Lutz, Manfred B. and Einsele, Hermann and Brandl, Andreas and Beilhack, Andreas}, title = {Transient regulatory T-cell targeting triggers immune control of multiple myeloma and prevents disease progression}, series = {Leukemia}, volume = {36}, journal = {Leukemia}, number = {3}, issn = {1476-5551}, doi = {10.1038/s41375-021-01422-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-271787}, pages = {790-800}, year = {2022}, abstract = {Multiple myeloma remains a largely incurable disease of clonally expanding malignant plasma cells. The bone marrow microenvironment harbors treatment-resistant myeloma cells, which eventually lead to disease relapse in patients. In the bone marrow, CD4\(^{+}\)FoxP3\(^{+}\) regulatory T cells (Tregs) are highly abundant amongst CD4\(^{+}\) T cells providing an immune protective niche for different long-living cell populations, e.g., hematopoietic stem cells. Here, we addressed the functional role of Tregs in multiple myeloma dissemination to bone marrow compartments and disease progression. To investigate the immune regulation of multiple myeloma, we utilized syngeneic immunocompetent murine multiple myeloma models in two different genetic backgrounds. Analyzing the spatial immune architecture of multiple myeloma revealed that the bone marrow Tregs accumulated in the vicinity of malignant plasma cells and displayed an activated phenotype. In vivo Treg depletion prevented multiple myeloma dissemination in both models. Importantly, short-term in vivo depletion of Tregs in mice with established multiple myeloma evoked a potent CD8 T cell- and NK cell-mediated immune response resulting in complete and stable remission. Conclusively, this preclinical in-vivo study suggests that Tregs are an attractive target for the treatment of multiple myeloma.}, language = {en} }