@article{GaritanoTrojaolaSanchoGoetzetal.2021, author = {Garitano-Trojaola, Andoni and Sancho, Ana and G{\"o}tz, Ralph and Eiring, Patrick and Walz, Susanne and Jetani, Hardikkumar and Gil-Pulido, Jesus and Da Via, Matteo Claudio and Teufel, Eva and Rhodes, Nadine and Haertle, Larissa and Arellano-Viera, Estibaliz and Tibes, Raoul and Rosenwald, Andreas and Rasche, Leo and Hudecek, Michael and Sauer, Markus and Groll, J{\"u}rgen and Einsele, Hermann and Kraus, Sabrina and Kort{\"u}m, Martin K.}, title = {Actin cytoskeleton deregulation confers midostaurin resistance in FLT3-mutant acute myeloid leukemia}, series = {Communications Biology}, volume = {4}, journal = {Communications Biology}, number = {1}, doi = {10.1038/s42003-021-02215-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260709}, year = {2021}, abstract = {The presence of FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) is one of the most frequent mutations in acute myeloid leukemia (AML) and is associated with an unfavorable prognosis. FLT3 inhibitors, such as midostaurin, are used clinically but fail to entirely eradicate FLT3-ITD+AML. This study introduces a new perspective and highlights the impact of RAC1-dependent actin cytoskeleton remodeling on resistance to midostaurin in AML. RAC1 hyperactivation leads resistance via hyperphosphorylation of the positive regulator of actin polymerization N-WASP and antiapoptotic BCL-2. RAC1/N-WASP, through ARP2/3 complex activation, increases the number of actin filaments, cell stiffness and adhesion forces to mesenchymal stromal cells (MSCs) being identified as a biomarker of resistance. Midostaurin resistance can be overcome by a combination of midostaruin, the BCL-2 inhibitor venetoclax and the RAC1 inhibitor Eht1864 in midostaurin-resistant AML cell lines and primary samples, providing the first evidence of a potential new treatment approach to eradicate FLT3-ITD+AML. Garitano-Trojaola et al. used a combination of human acute myeloid leukemia (AML) cell lines and primary samples to show that RAC1-dependent actin cytoskeleton remodeling through BCL2 family plays a key role in resistance to the FLT3 inhibitor, Midostaurin in AML. They showed that by targeting RAC1 and BCL2, Midostaurin resistance was diminished, which potentially paves the way for an innovate treatment approach for FLT3 mutant AML.}, language = {en} } @article{BaeuerleinQureischiMokhtarietal.2021, author = {B{\"a}uerlein, Carina A. and Qureischi, Musga and Mokhtari, Zeinab and Tabares, Paula and Brede, Christian and Jord{\´a}n Garrote, Ana-Laura and Riedel, Simone S. and Chopra, Martin and Reu, Simone and Mottok, Anja and Arellano-Viera, Estibaliz and Graf, Carolin and Kurzwart, Miriam and Schmiedgen, Katharina and Einsele, Hermann and W{\"o}lfl, Matthias and Schlegel, Paul-Gerhardt and Beilhack, Andreas}, title = {A T-Cell Surface Marker Panel Predicts Murine Acute Graft-Versus-Host Disease}, series = {Frontiers in Immunology}, volume = {11}, journal = {Frontiers in Immunology}, issn = {1664-3224}, doi = {10.3389/fimmu.2020.593321}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224290}, year = {2021}, abstract = {Acute graft-versus-host disease (aGvHD) is a severe and often life-threatening complication of allogeneic hematopoietic cell transplantation (allo-HCT). AGvHD is mediated by alloreactive donor T-cells targeting predominantly the gastrointestinal tract, liver, and skin. Recent work in mice and patients undergoing allo-HCT showed that alloreactive T-cells can be identified by the expression of α4β7 integrin on T-cells even before manifestation of an aGvHD. Here, we investigated whether the detection of a combination of the expression of T-cell surface markers on peripheral blood (PB) CD8\(^+\) T-cells would improve the ability to predict aGvHD. To this end, we employed two independent preclinical models of minor histocompatibility antigen mismatched allo-HCT following myeloablative conditioning. Expression profiles of integrins, selectins, chemokine receptors, and activation markers of PB donor T-cells were measured with multiparameter flow cytometry at multiple time points before the onset of clinical aGvHD symptoms. In both allo-HCT models, we demonstrated a significant upregulation of α4β7 integrin, CD162E, CD162P, and conversely, a downregulation of CD62L on donor T-cells, which could be correlated with the development of aGvHD. Other surface markers, such as CD25, CD69, and CC-chemokine receptors were not found to be predictive markers. Based on these preclinical data from mouse models, we propose a surface marker panel on peripheral blood T-cells after allo-HCT combining α4β7 integrin with CD62L, CD162E, and CD162P (cutaneous lymphocyte antigens, CLA, in humans) to identify patients at risk for developing aGvHD early after allo-HCT.}, language = {en} }