TY  - JOUR
A1  - Garitano-Trojaola, Andoni
A1  - Sancho, Ana
A1  - Götz, Ralph
A1  - Eiring, Patrick
A1  - Walz, Susanne
A1  - Jetani, Hardikkumar
A1  - Gil-Pulido, Jesus
A1  - Da Via, Matteo Claudio
A1  - Teufel, Eva
A1  - Rhodes, Nadine
A1  - Haertle, Larissa
A1  - Arellano-Viera, Estibaliz
A1  - Tibes, Raoul
A1  - Rosenwald, Andreas
A1  - Rasche, Leo
A1  - Hudecek, Michael
A1  - Sauer, Markus
A1  - Groll, Jürgen
A1  - Einsele, Hermann
A1  - Kraus, Sabrina
A1  - Kortüm, Martin K.
T1  - Actin cytoskeleton deregulation confers midostaurin resistance in FLT3-mutant acute myeloid leukemia
JF  - Communications Biology
N2  - 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.
KW  - actin
KW  - acute myeloid leukaemia
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260709
VL  - 4
IS  - 1
ER  - 
TY  - JOUR
A1  - Zhou, Xiang
A1  - Steinhardt, Maximilian Johannes
A1  - Düll, Johannes
A1  - Krummenast, Franziska
A1  - Danhof, Sophia
A1  - Meckel, Katharina
A1  - Nickel, Katharina
A1  - Grathwohl, Denise
A1  - Leicht, Hans‐Benno
A1  - Rosenwald, Andreas
A1  - Einsele, Hermann
A1  - Rasche, Leo
A1  - Kortüm, Martin
T1  - Obinutuzumab and venetoclax induced complete remission in a patient with ibrutinib‐resistant non‐nodal leukemic mantle cell lymphoma
JF  - European Journal of Haematology
N2  - We herein report the case of a 73‐year‐old male patient who was diagnosed with leukemic non‐nodal MCL. This patient had received six cycles of bendamustine, which resulted in a transient remission, and a second‐line therapy with ibrutinib, which unfortunately failed to induce remission. We started a treatment with single‐agent obinutuzumab at a dose of 20 mg on day 1, 50 mg on day 2‐4, 330 mg on day 5, and 1000 mg on day 6. The laboratory analysis showed a rapid decrease of leukocyte count. Four weeks later, we repeated the treatment with obinutuzumab at a dose of 1000 mg q4w and started a therapy with venetoclax at a dose of 400 mg qd, which could be increased to 800 mg qd from the third cycle. This combination therapy was well tolerated. The patient achieved a complete remission (CR) after three cycles of obinutuzumab and venetoclax. To date, the patient has a progression‐free survival of 17 months under ongoing obinutuzumab maintenance q4w. This is the first report about obinutuzumab and venetoclax induced CR in rituximab‐intolerant patient with an ibrutinib‐resistant MCL. This case suggests that obinutuzumab‐ and venetoclax‐based combination therapy might be salvage therapy in patients with ibrutinib‐resistant MCL.
KW  - mantle cell lymphoma
KW  - obinutuzumab
KW  - venetoclax
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-215513
VL  - 104
IS  - 4
SP  - 352
EP  - 355
ER  -