TY  - JOUR
A1  - Herrmann, Andreas B.
A1  - Müller, Martha‐Lena
A1  - Orth, Martin F.
A1  - Müller, Jörg P.
A1  - Zernecke, Alma
A1  - Hochhaus, Andreas
A1  - Ernst, Thomas
A1  - Butt, Elke
A1  - Frietsch, Jochen J.
T1  - Knockout of LASP1 in CXCR4 expressing CML cells promotes cell persistence, proliferation and TKI resistance
JF  - Journal of Cellular and Molecular Medicine
N2  - Chronic myeloid leukaemia (CML) is a clonal myeloproliferative stem cell disorder characterized by the constitutively active BCR‐ABL tyrosine kinase. The LIM and SH3 domain protein 1 (LASP1) has recently been identified as a novel BCR‐ABL substrate and is associated with proliferation, migration, tumorigenesis and chemoresistance in several cancers. Furthermore, LASP1 was shown to bind to the chemokine receptor 4 (CXCR4), thought to be involved in mechanisms of relapse. In order to identify potential LASP1‐mediated pathways and related factors that may help to further eradicate minimal residual disease (MRD), the effect of LASP1 on processes involved in progression and maintenance of CML was investigated. The present data indicate that not only overexpression of CXCR4, but also knockout of LASP1 contributes to proliferation, reduced apoptosis and migration as well as increased adhesive potential of K562 CML cells. Furthermore, LASP1 depletion in K562 CML cells leads to decreased cytokine release and reduced NK cell‐mediated cytotoxicity towards CML cells. Taken together, these results indicate that in CML, reduced levels of LASP1 alone and in combination with high CXCR4 expression may contribute to TKI resistance.
KW  - BCR‐ABL
KW  - CML
KW  - CXCR4
KW  - LASP1
KW  - nilotinib
KW  - precursor cells
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214122
VL  - 24
IS  - 5
SP  - 2942
EP  - 2955
ER  - 
TY  - JOUR
A1  - Eisenhardt, Anja E.
A1  - Sprenger, Adrian
A1  - Röring, Michael
A1  - Herr, Ricarda
A1  - Weinberg, Florian
A1  - Köhler, Martin
A1  - Braun, Sandra
A1  - Orth, Joachim
A1  - Diedrich, Britta
A1  - Lanner, Ulrike
A1  - Tscherwinski, Natalja
A1  - Schuster, Simon
A1  - Dumaz, Nicolas
A1  - Schmidt, Enrico
A1  - Baumeister, Ralf
A1  - Schlosser, Andreas
A1  - Dengjel, Jörn
A1  - Brummer, Tilman
T1  - Phospho-proteomic analyses of B-Raf protein complexes reveal new regulatory principles
JF  - Oncotarget
N2  - B-Raf represents a critical physiological regulator of the Ras/RAF/MEK/ERK-pathway and a pharmacological target of growing clinical relevance, in particular in oncology. To understand how B-Raf itself is regulated, we combined mass spectrometry with genetic approaches to map its interactome in MCF-10A cells as well as in B-Raf deficient murine embryonic fibroblasts (MEFs) and B-Raf/Raf-1 double deficient DT40 lymphoma cells complemented with wildtype or mutant B-Raf expression vectors. Using a multi-protease digestion approach, we identified a novel ubiquitination site and provide a detailed B-Raf phospho-map. Importantly, we identify two evolutionary conserved phosphorylation clusters around T401 and S419 in the B-Raf hinge region. SILAC labelling and genetic/biochemical follow-up revealed that these clusters are phosphorylated in the contexts of oncogenic Ras, sorafenib induced Raf dimerization and in the background of the V600E mutation. We further show that the vemurafenib sensitive phosphorylation of the T401 cluster occurs in trans within a Raf dimer. Substitution of the Ser/Thr-residues of this cluster by alanine residues enhances the transforming potential of B-Raf, indicating that these phosphorylation sites suppress its signaling output. Moreover, several B-Raf phosphorylation sites, including T401 and S419, are somatically mutated in tumors, further illustrating the importance of phosphorylation for the regulation of this kinase.
KW  - BRAF
KW  - proteomics
KW  - phosphorylation
KW  - sorafenib
KW  - protein-protein interaction
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166529
VL  - 7
IS  - 18
ER  - 
TY  - JOUR
A1  - Salzmann-Manrique, Emilia
A1  - Bremm, Melanie
A1  - Huenecke, Sabine
A1  - Stech, Milena
A1  - Orth, Andreas
A1  - Eyrich, Matthias
A1  - Schulz, Ansgar
A1  - Esser, Ruth
A1  - Klingebiel, Thomas
A1  - Bader, Peter
A1  - Herrmann, Eva
A1  - Koehl, Ulrike
T1  - Joint Modeling of Immune Reconstitution Post Haploidentical Stem Cell Transplantation in Pediatric Patients With Acute Leukemia Comparing CD34(+)-Selected to CD3/CD19-Depleted Grafts in a Retrospective Multicenter Study
JF  - frontiers in Immunology
N2  - Rapid immune reconstitution (IR) following stem cell transplantation (SCT) is essential for a favorable outcome. The optimization of graft composition should not only enable a sufficient IR but also improve graft vs. leukemia/tumor effects, overcome infectious complications and, finally, improve patient survival. Especially in haploidentical SCT, the optimization of graft composition is controversial. Therefore, we analyzed the influence of graft manipulation on IR in 40 patients with acute leukemia in remission. We examined the cell recovery post haploidentical SCT in patients receiving a CD34(+)-selected or CD3/CD19-depleted graft, considering the applied conditioning regimen. We used joint model analysis for overall survival (OS) and analyzed the dynamics of age-adjusted leukocytes; lymphocytes; monocytes; CD3(+), CD3(+) CD4(+), and CD3(+) CD8(+) T cells; natural killer (NK) cells; and B cells over the course of time after SCT. Lymphocytes, NK cells, and B cells expanded more rapidly after SCT with CD34(+)-selected grafts (P = 0.036, P = 0.002, and P < 0.001, respectively). Contrarily, CD3(+) CD4(+) helper T cells recovered delayer in the CD34 selected group (P = 0.026). Furthermore, reduced intensity conditioning facilitated faster immune recovery of lymphocytes and T cells and their subsets (P < 0.001). However, the immune recovery for NK cells and B cells was comparable for patients who received reduced-intensity or full preparative regimens. Dynamics of all cell types had a significant influence on OS, which did not differ between patients receiving CD34(+)-selected and those receiving CD3/CD19-depleted grafts. In conclusion, cell reconstitution dynamics showed complex diversity with regard to the graft manufacturing procedure and conditioning regimen.
KW  - immune reconstitution
KW  - allogeneic stem cell transplantation
KW  - CD34 selection
KW  - CD3/19 depletion
KW  - children
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-227302
VL  - 9
ER  -