@article{FrietschKastnerGrunewaldetal.2014, author = {Frietsch, Jochen J. and Kastner, Carolin and Grunewald, Thomas G.P. and Schweigel, Hardy and Nollau, Peter and Ziermann, Janine and Clement, Joachim H. and La Res{\´e}e, Paul and Hochhaus, Andreas and Butt, Elke}, title = {LASP1 is a novel BCR-ABL substrate and a phosphorylation-dependent binding partner of CRKL in chronic myeloid leukemia}, series = {Oncotarget}, volume = {5}, journal = {Oncotarget}, number = {14}, issn = {1949-2553}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120639}, pages = {5257-71}, year = {2014}, abstract = {Chronic myeloid leukemia (CML) is characterized by a genomic translocation generating a permanently active BCR-ABL oncogene with a complex pattern of atypically tyrosine-phosphorylated proteins that drive the malignant phenotype of CML. Recently, the LIM and SH3 domain protein 1 (LASP1) was identified as a component of a six gene signature that is strongly predictive for disease progression and relapse in CML patients. However, the underlying mechanisms why LASP1 expression correlates with dismal outcome remained unresolved. Here, we identified LASP1 as a novel and overexpressed direct substrate of BCR-ABL in CML. We demonstrate that LASP1 is specifically phosphorylated by BCR-ABL at tyrosine-171 in CML patients, which is abolished by tyrosine kinase inhibitor therapy. Further studies revealed that LASP1 phosphorylation results in an association with CRKL - another specific BCR-ABL substrate and bona fide biomarker for BCR-ABL activity. pLASP1-Y171 binds to non-phosphorylated CRKL at its SH2 domain. Accordingly, the BCR-ABL-mediated pathophysiological hyper-phosphorylation of LASP1 in CML disrupts normal regulation of CRKL and LASP1, which likely has implications on downstream BCR-ABL signaling. Collectively, our results suggest that LASP1 phosphorylation might serve as an additional candidate biomarker for assessment of BCR-ABL activity and provide a first step toward a molecular understanding of LASP1 function in CML.}, language = {en} } @article{GratwohlPfirrmannZanderetal.2016, author = {Gratwohl, A and Pfirrmann, M and Zander, A and Kr{\"o}ger, N and Beelen, D and Novotny, J and Nerl, C and Scheid, C and Spiekermann, K and Mayer, J and Sayer, HG and Falge, C and Bunjes, D and D{\"o}hner, H and Ganser, A and Schmidt-Wolf, I and Schwerdtfeger, R and Baurmann, H and Kuse, R and Schmitz, N and Wehmeier, A and Fischer, J Th and Ho, AD and Wilhelm, M and Goebeler, M-E and Lindemann, HW and Bormann, M and Hertenstein, B and Schlimok, G and Baerlocher, GM and Aul, C and Pfreundschuh, M and Fabian, M and Staib, P and Edinger, M and Schatz, M and Fauser, A and Arnold, R and Kindler, T and Wulf, G and Rosselet, A and Hellmann, A and Sch{\"a}fer, E and Pr{\"u}mmer, O and Schenk, M and Hasford, J and Heimpel, H and Hossfeld, DK and Kolb, H-J and B{\"u}sche, G and Haferlach, C and Schnittger, S and M{\"u}ller, MC and Reiter, A and Berger, U and Saußele, S and Hochhaus, A and Hehlmann, R}, title = {Long-term outcome of patients with newly diagnosed chronic myeloid leukemia: a randomized comparison of stem cell transplantation with drug treatment}, series = {Leukemia}, volume = {30}, journal = {Leukemia}, doi = {10.1038/leu.2015.281}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-150368}, pages = {562-569}, year = {2016}, abstract = {Tyrosine kinase inhibitors represent today's treatment of choice in chronic myeloid leukemia (CML). Allogeneic hematopoietic stem cell transplantation (HSCT) is regarded as salvage therapy. This prospective randomized CML-study IIIA recruited 669 patients with newly diagnosed CML between July 1997 and January 2004 from 143 centers. Of these, 427 patients were considered eligible for HSCT and were randomized by availability of a matched family donor between primary HSCT (group A; N=166 patients) and best available drug treatment (group B; N=261). Primary end point was long-term survival. Survival probabilities were not different between groups A and B (10-year survival: 0.76 (95\% confidence interval (CI): 0.69-0.82) vs 0.69 (95\% CI: 0.61-0.76)), but influenced by disease and transplant risk. Patients with a low transplant risk showed superior survival compared with patients with high- (P<0.001) and non-high-risk disease (P=0.047) in group B; after entering blast crisis, survival was not different with or without HSCT. Significantly more patients in group A were in molecular remission (56\% vs 39\%; P = 0.005) and free of drug treatment (56\% vs 6\%; P<0.001). Differences in symptoms and Karnofsky score were not significant. In the era of tyrosine kinase inhibitors, HSCT remains a valid option when both disease and transplant risk are considered.}, language = {en} } @article{RinaldettiPfirrmannManzetal.2018, author = {Rinaldetti, S{\´e}bastien and Pfirrmann, Markus and Manz, Kirsi and Guilhot, Joelle and Dietz, Christian and Panagiotidis, Panayiotidis and Spiess, Birgit and Seifarth, Wolfgang and Fabarius, Alice and M{\"u}ller, Martin and Pagoni, Maria and Dimou, Maria and Dengler, Jolanta and Waller, Cornelius F. and Br{\"u}mmendorf, Tim H. and Herbst, Regina and Burchert, Andreas and Janßen, Carsten and Goebeler, Maria Elisabeth and Jost, Philipp J. and Hanzel, Stefan and Schafhausen, Philippe and Prange-Krex, Gabriele and Illmer, Thomas and Janzen, Viktor and Klausmann, Martine and Eckert, Robert and B{\"u}schel, Gerd and Kiani, Alexander and Hofmann, Wolf-Karsten and Mahon, Fran{\c{c}}ois-Xavier and Saussele, Susanne}, title = {Effect of ABCG2, OCT1, and ABCB1 (MDR1) Gene Expression on Treatment-Free Remission in a EURO-SKI Subtrial}, series = {Clinical Lymphoma, Myeloma \& Leukemia}, volume = {18}, journal = {Clinical Lymphoma, Myeloma \& Leukemia}, number = {4}, doi = {10.1016/j.clml.2018.02.004}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226281}, pages = {266-271}, year = {2018}, abstract = {Within the EURO-SKI trial, 132 chronic phase CML patients discontinued imatinib treatment. RNA was isolated from peripheral blood in order to analyze the expression of MDR1, ABCG2 and OCT1. ABCG2 was predictive for treatment-free remission in Cox regression analysis. High transcript levels of the ABCG2 efflux transporter (>4.5 parts per thousand) were associated with a twofold higher risk of relapse. Introduction: Tyrosine kinase inhibitors (TKIs) can safely be discontinued in chronic myeloid leukemia (CML) patients with sustained deep molecular response. ABCG2 (breast cancer resistance protein), OCT1 (organic cation transporter 1), and ABCB1 (multidrug resistance protein 1) gene products are known to play a crucial role in acquired pharmacogenetic TKI resistance. Their influence on treatment-free remission (TFR) has not yet been investigated. Materials and Methods: RNA was isolated on the last day of TKI intake from peripheral blood leukocytes of 132 chronic phase CML patients who discontinued TKI treatment within the European Stop Tyrosine Kinase Inhibitor Study trial. Plasmid standards were designed including subgenic inserts of OCT1, ABCG2, and ABCB1 together with GUSB as reference gene. For expression analyses, quantitative real-time polymerase chain reaction was used. Multiple Cox regression analysis was performed. In addition, gene expression cutoffs for patient risk stratification were investigated. Results: The TFR rate of 132 patients, 12 months after TKI discontinuation, was 54\% (95\% confidence interval [CI], 46\%-62\%). ABCG2 expression (parts per thousand) was retained as the only significant variable (P=.02; hazard ratio, 1.04; 95\% CI, 1.01-1.07) in multiple Cox regression analysis. Only for the ABCG2 efflux transporter, a significant cutoff was found (P=.04). Patients with an ABCG2/GUSB transcript level >4.5 parts per thousand (n=93) showed a 12-month TFR rate of 47\% (95\% CI, 37\%-57\%), whereas patients with low ABCG2 expression (<= 4.5 parts per thousand; n=39) had a 12-month TFR rate of 72\% (95\% CI, 55\%-82\%). Conclusion: In this study, we investigated the effect of pharmacogenetics in the context of a CML treatment discontinuation trial. The transcript levels of the efflux transporter ABCG2 predicted TFR after TKI discontinuation. (C) 2018 The Authors. Published by Elsevier Inc.}, language = {en} } @article{HerrmannMuellerOrthetal.2020, author = {Herrmann, Andreas B. and M{\"u}ller, Martha-Lena and Orth, Martin F. and M{\"u}ller, J{\"o}rg P. and Zernecke, Alma and Hochhaus, Andreas and Ernst, Thomas and Butt, Elke and Frietsch, Jochen J.}, title = {Knockout of LASP1 in CXCR4 expressing CML cells promotes cell persistence, proliferation and TKI resistance}, series = {Journal of Cellular and Molecular Medicine}, volume = {24}, journal = {Journal of Cellular and Molecular Medicine}, number = {5}, doi = {10.1111/jcmm.14910}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-214122}, pages = {2942 -- 2955}, year = {2020}, abstract = {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.}, language = {en} } @article{ButtStempfleListeretal.2020, author = {Butt, Elke and Stempfle, Katrin and Lister, Lorenz and Wolf, Felix and Kraft, Marcella and Herrmann, Andreas B. and Viciano, Cristina Perpina and Weber, Christian and Hochhaus, Andreas and Ernst, Thomas and Hoffmann, Carsten and Zernecke, Alma and Frietsch, Jochen J.}, title = {Phosphorylation-dependent differences in CXCR4-LASP1-AKT1 interaction between breast cancer and chronic myeloid leukemia}, series = {Cells}, volume = {9}, journal = {Cells}, number = {2}, issn = {2073-4409}, doi = {10.3390/cells9020444}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200638}, year = {2020}, abstract = {The serine/threonine protein kinase AKT1 is a downstream target of the chemokine receptor 4 (CXCR4), and both proteins play a central role in the modulation of diverse cellular processes, including proliferation and cell survival. While in chronic myeloid leukemia (CML) the CXCR4 is downregulated, thereby promoting the mobilization of progenitor cells into blood, the receptor is highly expressed in breast cancer cells, favoring the migratory capacity of these cells. Recently, the LIM and SH3 domain protein 1 (LASP1) has been described as a novel CXCR4 binding partner and as a promoter of the PI3K/AKT pathway. In this study, we uncovered a direct binding of LASP1, phosphorylated at S146, to both CXCR4 and AKT1, as shown by immunoprecipitation assays, pull-down experiments, and immunohistochemistry data. In contrast, phosphorylation of LASP1 at Y171 abrogated these interactions, suggesting that both LASP1 phospho-forms interact. Finally, findings demonstrating different phosphorylation patterns of LASP1 in breast cancer and chronic myeloid leukemia may have implications for CXCR4 function and tyrosine kinase inhibitor treatment.}, language = {en} }