@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} }