@article{SteinhardtKrummenastRosenwaldetal.2022, author = {Steinhardt, Maximilian J. and Krummenast, Franziska C. and Rosenwald, Andreas and Gerhard-Hartmann, Elena and Heidemeier, Anke and Einsele, Hermann and Topp, Max S. and Duell, Johannes}, title = {R-CHOP intensification with mid-cycle methotrexate and consolidating AraC/TT with BCNU/aHSCT in primary aggressive lymphoma with CNS involvement}, series = {Journal of Cancer Research and Clinical Oncology}, volume = {148}, journal = {Journal of Cancer Research and Clinical Oncology}, number = {1}, issn = {1432-1335}, doi = {10.1007/s00432-021-03663-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267731}, pages = {205-214}, year = {2022}, abstract = {Purpose Patients suffering from aggressive systemic peripheral lymphoma with primary central nervous system involvement (PCL) are a rare and sparsely investigated population. Recommended treatment regimens include a combination of intrathecal and systemic chemotherapy as well as whole brain radiotherapy while offering relatively poor survival. Methods We conducted a single-center retrospective study that analyzed safety and outcome of 4 + 4 cycles Rituximab (R)-CHOP and R-high-dose Methotrexate (HD-MTX) for newly diagnosed, transplant-eligible patients ("Ping-Pong"), followed by Cytarabine (AraC)/Thiotepa (TT), BCNU/TT, and autologous hematologic stem cell transplantation (aHSCT). We retrospectively analyzed a set of 16 patients with high-intermediate or high-risk IPI status. Results Overall response rate to Ping-Pong was 100\% measured by CT/MRI, including 93.75\% complete remissions after BCNU/TT followed by PBSCT. One patient failed to qualify for high-dose chemotherapy due to progression when receiving Cytarabine/TT. All patients experienced grade III adverse events, 3 of them a grade IV adverse event. Estimated progression-free survival is 93.75\% after a 4.8-year follow-up currently. Conclusion Our study suggests high effectivity of R-CHOP with mid-cycle MTX with aHSCT consolidation towards acceptable OS results in this challenging patient population.}, language = {en} } @article{DetomasAltieriSchloetelburgetal.2021, author = {Detomas, Mario and Altieri, Barbara and Schl{\"o}telburg, Wiebke and Appenzeller, Silke and Schlaffer, Sven and Coras, Roland and Schirbel, Andreas and Wild, Vanessa and Kroiss, Matthias and Sbiera, Silviu and Fassnacht, Martin and Deutschbein, Timo}, title = {Case Report: Consecutive Adrenal Cushing's Syndrome and Cushing's Disease in a Patient With Somatic CTNNB1, USP8, and NR3C1 Mutations}, series = {Frontiers in Endocrinology}, volume = {12}, journal = {Frontiers in Endocrinology}, issn = {1664-2392}, doi = {10.3389/fendo.2021.731579}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244596}, year = {2021}, abstract = {The occurrence of different subtypes of endogenous Cushing's syndrome (CS) in single individuals is extremely rare. We here present the case of a female patient who was successfully cured from adrenal CS 4 years before being diagnosed with Cushing's disease (CD). The patient was diagnosed at the age of 50 with ACTH-independent CS and a left-sided adrenal adenoma, in January 2015. After adrenalectomy and histopathological confirmation of a cortisol-producing adrenocortical adenoma, biochemical hypercortisolism and clinical symptoms significantly improved. However, starting from 2018, the patient again developed signs and symptoms of recurrent CS. Subsequent biochemical and radiological workup suggested the presence of ACTH-dependent CS along with a pituitary microadenoma. The patient underwent successful transsphenoidal adenomectomy, and both postoperative adrenal insufficiency and histopathological workup confirmed the diagnosis of CD. Exome sequencing excluded a causative germline mutation but showed somatic mutations of the β-catenin protein gene (CTNNB1) in the adrenal adenoma, and of both the ubiquitin specific peptidase 8 (USP8) and the glucocorticoid receptor (NR3C1) genes in the pituitary adenoma. In conclusion, our case illustrates that both ACTH-independent and ACTH-dependent CS may develop in a single individual even without evidence for a common genetic background.}, language = {en} } @article{ChifuHeinzeFussetal.2020, author = {Chifu, Irina and Heinze, Britta and Fuss, Carmina T. and Lang, Katharina and Kroiss, Matthias and Kircher, Stefan and Ronchi, Cristina L. and Altieri, Barbara and Schirbel, Andreas and Fassnacht, Martin and Hahner, Stefanie}, title = {Impact of the Chemokine Receptors CXCR4 and CXCR7 on Clinical Outcome in Adrenocortical Carcinoma}, series = {Frontiers in Endocrinology}, volume = {11}, journal = {Frontiers in Endocrinology}, issn = {1664-2392}, doi = {10.3389/fendo.2020.597878}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-216494}, year = {2020}, abstract = {Chemokine receptors have a negative impact on tumor progression in several human cancers and have therefore been of interest for molecular imaging and targeted therapy. However, their clinical and prognostic significance in adrenocortical carcinoma (ACC) is unknown. The aim of this study was to evaluate the chemokine receptor profile in ACC and to analyse its association with clinicopathological characteristics and clinical outcome. A chemokine receptor profile was initially evaluated by quantitative PCR in 4 normal adrenals, 18 ACC samples and human ACC cell line NCI-H295. High expression of CXCR4 and CXCR7 in both healthy and malignant adrenal tissue and ACC cells was confirmed. In the next step, we analyzed the expression and cellular localization of CXCR4 and CXCR7 in ACC by immunohistochemistry in 187 and 84 samples, respectively. These results were correlated with clinicopathological parameters and survival outcome. We detected strong membrane expression of CXCR4 and CXCR7 in 50\% of ACC samples. Strong cytoplasmic CXCR4 staining was more frequent among samples derived from metastases compared to primaries (p=0.01) and local recurrences (p=0.04). CXCR4 membrane staining positively correlated with proliferation index Ki67 (r=0.17, p=0.028). CXCR7 membrane staining negatively correlated with Ki67 (r=-0.254, p=0.03) but positively with tumor size (r=0.3, p=0.02). No differences in progression-free or overall survival were observed between patients with strong and weak staining intensities for CXCR4 or CXCR7. Taken together, high expression of CXCR4 and CXCR7 in both local tumors and metastases suggests that some ACC patients might benefit from CXCR4/CXCR7-targeted therapy.}, language = {en} } @article{MarquardtKollmannsbergerKrebsetal.2022, author = {Marquardt, Andr{\´e} and Kollmannsberger, Philip and Krebs, Markus and Argentiero, Antonella and Knott, Markus and Solimando, Antonio Giovanni and Kerscher, Alexander Georg}, title = {Visual clustering of transcriptomic data from primary and metastatic tumors — dependencies and novel pitfalls}, series = {Genes}, volume = {13}, journal = {Genes}, number = {8}, issn = {2073-4425}, doi = {10.3390/genes13081335}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-281872}, year = {2022}, abstract = {Personalized oncology is a rapidly evolving area and offers cancer patients therapy options that are more specific than ever. However, there is still a lack of understanding regarding transcriptomic similarities or differences of metastases and corresponding primary sites. Applying two unsupervised dimension reduction methods (t-Distributed Stochastic Neighbor Embedding (t-SNE) and Uniform Manifold Approximation and Projection (UMAP)) on three datasets of metastases (n = 682 samples) with three different data transformations (unprocessed, log10 as well as log10 + 1 transformed values), we visualized potential underlying clusters. Additionally, we analyzed two datasets (n = 616 samples) containing metastases and primary tumors of one entity, to point out potential familiarities. Using these methods, no tight link between the site of resection and cluster formation outcome could be demonstrated, or for datasets consisting of solely metastasis or mixed datasets. Instead, dimension reduction methods and data transformation significantly impacted visual clustering results. Our findings strongly suggest data transformation to be considered as another key element in the interpretation of visual clustering approaches along with initialization and different parameters. Furthermore, the results highlight the need for a more thorough examination of parameters used in the analysis of clusters.}, language = {en} } @article{StaussBrunnerBerberichSiebeltetal.2016, author = {Stauss, Dennis and Brunner, Cornelia and Berberich-Siebelt, Friederike and H{\"o}pken, Uta E. and Lipp, Martin and M{\"u}ller, Gerd}, title = {The transcriptional coactivator Bob1 promotes the development of follicular T helper cells via Bcl6}, series = {Embo Journal}, volume = {35}, journal = {Embo Journal}, number = {8}, doi = {10.15252/embj.201591459}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-189506}, pages = {881-898}, year = {2016}, abstract = {Follicular T helper (Tfh) cells are key regulators of the germinal center reaction and long-term humoral immunity. Tfh cell differentiation requires the sustained expression of the transcriptional repressor Bcl6; however, its regulation in CD4\(^+\) T cells is incompletely understood. Here, we report that the transcriptional coactivator Bob1, encoded by the Pou2af1 gene, promotes Bcl6 expression and Tfh cell development. We found that Bob1 together with the octamer transcription factors Oct1/Oct2 can directly bind to and transactivate the Bcl6 and Btla promoters. Mixed bone marrow chimeras revealed that Bob1 is required for the expression of normal levels of Bcl6 and BTLA, thereby controlling the pool size and composition of the Tfh compartment in a T cell-intrinsic manner. Our data indicate that T cell-expressed Bob1 is directly involved in Tfh cell differentiation and required for mounting normal T cell-dependent B-cell responses.}, language = {en} } @article{KressJessenMarquardtetal.2021, author = {Kreß, Julia Katharina Charlotte and Jessen, Christina and Marquardt, Andr{\´e} and Hufnagel, Anita and Meierjohann, Svenja}, title = {NRF2 enables EGFR signaling in melanoma cells}, series = {International Journal of Molecular Sciences}, volume = {22}, journal = {International Journal of Molecular Sciences}, number = {8}, issn = {1422-0067}, doi = {10.3390/ijms22083803}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260222}, year = {2021}, abstract = {Receptor tyrosine kinases (RTK) are rarely mutated in cutaneous melanoma, but the expression and activation of several RTK family members are associated with a proinvasive phenotype and therapy resistance. Epidermal growth factor receptor (EGFR) is a member of the RTK family and is only expressed in a subgroup of melanomas with poor prognosis. The insight into regulators of EGFR expression and activation is important for the understanding of the development of this malignant melanoma phenotype. Here, we describe that the transcription factor NRF2, the master regulator of the oxidative and electrophilic stress response, mediates the expression and activation of EGFR in melanoma by elevating the levels of EGFR as well as its ligands EGF and TGFα. ChIP sequencing data show that NRF2 directly binds to the promoter of EGF, which contains a canonical antioxidant response element. Accordingly, EGF is induced by oxidative stress and is also increased in lung adenocarcinoma and head and neck carcinoma with mutationally activated NRF2. In contrast, regulation of EGFR and TGFA occurs by an indirect mechanism, which is enabled by the ability of NRF2 to block the activity of the melanocytic lineage factor MITF in melanoma. MITF effectively suppresses EGFR and TGFA expression and therefore serves as link between NRF2 and EGFR. As EGFR was previously described to stimulate NRF2 activity, the mutual activation of NRF2 and EGFR pathways was investigated. The presence of NRF2 was necessary for full EGFR pathway activation, as NRF2-knockout cells showed reduced AKT activation in response to EGF stimulation compared to controls. Conversely, EGF led to the nuclear localization and activation of NRF2, thereby demonstrating that NRF2 and EGFR are connected in a positive feedback loop in melanoma. In summary, our data show that the EGFR-positive melanoma phenotype is strongly supported by NRF2, thus revealing a novel maintenance mechanism for this clinically challenging melanoma subpopulation.}, language = {en} } @article{GroebnerWorstWeischenfeldtetal.2018, author = {Gr{\"o}bner, Susanne N. and Worst, Barbara C. and Weischenfeldt, Joachim and Buchhalter, Ivo and Kleinheinz, Kortine and Rudneva, Vasilisa A. and Johann, Pascal D. and Balasubramanian, Gnana Prakash and Segura-Wang, Maia and Brabetz, Sebastian and Bender, Sebastian and Hutter, Barbara and Sturm, Dominik and Pfaff, Elke and H{\"u}bschmann, Daniel and Zipprich, Gideon and Heinold, Michael and Eils, J{\"u}rgen and Lawerenz, Christian and Erkek, Serap and Lambo, Sander and Waszak, Sebastian and Blattmann, Claudia and Borkhardt, Arndt and Kuhlen, Michaela and Eggert, Angelika and Fulda, Simone and Gessler, Manfred and Wegert, Jenny and Kappler, Roland and Baumhoer, Daniel and Stefan, Burdach and Kirschner-Schwabe, Renate and Kontny, Udo and Kulozik, Andreas E. and Lohmann, Dietmar and Hettmer, Simone and Eckert, Cornelia and Bielack, Stefan and Nathrath, Michaela and Niemeyer, Charlotte and Richter, G{\"u}nther H. and Schulte, Johannes and Siebert, Reiner and Westermann, Frank and Molenaar, Jan J. and Vassal, Gilles and Witt, Hendrik and Burkhardt, Birgit and Kratz, Christian P. and Witt, Olaf and van Tilburg, Cornelis M. and Kramm, Christof M. and Fleischhack, Gudrun and Dirksen, Uta and Rutkowski, Stefan and Fr{\"u}hwald, Michael and Hoff, Katja von and Wolf, Stephan and Klingebeil, Thomas and Koscielniak, Ewa and Landgraf, Pablo and Koster, Jan and Resnick, Adam C. and Zhang, Jinghui and Liu, Yanling and Zhou, Xin and Waanders, Angela J. and Zwijnenburg, Danny A. and Raman, Pichai and Brors, Benedikt and Weber, Ursula D. and Northcott, Paul A. and Pajtler, Kristian W. and Kool, Marcel and Piro, Rosario M. and Korbel, Jan O. and Schlesner, Matthias and Eils, Roland and Jones, David T. W. and Lichter, Peter and Chavez, Lukas and Zapatka, Marc and Pfister, Stefan M.}, title = {The landscape of genomic alterations across childhood cancers}, series = {Nature}, volume = {555}, journal = {Nature}, organization = {ICGC PedBrain-Seq Project, ICGC MMML-Seq Project,}, doi = {10.1038/nature25480}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229579}, pages = {321-327}, year = {2018}, abstract = {Pan-cancer analyses that examine commonalities and differences among various cancer types have emerged as a powerful way to obtain novel insights into cancer biology. Here we present a comprehensive analysis of genetic alterations in a pan-cancer cohort including 961 tumours from children, adolescents, and young adults, comprising 24 distinct molecular types of cancer. Using a standardized workflow, we identified marked differences in terms of mutation frequency and significantly mutated genes in comparison to previously analysed adult cancers. Genetic alterations in 149 putative cancer driver genes separate the tumours into two classes: small mutation and structural/copy-number variant (correlating with germline variants). Structural variants, hyperdiploidy, and chromothripsis are linked to TP53 mutation status and mutational signatures. Our data suggest that 7-8\% of the children in this cohort carry an unambiguous predisposing germline variant and that nearly 50\% of paediatric neoplasms harbour a potentially druggable event, which is highly relevant for the design of future clinical trials.}, language = {en} } @article{GiampaoloWojcikKleinHesslingetal.2019, author = {Giampaolo, Sabrina and W{\´o}jcik, Gabriela and Klein-Hessling, Stefan and Serfling, Edgar and Patra, Amiya K.}, title = {B cell development is critically dependent on NFATc1 activity}, series = {Cellular \& Molecular Immunology}, volume = {16}, journal = {Cellular \& Molecular Immunology}, doi = {10.1038/s41423-018-0052-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233006}, pages = {508-520}, year = {2019}, abstract = {B cell development in bone marrow is a precisely regulated complex process. Through successive stages of differentiation, which are regulated by a multitude of signaling pathways and an array of lineage-specific transcription factors, the common lymphoid progenitors ultimately give rise to mature B cells. Similar to early thymocyte development in the thymus, early B cell development in bone marrow is critically dependent on IL-7 signaling. During this IL-7-dependent stage of differentiation, several transcription factors, such as E2A, EBF1, and Pax5, among others, play indispensable roles in B lineage specification and maintenance. Although recent studies have implicated several other transcription factors in B cell development, the role of NFATc1 in early B cell developmental stages is not known. Here, using multiple gene-manipulated mouse models and applying various experimental methods, we show that NFATc1 activity is vital for early B cell differentiation. Lack of NFATc1 activity in pro-B cells suppresses EBF1 expression, impairs immunoglobulin gene rearrangement, and thereby preBCR formation, resulting in defective B cell development. Overall, deficiency in NFATc1 activity arrested the pro-B cell transition to the pre-B cell stage, leading to severe B cell lymphopenia. Our findings suggest that, along with other transcription factors, NFATc1 is a critical component of the signaling mechanism that facilitates early B cell differentiation.}, language = {en} } @article{LopezKleinheinzAukemaetal.2019, author = {L{\´o}pez, Cristina and Kleinheinz, Kortine and Aukema, Sietse M. and Rohde, Marius and Bernhart, Stephan H. and H{\"u}bschmann, Daniel and Wagener, Rabea and Toprak, Umut H. and Raimondi, Francesco and Kreuz, Markus and Waszak, Sebastian M. and Huang, Zhiqin and Sieverling, Lina and Paramasivam, Nagarajan and Seufert, Julian and Sungalee, Stephanie and Russell, Robert B. and Bausinger, Julia and Kretzmer, Helene and Ammerpohl, Ole and Bergmann, Anke K. and Binder, Hans and Borkhardt, Arndt and Brors, Benedikt and Claviez, Alexander and Doose, Gero and Feuerbach, Lars and Haake, Andrea and Hansmann, Martin-Leo and Hoell, Jessica and Hummel, Michael and Korbel, Jan O. and Lawerenz, Chris and Lenze, Dido and Radlwimmer, Bernhard and Richter, Julia and Rosenstiel, Philip and Rosenwald, Andreas and Schilhabel, Markus B. and Stein, Harald and Stilgenbauer, Stephan and Stadler, Peter F. and Szczepanowski, Monika and Weniger, Marc A. and Zapatka, Marc and Eils, Roland and Lichter, Peter and Loeffler, Markus and M{\"o}ller, Peter and Tr{\"u}mper, Lorenz and Klapper, Wolfram and Hoffmann, Steve and K{\"u}ppers, Ralf and Burkhardt, Birgit and Schlesner, Matthias and Siebert, Reiner}, title = {Genomic and transcriptomic changes complement each other in the pathogenesis of sporadic Burkitt lymphoma}, series = {Nature Communications}, volume = {10}, journal = {Nature Communications}, organization = {ICGC MMML-Seq Consortium}, doi = {10.1038/s41467-019-08578-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-237281}, year = {2019}, abstract = {Burkitt lymphoma (BL) is the most common B-cell lymphoma in children. Within the International Cancer Genome Consortium (ICGC), we performed whole genome and transcriptome sequencing of 39 sporadic BL. Here, we unravel interaction of structural, mutational, and transcriptional changes, which contribute to MYC oncogene dysregulation together with the pathognomonic IG-MYC translocation. Moreover, by mapping IGH translocation breakpoints, we provide evidence that the precursor of at least a subset of BL is a B-cell poised to express IGHA. We describe the landscape of mutations, structural variants, and mutational processes, and identified a series of driver genes in the pathogenesis of BL, which can be targeted by various mechanisms, including IG-non MYC translocations, germline and somatic mutations, fusion transcripts, and alternative splicing.}, language = {en} } @article{SolimandoBrandlMattenheimeretal.2018, author = {Solimando, A G and Brandl, A and Mattenheimer, K and Graf, C and Ritz, M and Ruckdeschel, A and St{\"u}hmer, T and Mokhtari, Z and Rudelius, M and Dotterweich, J and Bittrich, M and Desantis, V and Ebert, R and Trerotoli, P and Frassanito, M A and Rosenwald, A and Vacca, A and Einsele, H and Jakob, F and Beilhack, A}, title = {JAM-A as a prognostic factor and new therapeutic target in multiple myeloma}, series = {Leukemia}, volume = {32}, journal = {Leukemia}, doi = {10.1038/leu.2017.287}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239069}, pages = {736-743}, year = {2018}, abstract = {Cell adhesion in the multiple myeloma (MM) microenvironment has been recognized as a major mechanism of MM cell survival and the development of drug resistance. Here we addressed the hypothesis that the protein junctional adhesion molecule-A (JAM-A) may represent a novel target and a clinical biomarker in MM. We evaluated JAM-A expression in MM cell lines and in 147 MM patient bone marrow aspirates and biopsies at different disease stages. Elevated JAM-A levels in patient-derived plasma cells were correlated with poor prognosis. Moreover, circulating soluble JAM-A (sJAM-A) levels were significantly increased in MM patients as compared with controls. Notably, in vitro JAM-A inhibition impaired MM migration, colony formation, chemotaxis, proliferation and viability. In vivo treatment with an anti-JAM-A monoclonal antibody (αJAM-A moAb) impaired tumor progression in a murine xenograft MM model. These results demonstrate that therapeutic targeting of JAM-A has the potential to prevent MM progression, and lead us to propose JAM-A as a biomarker in MM, and sJAM-A as a serum-based marker for clinical stratification.}, language = {en} } @article{WegertVokuhlCollordetal.2018, author = {Wegert, Jenny and Vokuhl, Christian and Collord, Grace and Del Castillo Velasco-Herrera, Martin and Farndon, Sarah J. and Guzzo, Charlotte and Jorgensen, Mette and Anderson, John and Slater, Olga and Duncan, Catriona and Bausenwein, Sabrina and Streitenberger, Heike and Ziegler, Barbara and Furtw{\"a}ngler, Rhoikos and Graf, Norbert and Stratton, Michael R. and Campbell, Peter J. and Jones, David TW and Koelsche, Christian and Pfister, Stefan M. and Mifsud, William and Sebire, Neil and Sparber-Sauer, Monika and Koscielniak, Ewa and Rosenwald, Andreas and Gessler, Manfred and Behjati, Sam}, title = {Recurrent intragenic rearrangements of EGFR and BRAF in soft tissue tumors of infants}, series = {Nature Communications}, volume = {9}, journal = {Nature Communications}, doi = {10.1038/s41467-018-04650-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233446}, year = {2018}, abstract = {Soft tissue tumors of infancy encompass an overlapping spectrum of diseases that pose unique diagnostic and clinical challenges. We studied genomes and transcriptomes of cryptogenic congenital mesoblastic nephroma (CMN), and extended our findings to five anatomically or histologically related soft tissue tumors: infantile fibrosarcoma (IFS), nephroblastomatosis, Wilms tumor, malignant rhabdoid tumor, and clear cell sarcoma of the kidney. A key finding is recurrent mutation of EGFR in CMN by internal tandem duplication of the kinase domain, thus delineating CMN from other childhood renal tumors. Furthermore, we identify BRAF intragenic rearrangements in CMN and IFS. Collectively these findings reveal novel diagnostic markers and therapeutic strategies and highlight a prominent role of isolated intragenic rearrangements as drivers of infant tumors.}, language = {en} } @phdthesis{Pickert2024, author = {Pickert, Julia Felicia}, title = {Untersuchungen zum Einfluss des Insulin-like growth factor Rezeptors auf Signalnetzwerke im Multiplen Myelom}, doi = {10.25972/OPUS-36981}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-369815}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Das MM ist eine maligne Erkrankung, die von biologischer und klinischer Heterogenit{\"a}t gepr{\"a}gt ist. Sie ist durch die monoklonale Vermehrung von Plasmazellen charakterisiert. In vorangegangenen Studien wurde eine H{\"a}ufung von Mutationen in RTK nachgewiesen. Diese gingen mit einem negativen Einfluss auf das {\"U}berleben von MM Patientinnen und Patienten einher. Im Rahmen dieser Arbeit wurde der Einfluss des IGF1R an HMZL mittels siRNA-vermitteltem IGF1R-Knockdown untersucht und dessen Effekt auf das Signalnetzwerk mittels Western Blot Analysen ermittelt. Um die Heterogenit{\"a}t des MM besser abzubilden, wurden sechs verschiedenen HMZL ausgew{\"a}hlt. Der IGF1R-Knockdown war in allen HMZL sowohl anhand der Reduktion der IGF1R-Expression als auch der IGF1R-Aktivierung deutlich nachweisbar. Stellvertretend f{\"u}r den PI3K/AKT Signalweg wurde die AKT-Aktivierung untersucht, welche nach IGF1R-Knockdown in allen Linien abnahm. Im Ras/Raf/MEK/ERK Signalweg fiel eine deutliche Reduktion der ERK1/2- und MEK-Aktivierung in den von PCL stammenden HMZL L-363 und MM.1S, sowie in JJN-3 mit der Hochrisikotranslokation t(14;16) auf. Entsprechend der Beobachtungen f{\"u}r die AKT-Aktivierung, nahm die PYK2-Aktivierung in allen HMZL nach IGF1R-Knockdown ab, was auf ein Zusammenspiel von IGF1R, PYK2 und AKT in allen HMZL hindeutet. Zuk{\"u}nftige Untersuchungen werden zeigen, ob IGF1R Inhibitoren alleine oder in Kombination mit z.B. AKT, PYK2 oder Proteasomen-Inhibitoren in bestimmten molekularen MM Subgruppen ein effektives therapeutisches Ziel sind.}, subject = {Plasmozytom}, language = {de} }