@article{KepplerWeissbachLangeretal.2016,
  author    = {Keppler, Sarah and Weißbach, Susann and Langer, Christian and Knop, Stefan and Pischimarov, Jordan and Kull, Miriam and St{\"u}hmer, Thorsten and Steinbrunn, Torsten and Bargou, Ralf and Einsele, Hermann and Rosenwald, Andreas and Leich, Ellen},
  title     = {Rare SNPs in receptor tyrosine kinases are negative outcome predictors in multiple myeloma},
  series = {Oncotarget},
  volume    = {7},
  journal   = {Oncotarget},
  number    = {25},
  doi       = {10.18632/oncotarget.9607},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177840},
  pages     = {38762-38774},
  year      = {2016},
  abstract  = {Multiple myeloma (MM) is a plasma cell disorder that is characterized by a great genetic heterogeneity. Recent next generation sequencing studies revealed an accumulation of tumor-associated mutations in receptor tyrosine kinases (RTKs) which may also contribute to the activation of survival pathways in MM. To investigate the clinical role of RTK-mutations in MM, we deep-sequenced the coding DNA-sequence of EGFR, EPHA2, ERBB3, IGF1R, NTRK1 and NTRK2 which were previously found to be mutated in MM, in 75 uniformly treated MM patients of the "Deutsche Studiengruppe Multiples Myelom". Subsequently, we correlated the detected mutations with common cytogenetic alterations and clinical parameters. We identified 11 novel non-synonymous SNVs or rare patient-specific SNPs, not listed in the SNP databases 1000 genomes and dbSNP, in 10 primary MM cases. The mutations predominantly affected the tyrosine-kinase and ligand-binding domains and no correlation with cytogenetic parameters was found. Interestingly, however, patients with RTK-mutations, specifically those with rare patient-specific SNPs, showed a significantly lower overall, event-free and progression-free survival. This indicates that RTK SNVs and rare patient-specific RTK SNPs are of prognostic relevance and suggests that MM patients with RTK-mutations could potentially profit from treatment with RTK-inhibitors.},
  language  = {en}
}
@article{SteinbrunnChatterjeeBargouetal.2014,
  author    = {Steinbrunn, Torsten and Chatterjee, Manik and Bargou, Ralf C. and St{\"u}hmer, Thorsten},
  title     = {Efficient Transient Transfection of Human Multiple Myeloma Cells by Electroporation - An Appraisal},
  series = {PLoS ONE},
  volume    = {9},
  journal   = {PLoS ONE},
  number    = {6},
  doi       = {10.1371/journal.pone.0097443},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119616},
  pages     = {e97443},
  year      = {2014},
  abstract  = {Cell lines represent the everyday workhorses for in vitro research on multiple myeloma (MM) and are regularly employed in all aspects of molecular and pharmacological investigations. Although loss-of-function studies using RNA interference in MM cell lines depend on successful knockdown, no well-established and widely applied protocol for efficient transient transfection has so far emerged. Here, we provide an appraisal of electroporation as a means to introduce either short-hairpin RNA expression vectors or synthesised siRNAs into MM cells. We found that electroporation using siRNAs was much more efficient than previously anticipated on the basis of transfection efficiencies deduced from EGFP-expression off protein expression vectors. Such knowledge can even confidently be exploited in "hard-to-transfect" MM cell lines to generate large numbers of transient knockdown phenotype MM cells. In addition, special attention was given to developing a protocol that provides easy implementation, good reproducibility and manageable experimental costs.},
  language  = {en}
}
@article{RauertWunderlichSiegmundMaieretal.2013,
  author    = {Rauert-Wunderlich, Hilka and Siegmund, Daniela and Maier, Eduard and Giner, Tina and Bargou, Ralf C. and Wajant, Harald and St{\"u}hmer, Thorsten},
  title     = {The IKK Inhibitor Bay 11-7082 Induces Cell Death Independent from Inhibition of Activation of NF kappa B Transcription Factors},
  series = {PLoS ONE},
  volume    = {8},
  journal   = {PLoS ONE},
  number    = {3},
  doi       = {10.1371/journal.pone.0059292},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130140},
  pages     = {e59292},
  year      = {2013},
  abstract  = {Multiple myeloma (MM) displays an NFκB activity-related gene expression signature and about 20\% of primary MM samples harbor genetic alterations conducive to intrinsic NFκB signaling activation. The relevance of blocking the classical versus the alternative NFκB signaling pathway and the molecular execution mechanisms involved, however, are still poorly understood. Here, we comparatively tested NFκB activity abrogation through TPCA-1 (an IKK2 inhibitor), BAY 11-7082 (an IKK inhibitor poorly selective for IKK1 and IKK2), and MLN4924 (an NEDD8 activating enzyme (NAE)-inhibitor), and analyzed their anti-MM activity. Whereas TPCA-1 interfered selectively with activation of the classical NFκB pathway, the other two compounds inhibited classical and alternative NFκB signaling without significant discrimination. Noteworthy, whereas TPCA-1 and MLN4924 elicited rather mild anti-MM effects with slight to moderate cell death induction after 1 day BAY 11-7082 was uniformly highly toxic to MM cell lines and primary MM cells. Treatment with BAY 11-7082 induced rapid cell swelling and its initial effects were blocked by necrostatin-1 or the ROS scavenger BHA, but a lasting protective effect was not achieved even with additional blockade of caspases. Because MLN4924 inhibits the alternative NFκB pathway downstream of IKK1 at the level of p100 processing, the quite discordant effects between MLN4924 and BAY 11-7082 must thus be due to blockade of IKK1-mediated NFκB-independent necrosis-inhibitory functions or represent an off-target effect of BAY 11-7082. In accordance with the latter, we further observed that concomitant knockdown of IKK1 and IKK2 did not have any major short-term adverse effect on the viability of MM cells.},
  language  = {en}
}
@article{WeissbachHerediaGuerreroBarnsteineretal.2020,
  author    = {Weißbach, Susann and Heredia-Guerrero, Sofia Catalina and Barnsteiner, Stefanie and Großhans, Lukas and Bodem, Jochen and Starz, Hanna and Langer, Christian and Appenzeller, Silke and Knop, Stefan and Steinbrunn, Torsten and Rost, Simone and Einsele, Hermann and Bargou, Ralf Christian and Rosenwald, Andreas and St{\"u}hmer, Thorsten and Leich, Ellen},
  title     = {Exon-4 Mutations in KRAS Affect MEK/ERK and PI3K/AKT Signaling in Human Multiple Myeloma Cell Lines},
  series = {Cancers},
  volume    = {12},
  journal   = {Cancers},
  number    = {2},
  issn      = {2072-6694},
  doi       = {10.3390/cancers12020455},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200617},
  year      = {2020},
  abstract  = {Approximately 20\% of multiple myeloma (MM) cases harbor a point mutation in KRAS. However, there is still no final consent on whether KRAS-mutations are associated with disease outcome. Specifically, no data exist on whether KRAS-mutations have an impact on survival of MM patients at diagnosis in the era of novel agents. Direct blockade of KRAS for therapeutic purposes is mostly impossible, but recently a mutation-specific covalent inhibitor targeting KRAS\(^{p.G12C}\) entered into clinical trials. However, other KRAS hotspot-mutations exist in MM patients, including the less common exon-4 mutations. For the current study, the coding regions of KRAS were deep-sequenced in 80 newly diagnosed MM patients, uniformely treated with three cycles of bortezomib plus dexamethasone and cyclophosphamide (VCD)-induction, followed by high-dose chemotherapy and autologous stem cell transplantation. Moreover, the functional impact of KRAS\(^{p.G12A}\) and the exon-4 mutations p.A146T and p.A146V on different survival pathways was investigated. Specifically, KRAS\(^{WT}\), KRAS\(^{p.G12A}\), KRAS\(^{p.A146T}\), and KRAS\(^{p.A146V}\) were overexpressed in HEK293 cells and the KRAS\(^{WT}\) MM cell lines JJN3 and OPM2 using lentiviral transduction and the Sleeping Beauty vector system. Even though KRAS-mutations were not correlated with survival, all KRAS-mutants were found capable of potentially activating MEK/ERK- and sustaining PI3K/AKT-signaling in MM cells.},
  language  = {en}
}