@article{ZeinerZinkeKowalewskietal.2018,
  author    = {Zeiner, P. S. and Zinke, J. and Kowalewski, D. J. and Bernatz, S. and Tichy, J. and Ronellenfitsch, M. W. and Thorsen, F. and Berger, A. and Forster, M. T. and Muller, A. and Steinbach, J. P. and Beschorner, R. and Wischhusen, J. and Kvasnicka, H. M. and Plate, K. H. and Stefanović, S. and Weide, B. and Mittelbronn, M. and Harter, P. N.},
  title     = {CD74 regulates complexity of tumor cell HLA class II peptidome in brain metastasis and is a positive prognostic marker for patient survival},
  series = {Acta Neuropathologica Communications},
  volume    = {6},
  journal   = {Acta Neuropathologica Communications},
  doi       = {10.1186/s40478-018-0521-5},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233882},
  year      = {2018},
  abstract  = {Abstract Despite multidisciplinary local and systemic therapeutic approaches, the prognosis for most patients with brain metastases is still dismal. The role of adaptive and innate anti-tumor response including the Human Leukocyte Antigen (HLA) machinery of antigen presentation is still unclear. We present data on the HLA class II-chaperone molecule CD74 in brain metastases and its impact on the HLA peptidome complexity. We analyzed CD74 and HLA class II expression on tumor cells in a subset of 236 human brain metastases, primary tumors and peripheral metastases of different entities in association with clinical data including overall survival. Additionally, we assessed whole DNA methylome profiles including CD74 promoter methylation and differential methylation in 21 brain metastases. We analyzed the effects of a siRNA mediated CD74 knockdown on HLA-expression and HLA peptidome composition in a brain metastatic melanoma cell line. We observed that CD74 expression on tumor cells is a strong positive prognostic marker in brain metastasis patients and positively associated with tumor-infiltrating T-lymphocytes (TILs). Whole DNA methylome analysis suggested that CD74 tumor cell expression might be regulated epigenetically via CD74 promoter methylation. CD74\(^{high}\) and TIL\(^{high}\) tumors displayed a differential DNA methylation pattern with highest enrichment scores for antigen processing and presentation. Furthermore, CD74 knockdown in vitro lead to a reduction of HLA class II peptidome complexity, while HLA class I peptidome remained unaffected. In summary, our results demonstrate that a functional HLA class II processing machinery in brain metastatic tumor cells, reflected by a high expression of CD74 and a complex tumor cell HLA peptidome, seems to be crucial for better patient prognosis.},
  language  = {en}
}
@article{DiessnerBruttelSteinetal.2014,
  author    = {Diessner, J. and Bruttel, V. and Stein, R. G. and Horn, E. and H{\"a}usler, S. F. M. and Dietl, J. and H{\"o}nig, A. and Wischhusen, J.},
  title     = {Targeting of preexisting and induced breast cancer stem cells with trastuzumab and trastuzumab emtansine (T-DM1)},
  series = {Cell Death \& Disease},
  volume    = {5},
  journal   = {Cell Death \& Disease},
  issn      = {2041-4889},
  doi       = {10.1038/cddis.2014.115},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119884},
  pages     = {e1149},
  year      = {2014},
  abstract  = {The antibody trastuzumab (Herceptin) has substantially improved overall survival for patients with aggressive HER2-positive breast cancer. However, about 70\% of all treated patients will experience relapse or disease progression. This may be related to an insufficient targeting of the CD44(high)CD24(low) breast cancer stem cell subset, which is not only highly resistant to chemotherapy and radiotherapy but also a poor target for trastuzumab due to low HER2 surface expression. Hence, we explored whether the new antibody-drug conjugate T-DM1, which consists of the potent chemotherapeutic DM1 coupled to trastuzumab, could improve the targeting of these tumor-initiating or metastasis-initiating cells. To this aim, primary HER2-overexpressing tumor cells as well as HER2-positive and HER2-negative breast cancer cell lines were treated with T-DM1, and effects on survival, colony formation, gene and protein expression as well as antibody internalization were assessed. This revealed that CD44(high)CD24(low)HER2(low) stem cell-like breast cancer cells show high endocytic activity and are thus particularly sensitive towards the antibody-drug conjugate T-DM1. Consequently, preexisting CD44(high)CD24(low) cancer stem cells were depleted by concentrations of T-DM1 that did not affect the bulk of the tumor cells. Likewise, colony formation was efficiently suppressed. Moreover, when tumor cells were cocultured with natural killer cells, antibody-dependent cell-mediated cytotoxicity was enhanced, and EMT-mediated induction of stem cell-like properties was prevented in differentiated tumor cells. Thus our study reveals an unanticipated targeting of stem cell-like breast cancer cells by T-DM1 that may contribute to the clinical efficacy of this recently approved antibody-drug conjugate.},
  language  = {en}
}