@article{JessenKressBaluapurietal.2020,
  author    = {Jessen, Christina and Kreß, Julia K. C. and Baluapuri, Apoorva and Hufnagel, Anita and Schmitz, Werner and Kneitz, Susanne and Roth, Sabine and Marquardt, Andr{\´e} and Appenzeller, Silke and Ade, Casten P. and Glutsch, Valerie and Wobser, Marion and Friedmann-Angeli, Jos{\´e} Pedro and Mosteo, Laura and Goding, Colin R. and Schilling, Bastian and Geissinger, Eva and Wolf, Elmar and Meierjohann, Svenja},
  title     = {The transcription factor NRF2 enhances melanoma malignancy by blocking differentiation and inducing COX2 expression},
  series = {Oncogene},
  volume    = {39},
  journal   = {Oncogene},
  issn      = {0950-9232},
  doi       = {10.1038/s41388-020-01477-8},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-235064},
  pages     = {6841-6855},
  year      = {2020},
  abstract  = {The transcription factor NRF2 is the major mediator of oxidative stress responses and is closely connected to therapy resistance in tumors harboring activating mutations in the NRF2 pathway. In melanoma, such mutations are rare, and it is unclear to what extent melanomas rely on NRF2. Here we show that NRF2 suppresses the activity of the melanocyte lineage marker MITF in melanoma, thereby reducing the expression of pigmentation markers. Intriguingly, we furthermore identified NRF2 as key regulator of immune-modulating genes, linking oxidative stress with the induction of cyclooxygenase 2 (COX2) in an ATF4-dependent manner. COX2 is critical for the secretion of prostaglandin E2 and was strongly induced by H\(_2\)O\(_2\) or TNFα only in presence of NRF2. Induction of MITF and depletion of COX2 and PGE2 were also observed in NRF2-deleted melanoma cells in vivo. Furthermore, genes corresponding to the innate immune response such as RSAD2 and IFIH1 were strongly elevated in absence of NRF2 and coincided with immune evasion parameters in human melanoma datasets. Even in vitro, NRF2 activation or prostaglandin E2 supplementation blunted the induction of the innate immune response in melanoma cells. Transcriptome analyses from lung adenocarcinomas indicate that the observed link between NRF2 and the innate immune response is not restricted to melanoma.},
  language  = {en}
}
@article{MeinertJessenHufnageletal.2024,
  author    = {Meinert, Madlen and Jessen, Christina and Hufnagel, Anita and Kreß, Julia Katharina Charlotte and Burnworth, Mychal and D{\"a}ubler, Theo and Gallasch, Till and Da Xavier Silva, Thamara Nishida and Dos Santos, Anc{\´e}ly Ferreira and Ade, Carsten Patrick and Schmitz, Werner and Kneitz, Susanne and Friedmann Angeli, Jos{\´e} Pedro and Meierjohann, Svenja},
  title     = {Thiol starvation triggers melanoma state switching in an ATF4 and NRF2-dependent manner},
  series = {Redox Biology},
  volume    = {70},
  journal   = {Redox Biology},
  doi       = {10.1016/j.redox.2023.103011},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350328},
  year      = {2024},
  abstract  = {The cystine/glutamate antiporter xCT is an important source of cysteine for cancer cells. Once taken up, cystine is reduced to cysteine and serves as a building block for the synthesis of glutathione, which efficiently protects cells from oxidative damage and prevents ferroptosis. As melanomas are particularly exposed to several sources of oxidative stress, we investigated the biological role of cysteine and glutathione supply by xCT in melanoma. xCT activity was abolished by genetic depletion in the Tyr::CreER; Braf\(^{CA}\); Pten\(^{lox/+}\) melanoma model and by acute cystine withdrawal in melanoma cell lines. Both interventions profoundly impacted melanoma glutathione levels, but they were surprisingly well tolerated by murine melanomas in vivo and by most human melanoma cell lines in vitro. RNA sequencing of human melanoma cells revealed a strong adaptive upregulation of NRF2 and ATF4 pathways, which orchestrated the compensatory upregulation of genes involved in antioxidant defence and de novo cysteine biosynthesis. In addition, the joint activation of ATF4 and NRF2 triggered a phenotypic switch characterized by a reduction of differentiation genes and induction of pro-invasive features, which was also observed after erastin treatment or the inhibition of glutathione synthesis. NRF2 alone was capable of inducing the phenotypic switch in a transient manner. Together, our data show that cystine or glutathione levels regulate the phenotypic plasticity of melanoma cells by elevating ATF4 and NRF2.},
  language  = {en}
}