TY  - JOUR
A1  - Kreß, Julia Katharina Charlotte
A1  - Jessen, Christina
A1  - Marquardt, André
A1  - Hufnagel, Anita
A1  - Meierjohann, Svenja
T1  - NRF2 enables EGFR signaling in melanoma cells
JF  - International Journal of Molecular Sciences
N2  - 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.
KW  - EGFR
KW  - NRF2
KW  - NFE2L2
KW  - KEAP1
KW  - MITF-low
KW  - TGF-alpha
KW  - EGF
KW  - NSCLC
KW  - HNSC
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260222
SN  - 1422-0067
VL  - 22
IS  - 8
ER  - 
TY  - JOUR
A1  - Jessen, Christina
A1  - Kreß, Julia K. C.
A1  - Baluapuri, Apoorva
A1  - Hufnagel, Anita
A1  - Schmitz, Werner
A1  - Kneitz, Susanne
A1  - Roth, Sabine
A1  - Marquardt, André
A1  - Appenzeller, Silke
A1  - Ade, Casten P.
A1  - Glutsch, Valerie
A1  - Wobser, Marion
A1  - Friedmann-Angeli, José Pedro
A1  - Mosteo, Laura
A1  - Goding, Colin R.
A1  - Schilling, Bastian
A1  - Geissinger, Eva
A1  - Wolf, Elmar
A1  - Meierjohann, Svenja
T1  - The transcription factor NRF2 enhances melanoma malignancy by blocking differentiation and inducing COX2 expression
JF  - Oncogene
N2  - 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.
KW  - NRF2
KW  - melanoma malignancy
KW  - COX2 expression
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235064
SN  - 0950-9232
VL  - 39
ER  -