TY  - JOUR
A1  - Fetiva, Maria Camila
A1  - Liss, Franziska
A1  - Gertzmann, Dörthe
A1  - Thomas, Julius
A1  - Gantert, Benedikt
A1  - Vogl, Magdalena
A1  - Sira, Nataliia
A1  - Weinstock, Grit
A1  - Kneitz, Susanne
A1  - Ade, Carsten P.
A1  - Gaubatz, Stefan
T1  - Oncogenic YAP mediates changes in chromatin accessibility and activity that drive cell cycle gene expression and cell migration
JF  - Nucleic Acids Research
N2  - YAP, the key protein effector of the Hippo pathway, is a transcriptional co-activator that controls the expression of cell cycle genes, promotes cell growth and proliferation and regulates organ size. YAP modulates gene transcription by binding to distal enhancers, but the mechanisms of gene regulation by YAP-bound enhancers remain poorly understood. Here we show that constitutive active YAP5SA leads to widespread changes in chromatin accessibility in untransformed MCF10A cells. Newly accessible regions include YAP-bound enhancers that mediate activation of cycle genes regulated by the Myb-MuvB (MMB) complex. By CRISPR-interference we identify a role for YAP-bound enhancers in phosphorylation of Pol II at Ser5 at MMB-regulated promoters, extending previously published studies that suggested YAP primarily regulates the pause-release step and transcriptional elongation. YAP5SA also leads to less accessible ‘closed’ chromatin regions, which are not directly YAP-bound but which contain binding motifs for the p53 family of transcription factors. Diminished accessibility at these regions is, at least in part, a consequence of reduced expression and chromatin-binding of the p53 family member ΔNp63 resulting in downregulation of ΔNp63-target genes and promoting YAP-mediated cell migration. In summary, our studies uncover changes in chromatin accessibility and activity that contribute to the oncogenic activities of YAP.
KW  - oncogenic YAP
KW  - chromatin
KW  - cell cycle
KW  - gene expression
KW  - cell migration
KW  - YAP5SA
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350218
VL  - 51
IS  - 9
ER  - 
TY  - JOUR
A1  - Meinert, Madlen
A1  - Jessen, Christina
A1  - Hufnagel, Anita
A1  - Kreß, Julia Katharina Charlotte
A1  - Burnworth, Mychal
A1  - Däubler, Theo
A1  - Gallasch, Till
A1  - Da Xavier Silva, Thamara Nishida
A1  - Dos Santos, Ancély Ferreira
A1  - Ade, Carsten Patrick
A1  - Schmitz, Werner
A1  - Kneitz, Susanne
A1  - Friedmann Angeli, José Pedro
A1  - Meierjohann, Svenja
T1  - Thiol starvation triggers melanoma state switching in an ATF4 and NRF2-dependent manner
JF  - Redox Biology
N2  - 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.
KW  - thiol starvation
KW  - ATF4
KW  - NRF2
KW  - melanoma
Y1  - 2024
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350328
VL  - 70
ER  -