Lysine methylation promotes NFAT5 activation upon EGFR activation and predicts response to temozolomide

ABSTRACT: Temozolomide (TMZ) therapy offers minimal clinical benefits in patients with glioblastoma multiforme (GBM) with high EGFR activity, underscoring the need for effective combination therapy. Here, we show that tonicity-responsive enhancer binding protein (NFAT5) lysine methylation, is a determinant of TMZ response. Mechanistically, EGFR activation induces phosphorylated EZH2 (Ser21) binds and triggers NFAT5 methylation at K668. Methylation prevents NFAT5 cytoplasm interaction with E3 ligase TRAF6, thus blocks TRAF6 induced K63-linked ubiquitination mediated NFAT5 lysosomal degradation and cytosol localization restriction, result in NFAT5 protein stabilization, nuclear accumulation and activation. Methylated NFAT5 leads to the upregulation of MGMT, a transcriptional target of NFAT5, which is responsible for unfavorable TMZ response. Inhibition of NFAT5 K668 methylation improved TMZ efficacy in orthotopic xenografts and PDX models. Notably, NFAT5 K668 methylation levels are elevated in TMZ-refractory specimens and confer poor prognosis. Our findings suggest targeting NFAT5 methylation as an effective therapeutic strategy to improve TMZ response in tumors with EGFR activation.

ORGANISM(S): Homo Sapiens

SUBMITTER: Yu Ren  

PROVIDER: PXD037869 | iProX | Tue Nov 01 00:00:00 GMT 2022

REPOSITORIES: iProX