English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Melanoma resistant to MAPK inhibitors (MAPKi) displays loss of fitness upon experimental MAPKi withdrawal and, clinically, may be resensitized to MAPKi therapy after a drug holiday. Here, we uncovered and therapeutically exploited the mechanisms of MAPKi addiction in MAPKi-resistant BRAF MUT  or NRAS  MUT melanoma. MAPKi-addiction phenotypes evident upon drug withdrawal spanned transient cell-cycle slowdown to cell-death responses, the latter of which required a robust phosphorylated ERK (pERK) rebound. Generally, drug withdrawal-induced pERK rebound upregulated p38-FRA1-JUNB-CDKN1A and downregulated proliferation, but only a robust pERK rebound resulted in DNA damage and parthanatos-related cell death. Importantly, pharmacologically impairing DNA damage repair during MAPKi withdrawal augmented MAPKi addiction across the board by converting a cell-cycle deceleration to a caspase-dependent cell-death response or by furthering parthanatos-related cell death. Specifically in MEKi-resistant NRAS MUT  or atypical BRAF  MUT melanoma, treatment with a type I RAF inhibitor intensified pERK rebound elicited by MEKi withdrawal, thereby promoting a cell death-predominant MAPKi-addiction phenotype. Thus, MAPKi discontinuation upon disease progression should be coupled with specific strategies that augment MAPKi addiction. Significance: Discontinuing targeted therapy may select against drug-resistant tumor clones, but drug-addiction mechanisms are ill-defined. Using melanoma resistant to but withdrawn from MAPKi, we defined a synthetic lethality between supraphysiologic levels of pERK and DNA damage. Actively promoting this synthetic lethality could rationalize sequential/rotational regimens that address evolving vulnerabilities. Cancer Discov; 8(1); 74-93. ©2017 AACR.  See related commentary by Stern, p. 20  This article is highlighted in the In This Issue feature, p. 1 .

Exploiting Drug Addiction Mechanisms to Select against MAPKi-Resistant Melanoma