RAF inhibitor PLX8394 selectively disrupts BRAF dimers and RAS-independent BRAF-mutant-driven signaling Research Letter


Authors: Yao, Z.; Gao, Y.; Su, W.; Yaeger, R.; Tao, J.; Na, N.; Zhang, Y.; Zhang, C.; Rymar, A.; Tao, A.; Timaul, N. M.; McGriskin, R.; Outmezguine, N. A.; Zhao, H.; Chang, Q.; Qeriqi, B.; Barbacid, M.; de Stanchina, E.; Hyman, D. M.; Bollag, G.; Rosen, N.
Title: RAF inhibitor PLX8394 selectively disrupts BRAF dimers and RAS-independent BRAF-mutant-driven signaling
Abstract: Activating BRAF mutants and fusions signal as RAS-independent constitutively active dimers with the exception of BRAF V600 mutant alleles which can function as active monomers 1 . Current RAF inhibitors are monomer selective, they potently inhibit BRAF V600 monomers but their inhibition of RAF dimers is limited by induction of negative cooperativity when bound to one site in the dimer 1–3 . Moreover, acquired resistance to these drugs is usually due to molecular lesions that cause V600 mutants to dimerize 4–8 . We show here that PLX8394, a new RAF inhibitor 9 , inhibits ERK signaling by specifically disrupting BRAF-containing dimers, including BRAF homodimers and BRAF–CRAF heterodimers, but not CRAF homodimers or ARAF-containing dimers. Differences in the amino acid residues in the amino (N)-terminal portion of the kinase domain of RAF isoforms are responsible for this differential vulnerability. As a BRAF-specific dimer breaker, PLX8394 selectively inhibits ERK signaling in tumors driven by dimeric BRAF mutants, including BRAF fusions and splice variants as well as BRAF V600 monomers, but spares RAF function in normal cells in which CRAF homodimers can drive signaling. Our work suggests that drugs with these properties will be safe and useful for treating tumors driven by activating BRAF mutants or fusions. © 2018, The Author(s), under exclusive licence to Springer Nature America, Inc.
Journal Title: Nature Medicine
Volume: 25
Issue: 2
ISSN: 1078-8956
Publisher: Nature Publishing Group  
Date Published: 2019-02-01
Start Page: 284
End Page: 291
Language: English
DOI: 10.1038/s41591-018-0274-5
PUBMED: 30559419
PROVIDER: scopus
PMCID: PMC6404779
DOI/URL:
Notes: Letter -- Export Date: 1 March 2019 -- Source: Scopus
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MSK Authors
  1. Neal Rosen
    425 Rosen
  2. Rona Denit Yaeger
    315 Yaeger
  3. David Hyman
    354 Hyman
  4. Qing Chang
    36 Chang
  5. Zhan Yao
    38 Yao
  6. Wenjing Su
    11 Su
  7. Neilawattie Merna Torres
    18 Torres
  8. Yijun   Gao
    11 Gao
  9. HuiYong   Zhao
    25 Zhao
  10. Jessica Jing Tao
    11 Tao
  11. Besnik Qeriqi
    15 Qeriqi
  12. Na Na
    6 Na