FCCC LOGO Faculty Publications
Suppression of RAC1-driven malignant melanoma by group A PAK inhibitors
Oncogene. 2018 Feb 15;37(7) :944-952
PMID: 29059171    PMCID: PMC5814328    URL: https://www.ncbi.nlm.nih.gov/pubmed/29059171
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Activating mutations in the RAC1 gene have recently been discovered as driver events in malignant melanoma. Expression of this gene is associated with melanocyte proliferation, and melanoma cells bearing this mutation are insensitive to BRAF inhibitors such as vemurafenib and dabrafenib, and also may evade immune surveillance due to enhanced expression of PD-L1. Activating mutations in RAC1 are of special interest, as small-molecule inhibitors for the RAC effector p21-activated kinase (PAK) are in late-stage clinical development and might impede oncogenic signaling from mutant RAC1. In this work, we explore the effects of PAK inhibition on RAC1P29S signaling in zebrafish embryonic development, in the proliferation, survival and motility of RAC1P29S-mutant human melanoma cells, and on tumor formation and progression from such cells in mice. We report that RAC1P29S evokes a Rasopathy-like phenotype on zebrafish development that can be blocked by inhibitors of PAK or MEK. We also found and that RAC1-mutant human melanoma cells are resistant to clinical inhibitors of BRAF but are uniquely sensitive to PAK inhibitors. These data suggest that suppressing the PAK pathway might be of therapeutic benefit in this type of melanoma.Oncogene advance online publication, 23 October 2017; doi:10.1038/onc.2017.400.
1476-5594 Araiza-Olivera, D Feng, Y Semenova, G Prudnikova, T Y Rhodes, J Chernoff, J ORCID: http://orcid.org/0000-0002-4803-7836 Journal Article England Oncogene. 2017 Oct 23. doi: 10.1038/onc.2017.400.