@article {Gerosa762294, author = {Luca Gerosa and Christopher Chidley and Fabian Froehlich and Gabriela Sanchez and Sang Kyun Lim and Jeremy Muhlich and Jia-Yun Chen and Gregory J. Baker and Denis Schapiro and Tujin Shi and Lian Yi and Carrie D. Nicora and Allison Claas and Douglas A. Lauffenburger and Wei-Jun Qian and H. Steven Wiley and Peter K. Sorger}, title = {Sporadic ERK pulses drive non-genetic resistance in drug-adapted BRAFV600E melanoma cells}, elocation-id = {762294}, year = {2019}, doi = {10.1101/762294}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Anti-cancer drugs commonly target signal transduction proteins activated by mutation. In patients with BRAFV600E melanoma, small molecule RAF and MEK kinase inhibitors cause dramatic but often transient tumor regression. Emerging evidence suggests that cancer cells adapting by non-genetic mechanisms constitute a reservoir for the development of drug-resistant tumors. Here, we show that few hours after exposure to RAF/MEK inhibitors, BRAFV600E melanomas undergo adaptive changes involving disruption of negative feedback and sporadic pulsatile reactivation of the MAPK pathway, so that MAPK activity is transiently high enough in some cells to drive proliferation. Quantitative proteomics and computational modeling show that pulsatile MAPK reactivation is possible due to the co-existence in cells of two MAPK cascades: one driven by BRAFV600E that is drug-sensitive and a second driven by receptors that is drug-resistant. Paradoxically, this may account both for the frequent emergence of drug resistance and for the tolerability of RAF/MEK therapy in patients.}, URL = {https://www.biorxiv.org/content/early/2019/09/08/762294}, eprint = {https://www.biorxiv.org/content/early/2019/09/08/762294.full.pdf}, journal = {bioRxiv} }