Genetic mechanisms of resistance to targeted KRAS inhibition

Diaz, B. J.; Kops, M.; Bernardo, S.; Schmidt, H.; Grankowsky, E.; Vega, A.; Zhang, C.; Bott, M.; Skamagki, M.; Tomlinson, A.; Vita, N. A.; Katti, A.; Labrecque, M. P.; Aronchik, I.; Singh, M.; Dow, L. E.

doi:10.1101/2025.08.04.668444

bioRxiv · 10.1101/2025.08.04.668444

Genetic mechanisms of resistance to targeted KRAS inhibition

Diaz, B. J.·Kops, M.·Bernardo, S.·Schmidt, H.·Grankowsky, E.·Vega, A.·Zhang, C.·Bott, M.·Skamagki, M.·Tomlinson, A.·Vita, N. A.·Katti, A.·Labrecque, M. P.·Aronchik, I.·Singh, M.·Dow, L. E.

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Abstract

KRAS mutations are among the most prevalent oncogenic drivers in non-small cell lung cancer (NSCLC), yet the mechanisms of therapeutic resistance to KRAS inhibitors in these cancers remains poorly understood. Here, we deploy high-throughput CRISPR base editing screens to systematically map resistance mutations to three mechanistically distinct KRAS-targeted therapies, including KRAS-G12C(OFF) inhibitor (adagrasib), RAS(ON) G12C-selective tri-complex inhibitor (RMC-4998), and RAS(ON) multi-selective tri-complex inhibitor (RMC-7977). Using both a saturation Kras tiling approach and cancer-associated mutation library, we identify common and compound-selective second-site resistance mutations in Kras, as well as gain-of-function and loss-of-function variants across cancer-associated genes that rewire signaling networks in a context-dependent manner. Notably, we identify a recurrent missense mutation in capicua (Cic), that promotes resistance to RMC-7977 in vitro and in vivo. Moreover, we show that targeting NF{kappa}B signaling in CIC-mutant cells can resensitize them to RAS pathway inhibition and overcome resistance.

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Diaz, B. J., Kops, M., Bernardo, S., Schmidt, H., Grankowsky, E., Vega, A., Zhang, C., Bott, M., Skamagki, M., Tomlinson, A., Vita, N. A., Katti, A., Labrecque, M. P., Aronchik, I., Singh, M., Dow, L. E.. 2025-08-04. Genetic mechanisms of resistance to targeted KRAS inhibition. https://doi.org/10.1101/2025.08.04.668444

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