Discovery of oncogenic ROS1 missense mutations with sensitivity to tyrosine kinase inhibitors

ROS1 is the largest receptor tyrosine kinase in the human genome. Rearrangements of the ROS1 gene result in oncogenic ROS1 kinase fusion proteins that are currently the only validated biomarkers for targeted therapy with ROS1 TKIs in patients. While numerous somatic missense mutations in ROS1 exist in the cancer genome, their impact on catalytic activity and pathogenic potential is unknown. We interrogated the AACR Genie database and identified 34 missense mutations in the ROS1 tyrosine kinase domain for further analysis. Our experiments revealed that these mutations have varying effects on ROS1 kinase function, ranging from complete loss to significantly increased catalytic activity. Notably, Asn and Gly substitutions at Asp2113 in the ROS1 kinase domain were found to be TKI-sensitive oncogenic variants in cell-based model systems. In vivo experiments showed that ROS1 D2113N induced tumor formation that was sensitive to crizotinib and lorlatinib, FDA-approved ROS1-TKIs. Collectively, these findings highlight the tumorigenic potential of specific point mutations within the ROS1 kinase domain and their potential as therapeutic targets with FDA-approved ROS1-TKIs.

Automated summary

ROS1 gene rearrangements result in oncogenic ROS1 kinase fusion proteins, which are currently the only validated biomarkers for targeted therapy with ROS1 TKIs. We identified 34 missense mutations in the ROS1 tyrosine kinase domain and found that they have varying effects on ROS1 kinase function, including loss and increased catalytic activity. Specific point mutations within the ROS1 kinase domain, such as Asn and Gly substitutions at Asp2113, were found to be TKI-sensitive oncogenic variants. These findings demonstrate the potential of targeting these mutations with FDA-approved ROS1-TKIs.