Abstract 1780: iSCREAM - an unbiased pipeline to screen for activating kinase mutations

Abstract Cancer tissues harbor thousands of mutations, and a given oncogene may be mutated at hundreds of sites. Most of these somatic mutations are expected to be inconsequential passenger mutations that reflect the general instability of the tumors. The discovery of most of the currently known driver mutations has been facilitated by their accumulation in mutation hot-spots within their respective genes. However, a vast majority of mutations in cancer tissues are rare and no information is currently available about their functional significance. Several lines of in vitro and in vivo clinical evidence also indicate that there is a significant number of, as yet unidentified, activating driver mutations that could serve as predictive markers in oncology. An unbiased iSCREAM (in vitro screen for activating mutations) platform was developed to functionally characterize thousands of variants of a kinase oncogene in a single assay. The functional genetics screen was based on expressing random variants of a cDNA encoding a tyrosine kinase in a cell line in which the activating mutations provide growth-advantage. Targeted next-generation sequencing of the cDNA inserts was used to quantitatively analyze variants that provided growth-advantage. iSCREAM is able to identify activating mutations from a library of thousands of random mutations of a tyrosine kinase. The pipeline can also be modified to identify mutations conferring resistance to a tyrosine kinase inhibitor. Citation Format: Deepankar Chakroborty, Kari J. Kurppa, Ilkka Paatero, Laura L. Elo, Klaus Elenius. iSCREAM - an unbiased pipeline to screen for activating kinase mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1780.