PT - JOURNAL ARTICLE AU - Angel A. Ku AU - Sameera Kongara AU - Hsien-Ming Hu AU - Xin Zhao AU - Di Wu AU - Frank McCormick AU - Allan Balmain AU - Sourav Bandyopadhyay TI - Integration of pathway, cellular and genetic context reveals principles of synthetic lethality that affect reproducibility AID - 10.1101/591677 DP - 2019 Jan 01 TA - bioRxiv PG - 591677 4099 - http://biorxiv.org/content/early/2019/03/27/591677.short 4100 - http://biorxiv.org/content/early/2019/03/27/591677.full AB - Synthetic lethal screens have the potential to identify new vulnerabilities incurred by specific cancer mutations but have been hindered by lack of agreement between studies. Using KRAS as a model, we identified that published synthetic lethal screens significantly overlap at the pathway rather than gene level. Analysis of pathways encoded as protein networks identified synthetic lethal candidates that were more reproducible than those previously reported. Lack of overlap likely stems from biological rather than technical limitations as most synthetic lethal phenotypes were strongly modulated by changes in cellular conditions or genetic context, the latter determined using a pairwise genetic interaction map that identified numerous interactions that suppress synthetic lethal effects. Accounting for pathway, cellular and genetic context nominates a DNA repair dependency in KRAS-mutant cells, mediated by a network containing BRCA1. We provide evidence for why most reported synthetic lethals are not reproducible which is addressable using a multi-faceted testing framework.STATEMENT OF SIGNIFICANCESynthetic lethal screens have the power to identify new targets in cancer, although have thus far come up short of expectation. We use computational and experimental approaches to delineate principles for identifying robust synthetic lethal targets that could aid in the development of effective new therapeutic strategies for genetically defined cancers.