A Role for Mitochondrial Translation in Promotion of Viability in K-Ras Mutant Cells

• DOI: 10.1016/j.celrep.2017.06.061
• Publication Date: 2017-07-11T18:31:53Z
• Authors: Timothy D. Martin; Danielle R. Cook; Mei Yuk Choi; Mamie Z. Li; Kevin M. Haigis; Stephen J. Elledge
• Keywords: 0301 basic medicine; QH301-705.5; oxidative phosphorylation; Minocycline; mitochondrial translation; Tigecycline; Cell Line; Mice; 03 medical and health sciences; shRNA; Proto-Oncogene Proteins; KRAS; Animals; Humans; Clustered Regularly Interspaced Short Palindromic Repeats; Biology (General); Cell Proliferation; mitoribosome; Mice, Inbred BALB C; 0303 health sciences; Hydrazones; NADH Dehydrogenase; Triazoles; HCT116 Cells; Xenograft Model Antitumor Assays; mitochondria; Genes, ras; synthetic lethal; CRISPR; genetic screen; Mutation; Female

Activating mutations in the KRAS oncogene are highly prevalent in tumors, especially those of the colon, lung, and pancreas. To better understand the genetic dependencies that K-Ras mutant cells rely upon for their growth, we employed whole-genome CRISPR loss-of-function screens in two isogenic pairs of cell lines. Since loss of essential genes is uniformly toxic in CRISPR-based screens, we also developed a small hairpin RNA (shRNA) library targeting essential genes. These approaches uncovered a large set of proteins whose loss results in the selective reduction of K-Ras mutant cell growth. Pathway analysis revealed that many of these genes function in the mitochondria. For validation, we generated isogenic pairs of cell lines using CRISPR-based genome engineering, which confirmed the dependency of K-Ras mutant cells on these mitochondrial pathways. Finally, we found that mitochondrial inhibitors reduce the growth of K-Ras mutant tumors in vivo, aiding in the advancement of strategies to target K-Ras-driven malignancy.