More than 200,000 Americans die as a result of lung and colorectal cancer each year. Decreasing the frequency of deaths due to these cancers will undoubtedly require tailoring an individual's treatment to the specific mutations that have occurred in their cancer. Activating mutations in the K-Ras oncoprotein are common in lung and colorectal cancers and are associated with particularly poor response to both conventional and targeted therapies. Our overarching goal is to understand the mechanisms underlying the oncogenic properties of mutant K-Ras in order to develop targeted therapeutic strategies. This project includes three phases. In the first phase of our project, we will use CRISPR technology to generate K-Ras wild-type derivatives of lung and colorectal cancer cells expressing endogenous mutant K-Ras. We will then comprehensively characterize the cellular and molecular phenotypes associated with loss of mutant K-Ras, for example by combining multiplexed mass spectrometry with computational modeling to identify the signal transduction network utilized by mutant K-Ras to transform cells. This study will also include an analysis of radiation response in wild-type and mutant cells, as activated K-Ras is known to confer resistance to ionizing radiation. In the second phase of our project, we will perform a variety of genome-wide and targeted screens for genes that when knocked down or over-expressed cause lethality in the context of mutant KRas in vitro and in vivo. These studies will utilize stat-of-the-art high-throughput screening technologies, including doxycycline-inducible shRNAs and open reading frames, that we have perfected over the past decade. In the final phase of the project, we will identify K-Ras synthetic lethals that are therapeutically targetable and then perform preclinical studies in genetically engineered mouse models of lung and colon cancer. The utilization of genetically controlled mouse and human experimental systems will allow us to identify gene products that are truly selectively required in cancer cells expressing mutant K-Ras. In the end, this work will have a major impact for patients who develop K-Ras mutant cancer.
Our overarching goal is to use isogenic K-Ras mutant and wild-type cancer cell lines to identify genetic dependencies that are specific to cells expressing activated K-Ras. Genome-wide and targeted knockdown and over-expression screens will be combined with detailed molecular and phenotypic analysis of isogenic cell line pairs in order to identify druggable targets that selective kill K-Ras mutant cells. Candidates identified through these integrated approaches will then be tested in preclinical therapy trials using genetically engineered mouse models of K-Ras driven lung and colon cancer.
| Haigis, Kevin M (2017) KRAS Alleles: The Devil Is in the Detail. Trends Cancer 3:686-697 |
| Martin, Timothy D; Cook, Danielle R; Choi, Mei Yuk et al. (2017) A Role for Mitochondrial Translation in Promotion of Viability in K-Ras Mutant Cells. Cell Rep 20:427-438 |
| Poulin, Emily J; Haigis, Kevin M (2017) No back seat for a progression event-K-RAS as a therapeutic target in CRC. Genes Dev 31:333-335 |
| Davoli, Teresa; Mengwasser, Kristen E; Duan, Jingjing et al. (2016) Functional genomics reveals that tumors with activating phosphoinositide 3-kinase mutations are dependent on accelerated protein turnover. Genes Dev 30:2684-2695 |
