The Barcode System: A Robust In Vivo Genetic Manipulation Technique to Evaluate Essential Tumorigenic Genes

The conventional method to evaluate a gene’s role in tumor formation involves targeting a gene in one population of cancer cells, grafting those cells into an organism and examining whether tumor growth is altered compared to controls. Readouts for such experiments are qualitative and observational. This method carries several scientific caveats that make it difficult to elucidate the role of genetic manipulations in tumor formation, including the inherent variation between mice and the lack of a quantitative readout. Therefore, much progress in the field of gene therapy and curative cancer treatment research had been stunted because of the lack of an ideal method. Therefore, I designed a genetic manipulation system, alongside my mentor, to effectively allow for the study of the tumorigenic role of genes believed to be involved in cancer. In essence, this system, termed ‘the barcode system’ looks at growth po- tential at the cellular level instead of the organismal level. Rather than developing two populations of mice, we create two populations of cells, and inject them into a single mouse. This removes the variation of the conventional technique and introduces an internal con- trol into the system. Further, by measuring the relative growth of each cell population via a genetic tag, a barcode, we have introduced a quantitative readout. I will address the design of this system and its early pilot testing. We found that the barcode system is a highly sensitive system that is ideal for the identification of important genes.