Generation of Protein Inhibitors for Validation of Cancer Drug Targets Identified in Functional Genomic Screens.

Functional genomic screens can identify several proteins as potential targets for drug development in cancer. Typically, these drug targets are validated with pharmacological inhibition using small molecules. Given that chemical inhibitors do not exist for a many of these proteins, several promising candidates often remain unexplored. In this chapter, we describe methods for generating protein-based inhibitors of intracellular targets using phage display. This is a scalable and inexpensive approach that can be applied to several protein targets identified in genetic screens. We describe methods for expression of target proteins, construction of phage-display libraries and selection of binding proteins. These synthetic binding proteins can block natural protein interactions within the cancer cell and act as inhibitors. Protein inhibitors have utility in validation of drug targets and can also guide small-molecule drug development.