The Quantitative Assay Database (QuAD) contains methods and reagents for monitoring cancer related signaling pathways and biological processes with mass spectrometry. The platform chosen for initial development is the coupling of SDS-PAGE with liquid chromatography coupled to multiple reaction monitoring (LC-MRM). However, additional information using other analytical platforms will be incorporated as the database grows. The purpose of the QuAD is to share methods and disseminate reagents for studying cancer biology to the scientific community, enabling both investigator-driven and hypothesis driven research using a platform that is portable from cell lines to limited amounts of clinical samples.

We have developed assays for targets from several different pathways that will enable assessment of cancer biology and drug response. For example, epidermal growth factor receptor (EGFR) signaling is of critical importance in a number of different tumors, including lung cancer. Apoptosis or programmed cell death is one example of a biological process that will be crucial to monitor in examining drug response and drug resistance. To date, ten pathways and processes (listed in the frame at the top left) have been investigated; approximately half of the assays that have been developed are contained in these pathways. Additional protein targets are listed on the index page, using their SwissProt accession numbers. While protein expression is the first goal, nested analysis of post-translational modifications is underway for a number of different proteins. These sets of assays have been developed as configurable modules that can be combined to build tools for systems biology assessment of cancer.

The database is organized at the level of the pathway or process, and data is presented on individual protein and peptide web pages. After selecting a pathway (at left), the icons for each protein can be selected to link to the protein page. Peptides that have passed initial LC-MRM screens are presented as links in the protein sequence; those that have undergone successful assay development are highlighted. The data are included to show every step of the process from screening up to implementation.