PT - JOURNAL ARTICLE AU - Jeffrey M. Dick TI - Proteomic indicators of oxidation and hydration state in colorectal cancer AID - 10.1101/035857 DP - 2016 Jan 01 TA - bioRxiv PG - 035857 4099 - http://biorxiv.org/content/early/2016/01/04/035857.short 4100 - http://biorxiv.org/content/early/2016/01/04/035857.full AB - New integrative approaches are needed to harness the potential of rapidly growing data sets of gene and protein expression and microbial taxonomic identification in colorectal cancer (CRC). Using reported data from human proteomic and microbial taxonomic studies, this study compares the average oxidation state of carbon (ZC) and water demand per residue of proteins from tumors to those in healthy tissues or less advanced cancer stages. The major compositional trends are lower ZC and, to a lesser extent, higher , in tumor vs normal groups, or carcinoma vs adenoma groups. Comparison of microbial protein compositions shows a small shift toward lower ZC in bacteria enriched in fecal samples from cancer patients. Thermodynamic calculations of the relative chemical stabilities of proteins show that the cancer-related proteins tend to be stabilized by higher chemical activity of H2O (more hydrating) and/or lower fugacity of O2 (more reducing). The compositional exploration of molecular data suggests that a systematic chemical transformation is a central aspect of the cancer proteome. The thermodynamic calculations highlight the potential for interpreting proteomic data within a biochemical context, and may contribute to a better understanding of the microenvironmental requirements for cancer initiation and progression.