Proteomic approaches in colon cancer: promising tools for new cancer markers and drug target discovery.

Novel technologies are needed from which to identify new and more efficient biomarkers and improved molecular targets for the expedient and accurate diagnosis and treatment of colorectal cancer. Many advances have been made in direct and virtual imaging for detection of polyps and malignant-type lesions. These require tissue verification before definitive intervention. Inclusion of a simple serum test, more accurate than CEA, especially for early cancer detection, would make virtual imaging much more successful. Proteomics, the study of the proteins and protein pathways involved in disease, is a new dimension in preclinical and clinical development. Mass spectrometric analysis of serum proteins has been shown to be a fast and simple approach yielding a large datastream of information to mine for biomarker patterns. Preliminary studies in a variety of cancers has shown this to be a promising direction. Protein arrays of tumor lysates allows assessment of expression and activation of proteins that may be specific colorectal cancer targets or targets that are shown to be universally important in cancer, such as those proteins involved in angiogenesis. Small quantities of tumor are needed for this technique and allow direct analysis of the biochemical events ongoing in the tumor and/or the stroma. This provides insight into the biology of the disease and can be used to identify targets for therapeutic intervention as well as to monitor the ability to successfully attack those targets. Together, these 2 technologies have been shown to advance the field and may be important new steps in diagnosis, prognosis, and treatment of colorectal cancer.