[Biomarker development by cancer proteomics]

Cancer is a genetically and clinically diverse disease, and biomarkers are required to optimize the therapeutic strategies. Proteome is a functional translation of genome, directly regulating cancer phenotypes. Biomarker studies have been conducted by the proteomic approach. By the proteomic approach, we developed a novel prognostic biomarker in gastrointestinal stromal tumor(GIST). In GIST, adjuvant imatinib mesylate after resection improved recurrence-free survival. A prognostic biomarker is required to select the patients for the treatment with imatinib mesylate. Proteomic approach using two-dimensional difference gel electrophoresis(2D-DIGE) identified pfetin as a biomarker for favorable prognosis. Multi-institutional validation study by immunohistochemistry established the prognostic values of pfetin in GIST. Pfetin will be applicable for a novel prognostic modality.