Identification of chemosensitivity markers for postoperative adjuvant chemotherapy using cellular, molecular, and immunohistochemical profiles of advanced carcinomas from gastrointestinal tract.

55 Background: The prediction of chemotherapeutic efficacy is a fundamental problem. We have developed an effective system to identify prediction markers based on an in vitro approach using a quantitative matrix of chemosensitivity assay (CSA) and protein expression by reverse-phase protein lysate microarrays (RPA), followed by tissue microarrays (TMA). In the present study, we attempted to identify predictive markers by extracting candidate proteins from the “chemosensitivity x protein expression matrix” of 12 cancer cell lines and 12 chemotherapeutic agents, followed by examination using TMA in post-operative adjuvant chemotherapy for advanced gastric and colorectal carcinomas. Methods: The “chemosensitivity x protein expression matrix” was constructed using quantitative data from CSA and RPA. TMA was constructed from parafin-embedded, formalin-fixed surgically removed tissues from 30 gastric and 49 colorectal carcinomas. All subjects had received post-operative adjuvant chemotherapy. Expression and/or ...