Abstract B55: Elevation of oxidative expression proteins in colorectal adenomatous polyps

The optimal management of patients with colorectal adenomatous polyps depends on the accuracy of appropriate staging strategies because patients with similar colorectal adenocarcinoma architecture display heterogeneity in the course and outcome of the disease. Chronic oxidative stress may play a critical role in the pathogenesis of colorectal cancers, given that a major promutagenic threat faced by colonic epithelial cells is that of chronic oxidative stress. Although reactive oxygen species arise in most cells as a result of normal metabolic processes, additional sources of oxidative stress in colonic cells may include enzymes such as cyclooxygenase 2 (COX-2) and ATPase 6 and 8. High levels of COX-2 and ATPase protein expression have been detected in human colorectal polyps, which are lesions that can progress to colorectal carcinomas. This study applied spectrophotometric, dinitrophenylhydrazone (DNPH) assay, two dimensional gel electrophoresis, and Western blot analyses to assess the levels of oxidatively modified carbonyl proteins in 37 pairs of normal/surrounding and colorectal adenomatous polyps and cancer tissues. Our data showed that the levels of reactive protein carbonyl groups increased as level of malignancy increased. The level of carbonyl protein was 58% and 26% less in N/S tissues as compare to tumor tissue in adenocarcinoma, and colorectal adenomatous polyps tissues respectably. The differences between the level of carbonyl potion in N/S and tumor tissues was more pronounced in African American patient than in Caucasians. Also the levels of carbonyl proteins were notably higher in tissue contained higher number of tumor cells in different tissues blocks obtained from same patient. Our results may suggest that oxidative stress is involved in oxidatively modification of carbonyl proteins, leading to increased aggressiveness of colorectal polyps. This study was supported by NIGMS grant # GM099663- awarded to Dr. Felix O. Aikhionbare Citation Format: LaShanale M. Wallace, Sharifeh Mehrabi, Shakeria Cohen, Felix O. Aikhionbare. Elevation of oxidative expression proteins in colorectal adenomatous polyps. [abstract]. In: Proceedings of the Seventh AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 9-12, 2014; San Antonio, TX. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2015;24(10 Suppl):Abstract nr B55.