PARENT SESSION
1:30 PM to 3:30 PM
Wednesday, April 24, 2002
Poster Session 26 Apoptosis
Room: Nevada Exhibition Center
(P31-305) Discovery of novel radiation-induced proteins by protein microarray.
Nyati, Mukesh*,1, Sreekumar, Arun2, Varambally, Sooryanarayana2, Barrette, Terrence2, Ghosh, Debashis3, Chinnaiyan, Arul2, Lawrence, Theodore1, 1 Department of Radiation Oncology, Ann Arbor, MI2 Departments of Pathology, Ann Arbor, MI3 Department of Biostatistics, Ann Arbor, MI
ABSTRACT-
Radiation-induced apoptosis results from a complex series of protein activations that may be difficult to reconstruct without a global knowledge of changes. The advent of DNA microarray is likely to have a major impact on the understanding of the complexities involved in this process. However, obtaining a global perspective of proteins involved in radiation response is still more challenging. We have developed a microarray-based platform that can be used to measure protein levels and activities in a complex biological milieu of the cell lysate (Cancer Research 61, 7585-7593, 2001). We wished to compare the protein pattern of irradiated and control LoVo cells, which is a colon cancer cell line highly prone to apoptosis. Using such a protein microarray made up of 1920 elements (146 distinct antibodies) we were able to observe alterations at protein levels in LoVo colon carcinoma cells upon irradiation such as p53, DFF40, DFF45, TRAIL, DR5, DcR2, FLIP, UCP2 and RICK among others. Interestingly, we also observed radiation-induced down-regulation of carcinoembryonic antigen (CEA), a prototypic cancer biomarker. Protein microarray information was validated by immunoblotting. These findings demonstrate that multiple pro apoptotic proteins are induced by radiation, suggesting that a full understanding of the molecular events will require simultaneous assessment of multiple proteins. The role of selected proteins like UCP2, RICK and CEA, in response to radiation treatment are under investigation.
KEYWORDS: Radiation , Protein Microarray, CEA, UCP2