PARENT SESSION
1:30 PM to 3:30 PM
Tuesday, April 23, 2002
Poster Session 17 Induced Gene Expression
Room: Nevada Exhibition Center
(P22-229) Detection of gene targets in irradiated MCF-7 cells.
Abend, Michael*,1, Staßen, Tanja1, Frombeck, Sabina1, 1 Institute of Radiobiology, Federal Armed Forces Medical Academy, Neuherbergstr. 11, Munich, Germany
ABSTRACT-
Gene targets applicable for biological dosimetry were examined in MCF-7 (human mammary carcinoma) cells exposed to 2 and 6 Gy X-rays. Expression of 1176 genes was traced with AtlasTM Human 1.2. Array (Clontech). (1) Based on data reproducibility (> 90 %) a new and improved analysis was employed. (2) Normalization of data using Ubiquitin or total gene expression led to the same results. (3) A dose dependent gene expression was shown for seven genes which were constantly expressed over 1 day (4 genes) and 2 days (3 genes). Four out of the seven genes represent novel radiation induced gene targets. (4) When analyzing expression of all genes, processes of cell degradation (e.g. cell death and protein catabolism) were activated. Simultaneously, an inhibition not only of cell proliferation, but also of other cellular functions (e.g. cell repair) was found. Hence, cell death appears as a process of "active silencing". In conclusion, screening for appropriate gene targets can be performed sucessfully with the gene expression array. It remains to be shown that the seven selected genes can be used for biological dosimetry in other cell models and whether "active silencing" represents a general principal of radiation induced cell death.
KEYWORDS: gene targets, biological dosimetry, irradiation