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Radiology Research and Practice
Volume 2011, Article ID 679806, 9 pages
http://dx.doi.org/10.1155/2011/679806
Research Article

Differential Effects of Alpha-Particle Radiation and X-Irradiation on Genes Associated with Apoptosis

Consumer and Clinical Radiation Protection Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, 775 Brookfield Road, PL 6303B, Ottawa, ON, Canada K1A 0K9

Received 15 March 2011; Accepted 5 April 2011

Academic Editor: Felix Diekmann

Copyright © 2011 Vinita Chauhan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This study examined differential effects of alpha-(α-) particle radiation and X-rays on apoptosis and associated changes in gene expression. Human monocytic cells were exposed to α-particle radiation and X-rays from 0 to 1.5 Gy. Four days postexposure, cell death was measured by flow cytometry and 84 genes related to apoptosis were analyzed using real-time PCR. On average, 33% of the cells were apoptotic at 1.5 Gy of α-particle radiation. Transcript profiling showed statistical expression of 15 genes at all three doses tested. Cells exposed to X-rays were <5% apoptotic at ~1.5 Gy and induced less than a 2-fold expression in 6 apoptotic genes at the higher doses of radiation. Among these 6 genes, Fas and TNF-α were common to the α-irradiated cells. This data suggests that α-particle radiation initiates cell death by TNF-α and Fas activation and through intermediate signalling mediators that are distinct from X-irradiated cells.