2007 Outstanding Career Achievement: Edouard Alexandre Azzam, PhD

Edouard Azzam earned his Ph.D. degree in Radiation Biology from the University of Ottawa (Canada) in 1995. During his post-graduate studies and subsequent research career, he focused on characterizing the effects of low dose/low fluence ionizing radiation in normal human cells. He has shown that biological effects at low doses cannot be predicted from effects at high doses. He extended earlier studies in human lymphocytes and found that adaptive responses to g-radiation also exist in human and rodent fibroblasts. Pre-exposure to small doses of g-rays protected against DNA damage and carcinogenesis from subsequent exposures to higher doses of radiation. In particular, under the mentorship of Professor Ron Mitchel, he found that exposure of mouse embryo cells to doses as low as 1 mGy reduced the level of chromosomal damage due to endogenous oxidative processes and decreased the frequency of neoplastic transformation to a level below the spontaneous rate. More recently, at his laboratory at the New Jersey Medical School where he is Associate Professor, he showed that low dose/low dose-rate g-ray exposures modulate cell cycle progression, and up-regulate anti-oxidant defenses and DNA repair activity in normal human fibroblasts grown under conditions encountered in vivo. While mitochondrial protein import and membrane potential were decreased by high dose g-radiation, they were enhanced by low doses. His ongoing studies have also revealed novel biomarkers of low dose exposures that are associated with cytoprotective properties. In addition, Edouard is pursuing research on propagation of radiation effects (i.e. the bystander response) that he began during his post-doctoral studies at Harvard University under the mentorship of Professor John Little. His data indicate that cytoprotective effects induced by low dose g-rays may be propagated to neighboring cells by intercellular communication mechanisms. Currently, his research is supported by the US Department of Energy, NIH, and NASA.