¹Department of Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA

Correspondence: Dr JS Greenberger, Department of Radiation Oncology, University of Pittsburgh Medical Center, 200 Lothrop Street, Pittsburgh, PA 15213-2532, USA. E-mail: greenbergerjs@upmc.edu

Received 6 March 2007; Revised 25 May 2007; Accepted 1 July 2007; Published online 16 August 2007.

Abstract

Cytotoxic exposure of bone marrow and other non-hematopoietic organs containing self-renewing stem cell populations is associated with damage to the supportive microenvironment. Recent evidence indicates that radical oxygen species resulting from the initial oxidative stress persist for months after ionizing irradiation exposure of tissues including oral cavity, esophagus, lung and bone marrow. Antioxidant gene therapy using manganese superoxide dismutase plasmid liposomes has provided organ-specific radiation protection associated with delay or prevention of acute and late toxicity. Recent evidence has suggested that manganese superoxide dismutase transgene expression in cells of the organ microenvironment contributes significantly to the mechanism of protection. Incorporating this knowledge into designs of novel approaches for stem cell protection is addressed in the present review.