Epperly, M. W., Epperly, L. D., Niu, Y., Wang, H., Zhang, X., Franicola, D. and Greenberger, J. S. Overexpression of the MnSOD Transgene Product Protects Cryopreserved Bone Marrow Hematopoietic Progenitor Cells from Ionizing Radiation. Radiat Res. 168, 560–566 (2007).

We determined whether manganese superoxide dismutase (MnSOD)-plasmid liposome (PL) transfection of C57BL/ 6NHsd mouse bone marrow protected cells irradiated at room temperature (24°C) or in the cryopreserved state. MnSOD-overexpressing hematopoietic progenitor 2C6 cells were radioresistant compared to the parent 32D cl 3 cells when irradiated frozen or at 24°C. Fresh whole marrow from mice injected intravenously with MnSOD-PL prior to explant as well as explanted marrow single cell suspensions transfected in vitro were irradiated at 24°C or −80°C. In vivo or in vitro transfection of marrow with MnSOD-PL produced significant radiation protection of irradiated marrow progenitor cells compared to controls at 24°C or −80°C. (in vivo transfection D₀ 2.19 ± 0.21 at 24°C, D₀ 2.10 ± 0.07 at −80°C compared to control D₀ 1.56 ± 0.06 or 1.66 ± 0.04, P = 0.047 and 0.017 respectively; in vitro transfection D₀ 2.35 ± 0.11 at 24°C, D₀ 3.42 ± 0.13 at −80°C compared to D₀ 1.81 ± 0.01 or 2.53 ± 0.05, P = 0.0087 and 0.0026, respectively). Thus the MnSOD transgene product protects frozen marrow cells as well as marrow cells irradiated at 24°C.