%0 Journal Article %@ 0360-3016 %A Rwigema, JCM %A Beck, B %A Wang, W %A Doemling, A %A Epperly, MW %A Shields, D %A Goff, JP %A Franicola, D %A Dixon, T %A Frantz, MC %A Wipf, P %A Tyurina, Y %A Kagan, VE %A Wang, H %A Greenberger, JS %D 2011 %F pittir:18756 %J International Journal of Radiation Oncology Biology Physics %N 3 %P 860 - 868 %T Two strategies for the development of mitochondrion-targeted small molecule radiation damage mitigators %U http://d-scholarship-dev.library.pitt.edu/18756/ %V 80 %X Purpose: To evaluate the effectiveness of mitigation of acute ionizing radiation damage by mitochondrion-targeted small molecules. Methods and Materials: We evaluated the ability of nitroxide-linked alkene peptide isostere JP4-039, the nitric oxide synthase inhibitor-linked alkene peptide esostere MCF201-89, and the p53/mdm2/mdm4 protein complex inhibitor BEB55 to mitigate radiation effects by clonogenic survival curves with the murine hematopoietic progenitor cell line 32D cl 3 and the human bone marrow stromal (KM101) and pulmonary epithelial (IB3) cell lines. The p53-dependent mechanism of action was tested with p53+/+ and p53-/- murine bone marrow stromal cell lines. C57BL/6 NHsd female mice were injected i.p. with JP4-039, MCF201-89, or BEB55 individually or in combination, after receiving 9.5 Gy total body irradiation (TBI). Results: Each drug, JP4-039, MCF201-89, or BEB55, individually or as a mixture of all three compounds increased the survival of 32D cl 3 (p = 0.0021, p = 0.0011, p = 0.0038, and p = 0.0073, respectively) and IB3 cells (p = 0.0193, p = 0.0452, p = 0.0017, and p = 0.0019, respectively) significantly relative to that of control irradiated cells. KM101 cells were protected by individual drugs (p = 0.0007, p = 0.0235, p = 0.0044, respectively). JP4-039 and MCF201-89 increased irradiation survival of both p53+/+ (p = 0.0396 and p = 0.0071, respectively) and p53 -/- cells (p = 0.0007 and p = 0.0188, respectively), while BEB55 was ineffective with p53-/- cells. Drugs administered individually or as a mixtures of all three after TBI significantly increased mouse survival (p = 0.0234, 0.0009, 0.0052, and 0.0167, respectively). Conclusion: Mitochondrial targeting of small molecule radiation mitigators decreases irradiation-induced cell death in vitro and prolongs survival of lethally irradiated mice. © 2011 Elsevier Inc.