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Updated: Jul 10, 2026
A Bioluminescent and Fluorescent Orthotopic Syngeneic Murine Model of Androgen-dependent and Castration-resistant Prostate Cancer
Published on: March 6, 2018
Radiation and a metalloporphyrin radioprotectant in a mouse prostate tumor model
Daila S Gridley1, Adeola Y Makinde, Xian Luo
1Departments of Radiation Medicine, Loma Linda University and Medical Center, Loma Linda, CA 92354, USA. dgridley@dominion.llumc.edu
Background:
Antioxidants have the potential to protect normal tissues against radiation-induced damage, but must not protect tumor cells during radiotherapy. The major objectives were to determine whether a metalloporphyrin antioxidant affects prostate tumor response to radiation and identify possible mechanisms of interaction.
Materials And Methods:
C57BL/6 mice with RM-9 tumor were treated with manganese (III) meso-tetrakis (1,3-diethylimidazolium-2-yl) porphyrin (MnTDE-2-ImP) and 10 gray (Gy) radiation. Tumor volume was quantified and a subset/group was evaluated for hypoxia-inducible factor-1alpha (HIF-1alpha), bone marrow-derived cell populations and cytokines.
Results:
The addition of MnTDE-2-ImP transiently increased tumor response compared to radiation alone. The group receiving drug plus radiation had reduced intratumoral HIF-1alpha and decreased capacity to secrete TNF-alpha, whereas production of IL-4 was increased. There were no toxicities associated with combination treatment.
Conclusion:
The results demonstrate that MnTDE-2-ImP did not protect the RM-9 prostate tumor against radiation; instead, radiation effectiveness was modestly increased. Possible mechanisms include reduction of radiation-induced HIF-1alpha and an altered cytokine profile.
