"A major challenge in treating lung tumors with radiation is the toxicity of radiation to healthy tissue," said Joel S. Greenberger, M.D., professor, University of Pittsburgh School of Medicine. "This can result in major quality-of-life issues for lung cancer patients receiving radiation therapy for their diseases. In previous studies, we demonstrated that gene therapy may protect healthy tissues from damage prior to an initial course of radiation therapy. In this study, we found that gene therapy also can protect the same healthy tissue during retreatment with radiation." Dr. Greenberger explained that a related study shows the effectiveness of aerosol delivery of this therapy by an inhalation nebulizer making it clinically feasible.
In the study, animal models were used to test the protective effects of manganese superoxide dismutase plasmid liposome (MnSOD-PL) gene therapy during exposure to radiation. One group of mice received an intratracheal injection of MnSOD-PL 24 hours before a course of 14 Gy irradiation, while a second group received 14 Gy irradiation alone. The mice were observed for six months for any toxic pulmonary effects and then subdivided into two more groups. One of these groups was exposed to a second lung irradiation of 10 Gy without MnSOD-PL and the other received an injection of MnSOD-PL 24 hours prior to radiation exposure.
The researchers found that in mice that received the initial 14 Gy dose there was 50 percent survival at 180 days (due to lung toxicity) compared to 87.5 percent survival during the same length of
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16-Oct-2005