An association between oxidative stress and radiation-induced lymphomagenesis.
It is generally thought that reactive oxygen species (ROS) play an important role in carcinogenesis. However, direct evidence supporting this idea is still lacking. In the present study, we measured ROS in thymocytes at the thymic prelymphoma stage in C57BL/6 mice. Mice (n = 20) were irradiated at 1.6 Gy/week for 4 consecutive weeks and the levels of ROS were measured 8 to 11 weeks later by dehydrorhodamine 123, which accumulated in mitochondria and became fluorescent dye upon oxidation. Unirradiated littermates (n = 17) served as controls. Thymic prelymphoma cells were diagnosed by the aberrant CD4/CD8 staining profile and monoclonal or oligoclonal T-cell receptor gene rearrangement. A significant fraction of mice (11/13) bearing thymic prelymphoma cells exhibited elevated levels of ROS in thymocytes (P < 0.001). The result is consistent with the hypothesis that ROS may play an important role in radiation carcinogenesis.
Suzuki
Gen
G
Department of Clinical Studies, Radiation Effects Research Foundation, Hiroshima, Japan. gsuzuki@rerf.or.jp
Shimada
Yoshiya
Y
Hayashi
Tomonori
T
Akashi
Makoto
M
Hirama
Toshiyasu
T
Kusunoki
Yoichiro
Y
D000818:Animals; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000528:radiation effects*; D008223:Lymphoma / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D009381:Neoplasms, Radiation-Induced / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress / Q000528:radiation effects*; D011829:Radiation Dosage; D011836:Radiation Tolerance; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012016:Reference Values; D013223:Statistics as Topic; D013953:Thymus Neoplasms / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured / Q000378:metabolism / Q000528:radiation effects; D014916:Whole-Body Irradiation
D017382:Reactive Oxygen Species