Vulnerability of feline T-lymphocytes to charged particles.
An analysis of ionizing radiation-induced damage in peripheral lymphocytes has been employed to predict the prognosis of radiotherapy in terms of toxicity in normal tissues. Therefore, understanding the sensitivity of lymphocytes to high linear energy transfer (LET)-charged particles would be indispensable for utilizing charged particle therapy in veterinary medicine. However, the availability of such information is very limited. This study aimed to compare the radiosensitivity of feline T lymphocytes to gamma-rays (0.2 keV/microm) and 4 different types of charged particles with LET values ranging from 2.8 to 114 keV/microm. It was observed that the relative biological effectiveness, inactivation cross-section, and isodose-induced apoptosis increased in an LET-dependent manner. On the other hand, no difference in apoptosis frequency was observed in the cells exposed to an isosurvival dose of all the radiation types tested. This is the first study that demonstrates the LET dependence of cell killing and apoptosis induction in feline T lymphocytes. Our results suggest that lymphocytes can be effectively used to predict the prognosis of charged-particle therapy in cat patients.
Kakizaki
Takehiko
T
Department of Veterinary Medicine, Kitasato University Graduate School of Veterinary Medicine and Animal Sciences, Towada, Aomori, Japan.
Hamada
Nobuyuki
N
Sakashita
Tetsuya
T
Wada
Seiichi
S
Hara
Takamitsu
T
Funayama
Tomoo
T
Hohdatsu
Tsutomu
T
Natsuhori
Masahiro
M
Sano
Tadashi
T
Kobayashi
Yasuhiko
Y
Ito
Nobuhiko
N
D000818:Animals; D017209:Apoptosis; D002244:Carbon / Q000494:pharmacology*; D002415:Cats; D002478:Cells, Cultured; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D020450:Heavy Ions / Q000009:adverse effects*; D013601:T-Lymphocytes / Q000528:radiation effects*
D002244:Carbon