The Survival of heavy ion-irradiated Bcl-2 overexpressing radioresistant tumor cells and their progeny

Hamada, Nobuyuki*; Hara, Takamitsu*; Omura, Motoko*; Funayama, Tomoo; Sakashita, Tetsuya; Sora, Sakura*; Nakano, Takashi*; Kobayashi, Yasuhiko

Here, we investigated the cell killing effectiveness of heavy-ion radiation in Bcl-2 overexpressing radioresistant tumor cells. First, irradiated cells underwent primary colony formation. Radioresistance decreased with increasing linear energy transfer (LET), indicating that heavy ions may be a promising therapeutic modality for Bcl-2 overexpressing tumors. Second, cells in primary colonies were reseeded for secondary colony formation. The incidence of delayed reproductive death increased with LET irrespective of Bcl-2 overexpression, suggesting that Bcl-2 overexpression may not facilitate heavy ion induced genomic instability.