We investigated the effect of exogenous wild type p53 on the radiation induced cells apoptosis and necrosis at different levels of linear energy transfer (LET) to evaluate its mechanisms. The human melanoma cell line A375,which bore wild-type p53 gene status was used, as well as the transfectant A375 cells (A375/p53) with adenoviral vector containing the wild-type p53 gene. We exposed these cells to X-rays and to accelerated carbon-ion(C-) beams. Carbon ions were accelerated by a heavy-ion accelerator at Insti- We investigated the effect of exogenous wild type p53 on the radiation induced cells apoptosis and necrosis at different levels of linear energy transfer (LET) to evaluate its mechanisms. The human melanoma cell line A375, which bore wild-type p53 gene status was used, As well as the transfectant A375 cells (A375 / p53) with adenoviral vector containing the wild-type p53 gene. We exposed these cells to X-rays and to accelerated carbon-ion (C-) beams. -ion ​​accelerator at Insti-