Heavy-ion induced bystander effects between different type cells

Ikeda, Hiroko; Yokota, Yuichiro; Funayama, Tomoo; Kobayashi, Yasuhiko; Kanai, Tatsuaki*

In this study, we used human lung normal fibroblast cell line WI-38, and human lung cancer cell line H1299/wtp53. To detect only the medium-mediated bystander effects, we adopted cell co-culture systems. The result indicated that the clonogenic abilities of the non-irradiated cells were increased when the cells irradiated with carbon ions transmitted bystander signals via medium to the different type of the cells. In contrast, the clonogenic abilities were decreased when irradiated cells were co-cultured with the same type of non-irradiated cells. From the result, it is suggested that there is a large difference in heavy-ion induced bystander responses via medium between the same type cells and different type cells. Now, we start the establishment of experimental systems for irradiating a part of confluent cells of mixed culture in the same dish using microbeam.