Lung metastasis suppression of the bifunctional new radiosensitizer KIN-806.

KIN-806 is one of the newly developed 2-nitroimidazole derivative hypoxic cell radiosensitizers. The tumor growth control and the suppression of lung metastasis induced by KIN-806 were evaluated. Female C3H/He mice and SCCVII tumor cells were used. 30 Gy or 40 Gy was delivered as local irradiation. 0.2 g/kg or 0.4 g/kg KIN-806 was administered 30 min before this treatment to the KIN-806 administered groups. The enhancement ratio of KIN-806 evaluated using the growth delay method was 1.8. KIN-806 showed an excellent effect as a radiosensitizer. Furthermore, KIN-806 suppressed lung metastasis regardless of radiation, and the control of the metastatic lung nodules did not depend on the irradiation dose but rather on the KIN-806 dose (0.2 g/kg < 0.4 g/kg). KIN-806 is a promising bifunctional radiosensitizer which promotes anti-tumor activity in addition to having a radiosensitizing effect.