SONODYNAMICALLY INDUCED ANTITUMOR EFFECT OF A GALLIUM-PORPHYRIN COMPLEX, ATX-70

The sonodynamically induced antitumor effect of a gallium-porphyrin co mplex, ATX-70, was evaluated in mice bearing colon 26. In order to fin d the optimum timing for the ultrasonic exposure after the administrat ion of ATX-70, the ATX-70 concentrations in the plasma, skin, and tumo r were measured and analyzed. Antitumor effect was estimated by measur ing the tumor size. When used alone, ultrasound showed a slight antitu mor effect, which became increasingly significant as the dose of ATX-7 0 was increased, while use of ATX-70 alone had no significant effect. At an ATX-70 dose of 2.5 mg/kg or higher, the average tumor size decre ased to smaller than a half by three days after the ultrasonic exposur e. This was smaller than a third of the size of the untreated tumors o n the same day. From these results, it is concluded that ATX-70 signif icantly sensitizes tumors to ultrasound, demonstrating a synergistic a ntitumor effect.