Targeting superoxide dismutase to renal proximal tubule cells inhibits nephrotoxicity of cisplatin and increases the survival of cancer-bearing mice

Because cis-diamminedichloroplatinum(II) (cisplatin) which generates reactive oxygen species induces renal dysfunction, administration of a large dose for killing cancer cells is highly limited. We recently synthesized a cationic superoxide dismutase (SOD) (hexamethylenediamine-conjugated SOD, AH-SOD) which rapidly accumulates in renal proximal tubule cells and inhibits oxidative injury of the kidney. Treatment of Ehrlich ascites tumor cells (EATC)-bearing mice with cisplatin sufficient for killing tumor cells increased their motality. The motality of cisplatin-treated EATC-bearing mice was markedly decreased by AH-SOD. These results suggest that targeting SOD to renal proximal tubule cells might permit the administration of high doses of cisplatin and related anticancer agents without causing renal injury.