OBJECTIVETo assess the antitumor efficacy and adverse effects of bortezomib either used alone or in combination with arsenic trioxide for transplanted tumor in nude mice.

METHODSNude mice bearing HL-60 cell xenografts were randomized into 4 groups to receive treatment with normal saline, bortezomib, arsenic trioxide, bortezomib plus arsenic trioxide. The tumor growth inhibition and general condition of the nude mice were observed, and in situ TUNEL assay and immunohistochemistry were performed on the transplanted tumors.

RESULTSBortezomib alone and in combination with arsenic trioxide could both inhibit the growth of the transplanted tumors, prolong the survival of the nude mice, and induce cell apoptosis and growth inhibition of the HL-60 cells in vivo, and the combined administration exhibited even better effects. The administration was well tolerated with causing manifest vital organ damages in the mice.

CONCLUSIONBortezomib in combination with arsenic trioxide has significant antitumor effect in nude mice bearing HL-60 cell xenografts possibly by inducing HL-60 cell apoptosis and growth inhibition without producing no significant adverse effects.