OBJECTIVETo investigate the effect of deferoxamine (DFO) and DFO in combination with arsenic trioxide (ATO) on inhibition of HL-60 cells xenograft tumor growth in nude mice and its mechanism.

METHODSXenograft tumor model of HL-60 cell line in nude mice was established by inoculating HL-60 cells subcutaneously into nude mice. The tumor-bearing mice were randomly divided into four groups: 50 mg/kg DFO group (group I), 3 mg/kg ATO group (group II), combination group (50 mg/kg DFO + 1.5 mg/kg ATO (group III) and normal saline control group. The drugs were administered intraperitoneally from the day of inoculation (once a day for 10 days). The inhibitory effects on the tumor growth were compared. NF-κBp65 expression levels of the tumors were detected by immunohistochemistry (24h after the last administration).

RESULTS(1) Tumors growth could be observed in all of the nude mice on day 7 to day 8 after inoculation, 0.5 - 1.0 cm in diameter, and then grew rapidly; (2) Tumor weight of control group, group I, group II and group III were (2.62 ± 0.54) g, (2.55 ± 0.82) g, (2.34 ± 0.79) g and (1.95 ± 0.39) g respectively, and the growth inhibition rates in group I, group II and group III were 2.67%, 10.69% and 25.57% respectively. Both DFO alone and in combination with ATO could inhibit the growth of transplanted tumors, and the combination group exhibited more effects, with no vital organ damages in the tumor-bearing mice. (3) There was significant difference in mean value of NF-κBp65 expression among the three experimental groups (P < 0.05), with a descending order of control group > group II, > group I > group III.

CONCLUSION(1) Both DFO and ATO have antitumor activities on tumor-bearing mice, and their combination has an obvious and significant effect. (2) DFO combined with ATO, is well tolerated with no significant adverse effects in the nude mice. (3) Both DFO and ATO can downregulate NF-κBp65 expression of transplanted tumors, especially for their combination.