Remission of L540Cy Hodgkin tumors in a NOD/SCID mouse model after treatment with As2O3. (A) L540Cy cells were treated for 8 hours with the indicated concentrations of As2O3. Whole cell lysates were analyzed for NF-κB DNA binding activity by EMSA. Free DNA probe is not shown; ns indicates nonspecific. (B) L540Cy tumor cells were xenotransplanted in NOD/SCID mice. Mice with palpable tumors were treated for 15 days with PBS (⋄, control; n =6) or 3.75 mg/kg As2O3(▪, n =6) intravenously daily and thereafter for another 8 days with 7.5 mg/kg/d. The tumor volume is indicated. (C-D) Palpable L540Cy (C) or HD-MyZ (D) tumors in NOD/SCID mice were treated with either PBS (⋄, n =6) or 5 (▪, n =6) and 7.5 (▴, n =6) mg/kg/d As2O3intravenously, beginning on day 8 after transplantation. Right panels: modulation of NF-κB activity in L540Cy and HD-MyZ tumor cells in vivo. Animals of the control group were treated on day 24 (L540Cy) or day 18 (HD-MyZ) with PBS alone or with 7.5 mg/kg As2O3intravenously. Tumors were explanted 6 hours after As2O3application. Whole cell extracts of the tumor material were analyzed by EMSA for NF-κB DNA binding activity. Free DNA probe is not shown; ns indicates nonspecific.
