The synergistic antitumor effect of recombinant interleukin-1 and low-dose of cyclophosphamide in tumor-bearing mice.
Intraperitoneal (i.p.) treatment of MOPC104E ascitic tumor-bearing BALB/c mice with interleukin-1 (IL-1) followed by a low dose of cyclophosphamide (CPA) resulted in synergistic prolongation of their survival time. This antitumor effect was abolished when administration of CPA preceded that of IL-1. The combined i.p. therapy also eradicated subcutaneous (s.c.) tumors, indicating a systemically operating antitumor mechanism. In Winn assay, splenocytes from MOPC104E-bearing mice treated with the combined therapy completely suppressed the growth of MOPC104E cells, but not that of another syngeneic tumor cell line, RL female-8 cells. This tumor-neutralizing activity was completely abrogated by treatment with anti-asialo-GM1 or anti-Thy1.2 and complement, and reduced by treatment with anti-Lyt2.2 and complement. Treatment of splenocytes with 1-leucine methyl ester (Leu0Me), which depletes natural killer (NK) cells and macrophages in vitro, did not affect the neutralizing activity.
Harada
T
T
First Department of Surgery, Faculty of Medicine, Kyoto University, Japan.
Kan
N
N
Ichinose
Y
Y
Moriguchi
Y
Y
Li
L
L
Sugie
T
T
Okino
T
T
Imamura
M
M
D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D003520:Cyclophosphamide / Q000008:administration & dosage; D004357:Drug Synergism; D005260:Female; D007375:Interleukin-1 / Q000008:administration & dosage; D007942:Leukemia, Experimental / Q000188:drug therapy*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010954:Plasmacytoma / Q000188:drug therapy*; D011994:Recombinant Proteins / Q000008:administration & dosage; D014407:Tumor Cells, Cultured
D007375:Interleukin-1; D011994:Recombinant Proteins; D003520:Cyclophosphamide