Increased local antitumor effects of interleukin 2 liposomes in mice with MCA-106 sarcoma pulmonary metastases.
The effects of liposome formulations of interleukin 2 (IL-2) and local route were studied in C57BL/6 mice with MCA-106 sarcoma pulmonary metastases. IL-2 liposomes made by hydration of powdered dimyristoyl-phosphatidylcholine with aqueous recombinant IL-2 had 95% of the IL-2 associated with the lipid fraction. When mice with pulmonary micrometastases were treated once daily with free cytokine on days 5, 6, and 7 after tumor inoculation, the intrathoracic route was superior to the i.p. or s.c. routes. When IL-2 liposomes were administered by the local intrathoracic route, significantly better antitumor effects (P less than 0.01) were seen compared to empty liposomes or free IL-2 as determined by (a) increased survival and (b) reduced numbers of pulmonary metastases. Minimal toxicity was observed. Results indicate that local route and incorporation of IL-2 in liposomes may enhance therapeutic efficacy and facilitate more practical daily dosing regimens.
Anderson
P M
PM
Department of Pediatrics, University of Minnesota, Minneapolis 55455.
Katsanis
E
E
Leonard
A S
AS
Schow
D
D
Loeffler
C M
CM
Goldstein
M B
MB
Ochoa
A C
AC
D000818:Animals; D004337:Drug Carriers; D007167:Immunotherapy; D007376:Interleukin-2 / Q000008:administration & dosage* / Q000627:therapeutic use; D008081:Liposomes; D008175:Lung Neoplasms / Q000556:secondary* / Q000628:therapy; D051379:Mice; D008810:Mice, Inbred C57BL; D012513:Sarcoma, Experimental / Q000628:therapy*
D004337:Drug Carriers; D007376:Interleukin-2; D008081:Liposomes