Inhibition of growth of rat hepatoma by local injection of liposomes containing recombinant interleukin-2. Antitumor effect of IL-2 liposome.

Human recombinant interleukin-2 (IL-2) was entrapped in liposome, consisting of egg phosphatidylcholine (PC) and cholesterol. The peri-tumor injections of IL-2 liposome inhibited significantly the growth of solid tumor and prolonged the survival time of rats with solid tumors which were induced by a subcutaneous (s.c.) inoculation of AH-66 cells. Immunohistochemical staining of peritoneal exudate cells and tumor tissues revealed a marked accumulation of activated macrophages in and around the tumor tissues induced by the local injections of IL-2 liposome.