Augmentation of antitumor effect on syngeneic murine solid tumors by an interleukin 2 slow delivery system, the IL-2 mini-pellet

Toshiyoshi Fujiwara, Kenichi Sakagami, Junji Matsuoka, Shigehiro Shiozaki, Keiji Fujioka, Yoshihiro Takada, Susumu Uchida, Tadashi Onoda, Kunzo Orita

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


We evaluated the antitumor effect of an interleukin 2 (IL-2) slow delivery system, the IL-2 mini-pellet, in two murine solid tumor models, and also investigated the enhancement of its therapeutic effect by serial administration. The IL-2 mini-pellet contains 1 × 106 units of IL-2 and releases it slowly in vivo. In our experiment, the IL-2 mini-pellet was administered subcutaneously near the tumor site in combination with the intravenous injection of lymphokine-activated killer (LAK) cells. When this regimen was given on days 8 and 11 after the subcutaneous inoculation of Meth A fibrosarcoma into BALB/c mice, tumor growth was significantly inhibited (p < 0.05) compared to tumor growth in untreated controls. Moreover, the IL-2 mini-pellet alone was also effective in inhibiting tumor growth. In another experiment, MH134 hepatoma was inoculated into C3H/He mice. Both administration of the IL-2 minipellet alone and in combination with LAK cells resulted in complete tumor regression in four of five mice. In a third experiment, serial administration of the IL-2 mini-pellet at 3- or 5-day intervals prolonged the suppression of Meth A fibrosarcoma growth in BALB/c mice. These results suggested that the IL-2 mini-pellet could be applied to cancer immunotherapy and that its antitumor effect could be prolonged by serial administration.

Original languageEnglish
Pages (from-to)203-209
Number of pages7
Issue number3
Publication statusPublished - Jul 1 1991


  • MH134 hepatoma
  • Meth A fibrosarcoma
  • drug delivery system
  • interleukin 2
  • lymphokine-activated killer cells

ASJC Scopus subject areas

  • Pharmacology


Dive into the research topics of 'Augmentation of antitumor effect on syngeneic murine solid tumors by an interleukin 2 slow delivery system, the IL-2 mini-pellet'. Together they form a unique fingerprint.

Cite this