[Intratumoral injection of biological response modifier (BRM)]

Specific antitumor effects of lymphokine activated lymphocytes obtained from tumor-bearing mice after intratumoral injection of IL-2 were studied. Furthermore, effects of preoperative endoscopic intratumoral injection combined IL-2 and Lentinan or OK-432 were clinically studied against gastric cancer. The results were as follows: After intratumoral consecutive injection of recombinant human IL-2 (rhIL-2), the splenocytes of these mice were cultured with rhIL-2 and the effector cells were obtained. 1) Adoptive transfer of the effector cells specifically diminished the size of the host tumor and prolonged the life span of the mice. 2) The analysis of the surface antigens indicated the Thy1.2, Thy1.2+ L3T4+ cells increased in the effector cells as the specific cytotoxicity of them were augmented. 3) Preoperative endoscopic intratumoral injection combined IL-2 and Lentinan or OK-432 induced immunocytes including antigen-presenting cells in the site of the gastric cancer, and increased the IL-2R and the LAK activity of PBL. This method was considered as effective as an adjuvant treatment of gastric cancer surgery as a in vivo sensitization.