Immunotherapy against cancer includes induction of Th1-type immune responses by the inducer of IL-12 as well as administration of Th1-type cytokines such as IFN-γ. Both are aimed to enhance Th1-type immune responses, leading to the activation of NK cells and cytotoxic T cells, which eliminate cancer cells. HK L-137 enhances Th1-type immune responses by inducing the production of IL-12 and IFN-γ, and therefore is expected to exert an anticancer effect.
HK L-137 was administered to the mice transplanted with cancer cells, and the survival period of the mice was examined. Improvement of the survival rate and prolongation of the survival period were observed in the mice administered HK L-137, demonstrating an anticancer effect of HK L-137.
The cancer cells were transplanted into the peritoneal cavity of the mice, and their survival was observed.
In the test group, 0.5 mg of HK L-137 was intraperitoneally administered for 5 consecutive days from the Day 7 after transplantation of the cancer cells.
Cancer expansion due to cancer cell growth resulted in an increase in the body weight, however, the increase in the body weight was suppressed in the HK L-137 group, compared to the control group. All the mice in the control group died within 23 days after the transplantation, but no deaths were observed in the HK L-137 group during the same period. Some mice died after Day 23, however, 40% had survived until the end of the study.
Cancer cells generally possess the ability to suppress immune functions, and this is one of the strategies of cancer cells to avoid being attacked by immune cells.
HK L-137 promotes IL-12 production and induces Th1-type immune responses. HK L-137 improved the survival rate and prolonged the survival period possibly due to the activation of suppressed Th1-type immune responses which can promote the elimination of cancer cells.
Reference: Cancer Immunol Immunother 49: 157-164, 2000