Human natural killer (NK) cells are major players in innate immune response. The functions of these cells as a scavenger of cancer cells are enhanced by cytokines such as interleukin-2 (IL-2), which play an important role in immune response in both tumors and virally infected cells. Liver cancer has a high incidence rate and is a major cause of death in Korea. We provide evidence that human NK cells inhibit tumor growth of the hepatocellular carcinoma cell line SNU-354. NK cells were cultured with human IL-2 for 14 days, yielding an enriched NK cell population containing 35% CD8+ cells, 6% CD4+ cells, and 51% CD16+ /CD56+ cells. Intravenous injection of NK cells at doses from 2.5 to 10 million cells/mouse was administered once per week in a nude mouse model that retains human liver tumor induced by implantation of SNU-354 cells. The results showed that human NK cells were recruited within tumor tissue and inhibited SNU-354 tumor growth by 32%, 58%, and 65%. The current data suggest the potential for use of NK cell-based immunotherapy for treatment of human liver cancer.

The purpose of this study was to evaluate the inhibitory effect of commercial Makgeolli on tumor growth in human gastric adenocarcinoma cells (AGS) in a xenograft cancer model, transplanted with AGS cells. Commercial Makgeolli was first dealcoholized by evaporation and used as the test sample. We detected a significant increase in the volume and weight of tumor in nude mice (induction) that were transplanted with AGS cells. Administration of 100 mg/kg·day group (ML), and 500 mg/kg·day group (MH) dealcoholized commercial Makgeolli significantly decreased tumor growth. In this study, 5-FU 18 mg/kg·day was used as a positive control for tumor growth inhibition. Additionally, determination of the body weight of both the groups revealed no side effects after the administration of dealcoholized commercial Makgeolli. Using the cell culture system, we also evaluated the effect of dealcoholized commercial Makgeolli on caspase-3/7 activity in the AGS cells. Treatment with dealcoholized commercial Makgeolli increased the activation of caspase-3/7 and the apoptotic markers in AGS cells in a dose-dependent manner. Therefore, dealcoholized commercial Makgeolli can be used for cancer prevention.