THE EFFECT OF IN-VIVO NK CELL INHIBITION ON EXPERIMENTAL COLON ADENOCARCINOMA

Abstract

The host immune defence system plays an important role in preventing the spread of tumor cells in the body. In the present study, we evaluated the effect of natural killer (NK) cell activity in a mouse model of hepatic metastasis. One million colon cancer (C-26) cells were prepared in 0.05 ml of phosphate-buffered saline (PBS) and inoculated into the stomach wall (distal corpus) of Balb/c mice. The animals were divided into two groups. While control group animals received saline solution, the study group animals received anti-asialo GM-1 antiserum (1/10 dilution, 0.2 ml, 10 mg/ml) 24 h before the inoculation and the injections were repeated every 4 days throughout the experiment. All mice were sacrificed 21 days after tumor inoculation. Number of liver metastasis, wet liver weight, size and the weight of the tumor at injection site were evaluated. The tumor reached a bigger size (p=0.0022) and the number of metastatic nodules in the liver were much more (p=0.06) in the study group, compared with control. This study described that, depletion of mouse NK cell activity with anti-asialoGm-1 antiserum increased both primary tumor growth and metastatic liver colonies.