[Inhibitory effects of two oligosaccharides on murine melanoma experimental metastasis].

OBJECTIVE: To observe the effects of a chemically synthesized tetrose and a natural yeast mannan on mouse melanoma experimental liver metastasis. METHODS: After treated with 4 mg tetrose (tetrose group) or 4 mg mannan (mannan group) for 30 minutes at 37 degrees C, 0.5 ml 1 x 10(6)B16-MBK melanoma cells were injected intraspleen. 55 days later, melanoma metastasis nodes in the surfaces of the liver and other organs as well as mouse survival time were observed. RESULTS: Of 6 mice in control (B16 cell+PBS), 4 died naturally within 55 days, 2 were dissected in the 55th day. All of the 6 mice had metastases in the livers, the total number of the melanoma nodes on each liver surface ranged from 2 to 30, with the largest one fused to the whole liver. One mouse had a neoplasm in the remnant site of injection, 3 had metastases in lungs, while of the 6 mice in the tetrose group, one died on the 50th day on injection. In mannan group, all of the 6 mice survived and no metastasis was seen except the largest diameter of < 1 mm of 2 liver nodes in one mouse. Neither tetrose nor mannan group had metastasis of the liver, and the weights of liver in the two groups were significantly lower than in the control. CONCLUSION: Both tetrose and mannan had the effects in blocking melanoma experimental liver metastasis, inhibiting transmigration of the liver, and prolonging the survival time of the mouse.