[Expression of galectin-3 in liver metastasis of colon cancer and the inhibitory effect of modified citrus pectin].
OBJECTIVE
To observe the expression of galectin-3 in the liver metastasis of colon cancer in mice and the inhibitory effect of modified citrus pectin (MCP) on galectin-3 expression.


METHODS
Seventy-five Balb/c mice were randomized into 5 groups, namely the negative control, positive control, low-concentration MCP, moderate-concentration MCP and high-concentration MCP groups. CT26 colon cancer cells were injected into the subcapsule of the mouse spleen to establish liver metastasis models of colon cancer, but the mice in the negative control group received no tumor cell injection. MCP was added into the drinking water of the mice at the concentrations of 0, 1.0%, 2.5% and 5.0% (m/V). The liver metastasis was observed 3 weeks after tumor cell inoculation. Enzyme-linked immunosorbent assay was performed to determine the serum galectin-3 level. A tissue microarray of the liver metastasis was prepared for immunohistochemical detection of galectin-3 expression in the liver metastasis.


RESULTS
In the positive control, low-, moderate- and high-concentration MCP groups, the rates of liver metastasis were 100%, 80%, 73.3% and 60%, respectively. The number of liver metastases in high-concentration MCP group was significantly smaller than that in the positive control group (P<0.05). In the 4 groups with tumor cell inoculation, the median volume of the primary lesions in the spleen was 1.51, 0.93, 0.77 and 0.70 cm(3), respectively, which were significantly smaller in the moderate- and high-concentration MCP groups than in the positive control group (P<0.05). The serum galectin-3 level in the positive control group and MCP-treated groups were significantly higher than that in the negative control group (P<0.01), but similar between the positive control group and the MCP-treated groups (P>0.05). In the positive control and the MCP-treated groups, the expression of galectin-3 in the liver metastases showed no significant differences (P>0.05).


CONCLUSIONS
The expression of galetin-3 is significantly increased in the liver metastasis of colon cancer, and MCP can effectively inhibit the liver metastasis.
Huang
Zhi-liang
ZL
Department of Abdominal Surgery, Affiliated Tumor Hospital of Guangzhou Medical College, Guangzhou, China. gzdlhy@yahoo.com.cn
Liu
Hai-ying
HY