MCP、血管内皮抑素抑制结肠癌肝转移的作用研究

Inhibitory effect of modified citrus pectin and endostatin on liver metastasis from colon cancer

目的修饰柑橘果胶(modified citrus pectin,MCP)和血管内皮抑素(endostatin,ES)已分别被证实能通过不同机制抑制肿瘤转移的形成。探讨不同浓度的MCP及与ES联用后对小鼠结肠癌肝转移的抑制作用。方法经小鼠脾脏下极包膜注入CT-26结肠癌细胞建立结肠癌肝转移模型。135只Balb/c小鼠随机分为阴性对照组、阳性对照组、低剂量MCP组、中剂量MCP组、高剂量MCP组、ES组、低浓度MCP+ES组、中浓度MCP+ES组和高浓度MCP+ES组。MCP加入饮用水中,各组浓度分别为0、0、0.01、0.025、0.05、0、0.01、0.025及0.05g/L,ES剂量均为2mg/kg,腹腔内给药,隔天1次。3周后观察各组小鼠肝转移情况。制作肝转移瘤组织芯片,用免疫组化方法检测肝转移瘤组织中galectin-3、VEGF的表达和肿瘤微血管密度(MVD),采用酶联免疫吸附实验(ELISA)方法检测小鼠血清galectin-3和VEGF浓度。结果(1)除阴性对照组外,各组肝转移率分别为100.0、80.0、73.3、60.0、86.7、73.3、73.3和60.0。高浓度MCP组、中浓度MCP+ES组、高浓度MCP+ES组与阳性对照组比较,肝转移灶数目均明显减少(P<0.05);高浓度MCP+ES组与ES组比较,肝转移灶数目明显减少(P<0.05)。(2)除阴性对照组外,各组脾脏种植瘤体积中位数分别为1.51cm3、0.93cm3、0.77cm3、0.70cm3、1.25cm3、1.15cm3、0.75cm3和0.67cm3。中浓度MCP组、高浓度MCP组、中浓度MCP+ES组、高浓度MCP+ES组与阳性对照组比较,脾脏种植瘤体积均明显缩小(P<0.05)。(3)各组肝转移瘤galectin-3、VEGF表达相互间比较无明显差异(P值均>0.05)。(4)阳性对照组和各治疗组的血清galectin-3、VEGF浓度均明显高于阴性对照组(P值<0.01);阳性对照组与各治疗组相互间比较无明显差异(P值均>0.05)。(5)各组肝转移瘤MVD分别为28.47±3.22、27.47±3.22、26.92±1.47、26.91±2.41、26.43±1.47、26.50±3.09、25.45±1.96和24.73±3.09,各浓度MCP+ES组肝转移瘤MVD计数与阳性对照组比较均有明显减少(P值均<0.05)。结论单用MCP或与ES联用均能有效抑制结肠癌肝转移和微血管生成。

Objective To investigate the inhibitory effect of modified citrus pectin （MCP） combined with endostatin （ES） on liver metastasis from colon cancer in mouse. Methods CT-26 colon cancer cells were injected into the subcapsule of spleen in Balb/c mouse to establish a colon cancer liver metastasis model. One hundred and thirty-five mouse were divided into 9 groups randomly： negative control group,positive control group,low MCP group,medium MCP group and high MCP group,ES group,low MCP＋ES group,medium MCP＋ES group and high MCP＋ES group. The concentrations of MCP in water were 0. 0, 0. 0,0. 01,0. 025,0. 05,0. 0,0. 01,0. 025,0.05 g/L,respectively. The concentration of ES was 2 mg/kg, injected into the abdominal cavity once every 2 days. The liver metastasis was observed after 3 weeks. The expressions of galectin-3, vascular endothelial growth factor （VEGF） and tumor microvessel density （MVD） in liver metastasis were examined with tissue microarray technique and immunohistochemistry. The concentrations of galectin-3 and VEGF in serum were detected by enzyme linked immunosorbent assay（ELISA）. Results The percentage of liver metastasis in each group was 100.0%,80.0%,73.3%,60.0%,86.70/oo ,73.3%,73.30% ,60. 0%. The number of liver metastases in high MCP group, medium MCP ＋ ES group and high MCP＋ES group was significantly fewer than that in positive control group （P〈0.05）. The number of liver metastases in high MCP＋ES group was significantly fewer than that in high MCP group （P〈0.05）. The median volume of spleen implanted tumor in each group was 1.51 cm^3 , 0.93 cm^3, 0.77 cm^3 , 0.70 cm^3, 1.25 cm^3, 1.15 cm^3 , 0. 75 cm^3and 0.67 cm^3. The size of spleen implanted tumor in medium MCP group,high MCP group ,medium MCP＋ES group and high MCP＋ES group was smaller compared with positive control group（P〈0. 05）. The expression of galectin-3 and VEGF in liver metastasis in each group was not significantly different （all P〉0.05）. The concentration of galectin-3 and VEGF in serum in positive control group and all treatment groups was significantly higher than that of negative group （P〈 0.01 ）. There was no significant difference between the positive control group and treatment groups （all P〉0. 05）. The MVD counts in liver metastases were 28.47±3.22,27.47±3.22,26. 92±1.47,26.91±2.41,26.43±1. 47,26.50±3.09, 25.45±1.96 and 24. 734±3.09,respectively. Compared with positive control group,the MVD of liver metastasis focus in ES group,low MCP＋ES group, medium MCP ＋ ES group and high MCP ＋ ES group was significantly lower （P 〈 0. 05）. Conclusion MCP alone or combine with ES can inhibit liver metastasis from colon cancer and angiogenesis effectively in mouse.