人参皂苷Rg3对小鼠结肠癌原发瘤切除后肝转移瘤生长的抑制作用

Ginsenoside Rg3 inhibits growth of liver metastases in nude mice after surgical removal of primary tumor

目的:探讨人参皂苷Rg3对小鼠原发瘤切除后肝内转移瘤生长的荧光成像及血管生成的影响,阐明人参皂苷Rg3抑制原发瘤切除促进转移瘤生长的内在机制.方法:慢病毒转染建立稳定表达绿色荧光蛋白(green fluorescent protein,GFP)基因的BALB/c小鼠结肠腺癌细胞株(BALB/c micecolon adenocarcinoma cell line,CT-26),用细胞悬液法构建结肠癌肝转移瘤模型,分为原发瘤切除组、原发瘤未切除组、人参皂苷Rg3组.采用切除原发瘤及人参皂苷Rg3治疗10d,通过小动物活体成像系统观察肝转移瘤的生长情况.应用组织切片苏木素-伊红染色法,观察肿瘤转移灶情况.SP免疫组织化学法检测转移瘤MVD及细胞增殖,TUNEL技术检测转移瘤细胞凋亡.结果:应用慢病毒转染获得稳定表达高强度绿色荧光的CT-26-GFP细胞株.结肠癌肝转移模型治疗结束后,用波长470nm的蓝光激发,通过荧光活体成像系统观察剖离肝脏转移灶发出绿色荧光.原发瘤切除后,人参皂苷Rg3组平均肝转移灶荧光值较原发瘤未切除组及原发瘤切除组有明显的下降(314.17±54.23,388.82±25.97,427.18±44.31);人参皂苷Rg3组、原发瘤未切除组和原发瘤切除组转移瘤发生率分别为40%,50%,100%;平均肝脏质量分别为2.92g±0.60g,3.80g±0.33g,3.98g±0.52g;转移瘤血管密度分别为27.10±3.41,42.60±8.42,62.40±5.08;转移瘤细胞Ki67的表达分别为34.70±6.46,54.30±8.98,65.20±3.82;转移瘤细胞凋亡指数分别为28.37±3.86,12.50±2.99,9.90±2.88.结论:稳定表达绿色荧光蛋白的CT-26-GFP细胞系及其动物模型可以为原发瘤切除研究提供理想的实验材料,应用小动物活体成像系统能够客观定量评价肿瘤在小鼠肝脏的生长情况.人参皂苷Rg3明显抑制小鼠原发瘤切除后肝内转移瘤的生长,明显抑制转移瘤的血管生成及细胞增殖,促进细胞凋亡.

AIM：To investigate the effect of 20（R）-Ginsenoside Rg3 on the growth of hepatic metastasis in nude mice after surgical removal of primary tumor.METHODS：BALB/c mouse colon adenocarcinoma CT-26-GFP cell line was established by transfection of CT-26 cells with a lentiviral vector containing the enhanced green fluorescent protein（eGFP）gene.A nude mouse model of hepatic metastasis was then developed,and the mice were randomly divided into three groups：primary tumor resection group,primary tumor preservation group and Ginsenoside Rg3 group.After resection of the primary tumor and treatment with Ginsenoside Rg3 for 10 days,microvascular density（MVD）and cell multiplication of liver metastases were detected by immunohistochemistry,and tumor apoptosis was detected by TUNEL assay.The green fluorescence was observed using a fluorescence in vivo imaging system.RESULTS：The average fluorescence intensity of liver metastases in the Ginsenoside Rg3 group was significantly lower than that in the primary tumor preservation group and primary tumor resection group（314.17±54.23 vs 388.82±25.97,427.18±44.31）.The incidences of metastases in the Ginsenoside Rg3 group,primary tumor preservation group and primary tumor resection group were 40%,50%and 100%,respectively.The average weight of the liver,MVD,and labeling index of Ki67 were lower and TUNEL apoptotic index was higher in the Ginsenoside Rg3 group than in the primary tumor preservation group and primary tumor resection group（liver weight：2.92±0.60 vs 3.80±0.33,3.98± 0.52;MVD：27.10±3.41 vs 42.60±8.42,62.40± 5.08;labeling index of Ki67：34.70±6.46 vs 54.30 ±8.98,65.20±3.82;apoptotic index：28.37±3.86 vs 12.50±2.99,9.90±2.88）.CONCLUSION：20（R）-Ginsenoside-Rg3 could inhibit metastatic tumor growth,angiogenesis,proliferation and promote apoptosis in mice after surgical removal of primary tumor.