黄芪多糖增强裸鼠胰腺癌移植瘤对吉西他滨的化疗敏感性的作用机制

Mechanism of astragalus polysaccharide in enhancing the chemosensitivity of gemcitabine in nude mice transplanted with pancreatic cancer

目的分析黄芪多糖增强裸鼠胰腺癌移植瘤对吉西他滨的化疗敏感性的作用机制。方法选取人胰腺癌PANC-1细胞株建立裸鼠胰腺癌移植瘤模型40只,按处理方案分为4组:空白对照组、黄芪多糖组、吉西他滨组、黄芪多糖+吉西他滨组,每组10只,21 d后分离肿瘤组织称重,TUNEL染色检测凋亡,透射电镜检测自噬,QRT-PCR和Western blot检测凋亡相关基因(Bcl-2、Bax)、自噬相关基因(Beclin-1、P62、LC3Ⅱ/LC3Ⅰ)的mRNA和蛋白表达。比较各组瘤体积、平均瘤质量、抑瘤率、肿瘤组织坏死率、肿瘤组织中凋亡细胞数、Bcl-2、Bax、Beclin-1、P62、LC3Ⅱ/LC3Ⅰ蛋白表达。结果空白对照组、黄芪多糖组、吉西他滨组及黄芪多糖+吉西他滨组的瘤体积、平均瘤质量呈下降趋势(P<0.01);黄芪多糖组、吉西他滨组及黄芪多糖+吉西他滨组的抑瘤率、肿瘤组织坏死率呈上升趋势(P<0.01);黄芪多糖组、吉西他滨组及黄芪多糖+吉西他滨组TUNEL表达平均值均高于空白对照组,黄芪多糖+吉西他滨组TUNEL表达平均值高于黄芪多糖组、吉西他滨组(P<0.01)。与空白对照组相比,黄芪多糖组、吉西他滨组及黄芪多糖+吉西他滨组肿瘤组织Bcl-2、P62较低,Bax、Beclin-1以及LC3Ⅱ、LC3Ⅰ较高(P<0.05);与黄芪多糖组相比,吉西他滨组Bcl-2、P62较低,Bax、Beclin-1及LC3Ⅱ、LC3Ⅰ较高(P<0.05);与吉西他滨组相比,黄芪多糖+吉西他滨组Bcl-2、P62较低,Bax、Beclin-1以及LC3Ⅱ、LC3Ⅰ较高(P<0.05)。结论黄芪多糖能够有效抑制胰腺癌移植瘤生长,且与吉西他滨共同使用具有一定的增效作用,其作用为促癌细胞凋亡。

Objective To analyze the mechanism of astragalus polysaccharide enhancing the chemosensitivity of gemcitabine in nude mice transplanted with pancreatic cancer.Methods Forty nude mouse models of transplanted pancreatic cancer were established by selecting human pancreatic cancer PANC-1 cell line.According to the treatment scheme,they were divided into four groups:blank control group,astragalus polysaccharide group,gemcitabine group,and astragalus polysaccharide+gemcitabine group,with 10 in each group.After 21 days,tumor tissue was separated and weighed.Tunel staining was used to detect apoptosis.Transmission electron microscopy was used to detect autophagy.QRT-PCR and Western blot were used to detect the mRNA and protein expression of apoptosis related genes(Bcl-2,Bax),autophagy related genes(Beclin-1,P62,LC3Ⅱ/LC3Ⅰ).Compare the tumor volume,average tumor mass,tumor inhibition rate,tumor tissue necrosis rate,number of apoptotic cells in tumor tissue,Bcl-2,Bax,Beclin-1,P62,LC3Ⅱ/LC3Ⅰprotein expression among different groups.Results The tumor volume and average tumor mass of blank control group,astragalus polysaccharide group,gemcitabine group and astragalus polysaccharide+gemcitabine group were decreased(P<0.01).The tumor inhibition rate and tumor necrosis rate of astragalus polysaccharide group,gemcitabine group and astragalus polysaccharide+gemcitabine group were increased(P<0.01).The mean value of TUNEL expression in astragalus polysaccharide group,gemcitabine group and astragalus polysaccharide+gemcitabine group were higher than those in blank control group,and the mean value of TUNEL expression in astragalus polysaccharide+gemcitabine group were higher than those in astragalus polysaccharide group and gemcitabine group(P<0.01).Compared with blank control group,Bcl-2 and P62 in astragalus polysaccharide group,gemcitabine group and astragalus polysaccharide+gemcitabine group were lower,while Bax,Beclin-1,LC3Ⅱand LC3Ⅰwere higher(P<0.05).Compared with astragalus polysaccharide group,Bcl-2 and P62 were lower,while Bax,Beclin-1,LC3Ⅱand LC3Ⅰwere higher in gemcitabine group(P<0.05).Compared with gemcitabine group,Bcl-2 and P62 were lower,while Bax,Beclin-1,LC3Ⅱand LC3Ⅰwere higher in astragalus polysaccharide+gemcitabine group(P<0.05).Conclusion Astragalus polysaccharide can effectively inhibit the growth of transplanted tumor of pancreatic cancer,and has a certain synergistic effect when combined with gemcitabine.Its role is to promote apoptosis of cancer cells.