Beclin-1在胃癌血管生成拟态形成中的表达及意义

Expression and significance of Beclin-1 in vasculogenic mimicry formation of gastric cancer

目的 探讨胃癌细胞SGC7901在体外血管生成拟态（VM）的形成过程中,自噬特异性基因Beclin-1的表达情况及其对VM形成的影响.方法 分别将ShRNA整合质粒载体和空白质粒载体转染到胃癌细胞SGC7901中,采用RT-PCR及Western blot法检测SGC7901细胞中Beclin-1表达情况;并在体外构建VM模型,观察不同转染细胞中VM形成能力的差异,同时检测VM形成前后细胞中VM形成基因Notch-1的表达情况.结果 胃癌SGC7901形成VM过程中,Beclin-1及Notch-1 mRNA和蛋白表达均明显升高（均P＜0.05）.与转染空白质粒的SGC7901细胞相比,转染ShRNA整合质粒抑制Beclin-1后,VM形成的细胞管状结构的数目[（15.4±1.1）个比（37.8±1.9）个,P＜0.05]、长度[（316.8±24.6） mm比（385.1±14.2） mm,P＜0.05]和交点数[（11.6±1.1）个比（27.2±1.1）个,P＜0.05]明显减少,同时Notch-1表达亦明显下降（P＜0.05）.结论 Beclin-1通过维持胃癌细胞VM调节基因的稳定表达促使VM形成,抑制Beclin-1为胃癌的基因治疗提供了一个可能的新靶点.

Objective To explore the effect and mechanism of autophagy specific gene Beclin-1 in gastric cancer cell SGC7901 on vasculogenic mimicry （VM） forming ability.Methods Plasmid vectors with and without integrated shRNA were transfected respectively into SGC7901 cell line （Beclin1-inhibited group and negative control group）.Simple SGC7901 cell line was used as blank group.RT-PCR and Western blot were performed to examine the expression of Beclin-1 in 3 groups.Culture was used to construct the VM model in vitro.Different VM forming ability was measured and genes （beclin-1,notch-1） expression of each group was detected before and after VM formation.Results Beclin-1 and notch-1 expression increased significantly in the process of VM forming.When beclin-1 was inhibited,the formation of VM was limited and VM formative genes expression decreased.As compared to cells of negative control group,those of Beclin1-inhibited group had less number of VM forming cellular tube-like construction （15.4±1.1 vs.37.8±1.9,P〈0.05）,shorter length of such construction [（316.8±24.6） mm vs.（385.1±14.2） mm,P〈0.05],and less crossing point （11.6±1.1 vs.27.2±1.1,P〈0.05）.Conclusions Beclin-1 can promote VM formation through maintaining stable expression of gastric cancer cell VM regulating genes.Beclin-1 inhibition may be a new target for gastric cancer gene therapy.