目的·探讨川楝素（toosendanin，TSN）通过调节环状RNA circDLST对胃癌细胞BGC-823生长和侵袭的影响。方法·利用不同浓度TSN（0、0.5、1.0和2.0 μmol/L）处理胃癌细胞系BGC-823，24 h后定量PCR检测TSN对circDLST表达的影响。将circDLST过表达及其空载对照（CON）慢病毒载体转染胃癌细胞系BGC-823，然后以0.5 μmol/L TSN或PBS处理，即将细胞分为circDLST+TSN组、CON+TSN组和CON+PBS组；MTT增殖实验和Transwell侵袭实验观察细胞增殖和侵袭水平的变化。利用circDLST稳转细胞株BGC-823或对照细胞株建立裸鼠皮下移植瘤动物模型，然后每日腹腔注射200 μg/kg TSN或等量PBS，即将裸鼠分为circDLST+TSN组、CON+TSN组和CON+PBS组，观察皮下移植瘤的生长情况。结果·与对照组（0 μmol/L）比较，3种浓度的TSN均可显著下调circDLST的表达水平（均P<0.01），且呈浓度依赖性。TSN可抑制胃癌细胞增殖和侵袭能力，以及裸鼠皮下的移植瘤生长（均P=0.000），而circDLST过表达可逆转TSN的这些作用（均P<0.01）。结论·TSN可能通过下调circDLST抑制胃癌细胞BGC-823的生长和侵袭。

Objective · To investigate the effect of toosendanin (TSN) on the growth and invasion of gastric cancer cells BGC-823 by regulating circDLST expression. Methods · After gastric cancer cells BGC-823 were exposed to different concentrations of TSN (0, 0.5, 1.0, and 2.0 μmol/L) for 24 h, quantitative PCR was used to detect the expression of circDLST. BGC-823 cells were transfected with the circDLST overexpression lentiviral vector or its control vector (CON), and then treated with 0.5 μmol/L TSN or PBS. So the cells were divided into circDLST+TSN group, CON+TSN group and CON+PBS group. The viability and invasive potential of BGC-823 cells were observed by MTT proliferation test and Transwell invasion assay. The subcutaneous transplanted tumor models were established by using circDLST-transfected cell line BGC-823 or the control cell line in nude mice, and then 200 μg/kg TSN or the same volume of PBS was injected intraperitoneally every day. So the mice were divided into circDLST+TSN group, CON+TSN group and CON+PBS group. Results · Compared with the control group (0 μmol/L), all 3 concentrations of TSN decreased the expression levels of circDLST in a concentration dependent manner (P<0.01). TSN could significantly reduce the cell viability, cell invasion and subcutaneous xenograft tumor growth (P=0.000), while circDLST overexpression reversed the inhibitory effect of TSN (P<0.01). Conclusion · TSN may inhibit the growth and invasion of gastric cancer cells BGC-823 by downregulating circDLST expression.