榄香烯脂质体对人胃癌细胞HGC-27的体内外作用的初步研究

Preliminary research on the effect of elemene liposome on gastric cancer cell HGC-27 and its mechanism

背景与目的：近年来，许多研究表明榄香烯脂质体在临床治疗消化道肿瘤及其恶性胸腹水中应用广泛。本研究结合体内和体外实验旨在观察榄香烯脂质体对人胃癌细胞HGC-27生长的抑制作用。方法：在体外实验中，应用机器视觉一全自动活细胞观测分析系统（Cell—IQ）对不同浓度下的榄香烯脂质体进行观测，以筛选出对人胃癌HGC-27细胞产生抑制作用的最佳浓度，并通过流式细胞术分析在最佳浓度下，榄香烯脂质体对人胃癌细胞HGC-27凋亡的影响。在胃癌腹膜转移的裸鼠模型中，观察榄香烯脂质体、顺铂（cisplatin，DDP）等药物对裸鼠腹膜肿瘤指数（peritoneal cancer index，PCI）的影响，并用免疫组化检测CD31标记的肿瘤微血管密度（microvessel density，MVD）及血管内皮生长因子（vascular endothelial growth factor, VEGF）在肿瘤中的表达，以期对榄香烯脂质体抑制胃癌HGC-27细胞腹膜转移的机制进行探讨。结果：榄香烯脂质体作用于人胃癌细胞HGC-27后，Cell—IQ分析抑制作用随浓度增加，逐渐增强，以100gg／mL为最佳，榄香烯脂质体浓度再增高，其抑制肿瘤作用不再增强。最佳作用时间为4～19h。应用流式细胞术检测，100gg／mL榄香烯脂质体作用于人胃癌HGC-27细胞24h后，肿瘤细胞凋亡率为45％，对照组仅有0．019％。处理组的细胞凋亡率明显高于对照组。人胃癌腹膜转移裸鼠模型建立后给予榄香烯脂质体等药物干预，腹膜转移瘤PCI指数有明显差异，其中以联合治疗组下降明显，免疫组化检测发现CD31-MVD及VEGF蛋白表达与对照组差异无统计学意义（P〉0．05）。结论：榄香烯脂质体对于人胃癌细胞有明确抑制作用，最佳质量浓度为100μg／mL，最佳作用时间为4～19h；榄香烯脂质体对人胃癌裸鼠腹腔转移有明确预防作用；榄香烯脂质体对人胃癌细胞抑制作用的主要机制可能为诱导凋亡。

Background and purpose： In recent years, many studies have showed that elemene liposome is widely used in the treatment of digestive tract tumors, malignant pleural effusion and ascites. This study combined in vitro and in vivo experiments to observe the inhibitory effect of elemene liposome on the growth of human gastric cancer and the HGC-27 cell line. Methods： In order to screen the optimum concentration of elemene liposome, machine vision automatic live cell observation analysis system （Cell-IQ） was applied to detect the best inhibitory effect on human gastric cancer cell line HGC-27, and the flow cytometry was applied to further detect the apoptosis of HGC-27 treated with elemene liposome. The model of human gastric cancer peritoneal metastasis in nude mice was established to investigate the intervention of elemene liposome and cisplatin （DDP） on peritoneal cancer index （PCI）. CD31 marker of tumor microvessel density （MVD） and the expression of vascular endothelial growth factor （VEGF） in tumor tissues were investigated to explore the mechanism underlying the inhibitory effect on peritoneal metastasis of HGC-27 cells in nude mice. Results： CelMQ analysis showed that the inhibitory effect of elemene liposome on HGC-27 presented in a positive concentration-dependent manner, which could not be further enhanced when the concentration exceeded 100 μg/mL with the best reaction time between 4 and 19 hours. Flow cytometry showed that the early apoptosis rate was 45% in the elemene liposome group and only 0.019% in the control group. The early apoptosis rate was significantly higher in treatment group than that in control group （P〈0.05）. PCI was significantly lower in the group treated with elemene liposome plus DDP than that in control group （P〈0.05） in the peritoneal metastasis of gastric cancer nude mice model. The expression of CD31-MVD and VEGF was not significantly different between the treated and control groups （P〉0.05）. Conclusion： Elemene liposome can inhibit human gastric cancer cells at the optimal concentration of 100 μg/mL with the best reaction time between 4-19 hours. Elemene liposome has a clear preventive effect on peritoneal metastasis of human gastric cancer in nude mice. Induction of apoptosis in gastric cancer cells may be the main mechanism underlying the inhibitory effect of elemene liposome on human gastric cancer cells.