作者：李荣辉，王玉，郑丽红，张春晶，许惠玉，张英博，潘洪明
【摘要】 目的研究树舌多糖(Ganoderma applanatum polysaccharides,GAPS)粗提物对人胃粘液性腺癌MGC-803细胞增殖、细胞周期及其对受体蛋白酪氨酸激酶EGFR表达的影响，探讨树舌多糖抗肿瘤作用机制。方法MTT法检测不同时间不同浓度树舌多糖对胃癌细胞MGC-803增殖抑制作用;流式细胞仪检测2.0 g/L树舌多糖作用72 h后MGC-803细胞的周期分布，流式细胞仪检测和免疫荧光显微镜观察树舌多糖对MGC-803细胞EGFR表达的影响。结果树舌多糖对胃癌细胞MGC-803具有增殖抑制作用，并呈时间及浓度依赖性。2.0 g/L树舌多糖作用72 h后，MGC-803细胞被阻滞于G0/G1期，S期和G2/M期细胞减少，与细胞对照组比较有差异，具有统计学意义(P<0.05)。荧光显微镜下观察树舌多糖组MGC-803细胞EGFR荧光强度较对照组明显减弱;流式细胞仪检测树舌多糖能下调MGC-803细胞EGFR表达，与细胞对照组比较有差异，具有统计学意义(P<0.05)。结论树舌多糖可以抑制胃癌MGC-803细胞的增殖，这与树舌多糖能够阻止肿瘤细胞由G1期进入S期、延缓细胞周期进程，降低受体型酪氨酸蛋白激酶EGFR的表达、阻断细胞增殖信号转导途径的信息传递有关。
【关键词】 树舌多糖; MGC-803细胞; 增殖; 细胞周期
Abstract：ObjectiveTo study the effects of crude polysaccharide extracted from Ganoderma applanatum (GAPS) on proliferation, cell cycle and EGFR expression of human gastric cancer cell line MGC-803 and its possible mechanisms. MethodsMTT assay was used to investigate the inhibitory effect of GAPS on MGC-803 which was treated with different concentration of GAPS for 24 , 48 and 72 h. Cell cycle and expression of EGFR were analyzed by flow cytometry (FCM). The fluorescence intensity of EGFR expression in MGC-803 cells was observed by fluorescence microscope. ResultsGAPS inhibited the proliferation of MGC-803 cells in dose-dependent and time-dependent manners. After MGC-803 cells were treated with 2.0 g/L GAPS for 72 h, cell cycle was arrested at G0/G1 phase with statistic significance of difference compared with control group (P<0.05) . The fluorescence intensity of EGFR expression in GAPS treated group cells was weakened which consistanted with the results of FCW that GAPS can decrease the expression of EGFR in MGC-803 cells with statistic significance difference compared with control group (P<0.05) .ConclusionGAPS can inhibit the proliferation of gastric carcinoma MGC-803 cells and prevent cell cycle from stepping down proceeding, arresting at G0/G1 phase ;GAPS can decrease the expression of EGFR so that it can inhibit MGC-803 proliferation by blocking information transmission of cell proliferation signal transduction pathway.
Key words： GAPS; MGC-803 cell ; Proliferation; Cell cycle
树舌Ganoderma applanatum又称“老牛肝”“扁芝”或“扁木灵芝”，是一种大型担子菌，灵芝科植物树舌灵芝的干燥子实体。我国大部分地区均有分布，生长在阔叶树树干上或根部，其性平，味微苦，具有清热、止痛、化积、止血、化痰、抗癌等功效。国内学者对树舌多糖抗肿瘤作用的实验研究，从增加宿主免疫功能到对肿瘤细胞的直接作用、对癌基因,抑癌基因的调控以及对蛋白质组表达的影响等研究[1～7]。本实验通过树舌多糖作用于体外培养胃癌细胞MGC-803，观察其对胃癌细胞增殖和EGFR表达的影响及探讨机制。
