中文摘要：

背景细胞的自噬是肿瘤细胞非凋亡形式的死亡过程，研究证实三氧化二砷（As2O3）可诱导肿瘤细胞凋亡，但As2O3是否可致SO—Rb50细胞发生自噬的研究鲜有报道。目的探讨As2O3体外诱导SO—Rb50细胞自噬的作用。方法用浓度为0．5、1．0、2．0、4．0μmol／L的As2O3培养液及不含As2O3的未处理组处理SO—Rb50细胞系48h，采用MTT法测定各As2O3，浓度组SO—Rb50细胞的吸光度（As2O3）值。构建自噬标志物磷酸化绿色荧光蛋白（pGFP）-LC3体外转染SO—Rb50细胞，并分为新鲜RPMI一1640培养组（未处理组）、As2O3，RPMI一1640培养组（As2O3处理组）和rapamycin培养组（阳性对照组），于48h后行激光共焦显微镜检测细胞自噬；用自噬特异性染料单丹磺酰戊二胺（MDC）行荧光染色检测SO—Rb50细胞的自噬，并用透射电子显微镜检测SO—Rb50细胞的自噬表现，采用流式细胞仪定量检测不同浓度As2O3，处理组自噬泡阳性细胞百分比。结果未处理组和0．5、1．0、2．0、4．0txmolAs2O3，作用48h后SO—Rb50细胞的A570值分别为2．194＋0．066、1．841±0．213、1．035±0．046、0．374±0．042和0．167±0．019，总体比较差异有统计学意义（F=547．636，P〈0．05），其中各浓度As2O3组A。值均明显低于未处理组，差异均有统计学意义（均P=0．000）。As2O3处理组和阳性对照组可见GFP—LC3融合蛋白呈点状聚集在相应的自噬泡，未处理组GFP—LC3呈弥散分布。透射电子显微镜检查可见未处理组SO—Rb50细胞超微结构正常，As2O3处理组和阳性对照组见大量双层膜状结构及自噬溶酶体。未处理组48h见极少量MDC阳性荧光颗粒，As2O3处理组及阳性对照组48h可见明显的MDC阳性荧光颗粒，聚集在细胞质相应的自噬发生区。流式细胞术检测发现未处理组和0．5、1．0、2．0、4．0μmol／LAs2O3及rapamycin作用48h后自噬泡阳性的SO—Rb50细胞百分比分?

英文摘要：

Background Cellular autophagy is a non-apoptosis death form of tumor tissue. Research determined that arsenic trioxide （As2O3） leads to apoptosis of tumor cells. But whether As2O3 induce autophagy of SO-Rb50 cells or not is unclear. Objective This study was to assess the effects of As2O3 on autophagy of SO-Rh50 cells. Methods As2O3 with the concentration of 0,0. 5,1.0,2.0,4.0 p.mol/L was used to treat the SO-Rb50 cell line for 48 hours,and the growth and proliferation of SO-Rb50 ceils were detected using MTT assay （A570 ） . pGFP- LC3 ,a marker of autophagy,was constructed to transfer SO-Rb50 cells, and the cells were then divided into RPMI- 1640 culture group （ untreated group） , As2O3 ＋ RPMI-1640 culture group （ As2O3 treated group） and rapamycin culture group （positive control group）. Autophagy of SO-Rh50 cells was examined by laser confocal microscope and monodansylcadaverine （MDC） influorescence staining, respectively,48 hours following cell culture, ghrastructural features of autophagy were examined with transmission electron microscope （TEM）. The percentage of autophagy positive cells in different concentrations of As203 treated groups was calculated with flow eytometer. Results The A570 values of SO-Rb50 cells were 2. 194-＋0. 066,1. 841-＋0. 213,1. 035-＋0. 046,0. 374-＋0. 042 and 0. 167-＋0. 019 in 0,0.5,1.0,2.0,4.0 p.mol/L As2 03 treated groups, with a significant difference among these 5 groups （ F = 547. 636,P〈0. 05 ）, and those of 0. 5,1.0,2. 0,4.0 μmol/L As203 treated groups were significantly reduced in comparison with untreated group （P = 0. 000）. The positive granular spots for GFP-LC3 chimeric protein were seen to aggregate in autophagic vacuoles in the As2O3 treated group and positive control group,but diffuse cytoplasmic signal for GFP-LC3 was found in the untreated group. Normal ultrastructure of SO-Rb50 cells was exhibited in the untreated group, and many double-membrane-like bound vesicles and autlysosomes were documented in the As203 treated gr