中文摘要：

目的研究YB-1抑制三氧化二砷（As2O3）诱导人胃癌BGC-823细胞自噬的机制。方法采用脂质体转染siRNA干扰YB-1和腺病毒转染pAdlEasy／YB-1过表达YB-1；实时荧光定量PCR检测Bcl-2和Beclinl基因转录；Westernblot检测YB-1、Bcl-2、Beclinl、P62和LC31I蛋白的表达；MDC染色、荧光显微镜观察自噬泡。结果与空病毒（AdGFP）组相比，pAdlEasy／YB-1（AdYB—1）组Bcl-2基因表达增高，而干扰质粒（siYB—1）组Bcl-2基因表达水平较空质粒（HK）组降低（P均〈0．05），各组Beclinl基因表达比较无统计学差异。与AdGFP和HK组相比，AdYB．1组Beclinl和LC3U蛋白减少，Bcl-2和P62蛋白增加（P均〈0．01），siYB-1组Beclinl和LC3II蛋白增加，Bcl-2和P62蛋白减少（P均〈0．01）。与AdGFP组相比，AdYB-1组自噬泡聚集减少，加入Bcl-2抑制剂HAl4-1后自噬泡重新聚集，Beclinl蛋白恢复表达，P62降解增加，LC31I升高。结论YB-1可能通过上调Bcl-2、抑制Bec—linl，实现对As，0，诱导的BGC-823细胞自噬的抑制。

英文摘要：

Objective To investigate the mechanisms of YB-1 inhibiting autophagy in gastric cancer BGC-823 cells induced by arsenic trioxide. Methods YB-1 and its siRNA recombined adenovirus vectors were transfected into BGC-823 cell lines, and the expression of YB-1 was tested after the transfection by Western-blot. Real time fluorescent quantitative PCR （ qRT-PCR ） was used to determine the mRNA levels of Bcl-2 and Beclinl. The protein expressions of YB-1, Bcl-2, Beclinl, P62 and LC3 were detected by Western-blot. MDC staining was used to observe the autophagic vacuoles. Results The expressions of Bcl-2 were enhanced after BGC-823 cells were transfected with YB-1 recombined adenovirus vectors. On the contrary, the expressions of Bcl-2 were reduced by transfecting YB-1 siRNA. The mRNA expression of Beclinl had no obvious differences among groups. Compared with the control groups, the protein expressions of Bcl-2 and P62 were increased and the expressions of Beclinl and LC3 Ⅱ protein decreased after BGC-823 cells were transfected with YB-1. On the contrary, the results of proteins detection were opposite by transfecting YB-1 siRNA. MDC staining showed that the autophagic vacuoles were decreased in BGC-823 cells over expressed YB-1. And autophagic vacuoles were increased after adding HA14-1 in BGC-823 cells with over expressed YB-1. Compared with AdYB1 group, the protein expressions of Beclinl and LC3 II increased, but P62 decreased after adding with HA14-1, which were detected by Western-blot. Conclusion YB-1 inhibits the autophagy of BGC-823 cell induced by As203 through up-regulating Bcl-2, down-regulating Beclinl.