胃癌术后局部复发microRNA表达谱的分析

【作者】 张晓东； 张经余； 藏师竹； 郭瑞芳； 沈琳； 吕有勇；

【机构】 北京大学临床肿瘤学院北京肿瘤医院北京肿瘤研究所；

【摘要】 目的:胃癌是消化系统最常见的恶性肿瘤,即使进行了根治性手术,术后复发率仍相当高,是临床治疗失败导致死亡的主要原因。现有的临床诊断和检查方法难以做到预测复发和早期诊断。最近发现的与基因调节有关的 microRNAs在一些肿瘤中显示了良好的应用前景。方法:以我院胃癌根治术后局部复发的病例和未复发对照组为体系, 通过基因芯片技术筛选与胃癌复发相关的microRNAs。收集并分析胃癌根治术后临床资料完整的吻合口复发的病例11例, 未复发对照组13例,通过MicroRNAs array得到两组差异表达的microRNAs,预测可能受其调控的靶基因,从胃癌复发和未复发的基因表达谱数据库里得到与复发相关的基因, 再应用免疫组化在胃癌组织中进行验证。结果:通过Array 技术得到了20个差异表达的microRNAs其中11个上调和9 个下调,通过预测得到了4000个可能受其调控的靶基因。从胃癌基因表达谱数据库里,把4000个基因进行筛选,得到了 230个癌组织与其相匹配的正常组织有差别的基因。同时从胃癌复发和未复发的基因表达谱数据库里,把230个基因进一步进行筛选,得到了17个复发与未复发病人有差别的基因。这包括与细胞生长、增殖、代谢、血管异生等相关的重要基因, 如MELK,已经有大量资料表明它与肿瘤的发生有关系,并在胃癌组织标本中验证,癌和癌旁正常组织均有表达,很有可能与胃癌局部复发相关。结论:预测胃癌术后局部复发对临床很有意义,本研究通过对胃癌根治术后局部复发和未复发两组临床指标明确的病例进行MicroRNAs array分析,得到了差异表达的microRNAs,预测可能受其调控的靶基因, 经初步验证已证实有些靶基因在胃癌和癌旁正常组织均有表达,进一步深入的工作正在进行之中。更多还原

【Abstract】 Objective: Gastric cancer is one of the most commonly digestive system malignancies. Tumor recurrence is still the main reason led to death even after completely operation. It is difficult to predict tumor recurrence and early diagnosis with current clinical methods. But non-coding small RNAs that post-transcriptionally regulate gene expression shed light on cancer research and clinical treatment Methods: A total of 20 biopsy specimens were obtained from Beijing Cancer Hospital after completely operation. 11 local recurred used as test group, while 13 non-recurrence as control group. After RNA extraction, purification, hybridization, microarrays were scanned with a confocal scanner (CapitalBio Corp.) and images were analyzed to obtain differently expressed miRNAs. MiRNAs targeted genes can be further predicted by TargetScan software and further be confirmed by immunohistochemistry. Results: We identified 20 miRNAs including 11 up-regulated and 9 down- regulated ones related to gastric cancer recurrence based on microarray platform, which maybe regulate about 4000 genes predicted by TargetScan. After filtration by our previous obtained gene expression profile, a total of 17 different genes were identified in gastric cancer recurrence groups and non-recurrence ones, which were recognized to be involved in many functions such as cell growth, cell proliferation, metabolism and abnormal angiogenesis. For example, MELK, a Ser/Thr kinase, lots of data indicated that it was associated with cancer. MELK protein expressed in both cancer and matched normal tissues from our IHC results indicated that it might be involved in gastric cancer local recurrence. Conclusion: It’ s of great significance to predict local recurrence of gastric cancer using microRNAs array technique. We analyzed the specimens of both the test group and the control ones and obtained the differently expressed miRNAs and further predicted their targeted genes. Primary experiments have proved that some target genes are expressed both in gastric cancer and matched tissues. Further researches are going on to confirm their functions.更多还原