中文摘要：

人类母系表达基因3（MEG3）是目前研究最为广泛的长链非编码RNAs（lncRNAs）之一，在肿瘤的发生发展和侵袭转移等过程中发挥着重要的作用。最近，大量研究结果表明MEG3在多种肿瘤的癌组织中的表达水平明显低于癌旁正常组织，在正常机体中发挥着抑癌基因的作用。也有研究者发现癌组织中MEG3处于低表达状态时提示着肿瘤可能发生转移。本研究目的是综合分析癌症病人中MEG3表达水平与肿瘤转移发生率间的关系，探讨MEG3是否可以作为判断患者发生肿瘤转移的潜在标志物。本次研究利用计算机检索维普数据库、万方数据库、中国知网（CNKI）数据库和PubMed数据库，检索时间截止至2016年4月。收集符合标准的所有研究，利用Meta分析进行数据处理并探讨MEG3表达水平与患者肿瘤转移发生率间的关系。Meta分析共纳入5个研究，包括302例样本资料。结果表明：MEG3低表达组中的患者发生肿瘤转移人数较MEG3高表达组多。说明癌症病人中MEG3的表达水平与肿瘤转移发生率相关，MEG3低表达的患者发生肿瘤转移的概率明显高于MEG3高表达的患者。因此，MEG3可以作为预测癌症患者是否发生肿瘤转移的潜在生物标志物。

英文摘要：

Human maternally expressed gene 3 （MEG3）, a well-known long noncoding RNA, has been clarified to play significant roles during the occurrence, development, invasion and metastasis of tumors. Recently, a large number of studies have indicated that the expression level of MEG3 in many kinds of tumor tissues is significantly lower than that in normal tissues, and plays the role of tumor suppressor genes in normal human body. Researchers have also found that it could predict neoplasm metastasis when MEG3 is in a low state of expression in cancer tissue. The purpose of this study was to analyze the relationship between MEG3 expression level and tumor metastasis in cancer patients, and to explore whether MEG3 could be a potential marker for judging the occurrence of tumor metastasis. Literature collections were conducted by searching VII？ database, Wanfang database, China National Knowledge Infrastructure （CNKI） database and PubMed database, and retrieval deadline was April, 2016. We collected all studies that meet the standard. Meta-analysis was used to analyze the data and explore the relationship between MEG3 expression and tumor metastasis. A total of 302 patients from 5 studies were included in this meta-analysis. Results demonstrated that the number of tumor metastasis in MEG3 low expression group was higher than that in MEG3 high expression group. Meta-analysis results showed that the expression level of MEG3 in cancer patients was correlated with tumor metastasis, and the incidence of tumor metastasis in patients detected with low MEG3 expression was higher than that in patients with high MEG3 expression. It suggested that MEG3 could be used as a potential biomarker for predicting the neoplasms metastasis of cancer patients.