长链非编码RNA MEG3在胃癌中的表达及其与预后的关系

Expression of long non-coding RNA MEG3 and its relationship with the prognosis of human gastric cancer

目的:研究长链非编码RNA(long non-coding RNA,lnc RNA)母系表达基因3(maternally expressed gene 3,MEG3)在胃癌组织中的表达及其与预后的关系,并进一步探讨MEG3与凋亡相关蛋白P53、鼠双微基因2(murine double minute 2,MDM2)的相关性。方法:收集2012年9月至2013年6月青岛大学附属青岛市市立医院55例行手术治疗的胃癌切除标本(包括癌组织及对应的远端正常组织),实时荧光定量PCR(q RT-PCR)检测胃癌组织中MEG3的表达,并分析其与临床病理参数的关系;应用免疫蛋白印迹法(Western blot)检测胃癌中P53、MDM2蛋白的表达水平,并分析其与MEG3的相关性。结果:lnc RNA MEG3在胃癌组织的相对表达水平(7.98±0.19)低于所对应的正常组织(9.47±0.18,P<0.05);在胃癌组织(r=-0.627,P<0.001)及远端正常组织(r=-0.807,P<0.001)中,P53与MDM2的表达呈负相关;P53与MEG3的表达呈正相关(r=0.591,P<0.05),MDM2与MEG3的表达呈负相关(r=-0.346,P<0.05);MEG3高表达者较低表达者中位生存期明显延长。结论:MEG3在胃癌发生发展过程中起抑癌基因的作用;MEG3与P53、MDM2在胃癌发生发展的生物学机制上有重要联系;检测MEG3的表达水平对胃癌预后有潜在价值。

Objective：To investigate the expression of maternally expressed gene 3 （MEG3）, a long non-coding RNA gene, in gastric can-cer tissues;determine the relationship of MEG3 with the prognosis of gastric cancer;and explore the relationship between MEG3 and apoptosis-associated protein P53 as well as murine double minute 2 （MDM2）. Methods：Fifty-five consecutive patients with gastric cancer admitted to Qingdao Municipal Hospital for surgical treatment from September 2012 to June 2013 were included in this study. Gastric cancer and paired normal tissues were collected. The expression of MEG3 was tested through real-time quantitative poly-merase chain reaction （qRT-PCR）. Western blot analysis was used to detect the expression of P53 and MDM2 in gastric cancer and eval-uate their correlations with MEG3. Results：The expression of MEG3 decreased in cancer tissues （7.98±0.19） relative to the correspond-ing normal tissues （9.47±0.18） （P〈0.05）. P53 and MDM2 showed negative relationships in the gastric cancer and normal tissues. A posi-tive relationship was found between P53 and MEG3 （r=0.591, P〈0.05）, whereas a negative relationship was found between MDM2 and MEG3 （r=？0.346, P〈0.05）. The median survival time was significantly prolonged in patients with high MEG3 expression compared with patients with low MEG3 expression. Conclusion：MEG3 exerts an inhibiting effect on the development of gastric cancer. MEG3, P53, and MDM2 may have important relationships in the biological mechanisms of gastric cancer development. Detecting the expression level of MEG3 may be useful for the prognosis of gastric cancer.