长链非编码RNA ENST00000427974调控胃癌侵袭和转移的机制研究

Recurrence and metastasis have been the main causes of treatment failure in gastric cancer, and it is of great importance to regulate key molecules of cancer invasion and metastasis. Studies have shown that long noncoding RNAs play an important role in the development of malignancies. We have gained a signature of differentially expressed lncRNAs and mRNA between gastric cancer samples and paired adjacent non-tumor tissues from 5 patients with microarray analysis. Gastric cancer tissues harbored a significantly lower level of ENST00000427974, and ENST00000427974 has been demonstrated to play a vital role in suppressing epithelial-mesenchymal-transition, invasion and metastasis of gastric cancer. However, the precise molecular mechanism remains largely unknown. Thus, we hypothesize that ENST00000427974 may enhance the binding of FOXA2 to the promoter of Slug and repress its transcription, which contributes to the reversing of the epithelial-mesenchymal-transition process and the suppression of invasiveness and metastasis. To prove our hypothesis, we will use qRT-PCR and western blot analysis, transfection of vector and RNA inference technology to explore the role of ENST00000427974 in invasion and metastasis of gastric cancer. We will conduct research in gastric cancer cells, cancer cell metastasis nude mice model and human gastric cancer tissues.

胃癌复发及转移是胃癌治疗失败的主要原因，干预关键靶点以抑制胃癌复发转移对胃癌的综合治疗意义重大。研究显示长链非编码RNA在肿瘤的发生发展中发挥着重要作用。前期研究利用芯片筛选了胃癌组织相对于正常组织中差异性表达的lncRNA；胃癌组织中ENST00000427974表达异常降低，且在抑制胃癌细胞上皮间质转化及侵袭转移中发挥重要作用，但其中分子机制尚不明了。为此，我们提出假说，ENST00000427974可能促进FOXA2结合至Slug的启动子区域从而抑制Slug的转录，导致胃癌细胞发生上皮间质转化逆转及侵袭转移能力减弱。为了验证这一假说，我们将通过胃癌细胞、裸鼠肿瘤转移模型和人体标本，采用real time PCR、Western blot、病毒载体转染、RNA干扰等手段，从分子、细胞、组织以及动物整体水平等多方面探讨ENST00000427974在胃癌侵袭转移中的重要作用。

长链非编码RNA(lncRNA)在肿瘤的发生发展中起重要作用，但目前机制尚未完全阐明。我们利用人体胃癌组织及细胞系，探索lncRNA-GCAWKR在胃癌中的促癌作用。利用原位杂交检测42例胃癌患者中GCAWKR的表达水平，利用qRT-PCR检测123例胃癌患者组织中表达水平。调控胃癌细胞系中GCAWKR表达水平，并进行相关生物学及分子机制分析。GCAWKR在胃癌组织中表达水平显著高于正常组织，且表达水平与肿瘤大小、淋巴结转移、TNM分期及患者预后相关。GCAWKR可对胃癌细胞增值及侵袭产生影响。在分子机制上，GCAWKR与WDR5及KAT2A结合，并作为WDR5/KAT2A复合物的分子链接，调控WDR5/KAT2A复合物在靶基因启动子区域的结合。因此，我们的数据揭示了一个新的lncRNA在胃癌中促癌作用的分子机制，可以作为胃癌新的治疗靶点。