胃癌是我国最常见的恶性肿瘤之一，尽管目前对胃癌的诊治取得了很大的进展，但胃癌的总体生存率仍然较低。近年来研究证实，环状RNA（circular RNA，circRNA）与肿瘤的发生发展密切相关。然而，circRNA在肿瘤中的鉴定、临床意义、生物学功能和分子机制还有很多未知。我们利用高通量RNA测序结合生物信息分析，筛选出在胃癌组织中异常表达的circRNA。其中有一个明显上调的circRNA引起了我们关注。它是由LMTK2基因的第10、11号外显子环化形成的，命名为circLMTK2。在进一步的实验中，我们初步发现circLMTK2在胃癌组织中高表达并具有促进胃癌细胞增殖的能力。本课题将在前期工作的基础上，进一步探讨circLMTK2在胃癌发生发展中的作用，为circRNA在胃癌中的研究提供新的理论依据，为胃癌的治疗提供新的治疗靶点。

Gastric cancer is one of the most common malignant tumors in china. Although the clinical diagnosis and treatment for gastric cancer have made great progress, the overall survival rate of gastric cancer is still relatively low. Recent studies have confirmed that circular RNA (circular RNA, circRNA) is closely related to the occurrence and development of tumor. However, the identification, the clinical significance, biological function and molecular mechanism of circRNAs in human cancers remain largely unknown. We had identified a set of circRNAs differently expressed in gastric cancer by using RNA sequencing technology and bioinformatics approaches. One of these circRNAs denoted circLMTK2, derived from the 10th and 11th exon of LMTK2, was found to be significantly upregulated in gastric cancer. Furthermore, we found that circLMTK2 was upregulated in GC tissues and has the potential to promote the proliferation of gastric cancer cells. In this project, we will demonstrate the role of circLMTK2 in GC to provide new evidence for the research of circRNA in gastric cancer and to provide new target for the therapy of gastric cancer.