中国是胃癌发病大国，但发病和转移机制有待于深入研究。转录因子和miRNA作为两种关键调控因子在转录和转录后水平中发挥重要作用。预实验发现，转录因子HOXD9在胃癌中表达明显上调，可能促进胃癌细胞侵袭及转移；通过miRNAs芯片得到HOXD9潜在下游分子miR-3618和miR-1306-5p；检测miR-3618和miR-1306-5p基因簇在胃癌中的表达状况并评估其生物学功能；生物信息学分析提示AQP1可能是miR-3618和miR-1306-5p下游共同靶基因。因此，我们提出假设：转录因子HOXD9是致癌基因，过表达HOXD9可抑制miR-3618/1306-5p基因簇进而促进AQP1的表达，共同调节胃癌细胞侵袭和转移。本项目拟探讨HOXD9、miR-3618/miR-1306-5p及AQP1生物学功能及分子机制，将加深对胃癌分子机制的理解，为研制新型抗肿瘤药物提供理论依据。

The incidence of gastric cancer is very high in China with unknown mechanism of tumorigenesis and metastasis. Transcription factor and miRNA, as two key regulatory factors, play an important role in transcription and post-transcription. In our preliminary data, we found that transcription factor HOXD9 expression is obviously upregulated in gastric cancer, indicating that it may promote cell invasion and migration. miR-3618 and miR-1306-5p are predicted as downstream targets of HOXD9 through miRNAs array. Next, we will detect the expression and molecular functions of miR-3618 and miR-1306-5p in gastric cancer. Bioinformatics analysis suggested that AQP1 may be the cross downstream target gene of miR-3618 and miR-1306-5p. Hence, we hypothesis that HOXD9 is an oncogene in gastric cancer; Overexpression of HOXD9 may inhibit the miR-3618/miR-1306-5p cluster expression, thus inducing AQP1 expression to regulate cell invasion and migration in gastric cancer. This project will explore the molecular function of HOXD9, miR-3816/miR-1306-5p and AQP1 in gastric cancer. It will deepen the understanding of the molecular mechanism of gastric cancer and provide a theoretical basis for the development of new anti-tumor drugs.