肿瘤转移是影响胃癌患者预后的重要因素。本课题组前期发现接头蛋白CRKL与胃癌浸润、转移等恶性表型密切相关，敲低CRKL能显著抑制胃癌侵袭迁移，但具体机制不明。通过特征基因数据挖掘发现，SLC7A5与CRKL表达呈正相关。进一步实验表明，敲低CRKL，SLC7A5表达下调。此外，SLC7A5基因具有转录因子HIF2α潜在结合位点，而HIF2α表达与CRKL相关。据此，我们推测CRKL、HIF2α、SLC7A5间存在调控关系。本课题拟阐明上述CRKL通路影响胃癌转移的分子机制，为后续探索相关分子靶向治疗奠定基础，具体内容包括：1）调节胃癌细胞CRKL、HIF2α、SLC7A5表达，观察转移相关生物学行为变化；2）探讨CRKL、HIF2α、SLC7A5间作用关系，结合临床明确它们在胃癌转移中的意义；3）通过荧光素酶报告基因、ChIP等技术，明确CRKL经HIF2α调控SLC7A5表达的作用机制。

Tumor metastasis is an important prognostic factor for gastric cancer, related with complex molecular mechanisms. Our previous research found that CRKL aberrant expression in gastric cancer is significantly related with the malignant behaviors of invasion and metastasis. By knocking down CRKL in gastric cancer cells, the ability of invasion and migration of tumor cells was significantly depressed. However the mechanism of how CRKL drives the metastasis in gastric cancer is unknown. Our preliminary work discovered that the expression of SLC7A5 is correlated with CRKL. And the depletion of CRKL in gastric cancer could significantly induce the decreasing of SLC7A5 expression. Moreover, we found two potential binding site of SLC7A5 interacting with HIF2α, who is an important transcription factor involving in tumorigensis. Therefore, we assume that there could be a potential regulating relationship between these three molecules. The aim of this study is to investigate the pathway of CRKL regulating SLC7A5 through HIF2α, and to provide pre-clinical data for the target therapeutic treatment. In details: (1) we will observe the consequent cellular biological changes by modifying the gene expression of CRKL, HIF2α and SLC7A5 in gastric cancer cells; (2) we will study the relationship and interaction among CRKL, SLC7A5 and HIF2α in gastric cancer metastatic process; (3) we will validate the mechanism of the CRKL-HIF2α-SLC7A5 pathway by applying bio-techniques including luciferase reporter gene assay and chromatin immunoprecipitation.