KDM5B促进胃癌侵袭、转移的作用及机制研究

KDM5B (histone demethylase) can regulate the expression of many tumor gene and it is closely related to the invasion and metastasis of tumor. Our previous study first found KDM5B significantly higher expression in gastric cancer through the screening of gastric cancer associated molecular markers and the histone H3K4 methylation level decreased significantly. When downregulated KDM5B expression, the expression of AKT protein also reduced and the migration and invasion ability of gastric cancer cell lines decreased significantly. These results suggest that KDM5B may influence the invasion and metastasis of gastric cancer cells by regulating the level of H3K4 methylation. This topic will design the deletion variant of KDM5B by overlap PCR and make clear the functional domain of KDM5B in the gastric cancer cells. And the binding sites of KDM5B and H3K4 will be examined by immunoprecipitation. Then, we can know the role of KDM5B and H3K4 in the invasion and metastasis of gastric cancer. We will elucidate the mechanism of KDM5B promoting invasion and metastasis in gastric cancer cells from signal transduction through chromatin immunoprecipitation sequencing, protein pathway microarray and bioinformatics analysis. And the gastric cancer tissues were collected to analyze the relationship between the expression of KDM5B and the level of H3K4 methylation in clinicopathological features and prognosis. So as to provide a new reference for the treatment and prognosis of gastric cancer.

组蛋白去甲基化酶（KDM5B）可以调控多种肿瘤基因的表达，与肿瘤的侵袭、转移性密切相关。我们前期实验通过对胃癌相关分子标记的筛选，率先发现KDM5B在胃癌中明显高表达，同时组蛋白H3K4甲基化水平明显减低，当下调胃癌细胞株中KDM5B表达后胃癌细胞的迁移及侵袭能力明显下降。提示KDM5B可能通过调节H3K4甲基化水平影响胃癌细胞的侵袭及转移。本研究拟应用重叠PCR法构建KDM5B功能结构域缺失体，明确胃癌细胞中KDM5B作用的功能结构域，并应用免疫共沉淀方法验证KDM5B与H3K4的结合位点，明确KDM5B与H3K4在胃癌侵袭、转移中的作用。应用染色质免疫共沉淀测序、蛋白通路微阵列以及生物信息学分析等技术从信号传导角度阐明KDM5B促进胃癌细胞侵袭、转移的机制。并收集胃癌组织标本，分析KDM5B表达、H3K4甲基化水平与临床病理特征及预后的关系，从而为胃癌的治疗及预后提供新的参考指标。

组蛋白去甲基化酶（KDM5B）可以调控多种肿瘤基因的表达，与肿瘤的侵袭、转移性密切相关。我们前期实验通过对胃癌相关分子标记的筛选，率先发现KDM5B在胃癌中明显高表达，同时组蛋白H3K4甲基化水平明显减低，当下调胃癌细胞株中KDM5B表达后胃癌细胞的迁移及侵袭能力明显下降，通过扩大检测 KDM5B 表达及 H3K4 甲基化水平的临床标本量，发现KDM5B在人胃癌病变中的表达显著上调，同时胃癌甲基化程度与患者的性别、年龄、肿瘤的大小、分化程度没有关系。而与肿瘤的浸润深度、淋巴结转移、TNM分期及远处转移密切相关。提示KDM5B可能通过调节H3K4甲基化水平影响胃癌细胞的侵袭及转移。本研究拟应用重叠PCR法构建KDM5B功能结构域缺失体，明确胃癌细胞中KDM5B作用的功能结构域，应用COIP实验明确 KDM5B 与 H3K4 相互结合，明确KDM5B与H3K4在胃癌侵袭、转移中的作用。应用染色质免疫共沉淀测序、蛋白通路微阵列以及生物信息学分析等技术从信号传导角度阐明KDM5B促进胃癌细胞侵袭、转移的机制。分析KDM5B表达、H3K4甲基化水平与临床病理特征及预后的关系，从而为胃癌的治疗及预后提供新的参考指标。