DENNDlA调控Rab35/PI3K信号通路促进子宫内膜癌恶性进展的机制研究

The incidence of endometrial cancer (EC) is increasing, but the pathogenesis of EC is unclear. Polycystic ovary syndrome (PCOS) is a risk factors of the EC. DENND1A genetic SNP is associated with PCOS and EC. DENND1A activates Rab35 influencing the formation of the cytoskeleton. DENND1A SNP may be the key factor between PCOS and EC. However the role and the mechanism of DENND1A in EC are not clear. Our previous study found that the gene copy number of DENNDlA was increased in metastatic EC tissue. DENNDlA protein expression was higher than that in the controls. The expression of DENNDlA was correlated with Rab35, Akt and CD1 in EC. We will further explore the potential role of DENND1A which whether can regulate Rab35/PI3K signaling pathway to promote EC progression. In this project, we plan to focus on the following three fields: First,we will enlarge the clinical sample to observe the alteration and clinical significance of DENND1A and key proteins levels in Rab35/PI3K signaling pathway in EC to investigate the correlation between DENND1A and Rab35/PI3K pathway. Second, in vitro we will investigate whether and why DENND1A regulate Rab35/PI3K signaling pathway to promote EC progression. Finally, in vivo we will investigate wether DENND1A promote EC xenografted growth and metastasis. This research will help us get a better understanding of the etiology and pathogenesis of EC and provide a new marker for individualized treatment and prevent recurrence of EC.

子宫内膜癌(EC)发病率上升，但发病机制不明。多囊卵巢综合征（PCOS）为EC的高危因素，DENND1A基因改变与PCOS及EC相关，可激活Rab35影响细胞骨架形成。DENND1A改变可能为连接PCOS与EC的关键因子，但在EC中的作用机制不清。前期发现DENNDlA基因在转移EC组织高表达，EC中DENNDlA蛋白表达高于对照，且与Rab35、Akt、CD1表达呈正相关。本课题进一步探索DENND1A是否调控Rab35/PI3K信号通路促进EC恶性进展：①临床探讨DENND1A与EC临床病例特征、预后及其与Rab35/PI3K信号通路蛋白的相关性；②体外实验上调或下调DENND1A表达后对EC细胞恶性表型的影响及Rab35/PI3K信号通路关键蛋白的变化；③动物实验研究DENND1A对EC裸鼠移植瘤生长、转移的影响及机制。本课题对EC发病机理提供理论支持，为防治EC提供新的靶点。

子宫内膜癌(EC)发病率上升，但发病机制不明。多囊卵巢综合征（PCOS）为EC的高危因素，DENND1A基因改变与PCOS及EC相关，可激活Rab35影响细胞骨架形成。DENND1A改变可能为连接PCOS与EC的关键因子，但在EC中的作用机制不清。本课题研究发现a) 子宫内膜癌组织中DENND1A的蛋白表达均高于癌旁组织。DENND1A在NE、AHE、EC组织中均有表达，且阳性表达率逐渐升高。在子宫内膜样腺癌中DENND1A的阳性表达FIGO分期早、无淋巴结转移有关，DENND1A阳性表达组的预后高于DENND1A阴性表达组。b) 子宫内膜癌组织中Rab35的蛋白表达均高于癌旁组织。Rab35在NE、AHE、EC组织中均有表达，且阳性表达率逐渐升高，EC组织中的表达显著高于NE组织和AHE组织，在子宫内膜癌中Rab35的阳性表达与EC患者FIGO分期晚，肌层浸润深，有淋巴结转移有关，在子宫内膜癌患者中Rab35阳性表达组的预后低于Rab35阴性表达组。c) DENND1A-腺病毒感染HEC-1B细胞，可上调HEC-1B细胞DENND1A表达，上调DENND1A表达抑制HEC-1B细胞增殖、迁移、侵袭；上调DENND1A表达，磷酸化Akt水平降低、细胞周期蛋白（CyclinD1）的表达降低。d) DENND1A-慢病毒感染HEC-1A细胞，可下调HEC-1A细胞DENND1A表达，下调DENND1A表达促进HEC-1A细胞增殖、迁移、侵袭；下调DENND1A表达后，磷酸化Akt水平增加、细胞周期蛋白（CyclinD1）的表达增加。e) 动物实验发现上调DENND1A后，子宫内膜癌裸鼠移植瘤生长降低，转移瘤数量减少。下调DENND1A后子宫内膜癌裸鼠移植瘤生长增加，转移瘤数量增加。本课题对EC发病机理提供理论支持，为防治EC提供新的靶点。