ZNF326激活Wnt通路促进非小细胞肺癌恶性表型的分子机制

The incidence and mortality of lung cancer have ranked first among various malignant tumors, early diagnosis and prevention of recurrence and metastasis of lung cancer are key to reducing mortality. Abnormal activation of the Wnt pathway is closely related to the occurrence and progression of lung cancer, and the factors that activate the Wnt pathway are not fully understood. Previous studies by the applicant found that transfection of ZNF326 up-regulated HDAC7 and activated Wnt signaling, and knockdown of ZNF326 down-regulated Wnt signaling activity. In addition, HDAC7 can affect the activity of GSK-3β. However, the mechanism of ZNF326-HDAC7-GSK-3β is not clear. In view of this, the project using chromatin co-precipitation, gel migration, immunoblotting, and tumor formation in nude mice to clarify the molecular mechanism of ZNF326-HDAC7-GSK-3βinteraction by three parts: 1) HDAC7 is a target gene of ZNF326. 2) ZNF326 activates Wnt pathway via HDAC7. 3) HDAC7 promotes the accumulation of β-catenin in the cytoplasm by affecting GSK-3βacetylation and phosphorylation, which activates the Wnt signaling pathway. The implementation of this project provides a new experimental basis, possible targets and new ideas for the treatment of lung cancer.

肺癌的发病率及死亡率已位列恶性肿瘤之首，早期诊断和防止肺癌的复发和转移是降低死亡率的关键。Wnt通路的异常激活与肺癌的发生和进展密切相关，而激活Wnt通路的因子尚未完全清楚。我们前期研究发现ZNF326可上调HDAC7并激活Wnt通路，敲减ZNF326则Wnt信号活性下调。此外，HDAC7影响GSK-3β的活性。但ZNF326-HDAC7-GSK-3β具体作用机制不明确。鉴于此，本项目通过染色质共沉淀、凝胶迁移、免疫印迹和裸鼠成瘤等实验从以下3点来阐明三者之间的分子作用机制：1）HDAC7是ZNF326的靶基因。2）ZNF326通过HDAC7激活Wnt信号通路。3）HDAC7通过影响GSK-3β乙酰化和磷酸化，促使β-catenin在胞浆内积聚，入核激活Wnt信号通路。本项目的实施，为肺癌的治疗提供新的实验依据、可能的靶点和新的思路。

摘要：锌指蛋白326(ZNF326)与肺癌的发生发展密切相关，在前期研究中发现ZNF326在肺癌中高表达，并可正向调控去乙酰化蛋白酶7(HDAC7)蛋白的表达，但其具体作用机制尚不清楚。我们通过免疫组化检测ZNF326及HDAC7在非小细胞肺癌中高表达，与非小细胞肺癌的高分期相关，两者呈正相关。并通过染色质共沉淀及双荧光素酶报告基因证实HDAC7是ZNF326的靶基因。在体内外实验中，通过双向调控ZNF326及HDAC7的蛋白及RNA水平，发现ZNF326可通过正向调控HDAC7的mRNA及蛋白水平，降低糖原合成酶激酶3β(GSK3β)蛋白的磷酸化水平，影响B-catenin的表达及定位，激活Wnt信号通络，从而促进非小细胞肺癌的恶性转化。本研究揭示了ZNF326-HDAC7- GSK3-β在非小细胞肺癌恶性发展中的重要作用和机制，为寻找非小细胞肺癌的生物标志物和治疗靶点提供参考。