Department of Respiratory and Critical Care Medicine, Qilu Hospital of Shandong University, Jinan 250012, China.
Department of Respiratory Medicine, First Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China.
EBioMedicine. 2019 Aug;46:42-53. doi: 10.1016/j.ebiom.2019.07.071. Epub 2019 Aug 6.
Twist-related protein 1 (TWIST1) plays an essential role in the carcinogenesis and metastasis of NSCLC. Our aims were to identify the molecule at the downstream of TWIST1 and to evaluate its potential as a diagnostic and a prognostic marker in NSCLC.
The functional genes at the downstream of TWIST1 were obtained via microarray gene expression analyses in the NSCLC cell line. The expression levels of synaptotagmin 7 (SYT7) in a cohort of patients with NSCLC (n = 154) were examined using immunohistochemistry staining and assessed by Kaplan-Meier survival analysis and Cox regression analysis. The effects of SYT7 on the tumorigenesis and metastasis of NSCLC were measured in NSCLC cells. In vivo xenograft lung cancer models were used to study the tumorigenesis role of SYT7.
We discovered that SYT7 is significantly altered by TWIST1 expression. We further confirmed that SYT7 protein was significantly higher in NSCLC than that in the adjacent normal lung tissue, and higher SYT7 expression was associated with poor survival of NSCLC patients. The protein level of SYT7 was positively correlated with TWIST1 in NSCLC tissue. Functional experiments indicated that SYT7 promoted proliferation, invasion, and metastasis and inhibited cell apoptosis of NSCLC cells in vitro. In vivo experiments showed that shSYT7 inhibited the xenograft tumor growth of NSCLC cells. Knocking down of SYT7 increased the expression of E-cadherin and decreased the level of N-cadherin and Vimentin in cultured cells.
Our data indicate that SYT7 is an important promoter for EMT and tumor progression in NSCLC. FUND: This project was supported by grants from the Major Scientific and Technological Innovation Project of Shandong Province (2018CXGC1212), Science and Technology Foundation of Shandong Province (2014GSF118084, 2016GSF121043), Medical and Health Technology Innovation Plan of Jinan City (201805002) and the National Natural Science Foundation of China (81372333).
TWIST 相关蛋白 1（TWIST1）在非小细胞肺癌的发生和转移中起着重要作用。我们的目的是鉴定 TWIST1 下游的分子，并评估其作为非小细胞肺癌诊断和预后标志物的潜力。
通过 NSCLC 细胞系的微阵列基因表达分析获得 TWIST1 下游的功能基因。采用免疫组织化学染色法检测 SYT7 在 154 例 NSCLC 患者中的表达水平，并通过 Kaplan-Meier 生存分析和 Cox 回归分析进行评估。采用 SYT7 在 NSCLC 细胞中的肿瘤发生和转移进行检测。体内异种移植肺癌模型用于研究 SYT7 的肿瘤发生作用。
我们发现 SYT7 明显受 TWIST1 表达的影响。我们进一步证实，SYT7 蛋白在 NSCLC 中明显高于相邻正常肺组织，并且较高的 SYT7 表达与 NSCLC 患者的不良预后相关。SYT7 蛋白水平与 NSCLC 组织中的 TWIST1 呈正相关。功能实验表明，SYT7 促进了 NSCLC 细胞的体外增殖、侵袭和转移，并抑制了细胞凋亡。体内实验表明，shSYT7 抑制了 NSCLC 细胞的异种移植肿瘤生长。敲低 SYT7 增加了培养细胞中 E-钙粘蛋白的表达，降低了 N-钙粘蛋白和波形蛋白的水平。
我们的数据表明，SYT7 是 NSCLC 中 EMT 和肿瘤进展的重要促进因子。
本项目得到山东省重大科技创新项目（2018CXGC1212）、山东省科技发展计划（2014GSF118084、2016GSF121043）、济南市医疗卫生科技计划（201805002）和国家自然科学基金（81372333）的资助。
