低剪应力诱导喉鳞癌细胞上皮-间质转化的分子机理研究

The epidemiological data show that Xinjiang Uyghur Autonomous Region of China is considered a high prevalence area of laryngeal squamous-cell carcinoma, and the morbidity and mortality rate are remarkably increaseded in the lately years. Nearly all laryngeal squamous-cell carcinoma deaths are a result of metastasis. Recent advances in laryngeal squamous-cell carcinoma therapeuties have led to improved survival in patients with metastatic tumor, however, prognosis is still poor for most patients. The switch of tumor cells from an epithelial to a mesenchymal-like phenotype [designated as epithelial-tomesenchymal transition (EMT)] is known to induce tumor cell motility and invasiveness, therefore promoting metastasis of solid carcinomas. EMT is regulated by both biochemical and physical signals from the microenvironment, including mechanical stress, which is increasingly recognized to play a major role in development and disease progression.Here we emphasize that induction of EMT in human carcinoma cells via a important biophysical inducer -low shear stress is associated with expression of multiple EMT related regulated molecules, chemokines and, in particular, with the induction of the IL-8/CXCR axis. Our previous study results showed low shear stress(0.14 Pa) could induce up-regulated expression of IL-8 and down-regulated expression of E-cadherin in laryngeal cancer cell line(Hep-2).Furthermore, the low E-cadherin/high IL-8 levels was associated with a relatively worse progress of patients with laryngeal squamous cell carcinoma performed with multivariate survival analyses. So our hypothesis in this study was that the local mechanical and biological factors could promote human laryngeal squamous cell carcinoma cells to EMT, especially low shear stress is an important induced factor in tumor cell motility and invasiveness, therefore promoting metastasis of solid carcinomas. We will utilize Tetracycline-regulated gene expression system for controlled wnt-1/β-catenin delivery, and employ a biomechanics flow chamber device mimicking in vivo microenviroment, to detailedly analyze the effect of biomechanics-coupled biological factors on the tumor cell motility and invasiveness of human laryngeal squamous cell carcinoma cell line Hep-2 in the context of EMT. Especially, we will investigate whether low shear stress-induced EMT drives wnt/β-catenin signaling pathway, then promot the secretion of a distinctive set of IL-8 by the tumor cells, and the potential role that IL-8/CXCR axis could play in the context of tumor cell motility and invasiveness.Our studies would contribute to reveal the cellular and molecular mechanism for low shear stress participating in the process of EMT so as to find new targets and measures for the disease control of metastasis of laryngeal squamous-cell carcinoma and to prevent or slow down the process of laryngeal squamous-cell carcinoma invasiiveness.

新疆是我国喉鳞癌高发地区, 喉鳞癌伴转移患者的发病率和死亡率呈逐年快速上升趋势。上皮-间质转化（EMT）是恶性肿瘤局部浸润和转移的重要机制。课题组在前期工作中发现：低剪切应力可下调喉鳞癌细胞E-cadherin表达，上调IL-8的表达；而EMT标志性蛋白E-cadherin低表达和IL-8高表达的喉鳞癌患者5年生存率明显减低；提示：低剪切应力可能是喉鳞癌获得EMT特性、继而迁移和侵袭的重要生物物理诱导因素。本项目拟进一步研究喉鳞癌细胞在低剪应力作用下表型转化与细胞迁移的细胞内信号转导规律，着重探讨"低剪应力→wnt/β-catenin信号转导→细胞获得EMT特性→IL-8及其受体CXCR上调→细胞迁移、侵袭↑"这条EMT分子信息传递的力学生物学机理，为喉鳞癌抗侵袭机制的研究以及选择有效的早期诊断、预防和抗喉鳞癌耐药治疗的分子靶点奠定基础。

新疆是我国喉鳞癌高发地区, 喉鳞癌伴转移患者的发病率和死亡率呈逐年快速上升趋势。上皮-间质转化（EMT）是恶性肿瘤局部浸润和转移的重要机制。课题组在前期工作中发现：低剪切应力可下调喉鳞癌细胞E-cadherin表达，上调IL-8的表达；而EMT标志性蛋白E-cadherin低表达和IL-8高表达的喉鳞癌患者5年生存率明显减低；提示：低剪切应力可能是喉鳞癌获得EMT特性、继而迁移和侵袭的重要生物物理诱导因素。本项目进一步利用基因调控表达技术、免疫共沉淀-质谱联用，在体外模拟流场模拟条件下，研究喉鳞癌细胞在低剪应力作用下表型转化与细胞迁移的细胞内信号转导规律。初步明确“低剪应力→wnt/β-catenin信号转导→细胞获得EMT特性→IL-8及其受体CXCR上调→细胞迁移、侵袭↑”这条喉鳞癌发生EMT的力学生物学分子信息传递机理，为喉鳞癌抗侵袭机制的研究以及选择有效的早期诊断、预防和抗喉鳞癌耐药治疗的分子靶点奠定基础。