细胞紧密连接调控的上皮通透性改变在确定口腔鳞状细胞鳞癌粘膜边界中的作用和机制

Vital staining is able to describe the mucosal margin of dysplastic/cancerous lesions on the upper digestive tract including the oral cavity during clinical examination and surgery with somewhat high false positive and negative staining results. Our previously published data and the resent results of pre-experiment suggested that the epithelial permeability might play a possible role in preventing the iodine stain from entering cells to define the mucosal margin of lesions. We speculate that the change of epithelial permeability may relate to carcinogenesis, grade of differentiation, tumor invasion and metastasis. Because the GSK3β-regulated cell tight junction (TJ) is the most important cell-cell junction type which is responsible for the epithelial permeability and GSK3β is also involved in multiple biological processes for example the normal cell proliferation, carcinogenesis and glucose metabolism, in this study, we attempt to compare and assess the TJ expressions and the iodine penetration depth in the mucosal margin areas of oral squamous cell carcinoma (OSCC) to identify the related TJ type (TJx) and to uncover the internal relations between the epithelial permeability and the histopathological characteristics. Subsequently, cultured OSCC cells with or without TJx expression and the normal basal cells from oral mucosa will be used to analyze how the TJx function in tumor invasion and metastasis and how the GSK3β regulate the integrity of cell tight junction. This study aims to clarify the molecular mechanism underlying the change of epithelial permeability during the multistage process of carcinogenesis in oral cavity and would help to make design of new vital staining agent for detecting OSCC.

肿瘤活体染色通过描绘上消化道异常粘膜边界以辅助检查或手术切除。较高的假阳性和假阴性率是其不足之处。我们前期研究和预实验结果表明，上皮通透状态影响碘染色剂进入细胞发挥作用，推测该通透性异常与肿瘤的发生、分化程度及侵袭转移有关。糖原合成酶激酶GSK3β调控的细胞紧密连接（Tight junction,TJ）是最重要的决定上皮通透性的细胞连接类型。因此本课题以细胞紧密连接为切入点，对比观察口腔鳞癌边界正常、异常上皮TJ蛋白表达和碘的渗透深度间的关系，鉴定与渗透相关的TJ蛋白（TJx）类型，揭示不同上皮通透状态与组织病理学表现之间的内在关联；培养TJx蛋白高、低表达肿瘤细胞和正常口腔粘膜基底细胞，分析TJx蛋白对癌细胞侵袭移动能力以及对癌上皮与正常上皮通透性的影响，以及 GSK3β对TJ完整性的调控机制。本研究旨在揭示上皮通透性改变在口腔鳞癌发展过程中的分子机制，为设计新型活体染色剂提供理论依据。