XVII型胶原蛋白通过上皮间质转化在促进皮肤鳞癌侵袭和转移中的分子机制的研究

Squamous-cell carcinomas (SCCs) has been suggested to be is the second most common cancer overall among the skin cancer patients. And these SCCs are also very aggressive and invasive.Although most cutaneous squamous cell carcinoma is curable, 4% result in nodal metastasis and 1.5% in death. Squamous cell carcinoma on head and neck is associated with severe disease- and treatment-related morbidity and has a 5-year survival rate of approximately 50%, mainly due to the strong invasive capacity. Recent studies have advanced our understanding of the molecular mechanisms of the disease.In Previous Studies, we found VII collagen, an adhension molecule,prevented the motlity and invasion,closely related the SCCs.In addition, No reports demonstrated the founctions of XVII collagen(COL17),the same adhension molecule.We recently demonstrated that collagen XVII enhances keratinocyte adhesion to collagen IV, and in P38-MAPK-dependent migration and cell signaling.From these results and references, we hypothesis COL17 have the important role at the dynamically continuous processing of the SCCs molity and invasion.These provide an important experment basis,COL17 expression and the development of SCCs stage is a supplement each other influence factors. In this studies, we use the SCCs cell lines and animal models for analyzing the relationship the expression of COL17 with the molity and invasion. Further sutdies should be checked the precautionary effect of COL17 to SCCs,a high risk of developing and malignant in the patients of epidermolysis bullsosa. The anticipated results will lay a solid foundation for comprehensively clarifying the mechanism underlying promotion of Col17 on the cell invasion of squamous cell carcinoma, and will be helpful for further understanding of function of COL17 and mechanism of cell invasion regulated it, will provide new strategy and new target for the treatment of squamous cell carcinoma.

侵袭性极强的头颈部鳞癌五年生存率仅为50%。有关鳞癌侵袭、转移的研究一直是皮肤科学界关注的重点领域之一，但机制尚未明确。我们的前期研究表明位于皮肤基底膜带的XVII型胶原蛋白（COL17）可调控角质形成细胞的迁移；COL17在癌前病变中低表达，而鳞癌高表达，且与鳞癌分化负相关；细胞划痕及transwell实验发现COL17可明显促进鳞癌细胞的侵袭，并显著的观察到了EMT即上皮间质转化的发生，及E、N-钙粘蛋白表达量的转化。但COL17促进鳞癌细胞侵袭的机制尚不清楚。本项目拟以鳞癌为研究对象，从临床标本、细胞水平和动物实验三方面，验证COL17的表达与皮肤鳞癌的侵袭和转移的相关性，阐明COL17通过与整合素（integrin）的结合，和下游激酶通路的激活，促进皮肤鳞癌侵袭和转移的分子机制，探讨COL17表达在预防或抑制鳞癌侵袭转移的作用，为皮肤鳞癌的综合治疗提供新策略。

侵袭性极强的头颈部鳞癌五年生存率仅为50%。有关鳞癌侵袭、转移的研究一直是皮肤科学界关注的重点领域之一，但机制尚未明确。我们的前期研究表明位于皮肤基底膜带的XVII型胶原蛋白（COL17）可调控角质形成细胞的迁移；COL17在癌前病变中低表达，而鳞癌高表达，且与鳞癌分化负相关；细胞划痕及transwell实验发现COL17可明显促进鳞癌细胞的侵袭，并显著的观察到了EMT即上皮间质转化的发生，及E、N-钙粘蛋白表达量的转化。但COL17促进鳞癌细胞侵袭的机制尚不清楚。.本课题明确XVII collagen的表达水平是否与肿瘤形成及转移存在相关性：把SCC细胞株及所建立的不同表达水平的XVII collagen knockdown细胞系，和SCC原生代细胞系移植到裸鼠的皮下，利用near-infrared light-emitting观察生存状态的裸鼠的肿瘤的形成速度，大小等。同时，比较所形成的肿瘤在大小，转移等方面的数据。发现，XVII collagen的高表达肿瘤的形成速度，大小呈正相关。分析肿瘤的恶化对XVII Collagen的表达的影响：涂抹DMBA,TPA的化学手段，或者UVB的照射来诱导老鼠的皮肤癌的发生。在起始XVII collagen表达量固定的基础上，利用GeneChip，RT-PCR，western blotting，病理切片等方法来检测不同时间段的XVII collagen表达量的变化，通过对裸鼠移植不同表达量的SCC细胞株来分析成瘤能力，侵袭能力等方面的数据。发现XVII collagen的高表达的细胞的成瘤能力，侵袭能力明显高于低表达的细胞株。XVII Collagen敲除裸鼠及裸鼠等不同实验系的利用，分析了肿瘤的形成过程，分析了肿瘤形成对XVII Collagen的表达的影响。确定COL17的高表达促进了皮肤癌的发生，侵袭和转移的机制：通过体内及体外研究，利用western blot及RT-PCR等手段对SCC细胞系进行分析，阐明了COL17通过与整合素（integrin）的结合，进一步对下游激酶通路的激活，明确了通过其调控或结合laminin-5, 和α6β4 integrin促进皮肤鳞癌侵袭和转移的分子机制，为皮肤鳞癌的综合治疗提供了新策略。