放疗是喉癌的重要治疗手段，其疗效不佳主要与喉癌细胞放射抗拒有关，克服放射抗拒前提是揭示其分子机制。我们前期发现脂筏相关蛋白PAG1介导喉癌原发性放射抗拒，但机理不明。研究表明过表达PAG1可增强整合素β1活性，而我们证实原发性放射抗拒喉癌细胞中整合素β1是PAG1的潜在结合蛋白，故推测PAG1通过调控整合素β1在脂筏内活化从而介导喉癌原发性放射抗拒。本课题拟首先采用喉癌临床标本分析PAG1、活化型整合素β1的表达与喉癌患者放疗敏感性关系；进而在体内外通过基因转染和CRISPR/Cas9技术干预PAG1表达，检测喉癌放射抗拒性状改变、整合素β1的活化状态及定位，明确PAG1对整合素β1活化的调控作用；并采用胆固醇缺失、截短突变、GST pull down解析PAG1与整合素β1的相互作用模式。本研究内容将阐明PAG1介导喉癌原发性放射抗拒的分子机制，并为克服喉癌放射抗拒提供可靠的干预靶点。

Radiotherapy is an important treatment for laryngeal carcinoma, and its poor curative effects are mainly associated with radioresistance of laryngeal carcinoma cells. The premise of overcoming radioresistance is based on the fact that the molecular mechanism of radioresistance has been revealed. In our previous study, we found that lipid raft-associated protein PAG1 could mediate inherent radioresistance of laryngeal carcinoma, but its mechanism was unknown. It has been reported that the up-regulated expression of PAG1 was able to increase integrin β1 activity. We also confirmed that integrin β1 was a potential combination protein of PAG1 in the inherent radioresistance of laryngeal carcinoma cells. Accordingly, we thought that PAG1 could induce the activation of integrin β1 in lipid rafts so as to regulate the inherent radioresistance of laryngeal carcinoma. In this study, the laryngeal carcinoma clinical tissues were used to investigate the relationship between the expression levels of PAG1 and activated integrin β1 and the radiosensitivity of laryngeal carcinoma patients. Furthermore, the expression of PAG1 was interfered by gene transfection and CRISPR/Cas9 technique in vivo and in vitro. Then the change in the radioresistant property of laryngeal carcinoma, the activation and location of integrin β1 was detected to identify the regulation effect of PAG1 on integrin β1 activation. In addition, lack of cholesterol, truncated mutations and GST pull down assays were carried out to parse the interaction pattern of PAG1 and integrin β1.The results of this study not only clarify the molecular mechanism of PAG1-mediated inherent radioresistance in laryngeal carcinoma, but also provide a reliable intervention target to overcome the radioresistance of laryngeal carcinoma.