HPV16调控HPV相关口咽癌病人放疗敏感性的分子机制研究

Recent studies have demonstrated that human papillomavirus (HPV)16 is highly related to oropharyngeal squamous cell carcinoma (OPSCC). The molecular profile of HPV-Associated oropharyngeal cancers with favorable prognosis, named HPV+/p16 high, has been defined. Our previous studies have shown HPV-Associated OPSCC patients are more sensitive to radiation therapy and expression of heat shock protein 70 kDa (HSP70) is increased after HPV16 is knocked-down. In this proposal, we hypothesize that expression level of HSP70 plays a key role in the response to radiation therapy for HPV-Associated OPSCC patients. We propose to detect the expression level of HPV16, p16 and HSP70 in OPSCC patients' tissue samples by using quatum-dots based immunohistofluorescence (IHF) technology, analyze the expression level of HSP70 among different subset of OPSCC patients, and determine correlation of HSP70 with prognosis of OPSCC patients. We will establish HPV16 overexpression OPSCC cell lines and HPV16 silence OPSCC cell lines, and detect the expression level of HSP70, HPV16 ,C23 cleavage and apoptosis in these cell lines after radiation treatment. We will also establish a HSP70 over expression cell line and an OPSCC xenograft model. This study will demonstrate the molecular mechanism underlying the HPV16 effect on radiation sensitivity in OPSCC patients and provide valuable information for treatment of the HPV-Associated OPSCC patients.

近年研究发现HPV16与口咽癌发病密切相关，并将HPV16+/p16+分子亚型的口咽癌命名为具有良好预后的HPV相关口咽癌。我们前期研究发现该类病人对放疗敏感性增加，靶向沉默HPV16后HSP70表达上调，因此，我们推测HSP70下调可能是该类病人对放疗敏感的重要因素。我们拟利用量子点平台检测口咽癌组织HPV16、p16和HSP70的表达，比较HSP70在不同亚型口咽癌中的表达差异及跟预后的关系；构建HPV16过表达及表达沉默的口咽癌细胞系，检测放疗后上述细胞中HPV16、HSP70、C23的断裂及细胞凋亡率等,从正反两方面观察HPV16对口咽癌细胞放疗敏感性的调控；构建HSP70过表达的口咽癌细胞系并建立口咽癌移植瘤模型，探讨HPV16通过下调HSP70增加口咽癌放疗敏感性的分子机制。本课题旨在阐明HPV相关口咽癌病人对放疗敏感的内在分子机制，为HPV相关口咽癌的临床治疗提供理论支撑。

本项目旨在阐明HPV相关口咽癌病人对放疗敏感的内在分子机制，为HPV相关口咽癌的临床治疗提供理论支撑。研究结果发现：1）p16蛋白表达和HPV16感染存在显著相关性，p16可能成为评估口咽鳞癌病人预后的重要指标；2）p16表达阴性的口咽癌组织中HSP70蛋白表达水平较高，主要分布在细胞浆，而在p16表达阳性的口咽癌组织中HSP70蛋白表达水平相对较低，主要分布在细胞膜；3）HPV16能够有效增加口咽癌细胞株对放疗的敏感性，且放疗增敏的细胞HSP70表达下调，而C23断裂增加。以上研究结果表明，HPV16+/p16+这一分子亚型中口咽癌病人对放疗敏感性增加的分子机制可能是HSP70表达下调，从而不能够修复放疗所致的核仁损伤；HSP70可通过调控口咽癌病人对放疗的敏感性直接影响口咽癌病人的预后；建立由HPV16、p16、HSP70三个分子生物标记物组成的多分子标记物平台可以更好地预测HPV相关口咽癌的预后。项目研究期间，申请人与项目组成员共发表相关学术论文4篇，其中SCI论文2篇，另有1篇英文论文正在投稿中（标注受本项目资助）。