HPV-16癌蛋白对肺癌细胞上皮-间质转化的影响及其分子机制

In our previous studies supported by the National Natural Science Foundation of China (NSFC，No.30872944), we have demonstrated for the first time to our knowledge that HPV-16 oncoproteins enhanced the expression of HIF-1α, IL-8, and FGF-2 proteins and the increased IL-8 expression induced by HPV-16 oncoproteins was HIF-1α-dependent. Several lines of evidence have shown that HIF-1α, IL-8, and FGF-2 have the potential to promote epithelial-mesenchymal transition (EMT) in cancer cells. In this proposal, we will adopt both in vitro and in vivo approaches, including analysis of clinical tumor samples from lung cancer patients, to further explore the effects of HPV-16 oncoproteins on EMT in human lung cancer cells and the underlying molecular mechanisms. Specifically, we will explore: 1) effects of HPV-16 oncoproteins on morphological alteration, migration, invasion, the synthesis and degradation of extracellular matrix (ECM), and the expression of EMT-related markers in human lung cancer cells; 2) the role of HIF-1α/IL-8 or FGF-2 axis in HPV-16 oncoprotein-mediated regulation of the expression of new transcriptional factors (Twist 1 and Slug) and EMT-related markers in human lung cancer cells; 3) the contribution of PI3K/Akt signaling pathway to HPV-16 oncoprotein-mediated EMT in human lung cancer cells. The completion of this project will contribute to a more comprehensive recognition of the important role of HPV-16 oncoproteins in the development and progression of non-smoking-associated lung cancer in a new angle, and lead to the identification of novel molecular targets for the prevention and treatment of HPV-related lung cancer.

在已结题的NSFC项目（30872944）资助下，我们首次发现HPV-16癌蛋白可增强肺癌细胞HIF-1α、IL-8、FGF-2蛋白表达，IL-8表达的增强还具有HIF-1α依赖性。因近年报道HIF-1α、IL-8、FGF-2可促进肿瘤细胞上皮-间质转化(EMT），故本项目拟在我们的前期研究基础上，通过细胞实验、动物实验和临床肺癌组织标本分析，探讨HPV-16癌蛋白对肺癌细胞EMT的影响及其分子机制。主要观察HPV-16癌蛋白对肺癌细胞形态、迁移、侵袭、细胞外基质合成和降解、相关EMT标志物表达的影响，重点探讨HIF-1α/IL-8或FGF-2轴、新的转录因子（Twist 1、Slug）在HPV-16癌蛋白对肺癌细胞EMT影响中的作用及PI3K/Akt信号途径的调控机制。本项目的完成可从新的角度揭示HPV-16癌蛋白在非吸烟相关肺癌发展中的作用，为HPV感染相关肺癌的防治提供新的分子靶点。

高危型人乳头瘤病毒（human papillomavirus，HPV）-16感染可能与非吸烟相关肺癌的发展有关，而上皮-间质转化（epithelial-mesenchymal transition，EMT）在肺癌发展中起重要作用。本项目通过细胞实验、动物实验和临床肺癌组织标本分析，探讨HPV-16癌蛋白对肺癌细胞EMT的影响及其分子机制。结果发现，HPV-16 E6和E7癌蛋白可明显增强肺癌细胞A549和NCI-H460的迁移、侵袭能力，降低肺癌细胞EMT上皮标志物E-cadherin和ZO-1的表达，促进EMT间质标志物N-cadherin和Vimentin的表达，并显著上调EMT相关转录因子ZEB1、Snail1、Slug和Twist1的表达，这些结果说明HPV-16 E6和E7癌蛋白可通过促进肺癌细胞EMT增强其迁移、侵袭能力。进一步的机制研究还发现，HPV-16 E6和E7癌蛋白诱导的肺癌细胞EMT具有低氧诱导因子-1α (hypoxia inducible factor-1α，HIF-1α)依赖性，PI3K/Akt信号转导途径可能参与调控HPV-16 E6和E7癌蛋白诱导的肺癌细胞EMT， STAT3信号转导途径可能参与调控HPV-16 E6癌蛋白诱导的肺癌细胞EMT。这些研究成果不仅可从EMT这个新的角度揭示HPV-16癌蛋白在非吸烟相关肺癌发展中的作用，而且还进一步证实HIF-1α可能为HPV相关肺癌防治的潜在靶点。