已有报道及我们的前期研究揭示HPV16 E6/E7与DNA甲基化及组蛋白甲基化和乙酰化相关，但其影响程度及作用机理尚未得到系统阐明。我们推测E6/E7可能与相关蛋白酶发生直接或间接的作用导致这些表观遗传现象的发生，进而影响目的基因表达和功能的变化。本研究拟通过，(1) E6/E7基因沉默、 (2)E6/E7转染及再沉默的手段，研究沉默前、后、转染及再沉默前、后目的基因DNA甲基化水平、组蛋白甲基化和乙酰化水平、相关蛋白酶活性和蛋白表达水平、及致瘤能力的变化；和通过(3) 免疫共沉淀和GST-pulldown技术，在胞内外分别进行E6/E7蛋白与相关蛋白酶之间相互作用的机理研究。本项目将为进一步阐明HPV16通过DNA甲基化及组蛋白甲基化和乙酰化途径的致癌机理提供有力的理论依据。

Published data and our preliminary study suggest that HPV16 E6/E7 proteins directly influence epigenetic changes to host genes, including DNA methylation, histone methylation and acetylation. However, its degree of influence and mechanism of action has not been systematically investigated. We hypothesize that E6/E7 can directly or indirectly act on epigenetic modifying enzymes leading to epigenetic alterations, thereby affecting expression and function of the target genes. In order to test our hypothesis, E6/E7 gene silencing (knockdown)，E6/E7 gene overexpression and re-silencing (re-knockdown) will be explored to investigate the subsequent impact on change patterns of DNA methylation, histone methylation and acetylation, as well as epigenetic modifying enzymes, protein expression, and tumorigenicity in animal model. In addition, the interaction between E6/E7 protein and epigenetic modifying enzymes will be in vivo and in vitro investigated by Co-immunoprecipitation and GST-pulldown technologies. The proposed project will further elucidate the potential carcinogenic mechanism of HPV16 through influencing DNA methylation, histone methylation and acetylation pathway.