Cervical Cancer Preventive Measures Based on HPV 16 Epigenome

描述（由申请人提供）：HPV 16发挥致癌作用的主要机制是通过两个病毒早期基因E6和E7的表达。因此，调控E6和E7表达的因子可能影响HPV 16感染向更高级别宫颈上皮内瘤变（CIN 2+）或侵袭性宫颈癌（ICC）的转化。HPV 16 DNA甲基化（DNAm）的程度已被证明影响其基因表达、病毒生命周期、持久性和复制行为。我们最近的研究表明：1)在宫颈脱落细胞（ECs）中检测较高程度的HPV 16 DNAm与诊断CIN 2+的可能性降低79%相关2)与任何致癌HPV类型检测阳性或pap异常检测阳性的女性相比，HPV 16 DNAm的程度显示出最好的阳性预测值（PPV），用于识别CIN 2+的女性。3)叶酸循环浓度较低的HPV 16阳性妇女被诊断为CIN 2+的可能性是叶酸浓度较高的HPV 16阴性妇女的9倍。由于HPV使用人类甲基化机制来制造其DNAm，因此影响人类细胞中DNAm的相同因素，即叶酸代谢途径产生的甲基的可用性，也可能具有改变HPV 16 DNAm程度的能力。在此背景下，本研究的目的如下：目的1。为了评估HPV 16 DNAm与CIN之间的关系，使用从我们发表的研究中确定的ECs配对样本和宫颈活检中提取的DNA （HPV 16 E6增强子的7862位和HPV 16 E6启动子的31、37、43、52和58位）和CIN 2+，以便在一个单独的、更大的女性群体中复制我们的发现。这一目标将在已经从300名诊断为CIN 2+（病例）的妇女和300名诊断为CIN 1（非病例）的妇女中收集的样本中进行测试。评估目的1相同部位的HPV 16脱氧核糖核酸水平与叶酸循环浓度之间的关系，以评估由于美国叶酸强化计划而暴露于不同水平的叶酸的影响。这一目标将在已经从300名诊断为CIN的妇女中收集的样本中进行测试。该研究将提供一个独特的机会，以确定检测HPV 16 dna nam的程度，以确定发生HPV 16相关CIN 2+的高风险妇女的诊断价值。此外，该研究整合了一个重要的人群环境暴露（叶酸）和分子数据，通过测试叶酸暴露可能有能力改变HPV 16 dna nam的程度，并改变HPV 16相关的风险，在美国后叶酸强化时代发生CIN。

DESCRIPTION (provided by applicant): A main mechanism by which HPV 16 exerts oncogenic effects is through the expression of two viral early genes, E6 and E7. Therefore, factors that regulate the expression of E6 and E7 are likely to influence transformation of HPV 16 infections to higher grades of cervical intraepithelial neoplasia (CIN 2+) or invasive cervical cancer (ICC). The degree of HPV 16 DNA methylation (DNAm) has been shown to influence its gene expression, viral life cycle, persistence and replicative behavior. Our recent studies demonstrated the following: 1) A higher degree of HPV 16 DNAm assayed in exfoliated cells (ECs) from the cervix was associated with 79% reduced likelihood of being diagnosed with CIN 2+ 2) The degree of HPV 16 DNAm showed the best positive predictive value (PPV) for identifying women with CIN 2+, compared to women tested positive for any carcinogenic HPV type or tested positive for abnormal pap, two tests commonly used by Health Departments to identify high risk women 3) HPV 16-positive women with lower circulating concentrations of folate were nine times more likely to be diagnosed with CIN 2+ compared to HPV 16-negative women with higher folate. Because HPV uses the human methylation machinery for its DNAm, the same factors which influence DNAm in human cells, namely the availability of methyl groups generated by the folate metabolic pathway, may also have the ability to alter the degree of HPV 16 DNAm. With this background, the aims of the study are as follows: Aim 1. To evaluate the association between the degree of HPV 16 DNAm and CIN using DNA extracted from paired samples of ECs and cervical biopsies at sites identified in our published study (position 7862 of the HPV 16 E6 enhancer and positions 31, 37, 43, 52 and 58 of the HPV 16 E6 promoter) and CIN 2+, in order to replicate our findings in a separate, larger group of women. This aim will be tested among samples already collected from 300 women diagnosed with CIN 2+ (cases) and 300 women diagnosed with d CIN 1 (non-cases) Aim 2. To evaluate the association between the degree of HPV 16 DNAm at the same sites as in aim 1 and circulating concentrations of folate, in order to assess the influence of exposure to different levels of folate as a result of the US folic acid fortification program. This aim will be tested among samples already collected from 300 women diagnosed with d CIN 1. The study will provide a unique opportunity to determine the diagnostic value of testing the degree of HPV 16 DNAm for identifying women at high risk for developing HPV 16 associated CIN 2+. Further, the study integrates an important population-wide environmental exposure (folate) and molecular data by testing the hypothesis that exposure to folate may have the ability to alter the degree of HPV 16 DNAm and modify the HPV 16 associated risk of developing CIN in the US post-folic acid fortification era.