Global Hypomethylation Biomarkers for Cervical Cancer Screening in Women Living with HIV in LMICs

项目摘要 宫颈癌（CC）是中低收入国家（LMIC）最常见的癌症之一。 由于艾滋病毒感染率很高， 某些非洲国家，如尼日利亚和坦桑尼亚。有效的筛查和早期发现是 预防CC的关键然而，在中低收入国家，多次巴氏涂片筛查仍然费用高昂， 在低收入国家中，有患CC风险的妇女，特别是感染艾滋病毒的妇女，较少受到CC预防战略的覆盖 妇女一种替代的简单，负担得起的，非侵入性CC第一线筛查工具，用于HIV相关CC 艾滋病毒流行率高的低收入国家迫切需要这种方法。 HIV感染促进宫颈癌发生的分子变化在很大程度上仍不清楚。 表观遗传畸变，特别是重复元件（RE）中的整体DNA甲基化（DNAm）丢失 区域，已被认为是人类癌症的标志。RE是DNA序列， 在整个基因组中有多个拷贝如果RE被激活（例如，通过HIV感染）， 在新的基因组位置复制并重新插入人类DNA，导致基因组不稳定 和可能导致癌症的体细胞突变。这些RE中的DNAm是一种保护机制， RE来自易位，并且在肿瘤发生的早期阶段已经观察到其丢失。 具体来说，艾滋病毒感染已被证明会降低全球DNA水平并重新激活RE易位 活动因此，我们假设HIV感染可能通过引起全球性的炎症反应来促进CC的发展。 RE的去甲基化和这种表观遗传学变化在自我收集的宫颈上皮内瘤变中的作用 (CIN)样本可以预测进展为侵袭性CC。 我们提出了两个研究目标。在目标1中，我们将识别和验证HIV相关CC全局RE DNAm 生物标志物。我们将利用我们正在进行的U 54 CC表观基因组项目的现有DNAm数据， 尼日利亚（U 54 CA 221205，PI：Hou/Murphy）生成全球RE DNAm数据，用于生物标志物开发 使用我们新颖的生物信息学方法。然后，我们将通过实施 在LMIC实验室中建立一个经济实惠、靶向和定量的基于PCR的DNA平台。在目标2中，使用 使用相同的基于PCR的方法，我们将测试目标1中验证的生物标志物是否可以预测CC的风险 进展我们将利用来自艾滋病毒阳性妇女纵向队列的两组样本， 患有低度CIN的患者：a）来自我们U 54队列的尼日利亚巴氏涂片样本;和B）坦桑尼亚 来自独立U 54队列的宫颈阴道拭子样本（U 54 CA 190155，PI：Wood/Soliman）。 在坦桑尼亚队列中，在可自行采集的宫颈阴道拭子中测试我们的生物标志物， 其在LMIC环境中的可行性和临床相关性。如果成功，我们的研究可能有助于开发新的 今后可能为中低收入国家感染艾滋病毒的妇女提供CC筛查和早期检测工具。

Project Summary Cervicalcancer (CC) is one of the most common cancers in low and middle-income countries (LMICs). This situation is worsened by a high prevalence of human immunodeficiency virus (HIV) infection in certain African countries, such as Nigeria and Tanzania. Effective screening and early detection is the key to preventing CC. However, multiple Pap smear visits for screening test remains costly in LMICs and coverage of CC preventive strategy reach fewer women at risk of CC in LMICs, in particular HIV-infected women. An alternative easy, affordable, non-invasive CC front-line screening tool for HIV-associated CC is urgently needed in LMICs with high HIV prevalence. The molecular changes by which HIV infection promotes cervical carcinogenesis remain largely unknown. Epigenetic aberrations, especially global DNA methylation (DNAm) loss in repetitive element (RE) regions, have been recognized as a hallmark of human cancers. REs are DNA sequences that occur in multiple copies throughout the genome. If REs are activated (for example, by HIV infection) they can multiply and reinsert themselves into human DNA at new genomic locations, leading to genomic instability and somatic mutations that may cause cancer. DNAm in these REs is a protective mechanism to stabilize RE from translocation, and its loss has been observed seen in the early phase of tumorigenesis. Specifically, HIV infection has been shown to reduce global DNAm level and reactivate RE translocation activity. We thus hypothesize that HIV infection may promote CC development via causing global demethylation of RE and that such epigenetic changes in self-collected cervical intraepithelial neoplasia (CIN) samples may predict progression into invasive CC. We propose two study aims. In Aim 1, we will identify and validate HIV-associated CC global RE DNAm biomarkers. We will utilize the existing DNAm data from our ongoing U54 CC epigenomic project in Nigeria (U54CA221205, PI: Hou/Murphy) to generate global RE DNAm data for biomarker development using our novel bioinformatics methods. We will then validate the biomarkers by implementing an affordable, targeted, and quantitative PCR-based DNAm platform in a LMIC laboratory. In Aim 2, using the same PCR-based approach, we will test if the biomarkers validated in Aim 1 can predict risk of CC progression. We will leverage two groups of samples from longitudinal cohorts of HIV-positive women who had low-grade CIN: a) Nigeria Pap smear samples from our U54 cohort; and b) Tanzania cervicovaginal swab samples from an independent U54 cohort (U54CA190155, PI: Wood/Soliman). Testing our biomarkers in self-collectable cervicovaginal swabs in our Tanzania cohort allows us to test their feasibility and clinical relevance in LMIC settings. If successful, our study may help develop new possible future CC screening and early detection tools for women living with HIV in LMICs.