VIROLOGIC/GENETIC FACTORS OF HPV NEOPLASMS

该项目的总体目标是确定表达人乳头状瘤病毒(HPV)基因的人类细胞的遗传和表观遗传学变化，特别是表达HPV16和18的E6/E7癌基因的细胞。推动这些研究的基本假设是，尽管HPV癌基因表达启动并维持异常的细胞复制，通过与P53和视网膜母细胞瘤(RB)基因产物相互作用，但由于遗传不稳定，宿主细胞基因表达的后续变化导致侵袭性癌的进展。结合项目1中的人口研究，我们将在与原发和继发肛门肿瘤相关的病毒学和遗传因素的背景下测试这一假说。对同一个体多个肿瘤中病毒整合位点的研究，旨在确定整合的HPV DNA两侧的细胞序列，将为多个肿瘤的独立起源提供重要证据。我们将把我们目前对宫颈染色体变化的CGF研究扩展到其他肛门生殖肿瘤和患有多发性肛门生殖道癌的个体组织。这项分析将确定初始肿瘤和后续肿瘤在相同或不同肛门生殖器部位的任何共同区域。结果将与该计划其他项目中确定的其他风险因素，如吸烟、家族史、性传播疾病等的关系进行检查。我们将使用阵列方法来识别促进肿瘤进展的基因，例如作为潜在的肿瘤抑制基因。最初，我们将这些实验限制在染色体#3、#5和#20的区域，因为这些区域已经被USE和其他经常显示在宫颈癌中丢失或获得的区域所识别。高危病毒的E6癌基因可以诱导端粒酶的发现表明，这一特性可能有助于HPV感染的宫颈和其他上皮细胞的恶变。原代人类上皮细胞对E6的反应，就端粒酶诱导水平而言，已被证明是不同的。我们将使用一个模型系统来研究这些可变反应的程度是否可以用作潜在进展的标志。

The overall aim of this project is the identification of genetic and epigenetic changes in human cells expressing human papillomaviruses (HPV) genes, with particular reference to cells expressing the E6/E7 oncogenes of HPV 16 and 18. The underlying hypothesis driving these studies is that while HPV oncogene expression initiates and maintains abnormal cell replication, by interacting with the p53 and retinoblastoma (Rb) gene products, subsequent changes in host cell gene expression, as a consequence of genetic instability, result in progression to invasive carcinoma. In conjunction with the population studies in Project #1, we will test this hypothesis in the context of virologic and genetic factors associated with primary and secondary anogenital tumors. A study of the viral integration sites in multiple tumors from the same individual, aimed at identification of the cellular sequences flanking integrated HPV DNA, will provide significant evidence for the independent origin of relatedness of multiple tumors. We will extend our current CGF studies of chromosomal changes in cervical to other anogenital tumors and to tissues from individual with multiple anogenital cancers. This analysis will identify any regions common to an initial tumor and subsequent tumors at the same or different anogenital sites. The results will be examined for relationship to other risk factors, e.g. smoking, family history, sexually transmitted disease, etc., identified in other projects in the program. We will use array methods to identify genes contributing to tumor progression, for example as potential tumor suppressor genes. Initially we will restrict these experiments to regions of chromosomes #3, #5 and #20, because these have been identified by use and others as frequently showing loss or gain in cervical carcinoma. The finding that the E6 oncogene of the high-risk viruses can induce telomerase suggest that this property could contribute to the progress of HPV-infected cervical and other epithelial cells to malignancy. The response of primary human epithelial cells to E6, in terms of the level of telomerase induction, has been shown to be variable. We will use a model system to investigate whether the extent of these variable response can be utilized as a marker of potential progression.