GENETIC MECHANISM OF BRCA LINKED OVARIAN TUMORIGENESIS

描述：(改编自调查人员的摘要)大约10 所有卵巢癌的百分比与常染色体显性遗传有关 易感。现在公认的是，这些人中的绝大多数 遗传性卵巢癌可归因于 最近克隆并鉴定了肿瘤抑制基因BRCA1或BRCA2。这个 这个项目的长期目标是确定分子遗传 BRCA相关卵巢癌的发生机制及定义 这些癌症的临床和生物学特征。具体地说，这个项目 将聚焦于两个主要目标，第一个目标是检验以下假设 BRCA杂合子的病理正常卵巢组织显示 临床前组织学、分子遗传学和细胞生物学改变。 对患有有害生殖系BRCA的妇女预防性摘除卵巢 基因突变将与风险不高的女性的基因突变进行比较 关于卵巢癌的组织学特征的流行率 可能代表癌前病变，而增殖与 凋亡的上皮细胞。结合使用显微解剖，基于聚合酶链式反应 BRCA卵巢的DNA分析和免疫组织化学技术 野生型BRCA的区域丢失将进一步分析杂合子 等位基因和TP53突变，这些事件发生的顺序，以及 这些事件与异常组织学变异区域的相关性。它 预计这些研究将有助于更好地理解 遗传性卵巢肿瘤发生的早期分子遗传学事件 具体地说，并更深入地了解 一般都是卵巢癌。这些信息应该会在 开发早期发现卵巢癌的新方法。这个 第二个主要目的是解决BRCA蛋白在体内发挥作用的假设 细胞对治疗性DNA损伤剂(化学和 物理)，并进一步确定该功能是否特定于 特定类型的DNA损伤(例如，双链DNA断裂)。这一目标将 通过检测BRCA表达对细胞的影响来实现 对几种不同类别的细胞毒性化疗药物的反应和 辐射，使用三种实验策略进行比较 表达BRCA和不表达BRCA的细胞：1)在 BRCA缺陷型人肿瘤细胞株；2)BRCA缺陷型的直接比较 和BRCA-野生型肿瘤细胞系，以及；3)反义介导的BRCA缺失 在BRCA-野生型肿瘤细胞系中。这些研究的数据可能会导致 开发更有效的治疗策略来治疗遗传性疾病 卵巢癌患者的亚群。

DESCRIPTION: (Adapted from the investigator's abstract) Approximately 10 percent of all ovarian cancers are associated with autosomal dominant genetic predispostion. It is now well established that the great majority of these hereditary ovarian cancers are attributable to inherited mutations in the recently cloned and characterized tumor suppressor genes BRCA1 or BRCA2. The long-term goals of this project are to determine the molecular genetic mechanism through which BRCA-linked ovarian cancers develop and to define the clinical and biological features of these cancers. Specifically, this project will focus on two major aims, the first of which is to test the hypothesis that pathologically normal ovarian tissues from BRCA heterozygotes exhibit preclinical histologic, molecular genetic, and cell biological alterations. Ovaries removed prophylactically from women with deleterious germline BRCA mutations will be compared to those removed from women not at increased risk for ovarian cancer with regard to the prevalence of histological features that may represent premalignant alterations, and the ratio of proliferating to apoptotic epithelial cells. Using a combination of microdissection, PCR-based DNA analyses, and immunohistochemical techniques, ovaries from BRCA heterozygotes will be further analyzed for regional loss of the wild-type BRCA allele and TP53 mutation, the order in which these events occur, and the correlation of these events with regions of abnormal histologic variation. It is anticipated that these studies will lead to an improved understanding of the early molecular genetic events in heretidary ovarian tumorigenesis specifically, and to greater insight into the cell or region of origin of ovarian carcinoma generally. This information should prove useful in the development of new approaches for the early detection of ovarian cancer. The second major aim is to address the hypothesis that BRCA proteins function in the cellular response to therapeutic DNA damaging agents (chemical and physical), and further, to determine whether this function is specific for a particular type of DNA damage (e.g., double-strand DNA breaks). This aim will be accomplished by examining the effect of BRCA expression on the cellular response to several different classes of cytotoxic chemotherapeutic agents and radiation, using three experimental strategies for the comparison of BRCA-expressing and BRCA-nonexpressing cells: 1) conditional BRCA expression in BRCA-deficient human tumor cell lines; 2) direct comparison of BRCA-deficient and BRCA-wild-type tumor cell lines, and; 3) antisense-mediated BRCA depletion in BRCA-wild-type tumor cell lines. Data from these studies may lead to the development of more effective therapeutic strategies for genetically-defined subsets of ovarian cancer patients.