MOUSE MODELS OF OVARIAN CANCER

我们提出了产生可遗传的卵巢癌小鼠模型的策略。 这些模型将有助于理解疾病的病因，并提供更现实的系统来评估诊断，预防和治疗方法。 建立转基因卵巢癌模型是一个特别合理的目标，考虑到这种疾病是美国妇女实体瘤死亡的第四大原因，目前存在三种更常见的致死性实体瘤的转基因模型。当人们考虑卵巢癌与乳腺癌相比的死亡风险时，进一步强调了对这种模型的需要。 在美国，卵巢癌的发病率约为每100，000名妇女中3.3人。 这每年产生大约20，000个新病例，但它们导致非常高的死亡频率，即每年近15，000名美国妇女死于这种疾病。 相比之下，乳腺癌的发病率约为每年180，000例，每年约有46，000人死亡。 因此，乳腺癌的发病率是卵巢癌的9倍，但死亡人数是卵巢癌的3倍。 在本申请中，我们证明了存在足够的资源来开始开发可遗传的卵巢癌模型，并描述了获得创建第二代模型所需的资源和信息的方法。 为了实现这些目标，我们提出了以下具体目标：具体目标1：识别过表达、异常表达或失活可能导致卵巢癌风险增加的基因：有足够的信息可以开始生产具有几个显性作用基因/致癌基因的转基因动物。 更大的问题在于选择调节作用基因，即那些功能丧失导致卵巢肿瘤发生的基因。 本目标的重点是鉴定用于转基因动物操作的此类基因。 具体目标2：创造基因工程小鼠，增加患卵巢癌的风险。我们已经确定了逆转录病毒样元件在大鼠基因组中，这是专门表达在大鼠卵巢。 我们已经克隆了负责卵巢特异性表达的部分，并证明它驱动报告基因表达。 该启动子将作为我们开发卵巢癌小鼠模型的初步努力的支柱。 在这个目标中，我们建议使用这个启动子创建组成型表达正常和突变基因的卵巢癌的重要性的转基因小鼠。 在隐性基因的情况下，即肿瘤/生长抑制基因，我们有能力产生生殖系“敲除”，但更感兴趣的是使用该启动子驱动卵巢特异性胞内抗体产生的可能性，作为以卵巢特异性方式功能性“敲除”肿瘤/生长抑制基因的手段。 特异性目的3：鉴定在MOSE细胞中特异性表达的启动子。 该启动子目前可在多种卵巢细胞类型包括表面上皮中发挥作用。 因此，当基因在该启动子的控制下被操纵时产生的卵巢肿瘤可能来自多种细胞类型。 尽管卵泡膜和颗粒细胞肿瘤在女性中不像表面上皮来源的肿瘤那样常见，但这种肿瘤模型将引起一定的兴趣。 在这里，我们建议确定一个小鼠卵巢表面上皮细胞特异性启动子。 具体目标4：增加癌症发生率和特异性，减少潜伏期。 在这里，我们将根据需要检查各种遗传和生理策略，以增加小鼠卵巢癌的发生频率，特异性和降低潜伏期。

We propose strategies to produce inheritable mouse models of ovarian cancer. Such models will aid in understanding the disease's etiology and provide more realistic systems in which to evaluate diagnostic, prevention, and treatment methods. Creation of transgenic ovarian cancer models is a particularly rational goal considering this disease is the fourth leading cause of deaths from solid tumors in American women and transgenic models of the three more commonly lethal solid tumors currently exist. The need for such models is further underscored when one considers the risk of death from ovarian cancer compared to for example breast cancer. The incidence of ovarian cancer is approximately 3.3 per 100,000 women in the United Sates. This yields approximately 20,000 new cases annually but they result in a remarkably high frequency of death, i.e. nearly 15,000 American women die from the disease each year. In contrast, breast cancer has a frequency of approximately 180,000 cases per year and accounts for approximately 46,000 annual deaths. Thus, breast cancer has a frequency 9 times as high as ovarian cancer but results in 3-times as many deaths. In this application, we demonstrate that sufficient resources exist to begin to develop inheritable models of ovarian cancer and describe approaches to obtain the resources and information needed to create second generation models. To accomplish these goals, we propose the following Specific Aims: SPECIFIC AIM number 1: Identify the genes which when overexpressed, expressed in aberrant form, or inactivated will likely lead to an increased risk of ovarian cancer: Sufficient information is available to start producing transgenic animals with several dominantly acting genes/oncogenes. A much larger problem exists with regard to selection of recessively acting genes, i.e. those genes whose lost function contributes to ovarian oncogenesis. Identification of such genes for manipulation in transgenic animals is the focus of this Aim. SPECIFIC AIM number 2: Creation of genetically engineered mice at increased risk of developing ovarian cancer. We have identified a retrovirus-like element in the rat genome which is specifically expressed in rat ovaries. We have cloned the portion of it responsible for ovarian specific expression and demonstrated that it drives reporter gene expression. This promoter will serve as the backbone of our initial efforts to develop mouse models of ovarian cancer. In this Aim, we propose to use this promoter to create transgenic mice constitutively expressing normal and mutated genes of importance in ovarian cancer. In the case of recessive genes, i.e. tumor/growth suppresser genes, we have the capability to produce germline "knockouts", but of greater interest is the possibility of using this promoter to drive ovarian specific intrabody production as a means to functionally "knockout" tumor/growth suppresser genes in an ovarian specific manner. SPECIFIC AIM number 3: Identify a promoter that is specifically expressed in MOSE cells. The promoter currently available functions in multiple ovarian cell types including the surface epithelium. Therefore, the ovarian tumors produced when genes are manipulated under control of this promoter may derive from multiple cell types. Such tumor models will be of certain interest although theca and granulosa cell tumors are not as common in women as those derived from the surface epithelium. Here, we propose to identify a mouse ovarian surface epithelial cell specific promoter. SPECIFIC AIM number 4: Increase carcinoma frequency and specificity and decrease latency. Here, we will examine various genetic and physiological strategies as needed to increase frequency, specificity, and decrease latency of ovarian cancer in mice.