Development and validation of preclinical mouse model for serous ovarian cancer

CAPR正在建立浆液性卵巢上皮癌的基因工程小鼠模型。LoxP/Cre系统被用来干扰Rb、P53和/或BRCA1和BRCA2通路，特别是在卵巢(图1)。目前，人们正在测试不同的诱导系统，以确定最优的浆液性卵巢癌模型设计，该模型既适用于挖掘肿瘤类型的肿瘤发生的基本生物学，也适用于随后的临床前药物评估：1)6周龄时存活手术将腺Cre感染到卵巢的法氏囊。2)使用三苯氧胺可诱导的MisIIR-Creer系统进行遗传诱导。3)将原代卵巢上皮细胞或卵巢肿瘤细胞原位移植到同基因小鼠的法氏囊内。初步数据显示，在腺病毒诱导下，BRCA1、P53和Rb通路成分的联合缺失会在诱导后10个月内导致转移性卵巢癌并腹水。目前正在分析基因突变及其组合对疾病发生和发展的影响。前瞻性研究旨在跟踪生物标志物并改进成像策略，这些策略可以在临床上转化并应用于早期疾病检测。肿瘤样本将接受人类和小鼠癌症的跨物种基因组分析，以确定可能为癌症治疗提供新的可药物靶点的共同分子特征。在该项目的第二阶段，将比较所有三种肿瘤诱导方法在生产用于临床前疗效确定的大队列中的适用性。作为一项先导实验，CAPR的研究和模型开发团队诱导了一大批具有几种遗传事件组合(PRB失活、P53失活和体细胞诱导突变、BRCA1/2失活)的动物。诱导是通过法氏囊内腺病毒转导的Cre重组酶进行的。这个由大约800只动物组成的队列发生了卵巢恶性肿瘤的不同阶段，使CAPR的科学家能够对由此产生的肿瘤进行深入的病理组织学研究，并收集血液、腹水和癌与良性组织样本用于分子分析和建立原代细胞培养。收集的数据目前由CCR生物信息学核心或与Kohn博士和Annunziata临床小组合作的现代生物信息学方法进行分析。与此同时，与Van Dyke博士之前在北卡罗来纳大学的实验室合作，一份手稿正在准备中，描述了这种特定的遗传方法来模拟转移性浆液性卵巢癌，以及与SEOC肿瘤进展和组织病理学属性相关的分子观察。

CAPR is establishing a genetically engineered mouse model of serous epithelial ovarian carcinoma. The loxP/Cre system is used to perturb the Rb, p53 and/or the Brca1 and Brca2 pathways specifically in the ovaries (Fig. 1). Currently, different induction systems are being tested to determine the most optimal design of serous ovarian cancer model applicable both for mining the basic biology of tumorigenesis in cancer type and subsequently for preclinical drug evaluation: 1) Adeno-Cre infection into the bursa of the ovary by survival surgery at 6 weeks of age. 2) Genetic induction using a tamoxifen-inducible MisIIR-CreER system. 3) Orthotopic transplantation of primary ovarian epithelial cells or ovarian tumor cells into the bursa of syngeneic mice. Preliminary data showed that the combined deletion of Brca1, p53 and the Rb pathway components using adenoviral induction leads to metastatic ovarian cancer with ascites by 10 months post-induction. The impact of genetic mutations and combinations thereof on the onset and progression of the disease is currently being analyzed. Prospective studies are designed to track biomarkers and improve imaging strategies that could be clinically translated and applied for early disease detection. Tumor samples will be subject to cross species omic analyses of human and mouse cancers to identify common molecular signatures that could provide new druggable targets for cancer therapeutics. In the second phase of this project, all three tumor induction approaches will be compared for their applicability for the production of large cohorts for preclinical efficacy determination. As a pilot experiment, the Research and Model Development team of CAPR induced a large cohort of animals featuring several combination of genetic events (pRb inactivation, p53 inactivation and somatically induced mutagenesis, BRCA1/2 inactivation). The induction had been performed via intra-bursa administration of adenovirally transduced Cre recombinase. This cohort of approximately 800 animals developed various stages of ovarian malignancy allowing CAPR scientists to undergo in-depth patho-histologic investigation of resulting tumors, as well as to collect blood, ascites and cancerous vs. benign tissue samples for molecular analyses and establishing primary cell cultures. Collected data are currently analysed by modern bioinformatics approaches by the CCR Bioinformatics Core or in collaboration with Drs. Kohn's and Annunziata's clinical groups. In parallel, in collaboration with Dr. Van Dyke's previous lab at the University of North Carolina, a manuscript is in preparation, describing this specific genetic approach to model the metastatic serous ovarian cancer and molecular observations related to SEOC tumor progression and histopathologic attributes.