Development and validation of preclinical mouse model for serous ovarian cancer

CAPR已经建立了一种深入研究的浆液性上皮性卵巢癌基因工程小鼠模型。loxP/Cre系统用于干扰Rb、p53和/或Brca 1/Brca 2通路，特异性地在卵巢上皮中。 目前，正在测试不同的诱导系统以确定浆液性卵巢癌模型的最佳设计，该模型适用于挖掘癌症类型中肿瘤发生的基础生物学以及随后的临床前药物评价：1）在6周龄时通过存活手术将Adeno-Cre感染到卵巢囊中。2)使用他莫昔芬诱导的MisIIR-CreER系统的遗传诱导。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囊中。我们的数据显示，使用腺病毒诱导的Brca 1、p53和Rb通路组分的组合缺失导致诱导后10个月的转移性卵巢癌伴腹水。目前正在分析基因突变及其组合对疾病发作和进展的影响。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。肿瘤样本将进行人类和小鼠癌症的跨物种组学分析，以确定可以为癌症治疗提供新的药物靶点的共同分子特征。在本项目的第二阶段，将比较所有三种肿瘤诱导方法在生产用于临床前疗效测定的大型队列中的适用性。作为先导实验，CAPR的研究和模型开发团队诱导了一个大型动物队列，该队列具有几种遗传事件（pRb失活、p53失活和体细胞诱导的诱变、BRCA 1/2失活）的组合。通过囊内施用腺病毒转导的Cre重组酶进行诱导。这个约800只动物的队列发展了不同阶段的卵巢恶性肿瘤，使CAPR科学家能够对所产生的肿瘤进行深入的病理组织学研究，并收集血液，腹水和癌性与良性组织样本进行分子分析和建立原代细胞培养。这些数据目前正在由CCR生物信息学核心或与Kohn博士和Annunziata的临床小组合作，通过现代生物信息学/系统生物学方法进行分析。一个比较评估正在进行中，以及与类似的数据集获得的马克辛普森的实验室在收集人类SEOC临床样本。 作为这些努力的一个关键科学成果，与货车戴克博士以前在北卡罗来纳州大学的实验室合作，在《癌症研究》上发表了一篇论文，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。为了在临床前工作流程中应用该模型，CAPR正处于与一家潜在的大型制药合作伙伴谈判的后期阶段，该合作伙伴预计将在公司专有的选择性蛋白酶体抑制剂化合物的临床前评估项目中采用SEC模型。

CAPR has established and characterized in-depth 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/Brca2 pathways specifically in the ovarian epithelium. 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.Our 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. These data are currently being analyzed by modern bioinformatics/systems biology approaches by the CCR Bioinformatics Core or in collaboration with Drs. Kohn's and Annunziata's clinical groups. A comparative evaluation is under way as well with the similar data sets obtained by Mark Simpson's lab in a collection of human SEOC clinical samples. As a key scientific output of these efforts, in collaboration with Dr. Van Dyke's previous lab at the University of North Carolina, a manuscript had been published in Cancer Research, describing this specific genetic approach to model the metastatic serous ovarian cancer and molecular observations related to SEOC tumor progression and histopathologic attributes. To apply the model in preclinical workflows, CAPR is in an advanced stage of negotiations with a prospective Big Pharma partner who anticipates to employ the SEC model in a preclinical evaluation project for Company's proprietary selective proteasome inhibitor compound.