Abstract 5530: Rejuvenation of dissociated cryopreserved human ovarian papillary serous tumor cells in an in vivo model.
Authors: Paik Daniel Y. , Janzen Deanna , Memarzadeh Sanaz 
Published: August 2014

Banked tumor tissues are a vital source of research material; however, current preservation techniques rely on flash-freezing. While this storage technique maintains the integrity of the nucleic acids and stable proteins, it does not allow for the recovery of live cells from the banked specimen. Serous carcinomas are the most common and deadliest form of gynecologic cancers. These tumors are heterogeneous with a wide array of genetic alterations. Our lab has developed a method which allows banking of live cells derived from primary ovarian serous papillary carcinoma specimens. Here we show that viable cell populations of interest can be isolated from banked cryopreserved tumor samples and grown in vivo as a potential source for analysis of individual tumors. Primary serous tumor samples were subjected to mechanical disruption and enzymatic digestion to produce dissociated cell suspensions. Samples were cryopreserved using controlled temperature reduction and stored in liquid nitrogen vapor. Viability of banked human tumor specimens was evaluated as the ability to establish a xenograft that histologically resembled the primary tumor. Serous tumor epithelia were isolated by flow cytometry using a cell surface marker, epithelial cell adhesion molecule (EpCAM), from this banked cryopreserved cellular population. Xenografts were generated by subcutaneous injection into NOD-scid IL2Rgammanull mice. Growth was monitored by palpation and regenerated tumors were analyzed for histology and marker expression profile. Nine serous tumor samples were banked using this method. To prove the viability of this cryopreservation process, 3 dissociated tumor cell preparations were thawed and injected into NOD-scid mice. Within 6 months, all 3 samples grew as xenografts that closely resembled the primary serous tumor. We then tested if viable cellular fractions of interest could be isolated from these banked serous tumors cells using fluorescent activated cell sorting. A subpopulation of tumors cells expressing EpCAM was collected from the cryopreserved tumor cell population and injected to establish xenografts. In this in vivo assay, xenografts grew as epithelial tumors in 7 of 9 cases. Our findings demonstrate that cryopreservation of dissociated primary tumor cells is a viable option for the generation of live cell tumor banks for papillary serous carcinoma. The advantages of a live cell tumor bank are numerous: 1) characterization of subpopulations of tumor cells in each patient's tumor sample at the RNA, DNA, and protein levels and 2) defining heterogeneity of a serous tumor with a special focus on identifying cancer initiating populations in each patient. We foresee that characterization of each patient's tumor sample using this live tissue bank may help individualize therapeutic strategies in patients with serous cancers.

Citation Format: Daniel Y. Paik, Deanna Janzen, Sanaz Memarzadeh. Rejuvenation of dissociated cryopreserved human ovarian papillary serous tumor cells in an in vivo model. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5530. doi:10.1158/1538-7445.AM2013-5530