Abstract POSTER-TECH-1114: Single-cell molecular profiling of fluid biopsies of epithelial ovarian cancer
Authors: Velasco Carmen Ruiz , Stepansky Asya , Dago Angel , Carlson Anders , Kolatkar Anand , Kendall Jude , Hicks James , Kuhn Peter 
Published: August 2015

The immediate goal of this project is to identify rare circulating tumor cells (CTC) in the bloodstream of epithelial ovarian cancer (EOC) patients and to apply high content, single cell assays that will yield information on morphology, protein expression and genomic structure. The ultimate goal is to develop a minimally invasive “fluid biopsy” for ovarian patients that can provide detailed information on the patient’s response to therapy, early warnings of potential resistance or relapse, and genetic predictors for the most appropriate therapy.

The onset of pharmacogenomics has opened the door to a future of precision-guided therapies for cancer. Although as yet not implemented in all cancers, the idea of matching therapy to the molecular genetic characteristics of an individual cancer has been realized for specific classes of breast, lung and prostate cancers. For metastatic ovarian cancer patients the most efficient and convenient way to monitor the continuous state of the patient is through the presence of circulating epithelial cells (CTCs) that are shed from metastatic sites into the bloodstream. The difficulty, of course, is detecting and isolating these cells from the tens of millions of endothelial leukocytes (white blood cells) in a standard blood draw.

We have created the HD-CTC assay for visualizing these rare CTC from blood samples and measuring their morphology, protein expression and genomic structure. Briefly, after initial processing to remove red blood cells, the blood samples are deposited on glass slides, stained and examined with a high-speed optical scanner. Epithelial (cancer) cells are distinguished from white blood cells by the presence of a complex of cytokeratin molecules in the cell. Each epithelial cell is imaged and its position recorded along with morphometric data including overall cell and nuclear size and shape. The positional information is used to retrieve individual cells for DNA extraction and DNA sequencing. The DNA sequence is initially converted into a genomic profile of copy number variation (CNV) and can be further sequenced for single nucleotide mutations.

With support from the Rivkin Foundation we will obtain blood samples from up to 20 Stage 4 epithelial ovarian cancer patients at sequential times during their cycles of treatment and perform full HD-CTC assays including CTC enumeration, protein expression and genomic analysis of individual cells in order to determine the specific genetic alterations present in each cell and the degree of variation present within each case. Coupled with clinical information, including C125 levels and response to therapy, plus genetic information from bulk primary and metastatic tissue, we expect to establish the landscape of the circulating cell compartment in EOC and begin to understand the relationship of CTC to the metastatic behavior and patient prognosis.

Citation Format: Carmen Ruiz Velasco, Asya Stepansky, Angel Dago, Anders Carlson, Anand Kolatkar, Jude Kendall, James Hicks , Peter Kuhn. Single-cell molecular profiling of fluid biopsies of epithelial ovarian cancer [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-TECH-1114.