Title:	Multiple marker identification of rare tumor cells in blood and ascites of patients with metastatic diseases.
Authors:	Qiang Zhao1, Wei Zeng1, Donghai Chen1, Stanley Zucker1, Stefan Madajewicz1, Hossein Zarrabi1, Daniel Baram1, Paul Richman1, Michael Pearl3, John Chen4, Michael Frohman5, Marc G. Golightly6, Martin Karpeh7, Huan Dong1,2, Kwan-nan Yeh2, Yunyun Yeh2, & Wen-Tien Chen1,2 (1) Department of Medicine, (3) Department of Obstetrics, Gynecology and Reproductive Medicine; (4) Department of Preventive Medicine; (5) Department of Pharmacology; (6) Department of Pathology; (7) Department of Surgeon, State University of New York, Stony Brook NY 11794; (2) Vitatex Inc., 25 Health Sciences Drive, Stony Brook, NY 11790.
Presented At:	International Conference on "Tumor Progression & Therapeutic Resistance", at the Hilton City Avenue in Philadelphia, Pennsylvania, USA.
Date Presented:	November 8th & 9th, 2004
Abstract
Tumor associated markers, including MMP7, mucin 1, GA733-1, lipocalin 2 and cytokeratin 18, have been used successfully in characterizing primary and metastatic solid tumors. However, identification of the tumor cells emigrating in ascites and blood remains technically challenging because the emigrating tumor cells are few in number relative to the enormous numbers of normal cells, and because gene expression profiles of these rare cells is currently unknown. In order to identify rare tumor cells isolated from ascites and blood of patients with metastatic disease, we used a cell adhesion matrix (CAM) assay for cell enrichment and analyzed mRNA and protein expression of multiple epithelial/tumor associated cell lineage markers associated with primary tumors using real-time RT-PCR, immunocytochemistry and flow cytometry. Except for GA733-1, mRNA expression levels of MMP7, mucin 1, lipocalin 2 and cytokeratin 18 in tumor cells decreased in the following orders: primary tumors > ascites > blood. Furthermore, individual epithelial/tumor associated cell antigens (including pan-cytokeratins, EMA, muc 1, ESA, and BerEP4) were detectable in most tumor cells in primary sites, over 80% in ascites, and less than 40% in blood as compared to the number of tumor cells identified by combined antibodies against the five antigens. These results suggest that circulating tumor cells could be more accurately identified by combined multiple markers associated with primary tumors.