The use of a novel MUC1 antibody to identify cancer stem cells and circulating MUC1 in mice and patients with pancreatic cancer

Background and Objectives MUC1 is over‐expressed and aberrantly glycosylated in >60% of human pancreatic cancer (PC). Development of novel approaches for detection and/or targeting of MUC1 are critically needed and should be able to detect MUC1 on PC cells (including cancer stem cells) and in serum. Methods The sensitivity and specificity of the anti‐MUC1 antibody, TAB 004, was determined. CSCs were assessed for MUC1 expression using TAB 004‐FITC on in vitro PC cell lines, and on lineage− cells from in vivo tumors and human samples. Serum was assessed for shed MUC1 via the TAB 004 EIA. Results In vitro and in vivo, TAB 004 detected MUC1 on >95% of CSCs. Approximately, 80% of CSCs in patients displayed MUC1 expression as detected by TAB 004. Shed MUC1 was detected serum in mice with HPAF‐II (MUC1high) but not BxPC3 tumors (MUC1low). The TAB 004 EIA was able to accurately detect stage progression in PC patients. Conclusions The TAB 004 antibody may be explored as a therapeutic targeting agent for CSCs in PC. The TAB 004 EIA detected circulating MUC1 in a stage‐dependent manner in patients with PC and thus may be explored as a PC stage diagnostic biomarker. J. Surg. Oncol. 2013;107:713–722. © 2013 Wiley Periodicals, Inc.