Abstract 1658: Anti-CEACAM binding protein for fluorescence visualization of primary colon cancer in patient-derived orthotopic xenograph mouse models

Background The Helicobacter outer protein (HopQ) is a novel surface-located Helicobacter pylori adhesion protein that binds to various human carcinoembryonic antigen-related cell adhesion molecules (CEACAM1, 3, 5, 6). Our aim was to validate fluorescence targeting of colorectal tumors in patient derived orthotopic xenograft models with fluorescently labeled HopQ. Materials/Methods CEACAM binding protein HopQ was conjugated to near-infrared dye IR800CW (LI-COR). Western blotting was performed with various colon cancer cell lysates to determine CEACAM expression. Nude mice (n=4) received orthotopic implantation of patient-derived primary colon tumors and patient-derived colon cancer metastases. Mice were administered either 25 ug or 50 ug of HopQ-IR800CW via tail vein injection and imaged 48 hours later. Intravital images were analyzed using the Image Studio Software Small Animal Imaging Analysis to determine tumor-to-background ratio (TBR). Results Western blotting demonstrated varied expression of CEACAM binding in all 15 patient derived colon cancer lysates. Dose response intravital imaging demonstrated TBR of 1.41 when administered 25 ug of HopQ-IR800CW and TBR 3.78 when administered 50 ug of HopQ-IR800CW. Conclusion CEACAM binding protein HopQ shows promising use for fluorescence imaging of patient derived orthotopic colon cancer. HopQ may be useful for tumor detection for pre-surgical diagnosis and fluorescence-guided surgery. Citation Format: Hannah M. Hollandsworth, Siamak Amirfakhri, Filemoni Filemoni, Verena Schmitt, Gunther Wennemuth, Alexej Schmidt, Robert M. Hoffman, Bernhard B. Singer, Michael Bouvet. Anti-CEACAM binding protein for fluorescence visualization of primary colon cancer in patient-derived orthotopic xenograph mouse models [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1658.