Establishing Claudin-2 as a Biomarker For Surgical Identification of Colorectal Cancer

Cancers originating in the peritoneal cavity are especially challenging to treat for a multitude of reasons, including diagnosis at a late stage of disease, relatively few intraoperative methods to assess the extent of disease, and lack of methods to detect tumor margins in real time for patients undergoing curative surgery. Patients with colorectal cancer, a leading cause of cancer-related death, would significantly benefit from knowing better the extent of disease to optimize treatment strategy and to maximize tumor removal during cytoreductive surgery. Recently, the development of fluorescence image-guided surgical systems and optical probes to better identify malignancies has enabled the possibility to intraoperatively guide tumor removal and assess margin status. There are now targeted optical probes for fluorescence-guided surgery. However, these are not designed for CRC. Accordingly, we propose to develop a near infrared fluorophore (NIRF) antibody conjugate that is specific for CRC. Claudin-2 (Cldn2), a tight junction transmembrane protein, has emerged as a critical regulator of epithelial barrier function and cellular permeability, and critically has significantly upregulated expression in CRC compared to low expression in surrounding tissue. Dr. Singh (MPI) has generated advanced models of CRC growth and progression using colonoscopy guided injection of the tumor cells into the colonic mucosa as well as novel murine models of CRC progression with genetic manipulation of colonic Cldn2 expression. On the other hand, Dr. Mohs (MPI), along with Dr. Singh and collaborators, have extensive experience at developing near infrared fluorescent (NIRF) imaging agents with controlled optical, targeting, and biodistribution properties for image-guided surgery. Most recently, we have focused on developing immunotargeted probes for a wide range of tumors, including GI malignancies. Overall, we reported strong, specific contrast in these studies. Key advantages of this approach for FGS are the availability of antibodies towards tumor-specific antigens and straight-forward NIRF conjugation procedures. Therefore, the goal of this proposal is to design NIRF imaging agents that can target specifically Cldn2 and that can demonstrate the feasibility of NIRF-antiCldn2 antibodies for contrast-enhanced colon cancer imaging using select in vitro and in vivo models. This goal will be accomplished by the following Specific Aims: (1) To synthesize and characterize NIRF anti-Cldn2 conjugates and establish specificity in tumor spheroid models and (2) To evaluate NIRF-antiCldn2 surgical imaging agents using in vivo CRC tumor models. Completion of this research project will identify a NIRF- antiCldn2 conjugate that specifically targets Cldn2 with in vivo evidence that these conjugates can target tumor xenografts in vivo, included an orthotopic model of CRC. These are essential data that are required for further preclinical development under larger funding mechanisms. Project Number: 1R21CA313619-01 | Fiscal Year: 2026 | NIH Institute/Center: National Cancer Institute (NCI) | Principal Investigator: Aaron Mohs (+1 co-PI) | Institution: UNIVERSITY OF NEBRASKA MEDICAL CENTER, OMAHA, NE | Award Amount: $409,120 | Activity Code: R21 | Study Section: Imaging Probes and Contrast Agents Study Section[IPCA] View on NIH RePORTER: https://reporter.nih.gov/project-details/11363536