Site-specifically labeled CA19.9-targeted immunoconjugates for the PET, NIRF, and multimodal PET/NIRF imaging of pancreatic cancer Academic Article uri icon

Overview

MeSH Major

  • CA-19-9 Antigen
  • Immunoconjugates
  • Multimodal Imaging
  • Pancreatic Neoplasms
  • Positron-Emission Tomography
  • Spectroscopy, Near-Infrared

abstract

  • Molecular imaging agents for preoperative positron emission tomography (PET) and near-infrared fluorescent (NIRF)-guided delineation of surgical margins could greatly enhance the diagnosis, staging, and resection of pancreatic cancer. PET and NIRF optical imaging offer complementary clinical applications, enabling the noninvasive whole-body imaging to localize disease and identification of tumor margins during surgery, respectively. We report the development of PET, NIRF, and dual-modal (PET/NIRF) imaging agents, using 5B1, a fully human monoclonal antibody that targets CA19.9, a well-established pancreatic cancer biomarker. Desferrioxamine (DFO) and/or a NIRF dye (FL) were conjugated to the heavy-chain glycans of 5B1, using a robust and reproducible site-specific (ss) labeling methodology to generate three constructs ((ss)DFO-5B1, (ss)FL-5B1, and (ss)dual-5B1) in which the immunoreactivity was not affected by the conjugation of either label. Each construct was evaluated in a s.c. xenograft model, using CA19.9-positive (BxPC3) and -negative (MIAPaCa-2) human pancreatic cancer cell lines. Each construct showed exceptional uptake and contrast in antigen-positive tumors with negligible nonspecific uptake in antigen-negative tumors. Additionally, the dual-modal construct was evaluated in an orthotopic murine pancreatic cancer model, using the human pancreatic cancer cell line, Suit-2. The (ss)dual-5B1 demonstrated a remarkable capacity to delineate metastases and to map the sentinel lymph nodes via tandem PET-computed tomography (PET/CT) and NIRF imaging. Fluorescence microscopy, histopathology, and autoradiography were performed on representative sections of excised tumors to visualize the distribution of the constructs within the tumors. These imaging tools have tremendous potential for further preclinical research and for clinical translation.

publication date

  • December 29, 2015

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC4702985

Digital Object Identifier (DOI)

  • 10.1073/pnas.1506542112

PubMed ID

  • 26668398

Additional Document Info

start page

  • 15850

end page

  • 5

volume

  • 112

number

  • 52