Near-Infrared In Vivo Imaging of Claudin-1 Expression by Orthotopically Implanted Patient-Derived Colonic Adenoma Organoids

TL;DR

Researchers used imaging to detect increased claudin-1 in colon cancer organoids implanted in mice, showing potential for early cancer detection.

Contribution

A novel in vivo imaging method using NIR fluorescence to detect claudin-1 in patient-derived organoids is introduced.

Findings

NIR fluorescence imaging showed higher target-to-background ratios in adenoma versus normal colonoids.

Optical sections confirmed claudin-1 overexpression in adenomatous epithelial cells.

Human-specific cytokeratin staining verified human tissue presence in mouse colons.

Abstract

Background: Claudin-1 becomes overexpressed during the transformation of normal colonic mucosa to colorectal cancer (CRC). Methods: Patient-derived organoids expressed clinically relevant target levels and genetic heterogeneity, and were established from human adenoma and normal colons. Colonoids were implanted orthotopically in the colon of immunocompromised mice. This pre-clinical model of CRC provides an intact microenvironment and representative vasculature. Colonoid growth was monitored using white light endoscopy. A peptide specific for claudin-1 was fluorescently labeled for intravenous administration. NIR fluorescence images were collected using endoscopy and endomicroscopy. Results: NIR fluorescence images collected using wide-field endoscopy showed a significantly greater target-to-background (T/B) ratio for adenoma versus normal (1.89 ± 0.35 and 1.26 ± 0.06) colonoids at 1 h post-injection. These results were confirmed by optical sections collected using endomicroscopy. Optical sections were collected in vivo with sub-cellular resolution in vertical and horizontal planes. Greater claudin-1 expression by individual epithelial cells in adenomatous versus normal crypts was visualized. A human-specific cytokeratin stain ex vivo verified the presence of human tissues implanted adjacent to normal mouse colonic mucosa. Conclusions: Increased claudin-1 expression was observed from adenoma versus normal colonoids in vivo using imaging with wide field endoscopy and endomicrosopy.

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