Improved ex vivo fluorescence imaging of human head and neck cancer using the peptide tracer TPP-IRDye800 targeting membrane-bound Hsp70 on tumor cells

• Published in: British journal of cancer 2024-12, Vol.131 (11), p.1814-1824
• Main Authors: Holzmann, Katharina L. K., Wolf, Johanna L., Stangl, Stefan, Lennartz, Philipp, Kasajima, Atsuko, Mogler, Carolin, Haller, Bernhard, Ebert, Eva-Vanessa, Jira, Daniel, Lauterbach, Maren L. A., von Meyer, Franziska, Stark, Leonhard, Mauch, Leonie, Schmidl, Benedikt, Wollenberg, Barbara, Multhoff, Gabriele, Wirth, Markus
• Format: Article
• Language: English
• Subjects: 692/308/575; 692/4028/546; Biomedical and Life Sciences; Biomedicine; Cancer Research; Cell Line, Tumor; Cetuximab; Drug Resistance; Epidemiology; Female; Flow cytometry; Fluorescence microscopy; Fluorescent Dyes; Gene expression; Head & neck cancer; Head and Neck Neoplasms - diagnostic imaging; Head and Neck Neoplasms - metabolism; Head and Neck Neoplasms - pathology; HSP70 Heat-Shock Proteins - metabolism; Hsp70 protein; Humans; Indoles; Male; Medical imaging; Metastases; Metastasis; Microscopy, Fluorescence - methods; Middle Aged; Molecular Medicine; Monoclonal antibodies; Oncology; Optical Imaging - methods; Peptides; Peptides - metabolism; Squamous Cell Carcinoma of Head and Neck - diagnostic imaging; Squamous Cell Carcinoma of Head and Neck - metabolism; Squamous Cell Carcinoma of Head and Neck - pathology; Tumor cells; Tumors
• ISSN: 0007-0920; 1532-1827; 1532-1827
• DOI: 10.1038/s41416-024-02872-8

Background The primary goal of surgery in HNSCC is the complete resection of tumor cells with maximum preservation of normal tissue. The membrane Hsp70-targeting fluorescence labelled peptide TPP-IRDye800 represents a promising tool for real-time intraoperative tumor visualization, enabling the detection of true tumor margins, critical isles of high-grade dysplasia and LN metastases. Methods Membrane Hsp70 (mHsp70) expression on HNSCC cell lines and primary HNSCC was determined by flow cytometry and fluorescence microscopy using FITC-conjugated mAb cmHsp70.1 and TPP. TPP-IRDye800 was sprayed on freshly resected tumor material of immunohistochemically confirmed HNSCC and LN metastases for tumor imaging. TBRs were compared using TPP-IRDye800 and Cetuximab-IRDye680, recognizing EGFR. Results mHsp70 expressing HNSCC cells specifically bind and internalize TPP in vitro. The TBR (2.56 ± 0.39) and AUC [0.98 CI, 0.95–1.00 vs. 0.91 CI, 0.85–0.97] of TPP-IRDye800 on primary HNSCC was significantly higher than Cetuximab-IRDye680 (1.61 ± 0.39) ( p  = 0.0068) and TPP-IRDye800 provided a superior tumor delineation. Fluorescence imaging showed higher AUC values than a visual inspection by surgeons [0.97 CI, 0.94–1.00 vs. 0.92 CI, 0.88–0.97] ( p  = 0.048). LN metastases could be visualized using TPP-IRDye800. Real-time tissue delineation was confirmed using the clinically applied KARL-STORZ imaging system. Conclusion TPP-IRDye800 is a promising fluorescence imaging probe for HNSCC.