Establishment of an exosome based liquid biomarker panel for disease activity and early detection of recurrence in Head and Neck Squamous Cell Carcinoma

• Applicant: Professorin Dr. Marie-Nicole Theodoraki
• Subject Area: Otolaryngology, Phoniatrics and Audiology
• Term: since 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 408387821

Head and Neck Squamous Cell Carcinomas (HNSCC) are characterized by profound immune suppression which is greatly mediated by exosomes. Exosomes are the smallest extracellular vesicles released by all cells and mediate intercellular communication. HNSCC are avid exosome producers (tumor-derived exosomes = TEX). TEX carry immunosuppressive molecules as PD-L1, tumor antigens or enzymes for production of immunosuppressive adenosine. Our previous studies revealed that exosomes alter immune cell functions and promote tumorigenesis. Further, we showed that TEX molecular cargo recapitulates the characteristic of the parent tumor cells and represents the immunosuppressive status of the tumor microenvironment, while at the same time it differs significantly from the cargo of healthy donor (HD)-exosomes. Overall, we identified various promising exosomal molecules that correlate with clinical parameters thus emphasizing their potential as liquid biomarkers for disease stage, tumor activity and progression. Exosomal information can further detect early recurrece before clinical evidence was visible. From our previous studies, the most promising exosomal biomarkers for HNSCC are:- Total exosome protein- TEX/non-TEX ratio- PD-L1, OX40-L, OX-40, CTLA-4 and CD16 exosome surface levels- Selected miRNAs and mRNAs- Adenosine production and cytotoxic T cell inhibition by exosomesOur project aims to combine these single targets to a standardized, sensitive and specific exosome-based liquid biomarker panel for easy and atraumatic determination of cancer onset and early detection of recurrence in HNSCC. For this purpose, blood from a big cohort of n = 100 newly diagnosed, treatment-naïve HNSCC patients and n = 100 age- and sex-matched HD will be collected. After informed consent, blood draw from HNSCC patients will take place prospectively at disease onset and every three months of follow up until an endpoint of two years. Plasma-derived exosomes will then be analyzed in a single-blinded setup regarding the following aims and methods:- Monitoring of disease onset and follow up: Measurement of exosomal protein, on-bead flow cytometry, RT-PCR- Monitoring of immune suppression status: In vitro co-incubation assays of T cells with exosomes followed by mass spectrometry (adenosine production) and flow cytometry (T cell activity)- Construction of an algorithm to create the most powerful combination of the above-mentioned liquid biomarkers with the fewest necessary single biomarker targetsWe aim to develop an exosome-based biomarker panel on RNA, protein and functional level with the highest sensitivity and specificity for the long-term use in clinical diagnostics of HNSCC but also in the follow up period for early identification of recurrence.

• DFG Programme: Research Grants
• International Connection: USA
• Cooperation Partners: Professor Dr. Edwin Jackson; Professorin Theresa L. Whiteside, Ph.D.