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

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.

Comparison of PD-L1 expression in squamous cell cancer of unknown primary and oropharyngeal squamous cell carcinoma.

PURPOSE: The tumorigenesis of squamous cell cancer of unknown primary (SCCUP) in the head and neck area has not been decoded so far, while poor survival rates and limited therapeutic options pose a serious challenge. The aim of this project was to investigate immunological characteristics of SCCUPs and compare them to oropharyngeal squamous cell carcinoma (OPSCC). METHODS: PD-L1 expression (TC) was examined by immunohistochemistry in 50 lymph node metastases of SCCUP and 47 primaries of OPSCC. CD3 + and CD8 + lymphocytic infiltration was measured in 5 high power fields. Expression of p16 and HPV ISH were assessed. RESULTS: SCCUP demonstrated a significantly higher expression of PD-L1 than OPSCC. In p16-negative SCCUPs PD-L1 proved to be an independent prognostic factor to prioritize high-risk patients. CONCLUSIONS: Immunologic differences between SCCUP and OPSCC were detected. A higher PD-L1 expression in SCCUP could potentially facilitate further evaluation of checkpoint inhibitor therapy.

Comparative study of virus and lymphocyte distribution with clinical data suggests early high dose immunosuppression as potential key factor for the therapy of patients with BoDV-1 infection.

ABSTRACTBorna disease virus 1 (BoDV-1) was just recently shown to cause predominantly fatal encephalitis in humans. Despite its rarity, bornavirus encephalitis (BVE) can be considered a model disease for encephalitic infections caused by neurotropic viruses and understanding its pathomechanism is of utmost relevance. Aim of this study was to compare the extent and distribution pattern of cerebral inflammation with the clinical course of disease, and individual therapeutic procedures. For this, autoptic brain material from seven patients with fatal BVE was included in this study. Tissue was stained immunohistochemically for pan-lymphocytic marker CD45, the nucleoprotein of BoDV-1, as well as glial marker GFAP and microglial marker Iba1. Sections were digitalized and counted for CD45-positive and BoDV-1-positive cells. For GFAP and Iba1, a semiquantitative score was determined. Furthermore, detailed information about the individual clinical course and therapy were retrieved and summarized in a standardized way. Analysis of the distribution of lymphocytes shows interindividual patterns. In contrast, when looking at the BoDV-1-positive glial cells and neurons, a massive viral involvement in the brain stem was noticeable. Three of the seven patients received early high-dose steroids, which led to a significantly lower lymphocytic infiltration of the central nervous tissue and a longer survival compared to the patients who were treated with steroids later in the course of disease. This study highlights the potential importance of early high-dose immunosuppressive therapy in BVE. Our findings hint at a promising treatment option which should be corroborated in future observational or prospective therapy studies.ABBREVIATIONS: BoDV-1: Borna disease virus 1; BVE: bornavirus encephalitis; Cb: cerebellum; CNS: central nervous system; FL: frontal lobe; GFAP: glial fibrillary acid protein; Hc: hippocampus; Iba1: ionized calcium-binding adapter molecule 1; Iba1act: general activation of microglial cells; Iba1nod: formation of microglial nodules; IL: insula; Me: mesencephalon; Mo: medulla oblongata; OL: occipital lobe; pASS: per average of 10 screenshots; patearly: patients treated with early high dose steroid shot; patlate: patients treated with late or none high dose steroid shot; Po: pons; So: stria olfactoria; Str: striatum.

Head and neck cancer of unknown primary: unveiling primary tumor sites through machine learning on DNA methylation profiles.

BACKGROUND: The unknown tissue of origin in head and neck cancer of unknown primary (hnCUP) leads to invasive diagnostic procedures and unspecific and potentially inefficient treatment options for patients. The most common histologic subtype, squamous cell carcinoma, can stem from various tumor primary sites, including the oral cavity, oropharynx, larynx, head and neck skin, lungs, and esophagus. DNA methylation profiles are highly tissue-specific and have been successfully used to classify tissue origin. We therefore developed a support vector machine (SVM) classifier trained with publicly available DNA methylation profiles of commonly cervically metastasizing squamous cell carcinomas (n = 1103) in order to identify the primary tissue of origin of our own cohort of squamous cell hnCUP patient's samples (n = 28). Methylation analysis was performed with Infinium MethylationEPIC v1.0 BeadChip by Illumina. RESULTS: The SVM algorithm achieved the highest overall accuracy of tested classifiers, with 87%. Squamous cell hnCUP samples on DNA methylation level resembled squamous cell carcinomas commonly metastasizing into cervical lymph nodes. The most frequently predicted cancer localization was the oral cavity in 11 cases (39%), followed by the oropharynx and larynx (both 7, 25%), skin (2, 7%), and esophagus (1, 4%). These frequencies concord with the expected distribution of lymph node metastases in epidemiological studies. CONCLUSIONS: On DNA methylation level, hnCUP is comparable to primary tumor tissue cancer types that commonly metastasize to cervical lymph nodes. Our SVM-based classifier can accurately predict these cancers' tissues of origin and could significantly reduce the invasiveness of hnCUP diagnostics and enable a more precise therapy after clinical validation.

A distinct stimulatory cDC1 subpopulation amplifies CD8+ T cell responses in tumors for protective anti-cancer immunity.

Type 1 conventional dendritic cells (cDC1) can support T cell responses within tumors but whether this determines protective versus ineffective anti-cancer immunity is poorly understood. Here, we use imaging-based deep learning to identify intratumoral cDC1-CD8+ T cell clustering as a unique feature of protective anti-cancer immunity. These clusters form selectively in stromal tumor regions and constitute niches in which cDC1 activate TCF1+ stem-like CD8+ T cells. We identify a distinct population of immunostimulatory CCR7neg cDC1 that produce CXCL9 to promote cluster formation and cross-present tumor antigens within these niches, which is required for intratumoral CD8+ T cell differentiation and expansion and promotes cancer immune control. Similarly, in human cancers, CCR7neg cDC1 interact with CD8+ T cells in clusters and are associated with patient survival. Our findings reveal an intratumoral phase of the anti-cancer T cell response orchestrated by tumor-residing cDC1 that determines protective versus ineffective immunity and could be exploited for cancer therapy.

NOTCH1 Intracellular Domain and the Tumor Microenvironment as Prognostic Markers in HNSCC.

(1) Background: NOTCH1 is the second most common mutated gene in whole-exome sequencing of HNSCC. The aim of this project was to gain further insight into the relevance of NOTCH1 in HNSCC, potentially establishing NOTCH1 as a prognostic marker or therapeutic target; (2) Methods: NOTCH1 was silenced via RNA interference in six HNSCC cell lines and the impact was evaluated in migration and proliferation assays. Subsequently, the protein expression of NOTCH1 intracellular domain (NICD) and NOTCH1 mRNA expression were examined in 70 oropharyngeal squamous cell cancer tissue samples. Lastly, the NICD expression was compared with the local infiltration of lymphocytes, measured with the immunoscore; (3) Results: Knockdown of NOTCH1 decreased migration and proliferation. A high NICD expression was associated with lower OS. A high immunoscore resulted in significantly better OS. NICD expression was independent of the immunoscore and as a whole differentiated three distinct prognostic groups; (4) Conclusions: These data suggest that NOTCH1 is involved in migration and proliferation of HNSCC cell lines. In vivo, NICD expression was associated with overall survival and could, therefore, be used as a prognostic marker. NICD expression differs from NOTCH1 mRNA levels, potentially explaining the previously suggested bimodal role as an oncogene and tumor suppressor in HNSCC.

Comparing TIMP-1 and Hsp70 in Blood and Saliva as Potential Prognostic Markers in HNSCC.

(1) Background: Currently, there is no clinically used liquid biomarker in head and neck squamous cell carcinoma (HNSCC) patients. One reason could be the limited shedding of tumor material in early disease stages. Molecular diagnostics assessing both blood and especially saliva could potentially improve the accuracy of biomarkers. In this prospective study, two markers, tissue inhibitor of metalloprotease-1 (TIMP-1) and heat shock protein 70 (Hsp70), were analyzed in HNSCC patients. The purpose of the study was to evaluate differences between saliva and serum as sample material. Further, their prognostic and predictive value and usefulness for early detection was assessed. (2) Methods: A total of 73 HNSCC patients were prospectively monitored by collecting blood and saliva before, during, and after therapy, as well as in the follow-up period between 2018 and 2021. In total, 212 serum and 194 saliva samples were collected. A control group consisting of 40 subjects (15 patients with local infections in the head and neck area and 25 without infections) were examined as well. The collected samples were evaluated for the two proteins by using an enzyme-linked immunosorbent assay (ELISA). (3) RESULTS: The TIMP-1 concentration correlated significantly in blood and saliva, whereas the Hsp70 concentration did not. Saliva TIMP-1 was significantly higher in tumor patients compared to the control group (p = 0.013). High pretreatment TIMP-1 saliva levels were associated with significantly poorer disease-free survival (DFS) (p = 0.02). A high saliva TIMP-1/Hsp70 ratio was significantly associated with poorer DFS (HR: 1.4; 95% CI: 1.04-1.88; p = 0.026) and a high TIMP-1 serum concentration was significantly associated with poorer PFS (HR: 1.9; 95% CI: 1.2, 2.8; p = 0.003) and poorer overall survival (OS) (HR: 2.9; 95% CI: 1.4, 5.9; p = 0.003) in the Cox proportional hazards model. The saliva TIMP-1 to Hsp70 ratio was significantly higher at the time of recurrence (p = 0.015). Conclusion: TIMP-1 in serum is a promising prognostic marker for HNSCC. Saliva TIMP-1 and the saliva TIMP-1 to Hsp70 ratio provides additional information on the disease-free survival.