TY - JOUR A1 - Stefanakis, Mona A1 - Bassler, Miriam C. A1 - Walczuch, Tobias R. A1 - Gerhard-Hartmann, Elena A1 - Youssef, Almoatazbellah A1 - Scherzad, Agmal A1 - Stöth, Manuel Bernd A1 - Ostertag, Edwin A1 - Hagen, Rudolf A1 - Steinke, Maria R. A1 - Hackenberg, Stephan A1 - Brecht, Marc A1 - Meyer, Till Jasper T1 - The impact of tissue preparation on salivary gland tumors investigated by Fourier-transform infrared microspectroscopy JF - Journal of Clinical Medicine N2 - Due to the wide variety of benign and malignant salivary gland tumors, classification and malignant behavior determination based on histomorphological criteria can be difficult and sometimes impossible. Spectroscopical procedures can acquire molecular biological information without destroying the tissue within the measurement processes. Since several tissue preparation procedures exist, our study investigated the impact of these preparations on the chemical composition of healthy and tumorous salivary gland tissue by Fourier-transform infrared (FTIR) microspectroscopy. Sequential tissue cross-sections were prepared from native, formalin-fixed and formalin-fixed paraffin-embedded (FFPE) tissue and analyzed. The FFPE cross-sections were dewaxed and remeasured. By using principal component analysis (PCA) combined with a discriminant analysis (DA), robust models for the distinction of sample preparations were built individually for each parotid tissue type. As a result, the PCA-DA model evaluation showed a high similarity between native and formalin-fixed tissues based on their chemical composition. Thus, formalin-fixed tissues are highly representative of the native samples and facilitate a transfer from scientific laboratory analysis into the clinical routine due to their robust nature. Furthermore, the dewaxing of the cross-sections entails the loss of molecular information. Our study successfully demonstrated how FTIR microspectroscopy can be used as a powerful tool within existing clinical workflows. KW - formalin KW - fixation KW - tissue preparation KW - salivary gland neoplasia KW - FTIR spectroscopy KW - principal component analysis KW - discriminant analysis Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304887 SN - 2077-0383 VL - 12 IS - 2 ER - TY - JOUR A1 - Moratin, Helena A1 - Ickrath, Pascal A1 - Scherzad, Agmal A1 - Meyer, Till Jasper A1 - Naczenski, Sebastian A1 - Hagen, Rudolf A1 - Hackenberg, Stephan T1 - Investigation of the immune modulatory potential of zinc oxide nanoparticles in human lymphocytes JF - Nanomaterials N2 - Zinc oxide nanoparticles (ZnO-NP) are commonly used for a variety of applications in everyday life. In addition, due to its versatility, nanotechnology supports promising approaches in the medical sector. NP can act as drug-carriers in the context of targeted chemo- or immunotherapy, and might also exhibit autonomous immune-modulatory characteristics. Knowledge of potential immunosuppressive or stimulating effects of NP is indispensable for the safety of consumers as well as patients. In this study, primary human peripheral blood lymphocytes of 9 donors were treated with different sub-cytotoxic concentrations of ZnO-NP for the duration of 1, 2, or 3 days. Flow cytometry was performed to investigate changes in the activation profile and the proportion of T cell subpopulations. ZnO-NP applied in this study did not induce any significant alterations in the examined markers, indicating their lack of impairment in terms of immune modulation. However, physicochemical characteristics exert a major influence on NP-associated bioactivity. To allow a precise simulation of the complex molecular processes of immune modulation, a physiological model including the different components of an immune response is needed. KW - zinc oxide nanoparticles KW - immunomodulation KW - T cell subpopulations Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234016 SN - 2079-4991 VL - 11 IS - 3 ER - TY - JOUR A1 - Meyer, Till Jasper A1 - Stöth, Manuel A1 - Moratin, Helena A1 - Ickrath, Pascal A1 - Herrmann, Marietta A1 - Kleinsasser, Norbert A1 - Hagen, Rudolf A1 - Hackenberg, Stephan A1 - Scherzad, Agmal T1 - Cultivation of head and neck squamous cell carcinoma cells with wound fluid leads to cisplatin resistance via epithelial-mesenchymal transition induction JF - International Journal of Molecular Sciences N2 - Locoregional recurrence is a major reason for therapy failure after surgical resection of head and neck squamous cell carcinoma (HNSCC). The physiological process of postoperative wound healing could potentially support the proliferation of remaining tumor cells. The aim of this study was to evaluate the influence of wound fluid (WF) on the cell cycle distribution and a potential induction of epithelial-mesenchymal transition (EMT). To verify this hypothesis, we incubated FaDu and HLaC78 cells with postoperative WF from patients after neck dissection. Cell viability in dependence of WF concentration and cisplatin was measured by flow cytometry. Cell cycle analysis was performed by flow cytometry and EMT-marker expression by rtPCR. WF showed high concentrations of interleukin (IL)-6, IL-8, IL-10, CCL2, MCP-1, EGF, angiogenin, and leptin. The cultivation of tumor cells with WF resulted in a significant increase in cell proliferation without affecting the cell cycle. In addition, there was a significant enhancement of the mesenchymal markers Snail 2 and vimentin, while the expression of the epithelial marker E-cadherin was significantly decreased. After cisplatin treatment, tumor cells incubated with WF showed a significantly higher resistance compared with the control group. The effect of cisplatin-resistance was dependent on the WF concentration. In summary, proinflammatory cytokines are predominantly found in WF. Furthermore, the results suggest that EMT can be induced by WF, which could be a possible mechanism for cisplatin resistance. KW - cell proliferation KW - wound fluid KW - epithelial-mesenchymal transition KW - cisplatin resistance KW - Interleukin KW - head and neck squamous cell carcinoma Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258722 SN - 1422-0067 VL - 22 IS - 9 ER - TY - JOUR A1 - Meyer, Till Jasper A1 - Scherzad, Agmal A1 - Moratin, Helena A1 - Gehrke, Thomas Eckert A1 - Killisperger, Julian A1 - Hagen, Rudolf A1 - Wohlleben, Gisela A1 - Polat, Bülent A1 - Dembski, Sofia A1 - Kleinsasser, Norbert A1 - Hackenberg, Stephan T1 - The radiosensitizing effect of zinc oxide nanoparticles in sub-cytotoxic dosing is associated with oxidative stress in vitro JF - Materials N2 - Radioresistance is an important cause of head and neck cancer therapy failure. Zinc oxide nanoparticles (ZnO-NP) mediate tumor-selective toxic effects. The aim of this study was to evaluate the potential for radiosensitization of ZnO-NP. The dose-dependent cytotoxicity of ZnO-NP\(_{20 nm}\) and ZnO-NP\(_{100 nm}\) was investigated in FaDu and primary fibroblasts (FB) by an MTT assay. The clonogenic survival assay was used to evaluate the effects of ZnO-NP alone and in combination with irradiation on FB and FaDu. A formamidopyrimidine-DNA glycosylase (FPG)-modified single-cell microgel electrophoresis (comet) assay was applied to detect oxidative DNA damage in FB as a function of ZnO-NP and irradiation exposure. A significantly increased cytotoxicity after FaDu exposure to ZnO-NP\(_{20 nm}\) or ZnO-NP\(_{100 nm}\) was observed in a concentration of 10 µg/mL or 1 µg/mL respectively in 30 µg/mL of ZnO-NP\(_{20 nm}\) or 20 µg/mL of ZnO-NP\(_{100 nm}\) in FB. The addition of 1, 5, or 10 µg/mL ZnO-NP\(_{20 nm}\) or ZnO-NP\(_{100 nm}\) significantly reduced the clonogenic survival of FaDu after irradiation. The sub-cytotoxic dosage of ZnO-NP\(_{100 nm}\) increased the oxidative DNA damage compared to the irradiated control. This effect was not significant for ZnO-NP\(_{20 nm}\). ZnO-NP showed radiosensitizing properties in the sub-cytotoxic dosage. At least for the ZnO-NP\(_{100 nm}\), an increased level of oxidative stress is a possible mechanism of the radiosensitizing effect. KW - zinc oxide nanoparticles KW - irradiation KW - oxidative DNA damage KW - head and neck squamous cell carcinoma Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-193897 SN - 1996-1944 VL - 12 IS - 24 ER - TY - JOUR A1 - Meyer, Till Jasper A1 - Gerhard-Hartmann, Elena A1 - Lodes, Nina A1 - Scherzad, Agmal A1 - Hagen, Rudolf A1 - Steinke, Maria A1 - Hackenberg, Stephan T1 - Pilot study on the value of Raman spectroscopy in the entity assignment of salivary gland tumors JF - PLoS One N2 - Background The entity assignment of salivary gland tumors (SGT) based on histomorphology can be challenging. Raman spectroscopy has been applied to analyze differences in the molecular composition of tissues. The aim of this study was to evaluate the suitability of RS for entity assignment in SGT. Methods Raman data were collected in deparaffinized sections of pleomorphic adenomas (PA) and adenoid cystic carcinomas (ACC). Multivariate data and chemometric analysis were completed using the Unscrambler software. Results The Raman spectra detected in ACC samples were mostly assigned to nucleic acids, lipids, and amides. In a principal component-based linear discriminant analysis (LDA) 18 of 20 tumor samples were classified correctly. Conclusion In this proof of concept study, we show that a reliable SGT diagnosis based on LDA algorithm appears possible, despite variations in the entity-specific mean spectra. However, a standardized workflow for tissue sample preparation, measurement setup, and chemometric algorithms is essential to get reliable results. KW - Head and neck cancers KW - salivary gland tumors KW - salivary glands KW - cancers and neoplasms KW - malignant tumors KW - lipids KW - raman spectroscopy KW - surgical oncology Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-264736 VL - 16 IS - 9 ER - TY - JOUR A1 - Hackenberg, Stephan A1 - Meyer, Till Jasper A1 - Häfner, Johannes A1 - Scheich, Matthias A1 - Stöth, Manuel A1 - Al-Tinawi, Fadi A1 - Neun, Tilmann A1 - Mlynski, Robert A1 - Hagen, Rudolf A1 - Scherzad, Agmal T1 - Surgical management of tympanojugular paragangliomas using the flexible CO\(_2\) laser JF - European Archives of Oto-Rhino-Laryngology N2 - Purpose Surgery is a standard therapy for tympanojugular paragangliomas (TJP). Maintaining the quality of life (QoL) requires functional preservation. The flexible CO\(_2\) laser allows contact-free tumor removal. This retrospective study compares the postoperative functional outcomes of TJP surgery with and without the flexible CO\(_2\) laser. Methods Between 2005 and 2019, 51 patients with TJP were surgically treated at a tertiary hospital. Until 2012, 17 patients received conventional surgery. Thereafter, the flexible laser was used in 34 patients. Tumor extend, pre- and postoperative cranial nerve function, and complications were compared between the groups. Results The cohort consisted of 33 class A and B tumors and 18 class C and D tumors. Preoperative embolization was performed in 17 cases. Class C/D TJP were usually removed via an infratemporal fossa type A approach. Gross total tumor removal was achieved in 14/18 class C/D tumors. 3/51 patients suffered from long-term partial or complete facial palsy. No differences in post-therapeutic cranial nerve function or complications were noted between the conventional and laser group. One recurrence was observed after complete tumor resection. Conclusion The flexible CO\(_2\) laser was shown to be a safe and effective alternative to conventional bipolar cauterization, which is appreciated by the surgeon in these highly vascularized tumors. Both techniques allowed a high tumor control rate and good long-term results also from a functional point of view. KW - tympanojugular paraganglioma KW - tympanic paraganglioma KW - jugular paraganglioma KW - surgical management of paraganglioma KW - laser surgery KW - flexible CO2 laser Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324164 VL - 279 IS - 12 ER -