gms | German Medical Science

73. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
Joint Meeting mit der Griechischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

29.05. - 01.06.2022, Köln

Correlative biomechanical and biochemical analysis of glioblastoma cell cultures using brillouin and raman spectroscopy

Korrelative biomechanische und biochemische Analyse von Glioblastomzellkulturen mittels Brillouin- und Ramanspektroskopie

Meeting Abstract

  • presenting/speaker Jan Rix - Technische Universität Dresden, Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Carl Gustav Carus, Dresden, Deutschland
  • Ortrud Uckermann - Carl Gustav Carus Universitätsklinikum, TU Dresden, Klinik und Poliklinik für Neurochirurgie, Dresden, Deutschland; Technische Universität Dresden, Division of Medical Biology, Department of Psychiatry, Faculty of Medicine and University Hospital Carl Gustav Carus, Dresden, Deutschland
  • Katrin Kirsche - Carl Gustav Carus Universitätsklinikum, TU Dresden, Klinik und Poliklinik für Neurochirurgie, Dresden, Deutschland
  • Gabriele Schackert - Carl Gustav Carus Universitätsklinikum, TU Dresden, Klinik und Poliklinik für Neurochirurgie, Dresden, Deutschland
  • Edmund Koch - Technische Universität Dresden, Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Carl Gustav Carus, Dresden, Deutschland
  • Matthias Kirsch - Carl Gustav Carus Universitätsklinikum, TU Dresden, Klinik und Poliklinik für Neurochirurgie, Dresden, Deutschland; Asklepios Kliniken Schildautal, Klinik für Neurochirurgie, Seesen, Deutschland; National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Deutschland
  • Roberta Galli - Technische Universität Dresden, Department of Medical Physics and Biomedical Engineering, Faculty of Medicine Carl Gustav Carus, Dresden, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 73. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Griechischen Gesellschaft für Neurochirurgie. Köln, 29.05.-01.06.2022. Düsseldorf: German Medical Science GMS Publishing House; 2022. DocP004

doi: 10.3205/22dgnc320, urn:nbn:de:0183-22dgnc3205

Published: May 25, 2022

© 2022 Rix et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

Text

Objective: Biomechanics of tumor cells influence proliferation, migration and metastasis of brain tumor cells. So far, the measurement of cell stiffness in tumor models has been limited to cell surface measurements due to the use of contact-based techniques such as AFM. Here, we overcome this limit by using optical Brillouin spectroscopy to perform subcellular investigation of cell compartments in adherent cells and spheroid cultures of glioblastoma. We correlated biomechanical with biochemical information obtained from simultaneous and co-localized Raman spectroscopy for interpreting stiffness changes.

Methods: U87-MG cells were cultured as adherent cells (n=11) and spheroids (n=9). Additionally, five primary glioblastoma cell lines were analyzed (each cell line n=10-12). Brillouin and Raman spectroscopy was performed in a combined setup using 780 nm excitation wavelength. The Brillouin shift, which provides information about the stiffness, was computed by fitting each of the 2500 single measurements per sample with Lorentzian functions. Raman spectra in the range 700-1800 cm-1 were baseline corrected, normalized and analyzed by k-means clustering.

Results: U87-MG adherent cells showed smaller Brillouin shifts and values displayed a higher variability compared to spheroids (5.319 ± 0.033 GHz vs. 5.408 ± 0.015 GHz, mean ± SD, n=11 and 9, unpaired t-test p<0.001). Cluster analysis of Raman spectra of adherent cells was used to identify cell compartments. Nucleus, perinuclear region and cytoplasm exhibited different mean Brillouin shifts (5.33 GHz, 5.29 GHz and 5.23 GHz, respectively), thus indicating that the stiffness of nucleus is highest. For spheroids, larger Brillouin shifts were retrieved in regions with high content of proteins (identified by Raman bands at 1006 and 1607 cm-1) as well as of lipids (Raman bands at 1440 and 1750 cm-1). Also in primary cell lines the Brillouin shift correlated with the amount of lipid droplets.

Conclusion: Adherent cells and cell spheroids have different biomechanical properties, which are driven by culturing methods and can be explained at subcellular level by different biochemical composition. Brillouin spectroscopy of cell spheroids delivers more reproducible results, but the Brillouin shift is highly sensitive to lipid content in the cells. Further analysis shall clarify by which mechanisms the lipids exactly induce the apparent stiffness increase and how this relates to tumor properties.