Development of a three-dimensional in vitro model for longitudinal observation of cell behavior: monitoring by magnetic resonance imaging and optical imaging.
OBJECTIVE
The aim of this study is the development of a three-dimensional multicellular spheroid cell culture model for the longitudinal comparative and large-scale screening of cancer cell proliferation with noninvasive molecular imaging techniques under controlled and quantifiable conditions.


METHODS
The human glioblastoma cell line Gli36DeltaEGFR was genetically modified to constitutively express the fluorescence protein mCherry, and additionally labeled with iron oxide nanoparticles for high-field MRI detection. The proliferation of aggregates was longitudinally monitored with fluorescence imaging and correlated with aggregate size by light microscopy, while MRI measurements served localization in 3D space. Irradiation with gamma-rays was used to detect proliferational response.


RESULTS
Cell proliferation in the stationary three-dimensional model can be observed over days with high accuracy. A linear relationship of fluorescence intensity with cell aggregate size was found, allowing absolute quantitation of cells in a wide range of cell amounts. Glioblastoma cells showed pronounced suppression of proliferation for several days following high-dose gamma-irradiation.


CONCLUSIONS
Through the combination of two-dimensional optical imaging and 3D MRI, the position of individual cell aggregates and their corresponding light emission can be detected. This allows an exact quantification of cell proliferation, with a focus on very small cell amounts (below 100 cells) using high resolution noninvasive techniques as a well-controlled basis for further cell transplantation studies.
Kruttwig
Klaus
K
In-vivo-NMR-Laboratory, Max-Planck-Institute for Neurological Research, Gleuelerstrasse 50, 50931 Cologne, Germany.
Brueggemann
Chantal
C
Kaijzel
Eric
E
Vorhagen
Susanne
S
Hilger
Thomas
T
Löwik
Clemens
C
Hoehn
Mathias
M
D002449:Cell Aggregation; D002452:Cell Count; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D003911:Dextrans; D052203:Ferrosoferric Oxide / Q000378:metabolism; D005453:Fluorescence; D005720:Gamma Rays; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D008954:Models, Biological; D057054:Molecular Imaging / Q000379:methods*; D055620:Optical Phenomena; D013194:Staining and Labeling
D003911:Dextrans; D058185:Magnetite Nanoparticles; C065507:ferumoxides; D052203:Ferrosoferric Oxide