Oxygenation and response to irradiation of organotypic multicellular spheroids of human glioma.
OBJECTIVE
Investigation of the oxygenation status of organotypic multicellular spheroids (OMS) and their response to irradiation.


METHODS
Tumour specimens of glioblastoma multiforme patients (n = 16) were initiated as OMS. Following 20 Gy gamma-irradiation, the cell migratory capacity was evaluated. Spheroid oxygenation was determined by micro-electrode pO2 measurements and pimonidazole immunostaining. Spheroids prepared from established human glioma cell lines were used as a reference.


RESULTS
Irradiation inhibited spheroid outgrowth by 12 to 88% relative to the non-irradiated controls. A large interpatient variation was noticed. Oxygen measurements revealed a gradual decrease in pO2 level from the periphery to the core of the spheroids, but the pO2 values remained within an oxygenated range. However, in the cell line spheroids an intermediate layer of hypoxia surrounding the central core was observed.


CONCLUSIONS
Cell line spheroids with a hypoxic cell fraction and well-oxygenated OMS both show high resistance to irradiation, indicating that hypoxia may not be the biological factor determining the radioresistance of glioma spheroids in vitro.
Sminia
Peter
P
Department of Radiation Oncology, Section Radiobiology, VU Universtity Medical Center, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands. p.sminia@vumc.nl
Acker
Helmut
H
Eikesdal
Hans Petter
HP
Kaaijk
Patricia
P
Enger
Per øvind
Pø
Slotman
Ben
B
Bjerkvig
Rolf
R
D001932:Brain Neoplasms / Q000473:pathology*; D002455:Cell Division / Q000528:radiation effects; D015687:Cell Hypoxia; D002465:Cell Movement / Q000528:radiation effects; D018736:DNA Adducts / Q000032:analysis; D004273:DNA, Neoplasm / Q000032:analysis; D005720:Gamma Rays; D005909:Glioblastoma / Q000473:pathology*; D006801:Humans; D018613:Microscopy, Confocal; D009593:Nitroimidazoles / Q000494:pharmacology; D010100:Oxygen / Q000378:metabolism*; D010313:Partial Pressure; D011836:Radiation Tolerance; D018874:Spheroids, Cellular / Q000378:metabolism / Q000528:radiation effects*
D018736:DNA Adducts; D004273:DNA, Neoplasm; D009593:Nitroimidazoles; C033815:pimonidazole; D010100:Oxygen