Invasion of human glioma biopsy specimens in cultures of rodent brain slices: a quantitative analysis.
OBJECTIVE
The reliable assessment of the invasiveness of gliomas in vitro has proved elusive, because most invasion assays inadequately model in vivo invasion in its complexity. Recently, organotypical brain cultures were successfully used in short-term invasion studies on glioma cell lines. In this paper the authors report that the invasiveness of human glioma biopsy specimens directly implanted into rodent brain slices by using the intraslice implantation system (ISIS) can be quantified with precision. The model was first validated by the demonstration that, in long-term studies, established glioma cells survive in the ISIS and follow pathways of invasion similar to those in vivo.


METHODS
Brain slices (400 microm thick) from newborn mice were maintained on millicell membranes for 15 days. Cells from two human and one rodent glioblastoma multiforme (GBM) cell lines injected into the ISIS were detected by immunohistochemistry or after transfection with green fluorescent protein-containing vectors. Preferential migration along blood vessels was identified using confocal and fluorescent microscopy. Freshly isolated (< or = 24 hours after removal) 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate-prelabeled human glioma biopsy specimens were successfully implanted in 19 (83%) of 23 cases, including 12 GBMs and seven lower grade gliomas (LGGs). Morphometric quantification of distance and density of tumor cell invasion showed that the GBMs were two to four times more invasive than the LGGs. Heterogeneity of invasion was also observed among GBMs and LGGs. Directly implanted glioma fragments were more invasive than spheroids derived from the same biopsy specimen.


CONCLUSIONS
The ISIS combines a high success rate, technical simplicity, and detailed quantitative measurements and may, therefore, be used to study the invasiveness of biopsy specimens of gliomas of different grades.
Institut Nationale de la Santé et de la Recherche Médicale, Unité 421, Faculté de Médecine, Créteil, France.
Sophie
S
de Boüard
Christo
C
Christov
Jean-Sébastien
JS
Guillamo
Lina
L
Kassar-Duchossoy
Stéphane
S
Palfi
Caroline
C
Leguerinel
Michel
M
Masset
Odile
O
Cohen-Hagenauer
Marc
M
Peschanski
Thierry
T
Lefrançois
D000818:Animals; D001706:Biopsy; D001932:Brain Neoplasms / Q000473:pathology*; D003584:Cytological Techniques; D005910:Glioma / Q000473:pathology*; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D009361:Neoplasm Invasiveness / Q000473:pathology*; D009924:Organ Culture Techniques; D014407:Tumor Cells, Cultured