ISOLATION AND CHARACTERIZATION OF HUMAN-MALIGNANT GLIOMA-CELLS FROM HISTOLOGICALLY NORMAL BRAIN

Brain invasion prevents complete surgical extirpation of malignant gli omas; however, invasive cells from distant, histologically normal brai n previously have not been isolated, cultured, and characterized. To e valuate invasive human malignant glioma cells, the authors established cultures from gross tumor and histologically normal brain. Three men and one woman, with a mean age of 67 years, underwent two frontal and two temporal lobectomies for tumors, which yielded specimens of both g ross tumor and histologically normal brain. Each specimen was acquired a minimum of 4 cm from the gross tumor. The specimens were split: a p ortion was sent for neuropathological evaluation (three glioblastomas multiforme and one oligodendroglioma) and a portion was used to establ ish cell lines. Morphologically, the specimens of gross tumor and hist ologically normal brain were identical in three of the four cell cultu re pairs. Histochemical staining characteristics were consistent both within each pair and when compared with the specimens sent for neuropa thological evaluation. Cultures demonstrated anchorage-independent gro wth in soft agarose and neoplastic karyotypes. Growth rates in culture were greater for histologically normal brain than for gross tumor in three of the four culture pairs. Although the observed increases in gr owth rates of histologically normal brain cultures do pot correlate wi th in vivo behavior, these findings corroborate the previously reporte d stem cell potential of invasive glioma cells. Using the radial dish assay, no significant differences in motility between cultures of gros s tumor and histologically normal brain were found. In summary, tumor cells were cultured from histologically normal brain acquired from a d istance greater than 4 cm from the gross tumor, indicating the relativ e insensitivity of standard histopathological identification of invasi ve glioma cells (and hence the inadequacy of frozen-section evaluation of resection margins). Cell lines derived from gross tumor and histol ogically normal brain were usually histologically identical and demons trated equivalent motility, but had different growth rates.