IN-VITRO ASSESSMENT OF TAXOL FOR HUMAN GLIOBLASTOMA - CHEMOSENSITIVITY AND CELLULAR LOCOMOTION

Although the antineoplastic efficacy of Taxol against a variety of tum ors has been established, it has only recently been used for malignant brain tumors. We evaluated in vitro chemosensitivity of glioblastoma to Taxol and the affect of Taxol on glioblastoma cell locomotion. The clonogenic assay was used to evaluate the chemosensitivity of five hum an glioblastomas and the C6 rat glioma. Cells exposed to Taxol (0-250 nM) were suspended in agar in capillary tubes. Following incubation, c olonies were counted to determine percent survival. All six cell lines demonstrated sensitivity to Taxol (LD(50) 1 nM to >250 nM). However, even at concentrations exceeding those achievable clinically, all cell lines had surviving cells, indicating a saturation threshold far Taxo l cytotoxicity. Cell locomotion was evaluated using the radial dish as say to determine the rate of egress of cells from a region of high cel l density to the periphery. Increasing Taxol concentration caused incr eased locomotion in all six cell lines (p < 0.0001). Although Taxol ha s significant cytocidal impact, it increases in vitro locomotion of gl ioblastoma cells. These findings suggest that the clinical use of Taxo l for glioblastoma may slow the growth of bulk disease, but may also l ead to increased tumor invasion.