Fig. 1.

hENT1 and dCK expression and gemcitabine sensitivity in cultured meningioma cells. (A) Viability of cells treated with gemcitabine. IMR90 (a noncancerous, normal human fetal fibroblast cell line), M-20-U, M-10-S (low-grade meningioma cell lines), M-16-N, HKBMM, and IOMM-Lee (high-grade meningioma cell lines) cells treated with various concentrations of gemcitabine (0, 1, 10, 10², 10³, or 10⁴ nM) for 3 days were cultured without gemcitabine for another 3 days. Cell viability was then evaluated by the WST-8 assay in 5 replicates. IC₅₀ values were calculated by a nonlinear regression model. (B) Systemic administration of gemcitabine inhibits the growth of IOMM-Lee xenografts. On the day after the subcutaneous implantation of IOMM-Lee cells, mice were treated with gemcitabine (20 mg/kg, intraperitoneal injection, three times a week, n = 6) or vehicle alone (Control, n = 6). (C) The relationship between the IC₅₀ for gemcitabine and the expression of hENT1 and dCK was analyzed by Western blotting. Values in (A) and (B) are shown as the mean ± SD. *P < .05. Abbreviations: dCK, deoxycytidine kinase; hENT1, human equilibrative nucleoside transporter 1, NA, not applicable.