Inhibition of DNA synthesis in human gliomas by roscovitine

THE early effect of 1–100 μM roscovitine, a purine analogue and cyclin-dependent kinase inhibitor, was studied on tissue specimens from eight human malignant gliomas. The tissue was incubated immediately after resection with DMEM containing [H]methylthymidine plus vehicle alone or the proper concentration of roscovitine for 30–90 min. The DNA synthesis rate was assessed by measurement of [H]methylthymidine incorporation into trichloroacetic acid insoluble material/mg protein/min. In all gliomas, 100 μM roscovitine inhibited DNA synthesis by 71–97% (average 89 ± 8%, p