CALCIUM MOBILIZATION DURING NICOTINE-INDUCED CELL-DEATH IN HUMAN GLIOMA AND GLIOBLASTOMA CELL-LINES

Nicotine dose-dependently induced cytotoxicity in human glioma (KG-I-C ) and glioblastoma (GBS-I, T98G) cell lines, but could not induce inte rnucleosomal DNA cleavage, in contrast to apoptosing human myelogenous leukemic cell lines. Human glioma/glioblastoma cell lines thus might have a chromatin structure resistant to endonuclease digestion. Nicoti ne induced a rapid increase in the intracellular calcium concentration . Confocal experiments with Fluo-3 fluorescence revealed that nicotine elevated the free Ca2+ concentration in both nuclear and cytoplasmic regions of the cells, and the elevation of Ca2+ in the nuclear region was more pronounced than that of the cytoplasmic region. The present s tudy suggests that nuclear accumulation of Ca2+ is an important initia l step for cell death induction by nicotine.