Differential sensitivities of glioma cells and neuroblastoma cells to methylmercury toxicity in cultures

Effects of methylmercuric chloride on high affinity uptake of certain putative neurotransmitters in neuroblastoma and glioma cell cultures

“…Fresh growth medium (3 ml) without CH 3 HgCl was added 30 min prior to the addition of radioactive putative neurotransmitters. In view of the greater sensitivity of glial cells to CH 3 HgCl [9], they were cultured at a concentration of 0.3 · 10-6 M while NB cells were grown in 10-6 M. 10 µl of radioactive compounds containing 0.5 µCi were then added to the dishes. Final µM concentrations of each compound used were L- [2, The culture dishes were incubated at 37°C for 10 min while identically prepared dishes were maintained at 0°C for 10 min.…”

“…In vitro concentrations of 0.3 µM-1.0 µM CH 3 HgCI produce disturbances in high affinity uptake of certain putative neurotransmitters. Previous shortterm studies have shown [9][10][11][12] that these concentrations of CH 3 HgCl inhibit cell division and increase the intracellular level of cyclic AMP in glioma and NB cells. Long-term treatment of glioma and NB cells with lower concentrations of CH 3 HgCI (0.05-0.2 µM) produces marked alteration in gene expression as evidenced by changes in the amount and phosphorylation of specific proteins [12,13], and reduces the sensitivity of adenylate cyclase to prostaglandin E 1 in glioma cells, but not in NB cells [11].…”

“…Although these cells are of tumor origin, and represent proliferative systems, they exhibit many features of mature glial cells and neurons, respectively. Previous studies have shown that: (a) glioma cells are more sensitive to CH 3 HgCl than NB cells for the criteria of cell death and inhibition of cell division [9]; (b) the intracellular level of cyclic AMP increases after treatment of glioma (0.3 µM) and NB cells (1 µM) with CH 3 HgCl [10); (c) long-term treatment of glioma and NB cells with low concentrations of CH 3 HgCl (0.1 µM) reduces the sensitivity of adenylate cyclase to prostaglandin E 1 in glioma cells, but not in NB cells [11], and produces marked alterations in gene expression in glioma cells and NB cells [12][13]. We now report that the treatment of glioma and NB cells with CH 3 HgCl affects the uptake of certain putative neurotransmitters in a different way.…”

Binding of radioactive methylmercuric chloride in subcellular fractions of neuroblastoma and glioma cells in culture

“…Neuroblastoma cells are grown in F12 medium containing 10% agammaglobulin newborn calf serum, whereas glioma cells are grown in MEM containing 10% fetal calf serum [8]. The growth media also contain penicillin (100 U/ml) and streptomycin (100 µg/ml).…”

“…We are currently using cultures of rat glioma (C-6) and mouse NB cells as model systems to examine the cellular and molecular basis of CH 3 HgCl-induced damages to the nervous tissue. We have shown that the glioma cells are much more sensitive to CH 3 HgCl than NB cells on the criteria of inhibition of cell division and cell death [8]. In order to understand the cellular and molecular mechanisms of the effects of CH 3 HgCl, knowledge of cellular localization and binding of CH 3 HgCl with various subcellular fractions is important.…”