The effect of methylmercuric chloride (CH3HgCl) on high affinity uptake of certain putative neurotransmitters on mouse neuroblastoma (NBE-) and rat glioma (C-6) cells in culture 3 days after treatment was studied. The energydependent accumulation of radioactive choline was decreased in NB cells afte treatment with CH3HgCl (1 μm), whereas the accumulation of radioactive glycine or glutamate was increased. The uptake of radioactive glycine or glutamate in glioma cells was decreased after treatment with CH3HgCl (0.3 μM). High affinity uptake of choline was not demonstrable in glioma cells. Low concentrations of CH3HgCl affect the accumulation of glycine and glutamate in glioma and NB cells in an opposite manner. © 1979.

The binding of radioactive methylmercuric chloride ([203Hg] -CH3HgCl) with various subcellular fractions of glioma (C-6) and neuroblastoma (NBP2) cells was studied. Confluent cells were incubated in the presence of radioactive CH3HgCl for a period of 5 h, and then various fractions were isolated. Most of the radioactivity was associated with the cytosol and particulate fractions. The cytosol and lipoprotein fractions of glioma cells incorporated more radioactive CH3HgCl than those of NB cells. The specific radioactivities of the particulate, lipid and chromatin fractions were comparable in both cell types. © 1979.

The amount of polyadenylic acid [poly(A)]-containing cytoplasmic RNA in malignant and 'differentiated' mouse neuroblastoma cells in culture was determined. 4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone (R020-1724), prostaglandin (PG)E1, serum-free medium, X-irradiation and sodium butyrate were used to induce 'differentiation'. The cAMP-induced 'differentiated' cells had more poly(A)-containing cytoplasmic RNA than the malignant cells; the increase in poly-(A)-RNA was greatest in R020-1724-treated cells. The amount of poly(A)-containing cytoplasmic RNA did not significantly change in serum-free medium- or sodium butyrate-treated cells; however, it decreased in cells of confluent phase of growth. The percentage of total radioactive RNA in the cytoplasms of cAMP-induced 'differentiated' cells after 1 h of labeling was three-fold greater than that in malignant cells, indicating that transport of RNA from nucleus to cytoplasm occurs at relatively higher rate in 'differentiated' cells. The stability of RNA in cAMP-induced 'differentiated' cells increased in comparison to malignant cells. The binding of actinomycin D with DNA suggests that the proportion of guanine residues that are accessible to actinomycin D are similar in the nuclei of malignant and cAMP-induced 'differentiated' cells. The present and previous studies suggest that cAMP induces many differentiated functions in neuroblastoma cells by increasing both the transcription and translation of genetic information which is probably masked during malignant transformation of nerve cells. © 1975.