Transformation by radiation of rat foetal glial cells.

Purpose: To establish and characterize an in vitro model of radiation-induced transformation of normal glial cells.

Materials And Methods: During the last week of gestation, pregnant Sprague-Dawley rats were either irradiated at 3.5 Gy (0.

Purine metabolism in two human melanoma cell lines: relation to proliferation and differentiation.

Purine nucleotide metabolism was studied in two human cutaneous melanoma cell lines IPC182 and IGR221. IPC182 cells do not differentiate, while IGR221 cells differentiate spontaneously at confluency, with intense melanin production. The activities of 11 enzymes involved in the de novo or salvage synthesis or the catabolic pathway of purine nucleotides were measured at different times (from day 3 to day 18), after subculture, during exponential growth and the stationary phase, with or without differentiation.

Modifications of the antioxidant enzymes in relation to chromosome imbalances in human melanoma cell lines.

Five human melanoma cell lines were investigated for their antioxidant activities. These metabolic data were correlated with cytogenetic analysis giving the relative numbers of chromosomes or chromosomal segments carrying the gene encoding for each enzyme. Particular attention was focused on the expression of superoxide dismutase 2 (SOD2), whose gene, located on the long arm of chromosome 6 (6q), has been proposed as a tumour suppressor gene.

[Nucleotide metabolism in human glioma: comparative study of primary tumors, grafted tumors on nude mice and cell cultures].

A study developed to test the hypothesis of a possible relationship between metabolic modifications and chromosomal imbalances in solid tumors leads us to investigate the metabolism of purine nucleotides in human gliomas. In order to assess the representativeness of experimental models frequently used, the activities of nine enzymes involved in the synthesis and in the catabolism of purine nucleotides were measured on samples of normal brain, primary and xenografted glial tumors and cell cultures established from human gliomas. In parallel, two enzymes involved in pyrimidine metabolism were also studied on the same samples.

Establishment and characterization of human ocular melanoma cell lines.

Five continuous cell lines have been established from 29 ocular melanomas and maintained for periods ranging from 3 to 9 years in medium identical to that in which 3 concomitantly studied lines of cutaneous melanoma cells were cultured as controls. The long-term problems to be overcome in establishing uveal cell lines are related to cell-doubling times which ranged from 72 to 432 hr, and plating efficiency, which ranged from 0.5%-6.