[Changes of protein and RNA content in accumulated G1 cells by delta12-PGJ2]

Protein and RNA content in accumulated G1 cells was measured with B16 melanoma cells by flow cytometer to study the mechanism of antineoplastic action of delta 12PGJ2. DNA histogram showed that, after a 6 hr exposure to delta 12PGJ2, the percentage of tumor cells in G2M phase increased, and G1 accumulation with depletion of cell population in S phase was seen after 12-24 hr exposure to 2.0 micrograms/ml of delta 12 PGJ2. Protein content in accumulated G1 cells increased at 6 hr after exposure, and subsequently decreased. However, the protein content treated with delta 12PGJ2 was higher than that of the control. A reduction of RNA content in G1 cells was seen after delta 12PGJ2 exposure. As the result, it was found that delta 12PGJ2 made cell progression ceased in G1 phase of cell cycle, and where protein and RNA content was higher than that of control. It is suggested that some hyper-metabolite state was caused by delta 12 PGJ2 in cultured B16 melanoma cells.