INTRACELLULAR-DISTRIBUTION OF POLYAMINES IN HUMAN LYMPHOBLASTOID CELL-LINE DURING PHORBOL ESTER-INDUCED DIFFERENTIATION

Polyamines such as putrescine, spermidine and spermine play an importa nt role in nucleic acid metabolism. These aliphatic amines display a k ey role in cell-induced transformation by carcinogenic substances. In particular, one of these, the phorbol myristate acetate, provokes cell differentiation and gives an increase of ornithindecarboxylase activi ty; enzyme regulating the pathways of polyamines. In this study we ana lyse the trend of the polyamines at cytoplasmic and nuclear level duri ng phorbol treatment. Our results show a correlation between nuclear a nd cytoplasmic spermine, H-3-Thymidine, H-3-Leucine incorporation and cell cycle phases. These data remark that the polyamines are different ly distributed into the cell during the phorbol myristate acetate-medi ated differentiation process and that the spermine is down-regulated f or to supply the increased protein biosynthesis.