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Dual effect of the phorbol ester TPA on arachidonic acid release from HeLa cells
Author(s) -
Kaszkin M.,
Espe U.,
Fu¨rstenberger G.,
Kinzel V.
Publication year - 1988
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(88)80435-6
Subject(s) - phorbol ester , arachidonic acid , hela , chemistry , biochemistry , protein kinase c , cell , signal transduction , enzyme
The tumor promoter 12‐ O ‐tetradecanoylphorbol 13‐acetate (TPA) induces release of arachidonic acid (AA) from HeLa cells with a maximum at 2–3 h. Subsequently the extracellular level of AA decreases. Cycloheximide (CH, 10 −5 M) does not influence the release of AA, however, it causes the AA level to remain elevated. In the presence of TPA and CH (i) re‐uptake of AA is not altered, (ii) re‐incorporation of AA into phosphatidylinositol (and phosphatidylethanolamine) is largely increased, and (iii) the level of lysophosphatidylinositol is elevated. The latter two phenomena can be prevented by fluocinolone acetonide (10 −8 M), i.e. by inhibition of phospholipase A 2 (PLA 2 ). These data point to a continuously elevated PLA 2 activity in the presence of TPA and CH. The phorbol ester appears to induce a proteinaceous principle which diminishes PLA 2 activity.