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Prostaglandin E2 signalling pathway in human T lymphocytes from healthy and conjunctiva basal cell carcinoma‐bearing subjects
Author(s) -
Venza I,
Giordano L,
Piraino G,
Medici N,
Ceci G,
Teti D
Publication year - 2001
Publication title -
immunology and cell biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.999
H-Index - 104
eISSN - 1440-1711
pISSN - 0818-9641
DOI - 10.1046/j.1440-1711.2001.01034.x
Subject(s) - creb , phosphorylation , creb binding protein , protein kinase a , activator (genetics) , signal transduction , creb1 , cancer research , biology , microbiology and biotechnology , protein kinase c , prostaglandin e2 receptor , prostaglandin e2 , endocrinology , medicine , receptor , biochemistry , transcription factor , gene , agonist
Prostaglandin E‐induced signal transduction pathways in human T cells from healthy and uveal melanoma‐bearing subjects were studied. Transfection experiments showed that PGE2 was able to phosphorylate and activate the fusion trans‐activator of the cAMP responsive element‐binding protein (CREB). Phosphorylation was at least partially mediated by protein kinase A, as evidenced by the effects of specific kinase inhibitors. Western blotting experiments, which were performed to identify the CREB/ATF2 family members involved in the response to PGE2, revealed a modulation of proteins CREB1, CREB2 and ATF2 and phosphorylation of the 43 kDa form of CREB. Experiments of immunoprecipitation with CREB‐binding protein (CBP) demonstrated that, after PGE2 treatment, all of the CREB/ATF isoforms studied, as well as the phosphorylated form of CREB (p‐CREB), interacted with CBP. In basal conditions, T cells from patients with conjunctiva basal cell carcinoma showed the presence of p‐CREB, which coimmunoprecipitated with CBP. CREB phosphorylation did not modify after PGE2 treatment whereas the p‐CREB fraction bound to CBP increased in a delayed manner compared to normal subjects.