The effect of FK506 on transforming growth factor beta signaling and apaptosis in chronic lymphocytic leukemia B cells(132 visite) Romano S, Mallardo M, Chiurazzi F, Bisogni R, D'Angelillo A, Liuzzi R, Compare G, Romano MF
Impact factor: 5.978, Impact factor a 5 anni: 5.513
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Background Loss of response to transforming growth factor-beta (TGF-beta) is thought to contribute to the progression of chronic lymphocytic leukemia. Recent findings of over-activation of the TGF-beta signal in FKBP12-knockout mouse prompted us to investigate whether FK506, the canonical ligand of FKBP, can activate the TGF-beta signal in chronic lymphocytic leukemia. Design and Methods We studied 62 chronic lymphocytic leukemia samples from patients with Rai/Binet stage 0 to 4 disease. The TGF-beta signal was investigated by western blotting and flow cytometry. The levels of Bcl2-family members and death-associated-protein kinase were also investigated by western blotting, whereas apoptosis was studied in flow cytometry. Down-modulation of FKBP12 was obtained by gene silencing with short interfering RNA. Results Twenty-two out of 62 chronic lymphocytic leukemia samples were sensitive to TGF-beta-induced apoptosis. All but two of the responsive samples underwent apoptosis also when cultured with FK506, but not with cyclosporine. Thirteen samples that were not sensitive to TGF-beta were sensitive to FK506. Overall, response to FK506 occurred in 33 samples. FK506 induced Smad2 phosphorylation and nuclear translocation. Accordingly, death-associated-protein kinase, a transcriptional target of Smad, was induced. At the same time, Bcl-2 and Bcl-xL levels decreased whereas the levels of Bim and Bmf increased. A loss of mitochondrial membrane potential preceded caspase activation and cell death. FK506 removed FKBP12 from its binding to the TGF-beta-receptor. FKBP12 release activated the receptor-kinase activity as suggested by the enhanced levels of phospho-Smad found in cells depleted of FKBP12. Conclusions Our study shows that most chronic lymphocytic leukemia cells escape the homeostatic control of TGF-beta and that FK506 restores the TGF-beta signal in a proportion of non-responsive samples. We demonstrated that FK506 activates TGF-beta receptor I kinase activity in chronic lymphocytic leukemia, which transduces apoptosis by a mitochondrial-dependent pathway.
Petraglia F, Singh AA, Carafa V, Nebbioso A, Conte M, Scisciola L, Valente S, Baldi A, Mandoli A, Petrizzi VB, Ingenito C, De Falco S, Cicatiello V, Apicella I, Janssen-megens EM, Kim B, Yi G, Logie C, Heath S, Ruvo M, Wierenga ATJ, Flicek P, Yaspo ML, Della Valle V, Bernard O, Tomassi S, Novellino E, Feoli A, Sbardella G, Gut I, Vellenga E, Stunnenberg HG, Mai A, Martens JHA, Altucci L * Combined HAT/EZH2 modulation leads to cancer-selective cell death(78 visite) Oncotarget (ISSN: 1949-2553electronic, 1949-2553linking), 2018 May 22; 9(39): 25630-25646. Impact Factor:5.008 DettagliEsporta in BibTeXEsporta in EndNote
90 Records (82 escludendo Abstract e Conferenze). Impact factor totale: 391.065 (352.056 escludendo Abstract e Conferenze). Impact factor a 5 anni totale: 389.267 (350.333 escludendo Abstract e Conferenze).