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Abstract #26974 Published in IGR 12-4
Potentiation of Bortezomib-Induced Apoptosis by TGF-{beta} in Cultured Human Tenon's Fibroblasts: Contribution of the PI3K/Akt Signaling Pathway.
Chung EJ; Moon SW; Jung SA; Cho YJ; Kim SW; Lee JHInvestigative Ophthalmology and Visual Science 2010; 51: 6232-6237
Purpose. To investigate the effects of bortezomib on cell apoptosis and proliferation in human Tenon's capsule fibroblasts (HTFs) after cotreatment with TGF-β. Methods. The effect of bortezomib on the apoptosis and cell proliferation of cultured HTFs was determined with FACS analysis and 3-[4,5-demethylthiazol-2,5-diphenyl-2H-tetrazolium bromide] (MTT) assay with or without cotreatment of TGF-β. The apoptotic effect of cotreatment of bortezomib and TGF-β through the PI3K/Akt pathway was determined by Western blot analysis. The mRNA level of Bcl-2 and Bax was determined by RT-PCR. p53 expression, DNA-PKcs cleavage, and c-Jun phosphorylation were determined. Results. Cotreatment with bortezomib (5 μM) and TGF-β (10 μM) increased the proportion of apoptotic cells in HTFs on FACS analysis, whereas either bortezomib or TGF-β treatment alone did not. The MTT assay also showed that when bortezomib was cotreated with TGF-β, the cell proliferation of HTFs induced by TGF-β treatment was significantly decreased at 72-hour incubation. The cotreatment of bortezomib and TGF-β specifically decreased the Akt phosphorylation induced by TGF-β, indicating on Western blot analysis that these changes are mediated by the PI3K/Akt pathway. The mRNA level of an apoptosis-related factor, Bcl-2, was significantly reduced, and p53 expression, DNA-PKcs cleavage, and c-Jun phosphorylation were increased after cotreatment. Conclusions. Bortezomib-induced apoptosis is potentiated by TGF-β cotreatment in cultured HTFs by inhibition of the PI3K/Akt pathway, indicating that the effect of bortezomib may be potentiated when the level of TGF-β is elevated, as is observed in the postoperative period.
Department of Ophthalmology, National Health Insurance Corporation Ilsan Hospital, Gyounggi-do, Korea;
Classification:
11.14 Investigational drugs; pharmacological experiments (Part of: 11 Medical treatment)
12.8.10 Woundhealing antifibrosis (Part of: 12 Surgical treatment > 12.8 Filtering surgery)