52 research outputs found
Endoplasmic reticulum and Golgi apparatus are the preferential sites of Foscan® localisation in cultured tumour cells
Tumor necrosis factor alpha induces gamma-glutamyltransferase expression via nuclear factor-kappaB in cooperation with Sp1
Gamma-glutamyltransferase (GGT) cleaves the gamma-glutamyl moiety of glutathione (GSH), an endogenous antioxidant, and is involved in mercapturic acid metabolism and in cancer drug resistance when overexpressed. Moreover, GGT converts leukotriene (LT) C4 into LTD4 implicated in various inflammatory pathologies. So far the effect of inflammatory stimuli on regulation of GGT expression and activity remained to be addressed. We found that the proinflammatory cytokine tumor necrosis factor alpha (TNFalpha) induced GGT promoter transactivation, mRNA and protein synthesis, as well as enzymatic activity. Remicade, a clinically used anti-TNFalpha antibody, small interfering RNA (siRNA) against p50 and p65 nuclear factor-kappaB (NF-kappaB) isoforms, curcumin, a well characterized natural NF-kappaB inhibitor, as well as a dominant negative inhibitor of kappaB alpha (IkappaBalpha), prevented GGT activation at various levels, illustrating the involvement of this signaling pathway in TNFalpha-induced stimulation. Over-expression of receptor of TNFalpha-1 (TNFR1), TNFR-associated factor-2 (TRAF2), TNFR-1 associated death domain (TRADD), dominant negative (DN) IkappaBalpha or NF-kappaB p65 further confirmed GGT promoter activation via NF-kappaB. Linker insertion mutagenesis of 536 bp of the proximal GGT promoter revealed NF-kappaB and Sp1 binding sites at -110 and -78 relative to the transcription start site, responsible for basal GGT transcription. Mutation of the NF-kappaB site located at -110 additionally inhibited TNFalpha-induced promoter induction. Chromatin immunoprecipitation (ChIP) assays confirmed mutagenesis results and further demonstrated that TNFalpha treatment induced in vivo binding of both NF-kappaB and Sp1, explaining increased GGT expression, and led to RNA polymerase II recruitment under inflammatory conditions
Epicocconone, A New Cell-Permeable Long Stokes' Shift Fluorescent Stain for Live Cell Imaging and Multiplexing
Structure–Activity Relationship and Pharmacokinetic Studies of 1,5-Diheteroarylpenta-1,4-dien-3-ones: A Class of Promising Curcumin-Based Anticancer Agents
Enhanced Oral Bioavailability of Curcumin via a Solid Lipid-Based Self-Emulsifying Drug Delivery System Using a Spray-Drying Technique
Expression of VSTM1-v2 Is Increased in Peripheral Blood Mononuclear Cells from Patients with Rheumatoid Arthritis and Is Correlated with Disease Activity
Photochemical Internalization of Transgenes Controlled by the Heat-shock Protein 70 Promoter
Spectrum of Biological Activity of the Alternaria Fungi Isolated from the Phyllosphere of Herbaceous Plants
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