Journal: Cancers
Article Title: EF-24, a Curcumin Analog, Inhibits Cancer Cell Invasion in Human Nasopharyngeal Carcinoma through Transcriptional Suppression of Matrix Metalloproteinase-9 Gene Expression
doi: 10.3390/cancers15051552
Figure Lengend Snippet: EF-24 suppresses MMP-9 gene transcription by interfering with nuclear translocation of NF-κB. HONE-1 cells expressing a luciferase gene driven by wild-type ( A ) and various mutated forms ( B – E ) of MMP-9 promoter were pretreated with EF-24 for 1 h and then incubated with TPA for an additional 23 h. Luciferase assays were used to measure the transcriptional activity of MMP-9 promoter. Schematic representations of the reporter plasmids containing a mutated SP-1 ( B ), AP-1 ( C , D ), or NF-κB responsive element ( E ) are shown on the top. To explore the nuclear translocation of NF-κB, a nuclear extract of untransfected HONE-1 cells after the treatment of EF-24 and TPA was isolated and analyzed for the protein levels of NF-κB ( F ). Blots are representative of three independent experiments. Densitometric analyses were conducted by ImageJ, and quantitative results were normalized to the nuclear levels of an internal control, lamin B2. In addition, HONE-1 cells treated with EF-24 and TPA were fixed and stained with DAPI and a specific antibody against NF-κB p65 ( G ). The interaction of NF-κB with MMP-9 promoter was analyzed by using chromatin immunoprecipitation assay (ChIP) with an NF-κB antibody in HONE-1 cells treated with or without NF-24 and TPA ( H ). Densitometric analyses were conducted by ImageJ. a Significantly different, p < 0.05, when compared with the control group. b Significantly different, p < 0.05, when compared with the TPA treatment group. c Significantly different, p < 0.05, when compared with the TPA treatment plus EF-24 (0.25 μM) group. d Significantly different, p < 0.05, when compared with the TPA treatment plus EF-24 (0.5 μM) group.
Article Snippet: The constructs containing NF-κB-Luc, SP-1-Luc, or AP-1-Luc sequences were obtained from Stratagene (La Jolla, CA, USA).
Techniques: Translocation Assay, Expressing, Luciferase, Incubation, Activity Assay, Isolation, Staining, Chromatin Immunoprecipitation