Project description:Tet-on and tet-off systems are among the most popular vector systems for inducible transgene expression in mammalian cells. In tet-regulated systems the expression of the transgene depends on the presence or absence of the antibiotic tetracycline or its derivative doxycycline, which are added to the cell culture medium in concentrations considered to be far below cytotoxic levels. Therefore, potential effects on the treated cells, which are exerted by the antibiotic itself and unrelated to transgene expression, are often ignored. We examined the influence of low dose doxycycline on the transcriptional profile of two independent clones of MCF7 human breast carcinoma cells, transfected with tet-off regulator and response plasmids but not harboring any transgene. Treatment with 80 ng/ml doxycycline for 12 days markedly altered gene expression in these cells. Many genes associated with interferon-signaling were up-regulated while cell cycle-associated genes were down-regulated, which was also accompanied by a reduction of cell growth. These results highlight the importance of appropriate controls when working with tet-regulated gene expression systems, to allow distinction between the effects of transgene expression and potential “side effects” of the antibiotic used for its regulation.
Project description:To identify the target of miR-212, miR-132 and HIC1, we have employed whole genome microarray expression profiling on the human breast cancer MCF7 cells. To generate miR-212/132 or HIC1 inducible MCF7 cells, doxycycline-dependent miR-212/132 or HIC1 gene expression system was used. Either Tet-ON miR-212/132 MCF7 or Tet-ON HIC1 MCF7 were treated with 1μg/ml of Doxycycline for 36 hours with EMEM containing 0.01 mg/ml bovine insulin and 10% FCS. Two independent experiments were performed.
Project description:MCF7 and MDA-MB-231 breast cancer cell lines were cultured in DMEM-F12 containing 10% FBS (Lonza) 100U/ml penicillin and 100 µg/ml streptomycin (Lonza). Transfecting third generation packaging vectors using Poly-ethylenimine into HEK293T cells generated lentiviral particles (17). MCF7 and MDA-MB-231 cells were stably transduced with lentivirus containing pINDUCER20-FOXO3.A3, allowing doxycycline induced expression of constitutively active FOXO3 (FOXO3.A3). Cells were treated with 20% FBS or 10 µM PI3K inhibitor LY294002 (Selleckchem) for 16 hours to activate and inactivate the endogenous PI3K pathway, respectively. FOXO3.A3 expression was induced by 16 hours treatment with 10 ng/ml doxycycline.
Project description:Transformed human esophageal keratinocyte cell line EPC2-T (EPC2-hTERT-EGFR-cyclin D1-p53R175H) cells were stimulated with or without 2.5 ng/ml recombinant human TGF-beta1 for 10 days. The above cells were subjected to treatment for 10 days with or without 0.5 µg/ml doxycycline (DOX) to activate tetracycline-inducible (tet-on) ICN1, an active form of Notch1.
Project description:THP1 cells were transduced with MycBioID2-HMGB1 and thereafter cultured in SILAC media for 1 week. Cells were treated with doxycycline (2 ug/ml, 48h) to induce gene expression. Thereafter, doxycycline was removed and heavy labelled cells were stimulated with LPS (100 ng/ml) for 1 hour before addition of biotin (24 hours). Light cells were used as control. Biotinylated proteins were extracted and identified with LC-MS/MS
Project description:As part of our study in understanding the role of SP140 in inflammatory pathways in macrophages, we inhibited SP140 mRNA using siRNA. Peripheral blood mononuclear cells (PBMCs) were obtained from whole blood of healthy donors (from Sanquin Institute Amsterdam or from GSK Stevenage Blood Donation Unit) by Ficoll density gradient (Invitrogen). CD14+ monocytes were positively selected from PBMCs using CD14 Microbeads according to the manufacturer’s instructions (Miltenyi Biotec). CD14+ cells were differentiated with 20 ng/mL of macrophage colony-stimulating factor (M-CSF) (R&D systems) for 3 days followed by 3 days of polarization into classically activated (inflammatory) M1 macrophages (100 ng/mL IFN-γ; R&D systems). M1 macrophages were transfected with siGENOME human smartpool SP140 siRNA or non-targeting scrambled siRNA for 48h with DharmaFECT™ transfection reagents according to manufacturer’s protocol (Dharmacon). The cells were left unstimulated or stimulated with 100 ng/mL LPS (E. coli 0111:B4; Sigma) for 4h (for qPCR) or 24h (for Elisa). The cells were lysed (ISOLATE II RNA Lysis Buffer RLY-Bioline) for RNA extraction.150 ng total RNA was labelled using the cRNA labelling kit for Illumina BeadArrays (Ambion) and hybridized with Ref8v3 BeadArrays (Illumina). Arrays were scanned on a BeadArray 500GX scanner and data were normalized using quantile normalization with background subtraction (GenomeStudio software; Illumina). This submission only contains processed data
Project description:Human bone marrow-derived mesenchymal stem cells (Human BM-MSCs): Control (recombinant human LIGHT, rhLIGHT 0 ng/ml) vs rhLIGHT 200 ng/ml