Project description:MicroRNAs are positive and negative regulators of eukaryotic gene expression that modulate transcript abundance by specific binding to sequence motifs located prevalently in the 3’ untranslated regions (3’-UTR) of target messenger RNAs (mRNA). Interferon-alpha-2a (IFNα) induces a large set of protein-coding genes mediating anti-proliferative and antiviral responses. Here we use a global microarray-based microRNA detection platform to identify genes that are induced by IFNα in hepatoma- or melanoma-derived human tumor cell lines. Despite the enormous differences in expression levels between these models, we were able to identify microRNAs that are upregulated by IFNα in both lines, suggesting the possibility that interferon-regulated microRNAs (IRmiRs) are involved in the transcriptional repression of mRNA relevant to cytokine responses.
Project description:A hallmark of resistance to type I interferons (IFNs) is the lack of antiproliferative responses. Foser et al. 2006 have shown that costimulation with IFN-alpa and transforming growth factor beta-1 (TGF-beta) potentiates antiproliferative activity in a sensitive (ME15) and resistant (D10) human melanoma cell line. Gene induction by small concentration of interferon-alpha-2a (100 U/ml) was analyzed in human cancer cell lines with differences in sensitivity to IFN-alpha and TGF-beta. Among other antiproliferative genes we found upregulated IFITM3 gene expression levels and inducibility of this antiproliferative protein in interferon sensitive cell lines.
Project description:STAT1 plays a cental role in the induction of interferon-stimulated genes, but interferon alpha can activate a STAT1-independent pathway that leads to gene expression. We performed microarray analysis to examine whether like interferon alpha, interferon lambda, a newly discovered interferon, can induce the expression of interferon-stimulated genes in the absence of STAT1. Control and STAT1 knockout Huh-7.5 hepatoma cells were left untreated or treated with 1000 U/ml of human interferon alpha 2a or interferon lambda 1 (PBL) for 24 h, and total RNA was extracted. Sense-strand DNA was generated from 200 ng of total RNA, fragmented, and labeled using a GeneChip WT Plus Reagent Kit (Affymetrix). Six samples were obtained and each sample was anlyzed using one GeneChip.
Project description:This protocol will evaluate the activity of 5-Fluorouracil (FUra) given as a 1 hour infusion in combination with leucovorin (LV) and interferon IFN alpha-2a in patients with advanced, measurable colorectal cancer.
Project description:The purpose of this experiment was to obtain samples for microRNA analysis in IHH cells infected with human interferon alpha. Immortalized human hepatocyte (IHH) cells were seeded at 1 x 10^6 cells per well on 6 well plates 3 days before infection. Treatments were initiated by replacing culture medium (containing 10% FBS) with fresh medium containing 500 U/ml of human interferon α (PBL Biosciences). Mock-treated cells were given normal culture medium only. Mock and treated cells were incubated at 37°C until sample collection time points. Infected samples were collected in triplet; time-matched mocks were collected in triplet in parallel with infected samples. Time points: 6, 12, and 18 h post-infection
Project description:Interferon-alpha (pegylated interferon and ribavirin) is used as standard-of-care therapeutic for chronic hepatitis C virus infection. Besides good cure in some patients other patients do not benefit from the treatment dependent on the virus type and host factors. One class of putative effector proteins is the family of Suppressors of cytokine signalling (SOCS). They act in a classical negative feedback-loop against the action of interferons and many other cytokines. It has been proven that some of them, in particular SOCS1 and SOCS3, inhibit the expression of interferon induced antiviral proteins. Their mode of action depends on the signal they are interfering with. In relation to the interferon-gamma pathway, they are thought to act on the interferon-alpha receptors by masking its recognition site for the Janus kinases (JAK), by blocking the kinase activity of the JAKs and coincidentally hindering STAT molecules from binding to the kinases. They are also thought to ubiquitinate the JAKs resulting in their proteosomal degradation. The function of SOCS proteins in suppressing the interferon-alpha pathway has not yet been characterized exhaustively. This study should unveil links to understand the resistance in interferon-alpha therapy. As results we got almost complete silencing of JAK-STAT signaling in SOCS1 over-expressing cells and tissue-dependent partially suppressed gene induction in SOCS3 over-expressing cell lines. Two human cancer cell lines (ME-15, HuH-7) were stably transfected with pcDNA3.1-SOCS plasmids in presence of geneticin and daughter cell lines were generated after singularization of cells. Next, original cell lines as well as SOCS1 and SOCS3 over-expressing cell lines were treated with 1000 U/ml interferon-alpha for 4 or 24 hours or in normal culture medium. Cells lines obtained from SOCS4 plasmid transfections were screened as additional control. Gene expression levels of cell cultured in control (0 for 4 hours, 2 for 24 hours) or interferon-alpha supplemented medium for 4 hours (1) or 24 hours (4) were analyzed. mRNA abundance was measured in triplicates using 12x8-sample commercial Illumina microarrays (HumanRef 8, version 3) and scanner system (iScan) as well as reagents recommend by Illumina (IlluminaM-BM-. TotalPrep Kit).