1: Haematologica. 2004 Sep;89(9):1046-53. Genes transcriptionally modulated by interferon alpha2a correlate with the cytokine activity. Iolascon A, Volinia S, Borriello A, Giordani L, Moretti A, Servedio V, Maiorano N, Cucciolla V, Criniti V, Gasparini P, Indaco S, Della Ragione F. Medical Genetics University Federico II, Naples, Italy. BACKGROUND AND OBJECTIVES: Interferon alpha2a (IFNalpha2a) mediates important antiviral, antiproliferative and immunomodulatory responses and is employed in the treatment of human diseases, including chronic myelogenous leukemia. Here, we report the IFNalpha2a-dependent expression profiles of three malignant cell lines derived from liver, lymphocytes and muscle. DESIGN AND METHODS: The experiments were performed in the presence of cycloheximide, thus our results exclusively reflect direct transcriptional modulation. The short exposure time i.e. 5 hours evidences only the early events, excluding the effects of complex phenotypic changes on the expression. RESULTS: Our findings indicate that IFNalpha2a rapidly up-regulates the expression of STAT1, STAT2 and ISGF3G genes. This activity should result in the amplification of the cellular response to the cytokine. Moreover, IFNalpha2a directly modulates the expression of: (i) important transcriptional factors, e.g. IRF1 and IRF7 which control pivotal cellular events, and (ii) enzymes involved in the IFNalpha2a-dependent antiviral and apoptotic response. Interestingly, we showed that the cytokine induces transcriptional expression of Sjogren's syndrome antigen A1, a protein involved in several autoimmune diseases. INTERPRETATION AND CONCLUSIONS: The observed changes induced by IFNalpha2a could be related to the development of autoimmune syndromes observed during IFNalpha2a treatment. A number of genes transcriptionally regulated by the cytokine have been identified for the first time; these might represent additional effectors of IFNalpha2a activity. PMID: 15377465 [PubMed - in process] --------------------------------------------------------------- 2: Liver Int. 2004 Apr;24(2):149-60. Study of the effects of interferon a on several human hepatoma cell lines: analysis of the signalling pathway of the cytokine and of its effects on apoptosis and cell proliferation. Legrand A, Vadrot N, Lardeux B, Bringuier AF, Guillot R, Feldmann G. Laboratoire de Biologie Cellulaire, Unite 481 INSERM, Faculte de Medecine Xavier Bichat, Universite Paris 7, France. BACKGROUND: Interferon alpha (IFNalpha), currently used for the treatment of chronic viral hepatitis, is also known to prevent the development of hepatocellular carcinoma (HCC), the mechanism of this action being still debatable. AIMS: To study thoroughly in human hepatoma cell lines (HHL)--Hep3B, HepG2, HuH7, SKHep1, and Chang-Liver--submitted to rhIFNalpha, the signalling pathway of IFNalpha, the binding activity of the cytokine on specific gamma-activated sequence (GAS) and interferon-stimulated regulatory element (ISRE) nuclear sequences, and its effects on apoptosis and cell proliferation. METHODS: The behaviour of signal transducer and activator of transcription (STAT)1, STAT2, p48(IRF9) and the binding of nuclear proteins were investigated by immunoblot and electro-mobility shift assay. Expression of some IFNalpha-dependent proteins--p21/(WAF1), inducible nitric oxide synthase, IRF1 and 2--were studied by immunoblot. Apoptosis and the cell cycle were studied by morphological and biochemical methods. RESULTS: Transduction of INFalpha was unaltered, although there were some variations in the different HHL. Nuclear protein binding to GAS or ISRE showed that ISRE was mainly involved. Apoptosis did not occur. The cell cycle was slightly modified in HuH7. Three GAS- and/or ISRE-dependent proteins increased, suggesting that IFNalpha may have some biological effects on HHL. CONCLUSIONS: The IFNalpha signalling pathway is functional in several HHL, but the cytokine has no apoptotic effect and a moderate anti-proliferative effect. This suggests that the preventive role of IFNalpha on HCC cannot be explained by an apoptotic and/or an anti-proliferative effect, but possibly by its action on several specific nuclear sequences that protect liver cells from transformation. Copyright Blackwell Munksgaard 2004 PMID: 15078480 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 3: Leukemia. 2002 Jun;16(6):1135-42. Direct signal transduction via functional interferon-alphabeta receptors in CD34+ hematopoietic stem cells. Giron-Michel J, Weill D, Bailly G, Legras S, Nardeux PC, Azzarone B, Tovey MG, Eid P. Laboratoire d'Oncologie Virale, UPR 9045, CNRS, Villejuif, France. Affinity purified, freshly isolated CD34+ progenitors were shown to express low levels of type I interferon (IFN) receptors (740 +/- 60 binding sites/cell, K(d) 0.7 +/- 0.04 nM) determined by Scatchard's analysis using a radiolabelled, neutralizing, monoclonal antibody directed against the IFNAR1 chain of the human type I IFN receptor. Treatment of freshly isolated (day 0), highly purified (>95% pure) CD34+ cells with recombinant IFN-alpha resulted in rapid tyrosine phosphorylation and activation of STAT1, Tyk2 and JAK1 as shown by Western immunoblotting. Similarly, IFN treatment was shown by confocal microscopy to result in rapid nuclear localization of the transcription factors IRF1 and STAT2, demonstrating the presence of functional IFN receptors on freshly isolated (day 0) CD34+ cells. The number of specific type I IFN receptor binding sites expressed on hematopoietic progenitor cells increased to some 1440 +/- 40 per cell after 11 days of cultivation of CD34+ cells in vitrosuggesting that receptor expression increases with cell differentiation. IFN-mediated signal transduction and the inhibitory effect of IFN-alpha on 7 or 14 days CFU-GM and BFU-E colony formation was abrogated in the presence of the anti-IFNAR1 mAb, indicating that IFN-alpha acts directly on the proliferation of human hematopoietic progenitor cells via receptor activated signal transduction without excluding the induction of other cytokines or growth factors by residual accessory cells. PMID: 12040445 [PubMed - indexed for MEDLINE] ---------------------------------------------------------------