Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.1.21 (thymidine kinase)
 7,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Peripherin is a neuron-specific intermediate filament protein whose expression is activated in vitro by the neuropoietic cytokines leukemia inhibitory factor (LIF) and interleukin-6. We have studied the mechanisms of transcriptional activation of the peripherin gene by LIF. In particular, we have identified a 70-bp element [peripherin cytokine-responsive element (Pe-CyRE)] within the 5'-flanking sequences of the mouse peripherin gene (between -930 and -860) that enhances transcription in two neuroblastoma cell lines, NBFL and LA-N-2, in response to LIF treatment. We have also shown by DNA mobility shift assays that treatment of cells by LIF induces the binding of protein complexes composed of at least two members of the signal transducers and activators of transcription (STAT) factor family to a cis element (Pe-APRE2) within Pe-CyRE. Furthermore, the entire Pe-CyRE, as well as Pe-APRE2, conferred responsiveness onto a heterologous thymidine kinase promoter. However, the response amplitude of the heterologous promoter to LIF was lower than that observed with the 5'-flanking sequences of the peripherin promoter, suggesting that cooperative interactions with surrounding sequences of the peripherin gene are required for a full transcriptional activation.
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PMID:Transcriptional activation of the mouse peripherin gene by leukemia inhibitory factor: involvement of STAT proteins. 948 16

Gene therapy using the herpes simplex virus thymidine kinase gene (HSV-TK) is a promising new approach for the treatment of gliomas, a tumor type with a poor prognosis. To limit the toxic effects of this procedure, it is desirable to restrict expression of the HSV-TK gene to the target cells. This can be accomplished by use of the promoter of the glial fibrillary acidic protein gene, an intermediate filament protein expressed primarily in astrocytes. A plasmid containing the HSV-TK gene, driven by the human glial fibrillary acidic protein promoter gfa2, was lipofected into glioma cell lines and into an ovarian cancer cell line. Treatment with ganciclovir showed efficient killing of glioma cells, with no effect on the ovarian cells. Thus, the gfa2 promoter is a promising candidate for directing expression of toxic genes to gliomas.
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PMID:Selective killing of glioma cell lines using an astrocyte-specific expression of the herpes simplex virus-thymidine kinase gene. 978 4

Peripherin is an intermediate filament protein expressed in restricted populations of neurons. Our previous study of the chromatin structure of the mouse peripherin gene in cells that do or do not express peripherin suggested that the region located between -1,500 and +800 bp of the gene could be involved in its cell specificity. In the present work, we performed an in vitro functional analysis of the 5' flanking region of the mouse peripherin gene and observed that this region up to 9 kb contained both enhancer and inhibiting activities; however, it was insufficient to achieve a complete extinction of reporter gene expression in peripherin-negative cells. Furthermore, analysis of the first three introns with the 5' flanking sequences of the gene showed that intron I greatly increased specificity of the gene expression. Intron I also conferred the same properties to thymidine kinase heterologous promoter. DNase I footprinting experiments performed with intron I revealed at least two protected regions (Inl A and Inl B). Inl A encompasses an AP-2-like binding site that interacted with both neuroblast and fibroblast nuclear factors, as well as with the recombinant AP-2alpha protein. However, gel shift experiments suggested that the interacting nuclear factors are distinct from AP-2alpha itself and probably belong to the AP-2 family. Inl B perfectly matched the consensus binding site for Sp1 and specifically interacted with nuclear protein factors that showed the same binding properties as the Sp1 family members. Fine deletion analysis of intron I indicated that the Inl A element alone is responsible for its enhancing properties, whereas a region located between +789 and +832 gives to intron I its silencer activity.
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PMID:Involvement of intronic sequences in cell-specific expression of the peripherin gene. 1053 38

Gene therapy using the herpes simplex virus thymidine kinase (HSV-TK) gene in combination with the drug ganciclovir (GCV) is a promising approach for the treatment of cancer-inducing gliomas, a tumor with a poor prognosis. In an attempt to limit the toxic effects on normal tissues, we constructed a recombinant adenoviral vector, Adgfa2TK, in which the HSV-TK gene is driven by the promoter for the gene encoding glial fibrillary acidic protein, an intermediate filament protein expressed primarily in astrocytes. Infection by Adgfa2TK of a glial cell line (C6) and a non-glial cell line (MDA-MB-231) revealed markedly increased expression of HSV-TK in glial cells as determined by Western blot. In comparison, high HSV-TK protein levels were produced in both cell lines after infection with a control virus, AdCMVTK, in which the constitutive cytomegalovirus viral promoter was used to direct HSV-TK expression. Infection of two glial cell lines (C6, U251) and two non-glial cell lines (HepG2, MDA-MB-231) with Adgfa2TK followed by GCV treatment revealed high toxicity in glial cell lines (50% growth inhibitory concentration: <2 microg/mL of GCV) with little or no toxicity (50% growth inhibitory concentration: >75 microg/mL) in the non-glial cell lines. In vivo, injection of Adgfa2TK into C6 tumors grown in nude mice followed by intraperitoneal GCV treatment significantly repressed tumor growth compared with the controls. Adgfa2TK may be useful for directing expression of the HSV-TK gene to gliomas.
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PMID:Inhibition of glioma cells in vitro and in vivo using a recombinant adenoviral vector containing an astrocyte-specific promoter. 1097 72