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

In this study, a multiplex polymerase chain reaction (PCR) procedure was developed for differentiation of strains and field isolates of equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4). Specific oli-gonucleotide primers were combined to amplify the thymidine kinase (TK) gene region of EHV-1 and EHV-4, which would yield fragments of different lengths for each virus in the same amplification reaction. The specificity of the largest PCR amplicon for EHV-4 was confirmed by restriction digestion with HindIII. The multiplex PCR proved to be a fast and sensitive method for typing EHV-1 and EHV-4 isolates and for detection and differentiation of both viruses in field samples in which infectious virus is no longer available. The sensitivity was improved by combining cycling optimization and visualization of PCR products in ethidium bromide and silver-stained acrylamide gels.
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PMID:Development of a differential multiplex PCR assay for equine herpesvirus 1 and 4 as a diagnostic tool. 1090 Aug 26

To investigate a novel suicide gene for nasopharyngeal carcinoma (NPC) therapy, the yCDglyTK gene was constructed by fusing yeast cytosine deaminase (CD) and herpes simplex type 1 thymidine kinase. The expression of the yCDglyTK gene was detected by RT-PCR and Western blotting, and its bioactivity was demonstrated by an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. An animal study was carried out in which BALB/C nude mice bearing yCDglyTK gene-modified tumors were treated with prodrugs and radiation. Our results revealed that the yCDglyTK gene could be expressed in CNE-2 cells in vitro. In MTT analysis, at the transfection rate of 10%, 66% cells were killed. The synergistic effect of CD and TK showed 91% of yCDglyTK-transfected cells were killed with the treatment of 5-fluorocytosine (5-FC) alone, 60% killed with ganciclovir (GCV) alone, and 75% killed with 5-FC and GCV together. In vivo, the tumor volume in all of the four prodrugs and/or radiation-treated groups were significantly different from that in the PBS-controlled group (P<.01); also yCDglyTK+prodrug+radiation group was different from the other three groups (P<.05). Our findings suggested there was a synergistic antitumor effect when combining suicide gene therapy and radiation, and yCDglyTK has potent antitumor efficacy and may be a candidate suicide gene for cancer therapy.
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PMID:A novel fusion suicide gene yeast CDglyTK plays a role in radio-gene therapy of nasopharyngeal carcinoma. 1549 80

The recombinant vector (pLLTK), containing murine serum albumin (ALB) gene promoter/enhancer directing the herpes simplex virus thymidine kinase (HSV-tk) gene expression was constructed to study its effect on hepatic cell-specific damage. Firstly,in order to compare the hepatic cell-specific transcriptional activity, three vectors were constructed in which green fluorescent protein (GFP) gene was used as a reporter marker. Vector pLE was driven by murine serum ALB gene promoter,whereas pLLE contained not only murine ALB promoter but also an enhancer located at upstream of the promoter was included. In the meanwhile, the vector pLEL had a murine ALB promoter and enhancer placed at the downstream from GFP. After transfected into Hep-G2 (a human hepatic cell line) and HC-11 (a murine breast epithelial cell line), GFP expression was examined by using fluorescence microscope as well as flow cytometer. Secondly, the vector pLLTK was used to observe the killing effect on Hep-G2 cells. The results demonstrated that ALB promoter/enhancer was able to direct hepatic cell-specific GFP expression. Furthermore, HSV-tk expression in Hep-G2 cells was ganciclovir (GCV)sensitive. After seven days of culture with GCV, pLLTK-transfected Hep-G2 cells showed an obvious cell death (53%) when detected by 3-4,5 dimethylthiozol-2-yl-2, 5-diphenyl tetrazolium bromide colorimetry (MTT) assay. Compared to the untreated group, there were no obvious changes in cellular growth inhibition rate in the Hep-G2 cells transfected with a blank control vector pcDNA3. 1 (only 2% of cells appeared cell death). All these results indicated that the above constructs were hepatocyte-specific. It therefore paves a way for further creating a liver-specific damage animal model by transgenic approach using HSV-tk gene expression driven by the ALB promoter/enhancer.
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PMID:[The effect of HSV-tk/GCV on hepatic specific damage driven by murine ALB promoter/enhancer]. 1555 38

A cell survival assay of the four arabinosyl uridine analogs with functionalities of 5-fluoro, 5-fluorovinyl, 5-iodo, and 5-iodovinyl as potential positron-emitter tagged probe for monitoring cancer gene therapy were performed. Cytotoxicities of 5-fluoro-, 5-iodo-, 5-fluorovinyl, and 5-iodovinyl arabinosyl uridines against SR-39 thymidine kinase transfected murine prostate cancer cells have been evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. None of them showed significant bioactivity. A syn conformation derived from intra-hydrogen bonding was suggested for the unfavorable interaction and diminished bioactivity.
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PMID:Comparison of bioactivities of 5-Fluoro, 5-Iodo, 5-Iodovinyl, and 5-fluorovinyl arabinosyl uridines against SR-39 TK-transfected murine prostate cancer cells. 1817 88

Coxsackie adenovirus receptor (CAR) expression is the main mechanism of adenovirus entry into target cells. It is unclear whether CAR expression itself is influenced by transduction with the adenovirus-Rous sarcoma virus-thymidine kinase (ADV-RSV-TK) gene therapy construct or by the subsequent intracellular accumulation of the TK gene product. Antibody generation and characterization, immunocytochemistry, Western blotting and 3-(4,5-dimethylthiazol)-2,5-diphenyl tetrazolium bromide (MTT) assay were performed to investigate the relationship of gene transfer and CAR expression as well as differences in therapeutic susceptibility of MDAH-2774 and OVCAR-3 cell lines to ADV-RSV-TK gene therapy. CAR expression was observed on the membranes but intracellular translocation of CAR also took place dependent on cellular growth patterns. TK gene expression was dependent on multiplicity of infection (MOI) and thus on vector dose in a linear fashion. Neither TK expression nor ADV transduction influenced CAR expression, or ADV-RSV-TK transduction. Differential susceptibility of different cell lines to TK-induced cell killing by acyclovir metabolites was observed. CAR expression appears not to be influenced by adenoviral transduction or by the accumulation of the TK gene product. Differences in therapeutic sensitivity are most likely mediated by intracellular mechanisms and not by modulation of CAR expression.
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PMID:Adenovirus-mediated thymidine kinase gene therapy and coxsackie adenovirus receptor expression in ovarian cancer cells. 1928 72

Drinking water must be disinfected prior to its distribution for human consumption. This water treatment process generates disinfection by-products (DBPs), formed by the interaction of the disinfectant with organic matter, anthropogenic contaminants and inorganic (bromide/iodide) matter naturally present in source water. Due to the potential genotoxic/carcinogenic risk of these DBPs, we have investigated the mutagenic potential of six of such compounds on the thymidine kinase (Tk) gene in the well-validated mouse lymphoma assay (MLA). The MLA quantifies a wide range of genetic alterations affecting the expression of this gene in L5178Y/Tk(+/-)-3.7.2C cells. In this study we selected six emerging DBPs, corresponding to three different chemical classes: halonitromethanes (bromonitromethane and trichloronitromethane), halogenated acetaldehydes (tribromoacetaldehyde and chloral hydrate) and hydroxyfuranones (mucobromic and mucochloric acids), each class including one chlorinated and one brominated form. The results showed that after 4h of treatment, only mucobromic acid increased the frequency of mutant colonies, with a higher proportion of small colonies, which would indicate a clastogenic potential. This is the first study reporting mutagenicity data in mammalian cells for the six selected DBPs.
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PMID:Mutagenic analysis of six disinfection by-products in the Tk gene of mouse lymphoma cells. 2156 8

The aim of the present study was to investigate the selective killing effect on hepatocellular carcinoma (HCC) cells of an adenovirus (Ad)-mediated cytosine deaminase (CD) in combination with thymidine kinase (TK) suicide gene system, driven by the vascular endothelial growth factor promoter (VEGFp), in vitro and in vivo. A double suicide gene system with VEGFp, named Ad-VEGFp-CDglyTK, was constructed and transfected into human HCC cells (BEL-7402 or HepG2; the latter cell type is deficient in VEGF) and human umbilical vein vascular endothelial cells (HUVEC). Green fluorescent protein expression was detected by fluoroscopy to verify transfection efficiency, and CDglyTK gene expression was detected by reverse transcription-polymerase chain reaction (PCR). The selective killing effect of Ad-VEGFp-CDglyTK was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry (FCM) in vitro and by xenograft studies in vivo. PCR revealed that the transgenic CDglyTK gene was expressed in BEL-7402 cells and HUVEC, but not in HepG2 cells. The cell survival rate significantly decreased in line with increasing concentrations of the prodrugs, ganciclovir (GCV) alone, 5-fluorocytosine (5-FC) alone or a combination of the two, in HUVEC and BEL-7402 cells with the transfected CDglyTK gene, but not in untransfected HUVEC or BEL-7402 cells, or in transfected or untransfected HepG2 cells. This result was additionally confirmed by FCM. GCV and 5-FC inhibited the HUVEC and BEL-7402 cells containing the transfected CDglyTK gene and also inhibited adjacent unmodified cells via the 'bystander effect'. No similar results were observed in HepG2 cells. Compared with the control group, tumors with the transfected CDglyTK gene were smaller and the microvessel density of the tumor tissue was significantly decreased. It was concluded that a combination TK/GCV and CD/5-FC suicide gene system driven by VEGFp may provide a promising treatment strategy for HCC.
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PMID:A double suicide gene system driven by vascular endothelial growth factor promoter selectively kills human hepatocellular carcinoma cells. 2712 81

Cluster of differentiation (CD)133 is an important cell surface marker of glioma stem cells (GSCs). The transcription of the CD133 gene is controlled by five alternative promoters (P1, P2, P3, P4 and P5), which are expressed in a tissue-specific manner. In the present study, gene recombination technology was used to construct two types of gene expression vectors that contained the P1 promoter of the CD133 gene, which regulated either the neomycin-resistance gene or the herpes simplex virus thymidine kinase (HSV-TK) gene. Following the stable transfection of U251 glioblastoma cells with these two gene vectors, the cells expressing the P1 promoter that regulated the neomycin-resistance gene were named CD133 (+) cells, while the cells expressing the P1 promoter regulating the HSV-TK gene were called CD133 (-) cells. The expression of CD133 was detected by flow cytometry and reverse transcription-quantitative polymerase chain reaction. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to assess cell proliferation ability, while the cell cycle was analyzed by flow cytometry, and a clone formation test was performed to evaluate the invasive capability of the cells. The results demonstrated that, due to CD133 expression, the cell proliferation ability and the invasive capability of CD133 (+) cells were significantly higher than those of CD133 (-) cells. In conclusion, the present study successfully established a novel method of screening GSCs in U251 cells based on the P1 promoter of the CD133 gene.
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PMID:Screening glioma stem cells in U251 cells based on the P1 promoter of the CD133 gene. 2769 13


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