Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Retroviral vectors have been widely studied as vehicles for hepatocyte gene therapy, but they are limited by an inability to infect nondividing cells and the need for prolonged cell culture. Two replication deficient herpes simplex viral vectors (HSV) were constructed with the marker genes lac-Z/beta-galactosidase (HSVlac) or human-growth hormone (HSVhGH) to determine the efficiency of HSV gene transfer into adult human hepatocytes. Hepatocytes were isolated by collagenase perfusions and density centrifugation from liver wedge biopsy specimens obtained from six patients. After exposure to HSV (0, 50,000 and 500,000 viral particles/ 10(6) hepatocytes) for 20 minutes, 1 hour, or 2 hours, the hepatocytes were washed and placed in culture. Hepatocytes transduced with HSVlac were fixed at 24 hours and histochemically stained with X-gal, and media from HSVhgh-transduced cells were assayed at 48 hours by radioimmunoassay for hGH. After a 20-minute exposure at a multiplicity of infection of 0.5 (1 viral particle per 2 hepatocytes), greater than 35% of the hepatocytes expressed the lac-Z gene ( > 70% efficiency). hGH was also detected in the media from HSVhGH-transduced cells, showing that proteins coded for by foreign cells are not only expressed by transduced cells but are also secreted. Isolated liver perfusions using HSVlac were also performed in Fischer rats. A 20-minute isolated perfusion using 5 x 10(6) viral particles resulted in expression of the beta-galactosidase gene in the rodent livers 72 hours later without histological signs of tissue injury.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Rapid and efficient gene transfer in Human hepatocytes by herpes viral vectors. 765 75

The Jun protein binds DNA and regulates transcription as a component of the AP-1 transcription factor complex. In its oncogenic form, Jun can transform cells in culture and cause tumors in animals. Both trans-activation and transformation require several functional domains of Jun, including an amino-terminal trans-activation domain. In this study, properties of Jun required for trans-activation and transformation were explored by replacing the trans-activation domains of c-Jun and its oncogenic counterpart, v-Jun, with the constitutively active trans-activation domain from the herpes simplex virus VP16 protein. The VP16-v-Jun chimera retained similar oncogenic properties to its parent, v-Jun. The VP16-c-Jun chimera, however, was considerably more oncogenic than c-Jun. Substitutions of a phenylalanine in the VP16 domain of the VP16-c-Jun chimera diminished or abolished transformation. Each of the chimeras bound to the AP-1 consensus recognition sequence from the collagenase promoter or from the human T-cell leukemia virus type I long terminal repeat in vitro. None of the VP16-Jun chimeras efficiently stimulated transcription from the collagenase promoter or an artificial promoter containing the human T-cell leukemia virus type I element in vivo. These results demonstrate that the Jun trans-activation domain can be replaced by a heterologous trans-activation domain with retention of oncogenic activity. However, this oncogenic activity is not reflected in the trans-activating properties of the chimeras.
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PMID:Chimeras of herpes simplex viral VP16 and jun are oncogenic. 824 Oct 24

Effective virus-mediated gene therapy for cancer will be facilitated by procedures that enhance the low level of gene transfer mediated by replication-deficient, recombinant viral vectors. We found recently that protease pretreatment of solid tumors is a useful strategy for enhancing virus-mediated gene transduction in vivo. In this study, we examined the potential of protease pretreatment to improve the efficacy of a gene therapy strategy for prodrug activation that depends on infection with a recombinant adenovirus encoding herpes simplex virus thymidine kinase (Ad-HSV-tk). Trypsin or a dissolved mixture of collagenase/dispase was inoculated into xenografts derived from the human glioblastoma multiforme-derived cell lines, U87 or U251. Ad-HSV-tk was administered 24 h after protease pretreatment, and animals were then treated for 10 days with ganciclovir (GCV). We found that protease pretreatment increased the efficacy of adenovirus mediated HSV-tk/GCV gene therapy in these experimental tumor models. Mice receiving Ad-HSV-tk/GCV after protease pretreatment demonstrated a significantly greater regression of tumors compared with those treated with Ad-HSV-tk/GCV alone. No adverse effects of protease pretreatment were observed. No signs of metastasis were seen either by histological inspection of lymph nodes or by a PCR-based analysis of selected mouse tissues to detect human tumor cells. Our findings indicate that protease pretreatment may be a useful strategy to enhance the efficacy of virus-mediated cancer gene therapy.
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PMID:Protease pretreatment increases the efficacy of adenovirus-mediated gene therapy for the treatment of an experimental glioblastoma model. 1128 Jul 27

To determine the distribution and activities of metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) during the course of experimental herpes simplex virus (HSV) type-1 keratitis, BALB/c mice were corneally infected with 10(5) plaque-forming units (PFU) of HSV-1 (KOS strain) and then observed for the clinical signs of keratitis. Corneas were harvested at days 0, 2, 7 and 14 post-infection (p.i.). MMP-2, MMP-9, MMP-8, TIMP-1 and TIMP-2 were detected by immunohistochemistry and the Western blot technique. The enzymatic activities were analyzed by zymography. Epithelial HSV keratitis was present at day 2 after corneal infection and healed by day 5 p.i. While the expression and activity of MMP-2, MMP-8 and MMP-9 increased in the corneas at day 2 p.i., it was reduced at day 7 p.i. TIMP-1 and -2 were expressed in the corneas before and seven days after infection. Necrotizing stromal keratitis with corneal ulceration and dense polymorphonuclear leukocyte (PMN) infiltration was present at day 14 p.i. This correlated with increased expression of MMP-2, MMP-8 and MMP-9 in the corneas. MMP-8, MMP-9 and MMP-2 staining was particularly intense in the proximity of the ulcers and in areas of PMN infiltration. At day 14 p.i., MMP-2, -8 and -9 activities were upregulated, and TIMP-2 was expressed. These data suggest that MMPs produced by resident corneal cells and PMNs may possibly play a role in early epithelial keratitis and in the ulcerative process in the late phase after corneal HSV-1 infection. The ratio of MMPs to TIMPs may be important for the course of necrotizing HSV keratitis. TIMPs might participate in the repair process.
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PMID:Matrix metalloproteinases (MMP-2 and 9) and tissue inhibitors of matrix metalloproteinases (TIMP-1 and 2) during the course of experimental necrotizing herpetic keratitis. 1287 54

Oncolytic viral therapy provides a promising approach to treat certain human malignancies. These vectors improve on replication-deficient vectors by increasing the viral load within tumors through preferential viral replication within tumor cells. However, the inability to efficiently propagate throughout the entire tumor and infect cells distant from the injection site has limited the capacity of oncolytic viruses to achieve consistent therapeutic responses. Here we show that the spread of the oncolytic herpes simplex virus (HSV) vector MGH2 within the human melanoma Mu89 is limited by the fibrillar collagen in the extracellular matrix. This limitation seems to be size specific as nanoparticles of equivalent size to the virus distribute within tumors to the same extent whereas smaller particles distribute more widely. Due to limited viral penetration, tumor cells in inaccessible regions continue to grow, remaining out of the range of viral infection, and tumor eradication cannot be achieved. Matrix modification with bacterial collagenase coinjection results in a significant improvement in the initial range of viral distribution within the tumor. This results in an extended range of infected tumor cells and improved virus propagation, ultimately leading to enhanced therapeutic outcome. Thus, fibrillar collagen can be a formidable barrier to viral distribution and matrix-modifying treatments can significantly enhance the therapeutic response.
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PMID:Degradation of fibrillar collagen in a human melanoma xenograft improves the efficacy of an oncolytic herpes simplex virus vector. 1651 May 65

Oncolytic viral vectors show enormous potential for the treatment of many solid tumors. However, these vectors often suffer from insufficient delivery within tumors, which limits their efficacy in both preclinical and clinical settings. We have previously shown that tumor collagen can significantly hinder diffusion, and that its degradation can enhance the distribution and efficacy of an oncolytic herpes simplex virus (HSV) vector. Here, we identify two members of the matrix metalloproteinase (MMP) family of enzymes, MMP-1 and MMP-8, which can modulate the tumor matrix and enhance HSV delivery and efficacy. We show that overexpression of MMP-1 and MMP-8 in the human soft tissue sarcoma HSTS26T leads to a significant depletion of tumor-sulfated glycosaminoglycans. This increases the hydraulic conductivity of these tumors and enhances the flow of virus during injection. In control tumors, injected virus accumulates primarily in the periphery of the tumor. In contrast, we observed a more widespread distribution of virus around the injection site in MMP-1- and MMP-8-expressing tumors. Due to this enhanced vector delivery, MMP-expressing tumors respond significantly better to oncolytic HSV treatment than control tumors. Thus, these findings introduce a new approach to improve the delivery and efficacy of oncolytic viral vectors: modulation of tumor glycosaminoglycans to enhance convection.
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PMID:Matrix metalloproteinases-1 and -8 improve the distribution and efficacy of an oncolytic virus. 1800 7


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