Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Novel approaches are needed to improve the antitumor potency and to increase the cancer specificity of oncolytic adenoviruses (Ad). We hypothesized that the combination of interferon-alpha (IFN-alpha) expression with a specific mutation in the e1a gene of Ad could target vector replication to genetic defects in the IFN-alpha pathway resulting in both improved antitumor efficacy and reduced toxicity. The conditionally replicative Ad vector KD3-IFN carries the dl1101/1107 mutation in the e1a gene that eliminates binding of E1A proteins to p300/CBP and pRb. KD3-IFN expresses human IFN-alpha in concurrence with vector replication and overexpresses the adenovirus death protein (ADP; E3-11.6K). The antitumor activity of KD3-IFN was significantly higher than that of a control vector in established human hepatocellular carcinoma tumors in immunodeficient mice and in hamster kidney cancer tumors in immunocompetent Syrian hamsters. The dl1101/1107 mutation rendered Ad replication sensitive to the antiviral effect of IFN-alpha in normal as opposed to cancer cells. These results translated to reduced vector toxicity upon systemic administration to C57BL/6 mice. The combination of Ad oncolysis, ADP overexpression, and IFN-alpha-mediated immunotherapy represents a three-pronged approach for increasing the anticancer efficacy of replicative Ads. Exploiting the dl1101/1107 mutation provides a mechanism for additional selectivity of IFN-alpha-expressing replication-competent Ads.
Mol Ther 2007 Mar
PMID:Targeting interferon-alpha increases antitumor efficacy and reduces hepatotoxicity of E1A-mutated spread-enhanced oncolytic adenovirus. 1719 Oct 72

Hormone refractory metastatic prostate cancer is a deadly disease that currently lacks curative treatments. Conditionally replicating adenoviruses (CRAds) are promising new agents against cancer due to their innate capability to cause oncolysis of tumor cells. Their antitumor effect is determined in part by their capacity for infecting cancer cells. However, the respective primary receptor, the coxsackie-adenovirus receptor (CAR), is variably expressed in many cancer types. We created Ad5/3Delta24hCG, a novel CRAd retargeted to the adenovirus serotype 3 receptor, which has been reported to be highly expressed in tumors. Furthermore, we added a transgene for the beta-chain of human chorionic gonadotropin (hCGbeta), whose expression was tightly coupled to virus replication. Ad5/3Delta24hCG was found effective in killing prostate cancer cells, and oncolysis was seen in concordance with hCGbeta production. In a s.c. in vivo model of hormone refractory prostate cancer, Ad5/3Delta24hCG treatment resulted in statistically significant tumor growth inhibition. Moreover, i.v. injection of Ad5/3Delta24hCG prolonged the survival of mice with hormone refractory prostate cancer metastatic to the lung. Detection of hCGbeta in serum samples confirmed viral replication in vivo. Infection of human clinical samples of cancerous and normal prostatic tissue resulted in effective hCGbeta production in cancer tissue, whereas it remained low in nonmalignant tissue, suggesting cancer-specific replication. These results suggest that Ad5/3Delta24hCG is a potent virus for the treatment of hormone refractory prostate cancer in vitro and in vivo. These preclinical data set the stage for translation into clinical studies.
Mol Cancer Ther 2007 Feb
PMID:Treatment of prostate cancer with Ad5/3Delta24hCG allows non-invasive detection of the magnitude and persistence of virus replication in vivo. 1730 70

Reovirus, a potential cancer therapy, replicates more efficiently in Ras-transformed cells than in non-transformed cells. It was presumed that increased translation was the mechanistic basis of reovirus oncolysis. Analyses of each step of the reovirus life cycle now show that cellular processes deregulated by Ras transformation promote not one but three viral replication steps. First, in Ras-transformed cells, proteolytic disassembly (uncoating) of the incoming virions, required for onset of infection, occurs more efficiently. Consequently, threefold more Ras-transformed cells become productively infected with reovirus than non-transformed cells, which accounts for the observed increase of reovirus proteins in Ras-transformed cells. Second, Ras transformation increases the infectious-to-noninfectious virus particle ratio, as virions purified from Ras-transformed cells are fourfold more infectious than those purified from non-transformed cells. Progeny assembled in non- and Ras-transformed cells appear similar by electron microscopy and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis, suggesting that Ras transformation introduces a subtle change necessary for virus infectivity. Finally, reovirus release, mediated by caspase-induced apoptosis, is ninefold more efficient in Ras-transformed cells. The combined effects of enhanced virus uncoating, infectivity, and release result in >100-fold differences in virus titers within one round of replication. Our analysis reveals previously unrecognized mechanisms by which Ras transformation mediates selective viral oncolysis.
Mol Ther 2007 Aug
PMID:Ras transformation mediates reovirus oncolysis by enhancing virus uncoating, particle infectivity, and apoptosis-dependent release. 1764 36

Vesicular stomatitis virus (VSV) can replicate in malignant cells more efficiently than in normal cells. Although the selective replication appears to be caused by defects in the interferon (IFN) system in malignant cells, the mechanisms which render these cells less responsive to IFN remain poorly understood. Here we present evidence that an activated RAS/Raf1/MEK/ERK pathway plays a critical role in the defects. NIH 3T3 or human primary cells stably expressing active RAS or Raf1 were rapidly killed by VSV. Although IFNalpha treatment no longer protected the RAS- or Raf1-overexpressing cells from VSV infection, responsiveness to IFNalpha was restored following treatment with the mitogen-activated protein kinase kinase (MEK) inhibitor U0126. Similarly, human cancer-derived cell lines became more responsive to IFNalpha in conjunction with U0126 treatment. Intriguingly, dual treatment with both IFNalpha and U0126 severely reduced the levels of viral RNAs in the infected cells. Moreover, cancer cells showed defects in inducing an IFNalpha-responsive factor, MxA, which is known to block VSV RNA synthesis, and U0126 restored the MxA expression. Our observations suggest that activation of the extracellular signal-regulated protein kinase (ERK) signaling leads to the defect in IFNalpha-mediated upregulation of MxA protein, which facilitates VSV oncolysis. In view of the fact that 30% of all cancers have constitutive activation of the RAS/Raf1/MEK/ERK pathway, VSV would be an ideal oncolytic virus for targeting such cancers.
Mol Ther 2007 Aug
PMID:The RAS/Raf1/MEK/ERK signaling pathway facilitates VSV-mediated oncolysis: implication for the defective interferon response in cancer cells. 1750 73

Mammalian ortheoreoviruses are currently being investigated as novel cancer therapeutics, but the cellular mechanisms that regulate susceptibility to reovirus oncolysis remain poorly understood. In this study, we present evidence that virion disassembly is a key determinant of reovirus oncolysis. To penetrate cell membranes and initiate infection, the outermost capsid proteins of reovirus must be proteolyzed to generate a disassembled particle called an infectious subviral particle (ISVP). In fibroblasts, this process is mediated by the endo/lysosomal proteases cathepsins B and L. We have analyzed the early events of infection in reovirus-susceptible and -resistant cells. We find that, in contrast to susceptible glioma cells and Ras-transformed NIH3T3 cells, reovirus-resistant cancer cells and untransformed NIH3T3 cells restrict virion uncoating and subsequent gene expression. Disassembly-restrictive cells support reovirus infection, as in vitro-generated ISVPs establish productive infection, and pretreatment with poly(I:C) does not prevent infection in cancer cells. We find that the level of active cathepsin B and L is increased in tumors and that disassembly-restrictive glioma cells support reovirus oncolysis when grown as a tumor in vivo. Together, these results provide a model in which proteolytic disassembly of reovirus is a critical determinant of susceptibility to reovirus oncolysis.
Mol Ther 2007 Aug
PMID:Proteolytic disassembly is a critical determinant for reovirus oncolysis. 1764 36

Tumour necrosis factor-stimulated gene-6 (TSG-6) is a glycosaminoglycan-binding protein expressed during inflammatory and inflammation-like processes. Previously NMR structures were calculated for the Link module of TSG-6 (Link_TSG6) in its free state and when bound to an octasaccharide of hyaluronan (HA(8)). Heparin was found to compete for HA binding even though it interacts at a site that is distinct from the HA-binding surface. Here we present crystallography data on the free protein, and (15)N NMR relaxation data for the uncomplexed and HA(8)-bound forms of Link_TSG6. Although the Link module is comparatively rigid overall, the free protein shows a high degree of mobility in the beta4/beta5 loop and at the Cys47-Cys68 disulfide bond, both of which are regions involved in HA binding. When bound to HA(8), this dynamic behaviour is dampened, but not eliminated, suggesting a degree of dynamic matching between the protein and sugar that may decrease the entropic penalty of complex formation. A further highly dynamic residue is Lys54, which is distant from the HA-binding site, but was previously shown to be involved in heparin binding. When HA is bound, Lys54 becomes less mobile, providing evidence for an allosteric effect linking the HA and heparin-binding sites. A mechanism is suggested involving the beta2-strand and alpha2-helix. The crystal structure of free Link_TSG6 contains five molecules in the asymmetric unit that are highly similar to the NMR structure and support the dynamic behaviour seen near the HA-binding site: they show little or no electron density for the beta4/beta5 loop and display multiple conformations for the Cys47-Cys68 disulfide bond. The crystal structures were used in docking calculations with heparin. An extended interface between a Link_TSG6 dimer and heparin 11-mer was identified that is in excellent agreement with previous mutagenesis and calorimetric data, providing the basis for further investigation of this interaction.
J Mol Biol 2007 Aug 17
PMID:Plasticity of the TSG-6 HA-binding loop and mobility in the TSG-6-HA complex revealed by NMR and X-ray crystallography. 1758 36

The patients with Crohn's disease (CD) have a 'leaky gut' manifested by an increase in intestinal epithelial tight junction (TJ) permeability. Tumour necrosis factor-alpha (TNF-alpha) is a proto-typical pro-inflammatory cytokine that plays a central role in intestinal inflammation of CD. An important pro-inflammatory action of TNF-alpha is to cause a functional opening of intestinal TJ barrier. Previous studies have shown that TNF-alpha increase in TJ permeability was regulated by an increase in myosin light chain kinase (MLCK) gene activity and protein expression. The major aim of this study was to elucidate the cellular and molecular mechanisms that mediate basal and TNF-alpha-induced increase in MLCK gene activity. By progressive 5' deletion, minimal MLCK promoter was localized between -313 to +118 on MLCK promoter. A p53 binding site located within minimal promoter region was identified as an essential determinant for basal promoter activity. A 4 bp start site and a 5 bp downstream promoter element were required for MLCK gene activity. TNF-alpha-induced increase in MLCK promoter activity was mediated by NF-kappaB activation. There were eight kappaB binding sites on MLCK promoter. The NF-kappaB1 site at +48 to +57 mediated TNF-alpha-induced increase in MLCK promoter activity. The NF-kappaB2 site at -325 to -316 had a repressive role on promoter activity. The opposite effects on promoter activity were due to differences in the NF-kappaB dimer type binding to the kappaB sites. p50/p65 dimer preferentially binds to the NF-kappaB1 site and up-regulates promoter activity; while p50/p50 dimer preferentially binds to the NF-kappaB2 site and down-regulates promoter activity. In conclusion, we have identified the minimal MLCK promoter region, essential molecular determinants and molecular mechanisms that mediate basal and TNF-alpha-induced modulation of MLCK promoter activity in Caco-2 intestinal epithelial cells. These studies provide novel insight into the cellular and molecular mechanisms that regulate basal and TNF-alpha-induced modulation of MLCK gene activity.
J Cell Mol Med 2008 Aug
PMID:Cellular and molecular mechanisms that mediate basal and tumour necrosis factor-alpha-induced regulation of myosin light chain kinase gene activity. 1836 37

Tumour necrosis factor superfamily member 11 (TNFSF11) gene, that codes for receptor activator of nuclear factor-kappaB ligand, is one of the candidate genes for the genetic susceptibility to osteoporosis. As variations in the TNFSF11 gene promoter could alter its expression, the aim of the study was to evaluate the functional influence of three polymorphisms in the promoter and to investigate their association with bone mineral density (BMD) and biochemical markers in postmenopausal women. A total of 404 postmenopausal women were genotyped for the presence of TNFSF11 gene promoter polymorphisms -290C>T, -643C>T and -693G>C. Two common haplotypes, CCG and TTC, which occur in 44.3 and 49.3% of subjects respectively, were subjected to functional analysis. Amplified fragments were cloned into pGL3-basic reporter plasmid, which was co-transfected with pRL-TK plasmid into HEK293 cells. Dual luciferase reporter assay was performed. BMD and biochemical markers were measured. Reporter gene analysis showed significantly higher luciferase activity in CCG than in TTC haplotype (P=0.018). Both showed association with lumbar spine BMD (BMD-ls; P=0.005 and 0.007 for TTC and CCG respectively), whereas in femoral neck there was no association with BMD. In postmenopausal osteoporosis, association with BMD-ls was established in -290C>T, -643C>T and -693G>C (P values: 0.001, 0.041 and 0.013 respectively). Association with femoral neck BMD was shown in -693G>C (P=0.049). No association was found with biochemical markers in any of the groups. Our results suggest that in postmenopausal osteoporosis, TNFSF11 gene promoter polymorphisms -290C>T, -643C>T and -693G>C play a functional role in the genetic regulation of BMD.
J Mol Endocrinol 2008 Jun
PMID:Tumour necrosis factor superfamily member 11 gene promoter polymorphisms modulate promoter activity and influence bone mineral density in postmenopausal women with osteoporosis. 1850 20

Conditionally replicating adenoviruses (CRAd) can replicate specifically in cancer cells and lyse them. The CRAds were widely used in the preclinical and clinical studies of cancer therapy. We hypothesize that more precisely regulated replication of CRAds may further improve the vector safety profile and enhance its antitumor efficacy. Here, a triple-regulated CRAd carrying p53 gene expression cassette, SG600-p53, was engineered. In SG600-p53, the E1a gene with a deletion of 24 nucleotides within CR2 region is controlled under the human telomerase reverse transcriptase (hTERT) promoter, the E1b gene expression is directed by the hypoxia response element (HRE), whereas the p53 gene is controlled by the cytomegalovirus promoter. The precise triple-regulation endows SG600-p53 with enhanced antitumor potential and improved safety profile. The tumor-selective replication of this virus and its antitumor efficacy were characterized in several tumor cell lines in vitro and in xenograft models of human non-small cell lung cancer in nude mice. With the selective replication and oncolysis, it was found by ELISA assay that SG600-p53 expressed p53 efficiently in cancer cells. In NCI-H1299 tumor xenograft models, SG600-p53 displayed a tumor-selective killing capacity. At a dose of 2 x 10(9) plaque-forming units, SG600-p53 could completely inhibit the tumor growth and more effective than replication-defective Ad-p53. Histopathologic examination revealed that SG600-p53 administration resulted in cancer cell apoptosis. We concluded that the triple-regulated SG600-p53, as a more potent and safer antitumor therapeutic, could provide a new strategy for cancer biotherapy.
Mol Cancer Ther 2008 Jun
PMID:A novel triple-regulated oncolytic adenovirus carrying p53 gene exerts potent antitumor efficacy on common human solid cancers. 1856 30

JX-594 is a targeted oncolytic poxvirus that is designed to eradicate cancer cells having cell-cycle defects, through replication, cell lysis, and spread within tumors; oncolysis-induced tumor vascular shutdown and immunostimulation are augmented by granulocyte monocyte-colony-stimulating factor (GM-CSF) transgene expression. We have previously shown, in animal models of hepatocellular carcinoma (HCC), that JX-594 is a promising anticancer agent. We tested JX-594 in three patients with advanced refractory hepatitis B virus (HBV)-associated HCC through intratumoral administration. JX-594 treatment was well-tolerated and resulted in antitumoral efficacy in all three patients, despite the presence of high levels of neutralizing antibodies. JX-594 replication, its release into the circulation, distant tumor targeting were demonstrated. JX-594 administration resulted in the induction of antivascular cytokines, and was associated with tumor vascular shutdown. We also showed, for the first time, that oncolytic virotherapy can suppress underlying HBV replication in HCC patients, and that tumor tissue could be the primary source of acute HBV replication and acute post-treatment HBV release. JX-594 treatment in HBV-associated HCC warrants further clinical testing; a Phase II trial is underway.
Mol Ther 2008 Sep
PMID:The targeted oncolytic poxvirus JX-594 demonstrates antitumoral, antivascular, and anti-HBV activities in patients with hepatocellular carcinoma. 1872 77


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