Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0029463 (osteosarcoma)
16,637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genetic changes found in human osteogenic sarcoma cells, including loss of the p53 and Rb tumor suppressor elements and overexpression of the cyclin G1 (CYCG1) proto-oncogene, suggest the potential of gene transfer as a treatment for metastatic disease. In this study, we examined the effects of antisense cyclin G1, in comparison with antisense cyclin D1 (CYCD1) and enforced expression of the universal cyclin-dependent kinase inhibitor p21WAF1/CIP1 on the proliferation of human MG-63 osteosarcoma cells. Retroviral vectors bearing antisense CYCG1 as well as antisense CYCD1 and WAF1/CIP1 (in sense orientation) driven by the Moloney murine leukemia virus long terminal repeat promoter inhibited the growth and/or survival of transduced MG-63 cells in 2-7 day cultures. This represents the first demonstration that cyclin G1 is essential for the survival and/or growth of human osteosarcoma cells. Cytostatic and cytopathic effects were accompanied by a significant increase in the incidence of apoptosis, as determined by immunocytochemical analysis of DNA fragmentation. Furthermore, transduction of MG-63 cells with a retroviral vector bearing the suicide gene, herpes simplex thymidine kinase (HStk), induced cell death on treatment with ganciclovir, exhibiting pronounced bystander effects. Taken together, the data affirm the feasibility of modulating inducible cell cycle control enzymes as a potential gene therapy approach in the clinical management of osteogenic sarcoma.
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PMID:Retroviral vector-mediated gene transfer of antisense cyclin G1 (CYCG1) inhibits proliferation of human osteogenic sarcoma cells. 758 20

Fifteen patients with primary classical osteosarcoma tumours are presented, all of whom have been operated on with local en bloc resection of the tumour mass in combination with adjuvant treatment with human leucocyte interferon. All patients have at present been followed up for more than fifteen years and half of them have shown no tumour recurrence. One patient committed suicide and eight died of generalized tumour disease. Two patients developed lung metastases five and eight years after primary surgery. This form of treatment, allowing limb preservation, is presented as an alternative to conventional ablative surgery providing that it is reserved for centres with specialized surgical teams.
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PMID:Local tumour resection in interferon treated osteosarcoma patients. 764 12

We constructed a series of adenoviral (Ad) vectors that express the Candida albicans cytosine deaminase (CD) suicide gene under the transcriptional control of either the human alpha-lactalbumin (ALA) or ovine beta-lactoglobulin (BLG) promoter (Ad.ALA.CD and Ad.BLG.CD, respectively). The Ad.ALA.CD and the Ad.BLG.CD vectors converted the prodrug 5-fluorocytosine (5-FC) to the toxic nucleotide analog 5-fluorouracil in a breast cancer cell-specific manner, with a conversion rate of 40% and 52% in T47D cells and 50% and 41% in MCF7 cells, respectively. No significant conversion (< or =3%) was observed in an immortalized nontumorigenic breast epithelial cell line (MCF10A) and a human osteosarcoma cell line (U2OS). Adenovirus vector-based prodrug conversion of the 5-FC in T47D and MCF7 in the presence of 1 mg/mL of 5-FC led to cytotoxicity that resulted in a nearly complete cell death (> or =90%) after 5 days, whereas MCF10A and U2OS cells remained resistant (< or =10%). Nude mice harboring T47D-derived breast tumors that were injected intratumorally (i.t.) with therapeutic adenovirus vectors at a dose of 2 x 10(8) plaque-forming units and treated systemically with 5-FC at a concentration of 500 mg/kg/day showed a marked reduction in tumor mass within 30 days when compared with animals that received vector alone. Animal survival was significantly prolonged after 72 days in mice treated with therapeutic vectors in conjunction with prodrug when compared with control animals. These preclinical data are sufficiently promising to warrant further studies of this transcriptional targeting approach to breast cancer treatment.
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PMID:Breast cancer-specific expression of the Candida albicans cytosine deaminase gene using a transcriptional targeting approach. 1088 14

Nucleoside kinases from several species are investigated as "suicide genes" for treatment of malignant tumors by combined gene/chemotherapy. We have recently cloned a multisubstrate deoxyribonucleoside kinase of Drosophila melanogaster (Dm-dNK), and we have shown that the enzyme phosphorylates cytotoxic pyrimidine and purine nucleoside analogs. The broad substrate specificity of the enzyme, as well as its very high catalytic rate, makes it a unique member of the nucleoside kinase enzyme family. In the present study, we evaluated Dm-dNK as a suicide gene by constructing a replication-deficient retroviral vector that expresses the enzyme. The human pancreatic adenocarcinoma cell line MIA PaCa-2 and a thymidine kinase-deficient osteosarcoma cell line were transduced with the recombinant virus. We showed that Dm-dNK can be expressed in human cells, that the enzyme retained its enzymatic activity, and that it is localized in the cell nuclei due to a nuclear localization signal in its C-terminal region. The cells expressing Dm-dNK exhibited increased sensitivity to several cytotoxic nucleoside analogs, such as 1-beta-d-arabinofuranosylcytosine, 1-beta-d-arabinofuranosylthymine, (E)-5-(2-bromovinyl)-2'-deoxyuridine, 2-chloro-2'-deoxyadenosine, and 2',2'-difluorodeoxycytidine. These findings suggest that Dm-dNK may be used as a suicide gene in combined gene/chemotherapy of cancer.
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PMID:Retroviral transduction of cancer cell lines with the gene encoding Drosophila melanogaster multisubstrate deoxyribonucleoside kinase. 1099 93

The broad substrate specificity of herpes simplex virus type 1 (HSV-1) thymidine kinase (TK) has provided the basis for selective antiherpetic therapy and, more recently, suicide gene therapy for the treatment of cancer. We have now constructed an HSV-1 TK mutant enzyme, in which an asparagine (N) residue is substituted for glutamine (Q) at position 125, and have evaluated the effect of this amino acid change on enzymatic activity. In marked contrast with wild-type HSV-1 TK, which displays both thymidine kinase and thymidylate kinase activities, the HSV-1 TK(Q125N) mutant was unable to phosphorylate pyrimidine nucleoside monophosphates but retained significant phosphorylation activity for thymidine and a series of antiherpetic pyrimidine and purine nucleoside analogs. The abrogation of HSV-1 TK-associated thymidylate kinase activity resulted in a 100-fold accumulation of the monophosphate form of (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) in osteosarcoma cells transfected with the HSV-1 TK(Q125N) gene compared with osteosarcoma cells expressing wild-type HSV-1 TK. BVDU monophosphate accumulation gave rise to a much greater inhibition of cellular thymidylate synthase in HSV-1 TK(Q125N) gene-transfected cells than wild-type HSV-1 TK gene-transfected osteosarcoma tumor cells without significantly changing the cytostatic potency of BVDU for the HSV-1 TK gene-transfected tumor cells. Accordingly, the presence of the Q125N mutation in HSV-1 TK gene-transfected tumor cells was found to result in a multilog decrease in the cytostatic activity of those pyrimidine nucleoside analogs that in their monophosphate form do not have marked affinity for thymidylate synthase [i.e., 1-beta-D-arabinofuranosylthymine and (E)-5-(2-bromovinyl)-1-beta-D-arabinofuranosyluracil].
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PMID:Mutation of Gln125 to Asn selectively abolishes the thymidylate kinase activity of herpes simplex virus type 1 thymidine kinase. 1116 Aug 65

In human cells, telomerase activity is regulated by transcriptional control of the telomerase reverse transcriptase gene (hTERT) whose product is the catalytic subunit of the enzyme. The hTERT promoter is active in virtually all types of tumors and immortal cells, but is silent in most adult somatic tissues. In this study, we placed the herpes simplex virus thymidine kinase gene under the control of the hTERT promoter with the aim of restricting its expression to tumor cells. In transfection experiments, the hTERT promoter driven thymidine kinase gene (hTERTp/TK) conferred ganciclovir sensitivity to all tumor and immortal cell lines tested, whereas normal somatic cells remained largely unaffected. Human hTERTp/TK-positive cancer cells implanted in nude mice developed into tumors that could be eradicated by ganciclovir treatment. The hTERTp/TK cassette was inserted into an adenovirus vector and its efficacy in reducing tumor growth was compared with that of an adenovirus carrying the thymidine kinase gene under the control of the cytomegalovirus immediate-early promoter (CMVp/TK). In a xenograft model using the human 143B osteosarcoma cell line, a single injection of either virus resulted in equivalent tumor regression and survival upon ganciclovir treatment. In animals injected intratumorally with the CMVp/TK adenovirus, expression of the thymidine kinase gene was detected in tumors, as well as in liver samples. Expression of the suicide gene in combination with ganciclovir resulted in severe liver histopathology and in an elevation of hepatic enzymes. In sharp contrast, when the hTERT promoter controlled the thymidine kinase gene, transgene expression was observed in tumors, but not in liver samples. Normal liver function in these animals was confirmed by serum levels of hepatic enzymes that were indistinguishable from those of control healthy mice. These results indicate that by restricting thymidine kinase expression to tumor cells, the hTERT promoter allows the tumoricidal effect of the suicidal gene to be exerted without detrimental consequences on healthy tissues and vital organs. The tight specificity of expression imparted by the hTERT promoter will assist the development of novel approaches to the treatment of a broad array of cancer types.
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PMID:The telomerase reverse transcriptase promoter drives efficacious tumor suicide gene therapy while preventing hepatotoxicity encountered with constitutive promoters. 1131 24

The multisubstrate deoxyribonucleoside kinase of Drosophila melanogaster (Dm-dNK) can be expressed in human cells with retained enzymatic activity. The cells expressing Dm-dNK exhibit increased sensitivity to several cytotoxic nucleoside analogs. In this study, we further evaluated Dm-dNK as a potential novel suicide gene in combination with (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) as the prodrug. We used two human cancer cell lines transduced with a retrovirus encoding the Dm-dNK cDNA and investigated whether the cells expressing the enzyme can induce cell death of untransduced cells, a phenomenon known as the "bystander effect". A bystander effect was observed in a thymidine kinase-deficient human osteosarcoma cell line but not in the MIA PaCa-2 human pancreatic adenocarcinoma cell line. The cytotoxicity of BVDU increased in both cell lines when the compound was used in combination with subtoxic concentrations of hydroxyurea. Hydroxyurea also enhanced the bystander effect in the osteosarcoma cells, but not in the MIA PaCa-2 cells, treated with BVDU. These findings indicate that BVDU phosphorylated by Dm-dNK in transduced cancer cells may also induce bystander cell death in certain cell lines.
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PMID:Bystander effects of cancer cell lines transduced with the multisubstrate deoxyribonucleoside kinase of Drosophila melanogaster and synergistic enhancement by hydroxyurea. 1145 12

We have recently shown that the overexpression of Drosophila melanogaster multisubstrate deoxyribonucleoside kinase (Dm-dNK) in cancer cell lines increases the cells' sensitivity to several cytotoxic nucleoside analogs and the enzyme may accordingly be used as a suicide gene in combined gene/chemotherapy treatment of cancer. To further characterize the enzyme for possible use as a suicide gene, we constructed a replication-deficient retroviral vector that expressed either the wild-type enzyme that localizes to the cell nucleus or a mutant (arg247ser) that localizes to the cytosol. A thymidine kinase-deficient osteosarcoma cell line was transduced with the recombinant virus and we compared the sensitivity and bystander cell killing when the cell lines were incubated with the pyrimidine nucleoside analogs (E)-5-(2-bromovinyl)-2'-deoxyuridine and 1-beta-D-arabinofuranosylthymine. In summary, we showed that the cells' sensitivity and the efficiency of bystander cell killing were not dependent on whether Dm-dNK was located in the nucleus or cytosol.
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PMID:Nucleoside analog cytotoxicity and bystander cell killing of cancer cells expressing Drosophila melanogaster deoxyribonucleoside kinase in the nucleus or cytosol. 1170 4

Nucleoside kinases from several species are investigated as suicide genes for treatment of malignant tumors by combined gene/chemotherapy. In the present study, we have investigated a novel strategy where nucleoside kinase proteins are directly delivered to cells without delivery of genetic material. We used a mix of a trifluoroacetylated lipopolyamine and dioleoyl phosphatidylethanolamine (BioPorter) to form protein-lipid complexes containing either recombinant herpes simplex virus type-1 thymidine kinase or Drosophila melanogaster multisubstrate deoxyribonucleoside kinase. We showed that the nucleoside kinase containing protein-lipid complexes was imported into human osteosarcoma and Chinese hamster ovary cell lines by endocytosis and that the enzymes were delivered to the cytosol and nucleus. The nucleoside kinases imported into the cell lines retained enzymatic activity, and the cells treated with the enzyme-lipid complexes showed increased sensitivity to nucleoside analogues, such as ganciclovir, (E)-5-(2-bromovinyl)-2'-deoxyuridine, and 1-beta-D-arabinofuranosylthymine. Our results show that direct delivery of suicide gene proteins to cells may be an alternative approach to conventional suicide gene therapy strategies.
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PMID:Lipid-mediated protein delivery of suicide nucleoside kinases. 1458 90

Osteosarcoma and chondrosarcoma, the most prevalent primary malignant tumors of the bone, have been demonstrated to be potential target diseases for herpes simplex virus type 1 thymidine kinase (HSV-TK)/ganciclovir (GCV) suicide gene therapy. However, the utility of this gene therapy form for bone tumor cells has not been studied systematically. In this report we show, with the aid of three osteosarcoma cell lines (Saos-2, U-2-OS and MG-63) and one chondrosarcoma cell line (SW1353) that: i) these tumor cells were permissive for adenovirus- or lentivirus-mediated gene delivery; ii) the cell lines appeared to be good or excellent targets for HSV-TK/GCV gene therapy; and iii) the extent of HSV-TK/GCV cytotoxic effect correlated with the presence of the 'bystander effect' in these cells. Our results also suggest that lentiviruses are potential vectors for bone cancer gene therapy. They transduced all four cell lines with high efficiency and provided HSV-TK expression level that was sufficient for cytotoxicity and bystander effect comparable to that obtained with adenovirus vectors.
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PMID:Osteosarcoma and chondrosarcoma as targets for virus vectors and herpes simplex virus thymidine kinase/ganciclovir gene therapy. 1506 74


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