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

---

Query: EC:1.10.3.1 (tyrosinase)
9,065 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To target therapeutic genes specifically to melanoma cells, we have constructed recombinant retroviruses where transcriptional control of the murine interleukin-2 (mIL-2) or herpes simplex virus thymidine kinase (HSVtk) genes is provided by the 5' promoter region of the murine tyrosinase gene. Tissue-specific expression of these genes is observed both at the mRNA and protein levels in the B16 melanoma line compared with NIH3T3 fibroblasts. Thus, B16 cells infected with one such retrovirus containing the HSVtk gene exhibited a > 90% reduction in colony-forming efficiency after exposure to 1 microgram/ml ganciclovir, relative to controls, whereas similarly infected NIH3T3 cells showed < 10% reduction in colony-forming efficiency under comparable conditions. The degree of preservation of tissue-specific expression from the internal tyrosinase promoter depended upon the exact molecular design of the vector, possibly as a consequence of the interference between closely juxtaposed promoters within the provirus. Our results show that retroviral vectors can be prepared with the capacity to regulate expression of inserted genes specifically in a particular cell type and may be useful for developing efficient, targeted vectors for the in vivo delivery of genetic therapies for malignant melanoma.
...
PMID:A comparison of the properties of different retroviral vectors containing the murine tyrosinase promoter to achieve transcriptionally targeted expression of the HSVtk or IL-2 genes. 758 96

Sequence analysis of the promoter region of the murine tyrosinase gene identified various consensus motifs including AP2 sites, cAMP and TPA response elements (CREs/TREs) and retinoic acid response element (RARE) half-sites. By linking two different promoter lengths (2.5 kb or 769 bp) to murine interleukin-2 (IL-2) cDNA we have used IL-2 production by transduced B16 cells to monitor response to inducing agents capable of acting through these elements. Aminophylline or theophylline (0.1-2 mM) added to the culture medium of transfected B16, but not 3T3, cells, increased IL-2 secretion significantly (P > 0.05) in a dose-dependent fashion. This response was comparable in cells transfected with either the full length or the truncated promoter. Therefore, the cAMP responsiveness of the tyrosinase promoter probably is mediated by CREs and not AP2 sites, since the truncated promoter contains the former but not the latter regions. Retinoic acid at various concentrations (0.1-1 microM) evoked a standard increase in IL-2 production. Responses were similar for both promoter constructs, which suggests either that each RARE half-site can confer the full retinoic acid response, or that retinoic acid is mediating its effect through pathways independent of the RARE sites. TPA (2 nM-2 microM) had no effect on IL-2 production. These results demonstrate that the tyrosinase promoter can be induced by certain pharmacological agents and raise the possibility that administration of such substances may enhance expression of therapeutic genes controlled by this promoter.
...
PMID:Effects of modulators of tyrosinase activity on expression of murine interleukin-2 cDNA driven by the tyrosinase promoter. 762 Mar 42

The adoptive transfer of tumor-infiltrating lymphocytes (TILs) with interleukin-2 (IL-2) has antitumor activity in some patients with metastatic melanoma. We have analyzed molecular mechanisms of TIL recognition of human melanoma. Some cultured TILs specifically lysed autologous and some allogeneic melanomas sharing a variety of class I major histocompatibility complex (MHC) molecules. HLA-A2-restricted melanoma-specific TILs lysed many HLA-A2+ melanoma cell lines from different patients but failed to lyse HLA-A2- melanoma and HLA-A2+ nonmelanoma cell lines. However, these TILs were capable of lysing many naturally HLA-A2- melanomas after introduction of the HLA-A2.1 gene by vaccinia virus. These results indicate that shared melanoma antigens (Ag) are expressed in melanomas regardless of their human leukocyte antigen types. In order to identify these shared melanoma Ags, we have tested some known proteins expressed in melanoma. Expression of tyrosinase or HMB45 Ag correlated with lysis of TILs. We are also attempting to isolate antigenic peptides by high performance liquid chromatography separation and genes encoding melanoma Ag by cDNA expression cloning. The T-cell component of the antimelanoma response was also analyzed by determining the genetic structure of the T-cell receptor (TCR) used by melanoma TILs. However, we did not observe common TCR variable region usage by different melanoma TILs. We could establish melanoma cell clones and lines resistant to TIL lysis due to the absence of or defects in the expression of Ag, MHC, or beta 2-microglobulin molecules. These data indicate multiple mechanisms for melanoma escape from T-cell immunosurveillance.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:T-cell recognition of human melanoma antigens. 828 Jul 5

In the last 5 years significant progress has been made in our understanding of the molecular nature of anti-tumour T cell-mediated responses. This review describes the involvement of the cellular immune system in the recognition and destruction of cancer cells. Four aspects are discussed: (i) the generalized immune activation induced by the systemic administration of cytokines, in particular, interleukin-2; (ii) the specific T cell-mediated reactions against tumour cells through the recognition of tumour-associated molecules, 1) and tyrosinase proteins described in melanomas, and minor histocompatibility antigens in the setting of allogenic bone marrow transplantation for leukaemia; (iii) the potentially significant but still hypothetical immune-mediated recognition of molecules either tumour-associated or transformation-related (including altered oncogenic proteins); and (iv) the role of co-stimulatory molecules in the induction of tumour-specific immunity. The current and future therapeutic applications in cancer treatment and potential limitations in this approach are discussed.
...
PMID:The role of the immune system in anti-tumour responses. Potential for drug therapy. 853 54

Melanin biosynthesis is restricted to melanocytes partly as a consequence of transcriptional regulation of the mRNA coding for those enzymes involved in this biochemical pathway. Promoter sequences of these genes may be used to regulate expression of complementary DNA coding for therapeutic genes so as to provide transcriptional targeting. As a model system we have used the 5'-flanking sequences of the murine tyrosinase or tyrosinase-related protein 1 (TRP-1) genes to show that such transcriptional targeting can be accomplished both in vitro and in vivo. Using interleukin-2 (IL-2) as an example of an immunostimulatory gene and herpes simplex virus thymidine kinase (HSVTK), as an example of a prodrug-activating gene we have shown, in murine model systems, that marked antitumour effects can be achieved by targeted gene therapy approaches. Because other tumor types produce particular proteins as a consequence of specific transcription it is possible that this approach may provide a way of targeting therapeutic genes to various cancers.
...
PMID:Tissue specific promoters in targeting systemically delivered gene therapy. 860 25

We have immunized advanced melanoma patients with a HLA-A2-compatible human melanoma line genetically modified to release interleukin-2 (IL-2), to elicit or increase a T cell-mediated anti-melanoma response that may affect distant lesions. Twelve stage-IV patients were injected subcutaneously at days 1, 13, 26, and 55 with IL-2 gene-transduced and irradiated melanoma cells at doses of 5 or 15 x 10(7) cells. Both local and systemic toxicities were mild, consisting of transient erythema at the vaccination site; fever occurred in a minority of patients. Three mixed responses were recorded. Seven patients were evaluable for immunological studies. Mixed tumor-lymphocyte cultures carried out with different allogeneic HLA-A2-matched melanoma lines as stimulators and targets revealed an increase in the MHC-unrestricted, but no changes in the MHC-restricted, cytotoxicity in peripheral blood lymphocytes (PBL) obtained after vaccination as compared with those obtained before vaccination. Increased recognition of the tyrosinase 368-376 peptide occurred in post-vaccination PBL of one patient, whereas a weak increase in recognition of the gp100 280-288 peptide was detectable in another patient; these 2 patients also recognized the gp100 457-466 peptide. After in vitro, stimulation with the only available autologous melanoma line, CD4+ cells with autologous tumor-specific cytotoxicity and ability to release interferon-gamma (IFN-gamma) were found in post- but not in pre-vaccination PBL. In the same patient, as well as in another patient, limiting dilution analysis showed that vaccination resulted in an increased frequency of melanoma-specific cytotoxic T lymphocyte (CTL) precursors. These results indicate that vaccination with cells releasing IL-2 locally can expand a T cell response against antigen(s) of autologous, untransduced tumor, although this response occurred in a minority of the melanoma patients studied.
...
PMID:Limited antitumor T cell response in melanoma patients vaccinated with interleukin-2 gene-transduced allogeneic melanoma cells. 893 Jun 55

We have established a sensitive ELISPOT assay measuring interferon gamma (IFN gamma) release on a single-cell basis to detect influenza peptide-specific CD8+ T cells in uncultured peripheral blood mononuclear cells (PBMC). Using this method, we studied the T cell response to HLA-A1 and HLA-A2.1 binding peptide epitopes derived from the MAGE-1 and MAGE-3 proteins, from the melanoma-associated antigens tyrosinase, Melan-A/MART-1 and gp100, and from influenza proteins in stage IV melanoma patients and healthy controls. In 18 of 24 HLA-A2-positive donors (75%), but only in 9 of 25 HLA-A2-positive melanoma patients (36%) T cells reactive with the influenza matrix peptide were demonstrated (p = 0.007). T cells responding to one or several of the melanoma-associated peptides were detected in 5 of 25 HLA-A2-positive patients with metastatic melanoma. Four of these 5 patients had been treated with interleukin-2- and IFN alpha-containing therapy. Two of the 24 healthy donors had T cells reactive with the MART-1 27-35 peptide. No reactivity with the HLA-A1-binding peptides from MAGE-1 or MAGE-3 was detected in any of the HLA-A1-positive healthy controls or melanoma patients. These results show that the IFN gamma-ELISPOT assay is suitable to determine quantitatively T cells reactive with melanoma-associated and influenza peptide epitopes in uncultured PBMC. The failure to detect T cells responding to influenza in many melanoma patients with progressive disease may indicate an impairment of their T cell function.
...
PMID:Analysis of the T cell response to tumor and viral peptide antigens by an IFNgamma-ELISPOT assay. 918 91

A cell line (UISO-H-MEL-2) was established from the neoplastic cells of a patient with malignant melanoma during the natural course of the patient's treatment. The melanoma cells express defined MHC Class I histocompatibility determinants including determinants specified by the HLA-A2 Class I allele, along with a common melanoma-associated T-cell epitope derived from the tyrosinase gene. The gene for human interleukin-2 (IL-2) was transduced into the cells with a provirus (pZipNeoSVIL-2), packaged in GP + envAM12 cells. Integration of the IL-2 gene into genomic DNA of the transduced cells and its expression were established. The IL-2-secreting cell line (UISO-H-MEL-2-IL-2) was found to be free of recombinant retroviruses and other infectious agents. The IL-2-secreting cells will be subjected to 5000 rads X-irradiation and administered to 12 informed patients with metastatic malignant melanoma in a Phase I toxicity study. The dose of X-irradiation was sufficient to inactivate one hundred percent of the cells, but insufficient to completely inhibit IL-2 synthesis during a fourteen-day period of analysis. Patients who have failed all standard forms of treatment will become eligible for inclusion in the study if they develop metastatic melanoma, and if their tumor cells express products of the tyrosinase gene. The patients will differ with the cellular immunogen at no less than three of six MHC Class I alleles, but will share identity at the HLA-A2 Class I allele. The patient's antimelanoma immune response to the injected cells will be determined by both in vivo and in vitro parameters. Background studies performed in inbred mice indicate that X-irradiated IL-2-secreting cells that express both melanoma-associated antigens and allogeneic Class I histocompatibility antigens are more antigenic in terms of their capacity to induce an antimelanoma response than X-irradiated IL-2-secreting melanoma cells. Of significance for the future potential of this form of therapy in melanoma patients, the period of survival of mice was established melanoma treated with the IL-2-secreting allogeneic cells was significantly (P < 0.001) longer than that of untreated animals, or animals treated with X-irradiated melanoma cells. An analogous protocol was reviewed and approved by the Recombinant DNA Advisory Committee of the National Institutes of Health.
...
PMID:Phase I evaluation of interleukin-2-transfected irradiated allogeneic melanoma for the treatment of metastatic melanoma: appendix 1: protocol. 932 73

We have transfected human melanoma cell line 518A2 with the cDNA encoding interleukin-2 (IL-2) or granulocyte-macrophage colony-stimulating factor (GM-CSF), and compared cytokine-producing clones for their ability to induce melanoma-specific cytotoxic T lymphocytes (CTL) from autologous peripheral blood mononuclear cells (PBMC) in vitro. The parental cell line expressed HLA-A1, HLA-A2, ICAM-1, LFA-3, in addition to the common CTL antigens MAGE-1, MAGE-3, tyrosinase, gp100, and Melan-A/MART-1. Stimulation of autologous PBMC responders with the IL-2-transfected clone 518/IL2.14 specifically induced CTL lines reactive with all cell lines derived from the autologous patient. Strikingly, GM-CSF-transfected 518A2 cells did not induce anti-tumor CTL reactivity. CTL induction against 518/IL2.14 was independent of HLA class II expression or CD4 help. The parental cell line 518A2 gained immunogenic properties when high concentrations of IL-2 were supplied exogenously, indicating that IL-2 produced and present at high levels locally by itself enhanced immunogenicity. From the autologous CTL line reactive with 518/IL2.14, clones were generated against an as yet unknown antigen, which was present in all autologous melanoma cell lines as well as in 7 of 15 HLA-A2+ melanoma cell lines tested, but not in melanocytes. These results will be discussed with respect to the possibility of using IL-2-transfected melanoma cells as a vaccine for treatment of patients with melanoma.
...
PMID:Transfection of IL-2 augments CTL response to human melanoma cells in vitro: immunological characterization of a melanoma vaccine. 933 41

We have shown the presence of tyrosinase-reactive T cells in the peripheral blood of melanoma patients, who had been in remission after treatment with IL-2-containing regimens. In this consecutive study, we analyzed the T-cell response to various peptides derived from tyrosinase in serial blood samples obtained from 7 stage-IV melanoma patients before, during and following treatment. All patients were treated within a randomized trial (EORTC 18951) with cisplatin (CDDP), dacarbazine (DTIC), interferon-alpha (IFN-alpha) +/- interleukin-2 (IL-2). Using an ELISPOT assay detecting peptide-specific IFN-gamma release, we measured the T-cell response to 4 different HLA class I-binding peptide epitopes derived from tyrosinase containing an HLA-A2.1-, HLA-A24- or HLA-B44-binding motif in peripheral-blood mononuclear cells (PBMC). In one patient, tyrosinase-reactive T cells were detected before therapy. In 4 out of 7 patients, tyrosinase-reactive T cells against both HLA-A2.1-binding peptides and the B44-binding peptide became detectable at frequencies of up to 30 in 5 x 10(5) lymphocytes following treatment. These patients received CDDP, DTIC and IFN-alpha, 2 of them without IL-2 and 2 with IL-2, resulting in one complete remission and 3 partial remissions. Two patients relapsed 8 and 9 months after treatment. At the time of relapse, no T cells reactive with tyrosinase were detectable. Our results show that high frequencies of tyrosinase-reactive T cells in the peripheral blood of melanoma patients can be induced by chemotherapy in combination with IFN-alpha, regardless of concomitant IL-2 administration.
...
PMID:Induction of tyrosinase-reactive T cells by treatment with dacarbazine, cisplatin, interferon-alpha +/- interleukin-2 in patients with metastatic melanoma. 993 27


1 2 Next >>

---