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

Transcriptional activity of the 5'-flanking sequence of the human gamma-glutamylcysteine synthetase heavy subunit (gamma-GCSh) gene was investigated in COS7 cells transfected with hGH reporter constructs having successively deleted 5'-flanking sequence of the gamma-GCSh gene. Transcriptional activity was determined by the amounts of hGH secreted from the reporter constructs. Deletion of the sequence from -1,413 to -664 or -315 base pairs (bp) increased transcriptional activity from 100 to 138 or 136%. Further deletion from -315 to -241 bp, which contained an AP1 site, decreased transcriptional activity to 87%. Mutations introduced into the AP1 decreased transcriptional activity from 136 to 105%. These findings suggested that the AP1 increased transcriptional activity. When the sequence from -241 to -192 bp was deleted, transcriptional activity was restored from 87 to 128%. When this sequence was linked to the thymidine kinase promoter, it also decreased transcriptional activity by 38%. Deletion from -192 to -149, -116, or -108 bp did not significantly alter transcriptional activity. Further deletion of the GC-rich sequences from -108 to -70 and -28 bp dramatically decreased transcriptional activity from 135 to 87 and 34%, respectively. These findings indicate that multiple DNA elements, especially those in the proximal GC-rich sequences, are involved in the regulation of transcriptional activity of the gamma-GCSh gene.
 ...
PMID:Identification of cis-acting DNA elements of the human gamma-glutamylcysteine synthetase heavy subunit gene. 912 14

The contribution of the 5'-flanking sequence of the human gamma-glutamylcysteine synthetase heavy subunit (gamma-GCSh) gene to cisplatin-induced transcriptional up-regulation was studied using various human growth hormone reporter constructs which were transfected to a human lung cancer cell line SBC-3. Cisplatin at the concentration of 3 microM increased the transcriptional activity of the longest sequence from -1,413 to +91 bp of the gamma-GCSh gene to 246% of that in non-exposed cells. The distal sequence from -1,413 to -193 bp was shown to negatively regulate transcriptional activity in both cisplatin-exposed and non-exposed cells using deletion and thymidine kinase (TK) promoter-linked constructs. Cisplatin increased the transcriptional activity of the proximal GC-rich sequence from -192 to +91 bp to 340%, of which magnitude was the maximum among deletion constructs. A deletion from -108 to -28 bp, or +34 to +91 bp significantly decreased cisplatin-induced increases in transcriptional activity from 258 to 105%, or 340 to 160%, respectively. When the sequence from -108 to -22 bp, or +26 to +91 bp was linked to the heterologous TK promoter, cisplatin increased the transcriptional activity to 171 or 181%, respectively, from that of 128 or 137%, respectively, in non-exposed cells. These findings indicate that the proximal sequence from -192 to +91 bp of the gamma-GCSh gene, especially from -108 to -28 bp, and +34 to +91 bp, is involved in cisplatin-induced transcriptional up-regulation in SBC-3 cells.
 ...
PMID:Proximal 5'-flanking sequence of the human gamma-glutamylcysteine synthetase heavy subunit gene is involved in cisplatin-induced transcriptional up-regulation in a lung cancer cell line SBC-3. 924 99

Efficient ex vivo/in vivo selection of genetically modified hematopoietic stem/progenitor cells (HPCs) and T lymphocytes could greatly improve several gene therapy strategies. We have previously reported that primary murine HPCs, transduced with a bicistronic retroviral vector, co-expressing the catalytic subunit of gamma-glutamylcysteine synthetase (gamma-GCSh) and eGFP, could be selected by l-buthionine-S,R-sulfoximine (BSO). Upon ex vivo transduction with a low, defined gene dosage and BSO selection, HPCs were able to repopulate the bone marrow of syngeneic myeloablated hosts, showing multi-lineage expression [Hum Gene Ther, 16 (2005), 711]. We now provide 'proof-of-principle' that the same strategy can be applied to the gene therapy of graft-vs.-host disease (GVHD) subsequent to allogeneic bone marrow transplantation (ABMT), and of chromosome X-associated chronic granulomatous disease (CGD). Transfer of the herpes simplex virus-thymidine kinase (HSV-Tk) 'suicide' gene into donor T lymphocytes is a potential method to control GVHD after ABMT. However, an efficient selection system is required to eliminate non-HSV-Tk-expressing T lymphocytes before administration to the patient. We now report that, upon transduction with a retroviral vector, co-expressing gamma-GCSh and eGFP, and subsequent selection by BSO, over 95% human T lymphocytes were found to express eGFP; moreover, upon transduction with a novel retroviral vector co-expressing gamma-GCSh and HSV-Tk, and subsequent BSO treatment, over 95% of T lymphocytes could be eliminated by ganciclovir. The efficacy of the gamma-GCSh-BSO selection strategy was then tested on an in vitro model of CGD. Upon transduction of gp91 (phox)-deficient PLBKO cells with a novel bicistronic retroviral vector co-expressing human gp91 (phox) and gamma-GCSh, exposure to BSO for 48 h eliminated most non-transduced cells, resulting in selection of gp91 (phox)-expressing cells, and reconstitution of NADPH oxidase activity.
 ...
PMID:Gamma-glutamylcysteine synthetase-based selection strategy for gene therapy of chronic granulomatous disease and graft-vs.-host disease. 1733 Nov 33