Regulation of human deoxycytidine kinase expression

doi:10.1016/0065-2571(93)90009-3

Advances in Enzyme Regulation

Volume 33, 1993, Pages 61-62

https://doi.org/10.1016/0065-2571(93)90009-3 Get rights and content

Abstract

The human deoxycytidine kinase gene is a single copy gene and is comprised of seven exons that are spread over more than 34 kb of the genome. The 5′-flanking region is highly G/C rich and does not contain CAAT or TATA boxes. This region, when cloned into a recorder gene contruct containing the chloramphenicol acetyltransferase gene, is capable of mediating CAT activity in human lymphoid cell lines and appears to have greater activity in human T, as compared to B, lymphoblast cell lines. The expression of the gene at the mRNA level does not appear to be cell-cycle regulated in that the levels of mRNA in human peripheral blood T lymphocytes remain constant as the cells progress from a resting to a proliferating state. Since this enzyme catalyzes the conversion of a number of chemotherapeutic agents to their corresponding monophosphate form and is thus essential for their activation, it will be important to define further the genetic elements which regulate the expression of this gene.

References (27)

L.D. Piro
2-Chlorodeoxyadenosine treatment of lymphoid malignancies
Blood
(1992)
N.S. Datta et al.
Kinetic properties and inhibition of human T lymphoblast deoxycytidine kinase
J. Biol. Chem.
(1989)
T.A. Krenitsky et al.
Deoxycytidine kinase from calf thymus: substrate and inhibitor specificity
J. Biol. Chem.
(1976)
Y.K. Kim et al.
Identification of a protein-binding site in the promoter of the human thymidine kinase gene required for the G1-S-regulated transcription
J. Biol. Chem.
(1992)
E.S. Arner et al.
Deoxycytidine kinase is constitutively expressed in human lymphocytes: consequences for compartmentation effects, unscheduled DNA synthesis, and viral replication in resting cells
Exptl. Cell Res.
(1988)
R.J. Harkrader et al.
Increase in liver and kidney deoxycytidine kinase activity linked to neoplastic transformation
Biochem. Biophys. Res. Commun.
(1980)
D.W. Kufe et al.
Biochemical and cellular pharmacology of cytosine arabinoside
Sem. Oncol.
(1985)
W. Plunkett et al.
Comparison of the toxicity and metabolism of 9-β-d-arabinofuranosyl-2-fluoroadenine and 9-β-d-arabinofuranosyladenine in human lymphoblastoid cells
Cancer Res.
(1980)
W. Plunkett et al.
2′,2′-Difluorodeoxycytidine metabolism and mechanism of action in human leukemic cells
Nucleosides Nucleotides
(1989)
C. Bohman et al.
Deoxycytidine kinase from human leukemic spleen: preparation and characteristics of homogeneous enzyme
Biochemistry
(1988)

N.S. Datta et al.

Human T-lymphoblast deoxycytidine kinase: purification and properties

Biochemistry

(1989)

E.G. Chottiner et al.

Cloning and expression of human deoxycytidine kinase

P.T. Harrison et al.

Evolution of herpesvirus thymidine kinases from cellular deoxycytidine kinase

J. Gen. Virol.

(1991)

Cited by (19)

Relationship between deoxycytidine kinase (DCK) genotypic variants and fludarabine toxicity in patients with follicular lymphoma
2011, Leukemia Research
Citation Excerpt :
These analyses showed an association between C28624T variant and neutropenia, both for FCR period (log rank test, P = 0.014) (Fig. 2) and, for FCR and maintenance/follow-up periods (log rank test, P = 0.016). DCK activity is regulated at transcriptional and post-transcriptional levels [4,24–27]. Genetic alterations may occur at the DNA or RNA level and lead to decreased expression [6–9,28,29].
DCK catalyzes the intracellular phosphorylation of fludarabine. The promoter and coding region of the DCK gene were analyzed in 74 follicular lymphoma (FL) patients receiving a therapeutic regimen that included fludarabine. DCK mRNA expression was quantified in a cohort of healthy donors. Four previously described genotypic variants, −360C>G, −201C>T (rs2306744), C28624T (rs11544786) and c.91+37G>C (rs9997790), as well as the new variant, −12C>G, were identified. Variant C28624T showed a lower risk of lymphopenia (P = 0.04), but a higher risk of neutropenia (P = 0.04). Statistical significance was found in bivariate logistic regression between lymphopenia and infectious episodes in the induction period (odds ratio 3.85, P = 0.04).
Docking simulation with a purine nucleoside specific homology model of deoxycytidine kinase, a target enzyme for anticancer and antiviral therapy
2005, Bioorganic and Medicinal Chemistry
5′-Phosphorylation, catalyzed by human deoxycytidine kinase (dCK), is a crucial step in the metabolic activation of anticancer and antiviral nucleoside antimetabolites, such as cytarabine (AraC), gemcitabine, cladribine (CdA), and lamivudine. Recently, crystal structures of dCK (dCKc) with various pyrimidine nucleosides as substrates have been reported. However, there is no crystal structure of dCK with a bound purine nucleoside, although purines are good substrates for dCK. We have developed a model of dCK (dCKm) specific for purine nucleosides based on the crystal structure of purine nucleoside bound deoxyguanosine kinase (dGKc) as the template. dCKm is essential for computer aided molecular design (CAMD) of novel anticancer and antiviral drugs that are based on purine nucleosides since these did not bind to dCKc in our docking experiments. The active site of dCKm was larger than that of dCKc and the amino acid (aa) residues of dCKm and dCKc, in particular Y86, Q97, D133, R104, R128, and E197, were not in identical positions. Comparative docking simulations of deoxycytidine (dC), cytidine (Cyd), AraC, CdA, deoxyadenosine (dA), and deoxyguanosine (dG) with dCKm and dCKc were carried out using the FlexX™ docking program. Only dC (pyrimidine nucleoside) docked into the active site of dCKc but not the purine nucleosides dG and dA. As expected, the active site of dCKm appeared to be more adapted to bind purine nucleosides than the pyrimidine nucleosides. While water molecules were essential for docking experiments using dCKc, the absence of water molecules in dCKm did not affect the ability to correctly dock various purine nucleosides.
Transcriptional regulation of the mouse deoxycytidine kinase: Identification and functional analysis of nuclear protein binding sites at the proximal promoter
2004, Biochemical Pharmacology
Citation Excerpt :
The kinetic regulatory mechanisms of this enzyme have been established [9–11], and recently, the crystal structure has been determined [12]. A relatively constant amount of the dCK protein in proliferating and resting lymphocytes suggests that its expression is not strictly cell cycle regulated [10,13]. On the other hand, dCK was found to be expressed predominately in lymphoid tissues, which indicates a cell type-specific regulation of the gene [1,10].
Deoxycytidine kinase (EC 2.7.1.74, dCK) catalyzes the phosphorylation of deoxynucleosides and several nucleoside analogues that are important in antiviral and cancer chemotherapy. The enzyme is predominantly expressed in lymphoid tissue by as yet poorly defined mechanisms. In this work, we have studied the mouse dCK regulatory region to understand the molecular details of the tissue specific expression of the enzyme. DNase I footprinting and electrophoretic mobility shift assays using nuclear extracts from mouse lymphocytes (EL-4, T cells; J558, B cells) and non-lymphoid cells (L929, fibroblasts) demonstrated the existence of at least six cis-acting elements (FP-1–FP-6) within the proximal promoter region. Functional analysis revealed that all the elements necessary to promote high level transcription of the mdCK gene are located downstream the transcription start site. 5′-Deletion and site-directed mutagenesis assays demonstrated the importance of four GC-rich regions, which bind Sp-1 and Sp-3 transcription factors. In addition, we identified a site (FP-3) located at the −282 to −310 nucleotide region of the promoter, which binds NF-1, only in B cells. Analysis of point mutations introduced at the different regions revealed functional differences in their role in mdCK transcription in the cell lines used.
Activation of deoxycytidine kinase by protein kinase inhibitors and okadaic acid in leukemic cells
2004, Biochemical Pharmacology
Citation Excerpt :
Studies of the mechanism(s) that control the activity of this enzyme are thus of particular interest. In contrast to thymidine kinase 1, also a deoxynucleoside salvage enzyme, dCK is not cell-cycle regulated, although some variations in its activity have been observed during the progression of the cell cycle [14–16]. Physiologically, dCK activity could be down-regulated by dCTP.
Deoxycytidine kinase (dCK) is a key enzyme in the deoxynucleoside salvage pathway and in the activation of numerous nucleoside analogues used in cancer and antiviral chemotherapy. Recent studies indicate that dCK activity might be regulated through reversible phosphorylation. Here, we report the effects of a large panel of protein kinase inhibitors on dCK activity in the B-leukemia cell line EHEB, both in basal conditions and in the presence of the nucleoside analogue 2-chloro-2′-deoxyadenosine (CdA) which induces activation of dCK. Except staurosporine and H-7 that significantly reduced the activation of dCK by CdA, no specific protein kinase inhibitor diminished basal dCK activity or its activation by CdA. In contrast, genistein, a general protein tyrosine kinase inhibitor, and AG-490, an inhibitor of JAK2 and JAK3, increased basal dCK activity more than two-fold. Two specific inhibitors of the MAPK/ERK pathway, PD-98059 and U-0126, also enhanced dCK activity. These data suggest that the JAK/MAPK pathway could be involved in the regulation of dCK. Moreover, we show that the activity of dCK, raised by CdA, can return to its initial level by treatment with protein phosphatase-2A (PP2A). Accordingly, dCK activity in intact cells increased upon incubation with okadaic acid (OA) at concentrations that should inhibit PP2A, but not protein phosphatase-1. Activation of dCK by protein kinase inhibitors and OA was also observed in CCRF-CEM cells and in chronic lymphocytic leukemia B-lymphocytes, suggesting a general mechanism of post-translational regulation of dCK, which could be exploited to enhance the activation of antileukemic nucleoside analogues.
Selective activation of deoxycytidine kinase by thymidine-5′-thiosulphate and release by deoxycytidine in human lymphocytes
2003, Biochemical Pharmacology
Citation Excerpt :
The most widely used antimetabolites are: 2-chloro-2′-deoxyadenosine (Cladribine) [3], 2′,2′-difluorodeoxycytidine (Gemcitabine) and 1-β-d-arabinosylcytosine as antiproliferative agents [3] or 3′-azido-2′,3′-dideoxythymidine and (S,S)-isodideoxyadenosine as powerful compounds against HIV infection [4,5]. dCK is located in the proximity of the cytoplasmic membrane as well as in the perinuclear area [6] and shows a constitutive expression throughout the cell cycle [6–8], although 2- to 3-fold differences in its activity have been reported in different phases of the cell cycle [8]. Especially in resting cells, such as G0/G1 phase lymphocytes, thymocytes and splenocytes and central neurons, its contribution to DNA repair and membrane liponucleotide synthesis is indispensable [9,10].
Deoxycytidine kinase (dCK) catalyses the rate-limiting step of the salvage of three natural deoxyribonucleosides as well as several therapeutic nucleoside analogues, which in turn can enhance its enzymatic activity [Biochem Pharmacol 56 (1998) 1175], improving the efficacy of the cytostatic therapy. Here, we measured the effect of the 5′-thiosulphate (5′-TS) derivatives of four deoxyribonucleosides (deoxyadenosine, deoxycytidine (dCyd), azidothymidine, thymidine) and two ribonucleosides (ribopurine, ribouridine (Urd)) on the activity of the two main salvage deoxynucleoside kinases, and on the salvage of dCyd and deoxythymidine (dThd). It turned out that only 2′-deoxythymidine-5′-thiosulphate (dThd-5′-TS) can potentiate the dCK activity, without influencing the thymidine kinase isoenzymes during short-time treatments of human peripheral blood and tonsillar lymphocytes. The enhancement of dCK activity by dThd-5′-TS can be reversed by dCyd, but dThd had no effect on the enzyme activation in cells. Neither dThd-5′-TS nor Urd-5′-TS had any effect on the dCK and thymidine kinase activities tested in cell-free extracts. The stimulation of dCK activity in cells was accompanied by an imbalance in the dThd and dCyd metabolism. The incorporation of $^{3} H$ -dThd into DNA was suppressed by 90% in cells by dThd-5′-TS, while Urd-5′-TS only slightly influenced the same process. The $^{3} H$ -dCyd incorporation into DNA was inhibited only to 50% of the control, while the $^{3} H$ -dCyd labelling of the nucleotide fraction was enlarged in dThd-5′-TS-treated cells, as a consequence of the increased dCK activity. We suggest that the enhancement of dCK activity is a compensatory mechanism in cells that might be induced by different “inhibitors” of DNA synthesis leading to damage of DNA. The increased dCK activity is able to supply the repair of DNA with dNTPs in quiescent cells; this suggestion seems to be supported by the counteracting effect of extracellular dCyd, too.
The use of boron clusters in the rational design of boronated nucleosides for neutron capture therapy of cancer
2000, Journal of Organometallic Chemistry
Citation Excerpt :
Unlike TK1, dCK is not cell cycle regulated. It is expressed by a wide variety of cell types [53–57]. Various malignant tumors showed a two- to five-fold increase of dCK levels compared to the corresponding normal tissues [35,57–60].
Boron neutron capture therapy (BNCT) is a chemoradio–therapeutic method for the treatment of cancer. It depends on the selective targeting of tumor cells by boron-containing compounds. One category of BNCT agents that has received extensive attention during recent years is boronated nucleosides. Such structures may be converted to the corresponding 5′-monophosphates by phosphorylating enzymes and thereby entrapped in tumor cells by the virtue of the acquired negative charge. This review analyzes previous design strategies applied in the synthesis of boron cluster-containing nucleosides and discusses possible future developments in this field based on existing knowledge of enzyme tissue expressions, enzyme substrate specificities, and contemporary trends in rational drug design.

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Regulation of human deoxycytidine kinase expression

Abstract

Blood

J. Biol. Chem.

J. Biol. Chem.

J. Biol. Chem.

Exptl. Cell Res.

Biochem. Biophys. Res. Commun.

Biochemical and cellular pharmacology of cytosine arabinoside

Sem. Oncol.

Comparison of the toxicity and metabolism of 9-β-d-arabinofuranosyl-2-fluoroadenine and 9-β-d-arabinofuranosyladenine in human lymphoblastoid cells

Cancer Res.

2′,2′-Difluorodeoxycytidine metabolism and mechanism of action in human leukemic cells

Nucleosides Nucleotides

Deoxycytidine kinase from human leukemic spleen: preparation and characteristics of homogeneous enzyme

Biochemistry

Human T-lymphoblast deoxycytidine kinase: purification and properties

Biochemistry

Cloning and expression of human deoxycytidine kinase

Evolution of herpesvirus thymidine kinases from cellular deoxycytidine kinase

J. Gen. Virol.