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Yehia H, Westarp S, Röhrs V, Kaspar F, Giessmann RT, Klare HF, Paulick K, Neubauer P, Kurreck J, Wagner A. Efficient Biocatalytic Synthesis of Dihalogenated Purine Nucleoside Analogues Applying Thermodynamic Calculations. Molecules 2020; 25:E934. [PMID: 32093094 PMCID: PMC7070685 DOI: 10.3390/molecules25040934] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/16/2020] [Accepted: 02/18/2020] [Indexed: 02/07/2023] Open
Abstract
The enzymatic synthesis of nucleoside analogues has been shown to be a sustainable and efficient alternative to chemical synthesis routes. In this study, dihalogenated nucleoside analogues were produced by thermostable nucleoside phosphorylases in transglycosylation reactions using uridine or thymidine as sugar donors. Prior to the enzymatic process, ideal maximum product yields were calculated after the determination of equilibrium constants through monitoring the equilibrium conversion in analytical-scale reactions. Equilibrium constants for dihalogenated nucleosides were comparable to known purine nucleosides, ranging between 0.071 and 0.081. To achieve 90% product yield in the enzymatic process, an approximately five-fold excess of sugar donor was needed. Nucleoside analogues were purified by semi-preparative HPLC, and yields of purified product were approximately 50% for all target compounds. To evaluate the impact of halogen atoms in positions 2 and 6 on the antiproliferative activity in leukemic cell lines, the cytotoxic potential of dihalogenated nucleoside analogues was studied in the leukemic cell line HL-60. Interestingly, the inhibition of HL-60 cells with dihalogenated nucleoside analogues was substantially lower than with monohalogenated cladribine, which is known to show high antiproliferative activity. Taken together, we demonstrate that thermodynamic calculations and small-scale experiments can be used to produce nucleoside analogues with high yields and purity on larger scales. The procedure can be used for the generation of new libraries of nucleoside analogues for screening experiments or to replace the chemical synthesis routes of marketed nucleoside drugs by enzymatic processes.
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Affiliation(s)
- Heba Yehia
- Chair of Bioprocess Engineering, Faculty III Process Sciences, Institute of Biotechnology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany; (H.Y.); (S.W.); (F.K.); (R.T.G.); (K.P.); (P.N.)
- Chemistry of Natural and Microbial Products Department, Pharmaceutical and Drug Industries Research Division, National Research Centre, Dokki, 12622 Cairo, Egypt
| | - Sarah Westarp
- Chair of Bioprocess Engineering, Faculty III Process Sciences, Institute of Biotechnology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany; (H.Y.); (S.W.); (F.K.); (R.T.G.); (K.P.); (P.N.)
- BioNukleo GmbH, Ackerstr. 76, 13355 Berlin, Germany
| | - Viola Röhrs
- Chair of Applied Biochemistry, Faculty III Process Sciences, Institute of Biotechnology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany; (V.R.); (J.K.)
| | - Felix Kaspar
- Chair of Bioprocess Engineering, Faculty III Process Sciences, Institute of Biotechnology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany; (H.Y.); (S.W.); (F.K.); (R.T.G.); (K.P.); (P.N.)
- BioNukleo GmbH, Ackerstr. 76, 13355 Berlin, Germany
| | - Robert T. Giessmann
- Chair of Bioprocess Engineering, Faculty III Process Sciences, Institute of Biotechnology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany; (H.Y.); (S.W.); (F.K.); (R.T.G.); (K.P.); (P.N.)
| | - Hendrik F.T. Klare
- Faculty II Mathematics and Natural Sciences, Institute of Chemistry, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany;
| | - Katharina Paulick
- Chair of Bioprocess Engineering, Faculty III Process Sciences, Institute of Biotechnology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany; (H.Y.); (S.W.); (F.K.); (R.T.G.); (K.P.); (P.N.)
| | - Peter Neubauer
- Chair of Bioprocess Engineering, Faculty III Process Sciences, Institute of Biotechnology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany; (H.Y.); (S.W.); (F.K.); (R.T.G.); (K.P.); (P.N.)
| | - Jens Kurreck
- Chair of Applied Biochemistry, Faculty III Process Sciences, Institute of Biotechnology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany; (V.R.); (J.K.)
| | - Anke Wagner
- Chair of Bioprocess Engineering, Faculty III Process Sciences, Institute of Biotechnology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany; (H.Y.); (S.W.); (F.K.); (R.T.G.); (K.P.); (P.N.)
- BioNukleo GmbH, Ackerstr. 76, 13355 Berlin, Germany
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Dennison JB, Ayres ML, Kaluarachchi K, Plunkett W, Gandhi V. Intracellular succinylation of 8-chloroadenosine and its effect on fumarate levels. J Biol Chem 2010; 285:8022-30. [PMID: 20064937 DOI: 10.1074/jbc.m109.085803] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
8-Chloroadenosine (8-Cl-Ado) is a ribosyl nucleoside analog currently in phase I testing for the treatment of chronic lymphocytic leukemia (CLL). 8-Cl-Ado activity is dependent on adenosine kinase and requires intracellular accumulation of 8-Cl-Ado as mono-, di-, and tri-phosphates. In the current study with four mantle cell lymphoma cell lines, we report a new major metabolic pathway for 8-Cl-Ado intracellular metabolism, the formation of succinyl-8-chloro-adenosine (S-8-Cl-Ado) and its monophosphate (S-8-Cl-AMP). 8-Cl-AMP levels were highly associated with S-8-Cl-AMP levels and reached a steady-state prior to the secondary metabolites, 8-Cl-ATP and S-8-Cl-Ado. Consistent with fumarate as a required substrate for formation of succinyl-8-Cl-adenylate metabolites, the S-8-Cl-adenylate concentrations in multiple cell lines were associated with fumarate loss. The distribution of metabolites was also altered using the energy metabolism modifiers, metformin and oligomycin. The rates of succinyl-8-Cl-adenylate metabolism were enhanced by increasing the intracellular fumarate concentrations after metformin co-treatment. In addition, the S-8-Cl-AMP concentrations were increased after acute inhibition of ATP synthase by oligomycin. We conclude that 8-Cl-Ado metabolism not only affects intracellular purine metabolism; 8-Cl-Ado conversion to succinyl analogs ties its metabolism to the citric acid cycle by reduction of the fumarate pool.
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Affiliation(s)
- Jennifer B Dennison
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
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Robinson-White AJ, Hsiao HP, Leitner WW, Greene E, Bauer A, Krett NL, Nesterova M, Stratakis CA. Protein kinase A-independent inhibition of proliferation and induction of apoptosis in human thyroid cancer cells by 8-Cl-adenosine. J Clin Endocrinol Metab 2008; 93:1020-9. [PMID: 18073299 PMCID: PMC2266951 DOI: 10.1210/jc.2007-2331] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE Protein kinase A (PKA) affects cell proliferation in many cell types and is a potential target for cancer treatment. PKA activity is stimulated by cAMP and cAMP analogs. One such substance, 8-Cl-cAMP, and its metabolite 8-Cl-adenosine (8-Cl-ADO) are known inhibitors of cancer cell proliferation; however, their mechanism of action is controversial. We have investigated the antiproliferative effects of 8-Cl-cAMP and 8-CL-ADO on human thyroid cancer cells and determined PKA's involvement. EXPERIMENTAL DESIGN We employed proliferation and apoptosis assays and PKA activity and cell cycle analysis to understand the effect of 8-Cl-ADO and 8-Cl-cAMP on human thyroid cancer and HeLa cell lines. RESULTS 8-Cl-ADO inhibited proliferation of all cells, an effect that lasted for at least 4 d. Proliferation was also inhibited by 8-Cl-cAMP, but this inhibition was reduced by 3-isobutyl-1-methylxanthine; both drugs stimulated apoptosis, and 3-isobutyl-1-methylxanthine drastically reduced 8-Cl-cAMP-induced cell death. 8-Cl-ADO induced cell accumulation in G1/S or G2/M cell cycle phases and differentially altered PKA activity and subunit levels. PKA stimulation or inhibition and adenosine receptor agonists or antagonists did not significantly affect proliferation. CONCLUSIONS 8-Cl-ADO and 8-Cl-cAMP inhibit proliferation, induce cell cycle phase accumulation, and stimulate apoptosis in thyroid cancer cells. The effect of 8-Cl-cAMP is likely due to its metabolite 8-Cl-ADO, and PKA does not appear to have direct involvement in the inhibition of proliferation by 8-Cl-ADO. 8-Cl-ADO may be a useful therapeutic agent to be explored in aggressive thyroid cancer.
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Affiliation(s)
- Audrey J Robinson-White
- Section on Endocrinology and Genetics, Program on Developmental Endocrinology and Genetics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
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4
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Balakrishnan K, Stellrecht CM, Genini D, Ayres M, Wierda WG, Keating MJ, Leoni LM, Gandhi V. Cell death of bioenergetically compromised and transcriptionally challenged CLL lymphocytes by chlorinated ATP. Blood 2005; 105:4455-62. [PMID: 15718423 PMCID: PMC1895042 DOI: 10.1182/blood-2004-05-1699] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Myeloid cell leukemia-1 (MCL-1) acts as a key survival factor for chronic lymphocytic leukemia (CLL) cells. In addition, dissipation of cellular bioenergy may impose a lethal effect on these quiescent cells. Previously, in multiple myeloma cell lines we demonstrated that halogenated adenosine (8-Cl-Ado) was phosphorylated to triphosphate (8-Cl-adenosine triphosphate [ATP]), which preferentially incorporated into mRNA and inhibited RNA synthesis by premature transcription termination. Furthermore, 8-Cl-ATP accumulation was associated with a decline in cellular bioenergy. Based on these actions, we hypothesized that 8-Cl-Ado would be ideal to target CLL lymphocytes. In the present study we demonstrate that leukemic lymphocytes incubated with 8-Cl-Ado display time- and dose-dependent increase in the accumulation of 8-Cl-ATP, with a parallel depletion of the endogenous ATP pool. Inhibition of global RNA synthesis resulted in a significant decline in the expression of transcripts with a short half-life such as MCL1. Consistent to this, protein expression of MCL-1 but not B-cell lymphoma-2 (BCL-2) was decreased. Furthermore, 8-Cl-ATP induced programmed cell death, as suggested by caspases activation, cleavage of caspase 3, and PARP (poly-adenosine diphosphate [ADP]-ribose polymerase), and increased DNA fragmentation. In conclusion, 8-Cl-Ado induces apoptosis in CLL lymphocytes by targeting cellular bioenergy as well as RNA transcription and translation of key survival genes such as MCL1.
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MESH Headings
- Adenosine Triphosphate/analogs & derivatives
- Adenosine Triphosphate/metabolism
- Adenosine Triphosphate/pharmacokinetics
- Adenosine Triphosphate/pharmacology
- Apoptosis/drug effects
- Cells, Cultured
- Dose-Response Relationship, Drug
- Energy Metabolism/drug effects
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Myeloid Cell Leukemia Sequence 1 Protein
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Proto-Oncogene Proteins c-bcl-2/biosynthesis
- Proto-Oncogene Proteins c-bcl-2/genetics
- RNA, Messenger/biosynthesis
- Transcription, Genetic/drug effects
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Affiliation(s)
- Kumudha Balakrishnan
- Department of Experimental Therapeutics, Unit 71, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
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Schwede F, Maronde E, Genieser H, Jastorff B. Cyclic nucleotide analogs as biochemical tools and prospective drugs. Pharmacol Ther 2000; 87:199-226. [PMID: 11008001 DOI: 10.1016/s0163-7258(00)00051-6] [Citation(s) in RCA: 187] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Cyclic AMP (cAMP) and cyclic GMP (cGMP) are key second messengers involved in a multitude of cellular events. From the wealth of synthetic analogs of cAMP and cGMP, only a few have been explored with regard to their therapeutic potential. Some of the first-generation cyclic nucleotide analogs were promising enough to be tested as drugs, for instance N(6),O(2)'-dibutyryl-cAMP and 8-chloro-cAMP (currently in clinical Phase II trials as an anticancer agent). Moreover, 8-bromo and dibutyryl analogs of cAMP and cGMP have become standard tools for investigations of biochemical and physiological signal transduction pathways. The discovery of the Rp-diastereomers of adenosine 3',5'-cyclic monophosphorothioate and guanosine 3',5'-cyclic monophosphorothioate as competitive inhibitors of cAMP- and cGMP-dependent protein kinases, as well as subsequent development of related analogs, has proven very useful for studying the molecular basis of signal transduction. These analogs exhibit a higher membrane permeability, increased resistance against degradation, and improved target specificity. Furthermore, better understanding of signaling pathways and ligand/protein interactions has led to new therapeutic strategies. For instance, Rp-8-bromo-adenosine 3',5'-cyclic monophosphorothioate is employed against diseases of the immune system. This review will focus mainly on recent developments in cyclic nucleotide-related biochemical and pharmacological research, but also highlights some historical findings in the field.
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Affiliation(s)
- F Schwede
- Center for Environmental Research and Environmental Technology, Department of Bioorganic Chemistry, University of Bremen, Leobener Strasse, D-28359, Bremen, Germany
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Lesiak KB, Uznanski B, Torrence PF. The solid-phase synthesis of 2'-5'-linked oligoriboadenylates containing 8-bromoadenine. Appl Biochem Biotechnol 1997; 67:33-44. [PMID: 9382489 DOI: 10.1007/bf02787839] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To increase the accessibility of 8-bromo-2',5'-oligoadenylates, we developed a synthesis of 2'-5'-linked oligoriboadenylates containing varying numbers of 8-bromoadenosine residues based on the use of a CPG-LCA solid support and the phosphoramidite approach. Although N6-benzoyl protection was satisfactory for incorporation of nonmodified adenine residues into 2',5'-oligonucleotides, the effective incorporation of 8-bromoadenine into such 2',5'-linked oligomers required use of a non acyl protecting group. Amidine protection of the purine exocyclic amino function proved compatible with all aspects of the phophoramidite approach and with the hydroxyl protection groups employed.
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Affiliation(s)
- K B Lesiak
- Section on Biomedical Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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7
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Langeveld CH, Jongenelen CA, Theeuwes JW, Baak JP, Heimans JJ, Stoof JC, Peters GJ. The antiproliferative effect of 8-chloro-adenosine, an active metabolite of 8-chloro-cyclic adenosine monophosphate, and disturbances in nucleic acid synthesis and cell cycle kinetics. Biochem Pharmacol 1997; 53:141-8. [PMID: 9037246 DOI: 10.1016/s0006-2952(96)00593-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
8-Chloro-adenosine, the dephosphorylated metabolite of the antineoplastic agent 8-chloro-cyclic AMP, has been proposed to act on the regulatory subunits of cyclic AMP-dependent protein kinase. 8-Chloro-adenosine has a growth-inhibitory effect, the mechanism of which is unclear. We investigated the effects of 8-chloro-cyclic AMP and 8-chloro-adenosine on nucleic acid synthesis and cell cycle kinetics in two human glioma cell lines. These effects were compared to those of the cyclic AMP analogue 8-(4-chlorophenyl)-thio-cyclic AMP (8-CPTcAMP), which is less susceptible to dephosphorylation. Whereas 8-CPTcAMP almost completely inhibited RNA and DNA synthesis, both 8-chloro-adenosine and 8-chloro-cyclic AMP only partly inhibited synthesis of RNA and DNA at growth-inhibitory concentrations, as demonstrated by using [5-1H] uridine and [14C]thymidine incorporation. Therefore, the growth-inhibitory effect of 8-chloro-cyclic AMP is not (or not completely) due to activation of cyclic AMP-dependent protein kinase nor to the inhibition of nucleic acid synthesis. Flow cytometric analysis revealed that 8-chloro-cyclic AMP and 8-chloro-adenosine probably block cell cycle progression at the G2M phase. The effects of 8-chloro-cyclic AMP on nucleic acid synthesis and cell cycle progression were largely prevented by adenosine deaminase, which inactivates 8-chloro-adenosine. This indicates that the effects of 8-chloro-cyclic AMP were at least in part due to its metabolite 8-chloro-adenosine. Incorporation of 8-chloro-adenosine into RNA and DNA might contribute to the disturbance of the cell cycle kinetics and growth-inhibitory effect of 8-chloro-adenosine.
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Affiliation(s)
- C H Langeveld
- Department of Neurology, Graduate School of Neurosciences Amsterdam, Vrije Universiteit, The Netherlands
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8
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Sandnes D, Jacobsen FW, Refsnes M, Christoffersen T. 8-bromo-cAMP and 8-CPT-cAMP increase the density of beta-adrenoceptors in hepatocytes by a mechanism not mimicking the effect of cAMP. PHARMACOLOGY & TOXICOLOGY 1996; 79:15-22. [PMID: 8841091 DOI: 10.1111/j.1600-0773.1996.tb00235.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Addition of 8-bromo-adenosine 3',5'-cyclic monophosphate (8-bromo-cAMP) or 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (8-CPT-cAMP) to hepatocytes at the time of plating enhanced the acquisition of beta-adrenoceptors that occurs spontaneously upon culturing as primary monolayers. This effect was partially suppressed by the phosphodiesterase inhibitor isobutyl methylxanthine, and was mimicked by 8-bromo-AMP, 8-bromo-adenosine, and the adenosine kinase inhibitor 5'-amino-5'-deoxyadenosine. Agents that elevated the intracellular level of cAMP, such as glucagon and forskolin, and Sp-8-bromo-adenosine 3',5'-monophosphorothioate (Sp-8-bromo-cAMPS), a cAMP analogue that is resistant towards metabolic breakdown, did not significantly enhance beta-adrenoceptor expression when used alone, but glucagon enhanced the effect of 8-bromo-adenosine. 8-bromo-cAMP and 8-bromo-adenosine decreased cellular ATP-levels. These observations suggest that the enhanced beta-adrenoceptor acquisition was mediated mainly through the action of metabolites of 8-bromo-cAMP and 8-CPT-cAMP, although there may be a cAMP-mediated component in the effect. Several mechanisms, including depletion of ATP, are probably involved, and might affect beta-adrenoceptor degradation.
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Affiliation(s)
- D Sandnes
- Department of Pharmacology, Faculty of Medicine, University of Oslo, Norway
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9
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Arnér ES. On the phosphorylation of 2-chlorodeoxyadenosine (CdA) and its correlation with clinical response in leukemia treatment. Leuk Lymphoma 1996; 21:225-31. [PMID: 8726403 DOI: 10.3109/10428199209067604] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The nucleoside analog 2-chlorodeoxyadenosine (CdA, Cladribine) is a chemotherapeutic agent for treatment of leukemias and lymphomas, most successfully used in hairy cell leukemia and B-cell chronic lymphocytic leukemia. CdA is phosphorylated intracellularly to its monophosphate derivative by the enzymes deoxycytidine kinase and deoxyguanosine kinase. Cell lines deficient in deoxycytidine kinase were shown to be resistant to CdA and a high deoxycytidine kinase level in combination with low 5'-nucleotidase has been proposed to partly explain the selectivity in CdA toxicity for lymphoid cells. In this report biochemical properties in CdA phosphorylation mediated by deoxycytidine kinase and deoxyguanosine kinase are reviewed and discussed in relation to the further metabolism of CdA 5'-monophosphate, the different possible mechanisms of action and the correlation with clinical response. It is concluded that much is known about the metabolism and mechanisms of action of CdA, but that the remarkable therapeutic effect in hairy cell leukemia has yet to be explicitly explained.
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Affiliation(s)
- E S Arnér
- Medical Nobel Institute for Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
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10
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Cummings J, Langdon SP, Ritchie AA, Burns DJ, Mackay J, Stockman P, Leonard RC, Miller WR. Pharmacokinetics, metabolism and tumour disposition of 8-chloroadenosine 3',5'-monophosphate in breast cancer patients and xenograft bearing mice. Ann Oncol 1996; 7:291-6. [PMID: 8740794 DOI: 10.1093/oxfordjournals.annonc.a010574] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND 8-Chloroadenosine 3',5'-monophosphate (8-Cl-cAMP) is undergoing phase I clinical trials as an anticancer drug. However, there is debate as to whether it is a prodrug for its 8-Cl-adenosine metabolite. DESIGN Pharmacokinetics, metabolism and tumour disposition studies have been performed in 7 breast cancer patients receiving continuous infusion (28 day) 8-Cl-cAMP (0.54 or 1.08 mg/kg/day) and tumour biopsies were obtained before and on the last day of infusion. Parallel studies were performed in nude mice bearing the HT29 human colon cancer xenograft after continuous infusion (7 day) of active drug doses (50 or 100 mg/kg/day). RESULTS Steady state plasma levels (Css) of 8-Cl-cAMP in patients ranged from 0.15-0.72 microM but 8-Cl-adenosine was not detected in plasma. In contrast, 8-Cl-cAMP was not detectable in 3 tumour biopsies but 8-Cl-adenosine was present in 2 samples at high concentrations (1.33 and 2.02 microM). In mice, Css of 8-Cl-cAMP ranged from 3.2-4.6 microM and 8-Cl adenosine was present in plasma only at the higher dose (100 mg/kg/day, peak concentration of 2.3 microM). In the HT29 xenograft, 8-Cl-cAMP levels were considerably lower than in plasma (0.37-1.22 microM) while 8-Cl-adenosine was present at 5.3-21.0 microM and 8-Cl-AMP was found at 11.3-35.7 microM. CONCLUSIONS The fate of 8-Cl-cAMP in human tumours is characterised by extensive metabolism to products which are not generally observed in plasma. These data raise the possibility that 8-Cl-cAMP is a prodrug for a product of its metabolism in human tumours.
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Affiliation(s)
- J Cummings
- Imperial Cancer Research Fund, Western General Hospital, Edinburgh, U.K
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11
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Romanová D, Novotný L. Chromatographic properties of cytosine, cytidine and their synthetic analogues. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1996; 675:9-15. [PMID: 8634774 DOI: 10.1016/0378-4347(95)00334-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A direct reversed-phase high-performance liquid chromatographic (RP-HPLC) assay was used for the study of the effects of methanol concentration, pH, flow-rate of the mobile phase and column temperature on the retention of the natural nuclei acid components cytosine and cytidine and their synthetic 1-beta-D-arabinofuranosyl, 5-aza and 6-aza analogues. The pKa values were also determined. The greatest changes were observed with changes in pH. The relationship between the capacity factors and the hydrophobicity of the compounds studied was also investigated.
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Affiliation(s)
- D Romanová
- Department of Experimental Therapy, Slovak Academy of Sciences, Bratislava, Slovak Republic
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12
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Spasokoukotskaja T, Arnér ES, Brosjö O, Gunvén P, Juliusson G, Liliemark J, Eriksson S. Expression of deoxycytidine kinase and phosphorylation of 2-chlorodeoxyadenosine in human normal and tumour cells and tissues. Eur J Cancer 1995; 31A:202-8. [PMID: 7718326 DOI: 10.1016/0959-8049(94)00435-8] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Deoxycytidine kinase (dCK) activates several clinically important drugs, including the recently developed antileukaemic compound 2-chlorodeoxyadenosine (CdA). The distribution of dCK in cells and tissues has previously been determined by activity measurements, which may be unreliable because of the presence of other enzymes with overlapping substrate specificities. Therefore we have measured dCK polypeptide levels in extracts of normal and malignant human peripheral blood mononuclear cells, gastrointestinal tissues and sarcomas, using a specific immunoblotting technique, as well as the phosphorylation of CdA in the same extracts. High levels of dCK were found in all major subpopulations of normal mononuclear leucocytes (120 +/- 19 ng dCK/mg protein) and in B-cell chronic lymphocytic leukaemia (81 +/- 30 ng/mg, n = 23). Hairy-cell leukaemia contained lower levels (28 +/- 23 ng/mg, n = 7), as did three samples of T-cell chronic lymphocytic leukaemia (18 +/- 14 ng/mg). Phytohaemagglutinin stimulation of normal lymphocytes did not lead to any substantial increase in either dCK activity or protein expression (less than 2.5-fold). The human CEM wt T-lymphoblastoid cell line contained 56 +/- 1 ng/dCK/mg protein, while in the CEM ddC50 and AraC8D mutants that lack dCK activity, no dCK polypeptide could be detected. In colon adenocarcinomas, the dCK content was significantly higher (20 +/- 9 ng/mg, n = 20) than in normal colon mucosa (8 +/- 3.5 ng/mg, n = 19, P < 0.05). A similar pattern of dCK expression was found in gastric adenocarcinomas (21 +/- 13 ng/mg, n = 5) and normal stomach mucosa (6 +/- 5 ng/mg, n = 5, P < 0.15). One leiomyosarcoma and one extra-skeletal osteosarcoma showed dCK levels comparable with those found in normal lymphocytes (84 +/- 6 and 109 +/- 4 ng/mg, respectively), while other sarcoma samples contained lower levels, comparable to the gastrointestinal adenocarcinomas (20 +/- 7 ng/mg, n = 12). Thus, dCK is expressed constitutively and predominantly in lymphoid cells, but it is also found in solid non-lymphoid tissues, with increased levels in malignant cells. The phosphorylation of CdA in crude extracts showed a close correlation to the dCK polypeptide level.
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Affiliation(s)
- T Spasokoukotskaja
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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13
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Cummings J, Fielding H, Miller WR. Pharmaceutical analysis of 8-chloroadenosine 3',5'-monophosphate. J Pharm Biomed Anal 1994; 12:1289-94. [PMID: 7841225 DOI: 10.1016/0731-7085(94)00051-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
8-Chloroadenosine 3',5'-monophosphate (8-Cl-cAMP) has recently entered clinical trials as a new anticancer drug. 8-Cl-cAMP can undergo metabolism/degradation to nucleotides (8-Cl-AMP; 8-Cl-IMP), nucleosides (8-Cl-adenosine; 8-Cl-inosine) and bases (8-Cl-adenine; 8-Cl-xanthine and 8-Cl-hypoxanthine). A reversed-phase, gradient elution high-performance liquid chromatographic method is described which can resolve all the above from their non-chlorinated naturally occurring counterparts and 8-Bromo-cAMP. The assay was then utilized to perform pharmaceutical evaluations on the 8-Cl-cAMP formulation. Sterilization by filtration (0.22 micron pore size) resulted in no loss of material. Stability studies carried out in the cartridges used to continuously infuse (for 7 days) the drug to patients showed no significant degradation over 17 days. Purity determinations revealed the presence of up to nine impurities (related to adenine) and yielded a purity figure of 95.9-99.3% with considerable batch to batch variation.
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Affiliation(s)
- J Cummings
- Imperial Cancer Research Fund, Medical Oncology Unit, Western General Hospital, Edinburgh, UK
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14
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Reichelová V, Albertioni F, Liliemark J. Hydrophobicity parameters of 2-chloro-2′-deoxyadenosine and some related analogues and retention in reversed-phase liquid chromatography. J Chromatogr A 1994. [DOI: 10.1016/0021-9673(94)89049-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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15
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Arnér ES, Spasokoukotskaja T, Eriksson S. Selective assays for thymidine kinase 1 and 2 and deoxycytidine kinase and their activities in extracts from human cells and tissues. Biochem Biophys Res Commun 1992; 188:712-8. [PMID: 1359886 DOI: 10.1016/0006-291x(92)91114-6] [Citation(s) in RCA: 123] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Human cells salvage pyrimidine deoxyribonucleosides via 5'-phosphorylation which is also the route of activation of many chemotherapeutically used nucleoside analogs. Key enzymes in this metabolism are the cytosolic thymidine kinase (TK1), the mitochondrial thymidine kinase (TK2) and the cytosolic deoxycytidine kinase (dCK). These enzymes are expressed differently in different tissues and cell cycle phases, and they display overlapping substrate specificities. Thymidine is phosphorylated by both thymidine kinases, and deoxycytidine is phosphorylated by both dCK and TK2. The enzymes also phosphorylate nucleoside analogs with very different efficiencies. Here we present specific radiochemical assays for the three kinase activities utilizing analogs as substrates that are by more than 90 percent phosphorylated solely by one of the kinases; i.e. 3'-azido-2',3'-dideoxythymidine (AZT) as substrate for TK1, 1-beta-D-arabinofuranosylthymidine (AraT) for TK2 and 2-chlorodeoxyadenosine (CdA) for dCK. We determined the fraction of the total deoxycytidine and thymidine phosphorylating activity that was provided by each of the three enzymes in different human cells and tissues, such as resting and proliferating lymphocytes, lymphocytic cells of leukemia patients (chronic lymphocytic, chronic myeloic and hairy cell leukemia), muscle, brain and gastrointestinal tissue. The detailed knowledge of the pyrimidine deoxyribonucleoside kinase activities and substrate specificities are of importance for studies on chemotherapeutically active nucleoside analogs, and the assays and data presented here should be valuable tools in that research.
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Affiliation(s)
- E S Arnér
- Department of Biochemistry I, Karolinska Institutet, Stockholm, Sweden
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16
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Kemena A, Fernandez M, Bauman J, Keating M, Plunkett W. A sensitive fluorescence assay for quantitation of fludarabine and metabolites in biological fluids. Clin Chim Acta 1991; 200:95-106. [PMID: 1723357 DOI: 10.1016/0009-8981(91)90081-m] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Rapid and quantitative dephosphorylation of the new anticancer nucleotide analogue fludarabine phosphate to its nucleoside 9-beta-D-arabinofuranosyl-2-fluoroadenine (F-ara-A) renders this metabolite the target for pharmacologic investigations. At clinically effective doses of fludarabine phosphate (18-30 mg/m2 per day) comprehensive pharmacokinetic analysis of F-ara-A has been limited by the sensitivity of UV based HPLC assays. To address this problem we developed a sensitive test based on the condensation of F-ara-A with chloroacetaldehyde to form the fluorescent derivative, arabinosyl-1,N6-etheno-isoguanine. Combined with a solid-phase extraction step prior to derivatization and separation of the reaction products by reverse-phase HPLC, this assay had a quantitation limit of 2 pmol F-ara-A per ml plasma. Slightly modified, the system was also applicable to urine specimens, with a quantitation limit of 1 nmol F-ara-A per ml urine.
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Affiliation(s)
- A Kemena
- University of Texas M.D. Anderson Cancer Center, Houston 77030
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17
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Abstract
Recent investigations have identified many new purine nucleoside analogs that act as antimetabolites. This article focuses on the metabolism and mechanisms of action of tiazofurin, 3-deazaguanosine, neplanocin A, arabinosyladenine in combination with inhibitors of adenosine deaminase, arabinosyl-2-fluoroadenine, and 2-chloro-2'-deoxyadenosine, drugs that are either currently being evaluated in clinical trials or are close to that stage. The diverse metabolic requirements for activation, unique mechanisms of action, and differential biological activities of these compounds are characterized and evaluated for prospective therapeutic application.
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Affiliation(s)
- W Plunkett
- Department of Medical Oncology, University of Texas M.D. Anderson Cancer Center, Houston 77030
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18
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Nair V, Purdy DF. Synthetic approaches to new doubly modified nucleosides: Congeners of cordycepin and related 2′-deoxyadenosine. Tetrahedron 1991. [DOI: 10.1016/s0040-4020(01)90496-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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