1
|
Structural basis for inhibition of mycobacterial and human adenosine kinase by 7-substituted 7-(Het)aryl-7-deazaadenine ribonucleosides. J Med Chem 2014; 57:8268-79. [PMID: 25259627 DOI: 10.1021/jm500497v] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Adenosine kinase (ADK) from Mycobacterium tuberculosis (Mtb) was selected as a target for design of antimycobacterial nucleosides. Screening of 7-(het)aryl-7-deazaadenine ribonucleosides with Mtb and human (h) ADKs and testing with wild-type and drug-resistant Mtb strains identified specific inhibitors of Mtb ADK with micromolar antimycobacterial activity and low cytotoxicity. X-ray structures of complexes of Mtb and hADKs with 7-ethynyl-7-deazaadenosine showed differences in inhibitor interactions in the adenosine binding sites. 1D (1)H STD NMR experiments revealed that these inhibitors are readily accommodated into the ATP and adenosine binding sites of Mtb ADK, whereas they bind preferentially into the adenosine site of hADK. Occupation of the Mtb ADK ATP site with inhibitors and formation of catalytically less competent semiopen conformation of MtbADK after inhibitor binding in the adenosine site explain the lack of phosphorylation of 7-substituted-7-deazaadenosines. Semiempirical quantum mechanical analysis confirmed different affinity of nucleosides for the Mtb ADK adenosine and ATP sites.
Collapse
|
2
|
9-Norbornyl-6-chloropurine is a novel antileukemic compound interacting with cellular GSH. Anticancer Res 2013; 33:3163-3168. [PMID: 23898074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
AIM 6-Chloropurines substituted at position 9 with bicyclic skeletons represent promising chemotherapeutic agents. We explored the metabolism and membrane transport of 9-norbornyl-6-chloropurine (NCP) aiming to understand its mechanism of action. MATERIALS AND METHODS The metabolism of NCP was studied in vitro in whole cells (CCRF-CEM), cellular extracts, subcellular fractions and purified enzymes. Transport experiments were conducted in Caco-2 cell monolayers. RESULTS Three metabolites were identified, a glutathione conjugate (NCP-GS), NCP-cysteinylglycine and NCP-cysteine. Both glutathione-S-transferase inhibition and glutathione (GSH) depletion prevented metabolite formation and increased the cytotoxicity of NCP. Transepithelial transport (Caco-2) indicated good permeability, with Papp (12.6±0.3) ×10(-5) cm/s. Importantly, the drug induced glutathione depletion in treated cells and affected the activity of several GSH-dependent enzymes. CONCLUSION The novel nucleoside analog NCP represents a promising orally available antileukemic agent, acting through lowering of GSH levels in tumor cells.
Collapse
|
3
|
Mutations in adenosine deaminase-like (ADAL) protein confer resistance to the antiproliferative agents N6-cyclopropyl-PMEDAP and GS-9219. Anticancer Res 2013; 33:1899-1912. [PMID: 23645737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
BACKGROUND/AIM GS 9219 is a double prodrug of antiproliferative nucleotide analog 9-(2-Phosphonylmethoxyethyl)guanine (PMEG), with potent in vivo efficacy against various hematological malignancies. This study investigates the role of adenosine deaminase-like (ADAL) protein in the intracellular activation of GS-9219. MATERIALS AND METHODS A cell line resistant to 9-(2-Phosphonylmethoxyethyl)-N(6)-cyclopropyl-2,6-diaminopurine (cPrPMEDAP), an intermediate metabolite of GS-9219, was generated and characterized. RESULTS The resistant cell line was cross-resistant to cPrPMEDAP and GS-9219, due to a defect in the deamination of cPrPMEDAP to PMEG. Mutations in the ADAL gene (H286R and S180N) were identified in the resistant cells that adversely-affected its enzymatic activity. Introduction of the wild-type ADAL gene re-sensitized resistant cells to both cPrPMEDAP and GS-9219. CONCLUSION The ADAL protein plays an essential role in the intracellular activation of GS-9219 by catalyzing the deamination of cPrPMEDAP metabolite to PMEG. Mutations affecting the activity of ADAL confer resistance to both GS-9219 and its metabolite cPrPMEDAP.
Collapse
|
4
|
6-Alkyl-, 6-aryl- or 6-hetaryl-7-deazapurine ribonucleosides as inhibitors of human or MTB adenosine kinase and potential antimycobacterial agents. MEDCHEMCOMM 2013. [DOI: 10.1039/c3md00232b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
5
|
Sphingosine and clavaminol H derivatives bearing fluorinated chains and their cytotoxic activity. J Fluor Chem 2012. [DOI: 10.1016/j.jfluchem.2012.06.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
6
|
Sugar-modified derivatives of cytostatic 7-(het)aryl-7-deazaadenosines: 2'-C-methylribonucleosides, 2'-deoxy-2'-fluoroarabinonucleosides, arabinonucleosides and 2'-deoxyribonucleosides. Bioorg Med Chem 2012; 20:5202-14. [PMID: 22877872 DOI: 10.1016/j.bmc.2012.07.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 07/02/2012] [Accepted: 07/02/2012] [Indexed: 01/20/2023]
Abstract
A series of novel sugar-modified derivatives of cytostatic 7-hetaryl-7-deazaadenosines (2'-C-methylribonucleosides, 2'-deoxy-2'-fluoroarabinonucleosides, arabinonucleosides and 2'-deoxyribonucleosides) was prepared and screened for biological activity. The synthesis consisted of preparation of the corresponding sugar-modified 7-iodo-7-deazaadenine nucleosides and their aqueous-phase Suzuki-Miyaura cross-coupling reactions with (het)arylboronic acids or Stille couplings with hetarylstannanes in DMF. The synthesis of 7-iodo-7-deazaadenine nucleosides was based on a glycosidation of 6-chloro-7-iodo-7-deazapurine with a suitable sugar synthon or on an interconversion of 2'-OH stereocenter (for arabinonucleosides). Several examples of 2'-C-Me-ribonucleosides showed moderate anti-HCV activities in a replicon assay accompanied by cytotoxicity. Several 7-hetaryl-7-deazaadenine fluoroarabino- and arabinonucleosides exerted moderate micromolar cytostatic effects. The most active was 7-ethynyl-7-deazaadenine fluoroarabinonucleoside which showed submicromolar antiproliferative activity. However, all the sugar-modified derivatives were less active than the parent ribonucleosides.
Collapse
|
7
|
Involvement of MAP kinases in the cytotoxicity of acyclic nucleoside phosphonates. Anticancer Res 2012; 32:497-501. [PMID: 22287737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND 9-[2-(phosphonomethoxy)ethyl] guanine (PMEG) is a nucleotide analogue with anticancer activity. Here we investigate the role of ERK, p38, JNK and AKT kinases in PMEG-induced apoptosis. MATERIALS AND METHODS CCRF-CEM and HL-60 leukemia cells were used to assess MAPK mRNA and protein expression in PMEG-treated cells. MAPK activation was measured using phospho-specific antibodies. Apoptosis was evaluated by caspase-3 and PARP cleavage. RESULTS Up-regulation of p38β, γ and δ mRNA were observed following PMEG treatment of CCRF-CEM cells, however, the total protein expression remained unchanged. Neither PMEG nor its analogue 9-[2-(phosphonomethoxy) ethyl]-2,6-diaminopurine (PMEDAP) induced p38 kinase phosphorylation in CCRF-CEM cells, whereas increased p38 phosphorylation was observed in HL-60 cells. The ERK pathway was also activated by these compounds. Pretreatment of the cells with the p38 inhibitor SB203580 diminished drug-induced apoptosis whereas inhibition of ERK, JNK or AKT pathways did not. [corrected]. CONCLUSION PMEG- and PMEDAP-induced. [corrected].
Collapse
|
8
|
Antiviral activity of tenofovir against Cauliflower mosaic virus and its metabolism in Brassica pekinensis plants. Antiviral Res 2011; 92:378-81. [DOI: 10.1016/j.antiviral.2011.08.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 07/26/2011] [Accepted: 08/16/2011] [Indexed: 11/28/2022]
|
9
|
Synthesis and biological activity of desmethoxy analogues of coruscanone A. Bioorg Med Chem Lett 2011; 21:6062-6. [DOI: 10.1016/j.bmcl.2011.08.059] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 08/10/2011] [Accepted: 08/11/2011] [Indexed: 11/27/2022]
|
10
|
A novel and efficient one-pot synthesis of symmetrical diamide (bis-amidate) prodrugs of acyclic nucleoside phosphonates and evaluation of their biological activities. Eur J Med Chem 2011; 46:3748-54. [DOI: 10.1016/j.ejmech.2011.05.040] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Revised: 05/12/2011] [Accepted: 05/14/2011] [Indexed: 10/18/2022]
|
11
|
Efficient one-pot synthesis of polysubstituted 6-[(1H-1,2,3-triazol-1-yl)methyl]uracils through the “click” protocol. ACTA ACUST UNITED AC 2011. [DOI: 10.1135/cccc2011074] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The preparation of several triazolo acyclic nucleosides and triazolo acyclic nucleoside phosphonates is described. The synthetic methodology has been developed as an efficient one-pot Cu(I)-catalyzed azide alkyne Huisgen “click” cycloaddition. A novel Cu(I)-catalyzed decarboxylation reaction of 1-substituted 1H-1,2,3-triazole-4-carboxylic acids at room temperature was observed and used for the preparation of 1-substituted 1H-1,2,3-triazoles. As congeners of TPI (Taiho pharmaceutical inhibitor), the prepared compounds were screened as potential inhibitors of human thymidine phosphorylase, but no inhibitory activity was observed.
Collapse
|
12
|
Modulation of cell cycle progression and of antibody production in mouse hybridomas by a nucleotide analogue. Cytotechnology 2011; 28:65-72. [PMID: 19003408 DOI: 10.1023/a:1008017328061] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The nucleotide analogue 9-[2-(phosphonomethoxy)ethyl]guanine (PMEG) has been identified as a powerful antiproliferative substance when acting on hybridoma cells. In the range of 10 nM to 100 nM concentrations this agent reduces cell growth rate, while its apoptosis-inducing activity is marginal. Marked induction of apoptosis can be observed at micromolar and higher order concentrations. In PMEG-supplemented media the cell cycle progression is perturbed, the flow-cytometric DNA profile shows a higher proportion of cells in the S and G2/M phases of the cell cycle. Concomitantly with the reduction of the growth rate, the specific monoclonal antibody production rate may rise by 20-27%. Addition of PMEG at the end of the exponential phase of a batch culture results in an enhancement of the final monoclonal antibody concentration.
Collapse
|
13
|
Synthesis and Significant Cytostatic Activity of 7-Hetaryl-7-deazaadenosines. J Med Chem 2011; 54:5498-507. [DOI: 10.1021/jm2005173] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
14
|
Point mutations in human guanylate kinase account for acquired resistance to anticancer nucleotide analogue PMEG. Biochem Pharmacol 2011; 82:131-8. [DOI: 10.1016/j.bcp.2011.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 04/01/2011] [Accepted: 04/04/2011] [Indexed: 01/23/2023]
|
15
|
2´-deoxy-5,6-dihydro-5-azacytidine - a less toxic alternative of 2´-deoxy-5-azacytidine: a comparative study of hypomethylating potential. Epigenetics 2011; 6:769-76. [PMID: 21566456 DOI: 10.4161/epi.6.6.16215] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Restoration of transcriptionally silenced genes by means of methyltransferases inhibitors plays a crucial role in the current therapy of myelodysplastic syndromes and certain types of leukemias. A comparative study of hypomethylating activities of a series of 5-azacytidine nucleosides: 5-azacytidine (AC), 2'-deoxy-5-azacytidine (DAC) and its α-anomer (α-DAC), 5,6-dihydro-5-azacytidine (DHAC), 2'-deoxy-5,6-dihydro-5-azacytidine (DHDAC, KP-1212) and its α-anomer (α-DHDAC), and of a 2-pyrimidone ribonucleoside (zebularine) was conducted. Methylation-specific PCR was employed to detect the efficiency of individual agents on cyclin-dependent kinase inhibitor 2B and thrombospondin-1 hypermethylated gene loci. Overall changes in DNA methylation level were quantified by direct estimation of 5-methyl-2'-deoxycytidine-5'-monophosphate by HPLC using digested genomic DNA. Flow cytometric analysis of cell cycle progression and apoptotic markers was used to determine cytotoxicity of the compounds. mRNA expression was measured using qRT-PCR. 2'-deoxy-5,6-dihydro-5-azacytidine was found to be less cytotoxic and more stable than 2'-deoxy-5-azacytidine at the doses that induce comparable DNA hypomethylation and gene reactivation. This makes it a valuable tool for epigenetic research and worth further investigations to elucidate its possible therapeutic potential.
Collapse
|
16
|
Synthesis and antiviral activity of N9-[3-fluoro-2-(phosphonomethoxy)propyl] analogues derived from N6-substituted adenines and 2,6-diaminopurines. Bioorg Med Chem 2011; 19:2114-24. [PMID: 21429755 DOI: 10.1016/j.bmc.2011.02.050] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 02/23/2011] [Accepted: 02/28/2011] [Indexed: 11/29/2022]
Abstract
An efficient method for the synthesis of N(9)-[3-fluoro-2-(phosphonomethoxy)propyl] (FPMP) derivatives of purine bases has been developed. Both (R)- and (S)-enantiomers of the N(6)-substituted FPMP derivatives of adenine and 2,6-diaminopurine were prepared and their anti-human immunodeficiency virus (HIV) and anti-Moloney murine sarcoma virus (MSV) activity was evaluated. Whereas none of the 6-substituted FPMPA derivatives showed any antiviral activity, several FPMPDAP derivatives had a moderate antiretroviral activity. Moreover, the data obtained from the study of the substrate activity of the active derivatives towards N(6)-methyl-AMP aminohydrolase support the notion that the studied N(6)-substituted FPMPDAP derivatives act as prodrugs of the antiretroviral FPMPG analogues.
Collapse
|
17
|
Inhibition of SAH-hydrolase activity during seed germination leads to deregulation of flowering genes and altered flower morphology in tobacco. Mol Genet Genomics 2011; 285:225-36. [PMID: 21274566 DOI: 10.1007/s00438-011-0601-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Accepted: 01/06/2011] [Indexed: 02/06/2023]
Abstract
Developmental processes are closely connected to certain states of epigenetic information which, among others, rely on methylation of chromatin. S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) are key cofactors of enzymes catalyzing DNA and histone methylation. To study the consequences of altered SAH/SAM levels on plant development we applied 9-(S)-(2,3-dihydroxypropyl)-adenine (DHPA), an inhibitor of SAH-hydrolase, on tobacco seeds during a short phase of germination period (6 days). The transient drug treatment induced: (1) dosage-dependent global DNA hypomethylation mitotically transmitted to adult plants; (2) pleiotropic developmental defects including decreased apical dominance, altered leaf and flower symmetry, flower whorl malformations and reduced fertility; (3) dramatic upregulation of floral organ identity genes NTDEF, NTGLO and NAG1 in leaves. We conclude that temporal SAH-hydrolase inhibition deregulated floral genes expression probably via chromatin methylation changes. The data further show that plants might be particularly sensitive to accurate setting of SAH/SAM levels during critical developmental periods.
Collapse
|
18
|
Phosphoramidate pronucleotides of cytostatic 6-aryl-7-deazapurine ribonucleosides. Bioorg Med Chem 2010; 19:229-42. [PMID: 21134754 DOI: 10.1016/j.bmc.2010.11.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 11/08/2010] [Accepted: 11/10/2010] [Indexed: 10/18/2022]
Abstract
A series of O-phenyl methyl-, ethyl- and benzylalanyl phosphoramidate pronucleotides derived from cytostatic 6-aryl-7-deazapurine ribonucleosides were prepared by the cross-coupling reactions of the 2',3'-isopropylidene protected 6-chloro-7-deazapurine ribonucleoside phosphoramidates with (het)arylboronic acids or -stannanes followed by deprotection. Most of the prepared prodrugs exerted in vitro cytostatic effects against both solid tumor and lymphoid cancer cells within low micromolar range of concentrations. These activities were in general weaker or comparable to the activities of the parent nucleosides. Additional testing of selected prodrugs suggests that the lack of activity improvement over parent nucleosides is not due to the lack of permeability or inefficient catabolism of alanyl-ester by intracellular hydrolases. More likely, active efflux of prodrugs may play a role in their weak cytotoxic activity.
Collapse
|
19
|
New in vitro method for evaluating antiviral activity of acyclic nucleoside phosphonates against plant viruses. Antiviral Res 2010; 88:296-303. [DOI: 10.1016/j.antiviral.2010.09.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 09/10/2010] [Accepted: 09/29/2010] [Indexed: 11/29/2022]
|
20
|
Inhibition of human purine nucleoside phosphorylase by tenofovir phosphate congeners. ACTA ACUST UNITED AC 2010. [DOI: 10.1135/cccc2010094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The structure-activity study on the phosphates of phosphonomethoxypropyl derivatives of purine bases interacting with human purine nucleoside phosphorylase has shown that the most efficient inhibitors of the enzyme are (R)- and (S)-PMPGp with Ki ~ 1.9 × 10–8 and/or 2.2 × 10–8 mol/l. The kinetic experiments have proven, with the exception of both enantiomers of PMP-8-BrDAPp, strictly competitive character of inhibition for all ANP monophosphates tested. Bromine derivatives exhibited uncompetitive and mixed type of inhibition as well. These results were confirmed by docking studies. The substitution of purine moiety with the bromine at the position 8 lead to an allosteric binding of these compounds toward the enzyme.
Collapse
|
21
|
CycloSal-phosphate pronucleotides of cytostatic 6-(Het)aryl-7-deazapurine ribonucleosides: Synthesis, cytostatic activity, and inhibition of adenosine kinases. ChemMedChem 2010; 5:1386-96. [PMID: 20533504 DOI: 10.1002/cmdc.201000192] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A series of cycloSal-phosphate prodrugs of a recently described new class of nucleoside cytostatics (6-hetaryl-7-deazapurine ribonucleosides) was prepared. The corresponding 2',3'-isopropylidene 6-chloro-7-deazapurine nucleosides were converted into 5-O'-cycloSal-phosphates. These underwent a series of Stille or Suzuki cross-couplings with diverse (het)arylstannanes or -boronic acids to yield the protected 6-(het)aryl-7-deazapurine pronucleotides that were subsequently deprotected to give 12 derivatives of free pronucleotides. The in vitro cytostatic effect of the pronucleotides was compared with parent nucleoside analogues. In most cases, the activity of the pronucleotide was similar to or somewhat lower than that of the corresponding parent nucleosides, with the exception of 7-fluoro pronucleotides 13 a, 13 b, and 13 d, which had exhibited GIC(50) values that were improved by one order of magnitude (to the low nanomolar range). The presence of a cycloSal-phosphate group also influenced selectivity toward various cell lines. Several pronucleotides were found which strongly inhibit human adenosine kinase but only weakly inhibit the MTB adenosine kinase.
Collapse
|
22
|
Role of caspases and CD95/Fas in the apoptotic effects of a nucleotide analog PMEG in CCRF-CEM cells. Anticancer Res 2010; 30:2791-2798. [PMID: 20683014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
BACKGROUND/AIM 9-[2-(phosphonomethoxy)ethyl] guanine (PMEG) is a guanine acyclic nucleotide analog whose targeted prodrugs are being investigated for chemotherapy of lymphomas. Its antiproliferative effects have been attributed to cell cycle arrest and induction of apoptosis, however, the underlying mechanisms remain poorly understood. The objective of this study was to determine the requirements for caspase and CD95/Fas activation in PMEG-induced apoptosis. Additionally, the influence of PMEG on cell cycle regulatory proteins was explored. MATERIALS AND METHODS CCRF-CEM cells were exposed to PMEG with/without caspase inhibitor or anti-Fas blocking antibody and assayed for phosphatidyl serine externalization, mitochondrial depolarization and the cleavage of procaspase 3 and the nuclear protein poly (ADP-ribose) polymerase (PARP). RESULTS Despite an observed increase of caspase 3, 8 and 9 proteolytic activity, neither pretreatment of the cells with cell-permeable caspase inhibitors nor blocking the death receptor with anti-Fas antibody did prevent apoptosis induced by PMEG. CONCLUSION PMEG-induced apoptosis is caspase- and CD95/Fas-independent.
Collapse
|
23
|
Antifungal 3,5-disubstituted furanones: From 5-acyloxymethyl to 5-alkylidene derivatives. Bioorg Med Chem 2010; 18:1988-2000. [DOI: 10.1016/j.bmc.2010.01.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Revised: 01/11/2010] [Accepted: 01/13/2010] [Indexed: 10/19/2022]
|
24
|
The acyclic 2,4-diaminopyrimidine nucleoside phosphonate acts as a purine mimetic in HIV-1 reverse transcriptase DNA polymerization. J Biol Chem 2010; 285:12101-8. [PMID: 20164190 DOI: 10.1074/jbc.m109.096529] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The acyclic pyrimidine nucleoside phosphonate (ANP) phosphonylmethoxyethoxydiaminopyrimidine (PMEO-DAPym) differs from other ANPs in that the aliphatic alkyloxy linker is bound to the C-6 of the 2,4-diaminopyrimidine base through an ether bond, instead of the traditional alkyl linkage to the N-1 or N-9 of the pyrimidine or purine base. In this study, we have analyzed the molecular interactions between PMEO-DAPym-diphosphate (PMEO-DAPym-pp) and the active sites of wild-type (WT) and drug-resistant HIV-1 reverse transcriptase (RT). Pre-steady-state kinetic analyses revealed that PMEO-DAPym-pp is a good substrate for WT HIV-1 RT: its catalytic efficiency of incorporation (k(pol)/K(d)) is only 2- to 3-fold less than that of the corresponding prototype purine nucleotide analogs PMEA-pp or (R)PMPA-pp. HIV-1 RT recognizes PMEO-DAPym-pp as a purine base instead of a pyrimidine base and incorporates it opposite to thymine (in DNA) or uracil (in RNA). Molecular modeling demonstrates that PMEO-DAPym-pp fits into the active site of HIV-1 RT without significant perturbation of key amino acid residues and mimics an open incomplete purine ring that allows the canonical Watson-Crick base pairing to be maintained. PMEO-DAPym-pp is incorporated more efficiently than (R)PMPA-pp by mutant K65R HIV-1 RT and is not as efficiently excised as (R)PMPA by HIV-1 RT containing thymidine analog mutations. Overall, the data revealed that PMEO- DAPym represents the prototype compound of a novel class of pyrimidine acyclic nucleoside phosphonates that are recognized as a purine nucleotide and should form the rational basis for the design and development of novel purine nucleo(s)(t)ide mimetics as potential antiviral or antimetabolic agents.
Collapse
|
25
|
Abstract
A series of novel 7-deazapurine ribonucleosides bearing an alkyl, aryl, or hetaryl group in position 6 and H, F, or Cl atom in position 7 has been prepared either by Pd-catalyzed cross-coupling reactions of the corresponding protected 6-chloro-(7-halogenated-)7-deazapurine ribonucleosides with alkyl- or (het)arylorganometallics followed by deprotection, or by single-step aqueous phase cross-coupling reactions of unprotected 6-chloro-(7-halogenated-)7-deazapurine ribonucleosides with (het)arylboronic acids. Significant cytostatic effect was detected with a substantial proportion of the prepared compounds. The most potent were 7-H or 7-F derivatives of 6-furyl- or 6-thienyl-7-deazapurines displaying cytostatic activity in multiple cancer cell lines with a geometric mean of 50% growth inhibition concentration ranging from 16 to 96 nM, a potency comparable to or better than that of the nucleoside analogue clofarabine. Intracellular phosphorylation to mono- and triphosphates and the inhibition of total RNA synthesis was demonstrated in preliminary study of metabolism and mechanism of action studies.
Collapse
|
26
|
|
27
|
Lasioglossins: three novel antimicrobial peptides from the venom of the eusocial bee Lasioglossum laticeps (Hymenoptera: Halictidae). Chembiochem 2009; 10:2089-99. [PMID: 19591185 DOI: 10.1002/cbic.200900133] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Three novel structurally related pentadecapeptides, named lasioglossins, were isolated from the venom of the eusocial bee Lasioglossum laticeps. Their primary sequences were established as H-Val-Asn-Trp-Lys-Lys-Val-Leu-Gly-Lys-Ile-Ile-Lys-Val-Ala-Lys-NH(2) (LL-I), H-Val-Asn-Trp-Lys-Lys-Ile-Leu-Gly-Lys-Ile-Ile-Lys-Val-Ala-Lys-NH(2) (LL-II) and H-Val-Asn-Trp-Lys-Lys-Ile-Leu-Gly-Lys-Ile-Ile-Lys-Val-Val-Lys-NH(2) (LL-III). These lasioglossins exhibited potent antimicrobial activity against both Gram-positive and Gram-negative bacteria, low haemolytic and mast cell degranulation activity, and a potency to kill various cancer cells in vitro. The lasioglossin CD spectra were measured in the presence of trifluoroethanol and sodium dodecyl sulfate solution and indicated a high degree of alpha-helical conformation. NMR spectroscopy, which was carried out in trifluoroethanol/water confirmed a curved alpha-helical conformation with a concave hydrophobic and convex hydrophilic side. To understand the role of this bend on biological activity, we studied lasioglossin analogues in which the Gly in the centre of the molecule was replaced by other amino acid residues (Ala, Lys, Pro). The importance of the N-terminal part of the molecule to the antimicrobial activity was revealed through truncation of five residues from both the N and C termini of the LL-III peptide. C-terminal deamidation of LL-III resulted in a drop in antimicrobial activity, but esterification of the C terminus had no effect. Molecular modelling of LL-III and the observed NOE contacts indicated the possible formation of a bifurcated H-bond between hydrogen from the Lys15 CONH peptide bond and one H of the C-terminal CONH(2) to the Ile11 oxygen atom. Such interactions cannot form with C-terminal esterification.
Collapse
|
28
|
Cytostatic tetrazole–butenolide conjugates: linking tetrazole and butenolide rings via stille coupling and biological activity of the target substances. ACTA ACUST UNITED AC 2009. [DOI: 10.1135/cccc2009040] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A series of tetrazoles linked to the butenolide core via benzene rings were prepared by the Stille coupling reaction of α-(tributylstannyl)butenolides and 5-(alkylsulfanyl)-1-(4-iodophenyl)tetrazoles, and the compounds were tested for antifungal and cytostatic activity. Interesting antifungal activities against the filamentous strain Absidia corymbifera, and cytostatic activities against leukemic cells HL-60 and CCRF-CEM were found. The cytostatic activity requires the presence of both the butenolide ring and the alkylsulfanyl group bound to tetrazole ring. In addition, the feasibility of Pd-coupling reactions with 5-iodotetrazoles was evaluated.
Collapse
|
29
|
In vivo modulation of angiogenic gene expression by acyclic nucleoside phosphonates PMEDAP and PMEG. Anticancer Res 2009; 29:1295-1302. [PMID: 19414378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Acyclic nucleoside phosphonates PMEDAP and PMEG modulate expression of selected proangiogenic genes in SD-lymphoma bearing rats. Antiangiogenic efficacy of PMEDAP is relatively weak and is manifested mainly by down-regulation of vascular endothelial growth factor (VEGF) and its receptor VEGFR detectable 24 hours after treatment. Compound PMEG (an active metabolite of the prodrug GS-9219) down-regulates selected proangiogenic genes EGF, FGF, PDGF, VEGF, EGFR, FGFR, PDGFR and VEGFR much more efficiently. Its antiangiogenic potency persists and is more intensive 48 hours after treatment. Findings show that in vivo antitumour efficacy of both antimitotic acyclic nucleoside phosphonates PMEDAP and PMEG consequently affect the angiogenesis in T-cell lymphoma.
Collapse
MESH Headings
- Adenine/analogs & derivatives
- Adenine/pharmacology
- Animals
- Epidermal Growth Factor/genetics
- Epidermal Growth Factor/metabolism
- ErbB Receptors/genetics
- ErbB Receptors/metabolism
- Fibroblast Growth Factor 1/genetics
- Fibroblast Growth Factor 1/metabolism
- Gene Expression Regulation, Neoplastic/drug effects
- Guanine/analogs & derivatives
- Guanine/pharmacology
- Lymphoma, T-Cell/genetics
- Lymphoma, T-Cell/metabolism
- Lymphoma, T-Cell/pathology
- Male
- Neovascularization, Pathologic/metabolism
- Organophosphorus Compounds/pharmacology
- Platelet-Derived Growth Factor/genetics
- Platelet-Derived Growth Factor/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptor, Fibroblast Growth Factor, Type 1/genetics
- Receptor, Fibroblast Growth Factor, Type 1/metabolism
- Receptor, Platelet-Derived Growth Factor beta/genetics
- Receptor, Platelet-Derived Growth Factor beta/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Vascular Endothelial Growth Factor A/genetics
- Vascular Endothelial Growth Factor A/metabolism
- Vascular Endothelial Growth Factor Receptor-1/genetics
- Vascular Endothelial Growth Factor Receptor-1/metabolism
Collapse
|
30
|
Extension of the Library of
Biologically Active γ-Alkylidene Butenolides. SYNTHESIS-STUTTGART 2008. [DOI: 10.1055/s-0028-1083181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
31
|
Intracellular metabolism of the new antiviral compound 1-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]-5-azacytosine. Biochem Pharmacol 2008; 76:997-1005. [DOI: 10.1016/j.bcp.2008.08.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Revised: 08/08/2008] [Accepted: 08/11/2008] [Indexed: 11/29/2022]
|
32
|
Synthesis and photophysical properties of 7-deaza-2'-deoxyadenosines bearing bipyridine ligands and their Ru(II)-complexes in position 7. Org Biomol Chem 2008; 6:2852-60. [PMID: 18688477 DOI: 10.1039/b805632c] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The synthesis of the title 7-deazaadenine 2'-deoxyribonucleosides bearing bipyridine, phenanthroline or terpyridine ligands linked to position 7 via an acetylene or phenylene spacer is reported based on aqueous cross-coupling reactions of unprotected 7-iodo-7-deaza-2'-deoxyadenosine with ligand-functionalized acetylenes or boronic acids. The aqueous cross-coupling with acetylene or boronate building blocks containing the Ru(bpy)(3)-type of complex gave the corresponding Ru-containing nucleosides. Photophysical and electrochemical properties were studied and the most efficient type of complex was selected for future luminescent and redox labelling of DNA. The title nucleosides also showed some cytostatic and anti-HCV activities.
Collapse
|
33
|
Biochemical Evaluation of a New Potential Antiviral Drug HPMP-5-Azacytosine. Antiviral Res 2008. [DOI: 10.1016/j.antiviral.2008.01.146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
34
|
Syntheses of pyrimidine acyclic nucleoside phosphonates as potent inhibitors of thymidine phosphorylase (PD-ECGF) from SD-lymphoma. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2008; 26:1025-8. [PMID: 18058530 DOI: 10.1080/15257770701508679] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
In the present study, we synthesized a series of pyrimidine acyclic nucleoside phosphonates bearing a number of substituents in C-5 position of uracil moiety and in the N-1-side chain. In addition, we have investigated in particular the novel syntheses of fluorinated derivatives substituted in the N-1-side chain and uracil C-5 position because fluorine-containing substituents are often powerful modifiers of chemical and biological properties. The obtained compounds exhibit a considerable inhibitory potency of thymidine phosphorylase from SD-lymphoma. In contrast, the synthesized phosphonates are not efficient inhibitors of E. coli and human thymidine phosphorylase.
Collapse
|
35
|
Synthesis, cytostatic and anti-HCV activity of 6-(N-substituted aminomethyl)-, 6-(O-substituted hydroxymethyl)- and 6-(S-substituted sulfanylmethyl)purine nucleosides. Bioorg Med Chem 2008; 16:2329-66. [DOI: 10.1016/j.bmc.2007.11.067] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 11/21/2007] [Accepted: 11/23/2007] [Indexed: 10/22/2022]
|
36
|
Alpha anomer of 5-aza-2′-deoxycytidine down-regulates hTERT mRNA expression in human leukemia HL-60 cells. Biochem Pharmacol 2008; 75:965-72. [DOI: 10.1016/j.bcp.2007.10.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2007] [Revised: 10/11/2007] [Accepted: 10/15/2007] [Indexed: 10/22/2022]
|
37
|
Synthesis, cytostatic, and antiviral activity of novel 6-[2-(dialkylamino)ethyl]-, 6-(2-alkoxyethyl)-, 6-[2-(alkylsulfanyl)ethyl]-, and 6-[2-(dialkylamino)vinyl]purine nucleosides. Bioorg Med Chem 2008; 16:1400-24. [DOI: 10.1016/j.bmc.2007.10.063] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 10/17/2007] [Accepted: 10/18/2007] [Indexed: 11/29/2022]
|
38
|
Pyrimidine acyclic nucleoside phosphonates and phosphorylated analogs. Part 2. Syntheses and investigation of their inhibitory effects towards human thymidine phosphorylase. NUCLEIC ACIDS SYMPOSIUM SERIES (2004) 2008; 52:657-658. [PMID: 18776551 DOI: 10.1093/nass/nrn332] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Various methods were used in the syntheses of a number of pyrimidine acyclic nucleoside phosphonates and their derivatives such as a nucleophilic fluorination, Suzuki-Miyaura coupling reactions and phosphorylation. These new compounds were further investigated for their potential biological activity. Based on results obtained the ability to inhibit human thymidine phosphorylase some of them was found.
Collapse
|
39
|
Synthesis of substituted 6-cyclopropylpurine bases and nucleosides by cross-coupling reactions or cyclopropanations. Org Biomol Chem 2008; 6:2377-87. [DOI: 10.1039/b802833h] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
40
|
Human N6-Methyl-AMP/DAMP Aminohydrolase (Abacavir 5'-Monophosphate Deaminase) is Capable of Metabolizing N6-Substituted Purine Acyclic Nucleoside Phosphonates. ACTA ACUST UNITED AC 2008. [DOI: 10.1135/cccc20080275] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Recombinant human abacavir monophosphate deaminase (hABC-MP deaminase) was compared with the recently described ratN6-methyl-AMP (meAMP) aminohydrolase. hABC-MP deaminase, a 42 kDa polypeptide, exists predominantly as a monomer under non-denaturing conditions. Similar to the rat enzyme, hABC-MP deaminase efficiently catalyzes the hydrolytic deamination of natural substrates meAMP (5),N6,N6-dimethyl-AMP (13) and medAMP (6). Acyclic nucleoside phosphonate (ANP)N6-cyclopropyl-2,6-diamino-9-[2-(phosphonomethoxy)ethyl]purine (cPrPMEDAP) (1), an intermediate intracellular metabolite of antileukemic agent GS-9219, was effectively converted to the corresponding active guanine analog by hABC-MP deaminase. In addition to cPrPMEDAP (1), a number of other biologically activeN6-substituted purine ANPs are alternative substrates for hABC-MP deaminase. The efficiency of their deamination depends on the character ofN6-substitution in the adenine and/or 2,6-diaminopurine ring. ANPs withN6-cyclic substituents are deaminated more readily than corresponding compounds with aliphatic substituents of the same length. The deamination of ANPs is also influenced by modifications at the phosphonoalkyl side chain. Among 9-[2-(phosphonomethoxy)propyl] ANPs, (S)-enantiomers are preferred to (R)-enantiomers. Alternatively, the presence of extended 9-[2-(phosphonoethoxy)ethyl] moiety leads to a moderate increase in the reaction velocity compared to cPrPMEDAP (1). Comparison of hABC-MP deaminase and the rat meAMP aminohydrolase across a broad spectrum ofN6-substituted substrates revealed a strong correlation of their substrate specificities. Similar to the rat meAMP aminohydrolase, hABC-MP deaminase was highly sensitive to deoxycoformycin monophosphate, but not to the guanine product of cPrPMEDAP (1) deamination. Together, these data demonstrate that hABC-MP deaminase is human meAMP aminohydrolase involved in the intracellular activation of biologically activeN6-substituted nucleotide analogs.
Collapse
|
41
|
[Acyclic nucleoside phosphonates as potential antineoplastic agents]. CASOPIS LEKARU CESKYCH 2008; 147:471-477. [PMID: 18988489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Recently, Gilead Sciences (Foster City, CA, USA) presented a potential cytostatic drug GS-9219. It is a novel lipophilic prodrug of cyprPMEDAP, in vivo releasing the active compound PMEG in a two-step process. GS-9219 has shown a substantial therapeutic potential in treatment of spontaneous non-Hodgkin's lymphoma in dogs and its utilization in the human medicine is prospective. Hence, cyprPMEDAP represents a key intermediate in the intracellular activation of GS-9219. Both acyclic nucleoside phosphonates PMEG and cyprPMEDAP, serving as the basis for development of GS-9219, were discovered and their mechanism of action was investigated in detail at the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic. The biological studies using the rat lymphoma were carried out at the First Faculty of Medicine, Charles University.
Collapse
|
42
|
Discovery of 5-Substituted-6-chlorouracils as Efficient Inhibitors of Human Thymidine Phosphorylase. J Med Chem 2007; 50:6016-23. [DOI: 10.1021/jm070644i] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
43
|
Synthesis of 2'-deoxyadenosine nucleosides bearing bipyridine-type ligands and their Ru-complexes in position 8 through cross-coupling reactions. Org Biomol Chem 2007; 5:2849-57. [PMID: 17700854 DOI: 10.1039/b709245h] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis of the title 2'-deoxyadenosine derivatives bearing bipyridine, phenanthroline or terpyridine ligands and their corresponding RuII-complexes in position 8 linked via acetylene or phenylene tethers was accomplished through cross-coupling reactions. The Suzuki-Miyaura reactions of boronic acids or the Sonogashira reactions of terminal acetylene derivatives of oligopyridine ligands were performed either on protected 8-bromoadenosines in organic solvents or, more efficiently, directly on unprotected nucleosides in aqueous acetonitrile or DMF. Direct cross-coupling reactions of unprotected nucleosides with RuII-complexes or the oligopyridine-boronic acids or -acetylenes gave the Ru-labelled nucleosides in one step in fair to good yields. This method was also proven to be applicable for direct Ru-labelling of dATP. Terpyridine-containing 2'-deoxyadenosine exerted significant antiviral and cytostatic effects.
Collapse
|
44
|
Purines Bearing Phenanthroline or Bipyridine Ligands and Their RuII Complexes in Position 8 as Model Compounds for Electrochemical DNA Labeling – Synthesis, Crystal Structure, Electrochemistry, Quantum Chemical Calculations, Cytostatic and Antiviral Activity. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700030] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
45
|
Experimental therapy with 9-[2-(phosphonomethoxy)ethyl]-2,6-diaminopurine (PMEDAP): origin of resistance. Folia Biol (Praha) 2007; 53:79-84. [PMID: 17579998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The role of MRP4 and MRP5 transporters in the acyclic nucleoside phosphonate PMEDAP efflux was studied in vitro (CCRF-CEM cells) and in vivo (spontaneous transplantable T-cell lymphoma of SD/Cub inbred rats). The increased resistance against the cytostatic agent PMEDAP during longterm treatment was found to be associated with overexpression of MRP4 and MRP5 genes. The course of both gene activation differs significantly. While the MRP5 function is important in the onset of PMEDAP resistance, the intensity of the relative MRP4 gene expression increases rather continuously. Our data indicate cooperative acting of both MRP4 and MRP5 genes during the PMEDAP resistance development.
Collapse
|
46
|
Synthesis of Purines Bearing Functionalized C-Substituents by the Conjugate Addition of Nucleophiles to 6-Vinylpurines and 6-Ethynylpurines. European J Org Chem 2006. [DOI: 10.1002/ejoc.200600545] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
47
|
Efficacy of DNA hypomethylating capacities of 5-aza-2'-deoxycytidine and its alpha anomer. Pharmacol Res 2006; 55:16-22. [PMID: 17079159 DOI: 10.1016/j.phrs.2006.09.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Revised: 08/16/2006] [Accepted: 09/25/2006] [Indexed: 11/28/2022]
Abstract
In this paper, we have compared hypomethylating ability of classical beta-d-anomer of 5-aza-2'-deoxycytidine (5-aza-CdRf) and its alpha anomer in cell cultures. Alpha anomers of nucleosides generally exhibit low biological activity compared to their beta counterparts. It is reported that alpha anomer of 5-aza-CdRf efficiently hypomethylated genomic DNA in human T-lymphoblastoid CCRF-CEM cells. Satellite 2 and 18S rDNA were hypomethylated by alpha anomer at concentrations comparable to the beta form. However, the toxicity of the alpha anomer was 4-fold less than that of beta form. Contrast to CCRF-CEM the A549 lung carcinoma cells, possessing negligible level of methylation at repetitive loci, were highly resistant to 5-aza-CdRf treatment suggesting that global genomic methylation might be needed to mediate cytotoxic effect of the drug. Possible mechanisms of inhibition of DNA methylation by alpha anomer are discussed. In conclusion, alpha anomer of 5-aza-CdRf displaying lower host cytotoxicity than the classical beta form may be of potential use in epigenetic therapy.
Collapse
|
48
|
Synthesis and Cytostatic Activity of Novel 6-(Difluoromethyl)purine Bases and Nucleosides. SYNTHESIS-STUTTGART 2006. [DOI: 10.1055/s-2006-942365] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
49
|
N6-Methyl-AMP aminohydrolase activates N6-substituted purine acyclic nucleoside phosphonates. Biochem Pharmacol 2006; 71:1370-6. [PMID: 16513094 DOI: 10.1016/j.bcp.2006.01.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2005] [Revised: 01/23/2006] [Accepted: 01/24/2006] [Indexed: 11/26/2022]
Abstract
In this study we present the identification and characterization of the enzyme involved in the N6-cyclopropyl-2,6-diamino-9-[2-(phosphonomethoxy)ethyl]purine (N6-cyclopropyl-PMEDAP) conversion to biologically active 9-[2-(phosphonomethoxy)ethyl]guanine (PMEG) as well as abacavir 5'-phosphate to carbovir 5'-phosphate. This enzyme was purified from rat liver to homogeneity; it appears to be composed from six 42 kDa subunits and its native form has the molecular weight 260 kDa. This so far unknown enzyme catalyzes conversion of both N6-methyl-AMP and N6-methyl-dAMP to IMP and/or dIMP, respectively. The enzyme acts as 6-(N-substituted amino)purine 5'-nucleotide aminohydrolase with the reaction mechanism very similar to AMP deaminase. The enzyme does not deaminate AMP and dAMP, or the corresponding nucleosides. It is inhibited by deoxycoformycin 5'-phosphate but not by deoxycoformycin or erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA).
Collapse
|
50
|
Design and synthesis of novel 5,6-disubstituted uracil derivatives as potent inhibitors of thymidine phosphorylase. Bioorg Med Chem Lett 2006; 16:1335-7. [PMID: 16337119 DOI: 10.1016/j.bmcl.2005.11.050] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2005] [Revised: 11/14/2005] [Accepted: 11/14/2005] [Indexed: 11/17/2022]
Abstract
We report on a series of novel 5,6-disubstituted uracils with significant inhibitory activity against human and Escherichia coli thymidine phosphorylases. Bis-uracil conjugates were identified as the most potent inhibitors of TPs in this study.
Collapse
|