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Lone MN, Gul S, Mehraj U, Sofi S, Dar AH, Ganie SA, Wani NA, Mir MA, Zargar MA. Synthesis and Biological Evaluation of Novel Uracil Derivatives as Thymidylate Synthase Inhibitors. Appl Biochem Biotechnol 2023; 195:6212-6231. [PMID: 36849711 DOI: 10.1007/s12010-023-04367-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2023] [Indexed: 03/01/2023]
Abstract
Cell division is driven by nucleic acid metabolism, and thymidylate synthase (TYMS) catalyzes a rate-limiting step in nucleotide synthesis. As a result, thymidylate synthase has emerged as a critical target in chemotherapy. 5-Fluorouracil (5-FU) is currently being used to treat a wide range of cancers, including breast, pancreatic, head and neck, colorectal, ovarian, and gastric cancers The objective of this study was to establish a new methodology for the low-cost, one-pot synthesis of uracil derivatives (UD-1 to UD-5) and to evaluate their therapeutic potential in BC cells. One-pot organic synthesis processes using a single solvent were used for the synthesis of drug analogues of Uracil. Integrated bioinformatics using GEPIA2, UALCAN, and KM plotter were utilized to study the expression pattern and prognostic significance of TYMS, the key target gene of 5-fluorouracil in breast cancer patients. Cell viability, cell proliferation, and colony formation assays were used as in vitro methods to validate the in silico lead obtained. BC patients showed high levels of thymidylate synthase, and high expression of thymidylate synthase was found associated with poor prognosis. In silico studies indicated that synthesized uracil derivatives have a high affinity for thymidylate synthase. Notably, the uracil derivatives dramatically inhibited the proliferation and colonization potential of BC cells in vitro. In conclusion, our study identified novel uracil derivatives as promising therapeutic options for breast cancer patients expressing the augmented levels of thymidylate synthase.
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Affiliation(s)
- Mohammad Nadeem Lone
- Department of Chemistry, School of Physical & Chemical Sciences, Central University of Kashmir, Ganderbal, J&K, India
| | - Shazia Gul
- Department of Biotechnology, School of Life Sciences, Central University of Kashmir, Ganderbal, J&K, India
| | - Umar Mehraj
- Department of Bioresources, School of Biological Sciences, University of Kashmir, Srinagar, J&K, India
| | - Shazia Sofi
- Department of Bioresources, School of Biological Sciences, University of Kashmir, Srinagar, J&K, India
| | - Abid Hamid Dar
- Department of Biotechnology, School of Life Sciences, Central University of Kashmir, Ganderbal, J&K, India
| | - Shabir Ahmad Ganie
- Division of Basic Sciences and Humanities FoA, SKUAST-K, Srinagar, J&K, India
| | - Nissar Ahmad Wani
- Department of Biotechnology, School of Life Sciences, Central University of Kashmir, Ganderbal, J&K, India.
| | - Manzoor Ahmad Mir
- Department of Bioresources, School of Biological Sciences, University of Kashmir, Srinagar, J&K, India.
| | - Mohammed A Zargar
- Department of Biotechnology, School of Life Sciences, Central University of Kashmir, Ganderbal, J&K, India.
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Maj P, Mori M, Sobich J, Markowicz J, Uram Ł, Zieliński Z, Quaglio D, Calcaterra A, Cau Y, Botta B, Rode W. Alvaxanthone, a Thymidylate Synthase Inhibitor with Nematocidal and Tumoricidal Activities. Molecules 2020; 25:molecules25122894. [PMID: 32586022 PMCID: PMC7356228 DOI: 10.3390/molecules25122894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/15/2020] [Accepted: 06/19/2020] [Indexed: 11/16/2022] Open
Abstract
With the aim to identify novel inhibitors of parasitic nematode thymidylate synthase (TS), we screened in silico an in-house library of natural compounds, taking advantage of a model of nematode TS three-dimensional (3D) structure and choosing candidate compounds potentially capable of enzyme binding/inhibition. Selected compounds were tested as (i) inhibitors of the reaction catalyzed by TSs of different species, (ii) agents toxic to a nematode parasite model (C. elegans grown in vitro), (iii) inhibitors of normal human cell growth, and (iv) antitumor agents affecting human tumor cells grown in vitro. The results pointed to alvaxanthone as a relatively strong TS inhibitor that causes C. elegans population growth reduction with nematocidal potency similar to the anthelmintic drug mebendazole. Alvaxanthone also demonstrated an antiproliferative effect in tumor cells, associated with a selective toxicity against mitochondria observed in cancer cells compared to normal cells.
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Affiliation(s)
- Piotr Maj
- Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland; (P.M.); (J.S.); (Z.Z.)
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Mattia Mori
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, via Aldo Moro 2, 53100 Siena, Italy; (M.M.); (Y.C.)
| | - Justyna Sobich
- Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland; (P.M.); (J.S.); (Z.Z.)
| | - Joanna Markowicz
- Faculty of Chemistry, Rzeszów University of Technology, 6 Powstańców Warszawy Ave, 35-959 Rzeszów, Poland; (J.M.); (Ł.U.)
| | - Łukasz Uram
- Faculty of Chemistry, Rzeszów University of Technology, 6 Powstańców Warszawy Ave, 35-959 Rzeszów, Poland; (J.M.); (Ł.U.)
| | - Zbigniew Zieliński
- Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland; (P.M.); (J.S.); (Z.Z.)
| | - Deborah Quaglio
- Department of Chemistry and Technology of Drugs, Department of Excellence 2018–2022, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (D.Q.); (A.C.); (B.B.)
| | - Andrea Calcaterra
- Department of Chemistry and Technology of Drugs, Department of Excellence 2018–2022, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (D.Q.); (A.C.); (B.B.)
| | - Ylenia Cau
- Department of Biotechnology, Chemistry and Pharmacy, Department of Excellence 2018-2022, via Aldo Moro 2, 53100 Siena, Italy; (M.M.); (Y.C.)
| | - Bruno Botta
- Department of Chemistry and Technology of Drugs, Department of Excellence 2018–2022, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; (D.Q.); (A.C.); (B.B.)
| | - Wojciech Rode
- Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland; (P.M.); (J.S.); (Z.Z.)
- Correspondence: ; Tel.: +48-608-351-155; Fax: +48-22-822-5342
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Jarmuła A, Wilk P, Maj P, Ludwiczak J, Dowierciał A, Banaszak K, Rypniewski W, Cieśla J, Dąbrowska M, Frączyk T, Bronowska AK, Jakowiecki J, Filipek S, Rode W. Crystal structures of nematode (parasitic T. spiralis and free living C. elegans), compared to mammalian, thymidylate synthases (TS). Molecular docking and molecular dynamics simulations in search for nematode-specific inhibitors of TS. J Mol Graph Model 2017; 77:33-50. [PMID: 28826032 DOI: 10.1016/j.jmgm.2017.08.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/05/2017] [Accepted: 08/07/2017] [Indexed: 01/01/2023]
Abstract
Three crystal structures are presented of nematode thymidylate synthases (TS), including Caenorhabditis elegans (Ce) enzyme without ligands and its ternary complex with dUMP and Raltitrexed, and binary complex of Trichinella spiralis (Ts) enzyme with dUMP. In search of differences potentially relevant for the development of species-specific inhibitors of the nematode enzyme, a comparison was made of the present Ce and Ts enzyme structures, as well as binary complex of Ce enzyme with dUMP, with the corresponding mammalian (human, mouse and rat) enzyme crystal structures. To complement the comparison, tCONCOORD computations were performed to evaluate dynamic behaviors of mammalian and nematode TS structures. Finally, comparative molecular docking combined with molecular dynamics and free energy of binding calculations were carried out to search for ligands showing selective affinity to T. spiralis TS. Despite an overall strong similarity in structure and dynamics of nematode vs mammalian TSs, a pool of ligands demonstrating predictively a strong and selective binding to TsTS has been delimited. These compounds, the E63 family, locate in the dimerization interface of TsTS where they exert species-specific interactions with certain non-conserved residues, including hydrogen bonds with Thr174 and hydrophobic contacts with Phe192, Cys191 and Tyr152. The E63 family of ligands opens the possibility of future development of selective inhibitors of TsTS and effective agents against trichinellosis.
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Affiliation(s)
- Adam Jarmuła
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland.
| | - Piotr Wilk
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland; Macromolecular Crystallography (BESSY-MX), Berlin, Germany
| | - Piotr Maj
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland
| | - Jan Ludwiczak
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland; Centre of New Technologies, University of Warsaw, Warszawa, Poland
| | - Anna Dowierciał
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland
| | - Katarzyna Banaszak
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland
| | - Wojciech Rypniewski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland
| | - Joanna Cieśla
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland
| | - Magdalena Dąbrowska
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland
| | - Tomasz Frączyk
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland
| | | | | | | | - Wojciech Rode
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland
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Wu CW, Liu HC, Yu YL, Hung YT, Wei CW, Yiang GT. Combined treatment with vitamin C and methotrexate inhibits triple-negative breast cancer cell growth by increasing H2O2 accumulation and activating caspase-3 and p38 pathways. Oncol Rep 2017; 37:2177-2184. [PMID: 28259996 DOI: 10.3892/or.2017.5439] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 01/30/2017] [Indexed: 11/06/2022] Open
Abstract
Methotrexate (MTX) is widely used as both an anticancer and anti-rheumatoid arthritis drug. Although MTX has been used to inhibit the growth of many cancer cells, it cannot effectively inhibit growth of triple-negative breast cancer cells (TNBC cells). Vitamin C is an antioxidant that can prevent oxidative stress. In addition, vitamin C has been applied as adjunct treatment for growth inhibition of cancer cells. Recent studies indicated that combined treatment with vitamin C and MTX may inhibit MCF-7 and MDA-MB-231 breast cancer cell growth through G2/M elongation. However, the mechanisms remain unknown. The aim of the present study was to determine whether combined treatment with low-dose vitamin C and MTX inhibits TNBC cell growth and to investigate the mechanisms of vitamin C/MTX-induced cytotoxicity. Neither low-dose vitamin C alone nor MTX alone inhibited TNBC cell growth. However, combined low-dose vitamin C and MTX had synergistic anti-proliferative/cytotoxic effects on TNBC cells. In addition, co-treatment increased H2O2 levels and activated both caspase-3 and p38 cell death pathways.
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Affiliation(s)
- Ching-Wen Wu
- Department of Cardiac Surgery, Tungs' Taichung Metroharbor Hospital, Taichung 435, Taiwan, R.O.C
| | - Hsiao-Chun Liu
- Department of Nursing, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei 231, Taiwan, R.O.C
| | - Yung-Luen Yu
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 404, Taiwan, R.O.C
| | - Yu-Ting Hung
- Department of Nutrition, Master Program of Biomedical Nutrition, Hungkuang University, Taichung 433, Taiwan, R.O.C
| | - Chyou-Wei Wei
- Department of Nutrition, Master Program of Biomedical Nutrition, Hungkuang University, Taichung 433, Taiwan, R.O.C
| | - Giou-Teng Yiang
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei 231, Taiwan, R.O.C
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Ozer U, Barbour KW, Clinton SA, Berger FG. Oxidative Stress and Response to Thymidylate Synthase-Targeted Antimetabolites. Mol Pharmacol 2015; 88:970-81. [PMID: 26443810 DOI: 10.1124/mol.115.099614] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 10/05/2015] [Indexed: 01/09/2023] Open
Abstract
Thymidylate synthase (TYMS; EC 2.1.1.15) catalyzes the reductive methylation of 2'-deoxyuridine-5'-monophosphate (dUMP) by N(5),N(10)-methyhlenetetrahydrofolate, forming dTMP for the maintenance of DNA replication and repair. Inhibitors of TYMS have been widely used in the treatment of neoplastic disease. A number of fluoropyrimidine and folate analogs have been developed that lead to inhibition of the enzyme, resulting in dTMP deficiency and cell death. In the current study, we have examined the role of oxidative stress in response to TYMS inhibitors. We observed that intracellular reactive oxygen species (ROS) concentrations are induced by these inhibitors and promote apoptosis. Activation of the enzyme NADPH oxidase (NOX), which catalyzes one-electron reduction of O2 to generate superoxide (O2 (●-)), is a significant source of increased ROS levels in drug-treated cells. However, gene expression profiling revealed a number of other redox-related genes that may contribute to ROS generation. TYMS inhibitors also induce a protective response, including activation of the transcription factor nuclear factor E2-related factor 2 (NRF2), a critical mediator of defense against oxidative and electrophilic stress. Our results show that exposure to TYMS inhibitors induces oxidative stress that leads to cell death, while simultaneously generating a protective response that may underlie resistance against such death.
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Affiliation(s)
- Ufuk Ozer
- Department of Biological Sciences, and Center for Colon Cancer Research, University of South Carolina, Columbia, South Carolina
| | - Karen W Barbour
- Department of Biological Sciences, and Center for Colon Cancer Research, University of South Carolina, Columbia, South Carolina
| | - Sarah A Clinton
- Department of Biological Sciences, and Center for Colon Cancer Research, University of South Carolina, Columbia, South Carolina
| | - Franklin G Berger
- Department of Biological Sciences, and Center for Colon Cancer Research, University of South Carolina, Columbia, South Carolina
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6
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Yiang GT, Chou PL, Hung YT, Chen JN, Chang WJ, Yu YL, Wei CW. Vitamin C enhances anticancer activity in methotrexate‑treated Hep3B hepatocellular carcinoma cells. Oncol Rep 2014; 32:1057-63. [PMID: 24969544 PMCID: PMC4121419 DOI: 10.3892/or.2014.3289] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 04/25/2014] [Indexed: 02/06/2023] Open
Abstract
Methotrexate (MTX) has been widely used for rheumatoid arthritis therapy for a long time. MTX is also used as an anticancer drug for various tumors. However, many studies have shown that high-dose MTX treatment for cancer therapy may cause liver and renal damage. Alhough the mechanisms involved in MTX-induced liver and renal damage require further research, many studies have indicated that MTX-induced cytotoxicity is associated with increases in oxidative stress and caspase activation. In order to reduce MTX-induced side-effects and increase anticancer efficiency, currently, combination treatments of low-dose MTX and other anticancer drugs are considered and applied for various tumor treatments. The present study showed that MTX induces increases in H2O2 levels and caspase-9/-3 activation leading to cell death in hepatocellular carcinoma Hep3B cells. Importantly, this study is the first to demonstrate that vitamin C can efficiently aid low-dose MTX in inducing cell death in Hep3B cells. Therefore, the present study provides a possible powerful therapeutic method for tumors using a combined treatment of vitamin C and low-dose MTX.
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Affiliation(s)
- Giou-Teng Yiang
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei 231, Taiwan, R.O.C
| | - Pei-Lun Chou
- Division of Allergy-Immunology-Rheumatology, Department of Internal Medicine, Saint Mary's Hospital Luodong, Yilan 265, Taiwan, R.O.C
| | - Yu-Ting Hung
- Department of Nutrition, Master Program of Biomedical Nutrition, Hungkuang University, Shalu, Taichung 433, Taiwan, R.O.C
| | - Jen-Ni Chen
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung 402, Taiwan, R.O.C
| | - Wei-Jung Chang
- Graduate Institute of Cancer Biology, and Center for Molecular Medicine, China Medical University, Taichung 404, Taiwan, R.O.C
| | - Yung-Luen Yu
- Graduate Institute of Cancer Biology, and Center for Molecular Medicine, China Medical University, Taichung 404, Taiwan, R.O.C
| | - Chyou-Wei Wei
- Department of Nutrition, Master Program of Biomedical Nutrition, Hungkuang University, Shalu, Taichung 433, Taiwan, R.O.C
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Hamilton HM, Wilson R, Blythe M, Nehring RB, Fonville NC, Louis EJ, Rosenberg SM. Thymineless death is inhibited by CsrA in Escherichia coli lacking the SOS response. DNA Repair (Amst) 2013; 12:993-9. [PMID: 24075571 DOI: 10.1016/j.dnarep.2013.08.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 08/17/2013] [Accepted: 08/23/2013] [Indexed: 11/18/2022]
Abstract
Thymineless death (TLD) is the rapid loss of colony-forming ability in bacterial, yeast and human cells starved for thymine, and is the mechanism of action of common chemotherapeutic drugs. In Escherichia coli, significant loss of viability during TLD requires the SOS replication-stress/DNA-damage response, specifically its role in inducing the inhibitor of cell division, SulA. An independent RecQ- and RecJ-dependent TLD pathway accounts for a similarly large additional component of TLD, and a third SOS- and RecQ/J-independent TLD pathway has also been observed. Although two groups have implicated the SOS-response in TLD, an SOS-deficient mutant strain from an earlier study was found to be sensitive to thymine deprivation. We performed whole-genome resequencing on that SOS-deficient strain and find that, compared with the SOS-proficient control strain, it contains five mutations in addition to the SOS-blocking lexA(Ind(-)) mutation. One of the additional mutations, csrA, confers TLD sensitivity specifically in SOS-defective strains. We find that CsrA, a carbon storage regulator, reduces TLD in SOS- or SulA-defective cells, and that the increased TLD that occurs in csrA(-) SOS-defective cells is dependent on RecQ. We consider a hypothesis in which the modulation of nucleotide pools by CsrA might inhibit TLD specifically in SOS-deficient (SulA-deficient) cells.
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Affiliation(s)
- Holly M Hamilton
- Departments of Molecular and Human Genetics, Biochemistry and Molecular Biology, Molecular Virology and Microbiology and the Dan L Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030-3411, United States
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8
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In silico screening of chalcone derivatives as potential inhibitors of dihydrofolate reductase: Assessment using molecular docking, paired potential and molecular hydrophobic potential studies. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.dit.2013.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Lee SW, Chen TJ, Lin LC, Li CF, Chen LT, Hsing CH, Hsu HP, Tsai CJ, Huang HY, Shiue YL. Overexpression of thymidylate synthetase confers an independent prognostic indicator in nasopharyngeal carcinoma. Exp Mol Pathol 2013; 95:83-90. [PMID: 23726796 DOI: 10.1016/j.yexmp.2013.05.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 05/21/2013] [Accepted: 05/21/2013] [Indexed: 01/18/2023]
Abstract
Data mining on public domain identified that thymidylate synthetase (TYMS) and dihydrofolate reductase (DHFR) transcripts were significantly higher expressed in nasopharyngeal carcinoma (NPC). In the folate pathway, TYMS catalyzes the methylation of deoxyuridylate to deoxythymidylate using 5,10-methylenetetrahydrofolate [5,10-CH2=THF, derived from tetrahydrofolate (THF)], as a cofactor. This function maintains the thymidine-5-prime monophosphate pool critical for DNA replication and repair and, THF is generated from dihydrofolate (DHF) through the activity of DHFR. Immunoexpression of TYMS and DHFR were retrospectively assessed in biopsies of 124 consecutive NPC patients without initial distant metastasis and treated with consistent guidelines. The outcome was correlated with clinicopathological features and patient survivals. Results indicated that high TYMS (50%) expressions were correlated with primary tumor (p=0.008) and AJCC stage (p=0.006), and high DHFR (50%) expression were correlated with nodal status (p=0.039) and AJCC stage (p=0.029) (7th American Joint Committee on Cancer), respectively. In multivariate analyses, high TYMS expression emerged as an independent prognosticator for worse disease-specific survival (p<0.001), distal metastasis-free survival (p=0.002) and local recurrence-free survival (p<0.001), along with AJCC stage. Therefore, TYMS expression is common and associated with adverse prognosticators and might confer tumor aggressiveness through dysregulation of the nucleotide biosynthetic process.
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Affiliation(s)
- Sung-Wei Lee
- Department of Radiation Oncology, Chi-Mei Medical Center, Liouying, Tainan, Taiwan
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Abstract
The DNA nucleotide thymidylate is synthesized by the enzyme thymidylate synthase, which catalyzes the reductive methylation of deoxyuridylate using the cofactor methylene-tetrahydrofolate (CH(2)H(4)folate). Most organisms, including humans, rely on the thyA- or TYMS-encoded classic thymidylate synthase, whereas, certain microorganisms, including all Rickettsia and other pathogens, use an alternative thyX-encoded flavin-dependent thymidylate synthase (FDTS). Although several crystal structures of FDTSs have been reported, the absence of a structure with folates limits understanding of the molecular mechanism and the scope of drug design for these enzymes. Here we present X-ray crystal structures of FDTS with several folate derivatives, which together with mutagenesis, kinetic analysis, and computer modeling shed light on the cofactor binding and function. The unique structural data will likely facilitate further elucidation of FDTSs' mechanism and the design of structure-based inhibitors as potential leads to new antimicrobial drugs.
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Mishanina TV, Koehn EM, Conrad JA, Palfey BA, Lesley SA, Kohen A. Trapping of an intermediate in the reaction catalyzed by flavin-dependent thymidylate synthase. J Am Chem Soc 2012; 134:4442-8. [PMID: 22295882 DOI: 10.1021/ja2120822] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Thymidylate is a DNA nucleotide that is essential to all organisms and is synthesized by the enzyme thymidylate synthase (TSase). Several human pathogens rely on an alternative flavin-dependent thymidylate synthase (FDTS), which differs from the human TSase both in structure and molecular mechanism. It has recently been shown that FDTS catalysis does not rely on an enzymatic nucleophile and that the proposed reaction intermediates are not covalently bound to the enzyme during catalysis, an important distinction from the human TSase. Here we report the chemical trapping, isolation, and identification of a derivative of such an intermediate in the FDTS-catalyzed reaction. The chemically modified reaction intermediate is consistent with currently proposed FDTS mechanisms that do not involve an enzymatic nucleophile, and it has never been observed during any other TSase reaction. These findings establish the timing of the methylene transfer during FDTS catalysis. The presented methodology provides an important experimental tool for further studies of FDTS, which may assist efforts directed toward the rational design of inhibitors as leads for future antibiotics.
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Chiu YJ, Hour MJ, Lu CC, Chung JG, Kuo SC, Huang WW, Chen HJ, Jin YA, Yang JS. Novel quinazoline HMJ-30 induces U-2 OS human osteogenic sarcoma cell apoptosis through induction of oxidative stress and up-regulation of ATM/p53 signaling pathway. J Orthop Res 2011; 29:1448-56. [PMID: 21425328 DOI: 10.1002/jor.21398] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2010] [Accepted: 02/07/2011] [Indexed: 02/04/2023]
Abstract
Human osteogenic sarcoma is the most common primary bone tumor. Despite of the success of frontline therapy, about 40% of patients have disease progression and further therapy is palliative and toxic. In this study, we developed a novel quinazoline HMJ-30 to investigate the cell growth inhibition and apoptotic responses in U-2 OS human osteogenic sarcoma cells. Our results demonstrated that HMJ-30 significantly reduced cell viabilities of U-2 OS, HOS, and 143B cells in a dose-dependent manner, but it exhibited low cytotoxicity in normal hFOB cells. HMJ-30 induced DNA damage and apoptosis in U-2 OS cells as revealed by morphologic changes, comet assay and DAPI staining. Immuno-staining, colorimetric assays, and Western blotting analyses indicated that activities of caspase-8, caspase-9, and caspase-3 and the levels of Bcl-2 family-related proteins (Bcl-2, Mcl-1, Bax, BAD, and t-Bid) were altered in HMJ-30-treated U-2 OS cells. Pretreatment of cells with caspase-8, -9, and -3 specific inhibitors significantly reduced the cell growth inhibition. HMJ-30-induced apoptosis was mediated through both death-receptor and mitochondria-dependent apoptotic pathways in U-2 OS cells. HMJ-30 induced early phosphorylation of p53(Ser18) was through the activation of ataxia telangiectasia mutated (ATM) in U-2 OS cells. The cell growth inhibition by HMJ-30 was substantially attenuated either by the pre-incubation of U-2 OS cells with N-acetylcysteine (NAC, an antioxidant) and caffeine (an ATM kinase inhibitor) or by p53 knockdown via RNAi. In conclusion, ROS dependent-ATM/p53 signaling pathway is involved in HMJ-30-induced apoptosis in U-2 OS cells.
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Affiliation(s)
- Yu-Jen Chiu
- Department of Pharmacology, School of Medicine, China Medical University, No. 91, Hsueh-Shih Road, Taichung 404, Taiwan
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Abstract
Thymineless death (TLD) is the rapid loss of viability in bacterial, yeast, and human cells starved of thymine. TLD is the mode of action of common anticancer drugs and some antibiotics. TLD in Escherichia coli is accompanied by blocked replication and chromosomal DNA loss and recent work identified activities of recombination protein RecA and the SOS DNA-damage response as causes of TLD. Here, we examine the basis of hypersensitivity to thymine deprivation (hyper-TLD) in mutants that lack the UvrD helicase, which opposes RecA action and participates in some DNA repair mechanisms, RecBCD exonuclease, which degrades double-stranded linear DNA and works with RecA in double-strand-break repair and SOS induction, and RuvABC Holliday-junction resolvase. We report that hyper-TLD in uvrD cells is partly RecA dependent and cannot be attributed to accumulation of intermediates in mismatch repair or nucleotide-excision repair. These data imply that both its known role in opposing RecA and an additional as-yet-unknown function of UvrD promote TLD resistance. The hyper-TLD of ruvABC cells requires RecA but not RecQ or RecJ. The hyper-TLD of recB cells requires neither RecA nor RecQ, implying that neither recombination nor SOS induction causes hyper-TLD in recB cells, and RecQ is not the sole source of double-strand ends (DSEs) during TLD, as previously proposed; models are suggested. These results define pathways by which cells resist TLD and suggest strategies for combating TLD resistance during chemotherapies.
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Fusaro M, Jurkiewicz A, Jarmuła A, Leś A, Rode W. Hypothesis of a proton switch in QM/MM modelling of interaction of dUMP analogues with thymidylate synthase. MOLECULAR SIMULATION 2010. [DOI: 10.1080/08927022.2010.502938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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15
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Dutta SM, Maiti S, Chen G. Effect of folic acid on methotrexate induction of sulfotransferases in rats. Drug Metab Lett 2009; 2:115-119. [PMID: 19356074 DOI: 10.2174/187231208784040997] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Our earlier investigation showed that MTX is an inducer of rat and human sulfotransferases. Here we report that folic acid treatment inhibited MTX induction of aryl sulfotransferase (AST-IV) in female rat liver and hydroxysteroid sulfotransferase (STa) in male rat liver. This is important for understanding the clinical mechanisms of MTX.
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Affiliation(s)
- Sangita Maiti Dutta
- Department of Physiological Sciences, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA
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16
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Mazur AJ, Nowak D, Mannherz HG, Malicka-Błaszkiewicz M. Methotrexate induces apoptosis in CaSki and NRK cells and influences the organization of their actin cytoskeleton. Eur J Pharmacol 2009; 613:24-33. [PMID: 19383496 DOI: 10.1016/j.ejphar.2009.04.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Revised: 04/07/2009] [Accepted: 04/08/2009] [Indexed: 01/08/2023]
Abstract
Methotrexate is a widely used drug in treatments of various types of malignancies and in the therapy of rheumatoid arthritis. The goal of our study was to look at the effect of this dihydrofolate reductase inhibitor on the actin cytoskeleton, since actin plays an important role in cancer transformation and metastasis. For this reason we compared results obtained from experiments on CaSki (human uterine cervix cancer) and NRK (normal fibroblastic rat kidney) cells treated with methotrexate. It has been shown previously that methotrexate can induce apoptosis. Therefore we first examined whether methotrexate induces apoptosis in our model cells. For this aim we applied several assays like Caspase Glo 3/7, DNA fragmentation and binding of phosphatidylserine by annexin V-fluorescein. The data obtained indicated that methotrexate induces programmed cell death in CaSki and NRK cells. However, differences between CaSki and NRK cells were observed in the morphological alterations and dynamics of apoptosis induced by methotrexate. It seemed that cancer cells were more sensitive towards the cell death inducing activity at lower concentrations of methotrexate. Analysis by confocal microscopy of methotrexate-treated cells demonstrated that treatment with this folate antagonist affected the actin cytoskeleton, although the dis-organization of the actin cytoskeleton after treatment with methotrexate differed between cancer and normal cells.
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Affiliation(s)
- Antonina Joanna Mazur
- Department of Anatomy and Embryology, Faculty of Medicine, Ruhr University, Bochum, Germany.
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17
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Yang Z, Waldman AS, Wyatt MD. DNA damage and homologous recombination signaling induced by thymidylate deprivation. Biochem Pharmacol 2008; 76:987-96. [PMID: 18773878 DOI: 10.1016/j.bcp.2008.08.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Revised: 08/05/2008] [Accepted: 08/07/2008] [Indexed: 02/03/2023]
Abstract
DNA damage is accepted as a consequence of thymidylate deprivation induced by chemotherapeutic inhibitors of thymidylate synthase (TS), but the types of damage and signaling responses remain incompletely understood. Thymidylate deprivation increases dUTP and uracil in DNA, which is removed by base excision repair (BER). Because BER requires a synthesis step, strand break intermediates presumably accumulate. Thymidylate deprivation also induces cell cycle arrest during replication. Homologous recombination (HR) is a means of repairing persistent BER intermediates and collapsed replication forks. There are also intimate links between HR and S-phase checkpoint pathways. In this study, the goals were to determine the involvement of HR-associated proteins and DNA damage signaling responses to thymidylate deprivation. When RAD51, which is a central component of HR, was depleted by siRNA cells were sensitized to raltitrexed (RTX), which specifically inhibits TS. To our knowledge, this is the first demonstration in mammalian cells that depletion of RAD51 causes sensitivity to thymidylate deprivation. Activation of DNA damage signaling responses was examined following treatment with RTX. Phosphorylation of replication protein A (RPA2 subunit) and formation of damage-induced foci were strikingly evident following IC(50) doses of RTX. Induction was much more striking following RTX treatment than with hydroxyurea, which is commonly used to inhibit replication. RTX treatment also induced foci of RAD51, gamma-H2AX, phospho-Chk1, and phospho-NBS1, although the extent of co-localization with RPA2 foci varied. Collectively, the results suggest that HR and S-phase checkpoint signaling processes are invoked by thymidylate deprivation and influence cellular resistance to thymidylate deprivation.
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Affiliation(s)
- Zhengguan Yang
- Department of Pharmaceutical and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, 715 Sumter Street, Columbia, SC 29208, USA
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18
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Kang TB, Song SK, Yoon TJ, Yoo YC, Lee KH, Her E, Kim JB. Isolation and characterization of two Korean mistletoe lectins. BMB Rep 2008; 40:959-65. [PMID: 18047792 DOI: 10.5483/bmbrep.2007.40.6.959] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two isolectins (KML-IIU and the KML-IIL) were individually isolated from the previously reported Korean mistletoe lectin, KML-C, by using an immunoaffinity column. Molecular weights of the KML-IIU and the KML-IIL were 64 kDa and 60 kDa respectively. Both of the lectins were composed of heterogeneous A and B subunits linked with a disulfide bond, and showed the same carbohydrate-binding specificities for Gal and GalNAc. However, they are different not only in biophysical properties (glycosylation and amino acid compositions) but also bioactivities (cell killing and cytokine induction). The KML-IIL showed 17-145 times stronger in cytotoxicities to various human and mouse cancer cell lines than the KML-IIU. The KML-IIL also induced TNF-alpha secretion from mouse peritoneal macrophages 4.5 times better than the KML-IIU. The results demonstrated isolectins in Korean mistletoe were varied in bioactivities and the KML-IIL may be developed as an anti-cancer agent.
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Affiliation(s)
- Tae Bong Kang
- School of Food and Biosciences, Handong Global University, Pohang 791-940, Korea
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19
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Abstract
Tetrahydrofolate (THF) polyglutamates are a family of cofactors that carry and chemically activate one-carbon units for biosynthesis. THF-mediated one-carbon metabolism is a metabolic network of interdependent biosynthetic pathways that is compartmentalized in the cytoplasm, mitochondria, and nucleus. One-carbon metabolism in the cytoplasm is required for the synthesis of purines and thymidylate and the remethylation of homocysteine to methionine. One-carbon metabolism in the mitochondria is required for the synthesis of formylated methionyl-tRNA; the catabolism of choline, purines, and histidine; and the interconversion of serine and glycine. Mitochondria are also the primary source of one-carbon units for cytoplasmic metabolism. Increasing evidence indicates that folate-dependent de novo thymidylate biosynthesis occurs in the nucleus of certain cell types. Disruption of folate-mediated one-carbon metabolism is associated with many pathologies and developmental anomalies, yet the biochemical mechanisms and causal metabolic pathways responsible for the initiation and/or progression of folate-associated pathologies have yet to be established. This chapter focuses on our current understanding of mammalian folate-mediated one-carbon metabolism, its cellular compartmentation, and knowledge gaps that limit our understanding of one-carbon metabolism and its regulation.
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Affiliation(s)
- Jennifer T Fox
- Graduate Field of Biochemistry, Molecular and Cellular Biology, Cornell University, Ithaca, New York 14853, USA
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Barbour KW, Berger FG. Cell death in response to antimetabolites directed at thymidylate synthase. Cancer Chemother Pharmacol 2007; 61:189-201. [PMID: 17396263 DOI: 10.1007/s00280-007-0461-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Accepted: 03/06/2007] [Indexed: 02/07/2023]
Abstract
PURPOSE Thymidylate synthase (TS) is an indispensable enzyme in the de novo biosynthesis of TMP during DNA replication and cell growth, and has, therefore, been an important target for several classes of antimetabolites used in cancer chemotherapy. While most investigations of the action of TS-directed agents have focused on apoptosis as the primary means of cell death, little is known regarding the role, if any, of non-apoptotic mechanisms. In the present study, we have examined the mode of cell death induced by several TS inhibitors. METHODS Apoptosis and necrosis in response to TS inhibitors was assessed. The roles of caspases and the transcriptional regulator nuclear factor kappa B (NFkappaB) in drug-induced cell death were analyzed. Finally, drug-mediated changes in expression of several proteins involved in regulation of apoptosis were analyzed. RESULTS Though human colon tumor cells exposed to TS inhibitors undergo classical apoptosis, it is not the predominant mechanism of response; rather, a necrosis-like mechanism prevails. The apoptotic response to TS inhibitors is caspase-dependent, and is promoted by NFkappaB. In contrast, the necrosis-like response is independent of both caspases and NFkappaB. Exposure to TS inhibitors induces PARP cleavage, but does not alter expression of the pro or activated forms of caspases-3 or caspases-8, Fas, or FasL. Treatment with the death-inducing cytokine TNFalpha, like TS inhibitors, results in a limited extent of apoptosis that is both caspase- and NFkappaB-dependent; however, unlike TS inhibitors, the cytokine does not induce necrosis. CONCLUSION Classical apoptosis occurs to a limited extent in human colon tumor cells exposed to TS inhibitors, with caspase-independent necrosis being the prinicipal mechanism of cell death. We suggest that the role of necrosis and necrosis-like mechanisms should be considered in future studies of the action of TS-directed antimetabolites, as well as other chemotherapeutic agents.
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Affiliation(s)
- Karen W Barbour
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
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21
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Peña M, Xing Y, Koli S, Berger F. Role of N-terminal residues in the ubiquitin-independent degradation of human thymidylate synthase. Biochem J 2006; 394:355-63. [PMID: 16259621 PMCID: PMC1386034 DOI: 10.1042/bj20051479] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Thymidylate synthase (TS) catalyses the reductive methylation of dUMP to form dTMP, a reaction that is essential for maintenance of nucleotide pools during cell growth. Because the enzyme is indispensable for DNA replication in actively dividing cells, it is an important target for cytotoxic drugs used in cancer chemotherapy, including fluoropyrimidines (e.g. 5-fluorouracil and 5-fluoro-2'-deoxyuridine) and anti-folates (e.g. raltitrexed, LY231514, ZD9331 and BW1843U89). These drugs generate metabolites that bind to the enzyme's active site and inhibit catalytic activity, leading to thymidylate deprivation and cellular apoptosis. Ligand binding to TS results in stabilization of the enzyme and an increase in its intracellular concentration. Previously, we showed that degradation of the TS polypeptide is carried out by the 26 S proteasome in a ubiquitin-independent manner. Such degradation is directed by the disordered N-terminal region of the TS polypeptide, and is abrogated by ligand binding. In the present study, we have verified the ubiquitin-independent nature of TS proteolysis by showing that a 'lysine-less' polypeptide, in which all lysine residues were replaced by arginine, is still subject to proteasome-mediated degradation. In addition, we have mapped the structural determinants of intracellular TS degradation in more detail and show that residues at the N-terminal end of the molecule, particularly the penultimate amino acid Pro2, play an important role in governing the half-life of the enzyme. This region is capable on its own of destabilizing an evolutionarily distinct TS molecule that normally lacks this domain, indicating that it functions as a degradation signal. Interestingly, degradation of an intrinsically unstable mutant form of TS, containing a Pro-->Leu substitution at residue 303, is directed by C-terminal, rather than N-terminal, sequences. The implications of these findings for the control of TS expression, and for the regulation of protein degradation in general, are discussed.
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Affiliation(s)
- Maria Marjorette O. Peña
- Department of Biological Sciences, University of South Carolina, 715 Sumter Street, Columbia, SC 29208, U.S.A
| | - Yang Yang Xing
- Department of Biological Sciences, University of South Carolina, 715 Sumter Street, Columbia, SC 29208, U.S.A
| | - Sangita Koli
- Department of Biological Sciences, University of South Carolina, 715 Sumter Street, Columbia, SC 29208, U.S.A
| | - Franklin G. Berger
- Department of Biological Sciences, University of South Carolina, 715 Sumter Street, Columbia, SC 29208, U.S.A
- To whom correspondence should be addressed (email )
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22
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Jantová S, Letasiová S, Repický A, Ovádeková R, Lakatos B. The effect of 3-(5-nitro-2-thienyl)-9-chloro-5-morpholin-4-yl[1,2,4]triazolo[4,3-c]quinazoline on cell growth, cell cycle, induction of DNA fragmentation, and activity of caspase 3 in murine leukemia L1210 cells and fibroblast NIH-3T3 cells. Cell Biochem Funct 2006; 24:519-30. [PMID: 16342136 DOI: 10.1002/cbf.1296] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Quinazolines are multitarget agents, which have broad spectrum of biological activity, and some of them are now in cancer clinical testing. 3-(5-nitro-2-thienyl)-9-chloro-5-morpholin-4-yl[1,2,4]triazolo[4,3-c]quinazoline is a new synthetically prepared derivative, which in our previous study showed cytotoxic effects on cancer cell lines HeLa and B16. Quinazoline, at micromolar concentrations, induced morphological changes and necrosis of B16 cells, and at nanomolar concentrations it produced changes of F-actin cytoskeleton. It did not cause changes in the cell cycle, did not induce apoptotic cell death in B16 cells, did not have a mutagenic effect, and did not even behave as a typical intercalating agent. Little significant reduction of tumor volume in intramuscular transplanted B16 cells was observed. The aim of the present study was to examine the cytotoxic effect of 3-(5-nitro-2-thienyl)-9-chloro-5-morpholin-4-yl[1,2,4]triazolo[4,3-c]quinazoline on murine leukemia L1210 cells and fibroblast NIH-3T3 cells. Induction of cell morphology and cell cycle changes, induction of apoptosis and caspase 3 activity were studied. Quinazoline acted cytotoxically on both cell lines. The sensitivity of leukemia L1210 cells to the quinazoline was higher than that of fibroblast NIH-3T3. The IC(100) was 12 microM for L1210 cells and 24 microM for NIH-3T3 cells. No effect of quinazoline on the cell cycle profile of L1210 and NIH-3T3 was detected, however, quinazoline induced an increase of the sub-G(0) cell fraction, apoptotic DNA fragmentation, and apoptotic morphological changes at a concentration of 12 microM. This quinazoline concentration induced caspase 3 activity. Our results demonstrated that induction of apoptotic cell death via activation of caspase 3 contributed to the cytotoxic effects of 3-(5-nitro-2-thienyl)-9-chloro-5-morpholin-4-yl[1,2,4]triazolo[4,3-c]quinazoline in murine leukemia L1210 cells.
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Affiliation(s)
- S Jantová
- Department of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK-81237 Bratislava, Slovak Republic.
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23
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Ovádeková R, Jantová S, Theiszová M, Labuda J. Cytotoxicity and detection of damage to DNA by 3-(5-nitro-2-thienyl)-9-chloro-5-morpholin-4-yl[1,2,4]triazolo[4,3-c] quinazoline on human cancer cell line HeLa. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2005; 149:455-9. [PMID: 16601809 DOI: 10.5507/bp.2005.079] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Quinazolines - 1,3-benzodiazines are biological active compounds, which are used in the phamaceutical industry, in agriculture and in the medicine. As documented in the literature, many derivatives demonstrated anticancer activity and they act as multitarget agents. 3-(5-Nitro-2-thienyl)-9-chloro-5-morpholin-4-yl[1,2,4]triazolo[4,3-c] quinazoline (NTCHMTQ) - a new synthetically prepared quinazoline derivative was the most effective derivative in our primary cytotoxic screening. In this study, we evaluated cytotoxic/antiproliferative activity of NTCHMTQ using human tumor cell line HeLa. Possible interaction of 3-(5-nitro-2-thienyl)-9-chloro-5-morpholin-4-yl[1,2,4]triazolo[4,3-c] quinazoline with calf thymus DNA was tested by the DNA - modified screen - printed electrode. Quinazoline derivative acted cytotoxically on tumor cell line HeLa. The IC(100) value was 10 microg/ml. The IC(50) values was found to be less than 4 microg/ml, a limit put forward by the National Cancer Institute (NCI) for classification of he compound as a potential anticancer drug. Quinazoline at micromolar concentrations induced morphological changes and necrosis of HeLa cells. Using the DNA based electrochemical biosensor, we have not found damage to DNA under in vitro conditions at an incubation of the biosensor in mixture with quinazoline.
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Affiliation(s)
- Renáta Ovádeková
- Department of Analytical Chemistry, Slovak University of Technology, Radlinského 9, Bratislava, Slovak Republic.
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24
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Temmink OH, Hoogeland MFM, Fukushima M, Peters GJ. Low folate conditions may enhance the interaction of trifluorothymidine with antifolates in colon cancer cells. Cancer Chemother Pharmacol 2005; 57:171-9. [PMID: 16010590 DOI: 10.1007/s00280-005-0033-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Accepted: 04/16/2005] [Indexed: 10/25/2022]
Abstract
PURPOSE Trifluorothymidine (TFT) is a fluoropyrimidine that is part of the novel combination metabolite TAS-102, in which TFT is combined with a potent thymidine phosphorylase inhibitor (TPI). TAS-102 is currently tested as an orally chemotherapeutic agent in different schedules in a phase I study. In its monophosphate form, TFT can inhibit thymidylate synthase (TS) activity after binding to the TS-nucleotide binding site leading to dTTP depletion, and in its triphosphate form TFT is incorporated into DNA, eventually leading to DNA damage. In this in vitro study, we investigated whether TFT could potentiate cytotoxicity of the antifolate-based TS inhibitors AG337 (Nolatrexed), ZD1694 (Raltitrexed) and GW1843; and whether increased TS inhibition or DNA damage would be related to this result. METHODS The drug combinations were studied in colon cancer cell lines either grown at low or high folate conditions. Multiple drug effect analysis was performed after measuring growth inhibition when the drugs were combined (MTT Assay) and expressed as Combination Index (CI), where CI<0.9 indicates synergism, CI=0.9-1.1 indicates additivity and CI>1.1 indicates antagonism. Drug target analysis was performed using the TS in situ inhibition assay and the FADU DNA-damage assay. Cells were exposed to either the drugs alone or in combination to determine the effect on TS activity and DNA damage induction, respectively. RESULTS Three experimental procedures were used to test the interaction of the drugs: either one of the drugs was kept at a constant concentration (IC25) or two drugs were added in a 1:1 IC50-based molar ratio. The combinations of TFT with one of the antifolates in which one of the drugs was kept at a constant concentration were synergistic for all antifolates in WiDr/F cells, which grow in low folate medium (CI=0.6-0.8), but only additive to antagonistic for the cell lines growing in high folate medium: TFT-AG337: CI=0.9-2.3; TFT-ZD1694: CI=0.9-1.3; TFT-GW1843: CI=0.8-1.7. The procedure in which the two drugs were added in a 1:1 IC50-based molar ratio showed antagonism for all three combinations in all cell lines (CI>2.7). TS inhibition (14.3%) and DNA damage (8%) were more pronounced than expected (P<0.05) when TFT was combined with GW1843 in WiDr/F cells, in contrast to AG337 and ZD1694, which showed inhibiting effects as expected (additive). CONCLUSIONS The combination of TFT with the antifolates AG337, ZD1694 and GW1843 is mainly additive when the drugs are given simultaneously and this is mediated by an additive TS inhibition and DNA damage. The drug interaction may partly be dependent on the folate homeostasis since WiDr/F cells growing at low folate conditions show pronounced synergism in growth inhibition, two-sided TS inhibition and DNA damage, especially when TFT is combined with the tight-binding TS inhibitor GW1843.
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Affiliation(s)
- Olaf H Temmink
- Department of Medical Oncology, VU University Medical Center, De Boelelaan 1117, P.O. Box 7057, 1007, MB, Amsterdam, The Netherlands
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25
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Jantová S, Ovádeková R, Letasiová S, Spirková K, Stankovský S. Antimicrobial activity of some substituted triazoloquinazolines. Folia Microbiol (Praha) 2005; 50:90-4. [PMID: 16110909 DOI: 10.1007/bf02931453] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fifteen substituted 1,2,4-triazolo[4,3-c]quinazolines were tested for antibacterial and antifungal effects. The most effective derivatives had the triazoloquinazoline skeleton substituted with the pharmacologically active chromophores--morpholine, chlorine and nitro group. The broadest antimicrobial activity was found with 5-morpholin-4-yl-3-(5-nitrothien-2-yl)[1,2,4]triazolo[4,3-c]quinazoline in concentration of 10 mg/L for B. subtilis, 50 mg/L for S. aureus and 100 mg/L for C. tropicalis. The highest tested concentration of derivative caused 83% growth inhibition of R. nigricans.
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Affiliation(s)
- S Jantová
- Department of Biochemistry and Microbiology, Slovak University of Technology, 812 37 Bratislava, Slovakia
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26
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Schultz RM. Preclinical development of Alimta (Pemetrexed, LY231514), a multitargeted antifolate. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2005; 63:275-300. [PMID: 16265884 DOI: 10.1007/3-7643-7414-4_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Affiliation(s)
- Richard M Schultz
- Division of Cancer Research, Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285, USA.
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27
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Synthesis of Nonclassical Quinazolinone Antifolates as Thymidylate Synthase Inhibitors and Their Antitumor Activity In Vitro. B KOREAN CHEM SOC 2004. [DOI: 10.5012/bkcs.2004.25.12.1898] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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28
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Forsthoefel AM, Peña MMO, Xing YY, Rafique Z, Berger FG. Structural determinants for the intracellular degradation of human thymidylate synthase. Biochemistry 2004; 43:1972-9. [PMID: 14967037 DOI: 10.1021/bi035894p] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thymidylate synthase (EC 2.1.1.45) (TS) catalyzes the conversion of dUMP to dTMP and is therefore indispensable for DNA replication in actively dividing cells. The enzyme is a critical target at which chemotherapeutic agents such as fluoropyrimidines (e.g., 5-fluorouracil and 5-fluoro-2'-deoxyuridine) and folic acid analogues (e.g., raltitrexed, LY231514, ZD9331, and BW1843U89) are directed. These agents exert their effects through the generation of metabolites that bind the active site of TS and inhibit catalytic activity. The binding of ligands to the TS molecule leads to dramatic changes in the conformation of the enzyme, particularly within the C-terminal domain. Stabilization of the enzyme and an increase in its intracellular level are associated with ligand binding and may be important in cellular response to TS-directed drugs. In the present study, we have examined molecular features of the TS molecule that control its degradation. We find that the C-terminal conformational shift is not required for ligand-mediated stabilization of the enzyme. In addition, we demonstrate that the N-terminus of the TS polypeptide, which is extended in the mammalian enzyme and is disordered in crystal structures, is a primary determinant of the enzyme's half-life. Finally, we show that TS turnover is carried out by the 26S proteasome in a ubiquitin-independent manner. These findings provide the basis for a mechanistic understanding of TS degradation and its regulation by antimetabolites.
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Affiliation(s)
- Antonia M Forsthoefel
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA
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29
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Makowski M, Pawełczak K, Kafarski P, Dzik JM, Gołos B, Balinska M, Rode W. Quinazoline Antifolate Thymidylate Synthase Inhibitors: Replacement of Glutamic Acid by Aminophosphonic Acids. PHOSPHORUS SULFUR 2003. [DOI: 10.1080/10426500307844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Maciej Makowski
- a Institute of Chemistry , University of Opole , Opole, Poland
| | | | | | - Jolanta M. Dzik
- c Nencki Institute of Experimental Biology , Warszawa, Poland
| | - Barbara Gołos
- c Nencki Institute of Experimental Biology , Warszawa, Poland
| | | | - Wojciech Rode
- c Nencki Institute of Experimental Biology , Warszawa, Poland
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30
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Ferrini JB, Jbilo O, Peleraux A, Combes T, Vidal H, Galiegue S, Casellas P. Transcriptomic classification of antitumor agents: application to the analysis of the antitumoral effect of SR31747A. Gene Expr 2003; 11:125-39. [PMID: 14686786 PMCID: PMC5991160 DOI: 10.3727/000000003108749026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/10/2003] [Indexed: 11/24/2022]
Abstract
SR31747A is a sigma ligand that exhibits a potent antitumoral activity on various human tumor cell lines both in vitro and in vivo. To understand its mode of action, we used DNA microarray technology combined with a new bioinformatic approach to identify genes that are modulated by SR31747A in different human breast or prostate cancer cell lines. The SR31747A transcriptional signature was also compared with that of seven different representative anticancer drugs commonly used in the clinic. To this aim, we performed a two-dimensional hierarchical clustering analysis of drugs and genes which showed that 1) standard molecules with similar mechanism of action clustered together and 2) SR31747A does not belong to any previously characterized class of standard anticancer drugs. Moreover, we showed that 3) SR31747A mainly exerted its antiproliferative effect by inhibiting the expression of genes playing a key role in DNA replication and cell cycle progression. Finally, contrasting with other drugs, we obtained evidence that 4) SR31747A strongly inhibited the expression of three key enzymes of the nucleotide synthesis pathway (i.e., dihydrofolate reductase, thymidylate synthase, and thymidine kinase) with the latter shown both at the mRNA and protein levels. These results, obtained through a novel molecular approach to characterize and compare anticancer agents, showed that SR31747A exhibits an original mechanism of action, very likely through unexpected targets whose modulations may account for its antitumoral effect.
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Affiliation(s)
- Jean-Bernard Ferrini
- Immunology-Oncology Department, Sanofi˜Synthelabo Recherche, 371 rue Prof. Blayac, F-34184 Montpellier CEDEX 04, France
| | - Omar Jbilo
- Immunology-Oncology Department, Sanofi˜Synthelabo Recherche, 371 rue Prof. Blayac, F-34184 Montpellier CEDEX 04, France
| | - Annick Peleraux
- Immunology-Oncology Department, Sanofi˜Synthelabo Recherche, 371 rue Prof. Blayac, F-34184 Montpellier CEDEX 04, France
| | - Therese Combes
- Immunology-Oncology Department, Sanofi˜Synthelabo Recherche, 371 rue Prof. Blayac, F-34184 Montpellier CEDEX 04, France
| | - Hubert Vidal
- Immunology-Oncology Department, Sanofi˜Synthelabo Recherche, 371 rue Prof. Blayac, F-34184 Montpellier CEDEX 04, France
| | - Sylvaine Galiegue
- Immunology-Oncology Department, Sanofi˜Synthelabo Recherche, 371 rue Prof. Blayac, F-34184 Montpellier CEDEX 04, France
| | - Pierre Casellas
- Immunology-Oncology Department, Sanofi˜Synthelabo Recherche, 371 rue Prof. Blayac, F-34184 Montpellier CEDEX 04, France
- Address correspondence to Pierre Casellas, Sanofi-Synthelabo Recherche, 371 rue du Professeur Joseph Blayac, F-34184 Montpellier cedex 04, France. Tel: (33) 4 67 10 62 90; Fax: (33) 4 67 10 60 00; E-mail:
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31
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Christopherson RI, Lyons SD, Wilson PK. Inhibitors of de novo nucleotide biosynthesis as drugs. Acc Chem Res 2002; 35:961-71. [PMID: 12437321 DOI: 10.1021/ar0000509] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Potent inhibitors of enzymes catalyzing reactions in the de novo pathways for biosynthesis of purine and pyrimidine nucleotides are synthetic or natural-product analogues of pathway intermediates or, more recently, inhibitors rationally designed from a knowledge of the catalytic mechanism. Such inhibitors may be effective drugs against cancer, inflammatory disorders, or various infections. For human cancer, the purine pathway may be a better target for inhibition than the pyrimidine pathway, where toxic side effects are more apparent. Drugs such as methotrexate and 6-mercaptopurine have multiple sites of action, making it difficult to quantitatively predict their effects upon cells. Rational design of inhibitors based upon the X-ray structure of the target enzyme has the prospect of yielding drugs with only one site of action in human cells. Such a drug is VX-497, a potent inhibitor of the purine enzyme, IMP dehydrogenase.
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Affiliation(s)
- Richard I Christopherson
- School of Molecular and Microbial Biosciences, University of Sydney, Sydney, NSW, 2006, Australia.
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32
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Blanchard S, Rodriguez I, Kuehm-Caubère C, Renard P, Pfeiffer B, Guillaumet G, Caubère P. Hetarynic synthesis and chemical transformation of dihydrodipyridopyrazines. Tetrahedron 2002. [DOI: 10.1016/s0040-4020(02)00310-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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33
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Backus HH, Wouters D, van der Wilt CL, Kuiper CM, van Groeningen CJ, Pinedo HM, Peters GJ. Thymidylate synthase inhibition induces p53 dependent and independent cell death. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2002; 486:303-6. [PMID: 11783505 DOI: 10.1007/0-306-46843-3_59] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Affiliation(s)
- H H Backus
- Department of Oncology, University Hospital Vrije Universiteit, Amsterdam, The Netherlands
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34
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Correale P, Sabatino M, Cusi MG, Micheli L, Nencini C, Pozzessere D, Petrioli R, Aquino A, De Vecchis L, Turriziani M, Prete SP, Sanguedolce R, Rausa L, Giorgi G, Francini G. In vitro generation of cytotoxic T lymphocytes against HLA-A2.1-restricted peptides derived from human thymidylate synthase. J Chemother 2001; 13:519-26. [PMID: 11760216 DOI: 10.1179/joc.2001.13.5.519] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
5-Fluorouracil (5-FU) is a pyrimidine antimetabolite active against colorectal carcinoma and other malignancies of the digestive tract. Over-expression or mutation of thymidylate synthase (TS), the target enzyme of the 5-FU metabolite, 5-fluorodeoxyuridine monophosphate, is strictly correlated with cancer cell resistance to 5-FU. On this basis we investigated whether TS is a potential target for active specific immunotherapy of human colon carcinoma, which acquires resistance to 5-FU. Three TS-derived epitope peptides which fit defined amino acid consensus motifs for HLA-A2.1 binding were synthesized and investigated for their ability to induce human TS-specific cytotoxic T cell (CTL) responses in vitro. CTL lines specific for each peptide were established by stimulating peripheral blood mononuclear cells (PBMC) from an HLA-A2.1+ healthy donor with autologous dendritic cells loaded with TS peptide. Specific CTL lines showed HLA-A2.1-restricted cytotoxicity in vitro to HLA-A2.1+ target cells pulsed with the specific TS peptide and to HLA-class I matching colon carcinoma target cells over-expressing TS enzyme after exposure to 5-FU. Recognition by CTL lines suggests that these TS peptides may be potential candidates for use in a peptide-based vaccine against 5-FU resistant colon carcinoma.
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Affiliation(s)
- P Correale
- Oncopharmacology Center, School of Medicine, University of Siena, Italy
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35
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Oh SW, Ha JR, Baek DJ. In vivo antitumor efficacy of CW252053, a folate-based thymidylate synthase inhibitor. Arch Pharm Res 2001; 24:323-6. [PMID: 11534765 DOI: 10.1007/bf02975100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Previous studies have demonstrated that CW252053, a quinazoline antifolate, exhibits potent inhibitory activity against thymidylate synthase (TS) as well as cytotoxic activity against tumor cell lines in vitro. In this study, we evaluated the in vivo antitumor efficacy of CW252053 in the mouse tumor model. Female B6D2F1 mice were injected with LY3.7.2C TK-/- (thymidine kinase deficient mouse lymphoma) cells into the gastrocnemius muscle. Then, CW252053 was administered twice daily by intraperitoneal injection for 10 days, and tumor growth was monitored daily by leg diameter measurement. All animals in the vehicle, 5-FU, and low dose (30 mg/kg) CW252053 treated groups died between days 12 and 23 because of the tumor burden. In contrast, dosing with 60 mg/kg of CW252053 produced a cure rate against tumor growth of 37.5% and a survival rate of 50%. Even more significantly, a higher dose of CW252053 (120 mg/kg) elicited both a 100% cure rate and a 100% survival rate at the termination of the study, confirming that this compound has very potent in vivo antitumor activity against tumor growth. During the experimental period of this study no signs of toxicity were observed even at the high CW252053 dosage rate of 120 mg/kg.
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Affiliation(s)
- S W Oh
- Research Laboratory, R & D Division, Choongwae Pharma Co., Suwon, Korea
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36
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Backus HH, Pinedo HM, Wouters D, Padrón JM, Molders N, van Der Wilt CL, van Groeningen CJ, Jansen G, Peters GJ. Folate depletion increases sensitivity of solid tumor cell lines to 5-fluorouracil and antifolates. Int J Cancer 2000; 87:771-8. [PMID: 10956384 DOI: 10.1002/1097-0215(20000915)87:6<771::aid-ijc2>3.0.co;2-v] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Cancer cell lines in standard cell culture medium or in animal models are surrounded by an environment with relatively high folate (HF) levels, compared with folate levels in human plasma. In the present study we adapted 4 colon cancer (C26-A, C26-10, C26-G and WiDr) and 3 squamous cell carcinoma of the head and neck (HNSCC) cell lines (11B, 14C and 22B) to culture medium with low folate (LF) levels (2.5, 1.0 and 0.5 nM, respectively) and investigated whether folate depletion had an effect on sensitivity to antifolates and which mechanisms were involved. All LF cell lines showed a higher sensitivity to 5-fluorouracil (5-FU) alone or in combination with leucovorin (LV) (2-5-fold), to the thymidylate synthase (TS) inhibitors, AG337 (2-7-fold), ZD1694 (3-49-fold), ZD9331 (3-40-fold), LY231514 (2-21-fold) or GW1843U89 (4-29-fold) or to the dihydrofolate reductase (DHFR) inhibitor PT523 (2-50-fold) compared with their HF variants cultured in standard medium containing up to 8 microM folic acid. LV could only increase sensitivity to 5-FU in HNSCC cell lines 14C and 14C/F. The differences in sensitivity could partially be explained by a 2-7-fold increased transport activity of the reduced folate carrier (RFC) in LF cell lines, whereas no significant change in folylpolyglutamate synthetase (FPGS) activity was observed. Furthermore, the protein expression and catalytic activity of the target enzyme TS were up to 7-fold higher in HF colon cancer cells compared with the LF variants (p < 0.05). Although the TS protein expression in LF HNSCC cells was also lower than in HF variants, the TS catalytic activity and FdUMP binding sites were up to 3-fold higher (p < 0.05). Thus, changes in TS levels were associated with differences in sensitivity. These results indicate that folate depletion was associated with changes in TS and RFC levels which resulted in an increase in sensitivity to 5-FU and antifolates. The folate levels in LF medium used in this study are more representative for folate levels in human plasma and therefore these data could be more predictive for the activity of 5-FU and antifolates in a clinical setting than results obtained from cell lines cultured in HF medium or in animal models.
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Affiliation(s)
- H H Backus
- Department of Medical Oncology, University Hospital Vrije Universiteit, Amsterdam, The Netherlands
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37
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Backus HH, Pinedo HM, Wouters D, Padrón JM, Molders N, van Der Wilt CL, van Groeningen CJ, Jansen G, Peters GJ. Folate depletion increases sensitivity of solid tumor cell lines to 5-fluorouracil and antifolates. Int J Cancer 2000. [PMID: 10956384 DOI: 10.1002/1097-0215(20000915)87:6%3c771::aid-ijc2%3e3.0.co;2-v] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cancer cell lines in standard cell culture medium or in animal models are surrounded by an environment with relatively high folate (HF) levels, compared with folate levels in human plasma. In the present study we adapted 4 colon cancer (C26-A, C26-10, C26-G and WiDr) and 3 squamous cell carcinoma of the head and neck (HNSCC) cell lines (11B, 14C and 22B) to culture medium with low folate (LF) levels (2.5, 1.0 and 0.5 nM, respectively) and investigated whether folate depletion had an effect on sensitivity to antifolates and which mechanisms were involved. All LF cell lines showed a higher sensitivity to 5-fluorouracil (5-FU) alone or in combination with leucovorin (LV) (2-5-fold), to the thymidylate synthase (TS) inhibitors, AG337 (2-7-fold), ZD1694 (3-49-fold), ZD9331 (3-40-fold), LY231514 (2-21-fold) or GW1843U89 (4-29-fold) or to the dihydrofolate reductase (DHFR) inhibitor PT523 (2-50-fold) compared with their HF variants cultured in standard medium containing up to 8 microM folic acid. LV could only increase sensitivity to 5-FU in HNSCC cell lines 14C and 14C/F. The differences in sensitivity could partially be explained by a 2-7-fold increased transport activity of the reduced folate carrier (RFC) in LF cell lines, whereas no significant change in folylpolyglutamate synthetase (FPGS) activity was observed. Furthermore, the protein expression and catalytic activity of the target enzyme TS were up to 7-fold higher in HF colon cancer cells compared with the LF variants (p < 0.05). Although the TS protein expression in LF HNSCC cells was also lower than in HF variants, the TS catalytic activity and FdUMP binding sites were up to 3-fold higher (p < 0.05). Thus, changes in TS levels were associated with differences in sensitivity. These results indicate that folate depletion was associated with changes in TS and RFC levels which resulted in an increase in sensitivity to 5-FU and antifolates. The folate levels in LF medium used in this study are more representative for folate levels in human plasma and therefore these data could be more predictive for the activity of 5-FU and antifolates in a clinical setting than results obtained from cell lines cultured in HF medium or in animal models.
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Affiliation(s)
- H H Backus
- Department of Medical Oncology, University Hospital Vrije Universiteit, Amsterdam, The Netherlands
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38
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Jantová S, Greif G, Spirková K, Stankovský S, Oravcová M. Antibacterial effects of trisubstituted quinazoline derivatives. Folia Microbiol (Praha) 2000; 45:133-7. [PMID: 11271820 DOI: 10.1007/bf02817411] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Five trisubstituted quinazolones and eight trisubstituted quinazoline-4-thiones have been tested for antibacterial effects by a microdilution method. Four derivatives exerted a significant effect on E. coli, P. aeruginosa, S. aureus and B. subtilis (IC50 < 100 mg/L). In the bacterium P. aeruginosa six quinazolines showed a higher antibacterial effect than ampicillin. The most sensitive to the effects of the quinazolines was S. aureus; a concentration of 100 mg/L of six derivatives induced a bacteriostatic effect on S. aureus. The quinazoline-4-thiones were generally more active than the quinazolones. All the tested concentrations of the four most effective quinazolines influenced the specific growth rate.
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Affiliation(s)
- S Jantová
- Department of Biochemistry and Microbiology, Faculty of Chemical Technology, Slovak University of Technology, 812 37 Bratislava, Slovakia
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39
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Jantová S, Spirková K, Stankovský S, Duchonová P. Antibacterial effect of some substituted tricyclic quinazolines and their synthetic precursors. Folia Microbiol (Praha) 1999; 44:187-90. [PMID: 10588054 DOI: 10.1007/bf02816240] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Eleven substituted tricyclic quinazolines and their synthetic precursors were tested for antibacterial effects. 3-Chloromethylcarbonyl-2-methylquinazolin-4-thione and 5-phenyl-2,3-dihydro-1,2,4-triazolo[4,3-c]quinazolin-3-one had the highest antibacterial effect against Bacillus subtilis, the MIC values being 50 mg/L. Two tested derivatives were more active against Pseudomonas aeruginosa than ampicillin, the IC50 values being 80 and 100 mg/L. The most effective derivatives contained in the structure generally pharmacologically active chromophores--methyl group in position 2 and a chloromethyl configuration on the carbonyl group in position 3.
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Affiliation(s)
- S Jantová
- Department of Biochemistry and Microbiology, Faculty of Chemical Technology, Slovak University of Technology, Bratislava, Slovakia
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40
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Kitchens ME, Forsthoefel AM, Barbour KW, Spencer HT, Berger FG. Mechanisms of acquired resistance to thymidylate synthase inhibitors: the role of enzyme stability. Mol Pharmacol 1999; 56:1063-70. [PMID: 10531414 DOI: 10.1124/mol.56.5.1063] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Inhibitors of the enzyme thymidylate synthase (TS), such as the fluoropyrimidines 5-fluorouracil and 5'-fluoro-2'-deoxyuridine (FdUrd) or the antifolates AG337, ZD1694, and BW1843U89, are widely used in the chemotherapy of cancer, particularly cancer of the colon and rectum. Numerous studies have shown that TS gene amplification, leading to mRNA and enzyme overproduction, is a major mechanism of resistance to these inhibitors. In the present work, we have isolated and characterized FdUrd-resistant derivatives of several human colon tumor cell lines. Although gene amplification was commonly observed, the increases in mRNA and enzyme were strikingly discordant. In one drug-resistant line, a deficiency of enzyme relative to mRNA was shown to be caused by expression of a metabolically unstable TS molecule. The reduced half-life of TS in this line was caused by a Pro-to-Leu substitution at residue 303 of the TS polypeptide. The mutant enzyme conferred resistance to FdUrd as well as antifolates in transfected cells. In another FdUrd-resistant line, which had an excess of enzyme relative to mRNA, the TS molecule was more stable than in the parent line. However, no amino acid substitutions were detected in the TS polypeptide from this line, which suggests that the stabilization must be caused by changes in one or more cellular factors that regulate TS degradation. The results indicate that changes in the stability of the TS polypeptide accompany, and even contribute to, acquired resistance to TS inhibitors in colon tumor cells.
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Affiliation(s)
- M E Kitchens
- Department of Biological Sciences, University of South Carolina, Columbia 29208, USA
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41
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Gruner BA, Weitman SD. The folate receptor as a potential therapeutic anticancer target. Invest New Drugs 1999; 16:205-19. [PMID: 10360600 DOI: 10.1023/a:1006147932159] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- B A Gruner
- Department of Pediatrics, University of Texas Health Science Center, San Antonio 78284-7810, USA
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42
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Rao KN, Venkatachalam SR. Dihydrofolate reductase and cell growth activity inhibition by the beta-carboline-benzoquinolizidine plant alkaloid deoxytubulosine from Alangium lamarckii: its potential as an antimicrobial and anticancer agent. Bioorg Med Chem 1999; 7:1105-10. [PMID: 10428380 DOI: 10.1016/s0968-0896(98)00262-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Beta-carboline-benzoquinolizidine plant alkaloid deoxytubulosine (DTB) was evaluated and assessed for the first time for its biochemical and biological activity employing the biomarker dihydrofolate reductase (DHFR) (5,6,7,8-tetrahydrofolate: NADP+ oxidoreductase, EC 1.5.1.3) as the probe enzyme, a key target in cancer chemotherapy. DHFR, employed in the present investigations was purified from Lactobacillus leichmannii. DTB, isolated from the Indian medicinal plant Alangium lamarckii was demonstrated to exhibit potent cytotoxicity. The alkaloid potently inhibited the cell growth of L. leichmannii and the cellular enzyme activity of DHFR (IC50=40 and 30 microM for the cell growth and enzyme inhibitions, respectively). DTB concentrations >75 microM resulted in a total loss of the DHFR activity, thus suggesting that the beta-carboline-benzoquinolizidine plant alkaloid is a promising potential antitumor agent. Our results are also suggestive of its potential antimicrobial activity. DTB binding to DHFR appears to be slow and reversible. Inhibition kinetics revealed that DHFR has a Ki value of 5x10(-6) M for DTB and that the enzyme inhibition is a simple linear 'non-competitive' type.
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Affiliation(s)
- K N Rao
- Radiation Biology & Biochemistry Division, Bhabha Atomic Research Centre, Bombay, India.
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43
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Kitchens ME, Forsthoefel AM, Rafique Z, Spencer HT, Berger FG. Ligand-mediated induction of thymidylate synthase occurs by enzyme stabilization. Implications for autoregulation of translation. J Biol Chem 1999; 274:12544-7. [PMID: 10212232 DOI: 10.1074/jbc.274.18.12544] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Thymidylate synthase (TS) is indispensable in the de novo synthesis of dTMP. As such, it has been an important target at which anti-neoplastic drugs are directed. The fluoropyrimidines 5-fluorouracil and 5-fluoro-2'-deoxyuridine are cytotoxic as a consequence of inhibition of TS by the metabolite 5-fluoro-2'-deoxyuridine 5'-monophosphate (FdUMP). This inhibition occurs through formation of a stable ternary complex among the enzyme, the nucleotide analog, and the co-substrate N5, N10-methylenetetrahydrofolate. Numerous studies have shown that cellular concentrations of TS undergo about a 2-4-fold induction following treatment with TS inhibitors. An extensive body of in vitro studies has led to the proposal that this induction occurs because of relief of the translational repression brought on by the binding of TS to its own mRNA. In the current study, we have tested several predictions of this autoregulatory translation model. In contrast to expectations, we find that fluoropyrimidines do not cause a change in the extent of ribosome binding to TS mRNA. Furthermore, mutations within the mRNA that abolish its ability to bind TS have no effect on the induction. Finally, enzyme turnover measurements show that the induction is associated with an increase in the stability of the TS polypeptide. Our results, in total, indicate that enzyme stabilization, rather than translational derepression, is the primary mechanism of TS induction by fluoropyrimidines and call into question the general applicability of the autoregulatory translation model.
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Affiliation(s)
- M E Kitchens
- Department of Biological Sciences, University of South Carolina
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44
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Sotelo-Mundo RR, Ciesla J, Dzik JM, Rode W, Maley F, Maley GF, Hardy LW, Montfort WR. Crystal structures of rat thymidylate synthase inhibited by Tomudex, a potent anticancer drug. Biochemistry 1999; 38:1087-94. [PMID: 9894005 DOI: 10.1021/bi981881d] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two crystal structures of rat thymidylate synthase (TS) complexed with dUMP and the anticancer drug Tomudex (ZD1694) have been determined to resolutions of 3.3 and 2.6 A. Tomudex is one of several new antifolates targeted to TS and the first to be approved for clinical use. The structures represent the first views of any mammalian TS bound to ligands and suggest that the rat protein undergoes a ligand-induced conformational change similar to that of the Escherichia coli protein. Surprisingly, Tomudex does not induce the "closed" conformation in rat TS that is seen on binding to E. coli TS, resulting in inhibitor atoms that differ in position by more than 1.5 A. Several species-specific differences in sequence may be the reason for this. Phe 74 shifts to a new position in the rat complex and is in van der Waals contact with the inhibitor, while in the E. coli protein the equivalent amino acid (His 51) hydrogen bonds to the glutamate portion of the inhibitor. Amino acids Arg 101, Asn 106, and Met 305 make no contacts with the inhibitor in the open conformation, unlike the equivalent residues in the E. coli protein (Thr 78, Trp 83, and Val 262). dUMP binding is similar in both proteins, except that there is no covalent adduct to the active site cysteine (Cys 189) in the rat structures. Two insertions in the rat protein are clearly seen, but the N-termini (residues 1-20) and C-termini (residues 301-307) are disordered in both crystal forms.
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Affiliation(s)
- R R Sotelo-Mundo
- Department of Biochemistry, University of Arizona, Tucson 85721, USA
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45
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Abstract
It is almost 50 years since antimetabolites were first found to have clinical antitumour activity, with Farber's discovery that aminopterin could cause remission in acute leukaemia. In the following 10 years, methotrexate, 6-mercaptopurine and 5-fluorouracil (5-FU) found their way into clinical practice. Subsequently, cytosine arabinoside was found to have activity in acute leukaemia, but, until recently, other significant developments have involved optimizing the efficacy of existing antimetabolites, including the use of leucovorin with methotrexate or 5-FU. Recently, new antimetabolites have become a fertile area for anti-cancer drug research. Gemcitabine (GEMZAR) has emerged as an important new agent in several tumour types, including pancreatic, non-small-cell lung, bladder, breast and ovarian cancers. Capecitabine is an intriguing new prodrug, offering tumour selectivity and prolonged tumour exposure to 5-FU. More potent thymidylate synthase inhibitors have also emerged; raltitrexed is now commercially available for the treatment of colorectal cancer. Others under development include LY231514, which has other sites of action, hence the acronym MTA (multi-targeted antifolate). A novel target is glycinamide ribonucleotide formyltransferase (GARFT) and LY309887 and AG2034 are undergoing clinical investigation as GARFT inhibitors. A critical element with LY309887 appears to be co-administration of folate. It seems entirely possible that several novel antimetabolites will establish themselves in clinical practice in future for the treatment of solid tumours.
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Affiliation(s)
- S B Kaye
- Cancer Research Campaign Department of Medical Oncology, Beatson Oncology Centre, Western Infirmary, Glasgow, UK
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46
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Narasimha Rao K, Bhattacharya RK, Venkatachalam SR. Thymidylate synthase activity in leukocytes from patients with chronic myelocytic leukemia and acute lymphocytic leukemia and its inhibition by phenanthroindolizidine alkaloids pergularinine and tylophorinidine. Cancer Lett 1998; 128:183-8. [PMID: 9683281 DOI: 10.1016/s0304-3835(98)00061-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Thymidylate synthase (TS) (EC 2.1.1.45) provides precursors for DNA biosynthesis through a de novo pathway and is a key target enzyme for cancer chemotherapy. TS levels of human leukemic leukocytes from patients with chronic myelocytic leukemia (CML) and acute lymphocytic leukemia (ALL) were observed to be highly elevated (66- and 33-fold for CML and ALL, respectively) compared to the usual low level of basal activity in normal healthy controls. In vitro inhibition studies on the human leukemic leukocyte TS with the phenanthroindolizidine alkaloids pergularinine (PGL) and tylophorinidine (TPD) (isolated from the Indian medicinal herb Pergularia pallida) were conducted for the preliminary screening tests for their antitumor activity. The leukemic leukocyte enzyme activity was potently inhibited by PGL and TPD (IC50 = 50 microM) in both types of leukemias. These alkaloids were assessed for biological evaluation for the first time as potential antileukemic agents.
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MESH Headings
- Adolescent
- Adult
- Alkaloids
- Antineoplastic Agents, Phytogenic/pharmacology
- Child
- Child, Preschool
- Enzyme Inhibitors/pharmacology
- Female
- Humans
- Isoquinolines/pharmacology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/blood
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/enzymology
- Leukocytes/drug effects
- Leukocytes/enzymology
- Male
- Middle Aged
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/blood
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/enzymology
- Thymidylate Synthase/antagonists & inhibitors
- Thymidylate Synthase/blood
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Affiliation(s)
- K Narasimha Rao
- Radiation Biology and Biochemistry Division, Bhabha Atomic Research Centre, Bombay, India.
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Gottasová R, Kubíková J, Cipák L. Antibacterial effect of some 2,6-disubstituted 4-anilinoquinazolines. Folia Microbiol (Praha) 1998; 43:679-82. [PMID: 10189231 DOI: 10.1007/bf02816389] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Two synthetic 2,6-disubstituted 4-anilinoquinazolines exerted a significant effect on the G+ bacteria Bacillus subtilis and staphylococcus aureus. None of 12 tested derivatives influenced Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa. Derivatives having the aromatic ring non-substituted or substituted by bromine, the pyrimidine ring by phenyl, morpholine or piperidine and the aniline skeleton non-substituted or substituted by methyl or amino group exerted a considerable antibacterial activity.
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Affiliation(s)
- R Gottasová
- Department of Biochemistry and Microbiology, Faculty of Chemical Technology, Slovak University of Technology, Bratislava, Slovakia
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Montfort WR, Weichsel A. Thymidylate synthase: structure, inhibition, and strained conformations during catalysis. Pharmacol Ther 1997; 76:29-43. [PMID: 9535167 DOI: 10.1016/s0163-7258(97)00099-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Thymidylate synthase (TS) is a long-standing target for chemotherapeutic agents because of its central role in DNA synthesis, and it is also of interest because of its rich mechanistic features. The reaction catalyzed by TS is the methylation of dUMP, with the transferred methyl group provided by the cofactor methylenetetrahydrofolate (CH2THF). Recently, several crystal structure determinations and mechanistic studies have led to a deeper understanding of the TS reaction mechanism, and address the role of conformational change in TS catalysis and inhibition. Included among these structures are complexes of TS bound to substrate dUMP; cofactor CH2THF; the nucleotide analogs 5-fluoro-dUMP, 5-nitro-dUMP and dGMP; and the promising antifolates BW1843, ZD1694, and AG337. From these studies, a picture of TS emerges where ligand-induced conformational changes play key roles in catalysis by straining the thiol adduct that occurs during the reaction; by protecting the highly reactive reaction intermediates; and by providing a means to stabilize a high-energy conformer of the cofactor after initial binding of a low-energy conformer. The best inhibitors of TS also induce and stabilize a conformational change in TS. One inhibitor, BW1843, distorts the active site on binding, and intercalates into a hydrophobic patch between two mobile subdomains in the protein. Also discussed are recent developments in the cell biology and regulation of eukaryotic TS and the use of structure-based drug design in the development of the antifolates currently in clinical trial for the treatment of cancer.
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Affiliation(s)
- W R Montfort
- Department of Biochemistry, University of Arizona, Tucson 85721, USA
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