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Mechanisms, Management and Prevention of Pemetrexed-Related Toxicity. Drug Saf 2021; 44:1271-1281. [PMID: 34741752 DOI: 10.1007/s40264-021-01135-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2021] [Indexed: 12/17/2022]
Abstract
Pemetrexed is a cytostatic antifolate drug and a cornerstone in the treatment of lung cancer. Although generally well tolerated, a substantial part of the patient population experiences dose-limiting or even treatment-limiting toxicities. These include mucositis, skin problems, fatigue, renal toxicity, and neutropenia. Several studies confirmed that pemetrexed pharmacokinetics can serve as a prognostic factor for the development of toxicity, especially for neutropenia. Preventing and managing toxicity of pemetrexed can help to ensure durable treatment. Several evidence-based strategies are already implemented in clinical care. With the introduction of standard vitamin supplementation and dexamethasone, the incidence of hematological toxicity and skin reactions substantially decreased. In the case of high risk for toxicity, granulocyte colony-stimulating factor can be used to prevent severe hematological toxicity. Moreover, high-dose folinic acid can resolve severe pemetrexed-induced toxicity. There are several experimental options to prevent or manage pemetrexed-related toxicity, such as the use of standard folinic acid, hemodialysis, antidotes such as thymidine, hypoxanthine, and glucarpidase, and the use of therapeutic drug monitoring. These strategies still need clinical evaluation before implementation, but could enable treatment with pemetrexed for patients who are at risk for toxicity, such as in renal impairment.
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2
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Vidmar M, Grželj J, Mlinarič-Raščan I, Geršak K, Dolenc MS. Medicines associated with folate-homocysteine-methionine pathway disruption. Arch Toxicol 2018; 93:227-251. [PMID: 30499019 DOI: 10.1007/s00204-018-2364-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 11/20/2018] [Indexed: 12/18/2022]
Abstract
Folate is vital for cell development and growth. It is involved in one-carbon transfer reactions essential for the synthesis of purines and pyrimidines. It also acts in conjunction with cobalamin (vitamin B12) as a fundamental cofactor in the remethylation cycle that converts homocysteine to methionine. A deficiency in folate or vitamin B12 can lead to elevated homocysteine level, which has been identified as an independent risk factor in several health-related conditions. Adequate folate levels are essential in women of childbearing age and in pregnant women, and folate deficiency is associated with several congenital malformations. Low folate levels can be caused by dietary deficiencies, a genetic predisposition or treatment with medicines that affect folate concentration. Women who are pregnant or of child-bearing age commonly use medicines, so it is important to identify the basic biochemical mechanisms by which medicines interfere with the folate-homocysteine-methionine pathway. This review focuses on prescription medicines associated with folate disruption. It also summarizes their undesirable/toxic effects. Recommendations regarding folate supplementation during medical therapy are also reviewed.
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Affiliation(s)
- M Vidmar
- Research Unit, Department of Obstetrics and Gynecology, University Medical Centre Ljubljana, Šlajmarjeva 3, Ljubljana, Slovenia.,University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, Ljubljana, Slovenia
| | - J Grželj
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, Ljubljana, Slovenia.,Krka, d.d., Novo mesto, Šmarješka 6, Novo mesto, Slovenia
| | - I Mlinarič-Raščan
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, Ljubljana, Slovenia
| | - K Geršak
- Research Unit, Department of Obstetrics and Gynecology, University Medical Centre Ljubljana, Šlajmarjeva 3, Ljubljana, Slovenia
| | - M Sollner Dolenc
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, Ljubljana, Slovenia.
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3
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One-carbon metabolism and nucleotide biosynthesis as attractive targets for anticancer therapy. Oncotarget 2017; 8:23955-23977. [PMID: 28177894 PMCID: PMC5410357 DOI: 10.18632/oncotarget.15053] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 12/02/2016] [Indexed: 12/29/2022] Open
Abstract
Cancer-related metabolism has recently emerged as one of the “hallmarks of cancer”. It has several important features, including altered metabolism of glucose and glutamine. Importantly, altered cancer metabolism connects different biochemical pathways into the one fine-tuned metabolic network, which stimulates high proliferation rates and plasticity to malignant cells. Among the keystones of cancer metabolism are one-carbon metabolism and nucleotide biosynthesis, which provide building blocks to anabolic reactions. Accordingly, the importance of these metabolic pathways for anticancer therapy has well been documented by more than fifty years of clinical use of specific metabolic inhibitors – methotrexate and nucleotides analogs. In this review we discuss one-carbon metabolism and nucleotide biosynthesis as common and specific features of many, if not all, tumors. The key enzymes involved in these pathways also represent promising anti-cancer therapeutic targets. We review different aspects of these metabolic pathways including their biochemistry, compartmentalization and expression of the key enzymes and their regulation at different levels. We also discuss the effects of known inhibitors of these pathways as well as the recent data on other enzymes of the same pathways as perspective pharmacological targets.
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Tian C, Wang M, Han Z, Fang F, Zhang Z, Wang X, Liu J. Design, synthesis and biological evaluation of novel 6-substituted pyrrolo [3,2-d] pyrimidine analogues as antifolate antitumor agents. Eur J Med Chem 2017; 138:630-643. [PMID: 28711701 DOI: 10.1016/j.ejmech.2017.07.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 06/30/2017] [Accepted: 07/02/2017] [Indexed: 11/30/2022]
Abstract
A series of novel 6-substituted pyrrolo[3,2-d]pyrimidine analogues (10a, 11a-13a, 15a, 17a, 18a, 27a and 28a) have been designed and synthesized as antifolate antitumor agents. The anti-proliferative activities of these compounds against HL60, A549, H1299, Hela, HCT116 and HT29 tumor cells were evaluated. Most of the compounds exhibited micromolar anti-proliferative potencies. Compound 15a, the most potent one, has GI50 value of 0.73, 1.72, and 8.92 μM against A549, H1299 and HL60 cells, respectively. The cell cycle distribution assay displayed that 15a could increase the accumulation of G2/M-phase cells. 15a showed low potency in induction of apoptosis. However, the inhibition of A549 cell colony formation was observed. These indicated that the tumor cell death relied on the irreversible effect of 15a on clonogenicity and cell proliferation. The identification of targeted pathway of 15a implied that the anti-proliferative potencies of 15a probably act through dual inhibition of thymidylate synthase (TS) and dihydrofolate reductase (DHFR).
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Affiliation(s)
- Chao Tian
- Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Meng Wang
- Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Zifei Han
- Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Fang Fang
- Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Zhili Zhang
- Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Xiaowei Wang
- Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Junyi Liu
- Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing 100191, China.
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5
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Selvakumar B, Elango KP. Synthesis of Non-Glutamate-Type Pyrrolo[2,3-d]Pyrimidines via Direct Aminocarbonylation of Aryl Halides Using Solid Co 2(CO) 8 as a CO Source and Their Antibacterial Activity. JOURNAL OF CHEMICAL RESEARCH 2017. [DOI: 10.3184/174751917x14894997017658] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The synthesis of pyrrolo[2,3-d]pyrimidine derivatives by direct aminocarbonylation was demonstrated using solid Co2(CO)8 as a CO source in an autoclave at elevated temperature by reacting an aryl halide scaffold with a variety of amines. Using this method, 12 non-glutamate-type pyrrolo[2,3-d]pyrimidine analogues were prepared. Some compounds exhibited antibacterial activity against both Gram-positive and Gram-negative bacteria.
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Affiliation(s)
- Balaraman Selvakumar
- Anthem Biosciences Private Limited, Bangalore 560 099, India
- Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram 624 302, India
| | - Kuppanagounder P. Elango
- Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram 624 302, India
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6
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Abstract
The nutrient folate is essential for normal cell growth and development. Enzymes that require folate as a cofactor have been common targets for chemotherapeutic agents. Limited clinical guidance is available regarding optimal levels of dietary or supplemental folate intake during antifolate chemotherapy to meet the goals of minimizing treatment-related toxicity yet preserving treatment effectiveness. Patients with higher folate intake may experience less treatment-related toxicities; however, the concern is that folate may interfere with the effectiveness of the antifolate treatment and possibly support tumor growth. This article will review folate and antifolate metabolism and review the current body of knowledge regarding the interactions between folates and antifolates. Future research in this area should include evaluation of pretreatment folate status and dietary and supplemental folate intake before, during, and after treatment.
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Affiliation(s)
- Kim Robien
- Cancer Prevention Program, Fred Hutchinson Cancer Research Center, PO Box 19024, M4-B402 Seattle, Washington 98109-1024, USA.
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7
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Weber GF. DNA Damaging Drugs. MOLECULAR THERAPIES OF CANCER 2015. [PMCID: PMC7123643 DOI: 10.1007/978-3-319-13278-5_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/29/2022]
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Matherly LH, Wilson MR, Hou Z. The major facilitative folate transporters solute carrier 19A1 and solute carrier 46A1: biology and role in antifolate chemotherapy of cancer. Drug Metab Dispos 2014; 42:632-49. [PMID: 24396145 PMCID: PMC3965896 DOI: 10.1124/dmd.113.055723] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 01/06/2014] [Indexed: 01/19/2023] Open
Abstract
This review summarizes the biology of the major facilitative membrane transporters, the reduced folate carrier (RFC) (Solute Carrier 19A1) and the proton-coupled folate transporter (PCFT) (Solute Carrier 46A1). Folates are essential vitamins, and folate deficiency contributes to a variety of health disorders. RFC is ubiquitously expressed and is the major folate transporter in mammalian cells and tissues. PCFT mediates the intestinal absorption of dietary folates and appears to be important for transport of folates into the central nervous system. Clinically relevant antifolates for cancer, such as methotrexate and pralatrexate, are transported by RFC, and loss of RFC transport is an important mechanism of methotrexate resistance in cancer cell lines and in patients. PCFT is expressed in human tumors, and is active at pH conditions associated with the tumor microenvironment. Pemetrexed is an excellent substrate for both RFC and PCFT. Novel tumor-targeted antifolates related to pemetrexed with selective membrane transport by PCFT over RFC are being developed. In recent years, there have been major advances in understanding the structural and functional properties and the regulation of RFC and PCFT. The molecular bases for methotrexate resistance associated with loss of RFC transport and for hereditary folate malabsorption, attributable to mutant PCFT, were determined. Future studies should continue to translate molecular insights from basic studies of RFC and PCFT biology into new therapeutic strategies for cancer and other diseases.
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Affiliation(s)
- Larry H Matherly
- Department of Oncology (L.H.M., M.R.W., Z.H.) and Department of Pharmacology (L.H.M.), Wayne State University School of Medicine, Detroit, Michigan; and Molecular Therapeutics Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan (L.H.M., Z.H.)
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Connelly S, DeMartino JK, Boger DL, Wilson IA. Biological and structural evaluation of 10R- and 10S-methylthio-DDACTHF reveals a new role for sulfur in inhibition of glycinamide ribonucleotide transformylase. Biochemistry 2013; 52:5133-44. [PMID: 23869564 DOI: 10.1021/bi4005182] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glycinamide ribonucleotide transformylase (GAR Tfase) is a folate-dependent enzyme in the de novo purine biosynthesis pathway, which has long been considered a potential target for development of anti-neoplastic therapeutics. Here we report the biological and X-ray crystallographic evaluations of both independent C10 diastereomers, 10S- and 10R-methylthio-DDACTHF, bound to human GAR Tfase, including the highest-resolution apo GAR Tfase structure to date (1.52 Å). Both diastereomers are potent inhibitors (Ki = 210 nM for 10R, and Ki = 180 nM for 10S) of GAR Tfase and exhibit effective inhibition of human leukemia cell growth (IC₅₀ = 80 and 50 nM, respectively). Their inhibitory activity was surprisingly high, and these lipophilic C10-substituted analogues show distinct advantages over their hydrophilic counterparts, most strikingly in retaining potency in mutant human leukemia cell lines that lack reduced folate carrier protein activity (IC₅₀ = 70 and 60 nM, respectively). Structural characterization reveals a new binding mode for these diastereoisomers, in which the lipophilic thiomethyl groups penetrate deeper into a hydrophobic pocket within the folate-binding site. In silico docking simulations of three other sulfur-containing folate analogues also indicate that this hydrophobic cleft represents a favorable region for binding lipophilic substituents. Overall, these results suggest sulfur and its substitutions play an important role in not only the binding of anti-folates to GAR Tfase but also the selectivity and cellular activity (growth inhibition), thereby presenting new possibilities for the future design of potent and selective anti-folate drugs that target GAR Tfase.
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Affiliation(s)
- Stephen Connelly
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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Desmoulin SK, Hou Z, Gangjee A, Matherly LH. The human proton-coupled folate transporter: Biology and therapeutic applications to cancer. Cancer Biol Ther 2012; 13:1355-73. [PMID: 22954694 PMCID: PMC3542225 DOI: 10.4161/cbt.22020] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
This review summarizes the biology of the proton-coupled folate transporter (PCFT). PCFT was identified in 2006 as the primary transporter for intestinal absorption of dietary folates, as mutations in PCFT are causal in hereditary folate malabsorption (HFM) syndrome. Since 2006, there have been major advances in understanding the mechanistic roles of critical amino acids and/or domains in the PCFT protein, many of which were identified as mutated in HFM patients, and in characterizing transcriptional control of the human PCFT gene. With the recognition that PCFT is abundantly expressed in human tumors and is active at pHs characterizing the tumor microenvironment, attention turned to exploiting PCFT for delivering novel cytotoxic antifolates for solid tumors. The finding that pemetrexed is an excellent PCFT substrate explains its demonstrated clinical efficacy for mesothelioma and non-small cell lung cancer, and prompted development of more PCFT-selective tumor-targeted 6-substituted pyrrolo[2,3-d]pyrimidine antifolates that derive their cytotoxic effects by targeting de novo purine nucleotide biosynthesis.
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Affiliation(s)
- Sita Kugel Desmoulin
- Cancer Biology Graduate Program in Cancer Biology, Department of Oncology, Wayne State University School of Medicine; Detroit, MI USA
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Gonen N, Assaraf YG. Antifolates in cancer therapy: Structure, activity and mechanisms of drug resistance. Drug Resist Updat 2012; 15:183-210. [DOI: 10.1016/j.drup.2012.07.002] [Citation(s) in RCA: 269] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Revised: 06/25/2012] [Accepted: 07/11/2012] [Indexed: 01/19/2023]
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12
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Desmoulin SK, Wang L, Polin L, White K, Kushner J, Stout M, Hou Z, Cherian C, Gangjee A, Matherly LH. Functional loss of the reduced folate carrier enhances the antitumor activities of novel antifolates with selective uptake by the proton-coupled folate transporter. Mol Pharmacol 2012; 82:591-600. [PMID: 22740639 DOI: 10.1124/mol.112.079004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Uptake of 6-substituted pyrrolo[2,3-d]pyrimidine thienoyl antifolates with four or three bridge carbons [compound 1 (C1) and compound 2 (C2), respectively] into solid tumors by the proton-coupled folate transporter (PCFT) represents a novel therapeutic strategy that harnesses the acidic tumor microenvironment. Although these compounds are not substrates for the reduced folate carrier (RFC), the major facilitative folate transporter, RFC expression may alter drug efficacies by affecting cellular tetrahydrofolate (THF) cofactor pools that can compete for polyglutamylation and/or binding to intracellular enzyme targets. Human tumor cells including wild-type (WT) and R5 (RFC-null) HeLa cells express high levels of PCFT protein. C1 and C2 inhibited proliferation of R5 cells 3 to 4 times more potently than WT cells or R5 cells transfected with RFC. Transport of C1 and C2 was virtually identical between WT and R5 cells, establishing that differences in drug sensitivities between sublines were independent of PCFT transport. Steady-state intracellular [³H]THF cofactors derived from [³H]5-formyl-THF were depleted in R5 cells compared with those in WT cells, an effect exacerbated by C1 and C2. Whereas C1 and C2 polyglutamates accumulated to similar levels in WT and R5 cells, there were differences in polyglutamyl distributions in favor of the longest chain length forms. In severe combined immunodeficient mice, the antitumor efficacies of C1 and C2 were greater toward subcutaneous R5 tumors than toward WT tumors, confirming the collateral drug sensitivities observed in vitro. Thus, solid tumor-targeted antifolates with PCFT-selective cellular uptake should have enhanced activities toward tumors lacking RFC function, reflecting contraction of THF cofactor pools.
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Affiliation(s)
- Sita Kugel Desmoulin
- Graduate Program in Cancer Biology and Department of Oncology, Wayne State University School of Medicine, Detroit, Michigan, USA
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Chattopadhyay S, Tamari R, Min SH, Zhao R, Tsai E, Goldman ID. Commentary: a case for minimizing folate supplementation in clinical regimens with pemetrexed based on the marked sensitivity of the drug to folate availability. Oncologist 2008; 12:808-15. [PMID: 17673612 DOI: 10.1634/theoncologist.12-7-808] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Pemetrexed is a novel antifolate recently approved for the treatment of pleural mesothelioma and non-small cell lung cancer. In clinical regimens, pemetrexed is administered in conjunction with folic acid to minimize toxicity. However, excessive folate supplementation may also diminish the activity of this agent. The current study demonstrates, in several human solid tumor cell lines, that when extracellular 5-formyltetrahydrofolate levels are increased in vitro, within the range of normal human blood levels, there is a substantial decrease in pemetrexed activity upon continuous exposure to the drug. This was accompanied by a comparable lower level of trimetrexate activity consistent with an expansion of tumor cell folate pools. Likewise, when cells were exposed to pemetrexed with a schedule that simulates in vivo pharmacokinetics, there was markedly less cell killing with higher extracellular folate levels. Data are provided to indicate that 5-formyltetrahydrofolate is an acceptable surrogate for 5-methyltetrahydrofolate, the major blood folate, for this type of in vitro study. These observations and other reports suggest that, in view of the rise in serum folate and fall in serum homocysteine that has accompanied folic acid supplementation of food in the U.S., the addition of folic acid to regimens with pemetrexed should be limited to the lowest recommended level that provides optimal protection from pemetrexed toxicity.
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Affiliation(s)
- Shrikanta Chattopadhyay
- Department of Medicine, The Albert Einstein College of Medicine Cancer Center, Bronx, NY 10461, USA
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Takimoto CH, Hammond-Thelin LA, Latz JE, Forero L, Beeram M, Forouzesh B, de Bono J, Tolcher AW, Patnaik A, Monroe P, Wood L, Schneck KB, Clark R, Rowinsky EK. Phase I and Pharmacokinetic Study of Pemetrexed with High-Dose Folic Acid Supplementation or Multivitamin Supplementation in Patients with Locally Advanced or Metastatic Cancer. Clin Cancer Res 2007; 13:2675-83. [PMID: 17473199 DOI: 10.1158/1078-0432.ccr-06-2393] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE This phase I study evaluated the effect of folate supplementation on the toxicity, tolerability, and pharmacokinetics of pemetrexed in patients with locally advanced or metastatic cancer. It also examined two different types of vitamin supplementation and whether the extent of prior myelosuppressive therapy affected pemetrexed tolerability. PATIENTS AND METHODS Patients received a 10-min infusion of 600 to 14,00 mg/m(2) pemetrexed every 3 weeks. Patients were stratified into cohorts by pretreatment status [lightly pretreated (LPT) or heavily pretreated (HPT)] and were supplemented with intermittent high-dose folic acid (HDFA) or with continuous daily multivitamins (MVI) containing nutritional doses of folic acid. Pemetrexed plasma pharmacokinetics were evaluated for cycle 1. RESULTS Sixty-two HDFA patients (28 HPT and 34 LPT) were treated with 204 cycles of pemetrexed, and 43 MVI patients (20 HPT and 23 LPT) were treated with 182 cycles. Hematologic dose-limiting toxicities included grade 4 neutropenia (5 of 105 patients), grade 4 thrombocytopenia (4 of 105 patients), and febrile neutropenia (3 of 105 patients). Nonhematologic toxicities included fatigue, vomiting, diarrhea, and nausea. Pemetrexed doses of 800 and 1,050 mg/m(2) were well tolerated when administered with vitamin supplementation to HPT and LPT patients, respectively. There were no clinically relevant differences in toxicities or pemetrexed pharmacokinetics for LPT versus HPT patients or for patients receiving HDFA versus daily MVI supplementation. CONCLUSIONS The pemetrexed doses tolerated in this study with vitamin supplementation were significantly higher than those tolerated in earlier studies without supplementation, and toxicities were independent of the type of vitamin supplementation or prior myelosuppressive treatment. The recommended dose of pemetrexed is 1,050 mg/m(2) in LPT patients and 800 mg/m(2) in HPT patients, irrespective of the type of vitamin supplementation.
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Affiliation(s)
- Chris H Takimoto
- Institute for Drug Development at the Cancer Therapy and Research Center and University of Texas Health Science Center, San Antonio, Texas 78245-3217, USA.
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Robien K, Schubert MM, Yasui Y, Martin P, Storb R, Potter JD, Ulrich CM. Folic acid supplementation during methotrexate immunosuppression is not associated with early toxicity, risk of acute graft-versus-host disease or relapse following hematopoietic transplantation. Bone Marrow Transplant 2006; 37:687-92. [PMID: 16501595 DOI: 10.1038/sj.bmt.1705303] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Methotrexate (MTX) is used as an immunosuppressive agent for acute graft-versus-host disease (GVHD) prophylaxis following hematopoietic cell transplantation (HCT). Concerns that folate intake may impair MTX effectiveness or selectively rescue leukemic cells have led to variations in clinical practice regarding supplemental folic acid during MTX administration. A retrospective, observational study was undertaken to determine the association between folic acid intake (days 0-18 post transplant) and MTX toxicity and efficacy following HCT. The study population consisted of 311 adult patients who received a myeloablative HCT for chronic myelogenous leukemia, all four scheduled doses of MTX, and did not require leucovorin rescue. Multiple linear regression models were used to assess the relationships between folic acid intake (days 0-18 post-HCT) and oral mucositis index (OMI) scores, time to engraftment and risk of detectable acute GVHD. No statistically significant differences in mean OMI scores, time to engraftment, risk of acute GVHD, days to acute GVHD, risk of relapse or survival were observed when comparing patients taking, on average, <400 (14%), 400 (58%) or >400 microg (28%) folic acid per day. Our results suggest that concurrent folic acid supplementation does not change MTX effectiveness or toxicity in this patient population.
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Affiliation(s)
- K Robien
- Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
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16
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Xu L, Li C, Olson AJ, Wilson IA. Crystal Structure of Avian Aminoimidazole-4-carboxamide Ribonucleotide Transformylase in Complex with a Novel Non-folate Inhibitor Identified by Virtual Ligand Screening. J Biol Chem 2004; 279:50555-65. [PMID: 15355974 DOI: 10.1074/jbc.m406801200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aminoimidazole-4-carboxamide ribonucleotide transformylase (AICAR Tfase), one of the two folate-dependent enzymes in the de novo purine biosynthesis pathway, is a promising target for anti-neoplastic chemotherapy. Although classic antifolates, such as methotrexate, have been developed as anticancer agents, their general toxicity and drug resistance are major issues associated with their clinical use and future development. Identification of inhibitors with novel scaffolds could be an attractive alternative. We present here the crystal structure of avian AICAR Tfase complexed with the first non-folate based inhibitor identified through virtual ligand screening of the National Cancer Institute Diversity Set. The inhibitor 326203-A (2-[5-hydroxy-3-methyl-1-(2-methyl-4-sulfophenyl)-1H-pyrazol-4-ylazo]-4-sulfo-benzoic acid) displayed competitive inhibition against the natural cofactor, 10-formyl-tetrahydrofolate, with a K(i) of 7.1 mum. The crystal structure of AICAR Tfase with 326203-A at 1.8 A resolution revealed a unique binding mode compared with antifolate inhibitors. The inhibitor also accessed an additional binding pocket that is not occupied by antifolates. The sulfonate group of 326203-A appears to form the dominant interaction of the inhibitor with the proposed oxyanion hole through interaction with a helix dipole and Lys(267). An aromatic interaction with Phe(316) also likely contributes to favorable binding. Based on these structural insights, several inhibitors with improved potency were subsequently identified in the National Cancer Institute Compound Library and the Available Chemical Directory by similarity search and molecular modeling methods. These results provide further support for our combined virtual ligand screening rational design approach for the discovery of novel, non-folate-based inhibitors of AICAR Tfase.
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Affiliation(s)
- Lan Xu
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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17
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Kut V, Patel JD, Argiris A. Pemetrexed: a novel antifolate agent enters clinical practice. Expert Rev Anticancer Ther 2004; 4:511-22. [PMID: 15270656 DOI: 10.1586/14737140.4.4.511] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Pemetrexed (Alimta, Eli Lilly) is a multitargeted antifolate that inhibits at least three enzymes in the nucleic acid synthetic pathways. The US Food and Drug Administration recently approved pemetrexed, in combination with cisplatin, for the first-line treatment of advanced malignant pleural mesothelioma. Moreover, pemetrexed was recently shown to be as efficacious as docetaxel (Taxotere, Aventis) in the second-line treatment of non-small cell lung cancer, and its toxicity profile was preferable. The main toxicity seen with pemetrexed is myelosuppression, which is considerably reduced by coadministration of folic acid and vitamin B12. Multiple Phase II clinical trials have demonstrated that pemetrexed has promising single-agent activity in many other solid tumors, including head and neck, breast and colorectal cancers. Combination regimens consisting of pemetrexed and other chemotherapeutics or novel molecular-targeted agents are currently under investigation. Future studies will better define and likely expand the role of pemetrexed for the treatment of cancer.
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Affiliation(s)
- Victoria Kut
- Department of Medicine, Division of Hematology/Oncology, The Feinberg School of Medicine, Robert H Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
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McClish DK, Roberts JD. Phase I studies of weekly administration of cytotoxic agents: implications of a mathematical model. Invest New Drugs 2004; 21:299-308. [PMID: 14578680 DOI: 10.1023/a:1025464510639] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Certain toxic effects of cytotoxic anticancer agents typically evolve over weeks. When such agents are administered weekly, these effects are cumulative. With such schedules, good medical practice mandates dose modifications with mild or moderate toxicity in order to avoid progression to serious or life-threatening toxicity. These modifications lead to differences between scheduled and delivered doses. Phase I studies are designed to identify the maximum tolerated dose for a given schedule. Yet neither standard phase I study designs nor the theoretical literature acknowledge the existence or incorporate the impact of dose modifications upon phase I study outcomes. Our purpose was to better understand the impact of dose reductions/omissions upon outcomes of phase I studies of weekly administration of cytotoxic agents. We created a mathematical model in which toxicity was represented as a power function of dose in order to represent extremes of behavior observed with actual cytotoxic agents in the clinic. We used the model to simulate dosing and toxicity experiences across a wide range of doses. From these simulations we identified "best doses" according to a variety of traditional and novel criteria. We find the concept of maximum tolerated dose inadequate for the determination of best doses. We also suggest a strategy for a new phase I study design which can be used to estimate the "best dose" corresponding to a specified delivery rate. In summary, identification of best doses requires attention, not only to dose limiting toxic events, but also to delivered dose rates and schedule adherence.
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Affiliation(s)
- Donna K McClish
- Department of Biostatistics, Department of Internal Medicine, Division of Quality Health Care, and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA
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Abstract
The antifolates were the first class of antimetabolites to enter the clinics more than 50 years ago. Over the following decades, a full understanding of their mechanisms of action and chemotherapeutic potential evolved along with the mechanisms by which cells develop resistance to these drugs. These principals served as a basis for the subsequent exploration and understanding of the mechanisms of resistance to a variety of diverse antineoplastics with different cellular targets. This section describes the bases for intrinsic and acquired antifolate resistance within the context of the current understanding of the mechanisms of actions and cytotoxic determinants of these agents. This encompasses impaired drug transport into cells, augmented drug export, impaired activation of antifolates through polyglutamylation, augmented hydrolysis of antifolate polyglutamates, increased expression and mutation of target enzymes, and the augmentation of cellular tetrahydrofolate-cofactor pools in cells. This chapter also describes how these insights are being utilized to develop gene therapy approaches to protect normal bone marrow progenitor cells as a strategy to improve the efficacy of bone marrow transplantation. Finally, clinical studies are reviewed that correlate the cellular pharmacology of methotrexate with the clinical outcome in children with neoplastic diseases treated with this antifolate.
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Affiliation(s)
- Rongbao Zhao
- Departments of Medicine and Molecular Pharmacology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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Marsilje TH, Hedrick MP, Desharnais J, Tavassoli A, Zhang Y, Wilson IA, Benkovic SJ, Boger DL. Design, synthesis, and biological evaluation of simplified alpha-keto heterocycle, trifluoromethyl ketone, and formyl substituted folate analogues as potential inhibitors of GAR transformylase and AICAR transformylase. Bioorg Med Chem 2003; 11:4487-501. [PMID: 13129585 DOI: 10.1016/s0968-0896(03)00456-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of simplified alpha-keto heterocycle, trifluoromethyl ketone, and formyl substituted folate analogues lacking the benzoylglutamate subunit were prepared and examined as potential inhibitors of glycinamide ribonucleotide transformylase (GAR Tfase) and aminoimidazole carboxamide transformylase (AICAR Tfase).
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Affiliation(s)
- Thomas H Marsilje
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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Bronder JL, Moran RG. A defect in the p53 response pathway induced by de novo purine synthesis inhibition. J Biol Chem 2003; 278:48861-71. [PMID: 14517211 DOI: 10.1074/jbc.m304844200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
p53 is believed to sense cellular ribonucleotide depletion in the absence of DNA strand breaks and to respond by imposition of a p21-dependent G1 cell cycle arrest. We now report that the p53-dependent G1 checkpoint is blocked in human carcinoma cell lines after inhibition of de novo purine synthesis by folate analogs inhibitory to glycinamide ribonucleotide formyltransferase (GART). p53 accumulated in HCT116, MCF7, or A549 carcinoma cells upon GART inhibition, but, surprisingly, transcription of several p53 targets, including p21cip1/waf1, was impaired. The mechanism of this defect was examined. The p53 accumulating in these cells was nuclear but was not phosphorylated at serines 6, 15, and 20, nor was it acetylated at lysines 373 or 382. The DDATHF-stabilized p53 bound to the p21 promoter in vitro and in vivo but did not activate histone acetylation over the p53 binding sites in the p21 promoter that is an integral part of the transcriptional response mediated by the DNA damage pathway. We concluded that the robust initial response of the p53 pathway to GART inhibitors is not transcriptionally propagated to target genes due to a defect in p53 post-translational modifications and a failure to open chromatin structure despite promoter binding of this unmodified p53.
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Affiliation(s)
- Julie L Bronder
- Department of Pharmacology and Toxicology and The Massey Cancer Center, Medical College of Virginia Campus of Virginia Commonwealth University, Richmond, Virginia 23298, USA
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Abstract
Antimetabolites are active chemotherapeutic agents for many solid tumor and hematologic malignancies. Folate antagonists, purine analogues, and pyrimidine analogues are the three main categories of antimetabolites. Methotrexate, the most studied folate antagonist, is effective in many malignancies. Methotrexate inhibits dihydrofolate reductase, which leads to accumulation of polyglutamated folates, causing further inhibition of thymidylate synthase and glycinamide ribonucleotide formyltransferase. Subsequently, the lack of reduced folate substrates impairs synthesis of purine nucleotides, thymidylate, and certain amino acids, which can lead to cell death. However, methotrexate resistance develops through several mechanisms, including decreased folate carrier-mediated membrane transport, dihydrofolate reductase gene amplification, specific transcription-translational modifications, and downregulation of intracellular methotrexate polyglutamation. Antifolate drug development has focused on agents designed to overcome different aspects of methotrexate resistance. This article reviews the enzymatic targets for antifolates, describes the known mechanisms of antifolate resistance, and summarizes the current development of novel antifolate agents. Discussed specifically are trimetrexate, edatrexate, raltitrexed, pemetrexed, ZD9331, lometrexol, LY309887, GW1843, OSI-7904(L), and nolatrexed, all of which have unique clinical pharmacology and are in various stages of development. The toxicity of antifolates has been sporadic and difficult to predict clinically. Supplementation with folic acid and vitamin B(12) has been shown to reduce the toxicity of pemetrexed without affecting efficacy and has increased the therapeutic index for this novel agent.
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Affiliation(s)
- W Thomas Purcell
- The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University, Bunting-Blaustein Cancer Research Building, 1650 Orleans Street, Room G92, Baltimore, MD 21231-1000, USA.
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Ford HER, Cunningham D. TS Inhibitors and Antifolates. COLORECTAL CANCER 2002. [DOI: 10.1007/978-1-59259-160-2_30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Zhao R, Gao F, Goldman ID. Marked suppression of the activity of some, but not all, antifolate compounds by augmentation of folate cofactor pools within tumor cells. Biochem Pharmacol 2001; 61:857-65. [PMID: 11274972 DOI: 10.1016/s0006-2952(01)00532-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Folates have been co-administered with some antifolates to diminish host toxicity; however, the extent to which this will reduce antitumor activity is not known. To further clarify this issue, studies were undertaken to characterize and quantitate the impact of alterations in intracellular folate levels on the activities of a variety of antifolates in L1210 murine leukemia cells. Intracellular folate cofactor levels increased almost in proportion to the increase in extracellular 5-formyltetrahydrofolate (5-CHO-THF) over a concentration range that encompassed physiological levels of 5-methyltetrahydrofolate. This resulted in a spectrum of increases in the ic50 values of antifolates upon continuous exposure to drugs [Lometrexol (DDATHF) (70x) > trimetrexate (TMQ) (30x), multitargeted antifolate, LY231514 (ALIMTA) (30x) > Raltitrexed, Tomudex (ZD1694) (10x), 6R-2',5'-thienyl-5,10-dideazatetrahydrofolic acid (LY309887) (10x) > methotrexate (MTX) (6x) > (2S)-2-[o-fluoro-p-[N-(2,7-dimethyl-4-oxo-3,4-dihydroquinazolin-6-ylmethyl)-N-(prop-2-ynyl)amino]benzamido]-4-(tetrazol-5-yl) butyric acid (ZD9331) (3x), N(alpha)-(4-amino-4-deoxypteroyl)-N(delta)-hemiphthaloyl-l-ornithine (PT523) (3x)]. Upon a 4-hr pulse exposure to drug, the ic50 values for DDATHF and ALIMTA were increased > 180- and 5-fold, respectively, with only a 2.5-fold increase in the extracellular 5-CHO-THF level within the physiological range. The reductions in drug sensitivities could be attributed to decreases in accumulation of polyglutamate derivatives of ALIMTA and DDATHF. Hence, in these studies, natural folates diminished the activity of agents that undergo polyglutamation by suppression of the formation of these active congeners at the level of folylpolyglutamate synthetase. For inhibitors of dihydrofolate reductase, the suppressive effect of endogenous folates appears to be due to competition between the antifolate and dihydrofolate at the level of the target enzyme. These data should be carefully considered in the design of regimens with antifolates, which incorporate co-administration of folates.
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Affiliation(s)
- R Zhao
- Department of Medicine, and The Albert Einstein Comprehensive Cancer Center, Albert Einstein College of Medicine, Chanin 2, 1300 Morris Park Ave., Bronx, NY10461, USA
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