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Viruses May 2023During the COVID-19 pandemic, drug repurposing represented an effective strategy to obtain quick answers to medical emergencies. Based on previous data on methotrexate...
During the COVID-19 pandemic, drug repurposing represented an effective strategy to obtain quick answers to medical emergencies. Based on previous data on methotrexate (MTX), we evaluated the anti-viral activity of several DHFR inhibitors in two cell lines. We observed that this class of compounds showed a significant influence on the virus-induced cytopathic effect (CPE) partly attributed to the intrinsic anti-metabolic activity of these drugs, but also to a specific anti-viral function. To elucidate the molecular mechanisms, we took advantage of our EXSCALATE platform for in-silico molecular modelling and further validated the influence of these inhibitors on nsp13 and viral entry. Interestingly, pralatrexate and trimetrexate showed superior effects in counteracting the viral infection compared to other DHFR inhibitors. Our results indicate that their higher activity is due to their polypharmacological and pleiotropic profile. These compounds can thus potentially give a clinical advantage in the management of SARS-CoV-2 infection in patients already treated with this class of drugs.
Topics: Humans; SARS-CoV-2; COVID-19; Pandemics; Molecular Docking Simulation; Antiviral Agents; Drug Repositioning
PubMed: 37243214
DOI: 10.3390/v15051128 -
International Journal of Antimicrobial... Aug 2015Streptococcus mutans is a major aetiological agent of dental caries. Formation of biofilms is a key virulence factor of S. mutans. Drugs that inhibit S. mutans biofilms...
Streptococcus mutans is a major aetiological agent of dental caries. Formation of biofilms is a key virulence factor of S. mutans. Drugs that inhibit S. mutans biofilms may have therapeutic potential. Dihydrofolate reductase (DHFR) plays a critical role in regulating the metabolism of folate. DHFR inhibitors are thus potent drugs and have been explored as anticancer and antimicrobial agents. In this study, a library of analogues based on a DHFR inhibitor, trimetrexate (TMQ), an FDA-approved drug, was screened and three new analogues that selectively inhibited S. mutans were identified. The most potent inhibitor had a 50% inhibitory concentration (IC50) of 454.0±10.2nM for the biofilm and 8.7±1.9nM for DHFR of S. mutans. In contrast, the IC50 of this compound for human DHFR was ca. 1000nM, a >100-fold decrease in its potency, demonstrating the high selectivity of the analogue. An analogue that exhibited the least potency for the S. mutans biofilm also had the lowest activity towards inhibiting S. mutans DHFR, further indicating that inhibition of biofilms is related to reduced DHFR activity. These data, along with docking of the most potent analogue to the modelled DHFR structure, suggested that the TMQ analogues indeed selectively inhibited S. mutans through targeting DHFR. These potent and selective small molecules are thus promising lead compounds to develop new effective therapeutics to prevent and treat dental caries.
Topics: Anti-Bacterial Agents; Biofilms; Drug Evaluation, Preclinical; Folic Acid Antagonists; Inhibitory Concentration 50; Microbial Sensitivity Tests; Models, Molecular; Molecular Dynamics Simulation; Streptococcus mutans; Tetrahydrofolate Dehydrogenase; Trimetrexate
PubMed: 26022931
DOI: 10.1016/j.ijantimicag.2015.03.015 -
Annals of Oncology : Official Journal... Apr 20025-Fluorouracil (5-FU)-based regimens have not been shown to prolong survival or provide clinical benefit in patients with advanced pancreatic cancer. The purpose of this... (Clinical Trial)
Clinical Trial
BACKGROUND
5-Fluorouracil (5-FU)-based regimens have not been shown to prolong survival or provide clinical benefit in patients with advanced pancreatic cancer. The purpose of this study was to determine the tolerability of protracted venous infusion (PVI) of 5-FU, modulated by a low dose of the synthetic antifolate trimetrexate, in patients with advanced pancreatic cancer.
PATIENTS AND METHODS
Twenty-three chemotherapy-naïve patients were evaluated. Patients were enrolled in four consecutive cohorts in which the weekly dose of trimetrexate was escalated in 10 mg/m2 increments, from 20 to 50 mg/m2. PVI 5-FU was administered at a fixed dose of 225 mg/m2/day. Treatment was administered for 6 successive weeks, every 8 weeks.
RESULTS
Twenty-two patients were assessable. The maximum tolerated dose of trimetrexate was 40 mg/m2. The most common grade 3 and 4 toxicity was diarrhea. There were no treatment-related deaths. Preliminary analysis of activity revealed a response rate of 9%, with 41% of the patients having stable disease for a median duration of 3.8 months. The median survival for the entire group was 6.9 months (range 1-29 months). A clinical benefit response was experienced by 27.2% of patients.
CONCLUSIONS
Low-dose trimetrexate can be safely administered in combination with PVI 5-FU. This treatment is well tolerated and is associated with palliative activity in advanced pancreatic cancer.
Topics: Adult; Aged; Aged, 80 and over; Antimetabolites, Antineoplastic; Antineoplastic Combined Chemotherapy Protocols; Diarrhea; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Combinations; Female; Fluorouracil; Glucuronates; Humans; Infusions, Intravenous; Male; Middle Aged; Palliative Care; Pancreatic Neoplasms; Survival Analysis; Trimetrexate
PubMed: 12056709
DOI: 10.1093/annonc/mdf090 -
Antimicrobial Agents and Chemotherapy Jan 1995Twenty-eight 2,4-diaminopteridines with alkyl and aralkyl groups at the 6- and 7-positions, five 1,3-diamino-7,8,9,10-tetrahydropyrimido [4,5-c]isoquinolines with an...
Twenty-eight 2,4-diaminopteridines with alkyl and aralkyl groups at the 6- and 7-positions, five 1,3-diamino-7,8,9,10-tetrahydropyrimido [4,5-c]isoquinolines with an alkyl, alkylthio, or aryl group at the 6-position, and nine 4,6-diamino-1,2-dihydro-s-triazines with one or two alkyl groups at the 2-position and a substituted phenyl or naphthyl group at the 1-position were evaluated as inhibitors of dihydrofolate reductase enzymes from Pneumocystis carinii, Toxoplasma gondii, and rat liver. Halogen substitution at the 5- or 6-position of 2,4-diaminoquinazoline favored selective binding to the P. carinii enzyme but not the T. gondii enzyme. For example, the 50% inhibitory concentrations of 2,4-diamino-6-chloroquinazoline as an inhibitor of P. carinii, T. gondii, and rat liver dihydrofolate reductase were 3.6, 14 and 29 microM, respectively, corresponding to 12-fold selectivity for the P. carinii enzyme but only marginal selectivity for the T. gondii enzyme. Greater than fivefold selectivity for P. carinii but not T. gondii dihydrofolate reductase was also observed for the 2,4-diaminoquinazolines with 5-methyl, 5-fluoro, 5- and 6-bromo, 6-chloro, and 5-chloro-6-bromo substitution. In contrast, alkyl and aralkyl substitution at the 6- and 7-positions of 2,4-diaminopteridines was found to be a favorable feature for selective inhibition of the T. gondii enzyme and, in two cases, for both enzymes. Nine of the fifty-one compounds tested against P. carinii dihydrofolate reductase and four of the thirty compounds tested against T. gondii dihydrofolate reductase displayed fivefold or greater selectivity for the microbial enzyme versus the rat liver enzyme. The most selective against both enzymes was 2,4-diamino-6,7-bis(cyclohexylmethyl) pteridine, with a selectivity ratio 2 orders of magnitude greater than the value reported for trimetrexate and piritrexim. Since substitution at the 7-position is generally considered to be detrimental to the binding of 2,4-diaminop-teridines and related compounds to mammalian dihydrofolate reductase, the selectivity observed in this study with the 6,7-bis(cyclohexylmethyl) analog may represent a useful approach to enhancing selective inhibition of the enzyme from nonmammalian species.
Topics: Animals; Enzyme Inhibitors; Folic Acid Antagonists; Liver; Pneumocystis; Pteridines; Quinazolines; Rats; Structure-Activity Relationship; Toxoplasma
PubMed: 7695334
DOI: 10.1128/AAC.39.1.79 -
Frontiers in Bioscience (Elite Edition) Jan 2010The design and analysis of drug combination studies continue to be an area requiring further methodological developments. Faessel et al. (1998) studied the joint effects...
The design and analysis of drug combination studies continue to be an area requiring further methodological developments. Faessel et al. (1998) studied the joint effects of the combinations of trimetrexate (TMQ) and the GARFT inhibitor AG2034 to inhibit the growth of HCT-8 human ileocecal adenocarcinoma cells. Their experiments provide a rich data resource to validate the performance of new experimental design and analysis methods for future experiments. In this paper, we first re-analyze the same data with a nonparametric model and briefly review the experimental design used in the original paper. By comparing the analysis results, we found that the fixed ratio design and the usage of the parametric model for estimating the interaction index are based on an assumption not supported by the data. We then show how the efficiency of the experiments would be improved had the maximal power experimental design based on uniform measures been used. The usage of the proposed maximal power experimental design is further supported by simulation studies.
Topics: Cell Line, Tumor; Computer Simulation; Data Interpretation, Statistical; Drug Interactions; Glutamates; Humans; Models, Theoretical; Pyrimidines; Research Design; Statistics, Nonparametric; Trimetrexate
PubMed: 20036876
DOI: 10.2741/e88 -
Bioorganic & Medicinal Chemistry Letters Aug 2019Pneumocystis pneumonia (PCP) caused by Pneumocystis jirovecii (pj) can lead to serious health consequences in patients with an immunocompromised system. Trimethoprim...
Pneumocystis pneumonia (PCP) caused by Pneumocystis jirovecii (pj) can lead to serious health consequences in patients with an immunocompromised system. Trimethoprim (TMP), used as first-line therapy in combination with sulfamethoxazole, is a selective but only moderately potent pj dihydrofolate reductase (pjDHFR) inhibitor, whereas non-clinical pjDHFR inhibitors, such as, piritrexim and trimetrexate are potent but non-selective pjDHFR inhibitors. To meet the clinical needs for a potent and selective pjDHFR inhibitor for PCP treatment, fourteen 6-substituted pyrido[3,2-d]pyrimidines were developed. Comparison of the amino acid residues in the active site of pjDHFR and human DHFR (hDHFR) revealed prominent amino acid differences which could be exploited to structurally design potent and selective pjDHFR inhibitors. Molecular modeling followed by enzyme assays of the compounds revealed 15 as the best compound of the series with an IC of 80 nM and 28-fold selectivity for inhibiting pjDHFR over hDHFR. Compound 15 serves as the lead analog for further structural variations to afford more potent and selective pjDHFR inhibitors.
Topics: Folic Acid Antagonists; Humans; Models, Molecular; Pneumocystis; Pneumocystis carinii; Pyrimidines; Structure-Activity Relationship; Trimethoprim
PubMed: 31176699
DOI: 10.1016/j.bmcl.2019.06.004 -
Frontiers in Bioscience (Elite Edition) Jan 2010The goal of the present report is to compare several published methods of analyzing drug-drug interaction data. The compared methods are the curve-shift analysis,... (Comparative Study)
Comparative Study
The goal of the present report is to compare several published methods of analyzing drug-drug interaction data. The compared methods are the curve-shift analysis, isobologram, combination index, and universal surface response analysis, and the comparison was based on analysis of published cytotoxicity data of combinations of two anti-folate agents. Major findings are as follows. The curve shift analysis enabled the inspection of the experimental data and visual evaluation of the approximate parallelism between the dose response curves. Isobologram analysis provided the range of concentration ratios where maximal synergy was obtained. The combination index analysis readily provided quantitative estimation of the extent of synergy or antagonism. The universal surface response method summarized drug-drug interaction in a single parameter, facilitating comparison of larger arrays of combinations. Only the curve shift analysis and the universal surface response method yielded a statistical estimate of differentiation between synergy, additivity, and antagonism. In summary, curve shift analysis, isobolograms, combination index analysis, and the universal response surface method are useful methods for analyzing drug-drug interaction, and provide complementary information.
Topics: Cell Line, Tumor; Data Interpretation, Statistical; Dose-Response Relationship, Drug; Drug Combinations; Drug Interactions; Drug Synergism; Folic Acid; Glutamates; Humans; Models, Theoretical; Pyrimidines; Trimetrexate
PubMed: 20036874
DOI: 10.2741/e86 -
The Oncologist 2010
Topics: Academic Medical Centers; Drug Discovery; Drug Industry; Editorial Policies; Humans; Periodicals as Topic
PubMed: 20086167
DOI: 10.1634/theoncologist.2009-0338 -
Antimicrobial Agents and Chemotherapy Jun 1998
Review
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Atovaquone; Clindamycin; Dapsone; Eflornithine; Humans; Macrolides; Naphthoquinones; Pentamidine; Pneumocystis; Pneumocystis Infections; Pneumonia, Pneumocystis; Pyrimidines; Trimethoprim, Sulfamethoxazole Drug Combination; Trimetrexate
PubMed: 9624465
DOI: 10.1128/AAC.42.6.1309 -
Antimicrobial Agents and Chemotherapy Sep 2009We have analyzed the activities of the antifolates pyrimethamine (PM), chlorcycloguanil (CCG), WR99210, trimethoprim (TMP), methotrexate (MTX), and trimetrexate (TMX)...
In vitro activity of antifolate and polymorphism in dihydrofolate reductase of Plasmodium falciparum isolates from the Kenyan coast: emergence of parasites with Ile-164-Leu mutation.
We have analyzed the activities of the antifolates pyrimethamine (PM), chlorcycloguanil (CCG), WR99210, trimethoprim (TMP), methotrexate (MTX), and trimetrexate (TMX) against Kenyan Plasmodium falciparum isolates adapted in vitro for long-term culture. We have also assessed the relationship between these drug activities and mutations in dihydrofolate reductase (dhfr), a domain of the gene associated with antifolate resistance. As expected, WR99210 was the most potent drug, with a median 50% inhibitory concentration (IC50) of <0.075 nM, followed by TMX, with a median IC50 of 30 nM. The median IC50 of CCG was 37.80 nM, and that of MTX was 83.60 nM. PM and TMP were the least active drugs, with median IC50s of 733.26 nM and 29,656.04 nM, respectively. We analyzed parasite dhfr genotypes by the PCR-enzyme restriction technique. No wild-type dhfr parasite was found. Twenty-four of 33 parasites were triple mutants (mutations at codons 108, 51, and 59), and only 8/33 were double mutants (mutations at codons 108 and 51 or at codons 108 and 59). IC50s were 2.1-fold (PM) and 3.6-fold (TMP) higher in triple than in double mutants, though these differences were not statistically significant. Interestingly, we have identified a parasite harboring a mutation at codon 164 (Ile-164-Leu) in addition to mutations at codons 108, 51, and 59. This quadruple mutant parasite had the highest TMP IC50 and was in the upper 10th percentile against PM and CCG. We confirmed the presence of this mutation by sequencing. Thus, TMX and MTX are potent against P. falciparum, and quadruple mutants are now emerging in Africa.
Topics: Animals; Antimalarials; Folic Acid Antagonists; Genotype; Inhibitory Concentration 50; Kenya; Methotrexate; Mutation; Plasmodium falciparum; Polymerase Chain Reaction; Polymorphism, Genetic; Proguanil; Pyrimethamine; Tetrahydrofolate Dehydrogenase; Triazines; Trimethoprim; Trimetrexate
PubMed: 19528269
DOI: 10.1128/AAC.00308-09