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1.
Mater Sci Eng C Mater Biol Appl ; 108: 110461, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31924029

RESUMO

A novel bio-responsive co-delivery system based on Poly(DEA)-b-Poly(ABMA-co-OEGMA) (PDPAO, prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization) copolymers was constructed for enhanced cellular internalization and effective combination therapy. Reduction-sensitive 6-mercaptopurine (6MP) based prodrug and pH-sensitive doxorubicin (DOX) based prodrug were grafted onto PDPAO by an azide-alkyne "Click Chemistry" reaction to acquire a pH/reduction-sensitive polymeric prodrug (PDPAO@imine-DOX/cis-6MP), which was able to self-aggregate to form polymeric micelles (M(DOX/6MP)) with an average particle size of 116 ± 2 nm in the water. The resultant micelles could maintain a stable sphere structure and show stability with a small particles' dispersion index in the blood. Importantly, it has been observed that the pH-sensitive surface charge-conversion accompanied pH-triggered DOX release in the biomimetic extracellular acidic environment of tumor tissue and a rapid dual-drug release triggered by pH and GSH in the intracellular environment. The in vitro evaluation of micelles on human cervical cancer (HeLa) and human promyelocytic leukemia (HL-60) cells showed an enhanced cellular uptake because of charge-conversion and exhibited a higher cell-killing performance. Moreover, the graft ratio of DOX and 6MP showed the ability to adjust the cytotoxicity; the micelles with a graft ratio of 2: 1 (M(DOX2/6MP)) displayed the higher cellular inhibition on either HeLa (combination index (CI) = 0.62) or HL-60 (CI = 0.35) cells. Overall, this novel dual-drug-conjugated delivery system might have important potential applications for combination therapy of cancer.


Assuntos
Química Click , Doxorrubicina , Portadores de Fármacos , Mercaptopurina , Neoplasias/tratamento farmacológico , Pró-Fármacos , Preparações de Ação Retardada/síntese química , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacologia , Portadores de Fármacos/síntese química , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Células HL-60 , Células HeLa , Humanos , Mercaptopurina/química , Mercaptopurina/farmacologia , Neoplasias/metabolismo , Neoplasias/patologia , Pró-Fármacos/síntese química , Pró-Fármacos/química , Pró-Fármacos/farmacologia
2.
Inorg Chem ; 58(23): 16154-16170, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31721562

RESUMO

In this study, two new bis-cyclometalated Pt(II) complexes, [Pt(C^N)(S^N)] [S^N = deprotonated 6-mercaptopurine (6-MP) and C^N = deprotonated 2-phenylpyridine (ppy), 2a; C^N = deprotonated benzo[h]quinoline (bhq), 2b], are synthesized by the reaction of [PtR(SMe2)(C^N)] (R = Me or p-MeC6H4) with 1 equiv of 6-mercaptopurine (6-HMP) at room temperature. The complexes are fully characterized using 1H and 13C NMR spectroscopies, electrospray ionization mass spectrometry, and elemental analysis. Biomolecular interaction of complex 2a with human serum albumin (HSA) is studied by fluorescence, UV-vis, and circular dichroism (CD) spectroscopies. The binding constants (Kb) and number of binding sites (n) are evaluated using the Stern-Volmer equation. The intrinsic fluorescence of protein is quenched by a static quenching mechanism, with a binding constant of Kb ∼ 105 reflecting a high affinity of complex 2a for HSA. The thermodynamic parameters (ΔH°, ΔG°, and ΔS°) indicate that the interaction is a spontaneous process and hydrophobic forces play a main role in the reaction. The displacement experiments demonstrate that the reactive binding sites of HSA to complex 2a are mainly located within its hydrophobic cavity in subdomain IIA (site I). Synchronous fluorescence spectra reveal that complex 2a affected the microenvironment of tryptophan-214 residues in subdomain IIA of HSA. In the case of interaction of complex 2b and HSA, because of overlapping of the emission spectra of complex 2b with HSA, chemometric approaches are applied. The results indicate significant interaction between the tryptophan residue of HSA and complex 2b. Moreover, the binding of Pt(II) complexes 2a and 2b causes a reduction of the α-helix content of HSA, as obtained by far-UV CD spectroscopy. The average binding distance (r) between Pt(II) complexes and HSA is obtained by Förster's resonance energy-transfer theory. Also, a molecular docking simulation reveals that π-π-stacking and hydrophobic interactions between these complexes and HSA are significant. Furthermore, the interactions of platinum complexes, 2, with calf-thymus DNA (CT-DNA) are investigated. The UV-vis results and ethidium bromide competitive studies support an intercalative interaction of both Pt(II) complexes with DNA. The new complexes 2 are also screened for anticancer activities. The results show that complexes 2 exhibit significant anticancer activity against the K562 (chronic myelogenous leukemia) cell line.


Assuntos
Antineoplásicos/farmacologia , DNA/efeitos dos fármacos , Mercaptopurina/farmacologia , Compostos Organoplatínicos/farmacologia , Albumina Sérica Humana/efeitos dos fármacos , Antineoplásicos/síntese química , Antineoplásicos/química , Sítios de Ligação/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , DNA/química , Teoria da Densidade Funcional , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Células K562 , Mercaptopurina/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Compostos Organoplatínicos/síntese química , Compostos Organoplatínicos/química , Albumina Sérica Humana/química , Relação Estrutura-Atividade , Termodinâmica
3.
Int J Mol Sci ; 20(17)2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31438649

RESUMO

The transforming growth factor-beta (TGF-ß) plays an important role in pathological fibrosis and cancer transformation. Therefore, the inhibition of the TGF-ß signaling pathway has therapeutic potential in the treatment of cancer. In this study, the binding modes between 47 molecules with a pyrrolotriazine-like backbone structure and transforming growth factor-beta type 1 receptor (TßR1) were simulated by molecular docking using Discovery Studio software, and their structure-activity relationships were analyzed. On the basis of the analysis of the binding modes of ligands in the active site and the structure-activity relationships, 29,254 new compounds were designed for virtual screening. According to the aforementioned analyses and Lipinski's rule of five, five new compounds (CQMU1901-1905) with potential activity were screened through molecular docking. Among them, CQMU1905 is an attractive molecule composed of 5-fluorouracil (5-FU), 6-mercaptopurine (6-MP), and 5-azacytosine. Interestingly, 5-FU, 6-MP, and 5-azacytidine are often used as anti-metabolic agents in cancer treatment. Compared with existing compounds, CQMU1901-1905 can interact with target proteins more effectively and have good potential for modification, making them worthy of further study.


Assuntos
Receptor do Fator de Crescimento Transformador beta Tipo I/antagonistas & inibidores , Citosina/análogos & derivados , Citosina/química , Citosina/farmacologia , Fluoruracila/química , Fluoruracila/farmacologia , Humanos , Mercaptopurina/química , Mercaptopurina/farmacologia , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade
4.
Mol Cancer Ther ; 18(10): 1887-1895, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31358663

RESUMO

Relapse remains a formidable challenge for acute lymphoblastic leukemia (ALL). Recently, recurrent mutations in NT5C2 were identified as a common genomic lesion unique in relapsed ALL and were linked to acquired thiopurine resistance. However, molecular mechanisms by which NT5C2 regulates thiopurine cytotoxicity were incompletely understood. To this end, we sought to comprehensively characterize the biochemical and cellular effects of NT5C2 mutations. Compared with wild-type NT5C2, mutant proteins showed elevated 5'-nucleotidase activity with a stark preference of thiopurine metabolites over endogenous purine nucleotides, suggesting neomorphic effects specific to thiopurine metabolism. Expression of mutant NT5C2 mutations also significantly reduced thiopurine uptake in vitro with concomitant increase in efflux of 6-mercaptopurine (MP) metabolites, plausibly via indirect effects on drug transporter pathways. Finally, intracellular metabolomic profiling revealed significant shifts in nucleotide homeostasis induced by mutant NT5C2 at baseline; MP treatment also resulted in global changes in metabolomic profiles with completely divergent effects in cells with mutant versus wild-type NT5C2. Collectively, our data indicated that NT5C2 mutations alter thiopurine metabolism and cellular disposition, but also influence endogenous nucleotide homeostasis and thiopurine-induced metabolomic response. These complex mechanisms contributed to NT5C2-mediated drug resistance in ALL and pointed to potential opportunities for therapeutic targeting in relapsed ALL.


Assuntos
5'-Nucleotidase/metabolismo , Resistencia a Medicamentos Antineoplásicos , Mercaptopurina/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Linhagem Celular Tumoral , Células HEK293 , Humanos , Cinética , Mercaptopurina/química , Mercaptopurina/farmacologia , Metabolômica , Modelos Biológicos , Mutação/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia
5.
Int J Pharm Compd ; 22(6): 516-526, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30384353

RESUMO

Compounded liquid medication is frequently required in children to allow easy dose adjustment and overcome swallowing difficulties. The objective of this study was to evaluate the stability of oral suspensions compounded with SyrSpend SF PH4 and the commonly used active pharmaceutical ingredients baclofen 2.0 mg/mL, carvedilol 5.0 mg/mL, hydrochlorothiazide 2.0 mg/mL, mercaptopurine 10.0 mg/mL, methadone hydrochloride 10.0 mg/mL, oseltamivir phosphate 6.0 mg/mL, phenobarbital 9.0 mg/mL and 15.0 mg/mL, propranolol hydrochloride 0.5 mg/mL and 5.0 mg/mL, pyrazinamide 100.0 mg/mL, spironolactone 2.0 mg/mL and 2.5 mg/mL, sotalol hydrochloride 5.0 mg/mL, tacrolimus monohydrate 0.5 mg/mL, ursodeoxycholic acid 20.0 mg/mL, and vancomycin hydrochloride 25.0 mg/mL. Suspensions were compounded with raw powders, except for mercaptopurine, pyrazinamide, and sotalol hydrochloride, which were made from commercial tablets. Stability was assessed by measuring the percentage recovery at 0 (baseline), 60 days, and 90 days after compounding for suspensions made with raw powders, which were stored at 2ÅãC to 8ÅãC. The stability of tablets, which were stored at 2ÅãC to 8ÅãC and 20ÅãC to 25ÅãC, was assessed by measuring the percentage recovery at 0 (baseline), 7 days, 14 days, 30 days, 60 days, and 90 days. Active pharmaceutical ingredients quantification was performed by ultraviolet high-performance liquid chromatography via a stability-indicating method. Given the percentage of recovery of the active pharmaceutical ingredients within the suspensions, the beyond-use date of the final products (active pharmaceutical ingredients + vehicle) was at least 90 days for all suspensions in the conditions tested. This suggests that SyrSpend SF PH4 is suitable for compounding active pharmaceutical ingredients from different pharmacological classes.


Assuntos
Baclofeno/química , Carvedilol/química , Hidroclorotiazida/química , Mercaptopurina/química , Metadona/química , Oseltamivir/química , Veículos Farmacêuticos/química , Fenobarbital/química , Propranolol/química , Sotalol/química , Espironolactona/química , Amido/química , Tacrolimo/química , Ácido Ursodesoxicólico/química , Vancomicina/química , Administração Oral , Baclofeno/administração & dosagem , Carvedilol/administração & dosagem , Composição de Medicamentos , Estabilidade de Medicamentos , Hidroclorotiazida/administração & dosagem , Concentração de Íons de Hidrogênio , Mercaptopurina/administração & dosagem , Metadona/administração & dosagem , Oseltamivir/administração & dosagem , Soluções Farmacêuticas , Fenobarbital/administração & dosagem , Propranolol/administração & dosagem , Pirazinamida/administração & dosagem , Sotalol/administração & dosagem , Espironolactona/administração & dosagem , Suspensões , Tacrolimo/administração & dosagem , Temperatura , Fatores de Tempo , Ácido Ursodesoxicólico/administração & dosagem , Vancomicina/administração & dosagem
6.
Mater Sci Eng C Mater Biol Appl ; 92: 599-611, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30184786

RESUMO

The clinical applications of anticancer drugs are restricted due to the incomplete delivery to the cancerous tissue and the numerous drug resistance mechanisms involved in malignant cells. In this regard, stimuli-responsive nanomaterials offer a promising prospect to deal with these concerns. In the present study, ternary responsive hybrid gold/nanogels (Au/NGs) were synthesized as a new nanoplatform to simultaneously carry two anticancer drugs, i.e., doxorubicin (DOX) and 6-mercaptopurine (MP). For this purpose, these drugs were successfully loaded (the loading capacity of 23% and 11%, respectively) into the hybrid Au/NGs by electrostatic interaction (DOX) and AuS bonds (MP). The triggered drug release ability of hybrid Au/NGs was assessed by comparing the environments of simulated physiological and tumor tissue. The incorporation of disulfide bond linkers, pH sensitive, and thermosensitive polymeric segments endowed the NGs with an excellent property in reducing acidic and hyperthermia environments, which greatly facilitates drug release in tumor cells. Intracellular tracking of DOX@MP-Au/NGs confirmed efficient accumulation and cellular uptake of developed NGs and the cytotoxicity studies showed a pronounced tumor inhibition compared with free DOX@MP. It was concluded that the new ternary-responsive NGs have great potential for co-delivery of DOX and MP and can be used in efficient cancer therapy.


Assuntos
Doxorrubicina , Sistemas de Liberação de Medicamentos , Ouro , Mercaptopurina , Nanopartículas/química , Neoplasias/tratamento farmacológico , Polietilenoglicóis , Doxorrubicina/química , Doxorrubicina/farmacologia , Géis , Ouro/química , Ouro/farmacologia , Humanos , Células MCF-7 , Mercaptopurina/química , Mercaptopurina/farmacologia , Neoplasias/metabolismo , Neoplasias/patologia , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia
7.
Mikrochim Acta ; 185(8): 400, 2018 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-30076470

RESUMO

Water-soluble and non-aggregating gold nanoclusters (AuNCs) were obtained by modification of the AuNCs with dithiothreitol (DTT) and then coating them with carboxylated chitosan. This process remarkably enhances the dispersibility of DTT-coated AuNCs in water. The resulting AuNCs, on photoexcitation at 285 nm, display strong red emission with a maximum at 650 nm and a 23% quantum yield. Fluorescence is strongly and selectively suppressed in the presence of 6-mercaptopurine (6-MP). Photoluminescence drops linearly in the 0.1-100 µM 6-MP concentration range, and the detection limit of this assay is 0.1 µM. Other features of the modified AuNCs include a decay time of 8.56 µs, a 365 nm Stokes shift, good colloidal stability, ease of chemical modification, and low toxicity. Conceivably, these NCs may find a range of applications in biological imaging and optical sensing. Graphical abstract Highly fluorescent and water-soluble gold nanoclusters (AuNCs) were obtained by modification of the AuNCs with dithiothreitol (DTT) and then coating them with carboxylated chitosan (CC). The resulting CC/DTT-AuNCs were used for sensitive and selective detection of 6-mercaptopurine.


Assuntos
Quitosana/química , Ditiotreitol/química , Corantes Fluorescentes/química , Ouro/química , Mercaptopurina/análise , Nanoestruturas/química , Água/química , Fluorometria , Imunossupressores/análise , Imunossupressores/química , Limite de Detecção , Mercaptopurina/química , Solubilidade
8.
Clin Biochem ; 54: 100-105, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29425801

RESUMO

BACKGROUND: Identification of patients with thiopurine S-methyltransferase (TPMT) deficiency prior to thiopurine drug therapy has become routine clinical practice worldwide. To measure TPMT activity, traditional radiochemical assays have been replaced by chromatographic methods. METHOD: Inspired by the increasing number of isotope labelled sources that may be of benefit for the TPMT assay, a new LC-MS/MS method for TPMT activity was developed and validated. Isotope labelled d3-S-adenosyl-l-methionine (d3-SAM) was selected for the enzymatic methylation of mercaptopurine during sample incubation; d3-6-methylmercaptopurine (d3-6-MMP) with d2-2, 8-hypoxanthine as the internal standard was quantified to ascertain individual TPMT activity. RESULTS: The validation of the analytical part of this method showed good linearity (coefficient of determination 0.9999 in the range of 1-500 ng/mL) with the intra-and inter-day impression CV% between 7.6% and 9.1% and 3.7% and 9.2%, respectively. Recovery ranged from 94.9% to 112.3%. The specificity of the enzymatic reaction was validated by using 108 clinical check samples. After compared with traditional radiochemical assay and genotype results, all homozygous and heterozygous deficiency clinical checks fitted into the nominal groups, inter-batch and intra-batch impression CV% were between 2.3% and 9.7%. CONCLUSION: With the inclusion of isotope labelled substrate, interfering non-enzymatic methylation no longer results in potential false assignment of abnormal patients. Furthermore, the method can be applied to patients who have already been prescribed thiopurine drugs. This new LC-MS/MS is therefore a favourable clinical routine application to test TPMT activity, as it shows excellent performance in identifying patients with TPMT deficiency.


Assuntos
Espectrometria de Massas/métodos , Mercaptopurina/análogos & derivados , Metiltransferases/análise , Cromatografia Líquida/métodos , Humanos , Mercaptopurina/química , Metiltransferases/química
9.
Talanta ; 176: 667-673, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28917805

RESUMO

In this work, we report on the electrochemical behavior of bioconjugates prepared with gold nanoparticles (AuNP) capped with three different molecular layers (citrate anions, 6-mercaptopurine and ω-mercaptoundecanoic acid) and the protein hemoglobin (Hb). Freshly formed bioconjugates are deposited on a glassy carbon electrode and assayed for electroactivity. A pair of redox peaks with formal potential at -0.37V is obtained, in contrast with the free Hb protein that is inactive on the glassy carbon substrate. The redox response is typical for quasi-reversible processes allowing the determination of the electron transfer rate constant for the three bioconjugates. Additional evidence of the structural integrity of protein upon forming the bioconjugate is obtained by monitoring the electrochemical response of the Hb heme Fe(III)/Fe(II) redox couple as a function of solution pH. Moreover, the Hb forming the protein corona around the AuNPs show good electrocatalytic activity for the reduction of hydrogen peroxide and oxygen. It has been found that only the first layer of Hb surrounding the AuNPs are electroactive, although some part of the second layer also contribute, pointing to the role of the AuNP in the electrochemical response.


Assuntos
Ouro/química , Hemoglobinas/química , Nanopartículas Metálicas/química , Carbono/química , Catálise , Ácido Cítrico/química , Eletroquímica , Eletrodos , Ácidos Graxos/química , Peróxido de Hidrogênio/química , Mercaptopurina/química , Oxigênio/química , Compostos de Sulfidrila/química
10.
J Biomol Struct Dyn ; 36(6): 1369-1401, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28436311

RESUMO

The theoretical studies on DNA with the anticancer drug 6-Mercaptopurine (6-MP) are investigated using theoretical methods to shed light on drug designing. Among the DNA base pairs considered, 6-MP is stacked with GC with the highest interaction energy of -46.19 kcal/mol. Structural parameters revealed that structure of the DNA base pairs is deviated from the planarity of the equilibrium position due to the formation of hydrogen bonds and stacking interactions with 6-MP. These deviations are verified through the systematic comparison between X-H bond contraction and elongation and the associated blue shift and red shift values by both NBO analysis and vibrational analysis. Bent's rule is verified for the C-H bond contraction in the 6-MP interacted base pairs. The AIM results disclose that the higher values of electron density (ρ) and Laplacian of electron density (∇2ρ) indicate the increased overlap between the orbitals that represent the strong interaction and positive values of the total electron density show the closed-shell interaction. The relative sensitivity of the chemical shift values for the DNA base pairs with 6-MP is investigated to confirm the hydrogen bond strength. Molecular dynamics simulation studies of G-quadruplex DNA d(TGGGGT)4 with 6-MP revealed that the incorporation of 6-MP appears to cause local distortions and destabilize the G-quadruplex DNA.


Assuntos
Pareamento de Bases/efeitos dos fármacos , DNA/química , Quadruplex G/efeitos dos fármacos , Mercaptopurina/química , Mercaptopurina/farmacologia , Hidrogênio/química , Ligação de Hidrogênio/efeitos dos fármacos , Simulação de Dinâmica Molecular , Teoria Quântica
11.
Spectrochim Acta A Mol Biomol Spectrosc ; 188: 647-658, 2018 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-28793280

RESUMO

In the current study, the probability of complex formation between mercaptopurine drug with cucurbit[6]urils and cucurbit[7]urils has been investigated. The calculations for geometry optimization of complexes have been carried out by means of DFT (B3LYP), DFT-D (B3LYP-D) and M06-2X methods. The Atoms In Molecules (AIM), Natural Bond Orbital (NBO), NMR, the density of states (DOSs) and frontier molecular orbital (MO) analyses have been done on the inclusion complexes. In addition, the UV-Vis spectra of the first eight states have been obtained by CAM-B3LYP/TD-DFT calculation. The obtained results of the complexation process reveal that CB[7]-DRG complexes are more favorable than that of CB[6]-DRG interactions. Furthermore, our theoretical results show that configurations III and I are the most stable configurations related to the CB[6]/DRG and CB[7]/DRG interactions, respectively. The positive ∇2ρ(r) and HC values at the bond critical points indicate that exist the weak H-bonds between CB[6] and CB[7] with H atoms of the drug molecule. The obtained negative binding energy values of CB[7]-DRG interaction in solution phase show the stability of these complexes in the aqueous medium. Also, all of the observed parameters of molecular dynamics simulation such as the number of contacts, hydrogen bonding, center-of-mass distance and van der Waals energy values confirm the encapsulation of mercaptopurine molecule inside the cucurbit[7]urils cavity at about 3.2ns.


Assuntos
Elétrons , Compostos Macrocíclicos/química , Mercaptopurina/química , Simulação de Dinâmica Molecular , Teoria Quântica , Interações Hidrofóbicas e Hidrofílicas , Espectroscopia de Ressonância Magnética , Conformação Molecular , Solventes/química , Espectrofotometria Ultravioleta , Eletricidade Estática , Termodinâmica
12.
Clin Chem Lab Med ; 56(5): 803-809, 2018 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-29194039

RESUMO

BACKGROUND: Variation in metabolism, toxicity and therapeutic efficacy of thiopurine drugs is largely influenced by genetic polymorphisms in the thiopurine S-methyltransferase (TPMT) gene. Determination of TPMT activity is routinely performed in patients to adjust drug therapy. METHODS: We further optimized a previously established high-performance liquid chromatography (HPLC) method by measuring TPMT activity in whole blood instead of isolated erythrocytes, which is based on conversion of 6-mercaptopurine to 6-methylmercaptopurine using S-adenosyl-methionine as methyl donor. RESULTS: The simplified TPMT whole-blood method showed similar or better analytical and diagnostic performance compared with the former erythrocyte assay. The whole-blood method was linear for TPMT activities between 0 and 40 nmol/(mL·h) with a quantification limit of 0.1 nmol/(mL·h). Within-day imprecision and between-day imprecision were ≤5.1% and ≤8.5%, respectively. The optimized method determining TPMT activity in whole blood (y) showed agreement with the former method determining TPMT activity in erythrocytes (x) (n=45, y=1.218+0.882x; p>0.05). Phenotype-genotype concordance (n=300) of the whole-blood method was better when TPMT activity was expressed per volume of whole blood (specificity 92.2%), whereas correction for hematocrit resulted in lower genotype concordance (specificity 86.9%). A new cutoff for the whole-blood method to distinguish normal from reduced TPMT activity was determined at ≤6.7 nmol/(mL·h). CONCLUSIONS: This optimized TPMT phenotyping assay from whole blood using 6-MP as substrate is suitable for research and routine clinical analysis.


Assuntos
Mercaptopurina/análogos & derivados , Metiltransferases/sangue , Metiltransferases/metabolismo , Cromatografia Líquida de Alta Pressão , Genótipo , Voluntários Saudáveis , Humanos , Mercaptopurina/química , Mercaptopurina/metabolismo , Metiltransferases/genética , Fenótipo , Especificidade por Substrato
13.
Spectrochim Acta A Mol Biomol Spectrosc ; 192: 411-419, 2018 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-29197275

RESUMO

Presently, the combination of carbon quantum dots (CQDs) and metal oxide nanostructures in one frame are being considered for the sensing of purine compounds. In this work, a combined system of CQDs and MnO2 nanostructures was used for the detection of anticancer drugs, 6-Thioguanine (6-TG) and 6-Mercaptopurine (6-MP). The CQDs were synthesized through microwave synthesizer and the MnO2 nanostructures (nanoflowers and nanosheets) were synthesized using facile hydrothermal technique. The CQDs exhibited excellent fluorescence emission at 420nm when excited at 320nm wavelength. By combining CQDs and MnO2 nanostructures, quenching of fluorescence was observed which was attributed to fluorescence resonance energy transfer (FRET) mechanism, where CQDs act as electron donor and MnO2 act as acceptor. This fluorescence quenching behaviour disappeared on the addition of 6-TG and 6-MP due to the formation of Mn-S bond. The detection limit for 6-TG (0.015µM) and 6-MP (0.014µM) was achieved with the linear range of concentration (0-50µM) using both MnO2 nanoflowers and nanosheets. Moreover, the as-prepared fluorescence-sensing technique was successfully employed for the detection of bio-thiol group in enapril drug. Thus a facile, cost-effective and benign chemistry approach for biomolecule detection was designed.


Assuntos
Carbono/química , Corantes Fluorescentes/química , Compostos de Manganês/química , Nanocompostos/química , Óxidos/química , Pontos Quânticos/química , Compostos de Sulfidrila/análise , Difusão Dinâmica da Luz , Cinética , Mercaptopurina/química , Espectroscopia Fotoeletrônica , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Tioguanina/química
14.
Int J Mol Sci ; 19(1)2017 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-29283382

RESUMO

Drug repositioning is the application of the existing drugs to new uses and has the potential to reduce the time and cost required for the typical drug discovery process. In this study, we repositioned thiopurine drugs used for the treatment of acute leukaemia as new tyrosinase inhibitors. Tyrosinase catalyses two successive oxidations in melanin biosynthesis: the conversions of tyrosine to dihydroxyphenylalanine (DOPA) and DOPA to dopaquinone. Continuous efforts are underway to discover small molecule inhibitors of tyrosinase for therapeutic and cosmetic purposes. Structure-based virtual screening predicted inhibitor candidates from the US Food and Drug Administration (FDA)-approved drugs. Enzyme assays confirmed the thiopurine leukaemia drug, thioguanine, as a tyrosinase inhibitor with the inhibitory constant of 52 µM. Two other thiopurine drugs, mercaptopurine and azathioprine, were also evaluated for their tyrosinase inhibition; mercaptopurine caused stronger inhibition than thioguanine did, whereas azathioprine was a poor inhibitor. The inhibitory constant of mercaptopurine (16 µM) was comparable to that of the well-known inhibitor kojic acid (13 µM). The cell-based assay using B16F10 melanoma cells confirmed that the compounds inhibit mammalian tyrosinase. Particularly, 50 µM thioguanine reduced the melanin content by 57%, without apparent cytotoxicity. Cheminformatics showed that the thiopurine drugs shared little chemical similarity with the known tyrosinase inhibitors.


Assuntos
Azatioprina/farmacologia , Reposicionamento de Medicamentos , Inibidores Enzimáticos/farmacologia , Melaninas/antagonistas & inibidores , Mercaptopurina/farmacologia , Monofenol Mono-Oxigenase/antagonistas & inibidores , Doença Aguda , Antimetabólitos Antineoplásicos/química , Antimetabólitos Antineoplásicos/uso terapêutico , Azatioprina/química , Domínio Catalítico , Ensaios Enzimáticos , Inibidores Enzimáticos/química , Humanos , Leucemia/tratamento farmacológico , Leucemia/enzimologia , Leucemia/genética , Leucemia/patologia , Melaninas/biossíntese , Melaninas/genética , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/enzimologia , Melanoma Experimental/genética , Melanoma Experimental/patologia , Mercaptopurina/química , Simulação de Acoplamento Molecular , Monofenol Mono-Oxigenase/química , Monofenol Mono-Oxigenase/genética , Monofenol Mono-Oxigenase/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Relação Estrutura-Atividade , Tioguanina/química , Tioguanina/uso terapêutico , Células Tumorais Cultivadas
15.
Carbohydr Polym ; 177: 22-31, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28962762

RESUMO

As a novel strategy to overcome some of the therapeutic disadvantages of 6-thioguanine (TG) and 6-mercaptopurine (MP), we propose the inclusion of these drugs in ßcyclodextrin (ßCD) to form the complexes ßCD-TG and ßCD-MP, followed by subsequent interaction with gold nanoparticles (AuNPs), generating the ternary systems: ßCD-TG-AuNPs and ßCD-MP-AuNPs. This modification increased their solubility and improved their stability, betting by a site-specific transport due to their nanometric dimensions, among other advantages. The formation of the complexes was confirmed using powder X-ray diffraction, thermogravimetric analysis and one and two-dimensional NMR. A theoretical study using DFT and molecular modelling was conducted to obtain the more stable tautomeric species of TG and MP in solution and confirm the proposed inclusion geometries. The deposition of AuNPs onto ßCD-TG and ßCD-MP via sputtering was confirmed by UV-vis spectroscopy. Subsequently, the ternary systems were characterized by TEM, FE-SEM and EDX to directly observe the deposited AuNPs and evaluate their sizes, size dispersion, and composition. Finally, the in vitro permeability of the ternary systems was studied using parallel artificial membrane permeability assay (PAMPA).


Assuntos
Portadores de Fármacos/síntese química , Ouro/química , Mercaptopurina/química , Nanopartículas Metálicas/química , Tioguanina/química , beta-Ciclodextrinas/química , Solubilidade
16.
Biomacromolecules ; 18(10): 3207-3214, 2017 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-28835099

RESUMO

6-Mercaptopurine (6-MP) is an essential medicine used for treating leukemia in the clinics. 6-MP suffers, however, from poor water solubility, low bioavailability, and significant side effects. Here, we designed CD44-targeted glutathione-sensitive hyaluronic acid-mercaptopurine prodrug (HA-GS-MP) linked via carbonyl vinyl sulfide for safer and enhanced treatment of acute myeloid leukemia (AML). HA-GS-MP obtained with 50 kDa HA and 6-MP conjugation content of 6.9 wt % showed excellent water solubility with a hydrodynamic size of ca. 15 nm. Intriguingly, HA-GS-MP was extremely stable, without any drug leakage, under physiological environment while rapidly releasing 6-MP in response to 10 mM glutathione. HA-GS-MP exhibited obvious targetability and markedly enhanced antitumor effect to OCI/AML-2 human AML cells (IC50 = 16.9 µg 6-MP equiv./mL). The pharmacokinetic studies displayed that Cy5-labeled HA-GS-MP had a long circulation time in mice (elimination half-life = 4.37 h). The in vivo fluorescence images demonstrated strong and persistent accumulation of Cy5-labeled HA-GS-MP from 4 to 48 h post injection in the subcutaneous OCI/AML-2 tumor in nude mice. Notably, HA-GS-MP while causing little side effects induced significantly enhanced growth inhibition of OCI/AML-2 tumor and better survival rate of OCI/AML-2 tumor-bearing mice as compared to free 6-MP. Carbonyl vinyl sulfide-linked hyaluronic acid-mercaptopurine prodrug has appeared to be a simple and smart nanomedicine for targeted treatment of AML.


Assuntos
Antimetabólitos Antineoplásicos/química , Glutationa/química , Receptores de Hialuronatos/metabolismo , Leucemia Mieloide Aguda/tratamento farmacológico , Mercaptopurina/química , Nanopartículas/química , Pró-Fármacos/química , Animais , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Humanos , Ácido Hialurônico/química , Mercaptopurina/administração & dosagem , Mercaptopurina/farmacocinética , Camundongos , Pró-Fármacos/farmacocinética , Eliminação Renal , Distribuição Tecidual , Compostos de Vinila/química
17.
Int J Pharm ; 520(1-2): 126-138, 2017 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-28167261

RESUMO

Cancer is considered to be one of the leading causes of morbidity and mortality worldwide and nanotechnology was shown to have a unique potential to enhance the therapeutic performance of anti-cancer agents. A novel dual stimuli-responsive polyethylene glycol (PEG) block copolymer was synthesized for the decoration and stabilization of gold nanoparticles (NPs) to carry multiple anti-cancer drugs, doxorubicin (DOX), methotrexate (MTX) and 6-mercaptopurine (MP). DOX, MTX and MP were successfully loaded (the loading capacity of 37%, 12%, and 49%, respectively) into the NPs by ionic interaction (DOX and MTX) and disulphide-covalent bond formation (MP) in the polymeric shell of NPs. Furthermore, the triggered drugs release ability of NPs was shown through the comparison of simulated physiological and tumor tissue environments. The enhanced efficiency of the developed NPs and their targeted performance via MTX (target ligand of folate receptors) decoration were illustrated through the various cell cytotoxicity studies such as MTT assay, DAPI staining, and flow cytometry on various cancer cell lines with different levels of folate receptors. Our proposed idea in simultaneous delivery of three cytotoxic drugs with our newly designed PEGylated gold NPs may provide promising and novel prospect in cancer therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Portadores de Fármacos/química , Ouro/química , Nanopartículas Metálicas/química , Protocolos de Quimioterapia Combinada Antineoplásica/química , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Linhagem Celular Tumoral , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Concentração de Íons de Hidrogênio , Mercaptopurina/administração & dosagem , Mercaptopurina/química , Mercaptopurina/farmacocinética , Mercaptopurina/farmacologia , Metotrexato/administração & dosagem , Metotrexato/química , Metotrexato/farmacocinética , Metotrexato/farmacologia , Oxirredução , Polietilenoglicóis/química
18.
Biomed Chromatogr ; 31(9)2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28212467

RESUMO

Thiopurines (TPDs) are first-line drugs in treating neuromyelitis optica spectrum disorders (NMOSD). Evaluation of thiopurine S-methyltransferase activity (TPMT), a major determinant of TPD toxicity, before TPD treatment using 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG) as substrate was suggested. However, the equivalent of the two substrates in TPMT activity evaluation was unknown, and an alternative substrate was required in TPMT activity evaluation in patients who were already taking 6-MP or 6-TG. Before evaluating the agreement of 6-MP and 6-TG in TPMT activity measurement in patients with NMOSD, the affinity of the two substrates for the active center of TPMT should be established. A computer-based simulation indicated that 6-MP and 6-TG had similar affinities for the two active sites of TPMT. According to the guidelines, an LC-MS/MS method was developed and validated to evaluate the TPMT activity in human erythrocyte hemolysate using 6-MP or 6-TG as substrates via 1 h incubation at 37°C. The method was applied in 81 patients with NMOSD. Evaluated by Bland-Altman plot, 6-methylmercaptopurine and 6-methylthioguanine represented TPMT activities were in agreement with each other. Further studies are warranted to confirm the results.


Assuntos
Cromatografia Líquida/métodos , Eritrócitos/enzimologia , Mercaptopurina/metabolismo , Metiltransferases/sangue , Metiltransferases/metabolismo , Espectrometria de Massas em Tandem/métodos , Tioguanina/metabolismo , Adolescente , Adulto , Idoso , Estabilidade de Medicamentos , Feminino , Humanos , Modelos Lineares , Masculino , Mercaptopurina/química , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tioguanina/química , Adulto Jovem
19.
Luminescence ; 32(4): 502-508, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27594674

RESUMO

A highly sensitive method for the detection of 6-mercaptopurine (MP) by resonance Rayleigh light scattering (RLS) method was developed. Gold nanoparticles (AuNPs) were synthesized by a modified seed method and characterized using transmission electron microscopy (TEM). AuNPs were bound to MP via covalent bonding to form the MP-AuNPs complex, which increased the RLS intensity of MP at 347 nm (increased by 65.7%). Under optimum conditions, the magnitude of the enhanced RLS intensity for MP-AuNPs was proportional to MP concentration in the range 0.0681-1.702 µg mL-1 . The linear regression equation was represented as follows: ΔIRLS = 9.31 + 82.42c (r = 0.9948). The limit of detection (LOD, 3σ) was 3.32 ng mL-1 . The system was applied successfully to detect MP in pharmaceuticals. MP recoveries were 99.9-101.7% with a relative standard deviation (RSD) (n = 5) of 0.59-0.77% for three synthetic samples, and 97.5-110.0% with an RSD of 0.98-2.10% (n = 5) for tablet samples.


Assuntos
Difusão Dinâmica da Luz/métodos , Mercaptopurina/análise , Nanopartículas Metálicas/química , Calibragem , Difusão Dinâmica da Luz/normas , Ouro/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Modelos Lineares , Mercaptopurina/química , Mercaptopurina/metabolismo , Microscopia Eletrônica de Transmissão , Concentração Osmolar , Sensibilidade e Especificidade , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Comprimidos/análise
20.
Drug Des Devel Ther ; 10: 3933-3946, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27942204

RESUMO

In the treatment of cancer patients, cisplatin (CDDP) exhibits serious cardiac and renal toxicities, while classical combinations related to CDDP are unable to solve these problems and may result in worse prognosis. Alternately, this study covalently conjugated 6-mercaptopurine (6MP) onto the surface of mercapto-modified mesoporous silica nanoparticles (MSNS) to form MSNS-6MP and loaded CDDP into the holes on the surface of MSNS-6MP to form MSNS-6MP/CDDP, a tumor-targeting nano-releasing regime for CDDP and 6MP specifically. In the S180 mouse model, the anti-tumor activity and overall survival of MSNS-6MP/CDDP (50 mg·kg-1·day-1, corresponding to 1 mg·kg-1·day-1 of 6MP and 5 mg·kg-1·day-1 of CDDP) were significantly higher than those of CDDP alone (5 mg·kg-1·day-1) or CDDP (5 mg·kg-1·day-1) plus 6MP (1 mg·kg-1·day-1). The assays of serum alanine aminotransferase, aspartate aminotransferase and creatinine, as well as the images of myocardium and kidney histology, support that MSNS-6MP/CDDP is able to completely eliminate liver, kidney and heart toxicities induced by CDDP alone or CDDP plus 6MP.


Assuntos
Antineoplásicos/administração & dosagem , Cisplatino/administração & dosagem , Portadores de Fármacos , Mercaptopurina/administração & dosagem , Nanopartículas , Sarcoma 180/tratamento farmacológico , Dióxido de Silício/química , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/toxicidade , Cardiotoxicidade , Cisplatino/química , Cisplatino/metabolismo , Cisplatino/toxicidade , Composição de Medicamentos , Rim/efeitos dos fármacos , Rim/patologia , Cinética , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Mercaptopurina/química , Mercaptopurina/metabolismo , Mercaptopurina/toxicidade , Camundongos Endogâmicos ICR , Microscopia Eletrônica de Transmissão , Miocárdio/patologia , Nanotecnologia , Porosidade , Sarcoma 180/metabolismo , Sarcoma 180/patologia , Solubilidade , Tecnologia Farmacêutica/métodos , Distribuição Tecidual , Carga Tumoral/efeitos dos fármacos
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