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1.
PLoS One ; 19(8): e0306124, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39141629

RESUMO

Multidrug resistance (MDR) mechanisms in cancer cells are greatly influenced by glutathione transferase P1-1 (hGSTP1-1). The use of synthetic or natural compounds as hGSTP1-1 inhibitors is considered an effective approach to overcome MDR. Nine compounds consisting of coumarin-6-sulfonamide linked to chalcone derivatives were synthesized and evaluated for their ability to inhibit hGSTP1-1. Among the synthetic derivatives, compounds 5g, 5f, and 5a displayed the most potent inhibitory effect, with IC50 values of 12.2 ± 0.5 µΜ, 12.7 ± 0.7 and 16.3 ± 0.6, respectively. Kinetic inhibition analysis of the most potent molecule, 5g, showed that it behaves as a mixed-type inhibitor of the target enzyme. An in vitro cytotoxicity assessment of 5a, 5f, and 5g against the human prostate cancer cell lines DU-145 and PC3, as well as the breast cancer cell line MCF-7, demonstrated that compound 5g exhibited the most pronounced cytotoxic effect on all tested cell lines. Molecular docking studies were performed to predict the structural and molecular determinants of 5g, 5f, and 5a binding to hGSTP1-1. In agreement with the experimental data, the results revealed that 5g exhibited the lowest docking score among the three studied inhibitors as a consequence of shape complementarity, governed by van der Waals, hydrogen bonds and a π-π stacking interaction. These findings suggest that coumarin-chalcone hybrids offer new perspectives for the development of safe and efficient natural product-based sensitizers that can target hGSTP1-1 for anticancer purposes.


Assuntos
Cumarínicos , Glutationa S-Transferase pi , Simulação de Acoplamento Molecular , Sulfonamidas , Humanos , Cumarínicos/química , Cumarínicos/farmacologia , Glutationa S-Transferase pi/antagonistas & inibidores , Glutationa S-Transferase pi/metabolismo , Sulfonamidas/química , Sulfonamidas/farmacologia , Linhagem Celular Tumoral , Chalcona/química , Chalcona/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Chalconas/química , Chalconas/farmacologia , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Células MCF-7
2.
Nanotechnology ; 35(34)2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38788695

RESUMO

Although chlorambucil (CHL) is a long-established anticancer drug, the drug failure of CHL, mediated by the intracellular defense system consisting of glutathione (GSH) and GSH S-transferase pi (GST-pi), has significantly limited the application of CHL. To overcome this issue, we first designed a GSH-responsive small-molecule prodrug (EA-SS-CHL) by combining CHL and ethacrynic acid (EA). Subsequently, drug-loaded nanoparticles (ECPP) were formed by the self-assembly between EA-SS-CHL and amphiphilic PEG-PDLLA to improve the water solubility of the prodrug and its ability to target tumor sites. Upon exposure to high intracellular GSH concentration, EA-SS-CHL gradually degrades, leading to the release of EA and CHL. The presence of EA facilitates the depletion of GSH and inhibition of GST-pi, ultimately attenuating the detoxification of the intracellular defense system to CHL. Cytotoxicity studies and apoptosis assays demonstrate that ECPP exhibits higher therapeutic efficiency than CHL. Additionally,in vivotumor suppression effects and biocompatibility provide further evidence for the superiority of ECPP. This work presents a promising strategy to enhance the efficacy of CHL in cancer therapy.


Assuntos
Clorambucila , Ácido Etacrínico , Glutationa , Micelas , Pró-Fármacos , Clorambucila/farmacologia , Clorambucila/química , Pró-Fármacos/farmacologia , Pró-Fármacos/química , Glutationa/metabolismo , Humanos , Animais , Ácido Etacrínico/farmacologia , Ácido Etacrínico/química , Nanopartículas/química , Camundongos , Glutationa S-Transferase pi/metabolismo , Glutationa S-Transferase pi/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/química , Polietilenoglicóis/química , Glutationa Transferase/metabolismo , Portadores de Fármacos/química , Liberação Controlada de Fármacos
3.
Comput Biol Chem ; 108: 107981, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37976621

RESUMO

Chemoresistance, a significant challenge in cancer treatment, is often associated with the cellular glutathione-related detoxification system. The GSTP1 isoenzyme (glutathione S-transferases) plays a critical role in the cytoplasmic inactivation of anticancer drugs. This suggests the identification of GSTP1 inhibitors to combat chemoresistance. We screened Sophoretin (also called quercetin) derivatives for molecular properties, pharmacokinetics, and toxicity profiles. Following that, we conducted molecular docking and simulations between selected derivatives and GSTP1. The best-docked complex, GSTP1-quercetin 7-O-ß-D-glucoside, exhibited a binding affinity of -8.1 kcal/mol, with no predicted toxicity and good pharmacokinetic properties. Molecular dynamics simulations confirmed the stability of this complex. Quercetin 7-O-ß-D-glucoside shows promise as a lead candidate for addressing chemoresistance in cancer patients, although further experimental studies are needed to validate its efficacy and therapeutic potential.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Glutationa S-Transferase pi , Quercetina , Humanos , Glucosídeos , Glutationa , Glutationa S-Transferase pi/antagonistas & inibidores , Simulação de Acoplamento Molecular , Quercetina/química , Quercetina/farmacologia
4.
J Med Chem ; 64(21): 15582-15592, 2021 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-34623802

RESUMO

The "inverse drug discovery" strategy is a potent means of exploring the cellular targets of latent electrophiles not typically used in medicinal chemistry. Cyclopropenone, a powerful electrophile, is generally used in bio-orthogonal reactions mediated by triarylphosphine or in photo-triggered cycloaddition reactions. Here, we have studied, for the first time, the proteome reactivity of cyclopropenones in live cells and discovered that the cyclopropenone warhead can specifically and efficiently modify a triple-negative breast cancer driver, glutathione S-transferase pi-1 (GSTP1), by covalently binding at the catalytic active site. Further structure optimization and signaling pathway validation have led to the discovery of potent inhibitors of GSTP1.


Assuntos
Antineoplásicos/farmacologia , Ciclopropanos/farmacologia , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Glutationa S-Transferase pi/antagonistas & inibidores , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ciclopropanos/síntese química , Ciclopropanos/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Glutationa S-Transferase pi/metabolismo , Humanos , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia
5.
Int J Mol Sci ; 22(8)2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33920860

RESUMO

Glutathione transferases (GSTs) form a family of detoxication enzymes instrumental in the inactivation and elimination of electrophilic mutagenic and carcinogenic compounds. The Pi class GST P1-1 is present in most tissues and is commonly overexpressed in neoplastic cells. GST P1-1 in the dog, Canis lupus familiaris, has merits as a marker for tumors and as a target for enzyme-activated prodrugs. We produced the canine enzyme CluGST P1-1 by heterologous bacterial expression and verified its cross-reactivity with antihuman-GST P1-1 antibodies. The catalytic activity with alternative substrates of biological significance was determined, and the most active substrate found was benzyl isothiocyanate. Among established GST inhibitors, Cibacron Blue showed positive cooperativity with an IC50 value of 43 nM. Dog GST P1-1 catalyzes activation of the prodrug Telcyta, but the activity is significantly lower than that of the human homolog.


Assuntos
Glutationa S-Transferase pi/metabolismo , Medicina Veterinária , Sequência de Aminoácidos , Animais , Biocatálise , Cães , Glutationa S-Transferase pi/antagonistas & inibidores , Glutationa S-Transferase pi/química , Glutationa S-Transferase pi/isolamento & purificação , Humanos , Modelos Moleculares , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Estrutura Terciária de Proteína , Especificidade por Substrato
6.
Angew Chem Int Ed Engl ; 60(6): 3196-3204, 2021 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-33155344

RESUMO

Despite being a clinically approved intervention for cancer, photodynamic therapy (PDT) still suffers from limitations. Prime among these is a therapeutic response that is mostly oxygen dependent. This limits the utility of PDT in treating hypoxic tumors since lower levels of cytotoxic reactive oxygen species (ROS) are generated in regions of low oxygen tension. Glutathione-pi (GST-pi) is a key enzyme that militates against ROS-mediated apoptosis. We report herein a new construct, EA-BPS, that contains both a brominated BODIPY photosensitizer (BPS) and an ethacrynic acid (EA) GST-pi inhibitor. Photoirradiation of EA-BPS induces a synergistic antitumor effect that results from the combination of ROS production and GST-pi inhibition. Relative to BPS alone, an enhanced cell-killing effect is seen under hypoxic conditions both in vitro and in vivo. We conclude that by making better use of the available oxygen in tumor environments, improved therapeutic PDT outcomes should be achievable even under hypoxic conditions.


Assuntos
Compostos de Boro/química , Ácido Etacrínico/química , Fármacos Fotossensibilizantes/química , Espécies Reativas de Oxigênio/metabolismo , Animais , Apoptose/efeitos dos fármacos , Hipóxia Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Glutationa S-Transferase pi/antagonistas & inibidores , Glutationa S-Transferase pi/metabolismo , Halogenação , Humanos , Luz , Camundongos , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Transplante Heterólogo
7.
J Hematol Oncol ; 13(1): 141, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-33087132

RESUMO

BACKGROUND: Glioblastoma (GBM) is a universally lethal tumor with frequently overexpressed or mutated epidermal growth factor receptor (EGFR). NADPH quinone oxidoreductase 1 (NQO1) and glutathione-S-transferase Pi 1 (GSTP1) are commonly upregulated in GBM. NQO1 and GSTP1 decrease the formation of reactive oxygen species (ROS), which mediates the oxidative stress and promotes GBM cell proliferation. METHODS: High-throughput screen was used for agents selectively active against GBM cells with EGFRvIII mutations. Co-crystal structures were revealed molecular details of target recognition. Pharmacological and gene knockdown/overexpression approaches were used to investigate the oxidative stress in vitro and in vivo. RESULTS: We identified a small molecular inhibitor, "MNPC," that binds to both NQO1 and GSTP1 with high affinity and selectivity. MNPC inhibits NQO1 and GSTP1 enzymes and induces apoptosis in GBM, specifically inhibiting the growth of cell lines and primary GBM bearing the EGFRvIII mutation. Co-crystal structures between MNPC and NQO1, and molecular docking of MNPC with GSTP1 reveal that it binds the active sites and acts as a potent dual inhibitor. Inactivation of both NQO1 and GSTP1 with siRNA or MNPC results in imbalanced redox homeostasis, leading to apoptosis and mitigated cancer proliferation in vitro and in vivo. CONCLUSIONS: Thus, MNPC, a dual inhibitor for both NQO1 and GSTP1, provides a novel lead compound for treating GBM via the exploitation of specific vulnerabilities created by mutant EGFR.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Glutationa S-Transferase pi/antagonistas & inibidores , NAD(P)H Desidrogenase (Quinona)/antagonistas & inibidores , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Descoberta de Drogas , Glioblastoma/metabolismo , Glutationa S-Transferase pi/metabolismo , Humanos , Simulação de Acoplamento Molecular , NAD(P)H Desidrogenase (Quinona)/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia
8.
Proc Natl Acad Sci U S A ; 117(32): 19435-19445, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32719131

RESUMO

The Ras/RAF/MEK/ERK pathway is an essential signaling cascade for various refractory cancers, such as those with mutant KRAS (mKRAS) and BRAF (mBRAF). However, there are unsolved ambiguities underlying mechanisms for this growth signaling thereby creating therapeutic complications. This study shows that a vital component of the pathway CRAF is directly impacted by an end product of the cascade, glutathione transferases (GST) P1 (GSTP1), driving a previously unrecognized autocrine cycle that sustains proliferation of mKRAS and mBRAF cancer cells, independent of oncogenic stimuli. The CRAF interaction with GSTP1 occurs at its N-terminal regulatory domain, CR1 motif, resulting in its stabilization, enhanced dimerization, and augmented catalytic activity. Consistent with the autocrine cycle scheme, silencing GSTP1 brought about significant suppression of proliferation of mKRAS and mBRAF cells in vitro and suppressed tumorigenesis of the xenografted mKRAS tumor in vivo. GSTP1 knockout mice showed significantly impaired carcinogenesis of mKRAS colon cancer. Consequently, hindering the autocrine loop by targeting CRAF/GSTP1 interactions should provide innovative therapeutic modalities for these cancers.


Assuntos
Glutationa S-Transferase pi/metabolismo , Neoplasias/patologia , Proteínas Proto-Oncogênicas c-raf/metabolismo , Animais , Carcinogênese , Linhagem Celular Tumoral , Proliferação de Células , Glutationa S-Transferase pi/antagonistas & inibidores , Glutationa S-Transferase pi/deficiência , Glutationa S-Transferase pi/genética , Humanos , Camundongos , Camundongos Knockout , Mutação , Neoplasias/genética , Neoplasias/metabolismo , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas/genética , Multimerização Proteica , Estabilidade Proteica , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas c-raf/química , Proteínas Proto-Oncogênicas c-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/genética , Transdução de Sinais
9.
Biochem Pharmacol ; 178: 114092, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32535103

RESUMO

Ovarian cancer is one of the leading causes of mortality in women worldwide. Currently, paclitaxel is one of the most effective chemotherapies. However, resistance to paclitaxel is a major cause of therapy failure and the precise mechanism of paclitaxel resistance remains unclear. In this study, we demonstrated that the oxidative pentose phosphate pathway (PPP) enzyme glucose-6-phosphate dehydrogenase (G6PD) promotes paclitaxel resistance. We showed that G6PD expression was higher in paclitaxel-resistant cancer cells than in their paclitaxel-sensitive counterparts. Furthermore, we demonstrated that suppressing G6PD using shRNA, or an inhibitor, either as single agents or in combination, sensitized paclitaxel-resistant cancer cells to paclitaxel treatment and thereby improving the therapeutic efficacy of paclitaxel. Interestingly, we found that the upregulation of G6PD in paclitaxel-resistant cells was due to the decreased expression of protein arginine methyltransferase 6 (PRMT6), which targets the promoter of G6PD. We further identified that G6PD promotes paclitaxel resistance by regulating the expression of glutathione S-transferase P1 (GSTP1), which confers resistance to chemotherapy by detoxifying several anticancer drugs. Taken together, our results suggest that G6PD is a novel potential target to overcome paclitaxel resistance.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Glucosefosfato Desidrogenase/metabolismo , Glutationa S-Transferase pi/biossíntese , Neoplasias Ovarianas/metabolismo , Paclitaxel/metabolismo , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos/fisiologia , Feminino , Glucosefosfato Desidrogenase/antagonistas & inibidores , Glutationa S-Transferase pi/antagonistas & inibidores , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Paclitaxel/administração & dosagem
10.
Biochem Pharmacol ; 178: 114060, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32473836

RESUMO

The 7-nitrobenzo[c][1,2,5]oxadiazole (NBD) derivative NBDHEX (compound 1) and its analogue MC3181 (compound 2) have been found to be potent inhibitors of tumor cell growth in vitro and therapeutically active and safe in mice bearing human melanoma xenografts. To enhance the aqueous solubility of these compounds, we synthesized the hemisuccinate of 1 (compound 3) and the phosphate monoesters of 1 and 2 (compound 4 and 5, respectively). These novel NBD derivatives displayed a solubility in the conventional phosphate-buffered saline up to 150-fold higher than that of 1, and up to 4-fold higher than that of 2. Notably, solubility of phosphates 4 and 5 in a potassium phosphate buffer at pH 7.4, was up to 500-fold higher than that of 1, and ~10-fold higher than that of 2. Compounds 3-5 retained high cytotoxicity towards cultured human melanoma and osteosarcoma cells and were cleaved in vitro by both human and murine hydrolases, thus releasing the corresponding parent compound (i.e., 1 or 2). Interestingly, esters 3-5 displayed high inhibitory activity towards the glutathione transferase (GST) isoform GSTP1-1 and showed a reactivity towards reduced glutathione comparable to that of the respective parent compound. Finally, both 4 and 5 were safe and effective when administered intravenously or orally as an aqueous solution to mice xenografted with A375 human melanoma tumors. Collectively, these results and the previously observed synergistic interaction between 1 and 2 and various approved anticancer drugs, suggest the possible utility of phosphates 4 and 5 as single agents and in combination regimens in cancers with unmet medical need, including melanoma.


Assuntos
4-Cloro-7-nitrobenzofurazano/metabolismo , Antineoplásicos/metabolismo , Glutationa S-Transferase pi/antagonistas & inibidores , Glutationa S-Transferase pi/metabolismo , Neoplasias/metabolismo , Água/metabolismo , 4-Cloro-7-nitrobenzofurazano/química , 4-Cloro-7-nitrobenzofurazano/uso terapêutico , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Ésteres/química , Ésteres/metabolismo , Feminino , Glutationa Transferase/antagonistas & inibidores , Glutationa Transferase/metabolismo , Humanos , Masculino , Camundongos , Camundongos Nus , Neoplasias/tratamento farmacológico , Solubilidade , Água/química , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
11.
Sci Rep ; 9(1): 14867, 2019 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619723

RESUMO

We previously showed that curcumin, a phytopolyphenol found in turmeric (Curcuma longa), targets a series of enzymes in the ROS metabolic pathway, induces irreversible growth arrest, and causes apoptosis. In this study, we tested Pentagamavunon-1 (PGV-1), a molecule related to curcumin, for its inhibitory activity on tumor cells in vitro and in vivo. PGV-1 exhibited 60 times lower GI50 compared to that of curcumin in K562 cells, and inhibited the proliferation of cell lines derived from leukemia, breast adenocarcinoma, cervical cancer, uterine cancer, and pancreatic cancer. The inhibition of growth by PGV-1 remained after its removal from the medium, which suggests that PGV-1 irreversibly prevents proliferation. PGV-1 specifically induced prometaphase arrest in the M phase of the cell cycle, and efficiently induced cell senescence and cell death by increasing intracellular ROS levels through inhibition of ROS-metabolic enzymes. In a xenograft mouse model, PGV-1 had marked anti-tumor activity with little side effects by oral administration, whereas curcumin rarely inhibited tumor formation by this administration. Therefore, PGV-1 is a potential therapeutic to induce tumor cell apoptosis with few side effects and low risk of relapse.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Curcumina/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Prometáfase/efeitos dos fármacos , Administração Oral , Oxirredutases do Álcool/antagonistas & inibidores , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/metabolismo , Animais , Antineoplásicos Fitogênicos/química , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Morte Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Divisão Celular/genética , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Curcumina/análogos & derivados , Glutationa S-Transferase pi/antagonistas & inibidores , Glutationa S-Transferase pi/genética , Glutationa S-Transferase pi/metabolismo , Glutationa Transferase/antagonistas & inibidores , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Células HEK293 , Células HeLa , Humanos , Células K562 , Lactoilglutationa Liase/antagonistas & inibidores , Lactoilglutationa Liase/genética , Lactoilglutationa Liase/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Células MCF-7 , Camundongos Nus , NAD(P)H Desidrogenase (Quinona)/antagonistas & inibidores , NAD(P)H Desidrogenase (Quinona)/genética , NAD(P)H Desidrogenase (Quinona)/metabolismo , Peroxirredoxinas/antagonistas & inibidores , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo , Prometáfase/genética , Espécies Reativas de Oxigênio/metabolismo , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
12.
J Enzyme Inhib Med Chem ; 34(1): 1131-1139, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31169043

RESUMO

The antitumor agent 6-((7-nitrobenzo[c][1,2,5]oxadiazol-4-yl)thio)hexan-1-ol (1) is a potent inhibitor of GSTP1-1, a glutathione S-transferase capable of inhibiting apoptosis by binding to JNK1 and TRAF2. We recently demonstrated that, unlike its parent compound, the benzoyl ester of 1 (compound 3) exhibits negligible reactivity towards GSH, and has a different mode of interaction with GSTP1-1. Unfortunately, 3 is susceptible to rapid metabolic hydrolysis. In an effort to improve the metabolic stability of 3, its ester group has been replaced by an amide, leading to N-(6-((7-nitrobenzo[c][1,2,5]oxadiazol-4-yl)thio)hexyl)benzamide (4). Unlike 3, compound 4 was stable to human liver microsomal carboxylesterases, but retained the ability to disrupt the interaction between GSTP1-1 and TRAF2 regardless of GSH levels. Moreover, 4 exhibited both a higher stability in the presence of GSH and a greater cytotoxicity towards cultured A375 melanoma cells, in comparison with 1 and its analog 2. These findings suggest that 4 deserves further preclinical testing.


Assuntos
4-Cloro-7-nitrobenzofurazano/farmacologia , Antineoplásicos/farmacologia , Benzamidas/farmacologia , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Glutationa S-Transferase pi/antagonistas & inibidores , 4-Cloro-7-nitrobenzofurazano/síntese química , 4-Cloro-7-nitrobenzofurazano/química , Antineoplásicos/síntese química , Antineoplásicos/química , Benzamidas/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/química , Glutationa S-Transferase pi/metabolismo , Humanos , Hidrólise , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade
13.
Cell Death Dis ; 10(5): 351, 2019 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-31024008

RESUMO

F-box only protein 8 (FBX8), as a critical component of the SKP1-CUL1-F-box (SCF) E3 ubiquitin ligases, has been associated with several malignancies through interacting with a member of proteins. However, the substrates of FBX8 for destruction in the progression of colorectal carcinoma (CRC) need to be explored. Here, we show that loss of FBX8 accelerates chemical-induced colon tumorigenesis. FBX8 directly targets GSTP1 for ubiquitin-mediated proteasome degradation in CRC. GSTP1 promotes the proliferation, invasion, and metastasis of CRC cells. Furthermore, GSTP1 is upregulated in CRC tissue samples and predicts poor prognosis of CRC patients. The inactivation of FBX8 negatively correlated with increased levels and stability of GSTP1 in clinical CRC tissues and FBX8 knockout transgenic mice. These findings identify a novel ubiquitination pathway as FBX8-GSTP1 axis that regulates the progression of CRC, which might be a potential prognostic biomarker for CRC patients.


Assuntos
Neoplasias Colorretais/patologia , Proteínas F-Box/metabolismo , Glutationa S-Transferase pi/metabolismo , Animais , Biomarcadores/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Neoplasias Colorretais/induzido quimicamente , Neoplasias Colorretais/mortalidade , Regulação para Baixo , Proteínas F-Box/antagonistas & inibidores , Proteínas F-Box/genética , Glutationa S-Transferase pi/antagonistas & inibidores , Glutationa S-Transferase pi/genética , Humanos , Estimativa de Kaplan-Meier , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Camundongos Transgênicos , Prognóstico , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Ubiquitinação
14.
Mol Cell Biochem ; 452(1-2): 95-104, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30076580

RESUMO

Oxidative stress is recognized as one of the major wrongdoers in Parkinson's disease (PD) while glutathione S-transferase (GST), an endogenous antioxidant, protects from oxidative stress-induced neurodegeneration. Despite GST-pi (GST-π) encounters the toxic manifestations in PD, its role in zinc (Zn)-induced nigrostriatal dopaminergic neurodegeneration remains elusive. The study aimed to explore the role of GST-π in Zn-induced Parkinsonism and its underlying molecular mechanism. Male Wistar rats were treated intraperitoneally with zinc (zinc sulfate), twice a week, for 2-12 weeks. GST-π inducer, benzyl isothiocyanate (BITC) was also administered in a few sets of experiments along with respective vehicle. Catalytic activity and expression of GST-π protein, total GST activity, neurobehavioral indexes, striatal dopamine and its metabolites, nigral tyrosine hydroxylase (TH)-positive neurons and expression of TH and B-cell lymphoma-2 (Bcl-2) proteins were reduced in Zn-treated rats. Conversely, oxidative stress indicators, c-jun N-terminal kinase (JNK) activation, c-jun phosphorylation, cytochrome c release, Bcl-2-associated X protein (Bax) translocation, and procaspase 3/9 to caspase 3/9 conversion were significantly increased in Zn-exposed rats. BITC ameliorated GST-π activity/expression and normalized Zn-induced changes in neurodegenerative indicators, oxidative stress, JNK activation, c-jun phosphorylation and apoptotic indexes. The results demonstrate that Zn inhibits GST-π expression leading to increased oxidative stress and JNK activation, which induce apoptosis thereby degeneration of the nigrostriatal dopaminergic neurons.


Assuntos
Apoptose , Neurônios Dopaminérgicos/patologia , Glutationa S-Transferase pi/antagonistas & inibidores , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Transtornos Parkinsonianos/patologia , Zinco/toxicidade , Animais , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Glutationa S-Transferase pi/genética , Glutationa S-Transferase pi/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Estresse Oxidativo , Transtornos Parkinsonianos/induzido quimicamente , Transtornos Parkinsonianos/metabolismo , Fosforilação , Ratos , Ratos Wistar , Oligoelementos/toxicidade
15.
Chembiochem ; 20(7): 900-905, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30548113

RESUMO

Glutathione S-transferase π (GSTP1-1 ) is overexpressed in many types of cancer and is involved in drug resistance. Therefore, GSTP1-1 is an important target in cancer therapy, and many GST inhibitors have been reported. We had previously developed an irreversible inhibitor, GS-ESF, as an effective GST inhibitor; however, its cellular permeability was too low for it to be used in inhibiting intracellular GST. We have now developed new irreversible inhibitors by introducing sulfonyl fluoride (SF) into chloronitrobenzene (CNB). The mechanism of action was revealed to be that CNBSF first reacts with glutathione (GSH) through an aromatic substitution in the cell, then the sulfonyl group on the GSH conjugate with CNBSF reacts with Tyr108 of GST to form a sulfonyl ester bond. Our new inhibitor irreversible inhibited GSTP1-1 both in vitro and in cellulo with a long duration of action.


Assuntos
Inibidores Enzimáticos/farmacologia , Glutationa S-Transferase pi/antagonistas & inibidores , Glutationa/análogos & derivados , Glutationa/farmacologia , Sulfonas/farmacologia , Sequência de Aminoácidos , Sítios de Ligação/efeitos dos fármacos , Linhagem Celular Tumoral , Inibidores Enzimáticos/síntese química , Glutationa/síntese química , Glutationa S-Transferase pi/química , Humanos , Simulação de Acoplamento Molecular , Sulfonas/síntese química , Tirosina/química
16.
Drug Des Devel Ther ; 12: 3535-3547, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30425455

RESUMO

Glutathione S-transferase π (GSTπ) is a Phase II metabolic enzyme that is an important facilitator of cellular detoxification. Traditional dogma asserts that GSTπ functions to catalyze glutathione (GSH)-substrate conjunction to preserve the macromolecule upon exposure to oxidative stress, thus defending cells against various toxic compounds. Over the past 20 years, abnormal GSTπ expression has been linked to the occurrence of tumor resistance to chemotherapy drugs, demonstrating that this enzyme possesses functions beyond metabolism. This revelation reveals exciting possibilities in the realm of drug discovery, as GSTπ inhibitors and its prodrugs offer a feasible strategy in designing anticancer drugs with the primary purpose of reversing tumor resistance. In connection with the authors' current research, we provide a review on the biological function of GSTπ and current developments in GSTπ-targeting drugs, as well as the prospects of future strategies.


Assuntos
Antineoplásicos/farmacologia , Glutationa S-Transferase pi/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Glutationa/antagonistas & inibidores , Glutationa/metabolismo , Glutationa S-Transferase pi/metabolismo , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Estresse Oxidativo/efeitos dos fármacos
17.
Environ Toxicol Pharmacol ; 61: 18-23, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29807309

RESUMO

Deltamethrin (DEL), which is a synthetic pyrethroid insecticide, has been used successfully all over the world to treat mosquito nets for the control of malaria. Glutathione S-transferases (GSTs; EC 2.5.1.18) catalyze the conjugation of reduced glutathione (GSH) to a variety of xenobiotics and are normally recognized as detoxification enzymes. Here, we used a colorimetric assay based on the human placental GSTP1-1 (hpGSTP1-1)-catalyzed reaction between GSH and the model substrate 1-chloro-2,4-dinitrobenzene (CDNB) as well as molecular docking to investigate the mechanistic and structural aspects of hpGSTP1-1 inhibition by DEL. We show that DEL is a potent, noncompetitive inhibitor of hpGSTP1-1 with an IC50 value of 6.1 µM and Ki values of 5.61 ±â€¯0.32 µM and 7.96 ±â€¯0.97 µM at fixed [CDNB]-varied [GSH] and fixed [GSH]-varied [CDNB], respectively. DEL appears to be accommodated well in an eccentric cavity located at the interface of the hpGSTP1-1 homodimer, presumably causing conformational changes to the enzyme's substrate-binding sites such that the enzyme is no longer able to transform GSH and CDNB effectively. Correspondingly, considerable maternal exposure to and subsequent accumulation of DEL may interfere with the proper development of the vulnerable fetus, possibly increasing the risk of developing congenital defects.


Assuntos
Glutationa S-Transferase pi/antagonistas & inibidores , Glutationa S-Transferase pi/metabolismo , Glutationa/metabolismo , Inseticidas/metabolismo , Nitrilas/metabolismo , Piretrinas/metabolismo , Dinitroclorobenzeno/metabolismo , Feminino , Humanos , Simulação de Acoplamento Molecular , Placenta/enzimologia , Gravidez
18.
Cell Physiol Biochem ; 45(1): 406-418, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29402793

RESUMO

BACKGROUND/AIMS: Inflammation-induced injury of the endothelial barrier occurs in several pathological conditions, including atherosclerosis, ischemia, and sepsis. Endothelial cytoskeleton rearrangement is an important pathological mechanism by which inflammatory stimulation triggers an increase of vascular endothelial permeability. However, the mechanism maintaining endothelial cell barrier function against inflammatory stress is not fully understood. Glutathione S-transferase pi (GSTpi) exists in various types of cells and protects them against different stresses. In our previous study, GSTpi was found to act as a negative regulator of inflammatory responses. METHODS: We used a Transwell permeability assay to test the influence of GSTpi and its transferase activity on the increase of endothelial permeability induced by tumor necrosis factor alpha (TNF-α). TNF-α-induced actin remodeling and the influence of GSTpi were observed by using laser confocal microscopy. Western blotting was used to test the influence of GSTpi on TNF-α-activated p38 mitogen-activated protein kinase (MAPK)/MK2/heat shock protein 27 (HSP27). RESULTS: GSTpi reduced TNF-α-induced stress fiber formation and endothelial permeability increase by restraining actin cytoskeleton rearrangement, and this reduction was unrelated to its transferase activity. We found that GSTpi inhibited p38MAPK phosphorylation by directly binding p38 and influenced downstream substrate HSP27-induced actin remodeling. CONCLUSION: GSTpi inhibited TNF-α-induced actin remodeling, stress fiber formation and endothelial permeability increase by inhibiting the p38MAPK/HSP27 signaling pathway.


Assuntos
Actinas/metabolismo , Glutationa S-Transferase pi/metabolismo , Células Cultivadas , Glutationa S-Transferase pi/antagonistas & inibidores , Glutationa S-Transferase pi/genética , Proteínas de Choque Térmico HSP27/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Imunoprecipitação , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Microscopia de Fluorescência , Permeabilidade/efeitos dos fármacos , Polimerização , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
19.
Talanta ; 179: 845-852, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29310316

RESUMO

Pi class glutathione S-transferase (GSTP1) is highly expressed in various cancerous cells and pre-neoplastic legions, where it is involved in apoptotic resistance or metabolism of several anti-tumour chemotherapeutics. Therefore, GSTP1 is a marker of malignant and pre-malignant cells and is a promising target for visualization and drug development. Here we demonstrate that fluorescein diacetate (FDA), a fluorescent probe used for vital staining, is a fluorescently activated by esterolytic activity of human GSTP1 (hGSTP1) selectively among various cytosolic GSTs. Fluorescence activation of FDA susceptible to GST inhibitors was observed in MCF7 cells exogenously overexpressing hGSTP1, but not in cells overexpressing hGSTA1 or hGSTM1. Inhibitor-sensitive fluorescence activation was also observed in several cancer cell lines endogenously expressing GSTP1, suggesting that GSTP1 is involved in FDA esterolysis in these cells. Among the FDA derivatives examined, FOMe-Ac, the acetyl ester of fluorescein O-methyl ether, was found to be a potential reporter for GSH-dependent GSTP1 activity as well as for carboxylesterase activity. Since GSTP1 is highly expressed in various types of cancer cells compared to their normal counterparts, improving the fluorogenic substrates to be more selective to the esterolysis activity of GSTP1 rather than carboxylesterases should lead to development of tools for detecting GSTP1-overexpressing cancer cells and investigating the biological functions of GSTP1.


Assuntos
Biomarcadores Tumorais/química , Fluoresceínas/química , Corantes Fluorescentes/química , Glutationa S-Transferase pi/química , Biomarcadores Tumorais/antagonistas & inibidores , Glutationa/química , Glutationa S-Transferase pi/antagonistas & inibidores , Glutationa Transferase/química , Células HeLa , Humanos , Células MCF-7 , Oxidiazóis/química , Espectrometria de Fluorescência , Especificidade por Substrato
20.
Biosci Rep ; 38(1)2018 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-29358310

RESUMO

The 7-nitro-2,1,3-nitrobenzoxadiazole (NBD) derivatives are a series of compounds containing the NBD scaffold that are not glutathione (GSH) peptidomimetics, and result in a strong inhibition of glutathione S-transferases (GSTs). Growing evidences highlight their pivotal roles and outstanding anticancer activity in different tumor models. In particular, 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio) hexanol (NBDHEX) is extensively studied, which is a very efficient inhibitor of GSTP1-1. It triggers apoptosis in several tumor cell lines and this cytotoxic activity is observed at micro and submicromolar concentrations. Importantly, studies have shown that NBDHEX acts as an anticancer drug by inhibiting GSTs catalytic activity, avoiding inconvenience of the inhibitor extrusion from the cell by specific pumps and disrupting the interaction between the GSTP1-1 and key signaling effectors. Additionally, some researchers also have discovered that NBDHEX can act as late-phase autophagy inhibitor, which opens new opportunities to fully exploit its therapeutic potential. In this review, we summarize the advantages, anticancer mechanisms, and analogs of this compound, which will establish the basis on the usage of NBDHEX in clinical applications in future.


Assuntos
Antineoplásicos/química , Glutationa S-Transferase pi/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Oxidiazóis/química , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Azóis/química , Azóis/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Glutationa S-Transferase pi/química , Hexanóis/química , Hexanóis/uso terapêutico , Humanos , Neoplasias/patologia , Nitrobenzenos/química , Nitrobenzenos/uso terapêutico , Oxidiazóis/uso terapêutico
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