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1.
J Med Chem ; 67(11): 9745-9758, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38819023

RESUMO

Herein, we describe the general design, synthesis, characterization, and biological activity of new multitargeting Pt(IV) prodrugs that combine antitumor cisplatin and dasatinib, a potent inhibitor of Src kinase. These prodrugs exhibit impressive antiproliferative and anti-invasive activities in tumor cell lines in both two-dimensional (2D) monolayers of cell cultures and three-dimensional (3D) spheroids. We show that the cisplatin moiety and dasatinib in the investigated Pt(IV) complexes are both involved in the mechanism of action in MCF7 breast cancer cells and act synergistically. Thus, combining dasatinib and cisplatin into one molecule, compared to using individual components in a mix, may bring several advantages, such as significantly higher activity in cancer cell lines and higher selectivity for tumor cells. Most importantly, Pt(IV)-dasatinib complexes hold significant promise for potential anticancer therapies by targeting epithelial-mesenchymal transition, thus preventing the spread and metastasis of tumors, a value unachievable by a simple combination of both individual components.


Assuntos
Antineoplásicos , Cisplatino , Dasatinibe , Sinergismo Farmacológico , Pró-Fármacos , Dasatinibe/farmacologia , Dasatinibe/química , Dasatinibe/síntese química , Humanos , Pró-Fármacos/farmacologia , Pró-Fármacos/química , Pró-Fármacos/síntese química , Cisplatino/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Proliferação de Células/efeitos dos fármacos , Linhagem Celular Tumoral , Células MCF-7 , Ensaios de Seleção de Medicamentos Antitumorais , Compostos Organoplatínicos/farmacologia , Compostos Organoplatínicos/química , Compostos Organoplatínicos/síntese química
2.
Adv Healthc Mater ; : e2400203, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38774999

RESUMO

The limited recapitulation of critical cancer features in 2D cultures causes poor translatability of preclinical results from in vitro assays to in vivo tumor models. This contributes to slow drug development with a low success rate. 3D cultures better recapitulate the tumor microenvironment, enabling more accurate predictions when screening drug candidates and improving the development of chemotherapeutics. Platinum (Pt) (IV) compounds are promising prodrugs designed to reduce the severe systemic toxicity of widely used Food and Drug Administration (FDA)-approved Pt(II) drugs such as cisplatin. Here, this work presents spatiotemporal evaluations in 3D colorectal cancer (CRC) spheroids of mitochondria-targeting Pt(IV) complexes. CRC spheroids provide a greater pathophysiological recapitulation of in vivo tumors than 2D cultures by a marked upregulation of the ABCG2 chemoresistance marker expression. Furthermore, new 3D-staining protocols are introduced to evaluate the real-time decrease in mitochondria membrane potential (ΔΨ) in CRC spheroids, and a Pt-sensing dye to quantify the Pt mitochondrial accumulation. Finally, this work demonstrates a correlation between in vitro results and the efficacy of the compounds in vivo. Overall, the CRC spheroids represent a fast and cost-effective model to assess the behavior of Pt compounds in vitro and predict their translational potential in CRC treatment.

3.
Inorg Chem Front ; 11(2): 534-548, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38235273

RESUMO

While platinum-based chemotherapeutic agents have established themselves as indispensable components of anticancer therapy, they are accompanied by a variety of side effects and the rapid occurrence of drug resistance. A promising strategy to address these challenges is the use of platinum(iv) prodrugs, which remain inert until they reach the tumor tissue, thereby mitigating detrimental effects on healthy cells. Typically, platinum drugs are part of combination therapy settings. Consequently, a very elegant strategy is the development of platinum(iv) prodrugs bearing a second, clinically relevant therapeutic in axial position. In the present study, we focused on gemcitabine as an approved antimetabolite, which is highly synergistic with platinum drugs. In addition, to increase plasma half-life and facilitate tumor-specific accumulation, an albumin-binding maleimide moiety was attached. Our investigations revealed that maleimide-cisplatin(iv)-gemcitabine complexes cannot carry sufficient amounts of gemcitabine to induce a significant effect in vivo. Consequently, we designed a carboplatin(iv) analog, that can be applied at much higher doses. Remarkably, this novel analog demonstrated impressive in vivo results, characterized by significant improvements in overall survival. Notably, these encouraging results could also be transferred to an in vivo xenograft model with acquired gemcitabine resistance, indicating the high potential of this approach.

4.
Angew Chem Int Ed Engl ; 62(42): e202310774, 2023 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-37646232

RESUMO

A multitargeting prodrug (2) that releases gemcitabine, oxaliplatin, and doxorubicin in their active form in cancer cells is a potent cytotoxic agent with nM IC50s ; it is highly selective to cancer cells with mean selectivity indices to human (136) and murine (320) cancer cells. It effectively induces release of DAMPs (CALR, ATP & HMGB1) in CT26 cells facilitating more efficient phagocytosis by J774 macrophages than the FDA drugs or their co-administration. The viability of CT26 cells co-cultured with J774 macrophages and treated with 2 was reduced by 32 % compared to the non-treated cells, suggesting a synergistic antiproliferative effect between the chemical and immune reactions. 2 inhibited in vivo tumor growth in two murine models (LLC and CT26) better than the FDA drugs or their co-administration with significantly lower body weight loss. Mice inoculated with CT26 cells treated with 2 showed slightly better tumor free survival than doxorubicin.


Assuntos
Antineoplásicos , Neoplasias , Pró-Fármacos , Camundongos , Humanos , Animais , Oxaliplatina/farmacologia , Gencitabina , Pró-Fármacos/farmacologia , Pró-Fármacos/uso terapêutico , Morte Celular Imunogênica , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Linhagem Celular Tumoral
5.
Pharmaceutics ; 15(2)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36839999

RESUMO

For a variety of cancer types, platinum compounds are still among the best treatment options. However, their application is limited by side effects and drug resistance. Consequently, multi-targeted platinum(IV) prodrugs that target specific traits of the malignant tissue are interesting new candidates. Recently, cisPt(PhB)2 was synthesized which, upon reduction in the malignant tissue, releases phenylbutyrate (PhB), a metabolically active fatty acid analog, in addition to cisplatin. In this study, we in-depth investigated the anticancer properties of this new complex in cell culture and in mouse allograft experiments. CisPt(PhB)2 showed a distinctly improved anticancer activity compared to cisplatin as well as to PhB alone and was able to overcome various frequently occurring drug resistance mechanisms. Furthermore, we observed that differences in the cellular fatty acid metabolism and mitochondrial activity distinctly impacted the drug's mode of action. Subsequent analyses revealed that "Warburg-like" cells, which are characterized by deficient mitochondrial function and fatty acid catabolism, are less capable of coping with cisPt(PhB)2 leading to rapid induction of a non-apoptotic form of cell death. Summarizing, cisPt(PhB)2 is a new orally applicable platinum(IV) prodrug with promising activity especially against cisplatin-resistant cancer cells with "Warburg-like" properties.

6.
Angew Chem Int Ed Engl ; 62(10): e202217233, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36628505

RESUMO

AuI -carbene and PtIV -AuI -carbene prodrugs display low to sub-µM activity against several cancer cell lines and overcome cisplatin (cisPt) resistance. Linking a cisPt-derived PtIV (phenylbutyrate) complex to a AuI -phenylimidazolylidene complex 2, yielded the most potent prodrug. While in vivo tests against Lewis Lung Carcinoma showed that the prodrug PtIV (phenylbutyrate)-AuI -carbene (7) and the 1 : 1 : 1 co-administration of cisPt: phenylbutyrate:2 efficiently inhibited tumor growth (≈95 %), much better than 2 (75 %) or cisPt (84 %), 7 exhibited only 5 % body weight loss compared to 14 % for 2, 20 % for cisPt and >30 % for the co-administration. 7 was much more efficient than 2 at inhibiting TrxR activity in the isolated enzyme, in cells and in the tumor, even though it was much less efficient than 2 at binding to selenocysteine peptides modeling the active site of TrxR. Organ distribution and laser-ablation (LA)-ICP-TOFMS imaging suggest that 7 arrives intact at the tumor and is activated there.


Assuntos
Antineoplásicos , Pró-Fármacos , Antineoplásicos/química , Fenilbutiratos , Pró-Fármacos/química , Linhagem Celular Tumoral , Cisplatino/química
7.
Dalton Trans ; 51(44): 16824-16835, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36189643

RESUMO

In this work, biologically active α-lipoic acid (ALA) and its isologous 1,2-diselenolane (SeA) and cyclopentyl (CpA) analogues were investigated for their differences in redox potentials, cytotoxicity and ROS production. In addition, the corresponding Pt(IV) complexes comprising ALA (1-4), SeA (5-8) and CpA (9-12) as axial ligands were synthesized. Those Pt(IV) complexes were characterized by NMR spectroscopy, ESI-mass spectrometry and elemental analysis. The cytotoxicity study showed that 1,2-diselenolane containing Pt(IV) (1, 3 and 4) complexes are more cytotoxic than the 1,2-dithiolane analogues (5, 7, and 8) throughout all tested cell lines, intriguingly, cyclopentyl containing species (9, 11 and 12) are the most effective, in some cases even more potent than the parent drug oxaliplatin. Three representative complexes 2, 6 and 10 were further assessed for their redox potentials, reduction with AsA, lipophilicity, cellular accumulation and ROS production. It turned out that the cytotoxicity profile is an overall result of good lipophilicity, high cellular accumulation, and (partially) enhanced ROS generation.


Assuntos
Antineoplásicos , Oxaliplatina/farmacologia , Ligantes , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular Tumoral , Antineoplásicos/química
8.
Chem Biodivers ; 19(10): e202200695, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36026613

RESUMO

α-Lipoic acid, known for its anti-inflammatory and antioxidant activity, represents a promising ligand for Pt(IV) prodrugs. Three new Pt(IV) lipoate complexes were synthesized and characterized by NMR spectroscopy (1 H, 13 C, 195 Pt), mass spectrometry and elemental analysis. Due to the low solubility of the complex containing two axial lipoate ligands, further experiments to examine the biological activity were performed with two Pt(IV) complexes containing just one axial lipoate ligand. Both complexes exhibit anticancer activity and produce reactive oxygen species (ROS) in the cell lines tested. Especially, the monosubstituted complex can be reduced by ascorbic acid and forms adducts with 9-methylguanine (9MeG), which is favorable for the formation of DNA-crosslinks in the cells.


Assuntos
Antineoplásicos , Pró-Fármacos , Ácido Tióctico , Antineoplásicos/química , Antioxidantes , Ácido Ascórbico , Linhagem Celular Tumoral , DNA , Ligantes , Estrutura Molecular , Pró-Fármacos/farmacologia , Pró-Fármacos/química , Espécies Reativas de Oxigênio/metabolismo
9.
J Anim Ecol ; 91(8): 1612-1626, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35603988

RESUMO

The management of sustainable harvest of animal populations is of great ecological and conservation importance. Development of formal quantitative tools to estimate and mitigate the impacts of harvest on animal populations has positively impacted conservation efforts. The vast majority of existing harvest models, however, do not simultaneously estimate ecological and harvest impacts on demographic parameters and population trends. Given that the impacts of ecological drivers are often equal to or greater than the effects of harvest, and can covary with harvest, this disconnect has the potential to lead to flawed inference. In this study, we used Bayesian hierarchical models and a 43-year capture-mark-recovery dataset from 404,241 female mallards Anas platyrhynchos released in the North American midcontinent to estimate mallard demographic parameters. Furthermore, we model the dynamics of waterfowl hunters and habitat, and the direct and indirect effects of anthropogenic and ecological processes on mallard demographic parameters. We demonstrate that density dependence, habitat conditions and harvest can simultaneously impact demographic parameters of female mallards, and discuss implications for existing and future harvest management models. Our results demonstrate the importance of controlling for multicollinearity among demographic drivers in harvest management models, and provide evidence for multiple mechanisms that lead to partial compensation of mallard harvest. We provide a novel model structure to assess these relationships that may allow for improved inference and prediction in future iterations of harvest management models across taxa.


Assuntos
Efeitos Antropogênicos , Ecossistema , Animais , Teorema de Bayes , Patos , Feminino , Dinâmica Populacional
10.
Dalton Trans ; 51(16): 6254-6263, 2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-35373808

RESUMO

Metal ions have unique electrochemical and spectroscopical properties that cannot be attained by purely organic compounds. Most of the metal ions are toxic to humans, but paradoxically, metallodrugs are used in medicine as therapeutics and theranostics. Metallodrugs are eliminated in urine and faeces, and therefore release toxic metals and ligands into aquatic ecosystems, thereby raising concerns regarding environmental risks. The use of metallodrugs based on essential metal ions (i.e., iron, copper and zinc), instead of toxic ions, is a new alternative with minor hazards. Kojic acid is an Asperigillus oryzae metabolite of low toxicity used in the food and cosmetics industries. Its derivatives form stable complexes with iron(III) ions, which bind effectively to DNA and inhibit DNA polymerization. The iron(III)/S2 ligand complexes reduce in vitro colon carcinoma (Caco2) cell viability and significantly decrease the cell number. The kojic acid derivative complexes with iron(III) presented here are an alternative to the currently used platinum complexes in cancer therapy.


Assuntos
Complexos de Coordenação , Neoplasias , Alumínio/química , Complexos de Coordenação/farmacologia , Cobre/química , DNA , Ecossistema , Humanos , Íons , Ferro/química , Ligantes , Pironas
11.
Ann Neurol ; 91(1): 23-32, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34786756

RESUMO

OBJECTIVE: Perfusion imaging identifies anterior circulation stroke patients who respond favorably to endovascular thrombectomy (ET), but its role in basilar artery occlusion (BAO) is unknown. We hypothesized that BAO patients with limited regions of severe hypoperfusion (time to reach maximum concentration in seconds [Tmax] > 10) would have a favorable response to ET compared to patients with more extensive regions involved. METHODS: We performed a multicenter retrospective cohort study of BAO patients with perfusion imaging prior to ET. We prespecified a Critical Area Perfusion Score (CAPS; 0-6 points), which quantified severe hypoperfusion (Tmax > 10) in cerebellum (1 point/hemisphere), pons (2 points), and midbrain and/or thalamus (2 points). Patients were dichotomized into favorable (CAPS ≤ 3) and unfavorable (CAPS > 3) groups. The primary outcome was a favorable functional outcome 90 days after ET (modified Rankin Scale = 0-3). RESULTS: One hundred three patients were included. CAPS ≤ 3 patients (87%) had a lower median National Institutes of Health Stroke Scale score (NIHSS; 12.5, interquartile range [IQR] = 7-22) compared to CAPS > 3 patients (13%; 23, IQR = 19-36; p = 0.01). Reperfusion was achieved in 84% of all patients, with no difference between CAPS groups (p = 0.42). Sixty-four percent of reperfused CAPS ≤ 3 patients had a favorable outcome compared to 8% of nonreperfused CAPS ≤ 3 patients (odds ratio [OR] = 21.0, 95% confidence interval [CI] = 2.6-170; p < 0.001). No CAPS > 3 patients had a favorable outcome, regardless of reperfusion. In a multivariate regression analysis, CAPS ≤ 3 was a robust independent predictor of favorable outcome after adjustment for reperfusion, age, and pre-ET NIHSS (OR = 39.25, 95% CI = 1.34->999, p = 0.04). INTERPRETATION: BAO patients with limited regions of severe hypoperfusion had a favorable response to reperfusion following ET. However, patients with more extensive regions of hypoperfusion in critical brain regions did not benefit from endovascular reperfusion. ANN NEUROL 2022;91:23-32.


Assuntos
Imagem de Perfusão/métodos , Trombectomia , Resultado do Tratamento , Insuficiência Vertebrobasilar/diagnóstico por imagem , Insuficiência Vertebrobasilar/cirurgia , Adulto , Idoso , Estudos de Coortes , Procedimentos Endovasculares/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Neuroimagem/métodos , Reperfusão/métodos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos , Insuficiência Vertebrobasilar/patologia
12.
J Med Chem ; 64(15): 11364-11378, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34342437

RESUMO

"Multi-action" Pt(IV) derivatives of cisplatin with combretastatin A4 (CA4) bioactive ligands that are conjugated to Pt(IV) by carbonate are unique because the ligand (IC50 < 10 nM) is dramatically 1000-folds more cytotoxic than cisplatin in vitro. The Pt(IV)-CA4 prodrugs were as cytotoxic as CA4 itself, indicating that the platinum moiety probably plays an insignificant role in triggering cytotoxicity, suggesting that the Pt(IV)-CA4 complexes act as prodrugs for CA4 rather than as true multi-action prodrugs. In vivo tests (Lewis lung carcinoma) show that ctc-[Pt(NH3)2(PhB)(CA4)Cl2] inhibited tumor growth by 93% compared to CA4 (67%), cisplatin (84%), and 1:1:1 cisplatin/CA4/PhB (85%) while displaying <5% body weight loss compared to cisplatin (20%) or CA4 (10%). In this case, and perhaps with other extremely potent bioactive ligands, platinum(IV) acts merely as a self-immolative carrier triggered by reduction in the cancer cell with only a minor contribution to cytotoxicity.


Assuntos
Antineoplásicos/farmacologia , Anidrase Carbônica IV/metabolismo , Compostos Organoplatínicos/farmacologia , Pró-Fármacos/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Anidrase Carbônica IV/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Cricetulus , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Ligantes , Estrutura Molecular , Compostos Organoplatínicos/síntese química , Compostos Organoplatínicos/química , Pró-Fármacos/síntese química , Pró-Fármacos/química , Proibitinas , Relação Estrutura-Atividade
13.
ChemMedChem ; 16(14): 2188-2191, 2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-33928760

RESUMO

We would like to be able to design Pt(IV) prodrugs that can overcome resistance and minimize side effects. Unlike with the early exploration of Pt(II) anticancer agents where clear structure-activity relationships were defined, even after more than two decades of research on Pt(IV) prodrugs, there is no roadmap that can point us to the holy grail. Despite many excellent rational endeavors, we still have not found the "right" two axial ligands to append to the Pt(IV) derivatives of platinum(II) drugs that will "make platinum great again". So far this proved elusive, indicating that the design of Pt(IV) prodrugs is a difficult and frustrating task. Despite our better understanding of the biological processes and availability of advanced technologies, even our sophisticated rational plans often leave us disappointed and frustrated because at the end of the day, we are not able to outsmart the cancer cells or the mice, and just like Rosenberg, we might need to be rescued by serendipity.


Assuntos
Antineoplásicos/farmacologia , Compostos Organoplatínicos/farmacologia , Pró-Fármacos/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Camundongos , Estrutura Molecular , Compostos Organoplatínicos/síntese química , Compostos Organoplatínicos/química , Pró-Fármacos/síntese química , Pró-Fármacos/química , Relação Estrutura-Atividade
14.
J Inorg Biochem ; 217: 111353, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33477089

RESUMO

Pt(IV) complexes are designed as prodrugs that are intended to overcome resistance. Pt(IV) prodrugs are activated inside cancer cells releasing cytotoxic Pt(II) drugs as well as two axial ligands that can be used to confer favorable pharmacological properties to the prodrug. The ligands can be innocent spectators, cancer targeting agents or bioactive moieties. The choice of axial ligands determines the chemical and pharmacological properties of the prodrugs. Over the years, several approaches were employed in attempts to increase the selectivity of the prodrugs to cancer cells and to utilize multi-action prodrugs to overcome resistance. In this review, we critically examine several of these approaches in order to evaluate the validity of some of the working hypotheses that are driving the current research.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Pró-Fármacos/farmacologia , Animais , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Complexos de Coordenação/uso terapêutico , Reparo do DNA/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores de Histona Desacetilases/farmacologia , Humanos , Neoplasias/tratamento farmacológico , Platina/química , Pró-Fármacos/uso terapêutico
15.
Ecol Evol ; 11(24): 18125-18135, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35003662

RESUMO

The estimation of abundance and distribution and factors governing patterns in these parameters is central to the field of ecology. The continued development of hierarchical models that best utilize available information to inform these processes is a key goal of quantitative ecologists. However, much remains to be learned about simultaneously modeling true abundance, presence, and trajectories of ecological communities.Simultaneous modeling of the population dynamics of multiple species provides an interesting mechanism to examine patterns in community processes and, as we emphasize herein, to improve species-specific estimates by leveraging detection information among species. Here, we demonstrate a simple but effective approach to share information about observation parameters among species in hierarchical community abundance and occupancy models, where we use shared random effects among species to account for spatiotemporal heterogeneity in detection probability.We demonstrate the efficacy of our modeling approach using simulated abundance data, where we recover well our simulated parameters using N-mixture models. Our approach substantially increases precision in estimates of abundance compared with models that do not share detection information among species. We then expand this model and apply it to repeated detection/non-detection data collected on six species of tits (Paridae) breeding at 119 1 km2 sampling sites across a P. montanus hybrid zone in northern Switzerland (2004-2020). We find strong impacts of forest cover and elevation on population persistence and colonization in all species. We also demonstrate evidence for interspecific competition on population persistence and colonization probabilities, where the presence of marsh tits reduces population persistence and colonization probability of sympatric willow tits, potentially decreasing gene flow among willow tit subspecies.While conceptually simple, our results have important implications for the future modeling of population abundance, colonization, persistence, and trajectories in community frameworks. We suggest potential extensions of our modeling in this paper and discuss how leveraging data from multiple species can improve model performance and sharpen ecological inference.

16.
J Med Chem ; 63(22): 13861-13877, 2020 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-33175515

RESUMO

Herein, we describe the synthesis, characterization, and biological properties of Pt(IV) derivatives of cisplatin with estramustine at the first axial position, which is known to disrupt the microtubule assembly and act as an androgen antagonist, and varying the second axial position using an innocent ligand (acetate or hydroxyl) to prepare dual-action and triple-action prodrugs with known inhibitors of histone deacetylase, cyclooxygenase, and pyruvate dehydrogenase kinase. We demonstrate superior antiproliferative activity at submicromolar concentrations of the prodrugs against a panel of cancer cell lines, particularly against prostate cancer cell lines. The results obtained in this study exemplify the complex mode of action of "multiaction" Pt(IV) prodrugs. Interestingly, changing the second axial ligand in the Pt-estramustine complex has a significant effect on the mode of action, suggesting that all three components of the Pt(IV) prodrugs (platinum moiety and axial ligands) contribute to the killing of cells and not just one dominant component.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/química , Estramustina/química , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Antineoplásicos/química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Masculino , Neoplasias da Próstata/patologia , Células Tumorais Cultivadas
17.
Dalton Trans ; 49(23): 7722-7736, 2020 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-32469362

RESUMO

Recent results have confirmed that protection of transplatin from reactions on the path to cancer cells substantially increases their activity, suggesting that such complexes have greater potential than previously thought. In this study we have investigated the use of the platinum(iv) oxidation state and the tetracarboxylate coordination sphere to determine whether these features could impart the same stability to trans-diammineplatinum complexes that they do to cis-diam(m)ineplatinum complexes. The cis complexes exhibit resistance to reduction by l-ascorbate and human blood serum, but are readily reduced inside cancer cells. Studies of reduction monitored by 1H NMR revealed that oxidation of trans-diammineplatinum(ii) complexes does not always result in significant stabilisation, but the complexes trans, trans, trans-[Pt(OAc)4(NH3)2] (OAc = acetate) and trans, trans, trans-[Pt(OPr)2(OAc)2(NH3)2] (OPr = propionate) exhibit second order half-lives of 33 h and 5.9 days respectively in the presence of a ten-fold excess of l-ascorbate. XANES spectroscopy studies of reduction in blood models showed that trans, trans, trans-[Pt(OAc)4(NH3)2] is stable in blood serum for at least 24 hours, but is reduced rapidly in whole blood and was observed to have a half-life of approximately 4 hours in DLD-1 colon cancer cells. Consequently, the tetracarboxylatoplatinum(iv) moiety has the properties required to enable the delivery of trans-diammine platinum complexes to cancer cells.


Assuntos
Compostos Organoplatínicos/farmacologia , Pró-Fármacos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Técnicas Eletroquímicas , Humanos , Estrutura Molecular , Compostos Organoplatínicos/sangue , Compostos Organoplatínicos/química , Oxirredução , Pró-Fármacos/química , Pró-Fármacos/metabolismo , Espectroscopia de Prótons por Ressonância Magnética , Estereoisomerismo , Espectroscopia por Absorção de Raios X
18.
Inorg Chem ; 59(7): 5182-5193, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32207294

RESUMO

Multiaction Pt(IV) prodrugs can overcome resistance associated with the FDA approved Pt(II) drugs like cisplatin. Intracellular reduction of the octahedral Pt(IV) derivatives of cisplatin releases cisplatin and the two axial ligands. When the released axial ligands act synergistically with cisplatin to kill the cancer cells, we have multiaction prodrugs. Most Pt(IV) multiaction prodrugs have bioactive ligands possessing a carboxylate that is conjugated to the Pt(IV) because breaking the Pt(IV)-ligand bond releases the active moiety. As many drugs that act synergistically with cisplatin do not have carboxylates, a major challenge is to prepare multiaction Pt(IV) complexes with drugs that have amino groups or hydroxyl groups such that following reduction, the drugs are released in their active form. Our objective was to prepare multiaction Pt(IV) prodrugs that release bioactive molecules having amino groups. Because we cannot conjugate amino groups to the axial position of Pt(IV), we developed a novel and efficient approach for the synthesis of Pt(IV)-carbamato complexes and demonstrated that following reduction of the Pt(IV), the released carbamates undergo rapid decarboxylation, releasing the free amine, as in the case of the PARP-1 inhibitor 3-aminobenzamide and the amino derivative of the HDAC inhibitor SAHA. Pt(IV)-carbamato complexes are stable in cell culture medium and are reduced by ascorbate. They are reduced slower than their carboxylato and carbonato analogues. We believe that this approach paves the way for preparing novel classes of multiaction Pt(IV) prodrugs with amino containing bioactive molecules that up to now were not accessible.


Assuntos
Antineoplásicos/farmacologia , Carbamatos/farmacologia , Complexos de Coordenação/farmacologia , Pró-Fármacos/farmacologia , Antineoplásicos/síntese química , Benzamidas/farmacologia , Carbamatos/síntese química , Linhagem Celular Tumoral , Cisplatino/farmacologia , Complexos de Coordenação/síntese química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Ligantes , Oxirredução , Platina/química , Pró-Fármacos/síntese química
19.
Angew Chem Int Ed Engl ; 59(18): 7069-7075, 2020 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-32017379

RESUMO

PtII complexes are commonly used to treat cancer. To reduce their side effects and improve their pharmacological properties, PtIV complexes are being developed as prodrug candidates that are activated by reduction in cancer cells. Concomitantly, RuII polypyridine complexes have gained much attention as photosensitizers for use in photodynamic therapy due to their attractive characteristics. In this article, a novel PtIV -RuII conjugate, which combines cancer activated chemotherapy with PDT, is presented. Upon entering the cancer cell, the PtIV centre is reduced to PtII and the axial ligands including the RuII complex and phenylbutyrate are released. As each component has its individual targets, the conjugate exerts a multi-target and multi-action effect with (photo-)cytotoxicity values upon irradiation up to 595 nm in the low nanomolar range in various (drug resistant) 2D monolayer cancer cells and 3D multicellular tumour spheroids.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Platina/farmacologia , Rutênio/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Ensaios de Seleção de Medicamentos Antitumorais , Quimioterapia Combinada , Humanos , Raios Infravermelhos , Estrutura Molecular , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química , Platina/química , Rutênio/química
20.
Inorg Chem ; 58(24): 16676-16688, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31790216

RESUMO

Pt(II) complexes, such as cisplatin and oxaliplatin, are in widespread use as anticancer drugs. Their use is limited by the toxic side effects and the ability of tumors to develop resistance to the drugs. A popular approach to overcome these drawbacks is to use their kinetically inert octahedral Pt(IV) derivatives that act as prodrugs. The most successful Pt(IV) complex in clinical trials to date is satraplatin, cct-[Pt(NH3)(c-hexylamine)Cl2(OAc)2], that upon cellular reduction releases the cytotoxic cis-[Pt(NH3)(c-hexylamine)Cl2]. In an attempt to obtain water-soluble and more effective cytotoxic Pt(IV) complexes, we prepared a series of dual- and triple-action satraplatin analogues, where the equatorial chlorido ligands were replaced with acetates and the axial ligands include innocent and bioactive ligands. Replacement of the chlorides with acetates enhanced the water solubility of the compounds and, with one exception, all of the compounds were very stable in buffer. In general, compounds with one or two axial hydroxido ligands were reduced by ascorbate significantly more quickly than compounds with two axial carboxylates. While replacement of the chlorides with acetates in satraplatin led to a reduction in cytotoxicity, the dual- and triple-action analogues with equatorial acetates had low- to sub-micromolar IC50 values in a panel of eight cancer cells. The triple-action compound cct-[Pt(NH3)(c-hexylamine)(OAc)2(PhB)(DCA)] was active in all cell lines, causing DNA damage that induced cell cycle inhibition and apoptosis. Its good activity against CT26 cells in vitro translated into good in vivo efficacy against the CT26 allograft, an in vivo model with intrinsic satraplatin resistance. This indicates that multiaction Pt(IV) derivatives of diamine dicarboxylates are interesting anticancer drug candidates.

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