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1.
ACS Appl Mater Interfaces ; 12(11): 12609-12617, 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32073826

RESUMO

Glioblastoma multiforme (GBM) is a grade IV astrocytoma, which is the most aggressive form of brain tumor. The standard of care for this disease includes surgery, radiotherapy and temozolomide (TMZ) chemotherapy. Poor accumulation of TMZ at the tumor site, tumor resistance to drug, and dose-limiting bone marrow toxicity eventually reduce the success of this treatment. Herein, we have encapsulated >500 drug molecules of TMZ into the biocompatible protein nanocage, apoferritin (AFt), using a "nanoreactor" method (AFt-TMZ). AFt is internalized by transferrin receptor 1-mediated endocytosis and is therefore able to facilitate cancer cell uptake and enhance drug efficacy. Following encapsulation, the protein cage retained its morphological integrity and surface charge; hence, its cellular recognition and uptake are not affected by the presence of this cargo. Additional benefits of AFt include maintenance of TMZ stability at pH 5.5 and drug release under acidic pH conditions, encountered in lysosomal compartments. MTT assays revealed that the encapsulated agents displayed significantly increased antitumor activity in U373V (vector control) and, remarkably, the isogenic U373M (MGMT expressing TMZ-resistant) GBM cell lines, with GI50 values <1.5 µM for AFt-TMZ, compared to 35 and 376 µM for unencapsulated TMZ against U373V and U373M, respectively. The enhanced potency of AFt-TMZ was further substantiated by clonogenic assays. Potentiated G2/M cell cycle arrest following exposure of cells to AFt-TMZ indicated an enhanced DNA damage burden. Indeed, increased O6-methylguanine (O6-MeG) adducts in cells exposed to AFt-TMZ and subsequent generation of γH2AX foci support the hypothesis that AFt significantly enhances the delivery of TMZ to cancer cells in vitro, overwhelming the direct O6-MeG repair conferred by MGMT. We have additionally encapsulated >500 molecules of the N3-propargyl imidazotetrazine analog (N3P), developed to combat TMZ resistance, and demonstrated significantly enhanced activity of AFt-N3P against GBM and colorectal carcinoma cell lines. These studies support the use of AFt as a promising nanodelivery system for targeted delivery, lysosomal drug release, and enhanced imidazotetrazine potency for treatment of GBM and wider-spectrum malignancies.

2.
J Cell Mol Med ; 24(2): 1750-1759, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31876059

RESUMO

Stomach cancer is the fourth most common cancer worldwide. Identification of novel molecular therapeutic targets and development of novel treatments are critical. Against a panel of gastric carcinoma cell lines, the activity of 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F 203) was investigated. Adopting RT-PCR, Western blot and immunohistochemical techniques, we sought to determine molecular pharmacodynamic (PD) markers of sensitivity and investigate arylhydrocarbon (AhR) receptor-mediated signal transduction activation by 5F 203. Potent (IC50  ≤ 0.09 µmol/L), selective (>250-fold) in vitro antitumour activity was observed in MKN-45 and AGS carcinoma cells. Exposure of MKN-45 cells to 5F 203 triggered cytosolic AhR translocation to nuclei, inducing CYP1A1 (>50-fold) and CYP2W1 (~20-fold) transcription and protein (CYP1A1 and CYP2W1) expression. G2/M arrest and γH2AX expression preceded apoptosis, evidenced by PARP cleavage. In vivo, significant (P < .01) 5F 203 efficacy was observed against MKN-45 and AGS xenografts. In mice-bearing 5F 203-sensitive MKN-45 and 5F 203-insensitive BGC-823 tumours in opposite flanks, CYP1A1, CYP2W1 and γH2AX protein in MKN-45 tumours only following treatment of mice with 5F 203 (5 mg/kg) revealed PD biomarkers of sensitivity. 5F 203 evokes potent, selective antitumour activity in vitro and in vivo in human gastric cancer models. It triggers AhR signal transduction, CYP-catalysed bioactivation to electrophilic species causing lethal DNA double-strand breaks exclusively in sensitive cells. 5F 203 represents a novel therapeutic agent with a mechanism of action distinct from current clinical drugs, exploiting novel molecular targets pertinent to gastric tumourigenesis: AhR, CYP1A1 and CYP2W1. PD markers of 5F 203 sensitivity that could guide patient selection have been identified.

3.
Int J Nanomedicine ; 14: 9525-9534, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31824148

RESUMO

Introduction: Advancement of novel anticancer drugs into clinical use is frequently halted by their lack of solubility, reduced stability under physiological conditions, and non-specific uptake by normal tissues, causing systemic toxicity. Their progress to use in the clinic could be accelerated by the development of new formulations employing suitable and complementary drug delivery vehicles. Methods: A robust method for apoferritin (AFt)-encapsulation of antitumour benzothiazoles has been developed for enhanced activity against and drug delivery to benzothiazole-sensitive cancers. Results: More than 70 molecules of benzothiazole 5F 203 were encapsulated per AFt cage. Post-encapsulation, the size and integrity of the protein cages were retained as evidenced by dynamic light scattering. ToF-SIMS depth profiling using an argon cluster beam confirmed 5F 203 exclusively within the AFt cavity. Improved encapsulation of benzothiazole lysyl-amide prodrugs was achieved (~130 molecules of Phortress per AFt cage). Transferrin receptor 1, TfR1, was detected in lysates prepared from most cancer cell lines studied, contributing to enhanced anticancer potency of the AFt-encapsulated benzothiazoles (5F 203, Phortress, GW 610, GW 608-Lys). Nanomolar activity was demonstrated by AFt-formulations in breast, ovarian, renal and gastric carcinoma cell lines, whereas GI50 >50 µM was observed in non-tumourigenic MRC-5 fibroblasts. Intracellular 5F 203, a potent aryl hydrocarbon receptor (AhR) ligand, and inducible expression of cytochrome P450 (CYP) 1A1 were detected following exposure of sensitive cells to AFt-5F 203, confirming that the activity of benzothiazoles was not compromised following encapsulation. Conclusion: Our results show enhanced potency and selectivity of AFt-encapsulated 5F 203 against carcinomas derived from breast, ovarian, renal, colorectal as well as gastric cancer models, and offer realistic prospects for potential refinement of tumour-targeting and treatment, and merit further in vivo investigations.


Assuntos
Antineoplásicos/farmacologia , Apoferritinas/metabolismo , Sistemas de Liberação de Medicamentos , Tiazóis/farmacologia , Linhagem Celular Tumoral , Sistema Enzimático do Citocromo P-450/metabolismo , Feminino , Humanos , Receptores de Hidrocarboneto Arílico/metabolismo , Tiazóis/química
4.
Nanotechnology ; 30(50): 505102, 2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31509807

RESUMO

We report on the synthesis of water-soluble gold nanoclusters capped with polyethylene glycol (PEG)-based ligands and further functionalized with folic acid for specific cellular uptake. The dihydrolipoic acid-PEG-based ligands terminated with -OMe, -NH2 and -COOH functional groups are produced and used for surface passivation of Au nanoclusters (NCs) with diameters <2 nm. The produced sub 2 nm Au NCs possess long-shelf life and are stable in physiologically relevant environments (temperature and pH), are paramagnetic and biocompatible. The paramagnetism of Au NCs in solution is also reported. The functional groups on the capping ligands are used for direct conjugation of targeting molecules onto Au NCs without the need for post synthesis modification. Folic acid (FA) is attached via an amide group and effectively target cells expressing the folate receptor. The combination of targeting ability, biocompatibility and paramagnetism in FA-functionalized Au NCs is of relevance for their exploitation in nanomedicine for targeted imaging.

5.
Front Oncol ; 9: 485, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31263673

RESUMO

Temozolomide (TMZ) is the standard of care chemotherapeutic agent used in the treatment of glioblastoma multiforme. Cytotoxic O6-methylguaine lesions formed by TMZ are repaired by O6-methyl-guanine DNA methyltransferase (MGMT), a DNA repair protein that removes alkyl groups located at the O6-position of guanine. Response to TMZ requires low MGMT expression and functional mismatch repair. Resistance to TMZ conferred by MGMT, and tolerance to O6-methylguanine lesions conferred by deficient MMR severely limit TMZ clinical applications. Therefore, development of new TMZ derivatives that can overcome TMZ-resistance is urgent. In this study, we investigated the anti-tumor mechanism of action of two novel TMZ analogs: C8-imidazolyl (377) and C8-methylimidazole (465) tetrazines. We found that analogs 377 and 465 display good anticancer activity against MGMT-overexpressing glioma T98G and MMR deficient colorectal carcinoma HCT116 cell lines with IC50 value of 62.50, 44.23, 33.09, and 25.37 µM, respectively. Analogs induce cell cycle arrest at G2/M, DNA double strand break damage and apoptosis irrespective of MGMT and MMR status. It was established that analog 377, similar to TMZ, is able to ring-open and hydrolyze under physiological conditions, and its intermediate product is more stable than MTIC. Moreover, DNA adducts of 377 with calf thymus DNA were identified: N7-methylguanine, O6-methylguanine, N3-methyladenine, N3-methylthymine, and N3-methylcytidine deoxynucleotides. We conclude that C8 analogs of TMZ share a mechanism of action similar to TMZ and are able to methylate DNA generating O6-methylguanine adducts, but unlike TMZ are able at least in part to thwart MGMT- and MMR-mediated resistance.

6.
Nanomedicine ; 20: 102005, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31048084

RESUMO

Listeria innocua DNA binding protein from starved cells (LiDps) belongs to the ferritin family and provides a promising self-assembling spherical 12-mer protein scaffold for the generation of functional nanomaterials. We report the creation of a Gaussia princeps luciferase (Gluc)-LiDps fusion protein, with chemical conjugation of Zinc (II)-protoporphyrin IX (ZnPP) to lysine residues on the fusion protein (giving Gluc-LiDps-ZnPP). The Gluc-LiDps-ZnPP conjugate is shown to generate reactive oxygen species (ROS) via Bioluminescence Resonance Energy Transfer (BRET) between the Gluc (470-490 nm) and ZnPP. In vitro, Gluc-LiDps-ZnPP is efficiently taken up by tumorigenic cells (SKBR3 and MDA-MB-231 breast cancer cells). In the presence of coelenterazine, this construct inhibits the proliferation of SKBR3 due to elevated ROS levels. Following exposure to Gluc-LiDps-ZnPP, migration of surviving SKBR3 cells is significantly suppressed. These results demonstrate the potential of the Gluc-LiDps-ZnPP conjugate as a platform for future development of an anticancer photodynamic therapy agent.

7.
Int J Pharm ; 565: 151-161, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31029659

RESUMO

Herein, an injectable formulation composed of a low molecular weight gelator (LMWG) based hydrogel and drug-loaded polymeric nanocapsules (NCs) is described. The NCs, made of hyaluronic acid and polyglutamic acid and loaded with C14-Gemcitabine (GEM C14), showed a size of 40 and 80 nm and a encapsulation efficiency >90%. These NCs exhibited a capacity to control the release of the encapsulated drug for >1 month. GEM C14-loaded NCs showed activity against various cancer cell lines in vitro; cell growth inhibition by 50% (GI50) values of 15 ±â€¯6, 10 ±â€¯9, 13 ±â€¯3 and 410 ±â€¯463 nM were obtained in HCT 116, MIA PaCa-2, Panc-1 and Panc-1 GEM resistant cell lines respectively. Nanocomposite hydrogels were prepared using the LMWG - N4-octanoyl-2'-deoxycytidine and loaded for the first time with polymeric NCs. 2% and 4% w/v nanocapsule concentrations as compared to 8% w/v NC concentrations with 2% and 3% w/v gelator concentrations gave mechanically stronger gels as determined by oscillatory rheology. Most importantly, the nanocomposite formulation reformed instantly into a gel after injection through a needle. Based on these properties, the nanocomposite gel formulation has potential for the intratumoural delivery of anticancer drugs.


Assuntos
Antineoplásicos/administração & dosagem , Desoxicitidina/análogos & derivados , Hidrogéis/administração & dosagem , Nanocompostos/administração & dosagem , Antineoplásicos/química , Linhagem Celular Tumoral , Desoxicitidina/administração & dosagem , Desoxicitidina/química , Liberação Controlada de Fármacos , Humanos , Ácido Hialurônico/administração & dosagem , Ácido Hialurônico/química , Hidrogéis/química , Injeções , Peso Molecular , Nanocompostos/química , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Ácido Poliglutâmico/administração & dosagem , Ácido Poliglutâmico/química , Reologia
8.
Cancer Lett ; 453: 57-73, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30930233

RESUMO

Natural products possess a significant role in anticancer therapy and many currently-used anticancer drugs are of natural origin. Cerberin (CR), a cardenolide isolated from the fruit kernel of Cerbera odollam, was found to potently inhibit cancer cell growth (GI50 values < 90 nM), colony formation and migration. Significant G2/M cell cycle arrest preceded time- and dose-dependent apoptosis-induction in human cancer cell lines corroborated by dose-and time-dependent PARP cleavage and caspase 3/7 activation, in addition to reduced Bcl-2 and Mcl-1 expression. CR potently inhibited PI3K/AKT/mTOR signalling depleting polo-like kinase 1 (PLK-1), c-Myc and STAT-3 expression. Additionally, CR significantly increased the generation of reactive oxygen species (ROS) producing DNA double strand breaks. Preliminary in silico biopharmaceutical assessment of CR predicted >60% bioavailability and rapid absorption; doses of 1-10 mg/kg CR were predicted to maintain efficacious unbound plasma concentrations (>GI50 value). CR's potent and selective anti-tumour activity, and its targeting of key signalling mechanisms pertinent to tumourigenesis support further preclinical evaluation of this cardiac glycoside.

9.
Cancer Chemother Pharmacol ; 82(6): 913-922, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30182146

RESUMO

Autophagy is a tightly controlled process comprising lysosomal degradation and recycling of cellular proteins and organelles. In cancer, its paradoxical dual role of cytoprotection and cytotoxicity is context-dependent and controversial. Autophagy primarily acts as a mechanism of tumour suppression, by maintenance of genomic integrity and prevention of proliferation and inflammation. This, combined with immune-surveillance capabilities and autophagy's implicated role in cell death, acts to prevent tumour initiation. However, established tumours exploit autophagy to survive cellular stresses in the hostile tumour microenvironment. This can lead to therapy resistance, one of the biggest challenges facing current anti-cancer approaches. Autophagy modulation is an exciting area of clinical development, attempting to harness this fundamental process as an anti-cancer strategy. Autophagy induction could potentially prevent tumour formation and enhance anti-cancer immune responses. In addition, drug-induced autophagy could be used to kill cancer cells, particularly those in which the apoptotic machinery is defective. Conversely, autophagy inhibition may help to sensitise resistant cancer cells to conventional chemotherapies and specifically target autophagy-addicted tumours. Currently, hydroxychloroquine is in phase I and II clinical trials in combination with several standard chemotherapies, whereas direct, deliberate autophagy induction remains to be tested clinically. More comprehensive understanding of the roles of autophagy throughout different stages of carcinogenesis has potential to guide development of novel therapeutic strategies to eradicate cancer cells.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Autofagia/efeitos dos fármacos , Hidroxicloroquina/farmacologia , Neoplasias/tratamento farmacológico , Animais , Autofagia/fisiologia , Ensaios Clínicos como Assunto , Humanos , Neoplasias/imunologia , Neoplasias/patologia , Microambiente Tumoral/efeitos dos fármacos
10.
Medchemcomm ; 9(3): 545-553, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30108945

RESUMO

A series of 3-(benzyl-substituted)-imidazo[5,1-d]-1,2,3,5-tetrazines (13) and related derivatives with 3-heteromethyl groups has been synthesised and screened for growth-inhibitory activity in vitro against two pairs of glioma cell lines with temozolomide-sensitive and -resistant phenotypes dependent on the absence/presence of the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT). In general the compounds had low inhibitory activity with GI50 values >50 µM against both sets of cell lines. Two silicon-containing derivatives, the TMS-methylimidazotetrazine (9) and the SEM-analogue (10), showed interesting differences: compound (9) had a profile very similar to that of temozolomide with the MGMT+ cell lines being 5 to 10-fold more resistant than MGMT- isogenic partners; the SEM-substituted compound (10) showed potency across all cell lines irrespective of their MGMT status.

11.
J Control Release ; 286: 10-19, 2018 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-30016732

RESUMO

The intestinal lymphatic system plays an important role in the pathophysiology of multiple diseases including lymphomas, cancer metastasis, autoimmune diseases, and human immunodeficiency virus (HIV) infection. It is thus an important compartment for delivery of drugs in order to treat diseases associated with the lymphatic system. Lipophilic prodrug approaches have been used in the past to take advantage of the intestinal lymphatic transport processes to deliver drugs to the intestinal lymphatics. Most of the approaches previously adopted were based on very bulky prodrug moieties such as those mimicking triglycerides (TG). We now report a study in which a lipophilic prodrug approach was used to efficiently deliver bexarotene (BEX) and retinoic acid (RA) to the intestinal lymphatic system using activated ester prodrugs. A range of carboxylic ester prodrugs of BEX were designed and synthesised and all of the esters showed improved association with chylomicrons, which indicated an improved potential for delivery to the intestinal lymphatic system. The conversion rate of the prodrugs to BEX was the main determinant in delivery of BEX to the intestinal lymphatics, and activated ester prodrugs were prepared to enhance the conversion rate. As a result, an 4-(hydroxymethyl)-1,3-dioxol-2-one ester prodrug of BEX was able to increase the exposure of the mesenteric lymph nodes (MLNs) to BEX 17-fold compared to when BEX itself was administered. The activated ester prodrug approach was also applied to another drug, RA, where the exposure of the MLNs was increased 2.4-fold through the application of a similar cyclic activated prodrug. Synergism between BEX and RA was also demonstrated in vitro by cell growth inhibition assays using lymphoma cell lines. In conclusion, the activated ester prodrug approach results in efficient delivery of drugs to the intestinal lymphatic system, which could benefit patients affected by a large number of pathological conditions.


Assuntos
Antineoplásicos/administração & dosagem , Bexaroteno/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Mucosa Intestinal/metabolismo , Sistema Linfático/metabolismo , Pró-Fármacos/administração & dosagem , Tretinoína/administração & dosagem , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Bexaroteno/análogos & derivados , Bexaroteno/farmacocinética , Esterificação , Linfonodos/metabolismo , Vasos Linfáticos/metabolismo , Masculino , Pró-Fármacos/química , Pró-Fármacos/farmacocinética , Ratos Sprague-Dawley , Distribuição Tecidual , Tretinoína/análogos & derivados , Tretinoína/farmacocinética
12.
Sci Rep ; 8(1): 10617, 2018 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-30006510

RESUMO

The jerantinine family of Aspidosperma indole alkaloids from Tabernaemontana corymbosa are potent microtubule-targeting agents with broad spectrum anticancer activity. The natural supply of these precious metabolites has been significantly disrupted due to the inclusion of T. corymbosa on the endangered list of threatened species by the International Union for Conservation of Nature. This report describes the asymmetric syntheses of (-)-jerantinines A and E from sustainably sourced (-)-tabersonine, using a straight-forward and robust biomimetic approach. Biological investigations of synthetic (-)-jerantinine A, along with molecular modelling and X-ray crystallography studies of the tubulin-(-)-jerantinine B acetate complex, advocate an anticancer mode of action of the jerantinines operating via microtubule disruption resulting from binding at the colchicine site. This work lays the foundation for accessing useful quantities of enantiomerically pure jerantinine alkaloids for future development.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Alcaloides Indólicos/farmacologia , Tubulina (Proteína)/metabolismo , Antineoplásicos Fitogênicos/síntese química , Linhagem Celular Tumoral , Colchicina/farmacologia , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Espécies em Perigo de Extinção , Química Verde , Humanos , Alcaloides Indólicos/síntese química , Alcaloides Indólicos/química , Alcaloides Indólicos/isolamento & purificação , Microtúbulos/química , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Modelos Moleculares , Quinolinas/química , Quinolinas/isolamento & purificação , Sementes/química , Tabernaemontana/química , Tubulina (Proteína)/química , Moduladores de Tubulina/farmacologia , Voacanga/química
13.
Chemistry ; 24(33): 8325-8330, 2018 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-29604227

RESUMO

1,2-Diazetidin-3-ones are readily accessible, small ring scaffolds that upon functionalization have the potential to produce diverse 3-dimensional structures for drug discovery. Thus, treatment of diazo hydrazides, obtained from simple hydrazides and malonyl half ester derivatives, followed by diazo transfer, with catalytic amounts of rhodium(II) acetate dimer results in intramolecular carbenoid N-H insertion to give 1,2-diazetidin-3-ones. Although subsequent functionalization reactions could be hampered by the lability of the 4-membered ring, a wide range of new derivatives was available by deprotection at N-1, and subsequent amide or urea formation. The structures of four four-membered rings was confirmed by X-ray crystallography; the compounds showed modest growth inhibitory activity in mammary carcinoma cells.


Assuntos
Descoberta de Drogas , Ródio/química , Catálise , Cristalografia por Raios X
14.
ChemMedChem ; 13(11): 1098-1101, 2018 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-29570948

RESUMO

We have synthesized a range of gelators based on the nucleoside analogues gemcitabine and lamivudine, characterizing representative gels from the series using rheology and transmission electron microscopy. Growth inhibition studies of gemcitabine derivatives confirmed the feasibility of these compounds as novel treatments, indicating the potential of nucleoside-based gelators for localized drug delivery.


Assuntos
Desoxicitidina/análogos & derivados , Sistemas de Liberação de Medicamentos , Géis/farmacologia , Lamivudina/farmacologia , Linhagem Celular Tumoral , Desoxicitidina/administração & dosagem , Desoxicitidina/síntese química , Desoxicitidina/química , Desoxicitidina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Géis/síntese química , Géis/química , Humanos , Lamivudina/administração & dosagem , Lamivudina/síntese química , Lamivudina/química , Microscopia Eletrônica de Transmissão , Reologia , Substâncias Viscoelásticas/síntese química , Substâncias Viscoelásticas/química , Substâncias Viscoelásticas/farmacologia
15.
Mol Pharm ; 15(4): 1578-1586, 2018 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-29502421

RESUMO

Low molecular weight gelators (LMWGs) of chemotherapeutic drugs represent a valid alternative to the existing polymer-based formulations used for targeted delivery of anticancer drugs. Herein we report the design and development of novel self-assembling gelators of the antitumor benzothiazole 5F 203 (1). Two different types of derivatives of 1 were synthesized, formed by an amide (2) and a carbamate (3a-3d) linker, respectively, which showed potent in vitro antitumor activity against MCF-7 mammary and IGROV-1 ovarian carcinoma cells. In contrast, MRC-5 fibroblasts were inherently resistant to the above derivatives (GI50 > 10 µM), thus revealing stark selectivity against the malignant cell lines over the nontransformed fibroblasts. Western blots assays demonstrated induction of CYP1A1 by 1 and its derivatives only in sensitive malignant cells (MCF-7), corroborating conservation of a CYP1A1-mediated mechanism of action. The ability to form stable gels under relatively high strains was supported by rheological tests; in addition, their inner morphology was characterized as possessing a crossed-linked nanostructure, with the formation of thick aggregates with variable widths between 1100 and 400 nm and lengths from 8 to 32 µm. Finally, in vitro dissolution studies proved the ability of hydrogel 2 to release 48% of 2 within 80 h, therefore demonstrating its ability to act as a platform for localized delivery.


Assuntos
Antineoplásicos/química , Benzotiazóis/química , Hidrogéis/química , Amidas/química , Carbamatos/química , Linhagem Celular Tumoral , Citocromo P-450 CYP1A1/metabolismo , Feminino , Células HCT116 , Humanos , Células MCF-7 , Nanoestruturas/química , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/metabolismo
16.
J Cell Biochem ; 119(7): 5350-5358, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29331023

RESUMO

The efficacy of temozolomide (TMZ) treatment for cancers is currently limited by inherent or the development of resistance, particularly, but not exclusively, due to the expression of the DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT) in a significant proportion of tumors. We have found that TMZ analog C8-methyl imidazole tetrazine (PMX 465) displayed good anticancer activity against the colorectal carcinoma HCT116 cells which are MGMT-overexpressing and mismatch repair (MMR)-deficient. In this study, we found that PMX 465 could downregulate the expression of MGMT in HCT116 cells at the protein and mRNA levels. We found that PMX 465 could reduce MGMT expression by increasing the binding of wild-type p53 to the MGMT promoter and reducing the binding of Sp1 to the MGMT promoter.


Assuntos
Antineoplásicos Alquilantes/farmacologia , Neoplasias Colorretais/metabolismo , Metilases de Modificação do DNA/metabolismo , Enzimas Reparadoras do DNA/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Temozolomida/análogos & derivados , Temozolomida/farmacologia , Proteínas Supressoras de Tumor/metabolismo , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Regulação para Baixo , Células HCT116 , Humanos , Regiões Promotoras Genéticas , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/genética
17.
Fitoterapia ; 125: 161-173, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29355749

RESUMO

Cardamonin is a natural chalcone that has been shown to exhibit high anticancer activity. In an attempt to discover analogues of cardamonin with enhanced anticancer activity, 19 analogues were synthesized and tested against A549 and HK1 cell lines. Results of the MTS cell viability assay showed that several derivatives possessed cytotoxic activities that were several-fold more potent than cardamonin. SAR analysis showed the importance of the ketone and alkene groups for bioactivity, while substituting cardamonin's phenolic groups with more polar moieties resulted in activity enhancement. As part of the SAR study and further exploration of chemical space, the effect of metal coordination on cytotoxicity was also investigated, but it was only possible to successfully obtain the Cu (II) complex of cardamonin (19). Compound 19 was the most active analogue possessing IC50 values of 13.2µM and 0.7µM against A549 and HK1 cells, corresponding to a 5- and 32-fold increase in activity, respectively. It was also able to significantly inhibit the migration of A549 and HK1 cells. Further mode of action studies have shown that the most active analogue, 19, induced DNA damage resulting in G2/M-phase cell- cycle arrest in both cell lines. These events further led to the induction of apoptosis by the compound via caspase-3/7 and caspase-9 activation, PARP cleavage and downregulation of Mcl-1 expression. Moreover, 19 inhibited the expression levels of p-mTOR and p-4EBP1, which indicated that it exerted its anticancer activity, at least in part, via inhibition of the mTOR signalling pathway.


Assuntos
Apoptose/efeitos dos fármacos , Caspases/metabolismo , Chalconas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Linhagem Celular Tumoral , Chalconas/síntese química , Humanos , Estrutura Molecular , Relação Estrutura-Atividade
18.
Cancer Chemother Pharmacol ; 81(3): 427-441, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29285635

RESUMO

An increasing number of manuscripts focus on the in vitro evaluation of established and novel anti-tumor agents in experimental models. Whilst the design of such in vitro assays is inherently flexible, some of these studies lack the minimum information necessary to critically evaluate their relevance or have been carried out under unsuitable conditions. The use of appropriate and robust methods and experimental design has important implications for generating results that are reliable, relevant, and reproducible. The Pharmacology and Molecular Mechanisms (PAMM) group of the European Organization for Research and Treatment of Cancer (EORTC) is the largest group of academic scientists working on drug development and bundle decades of expertise in this field. This position paper addresses all researchers with an interest in the preclinical and cellular pharmacology of anti-tumor agents and aims at generating basic recommendations for the correct use of compounds to be tested for anti-tumor activity using a range of preclinical cellular models of cancer.


Assuntos
Antineoplásicos/farmacologia , Avaliação Pré-Clínica de Medicamentos , Neoplasias/tratamento farmacológico , Confiabilidade dos Dados , Descoberta de Drogas , Avaliação Pré-Clínica de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos/normas , Europa (Continente) , Humanos
19.
J Cell Biochem ; 118(12): 4526-4535, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28471540

RESUMO

We investigated activity and mechanism of action of two AhR ligand antitumor agents, AFP 464 and 5F 203 on human renal cancer cells, specifically examining their effects on cell cycle progression, apoptosis, and migration. TK-10, SN12C, Caki-1, and ACHN human renal cancer cell lines were treated with AFP 464 and 5F 203. We evaluated cytotoxicity by MTS assays, cell cycle arrest, and apoptosis by flow cytometry and corroborated a mechanism of action involving AhR signal transduction activation. Changes in migration properties by wound healing assays were investigated: 5F 203-sensitive cells show decreased migration after treatment, therefore, we measured c-Met phosphorylation by Western blot in these cells. A 5F 203 induced a decrease in cell viability which was more marked than AFP 464. This cytotoxicity was reduced after treatment with the AhR inhibitor α-NF for both compounds indicating AhR signaling activation plays a role in the mechanism of action. A 5F 203 is sequestered by TK-10 cells and induces CYP1A1 expression; 5F 203 potently inhibited migration of TK-10, Caki-1, and SN12C cells, and inhibited c-Met receptor phosphorylation in TK-10 cells. AhR ligand antitumor agents AFP 464 and 5F 203 represent potential new candidates for the treatment of renal cancer. A 5F 203 only inhibited migration of sensitive cells and c-Met receptor phosphorylation in TK-10 cells. c-Met receptor signal transduction is important in migration and metastasis. Therefore, we consider that 5F 203 offers potential for the treatment of metastatic renal carcinoma. J. Cell. Biochem. 118: 4526-4535, 2017. © 2017 Wiley Periodicals, Inc.


Assuntos
Antineoplásicos/farmacologia , Carcinoma de Células Renais/tratamento farmacológico , Flavonoides/farmacologia , Neoplasias Renais/tratamento farmacológico , Proteínas de Neoplasias/agonistas , Receptores de Hidrocarboneto Arílico/agonistas , Tiazóis/farmacologia , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Humanos , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Proteínas de Neoplasias/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Transdução de Sinais/efeitos dos fármacos
20.
Sci Rep ; 7: 42504, 2017 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-28198434

RESUMO

Precursor mRNA (pre-mRNA) splicing is catalyzed by a large ribonucleoprotein complex known as the spliceosome. Numerous studies have indicated that aberrant splicing patterns or mutations in spliceosome components, including the splicing factor 3b subunit 1 (SF3B1), are associated with hallmark cancer phenotypes. This has led to the identification and development of small molecules with spliceosome-modulating activity as potential anticancer agents. Jerantinine A (JA) is a novel indole alkaloid which displays potent anti-proliferative activities against human cancer cell lines by inhibiting tubulin polymerization and inducing G2/M cell cycle arrest. Using a combined pooled-genome wide shRNA library screen and global proteomic profiling, we showed that JA targets the spliceosome by up-regulating SF3B1 and SF3B3 protein in breast cancer cells. Notably, JA induced significant tumor-specific cell death and a significant increase in unspliced pre-mRNAs. In contrast, depletion of endogenous SF3B1 abrogated the apoptotic effects, but not the G2/M cell cycle arrest induced by JA. Further analyses showed that JA stabilizes endogenous SF3B1 protein in breast cancer cells and induced dissociation of the protein from the nucleosome complex. Together, these results demonstrate that JA exerts its antitumor activity by targeting SF3B1 and SF3B3 in addition to its reported targeting of tubulin polymerization.


Assuntos
Antineoplásicos/farmacologia , Morte Celular/efeitos dos fármacos , Alcaloides Indólicos/farmacologia , Fosfoproteínas/metabolismo , Fatores de Processamento de RNA/metabolismo , Apoptose/efeitos dos fármacos , Neoplasias da Mama , Linhagem Celular Tumoral , Feminino , Técnicas de Silenciamento de Genes , Genômica/métodos , Humanos , Células MCF-7 , Fosfoproteínas/genética , Proteoma , Proteômica/métodos , Processamento de RNA/efeitos dos fármacos , Fatores de Processamento de RNA/genética , Spliceossomos/metabolismo
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