RESUMO
Glycation is a common non-enzymatic reaction between proteins and sugars, which gives rise in the human body to the formation of advanced glycation end products (AGEs). These modifications impacts both extra and intracellular proteins, leading to cells and tissues dysfunctions. In the skin, accumulation of AGEs leads to aesthetic consequences, wrinkles, dark spots and yellowish skin tone, as it can be seen in diabetic patients. Consequently, there is a growing dermatological interest to find compounds able to eliminate AGEs accumulated in skin. In this context, a method has been developed to detect and quantify intracellular glycation in human dermal fibroblasts. After cultivation of fibroblasts, cell lysates were injected in an HPLC system coupled with a fluorescence detector in by-pass mode. The system allows the simultaneous measurement of global AGEs and particular pentosidine amounts using two sets of wavelengths in a single run of 1â¯min. The immunocytochemistry approach was used to valid the HPLC analysis data. The method developed was able to quantify changes in global AGEs and pentosidine content in cells in response to glyoxal treatment. Fibroblasts treated with 500⯵M of glyoxal for 48â¯h showed a significant 2.3-fold and 2.6-fold increase in the content of AGEs and pentosidine respectively compared to control cells. As an application, a screening of natural extracts have been done and the method allowed identifying extracts able to significantly reduce the amount of pentosidine in fibroblasts (-32%). These extracts act as deglycation agents of interest in the field of dermatology and cosmetology.
Assuntos
Cromatografia Líquida/métodos , Fibroblastos/citologia , Produtos Finais de Glicação Avançada/análise , Microscopia de Fluorescência/métodos , Pele/citologia , Extratos Celulares/química , Células Cultivadas , Feminino , Glicosilação , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos TestesRESUMO
The mTOR is a central regulator of cell growth and is highly activated in cancer cells to allow rapid tumor growth. The use of mTOR inhibitors as anticancer therapy has been approved for some types of tumors, albeit with modest results. We recently reported the synthesis of ICSN3250, a halitulin analogue with enhanced cytotoxicity. We report here that ICSN3250 is a specific mTOR inhibitor that operates through a mechanism distinct from those described for previous mTOR inhibitors. ICSN3250 competed with and displaced phosphatidic acid from the FRB domain in mTOR, thus preventing mTOR activation and leading to cytotoxicity. Docking and molecular dynamics simulations evidenced not only the high conformational plasticity of the FRB domain, but also the specific interactions of both ICSN3250 and phosphatidic acid with the FRB domain in mTOR. Furthermore, ICSN3250 toxicity was shown to act specifically in cancer cells, as noncancer cells showed up to 100-fold less sensitivity to ICSN3250, in contrast to other mTOR inhibitors that did not show selectivity. Thus, our results define ICSN3250 as a new class of mTOR inhibitors that specifically targets cancer cells.Significance: ICSN3250 defines a new class of mTORC1 inhibitors that displaces phosphatidic acid at the FRB domain of mTOR, inducing cell death specifically in cancer cells but not in noncancer cells. Cancer Res; 78(18); 5384-97. ©2018 AACR.
Assuntos
Neoplasias/metabolismo , Ácidos Fosfatídicos/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Técnicas de Cocultura , Fibroblastos/metabolismo , Células HCT116 , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Humanos , Células K562 , Camundongos , Modelos Moleculares , Simulação de Dinâmica Molecular , Conformação Proteica , Inibidores de Proteínas Quinases/farmacologiaRESUMO
Frequent alteration of upstream proto-oncogenes and tumor suppressor genes activates mechanistic target of rapamycin (mTOR) and causes cancer. However, the downstream effectors of mTOR remain largely elusive. Here we report that brain-expressed X-linked 2 (BEX2) is a novel downstream effector of mTOR. Elevated BEX2 in Tsc2(-/-) mouse embryonic fibroblasts, Pten(-/-) mouse embryonic fibroblasts, Tsc2-deficient rat uterine leiomyoma cells, and brains of neuronal specific Tsc1 knock-out mice were abolished by mTOR inhibitor rapamycin. Furthermore, BEX2 was also increased in the liver of a hepatic specific Pten knock-out mouse and the kidneys of Tsc2 heterozygous deletion mice, and a patient with tuberous sclerosis complex (TSC). mTOR up-regulation of BEX2 was mediated in parallel by both STAT3 and NF-κB. BEX2 was involved in mTOR up-regulation of VEGF production and angiogenesis. Depletion of BEX2 blunted the tumorigenesis of cells with activated mTOR. Therefore, enhanced STAT3/NF-κB-BEX2-VEGF signaling pathway contributes to hyperactive mTOR-induced tumorigenesis. BEX2 may be targeted for the treatment of the cancers with aberrantly activated mTOR signaling pathway.
Assuntos
Carcinogênese , Proteínas do Tecido Nervoso/fisiologia , Serina-Treonina Quinases TOR/fisiologia , Animais , Células Cultivadas , Humanos , Neoplasias Renais/etiologia , Neoplasias Renais/patologia , Camundongos , NF-kappa B/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , RNA Interferente Pequeno/genética , Fator de Transcrição STAT3/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Regulação para CimaRESUMO
The three ayurvedic medicinal plants, Withania somnifera, Emblica officinalis, and Bacopa monnieri, were extracted by high-pressure static extraction using the Zippertex(®) technology. The extracts were mixed to reach quantifiable amounts of active compounds identified by high-pressure liquid chromatography-mass spectrometry (HPLC-MS) analysis. The mixture of extracts was incubated with resting cells of the fungus Beauveria bassiana ATCC 7159. The fermentation promoted the fluidization of the starting dense mixture, while HPLC monitoring evidenced the disappearance of glucogallin from E. officinalis extract and the concomitant increase in gallic acid content. Topical exposure of the chick embryo chorioallantoic membrane (CAM) to the nonfermented extract led to the extensive necrosis and destruction of the treated membrane. However, the fermented extract was shown to be free of any toxicity. Furthermore, compared with the untreated CAM, the fermented sample reduced CAM vascularization, suggesting its antiangiogenic potency. The innocuity of the fermented extract was demonstrated using the in vivo LD50 test, the morphological examination of internal organs of treated rats, as well as the evaluation of blood biomarkers of liver damage (aspartate aminotransferase and alanine aminotransferase). The fermented extract was developed as a nutraceutical antiangiogenic treatment of age-related macular degeneration and commercialized in an oral form named Ethnodyne-Visio™.
Assuntos
Inibidores da Angiogênese/farmacologia , Bacopa , Fermentação , Degeneração Macular/patologia , Phyllanthus emblica , Extratos Vegetais/farmacologia , Withania , Animais , Beauveria/metabolismo , Embrião de Galinha , Membrana Corioalantoide/efeitos dos fármacos , Suplementos Nutricionais , Feminino , Fígado/efeitos dos fármacos , Fígado/enzimologia , Degeneração Macular/tratamento farmacológico , Masculino , Neovascularização Patológica/prevenção & controle , Fitoterapia , Ratos WistarRESUMO
We developed a new robust reduction-responsive polymersome based on the amphiphilic block copolymer PEG-SS-PAChol. The stability and robustness were achieved by the smectic physical cross-linking of cholesterol-containing liquid crystal polymer PAChol in the hydrophobic layer. The reduction-sensitivity was introduced by the disulfide bridge (-S-S-) that links the hydrophilic PEG block and the hydrophobic PAChol block. We used a versatile synthetic strategy based on atom transfer radical polymerization (ATRP) to synthesize the reduction-responsive amphiphilic block copolymers. The reductive cleavage of the disulfide bridge in the block copolymers was first evidenced in organic solution. The partial destruction of PEG-SS-PAChol polymersomes in the presence of a reducing agent was then demonstrated by cryo-electron microscopy. Finally, the calcein release from PEG-SS-PAChol polymersomes triggered by glutathione (GSH) was observed both in PBS suspension and in vitro inside the macrophage cells. High GSH concentrations (≥35 mM in PBS or artificially enhanced in macrophage cells by GSH-OEt pretreatment) and long incubation time (in the order of hours) were, however, necessary to get significant calcein release. These polymersomes could be used as drug carriers with very long circulation profiles and slow release kinetics.
Assuntos
Colesterol/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Polietilenoglicóis/química , Succinimidas/química , Animais , Linhagem Celular , Colesterol/administração & dosagem , Portadores de Fármacos/administração & dosagem , Macrófagos/efeitos dos fármacos , Camundongos , Polietilenoglicóis/administração & dosagem , Succinimidas/administração & dosagemRESUMO
A series of N-methyl-diarylamines 2 was designed and synthesized as a novel class of CA-4 and isoCA-4 analogues. Compounds 2b and 2m showed excellent antiproliferative activity with mean GI50 values at a nanomolar level in a diverse set of human cancer cells. These compounds also inhibited tubulin assembly at a micromolar range, arrested the cellular cycle in the G2/M phase and induced apoptosis at very low concentrations. Preliminary in vitro results revealed that 2b and 2m displayed substantial efficacy as potent antivascular agents. Docking studies indicates that these lead compounds showed a binding mode similar to those observed with isoCA-4 at the colchicine binding site of tubulin.
Assuntos
Antineoplásicos/farmacologia , Compostos Aza/farmacologia , Bibenzilas/farmacologia , Descoberta de Drogas , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Compostos Aza/síntese química , Compostos Aza/química , Bibenzilas/síntese química , Bibenzilas/química , Sítios de Ligação/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HCT116 , Humanos , Células K562 , Modelos Moleculares , Estrutura Molecular , Fenol , Ovinos , Relação Estrutura-Atividade , Tubulina (Proteína)/metabolismoRESUMO
A concise and efficient synthetic route for preparation of four ganglioside GM3 analogues was described. The key step is a highly regioselective and stereoselective α-sialylation from a suitably protected glycoside acceptor with a sialyl xanthate to provide the sialo-oligosaccharide in good yield. The cytotoxic properties of the synthetic gangliosides were evaluated against normal human keratinocytes and human HCT116 and K562 cancer cells. Two of them exhibited good antiproliferative activity and displayed a better cytotoxicity against cancer cell than HaCaT normal cell.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Gangliosídeo G(M3)/análogos & derivados , Gangliosídeo G(M3)/farmacologia , Ácido N-Acetilneuramínico/química , Ácido N-Acetilneuramínico/farmacologia , Antineoplásicos/síntese química , Linhagem Celular , Linhagem Celular Tumoral , Citotoxinas/síntese química , Citotoxinas/química , Citotoxinas/farmacologia , Gangliosídeo G(M3)/síntese química , Humanos , Queratinócitos/efeitos dos fármacos , Ácido N-Acetilneuramínico/síntese química , Neoplasias/tratamento farmacológico , Neoplasias/patologiaRESUMO
The natural tetrapeptide acetyl-N-Ser-Asp-Lys-Pro (AcSDKP) is generated from the N-terminus of thymosin-ß4 through enzymatic cleavage by prolyl oligopeptidase (POP). AcSDKP regulation of proliferation of different cells is implicated in hematopoiesis and angiogenesis. This tetrapeptide present in almost all cells was recently detected at elevated concentrations in neoplastic diseases. However, previously reported in vitro and in vivo studies indicate that AcSDKP does not contribute to the pathogenesis of cancers. Here we show that exogenous AcSDKP exerts no effect on the proliferation of actively dividing malignant cells. Using S17092, a specific POP inhibitor (POPi), to suppress the biosynthesis of AcSDKP in U87-MG glioblastoma cells characterized by high intracellular levels of this peptide, we found that all tested doses of POPi resulted in an equally effective depletion of AcSDKP, which was not correlated with the dose-dependent decreases in the proliferation rate of treated cells. Interestingly, addition of exogenous AcSDKP markedly reversed the reduction in the proliferation of U87-MG cells treated with the highest dose of POPi, and this effect was associated with activation of the phosphatidylinositol-3 kinase (PI3K)/Akt pathway. However, extracellular-regulated protein kinase (ERK) activation was unaltered by S17092 and AcSDKP co-treatment. Knockdown of individual PI3K catalytic subunits revealed that p110α and p110ß contributed differently to AcSDKP regulation of U87-MG cell proliferation. Disruption of p110α expression by small interfering RNA (siRNA) abrogated AcSDKP-stimulated Akt phosphorylation, whereas knockdown of p110ß expression exhibited no such effect. Our findings indicate for the first time that the PI3KCA/Akt pathway mediates AcSDKP regulation of cell proliferation and suggest a role for this ubiquitous intracellular peptide in cell survival.
Assuntos
Proteínas Nucleares/metabolismo , Oligopeptídeos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Expressão Gênica , Humanos , Oligopeptídeos/genética , Oligopeptídeos/farmacologia , Fosforilação/efeitos dos fármacos , Prolil Oligopeptidases , Serina Endopeptidases/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
The first total synthesis of laxaphycin B was accomplished through stepwise automated Solid Phase Peptide Synthesis (SPPS), leading to the structural revision of its stereochemistry especially with regard to the configuration of one of the two 3-hydroxyleucines of this cyclic dodecapeptide of marine origin. The analogous Lyngbyacyclamide A was obtained by an extension of this synthesis.
Assuntos
Peptídeos Cíclicos/síntese química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Peptídeos Cíclicos/química , Técnicas de Síntese em Fase Sólida , EstereoisomerismoRESUMO
Thermoresponsive behavior of different kinds of polymersomes was studied using small angle neutron scattering (SANS), transmission electron microscopy (TEM), and proton nuclear magnetic resonance ((1)H NMR). The polymersomes were made of block copolymers containing a 2000 Da polyethylene glycol (PEG) as a hydrophilic block and either a liquidlike polymer (e.g., PBA: polybutylacrylate), a solidlike polymer (PS: polystyrene), or a liquid crystalline (LC) polymer as a hydrophobic block. Structural changes in polymersomes are driven in all cases by the critical dehydration temperature of PEG corona, which is closely related to the chemical structure and chain mobility of the hydrophobic block. No structural changes occur upon heating from 25 to 75 °C in the liquidlike polymersomes where the critical dehydration temperature of PEG should be higher than 75 °C. In contrast, glassy PEG-b-PS polymersomes and LC polymersomes show structural changes around 55 °C, which corresponds to the critical dehydration temperature of PEG in those block copolymers. Furthermore, the structural changes depend on the properties of the hydrophobic layer. Glassy PEG-b-PS polymersomes aggregate together above 55 °C, but the bilayer membrane is robust enough to remain intact. This aggregation is reversible, and rather separate polymersomes are recovered upon cooling. However, LC polymersomes display drastic and irreversible structural changes when heated above â¼55 °C. These changes are dependent on the LC structures of the hydrophobic layer. Nematic LC polymersomes turn into thick-walled capsules, whereas smectic LC polymersomes collapse into dense aggregates. As these drastic and irreversible changes decrease or remove the inner compartment volume of the vesicle, LC polymersomes can be used for thermal-responsive controlled release, as shown by a study of calcein release. Finally, toxicity studies proved that LC polymersomes were noncytotoxic and had no effect on cell morphology.
Assuntos
Acrilatos/química , Polietilenoglicóis/química , Poliestirenos/química , Temperatura , Linhagem Celular Tumoral , Humanos , Estrutura MolecularRESUMO
A series of novel benzoxepins 6 was designed and prepared as rigid-isoCA-4 analogs according to a convergent strategy using the coupling of N-tosylhydrazones with aryl iodides under palladium catalysis. The most potent compound 6b, having the greatest resemblance to CA-4 and isoCA-4 displayed antiproliferative activity at nanomolar concentrations against various cancer cell lines and inhibited tubulin assembly at a micromolar range. In addition, benzoxepin 6b led to the arrest of HCT116, K562, H1299 and MDA-MB231 cancer cell lines in the G2/M phase of the cell cycle, and strongly induced apoptosis at low concentrations. Docking studies demonstrated that benzoxepin 6b adopt an orientation similar to that of isoCA-4 at the colchicine binding site on ß-tubulin.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Benzoxepinas/farmacologia , Desenho de Fármacos , Estilbenos/farmacologia , Antineoplásicos Fitogênicos/síntese química , Antineoplásicos Fitogênicos/química , Apoptose/efeitos dos fármacos , Benzoxepinas/síntese química , Benzoxepinas/química , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HCT116 , Humanos , Modelos Moleculares , Estrutura Molecular , Estilbenos/síntese química , Estilbenos/química , Relação Estrutura-AtividadeRESUMO
The synthesis and structure-activity relationships associated with a series of 1,1-diarylethylene tubulin polymerization inhibitors 3 and 4 are described. The key step for their preparation involves a palladium-catalyzed coupling of N-arylsulfonylhydrazones with aryl halides, thus providing flexible and convergent access to tri- and tetrasubstituted 1,1-diarylolefins 3 and 4 related to isocombretastatin A-4 (isoCA-4). These compounds have been evaluated for tubulin polymerization inhibitory activity as well as for cytotoxic activity. The most potent compounds are 1,1-diaryl-2-methoxyethylenes 4b, 4d and 4e having a trisubstituted double bond. They exhibited good antiproliferative activity against various human cancer cell lines (GI(50) = 8-80 nM). Compounds 4b and 4e strongly inhibited tubulin polymerization with IC(50) values of 2 and 3 µM, respectively, and induced cell cycle arrest in the G(2)/M phase in the K562 cell line. Docking studies in the colchicine binding site of tubulin allowed identification of residues most likely to interact with these inhibitors and explain their potent anti-tubulin activity.
Assuntos
Alcenos/química , Antineoplásicos Fitogênicos/síntese química , Antineoplásicos Fitogênicos/farmacologia , Estilbenos/farmacologia , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologia , Tubulina (Proteína)/metabolismo , Antineoplásicos Fitogênicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Estilbenos/síntese química , Estilbenos/química , Relação Estrutura-Atividade , Moduladores de Tubulina/síntese químicaRESUMO
A novel series of dihydronaphtalene, tetrahydronaphtalene and naphtalene derivatives as restricted analogues of isoCA-4 were designed, synthesized and evaluated for their anticancer properties. High cell growth inhibition against four tumour cell lines was observed at a nanomolar level with dihydronaphtalenes 1d, e and 1h, tetrahydronaphtalene 2c and naphtalene 3c. Structure-activity relationships are also considered. These compounds exhibited a significant inhibitory activity toward tubulin polymerization (IC(50) = 2-3 µM), comparable to that of isoCA-4. The effect of the lead compounds 1e and 2c on the cancer cells tested was associated with cell cycle arrest in the G(2)/M phase. Docking studies reveal that these compounds showed a binding mode similar to those observed with their non-constraint isoCA-4 and isoerianin congeners.
Assuntos
Benzeno/química , Bibenzilas/química , Clorofenóis/química , Conformação Molecular , Naftalenos/química , Naftalenos/farmacologia , Peptídeos Cíclicos/química , Multimerização Proteica/efeitos dos fármacos , Moduladores de Tubulina/farmacologia , Tubulina (Proteína)/química , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Humanos , Modelos Moleculares , Naftalenos/síntese química , Naftalenos/toxicidade , Fenol , Estrutura Quaternária de Proteína , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/química , Moduladores de Tubulina/toxicidadeRESUMO
We present a method that allows patterning cells and shear flow conditions for endothelial cell based assays. This method is novel in combining (1) cell culture on the surface of a substrate both topographically and chemically patterned; (2) multi-shear flow assays after covering the cell substrate with a microfluidic cover plate containing microchannels of different channel widths, and (3) conventional immunostaining assays after removal of the cover plate. This method has the advantage of performing cell cultures and immunoassays in standard cell biology environments with open access, facilitating the formation of confluent cell layers and the observation of cell responses to shear-flow and drug stimulations. To obtain multi-shear stress conditions, a single channel with stepwise increasing channel widths was patterned on the surfaces of both the substrate and the microfluidic cover plate. As results, we observed excellent viability of endothelial cells in the whole range of applied shear stresses (0-25 dyn cm(-2)) and shear stress dependent cytoskeleton remoulding, activation of von Willebrand factor (vWF), and re-organisation of angiogenesis factors such as tetra peptide acetyl-Ser-Asp-Lys-Pro (AcSDKP) of endothelial cells. To validate this approach for drug analysis, we also studied drug effects under shear stress conditions. Our results indicate that the drug effect of combretastatin A-4, an anti-tumour vascular targeting drug, could be significantly enhanced under shear flow conditions.
Assuntos
Indutores da Angiogênese/metabolismo , Células Endoteliais/efeitos dos fármacos , Técnicas Analíticas Microfluídicas/métodos , Oligopeptídeos/metabolismo , Estilbenos/farmacologia , Células Cultivadas , Citoesqueleto , Células Endoteliais/citologia , Fluorimunoensaio , Humanos , Técnicas Analíticas Microfluídicas/instrumentação , Resistência ao Cisalhamento , Fator de von Willebrand/metabolismoRESUMO
A novel class of isocombretastatin A-4 (isoCA-4) analogues with modifications at the 3'-position of the B-ring by replacement with C-linked substituents was studied. Exploration of the structure-activity relationships of theses analogues led to the identification of several compounds that exhibit excellent antiproliferative activities in the nanomolar concentration range against H1299, MDA-MB231, HCT116, and K562 cancer cell lines; they also inhibit tubulin polymerization with potency similar to that of isoCA-4. 1,1-Diarylethylenes 8 and 17, respectively with (E)-propen-3-ol and propyn-3-ol substituents at the 3'-position of the B-ring, proved to be the most active in this series. Both compounds led to the arrest of various cancer cell lines at the G(2) /M phase of the cell cycle and strongly induced apoptosis. Docking of compounds 8 and 17 in the colchicine binding site indicated that their C3' substituents guide the positioning of the B-ring in a manner different from that observed for isoCA-4.
Assuntos
Anisóis/química , Antineoplásicos/química , Estirenos/química , Anisóis/síntese química , Anisóis/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Sítios de Ligação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Simulação por Computador , Humanos , Neoplasias , Estrutura Terciária de Proteína , Relação Estrutura-Atividade , Estirenos/síntese química , Estirenos/farmacologia , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologiaRESUMO
The cytotoxic activity of a series of 23 new isoerianin derivatives with modifications on both the A and B rings was studied. Several compounds exhibited excellent antiproliferative activity at nanomolar concentrations against a panel of human cancer cell lines. The most cytotoxic compound, isoerianin (3), strongly inhibits tubulin polymerization in the micromolar range. Moreover, isoerianin leads to G2/M phase cell-cycle arrest in H1299 and K562 cancer cells, and strongly induces apoptosis. Isoerianin also disrupts the vessel-like structures formed by human umbilical vein endothelial cells (HUVECs) inâ vitro, suggesting that this compound may act as a vascular disrupting agent. It clearly appears that in this compound series, the 1,1-ethane bridge encountered in isoerianin derivatives can replace the 1,2-ethane bridge of natural erianin with no loss of activity. This reinforces the bioisosteric replacement approach in the combretastatin series previously reported by our research group.
Assuntos
Antineoplásicos/química , Bibenzilas/química , Antineoplásicos/uso terapêutico , Antineoplásicos/toxicidade , Bibenzilas/uso terapêutico , Bibenzilas/toxicidade , Sítios de Ligação , Divisão Celular , Linhagem Celular Tumoral , Simulação por Computador , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Ensaios de Seleção de Medicamentos Antitumorais , Fase G2 , Humanos , Conformação Molecular , Neoplasias/tratamento farmacológico , Fenol , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/química , Moduladores de Tubulina/uso terapêutico , Moduladores de Tubulina/toxicidadeRESUMO
Fast and reproducible quantification of thymosins ß4 and ß10 in different cell cultures was achieved by ultra high performance liquid chromatography coupled to mass spectrometry. We demonstrated that cancer cell lines all exhibit a higher amount of Tß10 compared to control cells, whereas the level of Tß4 is drastically depending on cell lines.
RESUMO
The natural tetrapeptide acetyl-ser-asp-lys-pro (AcSDKP) is formed in vivo by enzymatic cleavage of the N terminus of thymosin beta4 by prolyl oligopeptidase (POP). Recently, AcSDKP was shown to promote angiogenesis. Because of the critical role of neovascularization in cancer development, the levels of AcSDKP and POP activity in a number of different malignant tissues were investigated. Our studies revealed that AcSDKP levels were markedly elevated in neoplastic diseases including hematologic malignancies and solid neoplasms. Consistent with this finding, the enhanced activity of POP was also detected in all analyzed specimens of cancer tissues. Both these novel findings are in concert with the previously reported overexpression of thymosin beta4 in a large variety of malignant tumors and with its potential role in cancerogenesis. The physiological relevance of these findings awaits further studies; however, our first results strongly suggest a key role for AcSDKP in the pathogenesis of cancer.
Assuntos
Dipeptídeos/metabolismo , Neoplasias/metabolismo , Oligopeptídeos/fisiologia , Serina Endopeptidases/metabolismo , Animais , Fenômenos Bioquímicos , Camundongos , Neoplasias/sangue , Neoplasias/enzimologia , Neovascularização Patológica , Prolil Oligopeptidases , TimosinaRESUMO
BACKGROUND: Aberrant expression of cyclin D1 is a common feature in multiple myeloma (MM) and always associated with mantle cell lymphoma (MCL). CCND1 gene is alternatively spliced to produce two cyclin D1 mRNA isoforms which are translated in two proteins: cyclin D1a and cyclin D1b. Both isoforms are present in MM cell lines and primary cells but their relative role in the tumorigenic process is still elusive. RESULTS: To test the tumorigenic potential of cyclin D1b in vivo, we generated cell clones derived from the non-CCND1 expressing MM LP-1 cell line, synthesizing either cyclin D1b or cyclin K, a structural homolog and viral oncogenic form of cyclin D1a. Immunocompromised mice injected s.c. with LP-1K or LP-1D1b cells develop tumors at the site of injection. Genome-wide analysis of LP-1-derived cells indicated that several cellular processes were altered by cyclin D1b and/or cyclin K expression such as cell metabolism, signal transduction, regulation of transcription and translation. Importantly, cyclin K and cyclin D1b have no major action on cell cycle or apoptosis regulatory genes. Moreover, they impact differently cell functions. Cyclin K-expressing cells have lost their migration properties and display enhanced clonogenic capacities. Cyclin D1b promotes tumorigenesis through the stimulation of angiogenesis. CONCLUSIONS: Our study indicates that cyclin D1b participates into MM pathogenesis via previously unrevealed actions.
Assuntos
Ciclina D1/metabolismo , Ciclinas/metabolismo , Mieloma Múltiplo/metabolismo , Animais , Ciclo Celular/fisiologia , Linhagem Celular , Movimento Celular/fisiologia , Separação Celular , Embrião de Galinha , Ciclina D1/genética , Ciclinas/genética , Feminino , Citometria de Fluxo , Humanos , Immunoblotting , Imuno-Histoquímica , Camundongos , Camundongos Nus , Mieloma Múltiplo/genética , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The cytotoxic activities of 23 new isocombretastatin A derivatives with modifications on the B-ring were investigated. Several compounds exhibited excellent antiproliferative activity at nanomolar concentrations against a panel of human cancer cell lines. Compounds isoFCA-4 (2 e), isoCA-4 (2 k) and isoNH(2)CA-4 (2 s) were the most cytotoxic, and strongly inhibited tubulin polymerization with IC(50) values of 4, 2 and 1.5 microM, respectively. These derivatives were found to be 10-fold more active than phenstatin and colchicine with respect to growth inhibition but displayed similar activities as tubulin polymerization inhibitors. In addition, cell cycle arrest in the G(2)/M phase and subsequent apoptosis was observed in three cancer cell lines when treated with these compounds. The disruptive effect of 2 e, 2 k and 2 s on the vessel-like structures formed by human umbilical vein endothelial cells (HUVEC) suggest that these compounds may act as vascular disrupting agents. Both compounds 2 k and 2 s have the potential for further prodrug modification and development as vascular disrupting agents for treatment of solid tumors.