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1.
Nucleic Acids Res ; 48(17): 9710-9723, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32890395

RESUMO

Two DNA repair pathways operate at DNA double strand breaks (DSBs): non-homologous end-joining (NHEJ), that requires two adjacent DNA ends for ligation, and homologous recombination (HR), that resects one DNA strand for invasion of a homologous duplex. Faithful repair of replicative single-ended DSBs (seDSBs) is mediated by HR, due to the lack of a second DNA end for end-joining. ATM stimulates resection at such breaks through multiple mechanisms including CtIP phosphorylation, which also promotes removal of the DNA-ends sensor and NHEJ protein Ku. Here, using a new method for imaging the recruitment of the Ku partner DNA-PKcs at DSBs, we uncover an unanticipated role of ATM in removing DNA-PKcs from seDSBs in human cells. Phosphorylation of DNA-PKcs on the ABCDE cluster is necessary not only for DNA-PKcs clearance but also for the subsequent MRE11/CtIP-dependent release of Ku from these breaks. We propose that at seDSBs, ATM activity is necessary for the release of both Ku and DNA-PKcs components of the NHEJ apparatus, and thereby prevents subsequent aberrant interactions between seDSBs accompanied by DNA-PKcs autophosphorylation and detrimental commitment to Lig4-dependent end-joining.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Quebras de DNA de Cadeia Dupla , Reparo do DNA por Junção de Extremidades/fisiologia , Proteína Quinase Ativada por DNA/metabolismo , Autoantígeno Ku/metabolismo , Proteínas Mutadas de Ataxia Telangiectasia/genética , Camptotecina/farmacologia , Linhagem Celular , Reparo do DNA por Junção de Extremidades/efeitos dos fármacos , DNA Ligase Dependente de ATP/genética , DNA Ligase Dependente de ATP/metabolismo , DNA de Cadeia Simples , Proteína Quinase Ativada por DNA/genética , Humanos , Autoantígeno Ku/genética , Proteína Homóloga a MRE11/genética , Proteína Homóloga a MRE11/metabolismo , Fosforilação , Inibidores da Topoisomerase I/farmacologia
2.
PLoS One ; 15(8): e0228002, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764831

RESUMO

Irinotecan specifically targets topoisomerase I (topoI), and is used to treat various solid tumors, but only 13-32% of patients respond to the therapy. Now, it is understood that the rapid rate of topoI degradation in response to irinotecan causes irinotecan resistance. We have published that the deregulated DNA-PKcs kinase cascade ensures rapid degradation of topoI and is at the core of the drug resistance mechanism of topoI inhibitors, including irinotecan. We also identified CTD small phosphatase 1 (CTDSP1) (a nuclear phosphatase) as a primary upstream regulator of DNA-PKcs in response to topoI inhibitors. Previous reports showed that rabeprazole, a proton pump inhibitor (PPI) inhibits CTDSP1 activity. The purpose of this study was to confirm the effects of rabeprazole on CTDSP1 activity and its impact on irinotecan-based therapy in colon cancer. Using differentially expressing CTDSP1 cells, we demonstrated that CTDSP1 contributes to the irinotecan sensitivity by preventing topoI degradation. Retrospective analysis of patients receiving irinotecan with or without rabeprazole has shown the effects of CTDSP1 on irinotecan response. These results indicate that CTDSP1 promotes sensitivity to irinotecan and rabeprazole prevents this effect, resulting in drug resistance. To ensure the best chance at effective treatment, rabeprazole may not be a suitable PPI for cancer patients treated with irinotecan.


Assuntos
Neoplasias Colorretais/metabolismo , DNA Topoisomerases Tipo I/metabolismo , Rabeprazol/metabolismo , Linhagem Celular Tumoral , Neoplasias do Colo/metabolismo , Neoplasias Colorretais/fisiopatologia , DNA , DNA Topoisomerases Tipo I/fisiologia , Proteína Quinase Ativada por DNA/metabolismo , Resistência a Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/fisiologia , Humanos , Irinotecano/metabolismo , Irinotecano/farmacologia , Fosfoproteínas Fosfatases/antagonistas & inibidores , Fosfoproteínas Fosfatases/metabolismo , Inibidores da Bomba de Prótons/farmacologia , Rabeprazol/farmacologia , Estudos Retrospectivos , Inibidores da Topoisomerase I/farmacologia
3.
Leukemia ; 34(11): 2992-3006, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32572188

RESUMO

Inactivating mutations in TET2 serve as an initiating genetic lesion in the transformation of hematopoietic stem and progenitor cells (HSPCs). Thus, effective therapy for this subset of patients would ideally include drugs that are selectively lethal in TET2-mutant HSPCs, at dosages that spare normal HSPCs. In this study, we tested 129 FDA-approved anticancer drugs in a tet2-deficient zebrafish model and showed that topoisomerase 1 (TOP1)-targeted drugs and PARP1 inhibitors selectively kill tet2-mutant HSPCs. We found that Tet2-deficient murine bone marrow progenitors and CRISPR-Cas9-induced TET2-mutant human AML cells were more sensitive to both classes of drugs compared with matched control cells. The mechanism underlying the selective killing of TET2-mutant blood cells by these drugs was due to aberrantly low levels of tyrosyl-DNA phosphodiesterase 1 (TDP1), an enzyme that is important for removing TOP1 cleavage complexes (TOP1cc). Low TDP1 levels yield sensitivity to TOP1-targeted drugs or PARP1 inhibitors and an inability to remove TOP1 cleavage complexes, leading to DNA double-strand breaks and cell death. The finding that TET2 mutations render HSPCs uniquely vulnerable to disruption of TOP1 and PARP1 activity may therefore represent a unique opportunity to use relatively low dosages of these drugs for the "precision therapy" of TET2-mutant myeloid malignancies.


Assuntos
DNA Topoisomerases Tipo I/metabolismo , Proteínas de Ligação a DNA/genética , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Poli(ADP-Ribose) Polimerase-1/antagonistas & inibidores , Proteínas Proto-Oncogênicas/genética , Mutações Sintéticas Letais , Inibidores da Topoisomerase I/farmacologia , Animais , Animais Geneticamente Modificados , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Genótipo , Humanos , Camundongos , Camundongos Knockout , Fenótipo , Topotecan/farmacologia , Peixe-Zebra
4.
BMC Complement Med Ther ; 20(1): 141, 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32393373

RESUMO

BACKGROUND: The development and growth of colorectal cancer based on constitutive activation of numerous signaling pathways that stimulate proliferation and metastasis. Plant-derived agents excel by targeting multiple aspects of tumor progression. Previous investigations have shown that ginger derivatives- shogaols possess anti-cancer and anti-inflammatory effects. In the present study, we have examined the anti-cancer effects of 6-shogaol alongside with the most widely used chemotherapeutic agents/regimens in the tumor-like microenvironment conditions. METHODS: Cytotoxicity on two colon cancer cell lines (SW480 and SW620) was measured by MTT test. Apoptosisassay, immunocytochemical and Western blotting analysis for autophagy and apoptosis detection were performed. RESULTS: Here, we report that 6-shogaol by itself or in combination with chemotherapeutic agents/regimens exerted a cytotoxic effect on CRC cells. Cell death might be linked with the activation of autophagy and apoptosis-related pathways. In the tumor-like microenvironment, which is characterized by hypoxia and glucose starvation, 6-shogaol with chemotherapeutics is significantly more potent than conventional chemotherapy alone. CONCLUSIONS: Collectively, our data suggest that the addition of 6-shogaol to established chemotherapeutic regimens could potentially be a remarkable therapeutic strategy for colorectal cancer.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Catecóis/farmacologia , Neoplasias do Colo/patologia , Fluoruracila/farmacologia , Irinotecano/farmacologia , Oxaliplatina/farmacologia , Antineoplásicos/farmacologia , Hipóxia Celular , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Quimioterapia Combinada , Humanos , Imunossupressores/farmacologia , Inibidores da Topoisomerase I/farmacologia
5.
Molecules ; 25(3)2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32033066

RESUMO

The incidence of gastrointestinal cancers is increasing every year. Irinotecan (CPT-11), a drug used in the treatment of colorectal cancer and gastric cancer, is metabolized by carboxylesterases to an active metabolite, SN-38, which is more cytotoxic. CAPE (caffeic acid phenethyl ester) is an active component of propolis, which has a high antibacterial, antiviral, and antineoplastic potential. This study analyses the impact of CAPE on the cytotoxic (MTT assay), genotoxic (comet assay) and proapoptotic (caspase-3/7 activity) potential of irinotecan and its metabolite SN-38 in cultures of gastrointestinal neoplastic cells (HCT116, HT29, AGS). Cytotoxicity and genotoxicity activities of these compounds were carried out in comparison with human peripheral blood lymphocytes (PBLs) in vitro. The antioxidant potential of CAPE was investigated in relation H2O2-induced oxidative stress in the both neoplastic cells and PBLs. CAPE expressed cytotoxic, genotoxic, and pro-apoptotic activity against AGS, HCT116, and HT29 tumor cells. CAPE, in the presence of different concentrations of irinotecan or SN38, decreased the cytotoxicity, genotoxicity, and pro-apoptotic activity in these cell lines, but it has no such action on normal human peripheral blood lymphocytes.


Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Ácidos Cafeicos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Irinotecano/farmacologia , Álcool Feniletílico/análogos & derivados , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citotoxinas/farmacologia , Dano ao DNA/efeitos dos fármacos , Sinergismo Farmacológico , Células HCT116 , Células HT29 , Humanos , Peróxido de Hidrogênio/toxicidade , Irinotecano/análogos & derivados , Linfócitos/efeitos dos fármacos , Mutagênicos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Álcool Feniletílico/farmacologia , Própole/farmacologia , Inibidores da Topoisomerase I/farmacologia
6.
Alkaloids Chem Biol ; 83: 1-112, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32098648

RESUMO

Lamellarins are marine alkaloids containing fused 14-phenyl-6H-[1]benzopyrano[4',3':4,5]pyrrolo[2,1-a]isoquinoline or non-fused 3,4-diarylpyrrole-2-carboxylate ring systems. To date, more than 50 lamellarins have been isolated from a variety of marine organisms, such as mollusks, tunicates, and sponges. Many of them, especially fused type I lamellarins, exhibit impressive biological activity, such as potent cytotoxicity, topoisomerase I inhibition, protein kinases inhibition, and anti-HIV-1 activity. Due to their useful biological activity and limited availability from natural sources, a number of synthetic methods have been developed. In this chapter, we present an updated and comprehensive review on lamellarin alkaloids summarizing their isolation, synthesis, and biological activity.


Assuntos
Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Fármacos Anti-HIV/farmacologia , Antineoplásicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Pirróis/isolamento & purificação , Pirróis/farmacologia , Inibidores da Topoisomerase I/farmacologia , Alcaloides/síntese química , Alcaloides/química , Animais , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/química , Fármacos Anti-HIV/isolamento & purificação , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Humanos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/isolamento & purificação , Pirróis/síntese química , Pirróis/química , Inibidores da Topoisomerase I/síntese química , Inibidores da Topoisomerase I/química , Inibidores da Topoisomerase I/isolamento & purificação
7.
Inorg Chem ; 59(5): 3304-3311, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32064865

RESUMO

The water-compatible optically pure metallohelices made by self-assembly of simple nonpeptidic organic components around Fe(II) ions are now recognized as a distinct subclass of helicates that exhibit similar architecture to some natural cationic antimicrobial peptides. Notably, a new series of metallohelices was recently shown to exhibit biological activity, displaying high, structure-dependent activity against bacteria. It is also important that, thanks to their properties, such metallohelices can exhibit specific interactions with biomacromolecules. Here, following our prior report on the metallohelices that have high, structure-dependent activity against bacteria, we investigated the interactions of the series of iron(II) metallohelices with DNA, which is a potential pharmacological target of this class of coordination compounds. The results obtained with the aid of biophysical and molecular biology methods show that the investigated metallohelices accumulate in eukaryotic cells and that a significant fraction of the metallohelices accumulates in the cell nucleus, allowing them to interact also with nuclear DNA. Additionally, we have demonstrated that some metallohelices have a high affinity to DNA and are able to condense/aggregate DNA molecules more efficiently than conventional DNA-condensing agents, such as polyamines. Moreover, this capability of the metallohelices correlates with their efficiency to inhibit DNA-related enzymatic activities, such as those connected with DNA transcription, catalysis of DNA relaxation by DNA topoisomerase I, and cleavage by restriction enzymes.


Assuntos
Núcleo Celular/química , DNA Topoisomerases Tipo I/metabolismo , DNA/antagonistas & inibidores , Compostos Ferrosos/farmacologia , Inibidores da Topoisomerase I/farmacologia , Núcleo Celular/metabolismo , DNA/genética , DNA/metabolismo , Compostos Ferrosos/síntese química , Compostos Ferrosos/química , Células HCT116 , Humanos , Estrutura Molecular , Fenômenos Ópticos , Inibidores da Topoisomerase I/síntese química , Inibidores da Topoisomerase I/química
8.
Cancer Lett ; 473: 130-138, 2020 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-31904486

RESUMO

All-trans retinoic acid (ATRA) is known to be a potent inhibitor of FLT3-ITD acute myeloid leukemia (AML) cells, although the exact mechanism remains unclear. In this work, we report that ATRA causes fatal mitotic catastrophe in FLT3-ITD AML cells by degrading Chk1 kinase, and therefore preventing DNA damage repair. In order to explore a further enhancement in the inhibitory effect of ATRA on FLT3-ITD AML cells, we investigated the suitability of a combination of ATRA and DNA damage drug SN38. In vitro experiments showed that this combinatorial approach effectively inhibited the proliferation of FLT3-ITD cells and induced cell apoptosis in AML. In vivo experiments confirmed that the combination could substantially improve the anti-tumor effect of SN38. Taken together, our results indicate that ATRA down-regulates Chk1 in FLT3-ITD AML cells, and the combination of ATRA and SN38 significantly improves the anti-tumor effect of either ATRA or SN38 when used alone.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Quinase 1 do Ponto de Checagem/antagonistas & inibidores , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Leucemia Mieloide Aguda/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Tretinoína/farmacologia , Adulto , Idoso , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Quinase 1 do Ponto de Checagem/metabolismo , Pré-Escolar , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Irinotecano/farmacologia , Irinotecano/uso terapêutico , Leucemia Mieloide Aguda/sangue , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Masculino , Camundongos , Pessoa de Meia-Idade , Mitose/efeitos dos fármacos , Cultura Primária de Células , Inibidores de Proteínas Quinases/uso terapêutico , Sequências de Repetição em Tandem/genética , Inibidores da Topoisomerase I/farmacologia , Inibidores da Topoisomerase I/uso terapêutico , Tretinoína/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto , Tirosina Quinase 3 Semelhante a fms/genética
9.
Cell Rep ; 30(4): 1235-1245.e4, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31995761

RESUMO

DNA-protein crosslinks (DPCs) are a frequent form of DNA lesion and are strongly inhibitive in diverse DNA transactions. Despite recent developments, the biochemical detection of DPCs remains a limiting factor for the in-depth mechanistic understanding of DPC repair. Here, we develop a sensitive and versatile assay, designated ARK, for the quantitative analysis of DPCs in cells. ARK uses sequential chaotropic and detergent-based isolation of DPCs and substantially enhances sample purity, resulting in a 5-fold increase in detection sensitivity and a 10-fold reduction in background reading. We validate the ARK assay with genetic mutants with established deficiencies in DPC repair and demonstrate its robustness by using common DPC-inducing reagents, including formaldehyde, camptothecin, and etoposide. In addition, we show that the Fanconi anemia pathway contributes to the repair of DPCs. Thus, ARK is expected to facilitate various studies aimed at understanding both fundamental biology and translational applications of DNA-protein crosslink repair.


Assuntos
Reagentes para Ligações Cruzadas/farmacologia , Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Camptotecina/farmacologia , Reparo do DNA/genética , Etoposídeo/farmacologia , Anemia de Fanconi/genética , Anemia de Fanconi/metabolismo , Técnicas de Inativação de Genes , Técnicas Genéticas , Células HeLa , Humanos , Inibidores da Topoisomerase I/farmacologia
10.
Nat Prod Res ; 34(3): 378-384, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30623670

RESUMO

A new prenylated indole alkaloid, named paraherquamide J (1), together with four known compounds (2-5), were isolated from the mangrove rhizosphere soil-derived fungus Penicillium janthinellum HK1-6. The planar structure and relative configuration of 1 were determined by detailed analysis of the spectroscopic data especially the NOESY spectrum. The absolute configuration of 1 was determined by ECD spectra. Compound 2 was first isolated as a natural product and named as paraherquamide K. All isolated metabolites were evaluated for their antibacterial, topoisomerase I (topo I) inhibitory activities and lethality towards brine shrimp Artemia salina.


Assuntos
Antibacterianos/isolamento & purificação , Indolizinas/isolamento & purificação , Penicillium/química , Compostos de Espiro/isolamento & purificação , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Artemia/efeitos dos fármacos , Alcaloides Indólicos/química , Alcaloides Indólicos/isolamento & purificação , Alcaloides Indólicos/farmacologia , Indolizinas/toxicidade , Estrutura Molecular , Prenilação , Rizosfera , Compostos de Espiro/toxicidade , Inibidores da Topoisomerase I/química , Inibidores da Topoisomerase I/isolamento & purificação , Inibidores da Topoisomerase I/farmacologia
11.
Cancer Chemother Pharmacol ; 85(1): 225-229, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31707444

RESUMO

PURPOSE: The purpose of this study was to determine the importance of UGT1A1 activity on the metabolism and pharmacokinetics of a releasable PEG ~ SN-38 conjugate, PLX038A. Irinotecan (CPT-11) is converted to the topoisomerase 1 inhibitor SN-38 by first-pass hepatic metabolism and is converted to its glucuronide SN-38G by UGT1A1. With diminished UGT1A1 activity, the high liver exposure to SN-38 can cause increased toxicity of CPT-11. In contrast, releasable PEG ~ SN-38 conjugates-such as PLX038-release SN-38 in the vascular compartment, and only low levels of SN-38 are expected to enter the liver by transport through the OATP1B1 transporter. METHODS: We measured CPT-11 and PLX038A metabolites in plasma and bile, and determined pharmacokinetics of PLX038A in UGT1A-deficient and replete rats. RESULTS: Compared to CPT-11, treatment of rats with PLX038A results in very low levels of biliary SN-38 and SN-38G, a low flux through UGT1A, and a low SN-38G/SN-38 ratio in plasma. Further, the pharmacokinetics of plasma PLX038A and SN-38 in rats deficient in UGT1A is unchanged compared to normal rats. CONCLUSIONS: The disposition of PEGylated SN-38 is independent of UGT1A activity in rats, and PLX038 may find utility in full-dose treatment of patients who are UGT1A1*28 homozygotes or have metastatic disease with coincidental or incidental liver dysfunction.


Assuntos
Camptotecina/análogos & derivados , Regulação da Expressão Gênica/efeitos dos fármacos , Glucuronatos/farmacologia , Glucuronosiltransferase/metabolismo , Irinotecano/farmacologia , Polietilenoglicóis/química , Pró-Fármacos/farmacologia , Inibidores da Topoisomerase I/farmacologia , Animais , Bile/metabolismo , Camptotecina/farmacocinética , Camptotecina/farmacologia , Glucuronatos/farmacocinética , Irinotecano/farmacocinética , Fígado/metabolismo , Pró-Fármacos/farmacocinética , Ratos , Ratos Gunn , Distribuição Tecidual , Inibidores da Topoisomerase I/farmacocinética
12.
Biochem Pharmacol ; 171: 113716, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31751535

RESUMO

Melanoma is one of the most aggressive malignancies. Drug resistance and toxicity limits the clinical efficacy of melanoma chemotherapeutic drugs such as dacarbazine. Therefore, the development of chemotherapeutic agents for melanoma treatment is urgently needed. RJT-101 significantly inhibits the proliferation of melanoma cells, however has low cytotoxicity to non-malignant cells. RJT-101 induces apoptosis, DNA damage, and G2/M phase arrest, as a consequent, attenuates tumor growth, lung metastasis in vivo as well as prolongs survival of tumor bearing mice. RJT-101 could block topoisomerase I (Top1) activity as well as induce its degradation through proteasome system. Interestingly, Top1 is over-expressed in melanoma cells, compared to non-malignant cells. Knock down of Top1 suppresses melanoma cells growth and induces apoptosis and DNA damage in melanoma cells. RJT-101 effectively inhibits melanoma cells (including vemurafenib-resistant melanoma cells) proliferation in vitro and in vivo through the induction of DNA damage and apoptosis by inhibiting of Top1, indicating RJT-101 warrants further clinical evaluation.


Assuntos
Antineoplásicos/farmacologia , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Dano ao DNA/efeitos dos fármacos , Melanoma/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Inibidores da Topoisomerase I/farmacologia , Animais , Antineoplásicos/química , Camptotecina/química , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , DNA Topoisomerases Tipo I/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , Melanoma/genética , Melanoma/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Nus , Estrutura Molecular , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Inibidores da Topoisomerase I/química , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
13.
J Med Chem ; 63(2): 696-713, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31880942

RESUMO

Inspired by the natural product evodiamine, a novel antitumor indolopyrazinoquinazolinone scaffold was designed by scaffold hopping. Structure-activity relationship studies led to the discovery of compound 15j, which shows low nanomolar inhibitory activity against the HCT116 cell line. Further antitumor mechanism studies indicated that compound 15j acted by the dual inhibition of topoisomerase 1 and tubulin and induced apoptosis with G2 cell-cycle arrest. The quaternary ammonium salt of compound 15j (compound 15js) exhibited excellent in vivo antitumor activity (TGI = 66.6%) in the HCT116 xenograft model with low toxicity. Indolopyrazinoquinazolinone derivatives represent promising multitargeting antitumor leads for the development of novel antitumor agents.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Quinazolinas/química , Quinazolinas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Desenho de Fármacos , Fase G2/efeitos dos fármacos , Células HCT116 , Humanos , Camundongos , Relação Estrutura-Atividade , Inibidores da Topoisomerase I/síntese química , Inibidores da Topoisomerase I/farmacologia , Inibidores da Topoisomerase II/síntese química , Inibidores da Topoisomerase II/farmacologia , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Sci Rep ; 9(1): 18067, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31792297

RESUMO

Camptothecin (CPT), a natural alkaloid isolated from Camptotheca acuminata Decne, is found to show potential insecticidal activities with unique action mechanisms by targeting at DNA-topoisomease I (Top1) complex and inducing cell apoptosis. To improve the efficacy against insect pests, two camptothecin (CPT) derivatives were synthesized through introducing two functional groups, 2-nitroaminoimidazoline and 1-chloro-2-isocyanatoethane by esterification reaction. The insecticidal activities of these two derivatives were evaluated at contact toxicity, cytotoxicity and topoisomerase I (Top1) inhibitory activities comparing with CPT and hydroxyl-camptothecin (HCPT). Results showed that compound a, synthesized by introducing 2-nitroaminoimidazoline to CPT, apparently increased contact toxicity to the third larvae of beet armyworm, Spodoptera exigua, and cytotoxicity to IOZCAS-Spex-II cells isolated from S. exigua. However, the inhibition on DNA relaxation activity of Top1 was reduced to less than 5 percentage even at high concentrations (50 and 100 µM). For introducing 1-chloro-2-isocyanatoethane to HCPT, the contact toxicity, cytotoxicity and Top1 inhibitory activity of synthesized compound b were increased significantly compared to CPT and HCPT. These results suggested that both synthesized compounds possessed high efficacy against S. exigua by targeting at Top1 (compound b) or novel mechanism of action (compound a).


Assuntos
Camptotecina/farmacologia , Proteínas de Insetos/antagonistas & inibidores , Inseticidas/farmacologia , Spodoptera/efeitos dos fármacos , Inibidores da Topoisomerase I/farmacologia , Animais , Camptotecina/análogos & derivados , Camptotecina/síntese química , DNA Topoisomerases Tipo I/metabolismo , Proteínas de Insetos/metabolismo , Inseticidas/síntese química , Spodoptera/enzimologia , Inibidores da Topoisomerase I/síntese química
15.
BMC Cancer ; 19(1): 1158, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31783818

RESUMO

BACKGROUND: Camptothecin (CPT) and its derivatives are currently used as second- or third-line treatment for patients with endocrine-resistant breast cancer (BC). These drugs convert nuclear enzyme DNA topoisomerase I (TOP1) to a cell poison with the potential to damage DNA by increasing the half-life of TOP1-DNA cleavage complexes (TOP1cc), ultimately resulting in cell death. In small and non-randomized trials for BC, researchers have observed extensive variation in CPT response rates, ranging from 14 to 64%. This variability may be due to the absence of reliable selective parameters for patient stratification. BC cell lines may serve as feasible models for generation of functional criteria that may be used to predict drug sensitivity for patient stratification and, thus, lead to more appropriate applications of CPT in clinical trials. However, no study published to date has included a comparison of multiple relevant parameters and CPT response across cell lines corresponding to specific BC subtypes. METHOD: We evaluated the levels and possible associations of seven parameters including the status of the TOP1 gene (i.e. amplification), TOP1 protein expression level, TOP1 activity and CPT susceptibility, activity of the tyrosyl-DNA phosphodiesterase 1 (TDP1), the cellular CPT response and the cellular growth rate across a representative panel of BC cell lines, which exemplifies three major BC subtypes: Luminal, HER2 and TNBC. RESULTS: In all BC cell lines analyzed (without regard to subtype classification), we observed a significant overall correlation between growth rate and CPT response. In cell lines derived from Luminal and HER2 subtypes, we observed a correlation between TOP1 gene copy number, TOP1 activity, and CPT response, although the data were too limited for statistical analyses. In cell lines representing Luminal and TNBC subtypes, we observed a direct correlation between TOP1 protein abundancy and levels of enzymatic activity. In all three subtypes (Luminal, HER2, and TNBC), TOP1 exhibits approximately the same susceptibility to CPT. Of the three subtypes examined, the TNBC-like cell lines exhibited the highest CPT sensitivity and were characterized by the fastest growth rate. This indicates that breast tumors belonging to the TNBC subtype, may benefit from treatment with CPT derivatives. CONCLUSION: TOP1 activity is not a marker for CPT sensitivity in breast cancer.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Neoplasias da Mama/enzimologia , Camptotecina/farmacologia , DNA Topoisomerases Tipo I/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Inibidores da Topoisomerase I/farmacologia , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , DNA Topoisomerases Tipo I/genética , Feminino , Dosagem de Genes , Expressão Gênica , Humanos , Diester Fosfórico Hidrolases/metabolismo
16.
Anal Chem ; 91(23): 14927-14935, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31710202

RESUMO

Cancer drug resistance mechanisms such as tumor heterogeneity and adaptable feedback loops are prevalent issues facing cancer therapy development. Drug resistance can be unique to a cancer type and, most importantly, to each individual cancer patient. Consequently, testing different dosages and therapeutics directly on each individual patient sample (i.e., tumor and cancer cells) has compelling advantages compared to large scale in vitro drug testing and is a step toward personalized drug selection and effective treatment development. Recently, microfluidic-based chemo-sensitivity assays on patient biopsies have been proposed. Despite their novelty, these platforms usually rely on optical labels, optical equipment, or complex microfabricated channel geometries and structures. In this work, we proposed a novel lab on a chip platform capable of real-time and continuous screening of drug efficacy on (cancer) cell subpopulations without the need of labels or bulky readout optical equipment. In this platform, several label-free and rapid techniques have been implemented for the precise capturing of cells of interest in parallel with the real-time measurement and characterization of the effectiveness of candidate therapeutic agents. To demonstrate the utility of the platform, the effect of an apoptotic inducer, topoisomerase I inhibitor, 7-ethyl-10-hydrocamptothecin (SN38) on human colorectal carcinoma cancer cells (HCT 116) was used as a study model. Additionally, electrical results were optically verified to examine the continuous measurements of the biological mechanisms, specifically, apoptosis and necrosis, during therapeutic agent characterizations. The proposed device is a versatile platform which can also be easily redesigned for the automated and arrayed analysis of cell-drug interaction down to the single cell level. Our platform is another step toward enabling the personalized screening of drug efficacy on individual patients' samples that potentially leads to a better understanding of drug resistance and the optimization of patients' treatments.


Assuntos
DNA Topoisomerases Tipo I/genética , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Irinotecano/farmacologia , Dispositivos Lab-On-A-Chip , Inibidores da Topoisomerase I/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , DNA Topoisomerases Tipo I/metabolismo , Monitoramento de Medicamentos/métodos , Impedância Elétrica , Células HCT116 , Humanos , Modelos Biológicos , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Neoplasias/genética , Neoplasias/patologia , Medicina de Precisão
17.
Int J Mol Sci ; 20(21)2019 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-31717797

RESUMO

In the present study, a series of 4-acyloxy robustic acid derivatives were synthesized and characterized for evaluation of their anti-cancer activity. The structures of these derivatives were elucidated by mass spectra (MS) nuclear magnetic resonance spectra (NMR). The single-crystal X-ray diffraction structure of one of these compounds was obtained, for further validation of the target compound structures. The anticancer activities of the target products were evaluated against human leukemic cells HL-60, human non-small cell lung carcinoma cells A-549, human hepatic carcinoma cells SMMC-7721, human hepatocellular carcinoma cells HepG2, and human cervical carcinoma cells Hela. Three compounds among them exhibited potent in-vitro cytotoxicity and excellent DNA topoisomerase I inhibitory activity, even at 0.1 mM concentrations. The most noteworthy observation was the minor toxicity of two of these compounds to normal cells, with an activity similar to the positive control in cancerous cells. A Surflex-Dock docking study was performed to investigate the topoisomerase I activity of all compounds. Of all the other compounds, the most sensitive compound was selected for further investigation of its effect on apoptosis induction and cell cycle regulation in HL-60 cells. Our results suggest that the anticancer effects of these compounds can be attributed to their pharmacological effects on topoisomerase I, cell apoptosis, and cell cycle. These findings suggest that robustic acid derivatives could be used as potential antitumor drugs.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Isoflavonas/química , Piranocumarinas/síntese química , Piranocumarinas/farmacologia , Células A549 , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Células Cultivadas , DNA Topoisomerases Tipo I/efeitos dos fármacos , Dalbergia/química , Ensaios de Seleção de Medicamentos Antitumorais , Células HL-60 , Células HeLa , Células Hep G2 , Humanos , Concentração Inibidora 50 , Isoflavonas/farmacologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Piranocumarinas/química , Piranocumarinas/uso terapêutico , Inibidores da Topoisomerase I/síntese química , Inibidores da Topoisomerase I/química , Inibidores da Topoisomerase I/farmacologia
18.
BMC Vet Res ; 15(1): 405, 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31706354

RESUMO

BACKGROUND: Canine leishmaniasis is a zoonotic disease caused by Leishmania infantum, being the dogs one of the major reservoirs of human visceral leishmaniasis. DNA topology is a consolidated target for drug discovery. In this regard, topoisomerase IB - one of the enzymes controlling DNA topology - has been poisoned by hundreds of compounds that increase DNA fragility and cell death. Aromathecins are novel molecules with a multiheterocyclic ring scaffold that have higher stability than camptothecins. RESULTS: Aromathecins showed strong activity against both forms of L. infantum parasites, free-living promastigotes and intra-macrophagic amastigotes harbored in ex vivo splenic explant cultures obtained from infected BALB/c mice. However, they prevented the relaxation activity of leishmanial topoisomerase IB weakly, which suggests that the inhibition of topoisomerase IB partially explains the antileishmanial effect of these compounds. The effect of aromathecins was also studied against a strain resistant to camptothecin, and results suggested that the trafficking of these compounds is not through the ABCG6 transporter. CONCLUSIONS: Aromathecins are promising novel compounds against canine leishmaniasis that can circumvent potential resistances based on drug efflux pumps.


Assuntos
Antiprotozoários/farmacologia , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Leishmania infantum/efeitos dos fármacos , Inibidores da Topoisomerase I/farmacologia , Animais , Técnicas de Cultura de Células , DNA Topoisomerases Tipo I/efeitos dos fármacos , DNA Topoisomerases Tipo I/metabolismo , Feminino , Leishmania infantum/enzimologia , Leishmania infantum/crescimento & desenvolvimento , Estágios do Ciclo de Vida/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Proteínas de Protozoários/antagonistas & inibidores , Baço/parasitologia
19.
Sci Rep ; 9(1): 15464, 2019 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-31664047

RESUMO

Pharmacokinetics of SN-38 in patients with end-stage kidney disease (ESKD) is partially varied because of fluctuations in transporters expression and/or function by high protein bound-uremic toxins concentration. The fluctuations may induce variations in anticancer drugs sensitivity to cancer cells. We aimed to clarify the variations in sensitivity of SN-38 to cancer patients with ESKD and investigate this mechanism, by human colon cancer cells exposed to uremic serum residue. LS180 cells were exposed to normal or uremic serum residue (LS/NSR or LS/USR cells) for a month. IC50 values of SN-38 in LS/NSR or LS/USR cells were calculated from viability of each cells treated SN-38. mRNA expression and intracellular SN-38 accumulation was evaluated by RT-PCR and HPLC-fluorescence methods, respectively. The IC50 value in LS/USR cells was higher than that in LS/NSR cells. Organic anion transporter polypeptide (OATP) 2B1 mRNA expression was lower in LS/USR cells than in LS/NSR cells, and SN-38 accumulation in LS/USR cells was lower than that in LS/NSR cells. Only co-treatment baicalin, which is OATP2B1 inhibitor, almost negated the difference in SN-38 accumulation between LS/NSR and LS/USR. Anticancer effects of substrates of OATP2B1, such as SN-38, were reduced in ESKD patients at the same plasma substrate concentration.


Assuntos
Irinotecano/farmacologia , Transportadores de Ânions Orgânicos/antagonistas & inibidores , Inibidores da Topoisomerase I/farmacologia , Uremia/sangue , Linhagem Celular Tumoral , Células HEK293 , Humanos , Irinotecano/farmacocinética , Falência Renal Crônica/metabolismo , Inibidores da Topoisomerase I/farmacocinética
20.
Sci Rep ; 9(1): 14171, 2019 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-31578425

RESUMO

Bisbenzimidazoles with terminal alkynyl linkers, selective inhibitors of bacterial topoisomerase I, have been evaluated using bacterial cytological profiling (BCP) to ascertain their mechanism of action and screened for synergism to improve Gram-negative bacterial coverage. Principal component analysis of high throughput fluorescence images suggests a dual-mechanism of action affecting DNA synthesis and cell membrane integrity. Fluorescence microscopy of bacteria challenged with two of the alkynyl-benzimidazoles revealed changes in the cellular ultrastructure that differed from topoisomerase II inhibitors including induction of spheroplasts and membrane lysis. The cytoskeleton recruitment enzyme inhibitor A22 in combination with one of the alkynyl-benzimidazoles was synergistic against Acinetobacter baumannii and Escherichia coli. Gram-positive coverage remained unchanged in the A22-alkynyl bisbenzimidazole combination. Efflux inhibitors were not synergistic, suggesting that the Gram-negative outer membrane was a significant barrier for alkynyl-bisbenzimidazole uptake. Time-kill assays demonstrated the A22-bisbenzimidazole combination had a similar growth inhibition curve to that of norfloxacin in E.coli. Bisbenzimidazoles with terminal alkynyl linkers likely impede bacterial growth by compromising cell membrane integrity and by interfering with DNA synthesis against Gram-positive pathogens and in the synergistic combination against Gram-negative pathogens including E. coli and multidrug-resistant A. baumanii.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Bisbenzimidazol/análogos & derivados , Escherichia coli/efeitos dos fármacos , Inibidores da Topoisomerase I/farmacologia , Antibacterianos/química , Bisbenzimidazol/farmacologia , Membrana Celular/efeitos dos fármacos , Sinergismo Farmacológico , Inibidores da Topoisomerase I/química
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