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1.
DNA Cell Biol ; 39(1): 69-77, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31702387

RESUMO

Chemoresistance is one of the major obstacles for cancer therapy. Abnormal expression of long noncoding RNAs (lncRNAs) was broadly implicated in chemoresistance of multiple cancers. This study was aimed to investigate the function of urothelial cancer associated 1 (UCA1) in multidrug resistance of retinoblastoma and its potential molecular mechanism. In this study, we observed that UCA1 was significantly upregulated in chemoresistant retinoblastoma tissues and multidrug resistant retinoblastoma cell lines and predicted an unfavorable overall survival. Functionally, knockdown of UCA1 remarkably inhibited proliferation and sensitized retinoblastoma cells to multiple chemotherapy drugs, including vincristine (VCR), carboplatin (CBP), cisplatin (DDP), VP-16 (etoposide), and 5-fluorouracil (5-Fu). Mechanistic studies demonstrated that UCA1 functioned as a miRNA sponge to increase stathmin 1 (STMN1) expression through sponging miR-513a-5p. In addition, silence of miR-513a-5p or STMN1 overexpression could partly reverse UCA1 knockdown-induced inhibitory effects on proliferation and multidrug resistance of retinoblastoma cells. Overall, this study is the first to demonstrate that UCA1 plays a critical role in retinoblastoma chemoresistance, and UCA1 may serve as a potential diagnostic biomarker and therapeutic target of retinoblastoma.


Assuntos
Proliferação de Células/genética , Resistência a Múltiplos Medicamentos/genética , MicroRNAs/genética , RNA Longo não Codificante/genética , Retinoblastoma/genética , Antineoplásicos/farmacologia , Carboplatina/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cisplatino/farmacologia , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Etoposídeo/farmacologia , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Retinoblastoma/tratamento farmacológico , Retinoblastoma/patologia , Vincristina/farmacologia
2.
Nat Commun ; 10(1): 4846, 2019 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-31649282

RESUMO

DNA topoisomerases are required to resolve DNA topological stress. Despite this essential role, abortive topoisomerase activity generates aberrant protein-linked DNA breaks, jeopardising genome stability. Here, to understand the genomic distribution and mechanisms underpinning topoisomerase-induced DNA breaks, we map Top2 DNA cleavage with strand-specific nucleotide resolution across the S. cerevisiae and human genomes-and use the meiotic Spo11 protein to validate the broad applicability of this method to explore the role of diverse topoisomerase family members. Our data characterises Mre11-dependent repair in yeast and defines two strikingly different fractions of Top2 activity in humans: tightly localised CTCF-proximal, and broadly distributed transcription-proximal, the latter correlated with gene length and expression. Moreover, single nucleotide accuracy reveals the influence primary DNA sequence has upon Top2 cleavage-distinguishing sites likely to form canonical DNA double-strand breaks (DSBs) from those predisposed to form strand-biased DNA single-strand breaks (SSBs) induced by etoposide (VP16) in vivo.


Assuntos
Reparo do DNA , DNA Topoisomerases Tipo II/metabolismo , DNA/metabolismo , Endodesoxirribonucleases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Antineoplásicos Fitogênicos/farmacologia , Sequência de Bases , Fator de Ligação a CCCTC/genética , DNA/efeitos dos fármacos , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Quebras de DNA de Cadeia Simples/efeitos dos fármacos , Etoposídeo/farmacologia , Humanos , Mapeamento de Nucleotídeos
3.
Food Chem Toxicol ; 133: 110777, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31472227

RESUMO

Glucuronide Oleanane-type Triterpenoid Carboxylic Acid 3,28-Bidesmosides (GOTCAB) are accumulated in Gypsophila L. roots. In the study we aimed at investigating the possible synergistic effects of Gypsophila trichotoma GOTCABs and cytostatic etoposide towards the Hodgkin lymphoma cell line HD-MY-Z. The combination effects with etoposide were evaluated using the symbolic mathematical software MAPLE. Liquid chromatography-mass spectrometry allowed the identification or tentative assignment of 28 core GOTCAB structures together with 6 monodesmosides in the root extract. Tested gypsogenin-based saponins possessed C-28 ester-bonded chain substituted with acetyl, cis/trans methoxycinnamoyl and both acetyl and sulfate groups. No cytotoxic effect was observed up to 20 µg/mL on normal mice fibroblasts (CCL-1 cell line) and lymphoma cells. Etoposide alone exerted IC50 93 µg/mL. In the presence of acetylated saponins (20 µg/mL), a strong synergism (Fa = 0.8, CI = 0.1) was observed with IC50 11 µg/mL. The combination induced apoptosis witnessed by caspase activation, elevated levels of cytosolic mono- and oligonucleosomes, and nuclear fragmentation together with discernible increase in ROS generation. The results emphasize the arabinose in the C-3 chain and acetylation pattern of the C-28 chain of the saponins as important structural features for cytotoxicity enhancing activity. Triterpenoid saponins are a valuable tool to improve the efficacy of cytostatics.


Assuntos
Antineoplásicos/farmacologia , Caryophyllaceae/química , Etoposídeo/farmacologia , Saponinas/farmacologia , Triterpenos/farmacologia , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sinergismo Farmacológico , Humanos , Estrutura Molecular , Raízes de Plantas/química , Espécies Reativas de Oxigênio/metabolismo , Saponinas/química , Triterpenos/química
4.
Mol Pharmacol ; 96(4): 475-484, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31399497

RESUMO

Topoisomerase II (TOP2) poisons are effective cytotoxic anticancer agents that stabilize the normally transient TOP2-DNA covalent complexes formed during the enzyme reaction cycle. These drugs include etoposide, mitoxantrone, and the anthracyclines doxorubicin and epirubicin. Anthracyclines also exert cell-killing activity via TOP2-independent mechanisms, including DNA adduct formation, redox activity, and lipid peroxidation. Here, we show that anthracyclines and another intercalating TOP2 poison, mitoxantrone, stabilize TOP2-DNA covalent complexes less efficiently than etoposide, and at higher concentrations they suppress the formation of TOP2-DNA covalent complexes, thus behaving as TOP2 poisons at low concentration and inhibitors at high concentration. We used induced pluripotent stem cell (iPSC)-derived human cardiomyocytes as a model to study anthracycline-induced damage in cardiac cells. Using immunofluorescence, our study is the first to demonstrate the presence of topoisomerase IIß (TOP2B) as the only TOP2 isoform in iPSC-derived cardiomyocytes. In these cells, etoposide robustly induced TOP2B covalent complexes, but we could not detect doxorubicin-induced TOP2-DNA complexes, and doxorubicin suppressed etoposide-induced TOP2-DNA complexes. In vitro, etoposide-stabilized DNA cleavage was attenuated by doxorubicin, epirubicin, or mitoxantrone. Clinical use of anthracyclines is associated with cardiotoxicity. The observations in this study have potentially important clinical consequences regarding the effectiveness of anticancer treatment regimens when TOP2-targeting drugs are used in combination. These observations suggest that inhibition of TOP2B activity, rather than DNA damage resulting from TOP2 poisoning, may play a role in doxorubicin cardiotoxicity. SIGNIFICANCE STATEMENT: We show that anthracyclines and mitoxantrone act as topoisomerase II (TOP2) poisons at low concentration but attenuate TOP2 activity at higher concentration, both in cells and in in vitro cleavage experiments. Inhibition of type II topoisomerases suppresses the action of other drugs that poison TOP2. Thus, combinations containing anthracyclines or mitoxantrone and etoposide may reduce the activity of etoposide as a TOP2 poison and thus reduce the efficacy of drug combinations.


Assuntos
Antraciclinas/farmacologia , Adutos de DNA/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Etoposídeo/farmacologia , Mitoxantrona/farmacologia , Cardiotoxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Adutos de DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Doxorrubicina/efeitos adversos , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células K562 , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Inibidores da Topoisomerase II/farmacologia
5.
Artif Cells Nanomed Biotechnol ; 47(1): 3222-3230, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31373225

RESUMO

Introduction and objective: Lung cancer is the most common one in terms of outbreak and mortality. Since most modern treatments have many side effects, finding an effective and alternative therapy seems necessary. The present study aimed to determine the effect of PEGylated liposomal etoposide nanoparticles on the lung cancer (A-549 and Calu6 cell lines). Materials and methods: The PEGylated liposomal etoposide nanoparticles were prepared by reverse-phase evaporation method. The particle size and zeta potential of the nanoparticles were measured by Zetasizer. The nanoparticle cytotoxicity was examined by MTT method. The vesicular drug release pattern was examined by dialysis method. The amount of loaded drug and the encapsulation efficiency (EE) was also measured and calculated. Apoptosis test was performed using flow cytometry with Annexin V kit. Results: The mean particle size, size distribution, and zeta potential of PEGylated liposomal etoposide nanoparticles were 122.5 ± 4.8 nm, 0.252 ± 0.12 and -13.7 ± 0.51 mv, respectively. The etoposide release in prepared formulations was detected to be about 15.64% after 50 hr. The cytotoxic effect of etoposide nanoparticles on lung cancer A-549 and Calu6 cell lines showed more anti-tumour activity compared to the free drug used. Conclusion: The results showed that the PEGylated liposomal nanoparticles were used as a suitable nanocarrier for etoposide injection. It was also found that the drug effect on the nanodrug formulations was higher than that of the free drug.


Assuntos
Etoposídeo/química , Etoposídeo/farmacologia , Lipossomos/química , Neoplasias Pulmonares/patologia , Nanopartículas/química , Polietilenoglicóis/química , Células A549 , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Liberação Controlada de Fármacos , Humanos , Tamanho da Partícula
6.
J Vet Med Sci ; 81(8): 1182-1190, 2019 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-31308291

RESUMO

Canine osteosarcoma (OSA) is an aggressive and highly malignant primary bone tumor. Its poor survival outcome remains problematic despite recent advances in anti-cancer therapy, therefore highlighting the need for alternative treatment options or drug repositioning. The aim of this study was to determine if YM155, a small-molecule survivin inhibitor, potentiates the chemotherapeutic efficacy of etoposide against canine OSA in vitro and in vivo. In cell culture, YM155 enhanced the cytotoxic effect of etoposide against canine OSA cell lines; however, the molecular mechanism behind this effect was heterogeneous, as only one cell line had an elevated apoptotic level. In addition, this effect was not associated with survivin suppression in two of the cell lines. These results suggest that the molecular target of YM155 is not restricted to survivin alone. When tested on a murine xenograft model, the average tumor volume of the combination treatment group (YM155, 5 mg/kg, intraperitoneally, 5 consecutive days/week; and etoposide, 20 mg/kg, intraperitoneally, every 5 days) was 66% smaller than the control group, although this difference was not statistically significant (P=0.17). Further studies to improve the treatment protocol are necessary to confirm the findings of this study.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/veterinária , Doenças do Cão/tratamento farmacológico , Etoposídeo/farmacologia , Imidazóis/farmacologia , Naftoquinonas/farmacologia , Osteossarcoma/tratamento farmacológico , Osteossarcoma/veterinária , Animais , Apoptose/efeitos dos fármacos , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/patologia , Proliferação de Células/efeitos dos fármacos , Doenças do Cão/metabolismo , Doenças do Cão/patologia , Cães , Sinergismo Farmacológico , Humanos , Camundongos , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Survivina/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Med Sci Monit ; 25: 5630-5639, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31356586

RESUMO

BACKGROUND The hemoglobin, albumin, lymphocyte, and platelet (HALP) score is a prognostic factor in patients who have some types of malignant tumors. The aim of this study was to investigate the prognostic significance of the HALP score in patients with small cell lung cancer (SCLC) before first-line treatment with etoposide. MATERIAL AND METHODS A retrospective study included 178 patients with SCLC who received first-line chemotherapy with etoposide between September 2015 and May 2019. The baseline clinical characteristics and blood parameters were recorded. Univariate and multivariate analysis and Kaplan-Meier plots were used to identify the factors associated with progression-free survival (PFS). RESULTS The optimal cut-off values of the HALP score was determined by X-tile software to be 25.8. Univariate and multivariate analysis showed that in 178 patients, the HALP score, body mass index (BMI), and serum albumin levels had no prognostic significance. In the patient age group <65 years, a BMI ≥24 kg/m² was an independent prognostic factor (HR, 1.943; 95% CI, 1.251-3.018) (P=0.003). In the patient age group ≥65 years, a HALP score >25.8 was an independent positive prognostic factor for outcome following first-line treatment with etoposide (HR, 0.483; 95% CI, 0.270-0.865) (P=0.014). CONCLUSIONS In patients <65 years with SCLC who underwent first-line treatment with etoposide, a BMI ≥24 kg/m² an independent prognostic factor, and in patients ≥65 years, a HALP score >25.8 was an independent predictor of improved outcome, associated with increased PFS.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma de Pequenas Células do Pulmão/metabolismo , Adulto , Idoso , Biomarcadores Tumorais/sangue , Plaquetas/metabolismo , Índice de Massa Corporal , Etoposídeo/farmacologia , Etoposídeo/uso terapêutico , Feminino , Hemoglobinas/metabolismo , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/patologia , Contagem de Linfócitos , Linfócitos/metabolismo , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Intervalo Livre de Progressão , Estudos Retrospectivos , Albumina Sérica Humana/metabolismo , Carcinoma de Pequenas Células do Pulmão/fisiopatologia , Resultado do Tratamento
8.
PLoS One ; 14(7): e0219782, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31329620

RESUMO

Apoptotic protease-activating factor 1 (Apaf-1) is a component of apoptosome, which regulates caspase-9 activity. In addition to apoptosis, Apaf-1 plays critical roles in the intra-S-phase checkpoint; therefore, impaired expression of Apaf-1 has been demonstrated in chemotherapy-resistant malignant melanoma and nuclear translocation of Apaf-1 has represented a favorable prognosis of patients with non-small cell lung cancer. In contrast, increased levels of Apaf-1 protein are observed in the brain in Huntington's disease. The regulation of Apaf-1 protein is not yet fully understood. In this study, we show that etoposide triggers the interaction of Apaf-1 with Cullin-4B, resulting in enhanced Apaf-1 ubiquitination. Ubiquitinated Apaf-1, which was degraded in healthy cells, binds p62 and forms aggregates in the cytosol. This complex of ubiquitinated Apaf-1 and p62 induces caspase-9 activation following MG132 treatment of HEK293T cells that stably express bcl-xl. These results show that ubiquitinated Apaf-1 may activate caspase-9 under conditions of proteasome impairment.


Assuntos
Fator Apoptótico 1 Ativador de Proteases/metabolismo , Caspase 9/metabolismo , Proteínas Culina/metabolismo , Ubiquitinação , Ativação Enzimática/efeitos dos fármacos , Etoposídeo/farmacologia , Células HEK293 , Humanos , Leupeptinas/farmacologia , Ligação Proteica/efeitos dos fármacos , Ubiquitinação/efeitos dos fármacos , Proteína bcl-X/metabolismo
9.
Mater Sci Eng C Mater Biol Appl ; 102: 96-105, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31147064

RESUMO

In this article, we have reported the inclusion complex behaviors and their pharmaceutical application of anticancer drug property of Etoposide with ß-cyclodextrin. The inclusion complex is used to improve the poor aqueous solubility of the anticancer drug Etoposide. The aqueous solubility and in-vitro dissolution studies support to the anticancer drug Etoposide with ß-cyclodextrin complex is significantly improves the aqueous solubility. Etoposide:ß-cyclodextrin solid-state complexes were prepared by Physical mixture, kneading and solvent evaporation methods, and were characterized by FT-IR, 1HNMR, XRD, DSC and SEM techniques. In addition, the in-vitro antimicrobial and antibiofilm study of Etoposide drug is a sensible microorganism was significantly increased by an inclusion complexation process. The antibiofilm of anticancer drug Etoposide with ß-cyclodextrin studies have been analyzed by confocal laser scanning microscopy.


Assuntos
Antineoplásicos/farmacologia , Bactérias/efeitos dos fármacos , Etoposídeo/farmacologia , beta-Ciclodextrinas/farmacologia , Bacillus licheniformis/efeitos dos fármacos , Bactérias/ultraestrutura , Biofilmes/efeitos dos fármacos , Varredura Diferencial de Calorimetria , Testes de Sensibilidade Microbiana , Espectroscopia de Prótons por Ressonância Magnética , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Vibrio parahaemolyticus/efeitos dos fármacos , Difração de Raios X
10.
Nucleic Acids Res ; 47(15): e89, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31165870

RESUMO

Optical DNA mapping (ODM) allows visualization of long-range sequence information along single DNA molecules. The data can for example be used for detecting long range structural variations, for aiding DNA sequence assembly of complex genomes and for mapping epigenetic marks and DNA damage across the genome. ODM traditionally utilizes sequence specific marks based on nicking enzymes, combined with a DNA stain, YOYO-1, for detection of the DNA contour. Here we use a competitive binding approach, based on YOYO-1 and netropsin, which highlights the contour of the DNA molecules, while simultaneously creating a continuous sequence specific pattern, based on the AT/GC variation along the detected molecule. We demonstrate and validate competitive-binding-based ODM using bacterial artificial chromosomes (BACs) derived from the human genome and then turn to DNA extracted from white blood cells. We generalize our findings with in-silico simulations that show that we can map a vast majority of the human genome. Finally, we demonstrate the possibility of combining competitive binding with enzymatic labeling by mapping DNA damage sites induced by the cytotoxic drug etoposide to the human genome. Overall, we demonstrate that competitive-binding-based ODM has the potential to be used both as a standalone assay for studies of the human genome, as well as in combination with enzymatic approaches, some of which are already commercialized.


Assuntos
Benzoxazóis/química , Mapeamento Cromossômico/métodos , DNA/química , Genoma Humano , Netropsina/química , Compostos de Quinolínio/química , Análise de Sequência de DNA/métodos , Antineoplásicos Fitogênicos/farmacologia , Sítios de Ligação , Ligação Competitiva , Cromossomos Artificiais Bacterianos/química , DNA/genética , Etoposídeo/farmacologia , Corantes Fluorescentes/química , Humanos , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/metabolismo , Imagem Individual de Molécula/métodos
11.
Int J Oncol ; 54(6): 2117-2126, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31081052

RESUMO

Transforming growth factor-ß1 (TGF-ß1) is a multifunctional cytokine that functions as a growth suppressor in normal epithelial cells and early stage tumors, but acts as a tumor promoter during malignant progression. However, the molecular basis underlying the conversion of TGF­ß1 function remains largely undefined. X­linked inhibitor of apoptosis­associated factor 1 (XAF1) is a pro­apoptotic tumor suppressor that frequently displays epigenetic inactivation in various types of human malignancies, including colorectal cancer. The present study explored whether the anti­apoptotic effect of TGF­ß1 is linked to its regulatory effect on XAF1 induction in human colon cancer cells under stressful conditions. The results revealed that TGF­ß1 treatment protected tumor cells from various apoptotic stresses, including 5­fluorouracil, etoposide and γ­irradiation. XAF1 expression was activated at the transcriptional level by these apoptotic stresses and TGF­ß1 blocked the stress­mediated activation of the XAF1 promoter. The study also demonstrated that mitogen­activated protein kinase kinase inhibition or extracellular signal­activated kinase (Erk)1/2 depletion induced XAF1 induction, while the activation of K­Ras (G12C) led to its reduction. In addition, TGF­ß1 blocked the stress­mediated XAF1 promoter activation and induction of apoptosis. This effect was abrogated if Erk1/2 was depleted, indicating that TGF­ß1 represses XAF1 transcription through Erk activation, thereby protecting tumor cells from apoptotic stresses. These findings point to a novel molecular mechanism underlying the tumor­promoting function of TGF­ß1, which may be utilized in the development of a novel therapeutic strategy for the treatment of colorectal cancer.


Assuntos
Neoplasias do Colo/metabolismo , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Neoplasias/genética , Fator de Crescimento Transformador beta1/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular , Neoplasias do Colo/genética , Progressão da Doença , Etoposídeo/farmacologia , Fluoruracila/farmacologia , Raios gama/efeitos adversos , Regulação Neoplásica da Expressão Gênica , Células HT29 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Sistema de Sinalização das MAP Quinases , Proteínas de Neoplasias/metabolismo , Regiões Promotoras Genéticas , Proteínas ras/metabolismo
12.
Nat Genet ; 51(6): 1011-1023, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31110352

RESUMO

It is not clear how spontaneous DNA double-strand breaks (DSBs) form and are processed in normal cells, and whether they predispose to cancer-associated translocations. We show that DSBs in normal mammary cells form upon release of paused RNA polymerase II (Pol II) at promoters, 5' splice sites and active enhancers, and are processed by end-joining in the absence of a canonical DNA-damage response. Logistic and causal-association models showed that Pol II pausing at long genes is the main predictor and determinant of DSBs. Damaged introns with paused Pol II-pS5, TOP2B and XRCC4 are enriched in translocation breakpoints, and map at topologically associating domain boundary-flanking regions showing high interaction frequencies with distal loci. Thus, in unperturbed growth conditions, release of paused Pol II at specific loci and chromatin territories favors DSB formation, leading to chromosomal translocations.


Assuntos
Quebras de DNA de Cadeia Dupla , Loci Gênicos , Neoplasias/genética , Neoplasias/metabolismo , RNA Polimerase II/metabolismo , Animais , Linhagem Celular Tumoral , Células Cultivadas , Reparo do DNA , Elementos Facilitadores Genéticos , Etoposídeo/farmacologia , Citometria de Fluxo , Imunofluorescência , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genômica/métodos , Íntrons , Neoplasias/patologia , Regiões Promotoras Genéticas , Sítios de Splice de RNA , Inibidores da Topoisomerase/farmacologia , Sítio de Iniciação de Transcrição
13.
J BUON ; 24(2): 449-455, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31127990

RESUMO

PURPOSE: To study the effect of transforming growth factor (TGF)-ß1 on apoptosis of colon cancer cells via the ERK signaling pathway. METHODS: Human chemosensitive colon cancer cell line HT- 29 was used in this study. VEGF mRNA and protein level were detected using PCR and western blot. Enzyme-linked immunosorbent assay (ELISA) was used for prostaglandin (PG) detection. Cell proliferation was determined via MTT assay. RESULTS: TGF-ß1 had a significant effect on blocking the cancer cell growth (p<0.05). TGF-ß1 significantly reduced the VEGF mRNA level (p<0.05) and eliminated the COX-2 expression in a dose-dependent manner, while p53 expression was increased (p<0.05). TGF-ß1-induced inhibitory effect on COX-2 was significantly eliminated by the ERK inhibitor Compound C (p<0.05). The basal PGE2 production was eliminated in cells treated with TGF-ß1 (p<0.05). N-acetylcysteine (NAC) treatment almost completely eliminated the reactive oxygen species (ROS) produced by TGF-ß1 and ERK activation. Compared with administration of 5-FU or etoposide alone, TGF-Β1 combined with 5-FU or etoposide significantly administration the viability of colon cancer HT-29 cells. CONCLUSION: ERK is a newly-identified cancer target molecule, which can significantly control COX-2 in colon cancer cells treated with TGF-ß1.


Assuntos
Apoptose/genética , Neoplasias do Colo/genética , Ciclo-Oxigenase 2/genética , Proteína Quinase 1 Ativada por Mitógeno/genética , Fator de Crescimento Transformador beta1/genética , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Colo/metabolismo , Colo/patologia , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Etoposídeo/farmacologia , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HT29 , Humanos , Sistema de Sinalização das MAP Quinases/genética , Espécies Reativas de Oxigênio/metabolismo
14.
Mol Biol Rep ; 46(4): 3625-3636, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31020489

RESUMO

Topoisomerase II (Topo2) inhibitors in combination with cisplatin represent a common treatment modality used for glioma patients. The main mechanism of their action involves induction of DNA double-strand breaks (DSBs). DSBs are repaired via the homology-dependent DNA repair (HRR) and non-homologous end-joining (NHEJ). Inhibition of the NHEJ or HRR pathway sensitizes cancer cells to the treatment. In this work, we investigated the effect of three Topo2 inhibitors-etoposide, NK314, or HU-331 in combination with cisplatin in the U-87 human glioblastoma cell line. Etoposide as well as NK314 inhibited Topo2 activity by stabilizing Topo2-DNA cleavable complexes whereas HU-331 inhibited the ATPase activity of Topo2 using a noncompetitive mechanism. To increase the effectiveness of the treatment, we combined cisplatin and Topo2 inhibitor treatment with DSB repair inhibitors (DRIs). The cells were sensitized with NHEJ inhibitor, NU7441, or the novel HRR inhibitor, YU238259, prior to drug treatment. All of the investigated Topo2 inhibitors in combination with cisplatin efficiently killed the U-87 cells. The most cytotoxic effect was observed for the cisplatin + HU331 treatment scheme and this effect was significantly increased when a DRI pretreatment was used; however, we did not observed DSBs. Therefore, the molecular mechanism of cytotoxicity caused by the cisplatin + HU331 treatment scheme is yet to be evaluated. We observed a concentration-dependent change in DSB levels and accumulation at the G2/M checkpoint and S-phase in glioma cells incubated with NK314/cisplatin and etoposide/cisplatin. In conclusion, in combination with cisplatin, HU331 is the most potent Topo2 inhibitor of human glioblastoma cells.


Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Cisplatino/farmacologia , Glioblastoma/tratamento farmacológico , Fenantrenos/farmacologia , Inibidores da Topoisomerase II/farmacologia , Apoptose/efeitos dos fármacos , Benzamidas/farmacologia , Neoplasias Encefálicas/metabolismo , Canabidiol/análogos & derivados , Canabidiol/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Cromonas/farmacologia , Quebras de DNA de Cadeia Dupla , Reparo do DNA/efeitos dos fármacos , Etoposídeo/farmacologia , Glioblastoma/metabolismo , Humanos , Morfolinas/farmacologia , Sulfonamidas/farmacologia , Inibidores da Topoisomerase II/metabolismo
15.
BMC Cancer ; 19(1): 300, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30943920

RESUMO

BACKGROUND: Solid tumours are less oxygenated than normal tissues. This is called tumour hypoxia and leads to resistance to radiotherapy and chemotherapy. The molecular mechanisms underlying such resistance have been investigated in a range of tumour types, including the adult brain tumours glioblastoma, yet little is known for paediatric brain tumours. Medulloblastoma (MB) is the most common malignant brain tumour in children. We aimed to elucidate the impact of hypoxia on the sensitivity of MB cells to chemo- and radiotherapy. METHODS: We used two MB cell line (D283-MED and MEB-Med8A) and a widely used glioblastoma cell line (U87MG) for comparison. We applied a range of molecular and cellular techniques to measure cell survival, cell cycle progression, protein expression and DNA damage combined with a transcriptomic micro-array approach in D283-MED cells, for global gene expression analysis in acute and chronic hypoxic conditions. RESULTS: In D283-MED and U87MG, chronic hypoxia (5 days), but not acute hypoxia (24 h) induced resistance to chemotherapy and X-ray irradiation. This acquired resistance upon chronic hypoxia was present but less pronounced in MEB-Med8A cells. Using transcriptomic analysis in D283-MED cells, we found a large transcriptional remodelling upon long term hypoxia, in particular the expression of a number of genes involved in detection and repair of double strand breaks (DSB) was altered. The levels of Nibrin (NBN) and MRE11, members of the MRN complex (MRE11/Rad50/NBN) responsible for DSB recognition, were significantly down-regulated. This was associated with a reduction of Ataxia Telangiectasia Mutated (ATM) activation by etoposide, indicating a profound dampening of the DNA damage signalling in hypoxic conditions. As a consequence, p53 activation by etoposide was reduced, and cell survival enhanced. Whilst U87MG shared the same dampened p53 activity, upon chemotherapeutic drug treatment in chronic hypoxic conditions, these cells used a different mechanism, independent of the DNA damage pathway. CONCLUSION: Together our results demonstrate a new mechanism explaining hypoxia-induced resistance involving the alteration of the response to DSB in D283-MED cells, but also highlight the cell type to cell type diversity and the necessity to take into account the differing tumour genetic make-up when considering re-sensitisation therapeutic protocols.


Assuntos
Proteínas de Ciclo Celular/genética , Neoplasias Cerebelares/genética , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos , Perfilação da Expressão Gênica/métodos , Meduloblastoma/genética , Proteínas Nucleares/genética , Ciclo Celular , Hipóxia Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Neoplasias Cerebelares/tratamento farmacológico , Etoposídeo/farmacologia , Regulação Neoplásica da Expressão Gênica , Humanos , Meduloblastoma/tratamento farmacológico , Análise de Sequência com Séries de Oligonucleotídeos , Tolerância a Radiação
16.
Biomed Pharmacother ; 112: 108714, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30970518

RESUMO

Changes in the expression and subcellular localization of high mobility group box 1 (HMGB1), a damage-associated molecular pattern (DAMP) molecule, have been implicated in tumorigenesis and tumor cell death in response to cancer therapy. Specifically, HMGB1 release has been shown to occur with a specific form of induced cell death known as necroptosis. In the present study, we examined the role of HMGB1 in the necroptosis of acute myeloid leukemia (AML) cells. In two AML cell lines and primary AML cells from two patients, etoposide induced necroptosis via cIAP1/2 degradation when caspase activity was inhibited by Z-VAD-fmk, but treatment with extracellular HMGB1 prevented this necroptosis. Interestingly, HMGB1 did not prevent the degradation of cIAP1/2, but rather activated the nuclear factor kappa B pathway. The results of the present study provide evidence that extracellular HMGB1 is not only an important DAMP molecule released by cells upon necrosis, but also a regulatory factor that prevents necroptosis in AML cells.


Assuntos
Alarminas/metabolismo , Apoptose , Espaço Extracelular/metabolismo , Proteína HMGB1/metabolismo , Leucemia Mieloide Aguda/patologia , Necrose , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Etoposídeo/farmacologia , Células HL-60 , Humanos , Leucemia Mieloide Aguda/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais
17.
ACS Appl Mater Interfaces ; 11(20): 18111-18122, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31006230

RESUMO

The study of multifunctional polymer micelles combined with chemotherapy due to reduced systemic toxicity and enhanced efficacy has attracted intensive attention. Herein, a multifunctional core-cross-linked hybrid micelle system based on mPEG- b-PGu(BA-TPE) and OCT-PEG- b-PGu(DA-TPE) with pH- and redox-triggered drug release and aggregation-induced emission (AIE) active imaging has been developed for active targeting of neuroendocrine neoplasms (NENs), especially neuroendocrine carcinomas (NECs) with poor prognosis. These micelles showed excellent biocompatibility and stability. After the formation of borate ester bonds, core-cross-linked micelles (CCLMs) showed enhanced emission properties. In addition, etoposide (ETO), one of the most important anticancer drugs of NECs, was loaded into the hydrophobic core of micelles by self-assembly with an average diameter of 274.6 nm and spherical morphology. Octreotide (OCT) conjugated onto the micelles enhanced cellular uptake by receptor-mediated endocytosis. ETO-loaded micelles demonstrated the dual-responsive triggered intracellular drug release and great tumor suppression ability in vitro. Compared with free ETO, ETO-loaded CCLMs exhibited a considerable antitumor effect and significantly reduced side effects. Considering the active tumor targeting, dual-responsive drug release and the AIE effect, the polymer micelle system will be a potential candidate for diagnosis and oncotherapy of NENs.


Assuntos
Antineoplásicos , Etoposídeo , Micelas , Neoplasias/tratamento farmacológico , Octreotida , Células A549 , Animais , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Etoposídeo/química , Etoposídeo/farmacocinética , Etoposídeo/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias/metabolismo , Neoplasias/patologia , Octreotida/química , Octreotida/farmacocinética , Octreotida/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
18.
J Microbiol Biotechnol ; 29(4): 571-576, 2019 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-30955254

RESUMO

Microenvironmental stress, which is naturally observed in solid tumors, has been implicated in anticancer drug resistance. This tumor-specific stress causes the degradation of topoisomerase IIα, rendering cells resistant to topoisomerase IIα-targeted anticancer agents. In addition, microenvironmental stress can induce the overexpression of 78kDa glucose regulated protein (GRP78), which can subsequently block the activation of apoptosis induced by treatment with anticancer agents. Therefore, inhibition of topoisomerase IIα degradation and reduction in GRP78 expression may be effective strategies for inhibiting anticancer drug resistance. In this study, we investigated the active compound arctigenin, which inhibited microenvironmental stress-induced etoposide resistance in HT-29 cells. Arctigenin was also highly toxic to etoposide-resistant HT-29 cells, with an IC50 value of 10 µM for colony formation. We further showed that arctigenin inhibited the degradation of topoisomerase IIα and reduced the expression of GRP78. Thus, these results suggest that arctigenin is a novel therapeutic agent that inhibits resistance to etoposide associated with microenvironmental stress conditions.


Assuntos
Antineoplásicos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Etoposídeo/farmacologia , Furanos/antagonistas & inibidores , Células HT29/efeitos dos fármacos , Lignanas/antagonistas & inibidores , Estresse Fisiológico , Microambiente Tumoral/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaio de Unidades Formadoras de Colônias , DNA Topoisomerases Tipo II , Furanos/química , Células HT29/citologia , Proteínas de Choque Térmico/metabolismo , Humanos , Lignanas/química
19.
Oncol Res ; 27(6): 703-712, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-30841958

RESUMO

Glioma is a commonly diagnosed brain tumor that shows high mortality rate. Despite the great advancement of cancer therapy in recent years, chemotherapy is still an important approach for treatment of glioma. However, long-term chemotherapy usually causes serious side effects or complications. It is desirable to take strategies to enhance the efficacy of current chemotherapy. In the present study, we observed obvious upregulation of miR-374a in glioma cells. More importantly, we found that knockdown of miR-374a was able to enhance the etoposide-induced cytotoxicity against glioma cells. Mechanically, we demonstrated that FOXO1 was the target of miR-374a in glioma. Treatment with miR-374a inhibitor induced overexpression of FOXO1, and thus promoted the expression of Bim and Noxa. Since Bim and Noxa act as key proapoptotic proteins in mitochondrial apoptosis, miR-374a inhibitor was able to enhance the etoposide-induced apoptosis pathway in glioma.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Etoposídeo/farmacologia , Proteína Forkhead Box O1/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioma/genética , MicroRNAs/genética , Regiões 3' não Traduzidas , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Interferência de RNA
20.
Int J Surg Pathol ; 27(5): 568-573, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30907195

RESUMO

Adult neuroblastoma is an extremely infrequent neoplasm, usually occurring in the adrenal medulla or in the paraspinal sympathetic ganglia, as its childhood counterpart. We report a very unusual case of a Schwannian stroma-poor adult neuroblastoma of inguinal location, showing aberrant expression of germ cell markers: SALL4 and OCT4. This aberrant marker expression, the unusual positivity for NKX2.2 and the very scattered (instead of diffuse strong) PHOX2B expression, complicated the initial diagnosis. In this case, the posttreatment histological evaluation revealed the neuroblastic nature of the lesion. Neuroblastoma maturation after treatment is an unusual finding in adults, and in this case, added an important clue for the final diagnosis. Germs cells markers expression in neuroblastoma is an interesting feature to explore and may define a subset of neuroblastomas with a different biological nature.


Assuntos
Neoplasias Abdominais/diagnóstico , Biomarcadores Tumorais/metabolismo , Células Germinativas/patologia , Canal Inguinal/patologia , Neuroblastoma/diagnóstico , Neoplasias Abdominais/patologia , Neoplasias Abdominais/terapia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimiorradioterapia/métodos , Ciclofosfamida/farmacologia , Ciclofosfamida/uso terapêutico , Dactinomicina/farmacologia , Dactinomicina/uso terapêutico , Diagnóstico Diferencial , Etoposídeo/farmacologia , Etoposídeo/uso terapêutico , Células Germinativas/efeitos dos fármacos , Humanos , Ifosfamida/farmacologia , Ifosfamida/uso terapêutico , Canal Inguinal/diagnóstico por imagem , Masculino , Neuroblastoma/patologia , Neuroblastoma/terapia , Fator 3 de Transcrição de Octâmero/metabolismo , Fatores de Transcrição/metabolismo , Vincristina/farmacologia , Vincristina/uso terapêutico
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