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1.
Adv Exp Med Biol ; 1268: 227-253, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32918222

RESUMO

Exposure of skin cells to UV radiation results in DNA damage, which if inadequately repaired, may cause mutations. UV-induced DNA damage and reactive oxygen and nitrogen species also cause local and systemic suppression of the adaptive immune system. Together, these changes underpin the development of skin tumours. The hormone derived from vitamin D, calcitriol (1,25-dihydroxyvitamin D3) and other related compounds, working via the vitamin D receptor and at least in part through endoplasmic reticulum protein 57 (ERp57), reduce cyclobutane pyrimidine dimers and oxidative DNA damage in keratinocytes and other skin cell types after UV. Calcitriol and related compounds enhance DNA repair in keratinocytes, in part through decreased reactive oxygen species, increased p53 expression and/or activation, increased repair proteins and increased energy availability in the cell when calcitriol is present after UV exposure. There is mitochondrial damage in keratinocytes after UV. In the presence of calcitriol, but not vehicle, glycolysis is increased after UV, along with increased energy-conserving autophagy and changes consistent with enhanced mitophagy. Reduced DNA damage and reduced ROS/RNS should help reduce UV-induced immune suppression. Reduced UV immune suppression is observed after topical treatment with calcitriol and related compounds in hairless mice. These protective effects of calcitriol and related compounds presumably contribute to the observed reduction in skin tumour formation in mice after chronic exposure to UV followed by topical post-irradiation treatment with calcitriol and some, though not all, related compounds.


Assuntos
Calcitriol/farmacologia , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/efeitos da radiação , Dano ao DNA/efeitos dos fármacos , Raios Ultravioleta/efeitos adversos , Vitamina D/farmacologia , Animais , Calcitriol/química , Calcitriol/metabolismo , Humanos , Vitamina D/química , Vitamina D/metabolismo , Vitaminas/química , Vitaminas/metabolismo , Vitaminas/farmacologia
2.
Anticancer Res ; 40(10): 5399-5404, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988859

RESUMO

BACKGROUND/AIM: The aim of the present study was to investigate whether idarubicin (IDR) induces oxidative DNA damage in the presence of copper (II). MATERIALS AND METHODS: DNA damage was evaluated by pBR322 plasmid DNA cleavage. The formation of oxidative stress markers [O2 •- and 8-hydroxy-2'-deoxyguanosine (8-OHdG)] was analysed. RESULTS: IDR induced DNA damage and O2 •- and 8-OHdG generation in the presence of copper (II). CONCLUSION: IDR induced oxidative DNA damage in the presence of copper (II). Since it has been reported that the concentration of copper in the serum of cancer patients is higher than that in healthy groups, IDR-induced oxidative DNA damage in the presence of copper (II) may play an important role in anticancer therapeutic strategies.


Assuntos
Antraciclinas/farmacologia , Idarubicina/farmacologia , Neoplasias/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Antraciclinas/química , Cobre/química , Dano ao DNA/efeitos dos fármacos , Humanos , Idarubicina/química , Neoplasias/genética , Neoplasias/patologia , Espécies Reativas de Oxigênio/química , Superóxido Dismutase/genética
3.
Mol Cell ; 79(6): 1008-1023.e4, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32871104

RESUMO

TMPRSS2-ERG gene fusion occurs in approximately 50% of cases of prostate cancer (PCa), and the fusion product is a key driver of prostate oncogenesis. However, how to leverage cellular signaling to ablate TMPRSS2-ERG oncoprotein for PCa treatment remains elusive. Here, we demonstrate that DNA damage induces proteasomal degradation of wild-type ERG and TMPRSS2-ERG oncoprotein through ERG threonine-187 and tyrosine-190 phosphorylation mediated by GSK3ß and WEE1, respectively. The dual phosphorylation triggers ERG recognition and degradation by the E3 ubiquitin ligase FBW7 in a manner independent of a canonical degron. DNA damage-induced TMPRSS2-ERG degradation was abolished by cancer-associated PTEN deletion or GSK3ß inactivation. Blockade of DNA damage-induced TMPRSS2-ERG oncoprotein degradation causes chemotherapy-resistant growth of fusion-positive PCa cells in culture and in mice. Our findings uncover a previously unrecognized TMPRSS2-ERG protein destruction mechanism and demonstrate that intact PTEN and GSK3ß signaling are essential for effective targeting of ERG protein by genotoxic therapeutics in fusion-positive PCa.


Assuntos
Proteínas de Ciclo Celular/genética , Glicogênio Sintase Quinase 3 beta/genética , Proteínas de Fusão Oncogênica/genética , PTEN Fosfo-Hidrolase/genética , Neoplasias da Próstata/genética , Proteínas Tirosina Quinases/genética , Animais , Carcinogênese/genética , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Tratamento Farmacológico , Proteína 7 com Repetições F-Box-WD/genética , Xenoenxertos , Humanos , Masculino , Camundongos , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Proteólise/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
4.
Anticancer Res ; 40(9): 5159-5170, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32878804

RESUMO

BACKGROUND/AIM: The aim of this study was to elucidate the possibility of sensitizing colon cancer cells to the chemotherapeutic drug SN38 and investigate its mechanism of action after combined treatment with electroporation (EP). MATERIALS AND METHODS: Cells were treated with SN38, EP and their combination for 24/48 h. The cell viability, actin cytoskeleton integrity, mitochondrial superoxide, hydroperoxides, total glutathione, phosphatidyl serine expression, DNA damages and expression of membrane ABC transporters were analyzed using conventional analytical tests. RESULTS: The combination of EP and SN38 affected cell viability and cytoskeleton integrity. This effect was accompanied by: (i) high production of intracellular superoxide and hydroperoxides and depletion of glutathione; (ii) increased DNA damage and apoptotic/ferroptotic cell death; (iii) changes in the expression of membrane ABC transporters - up-regulation of SLCO1B1 and retention of SN38 in the cells. CONCLUSION: The anticancer effect of the combined treatment of SN38 and EP is related to changes in the redox-homeostasis of cancer cells, leading to cell death via apoptosis and/or ferroptosis. Thus, electroporation has a potential to increase the sensitivity of cancer cells to conventional anticancer therapy with SN38.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Oxirredução , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Dano ao DNA/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Sinergismo Farmacológico , Imunofluorescência , Glutationa/metabolismo , Humanos , Modelos Biológicos , Espécies Reativas de Oxigênio/metabolismo
5.
J Environ Pathol Toxicol Oncol ; 39(2): 191-199, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32749127

RESUMO

We have proven that naringin, a phytonutrient, diminishes oxidative damage and inflammatory responses by modulating PPAR-γ expressions in ultraviolet-B radiation (UVB)-induced NIH-3T3 cells. However, the role of naringin against DNA damage, photoaging, and apoptosis in NIH-3T3 cells has yet to be studied, necessitating investigation. We show that Naringin pretreatment significantly reduces UVB-induced alkaline DNA damage and potentially modulates NER gene (XPC, TFIIH, XPE, ERCC1, and GAPDH) expression, thereby augmenting DNA repair. We determined experimentally that naringin pretreatment prevents UVB-induced nuclear fragmentation in NIH-3T3 cells, as well as altering UVB-induced apoptotic marker (Bax, BCl-2, Caspase-9, and Caspase-3) expression in them. In addition, naringin pretreatment inhibits UVB-stimulated matrix metalloproteinase (MMP-2, MMP-9 and MMP-13) expression in these 3T3 cells. Therefore, we report that naringin can effectively avert UVB-mediated DNA damage, photoaging, and apoptosis in NIH-3T3 cells.


Assuntos
Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Flavanonas/farmacologia , Raios Ultravioleta/efeitos adversos , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Apoptose/efeitos da radiação , Reparo do DNA/efeitos da radiação , Metaloproteinases da Matriz/genética , Metaloproteinases da Matriz/metabolismo , Camundongos , Células NIH 3T3 , Protetores contra Radiação/farmacologia , Envelhecimento da Pele/efeitos dos fármacos
6.
Nat Commun ; 11(1): 4083, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32796829

RESUMO

Proper chromatin function and maintenance of genomic stability depends on spatiotemporal coordination between the transcription and replication machinery. Loss of this coordination can lead to DNA damage from increased transcription-replication collision events. We report that deregulated transcription following BRD4 loss in cancer cells leads to the accumulation of RNA:DNA hybrids (R-loops) and collisions with the replication machinery causing replication stress and DNA damage. Whole genome BRD4 and γH2AX ChIP-Seq with R-loop IP qPCR reveals that BRD4 inhibition leads to accumulation of R-loops and DNA damage at a subset of known BDR4, JMJD6, and CHD4 co-regulated genes. Interference with BRD4 function causes transcriptional downregulation of the DNA damage response protein TopBP1, resulting in failure to activate the ATR-Chk1 pathway despite increased replication stress, leading to apoptotic cell death in S-phase and mitotic catastrophe. These findings demonstrate that inhibition of BRD4 induces transcription-replication conflicts, DNA damage, and cell death in oncogenic cells.


Assuntos
Proteínas de Ciclo Celular/farmacologia , Dano ao DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Estruturas R-Loop/efeitos dos fármacos , Fatores de Transcrição/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Proteínas de Transporte , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Quinase 1 do Ponto de Checagem/metabolismo , Cromatina , Proteínas de Ligação a DNA , Instabilidade Genômica , Células HeLa , Humanos , Histona Desmetilases com o Domínio Jumonji/genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Neoplasias/terapia , Proteínas Nucleares/metabolismo , Fase S , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcriptoma
7.
Chem Biol Interact ; 330: 109114, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32735800

RESUMO

Tebuconazole (TEB) is a broad-spectrum conazole fungicide that has been used in agriculture in the control of foliar and soil-borne diseases of many crops. The present study has investigated the adverse effects of subchronic exposure to TEB on the kidney of male rats. Animals were divided into four equal groups and treated with TEB at increasing doses 0.9, 9 and 27 mg/kg body weight for 28 consecutive days. The results showed that TEB induced oxidative stress in the kidney demonstrated by an increase in malondialdehyde (MDA), protein carbonyl (PC), advanced oxidation protein product (AOPP) levels and DNA damage, as compared to the controls. Furthermore, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities were increased in the renal tissue of treated rats. Moreover, significant decrease in reduced glutathione (GSH) content in TEB-treated rats was observed, while oxidized glutathione (GSSG) levels were increased, thus a marked fall in GSH/GSSG ratio was registered in the kidney. Glutathione reductase (GR) activity showed a significant increase after TEB exposure. Moreover, TEB down-regulated the expression of Bcl2 and up-regulated the expression of Bax and caspase 3, which triggered apoptosis via the Bax/Bcl2 and caspase pathway. Also, TEB administration resulted in altered biochemical indicators of renal function and varying lesions in the overall histo-architecture of renal tissues. Taken together, our findings brought into light the renal toxicity induced by TEB, which was found to be significant at low doses.


Assuntos
Apoptose/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Rim/patologia , Estresse Oxidativo/efeitos dos fármacos , Triazóis/toxicidade , Animais , Relação Dose-Resposta a Droga , Fungicidas Industriais/toxicidade , Regulação da Expressão Gênica , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Glutationa Redutase/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Masculino , Oxirredução , Ratos , Ratos Wistar
8.
Chem Biol Interact ; 330: 109227, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32818478

RESUMO

The use of 3D models in various scientific applications is becoming more popular to replace traditional monolayers models. In this work, we used a three-dimensional in-house model of epidermis using HaCaT immortalized cells to evaluate the dermal toxicity induced by Basic Blue 99 and Basic Red 51, both present in commercial hair dye formulations. Our data show that cells cultured in the 3D model respond differently to those cultured in monolayer. Basic Red 51 dye induces apoptosis an DNA breaks in both models, however, these effects is more pronounced in cells cultured in monolayer. The toxic mode of action of Basic Blue 99 seems to be the induction of cell death, without genotoxic effects, but while the necrotic pathway is observed in HaCaT monolayer cell culture, was apoptosis seen in the Equivalent Human Epidermis (EHE) model. We could also confirm that cells in EHE model, an environment that could better mimic human effects, react differently to chemical stressors than the cells cultivated in 2D.


Assuntos
Técnicas de Cultura de Células/métodos , Epiderme/efeitos dos fármacos , Tinturas para Cabelo/toxicidade , Apoptose/efeitos dos fármacos , Compostos Azo/toxicidade , Técnicas de Cultura de Células/normas , Linhagem Celular , Dano ao DNA/efeitos dos fármacos , Tinturas para Cabelo/análise , Humanos , Naftoquinonas/toxicidade , Necrose/induzido quimicamente , Compostos de Amônio Quaternário/toxicidade
9.
Chem Biol Interact ; 330: 109219, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32846153

RESUMO

The lack of tissue selectivity of anticancer drugs generates intense collateral and adverse effects of cancer patients, making the incorporation of vitamins or micronutrients into the diet of individuals to reduce side or adverse effects of antineoplastics. The study aimed to evaluate the effects of retinol palmitate (RP) on the toxicogenic damages induced by cyclophosphamide (CPA), doxorubicin (DOX) and its association with the AC protocol (CPA + DOX), in Sarcoma 180 (S-180) tumor cell line, using the micronuclei test with a block of cytokinesis (CBMN); and in non-tumor cells derived from Mus musculus using the comet assay. The results suggest that CPA, DOX and AC protocol induced significant toxicogenic damages (P < 0.05) on the S-180 cells by induction of micronuclei, cytoplasmic bridges, nuclear buds, apoptosis, and cell necrosis, proving their antitumor effects, and significant damage (P < 0.001) to the genetic material of peripheral blood cells of healthy mice, proving the genotoxic potential of these drugs. However, RP modulated the toxicogenic effects of antineoplastic tested both in the CBMN test (P < 0.05), at the concentrations of 1, 10 and 100 IU/mL; as in the comet assay (P < 0.001) at the concentration of 100 IU/kg for the index and frequency of genotoxic damage. The accumulated results suggest that RP reduced the action of antineoplastics in non-tumor cells as well as the cytotoxic, mutagenic, and cell death in neoplastic cells.


Assuntos
Antineoplásicos/toxicidade , Diterpenos/farmacologia , Vitamina A/análogos & derivados , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/toxicidade , Apoptose/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Ensaio Cometa , Ciclofosfamida/efeitos adversos , Ciclofosfamida/toxicidade , Dano ao DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Doxorrubicina/efeitos adversos , Doxorrubicina/toxicidade , Interações Medicamentosas , Humanos , Camundongos , Testes para Micronúcleos , Mutagênese/efeitos dos fármacos , Vitamina A/farmacologia
10.
Yonsei Med J ; 61(7): 587-596, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32608202

RESUMO

PURPOSE: The current study aimed to investigate the synergistic antitumor effect of combined treatment with 17-DMAG (HSP90 inhibitor) and NVP-BEZ235 (PI3K/mTOR dual inhibitor) on cisplatin-resistant human bladder cancer cells. MATERIALS AND METHODS: Human bladder cancer cells exhibiting cisplatin resistance (T24R2) were exposed to escalating doses of 17-DMAG (2.5-20 nM) with or without NVP-BEZ236 (0.5-4 µM) in combination with cisplatin. Antitumor effects were assessed by CCK-8 analysis. Based on the dose-response study, synergistic interactions between the two regimens were evaluated using clonogenic assay and combination index values. Flow cytometry and Western blot were conducted to analyze mechanisms of synergism. RESULTS: Dose- and time-dependent antitumor effects for 17-DMAG were observed in both cisplatin-sensitive (T24) and cisplatin-resistant cells (T24R2). The antitumor effect of NVP-BEZ235, however, was found to be self-limiting. The combination of 17-DMAG and NVP-BEZ235 in a 1:200 fixed ratio showed a significant antitumor effect in cisplatin-resistant bladder cancer cells over a wide dose range, and clonogenic assay showed compatible results with synergy tests. Three-dimensional analysis revealed strong synergy between the two drugs with a synergy volume of 201.84 µM/mL²%. The combination therapy resulted in G1-phase cell cycle arrest and caspase-dependent apoptosis confirmed by the Western blot. CONCLUSION: HSP90 inhibitor monotherapy and in combination with the PI3K/mTOR survival pathway inhibitor NVP-BEZ235 shows a synergistic antitumor effect in cisplatin-resistant bladder cancers, eliciting cell cycle arrest at the G1 phase and induction of caspase-dependent apoptotic pathway.


Assuntos
Antineoplásicos/uso terapêutico , Benzoquinonas/uso terapêutico , Cisplatino/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Lactamas Macrocíclicas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Serina-Treonina Quinases TOR/antagonistas & inibidores , Neoplasias da Bexiga Urinária/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica , Apoptose/efeitos dos fármacos , Benzoquinonas/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Cisplatino/farmacologia , Dano ao DNA/efeitos dos fármacos , Humanos , Imidazóis , Lactamas Macrocíclicas/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/farmacologia , Quinolinas , Serina-Treonina Quinases TOR/metabolismo
11.
Life Sci ; 257: 118074, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32673667

RESUMO

AIM: Doxorubicin (DOX) induces dose-dependent cardiotoxicity due to reactive oxygen species (ROS)-mediated oxidative stress and subsequent apoptosis of cardiomyocytes. We aimed to assess whether sodium thiosulfate (STS), which has antioxidant and antiapoptotic properties, exerts cardioprotective effects on DOX-induced cardiomyopathy. MAIN METHODS: Male C57BL/6N mice were divided into four groups, control, DOX, STS, and DOX + STS, and administered DOX (20 or 30 mg/kg) or normal saline intraperitoneally, followed by an injection of STS (2 g/kg) or normal saline 4 h later. KEY FINDINGS: The DOX group showed a poorer 6-day survival and decreased cardiac function than the DOX + STS group. The DOX group showed a marked increase in the plasma creatine kinase isoenzyme myocardial band (CK-MB) and lactate dehydrogenase (LDH) levels 10 h after DOX injection, while the DOX + STS group showed suppression of DOX-induced elevation of CK-MB and LDH levels. The DOX group showed increased 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in the heart, whereas the DOX + STS group showed increased catalase and superoxide dismutase (SOD) activities and decreased 8-OHdG levels in the heart compared with DOX group, suggesting that STS reduces DOX-induced DNA damage by improving antioxidant enzymes activities in cardiomyocytes. Additionally, the DOX + STS group showed attenuation of cleaved caspase-3 and DNA fragmentation in cardiomyocytes compared with the DOX group, suggesting that STS suppresses DOX-induced apoptosis in cardiomyocytes. SIGNIFICANCE: STS exerts cardioprotective effects against DOX-induced cardiac dysfunction partly by improving antioxidant defense and suppressing apoptosis, indicating the therapeutic potential of STS against DOX-induced cardiomyopathy.


Assuntos
Cardiotoxicidade/prevenção & controle , Dano ao DNA/efeitos dos fármacos , Doxorrubicina/toxicidade , Miócitos Cardíacos/efeitos dos fármacos , Tiossulfatos/farmacologia , Animais , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/toxicidade , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Cardiotoxicidade/etiologia , Relação Dose-Resposta a Droga , Doxorrubicina/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/patologia , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
12.
Life Sci ; 257: 118104, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32679143

RESUMO

Halofuginone (HF) from Dichroa febrifuga has shown therapeutic potential in hepatocellular, lung and colorectal cancer cell models. Evidence has also indicated that HF plays roles in caustic induced esophageal strictures and oxidative injury. However, the role of HF in esophageal squamous carcinoma (ESCC) remains unclear. In this study, we investigated HF actions and mechanisms during ESCC cell apoptosis. We observed different HF concentrations (5, 10 and 20 nM) inhibited ESCC cell survival in a time and dose-dependent manner. HF treatment markedly induced KYSE-30 and TE-1 cell apoptosis, and caspase-3 activity. Apoptosis related protein Bax expression was dramatically increased, whereas Bcl-2 levels were reduced in KYSE-30 and TE-1 cells, after HF exposure. Also, we showed that HF treatment induced DNA damage by promoting γH2AX, pATM and pATR expression. HF treatment also reduced hypoxia-inducible factor-1α (HIF-1α) and forkhead box class O 3a (FOXO3a) expression in KYSE-30 and TE-1 cells. We also showed that HF inhibited FOXO3a expression, but this was dependent on HIF-1α inhibition. Finally, FOXO3a overexpression reversed HF induced cell survival inhibition, cell apoptosis and DNA damage. FOXO3a knockdown enhanced the effects of HF on cell survival, cell apoptosis and DNA damage. In summary, HF plays inhibitory roles in ESCC cell apoptosis, via HIF-1α-FOXO3a-dependent signaling. These data support the notion that HF could act as an effective therapeutic reagent towards ESCC.


Assuntos
Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Carcinoma de Células Escamosas/tratamento farmacológico , Neoplasias Esofágicas/tratamento farmacológico , Proteína Forkhead Box O3/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Piperidinas/uso terapêutico , Quinazolinonas/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Western Blotting , Carcinoma de Células Escamosas/metabolismo , Caspase 3/metabolismo , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Neoplasias Esofágicas/metabolismo , Humanos
13.
Life Sci ; 257: 118108, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32682920

RESUMO

AIM: Preparation of pegylated gold nanorods (PEG-AuNRs) that are capable of converting near infrared (NIR) light into heat. Evaluation of cancer therapeutic efficacy and long-term toxicity of the proposed photothermal therapy in comparison with other conventional modalities. MATERIALS AND METHODS: Prepared PEG-AuNRs were characterized by measuring their absorption spectra, zeta potential, and transmission electron microscope (TEM). Cancer therapeutic efficacy was assessed by monitoring tumor growth, measuring DNA damage and superoxide dismutase (SOD) and malondialdehyde (MDA) levels in addition to examining tumor histopathology. Further analysis concerning the toxicity of all the proposed treatment modalities was also assessed by evaluating the cytotoxicity and genotoxicity in liver and kidney tissues. KEY FINDINGS: The results demonstrated that both photothermal therapy (PEG-AuNRs + NIR laser) and chemotherapy (cisplatin) have higher efficacy in diminishing Ehrlich tumor growth with significance DNA damage over the other treatment modalities. Concerning the biosafety issue, mice treated photothermally exhibited lower MDA level and higher SOD activity in liver and kidney tissues compared with other treated groups. DNA damage represented by tail moment and olive moment of kidney tissues exhibited lower values for photothermal treated group and higher values for cisplatin treated group. SIGNIFICANCE: Photothermal therapy (PEG-AuNRs + NIR laser) potentiates higher efficacy in treating Ehrlich tumor with minimum toxicity in comparison with other conventional treatment modalities.


Assuntos
Carcinoma de Ehrlich/terapia , Ouro/administração & dosagem , Nanotubos/toxicidade , Fototerapia/métodos , Animais , Carcinoma de Ehrlich/patologia , Ensaio Cometa , Dano ao DNA/efeitos dos fármacos , Feminino , Ouro/uso terapêutico , Ouro/toxicidade , Malondialdeído/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Transmissão , Nanotubos/ultraestrutura , Transplante de Neoplasias , Estresse Oxidativo , Superóxido Dismutase/metabolismo
14.
Proc Natl Acad Sci U S A ; 117(32): 19415-19424, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32719125

RESUMO

Synthetic lethality strategies for cancer therapy exploit cancer-specific genetic defects to identify targets that are uniquely essential to the survival of tumor cells. Here we show RAD27/FEN1, which encodes flap endonuclease 1 (FEN1), a structure-specific nuclease with roles in DNA replication and repair, and has the greatest number of synthetic lethal interactions with Saccharomyces cerevisiae genome instability genes, is a druggable target for an inhibitor-based approach to kill cancers with defects in homologous recombination (HR). The vulnerability of cancers with HR defects to FEN1 loss was validated by studies showing that small-molecule FEN1 inhibitors and FEN1 small interfering RNAs (siRNAs) selectively killed BRCA1- and BRCA2-defective human cell lines. Furthermore, the differential sensitivity to FEN1 inhibition was recapitulated in mice, where a small-molecule FEN1 inhibitor reduced the growth of tumors established from drug-sensitive but not drug-resistant cancer cell lines. FEN1 inhibition induced a DNA damage response in both sensitive and resistant cell lines; however, sensitive cell lines were unable to recover and replicate DNA even when the inhibitor was removed. Although FEN1 inhibition activated caspase to higher levels in sensitive cells, this apoptotic response occurred in p53-defective cells and cell killing was not blocked by a pan-caspase inhibitor. These results suggest that FEN1 inhibitors have the potential for therapeutically targeting HR-defective cancers such as those resulting from BRCA1 and BRCA2 mutations, and other genetic defects.


Assuntos
Antineoplásicos/farmacologia , Endonucleases Flap/antagonistas & inibidores , Recombinação Homóloga/efeitos dos fármacos , Neoplasias/genética , Animais , Proteína BRCA1/deficiência , Proteína BRCA1/genética , Proteína BRCA2/deficiência , Proteína BRCA2/genética , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Endonucleases Flap/genética , Instabilidade Genômica/genética , Humanos , Camundongos , Neoplasias/tratamento farmacológico , RNA Interferente Pequeno/farmacologia , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/genética , Bibliotecas de Moléculas Pequenas/farmacologia , Mutações Sintéticas Letais , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Mutat Res ; 854-855: 503199, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32660827

RESUMO

The bacterial reverse mutation test (Ames test) is the most commonly used genotoxicity test; it is a primary component of the chemical safety assessment data required by regulatory agencies worldwide. Within the current accepted in vitro genotoxicity test battery, it is considered capable of revealing DNA reactivity, and identifying substances that can produce gene mutations via different mechanisms. The previously published consolidated EURL ECVAM Genotoxicity and Carcinogenicity Database, which includes substances that elicited a positive response in the Ames test, constitutes a collection of data that serves as a reference for a number of regulatory activities in the area of genotoxicity testing. Consequently, we considered it important to expand the database to include substances that fail to elicit a positive response in the Ames test, i.e., Ames negative substances. Here, we describe a curated collection of 211 Ames negative substances, with a summary of complementary data available for other genotoxicity endpoints in vitro and in vivo, plus available carcinogenicity data. A descriptive analysis of the data is presented. This includes a representation of the chemical space formed by the Ames-negative database with respect to other substances (e.g. REACH registered substances, approved drugs, pesticides, etc.) and a description of the organic functional groups found in the database. We also provide some suggestions on further analyses that could be made.


Assuntos
Testes de Carcinogenicidade/normas , Carcinógenos/toxicidade , Bases de Dados Factuais/normas , Testes de Mutagenicidade/normas , Mutagênicos/toxicidade , Resultados Negativos/normas , Animais , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Gerenciamento de Dados/normas , Humanos
16.
Nucleic Acids Res ; 48(15): 8461-8473, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32633759

RESUMO

DNA polymerase ζ (Pol ζ) and Rev1 are essential for the repair of DNA interstrand crosslink (ICL) damage. We have used yeast DNA polymerases η, ζ and Rev1 to study translesion synthesis (TLS) past a nitrogen mustard-based interstrand crosslink (ICL) with an 8-atom linker between the crosslinked bases. The Rev1-Pol ζ complex was most efficient in complete bypass synthesis, by 2-3 fold, compared to Pol ζ alone or Pol η. Rev1 protein, but not its catalytic activity, was required for efficient TLS. A dCMP residue was faithfully inserted across the ICL-G by Pol η, Pol ζ, and Rev1-Pol ζ. Rev1-Pol ζ, and particularly Pol ζ alone showed a tendency to stall before the ICL, whereas Pol η stalled just after insertion across the ICL. The stalling of Pol η directly past the ICL is attributed to its autoinhibitory activity, caused by elongation of the short ICL-unhooked oligonucleotide (a six-mer in our study) by Pol η providing a barrier to further elongation of the correct primer. No stalling by Rev1-Pol ζ directly past the ICL was observed, suggesting that the proposed function of Pol ζ as an extender DNA polymerase is also required for ICL repair.


Assuntos
DNA Polimerase Dirigida por DNA/genética , DNA/genética , Nucleotidiltransferases/genética , Proteínas de Saccharomyces cerevisiae/genética , Estruturas Cromossômicas/efeitos dos fármacos , Estruturas Cromossômicas/genética , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/genética , Replicação do DNA/genética , Complexos Multiproteicos/genética , Compostos de Mostarda Nitrogenada/farmacologia , Saccharomyces cerevisiae/genética
17.
Nucleic Acids Res ; 48(15): 8490-8508, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32687193

RESUMO

Several functions have been proposed for the Escherichia coli DNA polymerase IV (pol IV). Although much research has focused on a potential role for pol IV in assisting pol III replisomes in the bypass of lesions, pol IV is rarely found at the replication fork in vivo. Pol IV is expressed at increased levels in E. coli cells exposed to exogenous DNA damaging agents, including many commonly used antibiotics. Here we present live-cell single-molecule microscopy measurements indicating that double-strand breaks induced by antibiotics strongly stimulate pol IV activity. Exposure to the antibiotics ciprofloxacin and trimethoprim leads to the formation of double strand breaks in E. coli cells. RecA and pol IV foci increase after treatment and exhibit strong colocalization. The induction of the SOS response, the appearance of RecA foci, the appearance of pol IV foci and RecA-pol IV colocalization are all dependent on RecB function. The positioning of pol IV foci likely reflects a physical interaction with the RecA* nucleoprotein filaments that has been detected previously in vitro. Our observations provide an in vivo substantiation of a direct role for pol IV in double strand break repair in cells treated with double strand break-inducing antibiotics.


Assuntos
Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , DNA Polimerase beta/ultraestrutura , Proteínas de Ligação a DNA/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/ultraestrutura , Exodesoxirribonuclease V/ultraestrutura , Recombinases Rec A/genética , Ciprofloxacino/farmacologia , Dano ao DNA/efeitos dos fármacos , DNA Polimerase beta/genética , Reparo do DNA/genética , Replicação do DNA/genética , Escherichia coli/genética , Escherichia coli/ultraestrutura , Exodesoxirribonuclease V/genética , Imagem Individual de Molécula
18.
Cancer Sci ; 111(9): 3111-3121, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32639661

RESUMO

Cancer cells are often characterized by abnormalities in DNA damage response including defects in cell cycle checkpoints and/or DNA repair. Synthetic lethality between DNA damage repair (DDR) pathways has provided a paradigm for cancer therapy by targeting DDR. The successful example is that cancer cells with BRCA1/2 mutations are sensitized to poly(adenosine diphosphate [ADP]-ribose)polymerase (PARP) inhibitors. Beyond the narrow scope of defects in the BRCA pathway, "BRCAness" provides more opportunities for synthetic lethality strategy. In human pancreatic cancer, frequent mutations were found in cell cycle and DDR genes, including P16, P73, APC, MLH1, ATM, PALB2, and MGMT. Combined DDR inhibitors and chemotherapeutic agents are under preclinical or clinical trials. Promoter region methylation was found frequently in cell cycle and DDR genes. Epigenetics joins the Knudson's "hit" theory and "BRCAness." Aberrant epigenetic changes in cell cycle or DDR regulators may serve as a new avenue for synthetic lethality strategy in pancreatic cancer.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias Pancreáticas/etiologia , Mutações Sintéticas Letais , Animais , Ciclo Celular/genética , Quimiorradioterapia , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Suscetibilidade a Doenças , Epigênese Genética/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/terapia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo , Transdução de Sinais
19.
Mutat Res ; 854-855: 503196, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32660820

RESUMO

DNA is exposed to the attack of several exogenous agents that modify its chemical structure, so cells must repair those changes in order to survive. Alkylating agents introduce methyl or ethyl groups in most of the cyclic or exocyclic nitrogen atoms of the ring and exocyclic oxygen available in DNA bases producing damage that can induce the SOS response in Escherichia coli and many other bacteria. Likewise, ultraviolet light produces mainly cyclobutane pyrimidine dimers that arrest the progression of the replication fork and triggers such response. The need of some enzymes (such as RecO, ExoI and RecJ) in processing injuries produced by gamma radiation prior the induction of the SOS response has been reported before. In the present work, several repair-defective strains of E. coli were treated with methyl methanesulfonate, ethyl methanesulfonate, mitomycin C or ultraviolet light. Both survival and SOS induction (by means of the Chromotest) were tested. Our results indicate that the participation of these genes depends on the type of injury caused by a genotoxin on DNA.


Assuntos
Reparo do DNA/efeitos dos fármacos , Reparo do DNA/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Mutagênicos/farmacologia , Resposta SOS em Genética/efeitos dos fármacos , Resposta SOS em Genética/genética , Alquilantes/farmacologia , Proteínas de Bactérias/genética , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Metanossulfonato de Etila/farmacologia , Metanossulfonato de Metila/farmacologia , Mitomicina/farmacologia , Dímeros de Pirimidina/farmacologia , Raios Ultravioleta/efeitos adversos
20.
Mutat Res ; 854-855: 503198, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32660822

RESUMO

TiO2 particles are broadly used in daily products, including cosmetics for their UV-absorbing property, food for their white colouring property, water and air purification systems, self-cleaning surfaces and photoconversion electrical devices for their photocatalytic properties. The toxicity of TiO2 nano- and microparticles has been studied for decades, and part of this investigation has been dedicated to the identification of their potential impact on DNA, i.e., their genotoxicity. This review summarizes data retrieved from their genotoxicity testing during the past 6 years, encompassing both in vitro and in vivo studies, mostly performed on lung and intestinal models. It shows that TiO2 particles, both nano- and micro-sized, produce genotoxic damage to a variety of cell types, even at low, realistic doses.


Assuntos
Mutagênicos/toxicidade , Titânio/toxicidade , Animais , DNA/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Humanos , Testes de Mutagenicidade/métodos
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