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During coal mining activities, many compounds are released into the environment that can negatively impact human health. Particulate matter, polycyclic aromatic hydrocarbons (PAHs), metals, and oxides are part of the complex mixture that can affect nearby populations. Therefore, we designed this study to evaluate the potential cytotoxic and genotoxic effects in individuals chronically exposed to coal residues from peripheral blood lymphocytes and buccal cells. We recruited 150 individuals who lived more than 20 years in La Loma-Colombia and 120 control individuals from the city of Barranquilla without a history of exposure to coal mining. In the cytokinesis-block micronucleus cytome (CBMN-Cyt) assay, significant differences in the frequency of micronucleus (MN), nucleoplasmic bridge (NPB), nuclear bud (NBUD), and apoptotic cells (APOP) were observed between the two groups. In the buccal micronucleus cytome (BM-Cyt) assay, a significant formation of NBUD, karyorrhexis (KRX), karyolysis (KRL), condensed chromatin (CC), and binucleated (BN) cells was observed in the exposed group. Considering the characteristics of the study group, a significant correlation for CBMN-Cyt was found between NBUD and vitamin consumption, between MN or APOP and meat consumption, and between MN and age. Moreover, a significant correlation for BM-Cyt was found between KRL and vitamin consumption or age, and BN versus alcohol consumption. Using Raman spectroscopy, a significant increase in the concentration of DNA/RNA bases, creatinine, polysaccharides, and fatty acids was detected in the urine of individuals exposed to coal mining compared to the control group. These results contribute to the discussion on the effects of coal mining on nearby populations and the development of diseases due to chronic exposure to these residues.

Introduction: Breast cancer is the object of thousands of studies worldwide. Nevertheless, few tools are available to corroborate prediction of response to neoadjuvant chemotherapy. Artificial intelligence is being researched for its potential utility in several fields of knowledge, including oncology. The development of a standardized Artificial intelligence-based predictive model for patients with breast cancer may help make clinical management more personalized and effective. We aimed to apply Artificial intelligence models to predict the response to neoadjuvant chemotherapy based solely on clinical and pathological data. Methods: Medical records of 130 patients treated with neoadjuvant chemotherapy were reviewed and divided into two groups: 90 samples to train the network and 40 samples to perform prospective testing and validate the results obtained by the Artificial intelligence method. Results: Using clinicopathologic data alone, the artificial neural network was able to correctly predict pathologic complete response in 83.3% of the cases. It also correctly predicted 95.6% of locoregional recurrence, as well as correctly determined whether patients were alive or dead at a given time point in 90% of the time. To date, no published research has used clinicopathologic data to predict the response to neoadjuvant chemotherapy in patients with breast cancer, thus highlighting the importance of the present study. Conclusions: Artificial neural network may become an interesting tool for predicting response to neoadjuvant chemotherapy, locoregional recurrence, systemic disease progression, and survival in patients with breast cancer.

Welding fumes are classified as carcinogenic to humans. The aim of the present study was to measure buccal micronucleus cytome assay biomarkers and to evaluate their association with inorganic elements and genetic polymorphisms (XRCC1, OGG1, XRCC3, GSTM1, and GSTT1) in welders (n = 98) and control individuals (n = 100). Higher levels of DNA damage and cell death were observed in the exposed group. Also, a significant correlation between the frequency of micronuclei and Na, Si, Cl, Ti, Cr, Zn and Mg concentrations. The formation of micronuclei, binucleated cells, cell death was associated with polymorphisms in repair pathways. The OGG1Ser326Cys and XRCC3 241Thr/Met genotypes were associated with cell death. Individuals with GSTM1 null genotype had a higher frequency of micronuclei. These results demonstrate that the deleterious effects of exposure to welding fumes are exacerbated by lifestyle habits, and genetic polymorphisms can influence DNA damage and cell death.

Nanoparticles such as zinc oxide nanoparticles (ZnO-NP) that are incorporated in consumer and industrial products have caused concern about their potential ecotoxicological impact when released into the environment. Bivalve mollusks are susceptible targets for nanoparticle toxicity since nanomaterials can enter the cells by endocytosis mechanisms. The aim of this study was to evaluate the influence of ZnO-NP on the redox metabolism in Limnoperna fortunei and the DNA damage after exposure to ZnO-NP. Adult bivalves were incubated with 1-, 10-, and 50-μg mL-1 ZnO-NP for 2, 4, and 24 h. Ionic Zn release, enzymatic and non-enzymatic antioxidant activity, oxidative damage, and DNA damage were evaluated. Oxidative damage to proteins and lipids were observed after 4-h exposure and returned to baseline levels after 24 h. Superoxide dismutase levels decreased after 4-h exposure and increased after 24 h. No significant alteration was observed in the catalase activity or even DNA double-strand cleavage. The dissociation of ZnO may occur after 24 h, releasing ionic zinc (Zn2+) by hydrolysis, which was confirmed by the increase in the ionic Zn concentration following 24-h exposure. In conclusion, ZnO-NP were able to induce oxidative stress in exposed golden mussels. The golden mussel can modulate its own antioxidant defenses in response to oxidative stress and seems to be able to hydrolyze the nanoparticles and consequently, release Zn2+ into the cellular compartment.

Gold nanoparticles (GNPs) are often used in numerous applications, including diagnostics, drug delivery and treatment of diseases, given its physical features and excellent biocompatibility, where factors such as dispersion and stability are directly related to the its performance and efficiency. Mathematical models for experimental design can be very useful and contribute to predict optimal functionalization strategies. Therefore, the purpose of this work was to stabilize and functionalize GNPs of 40 nm and 80 nm and determine optimal concentrations of heterobifunctional polyethylene glycols (HS-PEG-NH2 3500 and 7500 g/mol). Mathematical models relating particle diameter, initial concentration and quantification of the polymers adsorbed for both varieties of thiol PEG was predicted. GNP were modified and subjected to the four different strategies employed in this study (strategy I and III with HS-PEG-NH2 3500; II and IV with HS-PEG-NH2 7500). Solutions with concentrations ranging from 30 to 200 ng/ml of enzyme horseradish peroxidase (HRP) were used as an alternative to gauge the efficiency of the evaluated strategies. A superior yield and efficacy of strategies I and II was observed, since the former had a capture capacity of up to 5 times when stabilized for 2 h and up to 6 times for 12 h. Regarding stability, the most promising strategy observed was number II for nanoparticles of 40 nm. Moreover, the mathematical models highlighted in this study were efficient in predicting behavior of colloidal solutions with sizes of 40 nm and 80 nm when in contact with different varieties of thiol PEG and may exempt new kinetic tests.

Tellurium is a rare element that has been regarded as a toxic, nonessential element, and its biological role is not clearly established. In addition, the biological effects of elemental tellurium and some of its organic and inorganic derivatives have been studied, leading to a set of interesting and promising applications. Diphenyl ditelluride (DPDT), an organic tellurium derivate, showed antioxidant, antigenotoxic, antimutagenic, and anticancer properties. The antioxidant and prooxidant properties of DPDT are complex and depend on experimental conditions, which may explain the contradictory reports of these properties. In addition, DPDT may exert its effects through different pathways, including distinct ones to those responsible for chemotherapy resistance phenotypes: transcription factors, membrane receptors, adhesion, structural molecules, cell cycle regulatory components, and apoptosis pathways. This review aims to present recent advances in our understanding of the biological effects, therapeutic potential, and safety of DPDT treatment. Moreover, original results demonstrating the cytotoxic effects of DPDT in different mammalian cell lines and systems biology analysis are included, and emerging approaches for possible future applications are inferred.

Ultra-high molecular weight polyethylene (UHMWPE) is a prevailing bearing material applied in joint arthroplasty. Despite not being a novel biomaterial, its debris as consequence of long application and surface properties usually still lead to short lifespan. Many of the drawbacks are associated with sterilization methods that degrade the surface properties of UHMWPE. This work aims at improving the sterilizing treatment and also increasing material wettability, without losing bulk properties, which are essential for an orthopedic bearing. Cold plasma in hollow cathode setting was used for the material surface functionalization. Samples were characterized through contact angle (WCA), x-ray diffraction (XRD), optical microscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and profilometry. Optimal points based on immediate surface wettability, shelf time and sterilization efficacy were chosen for biocompatibility evaluation. When comparing cell viability through MTT among treated samples (OP1, OP2 and UV), a slight reduction in OP2 viability could be seen after 7 days incubation, which is also observed in Giemsa staining and SEM images. In late incubation, OP1 loses its hydrophilic character and displays higher cell adhesion than its counterparts UV and OP2. At the end, OP2 showed less cells growing over the biomaterial after 7 days exposition compared to OP1 and UV. OP1 presented a more hydrophobic surface and improved cell adhesion, differently from OP2 and UV, which maintained their wettability conditions in late incubation. Cell analysis results indicate that surface wetting influences cell morphology and consequent cell adhesion, in which more hydrophobic surfaces are shown to favor fibroblast adhesion properties.

Background/Aim: Antarctic seaweeds are considered a promising source of compounds with anticancer activity. Colorectal cancer (CRC) is one of the most incident cancers with high mortality rates worldwide. This work aimed to characterize chemically extracts of the Antarctic macroalgae Iridaea cordata, Cystosphaera jacquinotii and Desmarestia anceps and to evaluate the cytotoxic effects against human colon cancer HCT 116 cell line. Materials and Methods: The extracts were obtained by depletion using an ultrasound probe and were identified by High-Performance Liquid Chromatography (HPLC) and Gas Chromatography coupled with Mass Spectrometry (GC-MS). Cell viability was determined by MTT assay. Results: Hexanic and chloroform extracts of the I. cordata and the hexanic, chloroform and methanolic extracts of D. anceps were able to inhibit growth of colorectal cancer cells in the three different incubation times (24, 48 and 72 h). Through GC analysis, 01 compounds were identified in the hexane extract and 02 compounds in the chloroform extract of the algae I. cordata. The hexane extract of D. anceps macroalgae presented 5 compounds, chloroform extract 10 and methanolic extract 3 respectively, with special highlight to fucosterol. Carotenoid analysis by HPLC identified β-carotene in all species, while zeaxanthin was present in the spectrum of I. cordata and C. jacquinotii. Fucoxanthin and violaxanthin were confirmed in the brown seaweeds C. jacquinotii and D. anceps. Conclusion: Extracts of macroalgae I. Cordata and D. anceps may be a source of therapeutic agents against CRC.

Red propolis is a natural resin mixture produced by honeybees and presents a source of active compounds with a variety of biological activities. In this study, we describe the chemical characterization and potential antitumor activity of total extract of Brazilian red propolis and its fractions. Fractions were obtained through column chromatography revealing 14 different compounds in all samples, which were determined and distinguished of other isobar molecules by fragmentation pathways by ESI-MS/MS in positive mode. Some molecules as cis-asarone or trans-isoelemicin were identified and distinguish from elemicin compound and vestitol or isovestitol were also distinguished from neovestitol by fragmention pathway. Other important compounds as liquiritigenin was differentiated from isoliquiritigenin and formononetin from dalbergin.MTT viability assay showed different toxicity in cell lines after exposition to total extract and fractions. Fractions 05 and 06 had more selectivity against HT-29 and HCT-116 cancer cells, respectively, in relation to normal cells. IC50 (ranging of 72.45 ± 6.57 to 73.58 ± 1.00 μg/mL) in cancer cells were lower than reported in total extracts of propolis. May-Grunwald/Giemsa staining revealed cellular morphological changes after exposition to higher concentrations of red propolis extracts. Fractionation techniques can contribute to reduce chemical diversity verified in propolis mixtures, generating fractions with improved biological activity and contributing to the development of new strategies for discovery of natural compounds against cancer. Keywords: Propolis, Fractionation, Natural compounds, Cytotoxicity, Cancer

Alkylating agents damage DNA and proteins and are widely used in cancer chemotherapy. While the cellular responses to alkylation-induced DNA damage have been explored, knowledge of how alkylation damage affects global cellular stress responses is still sparse. Here, we examined the effects of the alkylating agent methylmethane sulfonate (MMS) on gene expression in mouse liver taking advantage of mice deficient in alkyladenine DNA glycosylase (Aag), the enzyme that initiates the repair of alkylated DNA bases. MMS induced a robust transcriptional response in wild-type liver that included markers of the endoplasmic reticulum (ER) stress/unfolded protein response (UPR) known to be controlled by the transcription factor XBP1, a key UPR effector. Importantly, this response is significantly reduced in the Aag knockout. To investigate a potential role for AAG in alkylation-induced UPR, the expression of UPR markers after MMS treatment was interrogated in human glioblastoma cell lines expressing different AAG levels. Alkylation induced the UPR in cells expressing AAG; conversely, AAG knock-down compromised UPR induction and led to a defect in XBP1 activation plus a decrease in the expression of the ER chaperone BiP. To verify that the DNA repair activity of AAG is required for this response, AAG knockdown cells were complemented with wild-type Aag or with a mutant version of the Aag gene producing a glycosylase-deficient AAG protein. As expected, the glycosylase-defective mutant Aag does not fully protect AAG knockdown cells against MMS-induced cytotoxicity. Remarkably, however, alkylation-induced XBP1 activation is fully complemented by the catalytically inactive AAG enzyme. This work establishes that, in addition to its enzymatic activity, AAG has non-canonical functions in alkylation-induced UPR that contribute to the overall cellular response to alkylation.Significance StatementStress response pathways, such as the DNA damage response (DDR) and the UPR, are critical in both the etiology and treatment of cancer and other chronic diseases. Knowledge of an interplay between ER stress and genome damage repair is emerging, but evidence linking defective DNA repair and impaired ER stress response is lacking. Here, we show that AAG is necessary for UPR activation in response to alkylating agents. AAG-deficient mice and human cancer cells are impaired in alkylation-induced UPR. Strikingly, this defect can be complemented by an AAG variant defective in glycosylase activity. Our studies suggest AAG has non-canonical functions and identify AAG as a point of convergence for stress response pathways. This knowledge could be explored to improve cancer treatment.

Nanoparticles incorporated in consumer and industrial products cause concerns about their potential ecological impacts. Zinc oxide nanoparticles (ZnO-NP) have several applications, which increases their potential for release to the environment, causing ecotoxicological problems. Bivalve mollusks are susceptible targets for nanoparticles toxicity, since nanomaterials can enter the cells by endocytosis mechanisms. Limnoperma fortunei (golden mussel) are validated for biomonitoring purposes and have a wide distribution in the South of Brazil, where it can be collected throughout the year. The aim of this study was to evaluate the influence of ZnO-NP on the redox metabolism by enzymatic and non-enzymatic antioxidant defense assessment in addition to DNA damage by DNA fragmentation assay in L. fortunei after exposure to ZnO-NP. Adult bivalves were placed in contact with 1, 10, and 50 µg mL-1 ZnO-NP during three incubation times: 2, 4 and 24 h. Ionic Zn release, enzymatic and non-enzymatic antioxidant activity, oxidative damage to lipids and proteins and DNA damage were evaluated. Oxidative damage to proteins and lipids were observed after 4 h exposure and returned to baseline levels after 24 h. Superoxide dismutase levels decreased after 4 h exposure and increased after 24 h. No significant alteration was observed in catalase activity or even DNA double strand cleavage. The dissociation of ZnO may occur after 24 h, releasing ionic zinc (Zn2+) by hydrolysis, which was confirmed as the ionic Zn concentration increased following 24 h exposure. In conclusion, ZnO-NP were able to induce oxidative stress in exposed golden mussels. The golden mussel is capable to modulate its own antioxidant defences in response to oxidative stress and seems to be able to hydrolyse the nanoparticle and consequently release Zn2+ into the cellular compartment.

Due to the high rate of transmissibility, Brazil became the new COVID-19 outbreak epicenter, being a reference region to monitor how SARS-CoV-2 is mutating and spreading. Here, we combined genomic and structural biology analysis evaluate genomes isolated from different regions of Brazil. We showed that the most prevalent mutations were located in the S, N, ORF3a and ORF6 genes, which are involved in different stages of viral life cycle and its interaction with the host cells. Structural analysis brought to light the positions of these mutations on protein structures, helping studies of structure-based drug discovery and vaccine development.

In this work, NRL films were enriched with red propolis and silver nanoparticles with the aim of obtaining dressings with bactericide properties. To improve the properties of these materials, plasma treatment was also applied to the films. Cytotoxic effects were evaluated by MTT and agar diffusion assays on secondary and stem cells. Determination of cell behavior on the films were assessed by EDS and FEG-SEM. In general, the plasma modified NRL films presented hydrophilic character, favorable condition for biomedical applications. RBS results showed that silver is probably in nanoparticulate form. MTT assays revealed that non-cytotoxic effects were observed for all the samples extracts. Either the plasma treatment or silver deposition were effective in sterilizing the samples and modifying their surfaces. It was demonstrated in this in vitro study that ADSCs associated with NRL films enriched with propolis should be considered promising for application in the healing of occlusive wounds.

Neurodegenerative diseases (NDs) represent one of the most important public health problems, and worldwide, hundreds of millions of people are affected by NDs, displaying strong evidence to these diseases is one of the most significant challenges to public health. Neurological disorders include several common diseases of the central and peripheral nervous system such as Alzheimer's disease and other dementia, epilepsy, headache disorders, multiple sclerosis, Parkinson's disease, and others. The discovery of substances capable of preventing or treating neurological disorders has been the goal of researchers for several years. New therapies and new molecules should be explored. In this context, natural compounds represent an important source for the development of new drugs. For example, between 1981 and 2014, from a total of 12 new approved molecules for the treatment of Parkinson's disease, only one was a synthetic drug, being the others biological, derived or inspired in a natural product. In the same line, > 50% of all new antidepressant molecules were synthetic/mimetic of a natural product. Anticholinesterases like physostigmine and neostigmine, opioids alkaloids, galantamine, are some examples of drugs utilized from derived plants for the treatment of neurological disorders, highlighting the relevance of studying and searching for new natural products for the treatment of neurological disorders. This chapter aimed to summarize the most important compounds originated from natural sources that were targets of clinical studies, associated with neurological and psychiatric disorders, obtaining a total of 13 articles, in the last 10 years. Also, we characterized these compounds structurally. Considering the vast diversity of plants, few herbal medicines or botanical drugs were approved for human use, in the last centuries, only few innovative therapeutic products have been developed, especially in the field of neurological diseases.

Ti6Al4V used in biomedical applications still has several surface-related problems, such as poor bone compatibility and low wear resistance. In this work, the formation of a protective layer of titanium nitride obtained by plasma treatment in hollow cathode was studied, and the best experimental conditions were verified by a statistical factorial design of experiments. The samples were characterized in terms of their physical and chemical properties, correlating the effects of time (min) and temperature (°C). An achieved ideal condition was further analysed in terms of in vitro cytotoxicity, micro-abrasion, and electrochemical properties. The carried-out assessment has shown that nitrided condition has an improvement in wettability, microhardness, along with TixNy formation and roughness increment, when compared to pristine condition.

The immunomodulatory properties of Brazilian red propolis (BRP) have been already described. Also, propolis have been proved to have antibacterial activity on Corynebacterium pseudotuberculosis. An adjuvant effect of red propolis oil was able to induce a significant anti-C. pseudotuberculosis humoral immune response. Here, we demonstrate for the first time the immunostimulant property of BRP hydroalcoholic extract (BRPHE) in a recombinant vaccine against caseous lymphadenitis. Mice BALB/c were allocated in three groups inoculated with: sterile saline solution (G1); BRPHE (G2); or BRPHE combined with the C. pseudotuberculosis rCP01850 recombinant protein (G3) in two doses within a 21-days-interval. Blood samples were collected for the total IgG, IgG1 and IgG2a measurement. Mice were challenged with a virulent C. pseudotuberculosis strain, and other 6 mice were used for IFN-γ and IL-10 levels determination after splenocyte stimulation with the recombinant antigen. G3 showed higher significant levels of antibodies on the 42nd experimental day, with a high IgG2a/IgG1 proportion. G2 and G3 presented significant production of IFN-γ and IL-10, while G3 presented the higher levels of IFN-γ (p 0.05). After challenge, G2 showed a survival rate of 20%, while 70% of mice from G3 survived the experimental challenge. In conclusion, BRPHE used alone has immunostimulant properties specially on cellular immune response, and when used in combination with the recombinant protein rCP01850 induces cellular and humoral immune responses as well as a significant survival of inoculated mice.

Continuous exposure to coal mining particles can cause a variety of lung diseases. We aimed to evaluate the outcomes of exposure to detailed characterized coal and coal fly ash (CFA) particles on DNA, lung and extrapulmonary tissues. Coal samples (COAL11 and COAL16) and CFA samples (CFA11 and CFA16) were included in this study. Intending to enhance the combustion process COAL16 was co-fired with a mixture of fuel oil and diesel oil, producing CFA16. Male BALB/c mice were intratracheally instilled with coal and CFA particles. Measurements were done 24 h later. Results showed significant rigidity and obstruction of the central airways only for animals acutely exposed to coal particles. The COAL16 group also showed obstruction of the peripheral airways. Mononuclear cells were recruited in all treatment groups and expression of cytokines, particularly TNF-α and IL-1β, was observed. Only animals exposed to COAL16 showed a significant expression of IL-6 and recruitment of polymorphonuclear cells. DNA damage was demonstrated by Comet assay for all groups. Cr, Fe and Ni were detected in liver, spleen and brain, showing the efficient translocation of metals from the bloodstream to extrapulmonary organs. These effects were associated with particle composition (oxides, hydroxides, phosphates, sulfides, sulphates, silciates, organic-metalic compounds, and polycyclic aromatic hidrocarbons) rather than their size. This work provides state of knowledge on the effects of acute exposure to coal and CFA particles on respiratory mechanics, DNA damage, translocation of metals to other organs and related inflammatory processes.

Epidemiological studies indicate that living in proximity to coal mines is correlated with numerous diseases including cancer, and that exposure to PM10 and PM2.5 components could be associated with this phenomenon. However, the understanding of the mechanisms by which PM exerts its adverse effects is still incomplete and comes mainly from studies in occupationally exposed populations. The aims of this study were to: (1) evaluate DNA damage in lymphocytes assessing the cytokinesis-block micronucleus cytome assay (CBMN-cyt) parameters; (2) identify aneugenic or clastogenic effects in lymphocytes of exposed populations using CREST immunostaining for micronuclei; (3) evaluate multi-elemental composition of atmospheric particulate matter; and (4) verify relation between the DNA damage and PM2.5 and PM10 levels around the mining area. Analysis revealed a significant increase in micronuclei frequency in binucleated (MNBN) and mononucleated (MNMONO) cells of individuals with residential proximity to open-pit coal mines compared to residents from non-mining areas. Correlation analysis demonstrated a highly significant association between PM2.5 levels, MNBN frequencies and CREST+ micronuclei induction in exposed residents. These results suggest that PM2.5 fraction generated in coal mining activities may induce whole chromosome loss (aneuploidy) preferentially, although there are also chromosome breaks. Analysis of the chemical composition of PM2.5 by PIXE demonstrated that Si, S, K and Cr concentrations varied significantly between coal mining and reference areas. Enrichment factor values (EF) showed that S, Cr and Cu were highly enriched in the coal mining areas. Compared to reference area, mining regions had also higher concentrations of extractable organic matter (EOM) related to nonpolar and polar compounds. Our results demonstrate that PM2.5 fraction represents the most important health risk for residents living near open-pit mines, underscoring the need for incorporation of ambient air standards based on PM2.5 measures in coal mining areas.

Sterilization is one of the last stages prior to the implantation of a biomaterial. Therefore, the method should be chosen carefully as this is determinant not to compromise the properties of the material. In this context, three sterilization processes were evaluated as to their effect on the properties of a silane hybrid coating: steam autoclave, ethylene oxide, and hydrogen peroxide plasma. The coating was obtained from a sol consisting of alkoxysilane Tetraethoxysilane and organoalcoxysilane Methyltriethoxysilane (MTES), applied to the Ti6Al4V substrate, to increase its corrosion resistance and biocompatibility. After sterilization, the samples were characterized by scanning electron microscopy, atomic force microscopy, profilometry, wetabillity, and Fourier transform infrared spectroscopy. The electrochemical behavior was monitored by open circuit potential and potentiodynamic polarization curves. The cytocompatibility was evaluated by adhesion, viability, and morphological alterations in the MG-63 cells. The results showed that the protective behavior of the hybrid coating was compromised regardless of the sterilization method. However, the steam autoclave caused more morphological changes on the silane hybrid coating as well as on the Ti6Al4V substrate than the other two sterilization methods. Although the sterilized hybrid coating did not show cytotoxicity, the hybrid coating sterilized by hydrogen peroxide plasma showed a higher percentage of viable cells. The ethylene oxide presented the lowest percentage of viability and the highest cell death rate.

The sodium valproate has been largely used as an anti-epilepsy drug and, recently, as a putative drug in cancer therapy. However, the treatment with sodium valproate has some adverse effects. In this sense, more effective and secure complexes than sodium valproate should be explored in searching for new active drugs. This study aims to evaluate the cytotoxicity of sodium valproate, mixed ternary mononuclear Cu(II) complexes based on valproic acid (VA) with 1,10-phenanthroline (Phen) or 2,2’- bipyridine (Bipy) ligands - [Cu2(Valp)4], [Cu(Valp)2Phen] and [Cu(Valp)2Bipy] - in yeast Saccharomyces cerevisiae, proficient or deficient in different repair pathways, such as base excision repair (BER), nucleotide excision repair (NER), translesion synthesis (TLS), DNA postreplication repair (PRR), homologous recombination (HR) and non-homologous end-joining (NHEJ). The results indicated that the Cu(II) complexes have higher cytotoxicity than sodium valproate in the following order: [Cu(Valp)2Phen] > [Cu(Valp)2Bipy] > [Cu2(Valp)4] > sodium valproate. The treatment with Cu(II) complexes and sodium valproate induced mutations in S. cerevisiae. The data indicated that yeast strains deficient in BER (Ogg1p), NER (complex Rad1p-Rad10p) or TLS (Rev1p, Rev3p and Rad30p) proteins are associated with increased sensitivity to sodium valproate. The BER mutants (ogg1Δ, apn1Δ, rad27Δ, ntg1Δ and ntg2Δ) showed increased sensitivity to Cu(II) complexes. DNA damage induced by the complexes requires proteins from NER (Rad1p and Rad10p), TLS (Rev1p, Rev3p and Rad30p), PRR (Rad6 and Rad18p) and HR (Rad52p and Rad50p) for efficient repair. Therefore, Cu(II) complexes display enhanced cytotoxicity when compared to the sodium valproate and induce distinct DNA lesions, indicating a potential application as cytotoxic agents.

Eukaryote initiation factor 2 subunit β (eIF2β) plays a crucial role in regulation protein synthesis, which mediates the interaction of eIF2 with mRNA. eIF2β contains evolutionarily conserved polylysine stretches in amino-terminal region and a zinc finger motif in the carboxy-terminus.The gene eIF2β was cloned under tetracycline transcription control and the polylysine stretches were deleted by site-directed mutagenesis (eIF2βΔ3K). The plasmid was transfected into HEK 293 TetR cells. These cells were analyzed for their proliferative and translation capacities as well as cell death rate. Experiments were performed using gene reporter assays, western blotting, flow cytometry, cell sorting, cell proliferation assays and confocal immunofluorescence.eIF2βΔ3K affected negatively the protein synthesis, cell proliferation and cell survival causing G2 cell cycle arrest and increased cell death, acting in a negative dominant manner against the native protein. Polylysine stretches are also essential for eIF2β translocated from the cytoplasm to the nucleus, accumulating in the nucleolus and eIF2βΔ3K did not make this translocation.eIF2β is involved in the protein synthesis process and should act in nuclear processes as well. eIF2βΔ3K reduces cell proliferation and causes cell death. Since translation control is essential for normal cell function and survival, the development of drugs or molecules that inhibit translation has become of great interest in the scenario of proliferative disorders. In conclusion, our results suggest the dominant negative eIF2βΔ3K as a therapeutic strategy for the treatment of proliferative disorders and that eIF2β polylysine stretch domains are promising targets for this.

Vitis labrusca L. is the main species used for wine and juice production in Brazil. The grapevine leaves can be used both as functional foods and as cheapest sources for the extraction of phenolic compounds. Besides the antioxidant activity, grapevine leaves exhibited significant anti-inflammatory activity. Therefore, the aim of this study was to develop and validate an analytical methodology to determine the metals selenium (96Se), chromium (53Cr), nickel (62Ni), cadmium (111Cd) and lead (206Pb) in 30 samples of grapevine leaf extracts (Vitis labrusca, Bordo cultivar) using inductively coupled plasma mass spectrometry (ICP-MS). To obtain the grapevine leaf extracts the samples were milled, weighed and digested in microwave oven with nitric acid. The method showed linearity, precision, accuracy and limits of quantification and detection acceptable for INMETRO protocol validation of analytical methods. Therefore, the method using ICP-MS was developed and validated to determine metals concentrations in grapevine leaves of Vitis labrusca L. and the proposed method could be applied in routine analytical laboratory.

Grapes are one of the most commonly consumed fruit, in both fresh and processed forms; however, a significant amount is disposed of in the environment. Searching for a use of this waste, the antigenotoxic, antimutagenic, and antioxidant activities of aqueous extracts from organic and conventional Vitis labrusca leaves were determined using V79 cells as model. The antigenotoxic activity was analyzed by the alkaline comet assay using endonuclease III and formamidopyrimidine DNA glycosylase enzymes. The antimutagenic property was assessed through the micronucleus (MN) formation, and antioxidant activities were assessed using 2',7'-dichlorodihydrofluorescin diacetate (DCFH-DA) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH(●)) radical scavenging, as well as with superoxide dismutase (SOD) and catalase (CAT) activity assays. In addition, phenolic content and ascorbic acid levels of both extracts were determined. Data showed that both organic and conventional grapevine leaves extracts possessed antigenotoxic and antimutagenic properties. The extract of organic leaves significantly reduced intracellular reactive oxygen species (ROS) levels in V79 cells, and displayed greater ability for DPPH(●) scavenging and higher SOD and CAT activities than extract from conventional leaves. Further, the extract from organic leaves contained higher phenolic and ascorbic acid concentrations. In summary, extracts from organic and conventional grape leaves induced important in vitro biological effects.

Vaccinium corymbosum (L.) varieties cultivation is relatively recent in Brazil, but its production has been intensified given its good adaptability to the Southern Brazil climate. Blueberries are a rich source of phenolic compounds and contain significant levels of anthocyanins, flavonols, chlorogenic acids, and procyanidins, which lead to different biological activities. Chemical identification of skin and whole hydroalcoholic blueberry extracts (ExtSB and ExtWB) revealed the presence of anthocyanins concentrated in the skin and others chemicals compounds as quercetin glycosides, proanthocyanins dimers, citric, and chlorogenic acid in the pulp. Selectivity for tumor cell lines (Hep-2, HeLa, HT-29) using ExtSB and ExtWB extracts was observed through MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay after 24 h of treatment when compared to nontumor cells (MRC-5). Morphological changes and late stages of apoptotic and necrosis process were seen in HT-29 cell line after ExtWB treatment, compared to nontumor cell line MRC-5. These results are in agreement with other studies that indicate the activity of compounds such as anthocyanins and other molecules found in Southern Highbush blueberry variety, attributed to promote beneficial effects on health that may respond as cytotoxic natural agent and contribute to cancer treatment.

TiO 2 nanoparticles (TiO 2 -NP) have been incorporated into a large range of materials for different applications in the last decades and are very likely to appear in wastewater and effluents, eventually reaching the aquatic environment. Therefore, the assessment of the biological impact of TiO 2 -NP on aquatic ecosystem is of a major concern. The mussels represent a target group for TiO 2 -NP toxicity, as they are filter feeders and are capable of bioaccumulating toxic compounds. Furthermore, the exotic organism Limnoperna fortunei , golden mussel, is a freshwater bivalve that has been used in biomonitoring environmental conditions. In this work, the TiO 2 -NP’s ability to interact with haemocytes of golden mussel was assessed by transmission electron microscopy. The enzymatic and non-enzymatic antioxidant defenses were evaluated by superoxide dismutase (Sod) and catalase (Cat) activities and protein sulfhydryl content, which were measured after the golden mussel was exposed to TiO 2 -NP (1, 5, 10 and 50 μg mL −1 ). Results demonstrate that TiO 2 -NP was internalized by cells, causing alterations in haemocytes membrane. Antioxidant activity of Sod and Cat decreased after 2 h TiO 2 -NP exposure. After 4 h exposure, the enzymatic antioxidant activity was restored. Notably, the protein sulfhydryl content decreased after 2 h to all the TiO 2 -NP concentrations and no alterations were observed after 4 h of TiO 2 -NP exposure. These results demonstrate the potential of golden mussel as sentinel organism to TiO 2 -NP exposure.

Magneto-elastic materials (ME) have important advantages when applied as biosensors due to the possibility of wireless monitoring. Commercial Metglas 2826MB3™ (FeNiMoB) is widely used, however sensor stabilization is an important factor for biosensor performance. This study compared the effects of biocompatibility and degradation of the Metglas 2826MB3™ alloy, covered or not with a gold layer, when in contact with cell culture medium. Strips of amorphous Metglas 2826MB3™ were cut and coated with thin layers of Cr and Au, as verified by Rutherford Backscattering Spectroscopy (RBS). Using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES), the presence of metals in the culture medium was quantitatively determined for up to seven days after alloy exposure. Biocompatibility of fibroblast Chinese Hamster Ovary (CHO) cultures was tested and cytotoxicity parameters were investigated by indirect means of reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) at 1, 2 and 7 days. Cell death was further evaluated through in situ analysis using Acridine Orange/Ethidium Bromide (AO/EB) staining and images were processed with ImageJ software. Ions from Metglas(®) 2826MB3™ induced a degradation process in living organisms. The cytotoxicity assay showed a decrease in the percentage of live cells compared to control for the ME strip not coated with gold. AO/EB in situ staining revealed that most of the cells grown on top of the gold-covered sensor presented a normal morphology (85.46%). Covering ME sensors with a gold coating improved their effectiveness by generating protection of the transducer by reducing the release of ions and promoting a significant cell survival.

Anthracyclines, e.g., doxorubicin (DOX), and anthracenediones, e.g., mitoxantrone (MTX), are drugs used in the chemotherapy of several cancer types, including solid and non-solid malignancies such as breast cancer, leukemia, lymphomas, and sarcomas. Although they are effective in tumor therapy, treatment with these two drugs may lead to side effects such as arrhythmia and heart failure. At the same clinically equivalent dose, MTX causes slightly reduced cardiotoxicity compared with DOX. These drugs interact with iron to generate reactive oxygen species (ROS), target topoisomerase 2 (Top2), and impair mitochondria. These are some of the mechanisms through which these drugs induce late cardiomyopathy. In this review, we compare the cardiotoxicities of these two chemotherapeutic drugs, DOX and MTX. As described here, even though they share similarities in their modes of toxicant action, DOX and MTX seem to differ in a key aspect. DOX is a more redox-interfering drug, while MTX induces energy imbalance. In addition, DOX toxicity can be explained by underlying mechanisms that include targeting of Top2 beta, mitochondrial impairment, and increases in ROS generation. These modes of action have not yet been demonstrated for MTX, and this knowledge gap needs to be filled.

// Michelle Lima 1, 2, * , Hana Bouzid 1, * , Daniele G. Soares 1, 3 , Frederic Selle 3 , Claire Morel 1 , Carlos M. Galmarini 4 , Joao A. P. Henriques 2, 5 , Annette K. Larsen 1 , Alexandre E. Escargueil 1 1 Cancer Biology and Therapeutics, Centre de Recherche Saint-Antoine, Institut National de la Sante et de la Recherche Medicale (INSERM) UMR 938, Institut Universitaire de Cancerologie (IUC), Universite Pierre et Marie Curie (UPMC), Sorbonne Universites, Paris, France 2 Departamento de Biofisica, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil 3 Medical Oncology Department, Hospital Tenon, Public Assistance Hospitals of Paris (AP-HP), Alliance Pour la Recherche en Cancerologie (APREC), Paris, France 4 Cell Biology Department, PharmaMar, Poligono Industrial La Mina, Colmenar Viejo, Madrid, Spain 5 Instituto de Biotecnologia, Universidade de Caxias do Sul, Caxias do Sul, RS, Brazil * These authors contributed equally to this work Correspondence to: Alexandre E. Escargueil, email: Alexandre.Escargueil@inserm.fr Keywords: DNA double strand breaks, DNA alkylators, DNA replication, homologous recombination, checkpoint abrogators Received: November 29, 2015 Accepted: March 04, 2016 Published: March 23, 2016 ABSTRACT Trabectedin (Yondelis ® , ecteinascidin-743, ET-743) is a marine-derived natural product approved for treatment of advanced soft tissue sarcoma and relapsed platinum-sensitive ovarian cancer. Lurbinectedin is a novel anticancer agent structurally related to trabectedin. Both ecteinascidins generate DNA double-strand breaks that are processed through homologous recombination repair (HRR), thereby rendering HRR-deficient cells particularly sensitive. We here characterize the DNA damage response (DDR) to trabectedin and lurbinectedin in HeLa cells. Our results show that both compounds activate the ATM/Chk2 (ataxia-telangiectasia mutated/checkpoint kinase 2) and ATR/Chk1 (ATM and RAD3-related/checkpoint kinase 1) pathways. Interestingly, pharmacological inhibition of Chk1/2, ATR or ATM is not accompanied by any significant improvement of the cytotoxic activity of the ecteinascidins while dual inhibition of ATM and ATR strongly potentiates it. Accordingly, concomitant inhibition of both ATR and ATM is an absolute requirement to efficiently block the formation of γ -H2AX, MDC1, BRCA1 and Rad51 foci following exposure to the ecteinascidins. These results are not restricted to HeLa cells, but are shared by cisplatin-sensitive and -resistant ovarian carcinoma cells. Together, our data identify ATR and ATM as central coordinators of the DDR to ecteinascidins and provide a mechanistic rationale for combining these compounds with ATR and ATM inhibitors.

The widespread use of titanium dioxide nanoparticles (TiO2-NP) in consumer products is the cause of its appearance in wastewater and effluents, reaching the aquatic environment. The evaluation of the biological impact of TiO2-NP and the need to understand its ecotoxicological impact to the aquatic ecosystem are of major concern. Bivalve mollusks may represent a target group for nanoparticle toxicity. Limnoperna fortunei (golden mussel), a freshwater bivalve organism that has been employed in biomonitoring environmental conditions. Comet assay, micronucleus test and oxidative damage to lipids and proteins were performed after the golden mussel was exposed to TiO2-NP (1, 5, 10 and 50 μg mL−1). The results demonstrate that TiO2-NP can damage the DNA of haemocytes after 2 h of exposure and the genotoxic activity significantly increased after 4 h exposure to TiO2-NP, at all the TiO2-NP concentrations. TiO2-NP was ineffective in causing mutagenicity in the haemolymph cells of golden mussel. The increase in the lipid peroxidation levels and carbonyl proteins after the exposure to TiO2-NP indicates the induction of oxidative stress at 2 h exposure with similar results to all TiO2-NP concentrations, but these effects did not occur at 4 h exposure. These results demonstrated that, although TiO2-NP is not mutagenic to golden mussel, it does induce DNA damage and oxidative stress in these organisms.

Garcinia mangostana,popularly known as “mangosteen fruit,” originates from Southeast Asia and came to Brazil about 80 years ago where it mainly grows in the states of Pará and Bahia. Although mangosteen or its extracts have been used for ages in Asian folk medicine, data on its potential genotoxicity is missing. We, therefore, evaluated genotoxicity/mutagenicity of hydroethanolic mangosteen extract [HEGM, 10 to 640 μg/mL] in established test assays (Comet assay, micronucleus test, andSalmonella/microsome test). In the Comet assay, HEGM-exposed human leukocytes showed no DNA damage. No significant HEGM-induced mutation in TA98 and TA100 strains ofSalmonella typhimurium(with or without metabolic activation) was observed and HEGM-exposed human lymphocytes had no increase of micronuclei. However, HEGM suggested exposure concentration-dependent antigenotoxic potential in leukocytes and antioxidant potential in the yeastSaccharomyces cerevisiae. HEGM preloading effectively protected against H2O2-induced DNA damage in leukocytes (Comet assay). Preloading of yeast with HEGM for up to 4 h significantly protected the cells from lethality of chronic H2O2-exposure, as expressed in better survival. Absence of genotoxicity and demonstration of an antigenotoxic and antioxidant potential suggest that HEGM or some substances contained in it may hold promise for pharmaceutical or nutraceutical application.

International audience; Epstein-Barr virus (EBV) is a widely distributed gamma-herpesvirus that has been associated with various cancers mainly from lymphocytic and epithelial origin. Although EBV-mediated oncogenesis has been associated with viral oncogenes expressed during latency, a growing set of evidence suggested that antiviral treatments directed against EBV lytic phase may contribute to prevent some forms of cancers, including EBV-positive Post-Transplant Lymphoproliferative Diseases. It is shown here that dipyridamole (DIP), a safe drug with favorable and broad pharmacological properties, inhibits EBV reactivation from B-cell lines. DIP repressed immediate early and early genes expression mostly through its ability to inhibit nucleoside uptake. Considering its wide clinical use, DIP repurposing could shortly be evaluated, alone or in combination with other antivirals, to treat EBV-related diseases where lytic replication plays a deleterious role.

Cumulative evidence from research studies has shown that the shiitake culinary-medicinal mushroom, Lentinus edodes, is an excellent source of natural antitumor agents and is capable of inhibiting cancer cell growth. However, the cell signaling pathway that leads tumor cells to apoptosis is not well understood because many chemical compounds may be acting. This study investigated the chemopreventive effects of an L. edodes aqueous extract on human HEp-2 epithelial larynx carcinoma cells and normal human MRC-5 lung fibroblasts by identifying proliferative and apoptotic pathways. The chemical characterization of the dry powder was assessed by high-performance liquid chromatography. Antiproliferative and proapoptotic effects induced by the extract were evaluated by assessing proliferative markers, cell sorting through flow cytometry, and expression levels of apoptotic proteins with Western blotting. The results suggest that inhibition of cell proliferation was more prominent in HEp-2 than in MRC-5 cells. Cell death analysis showed the appearance of cell populations in the sub-G1 phase, with late apoptotic signal increased in a dose-dependent manner. In addition, the aqueous extract induced depolarization of mitochondria, activating the generation of intracellular reactive oxygen species in HEp-2 cells. These observations suggest that L. edodes extract may exert a chemopreventive effect, regulating mitotic induction of apoptogenic signals. These findings highlight the mushroom's pharmacological potential in cancer treatment.

Biomaterials can be applied in tissue engineering as scaffolds that resemble the extracellular matrix functioning as a temporary structure for cell proliferation and reconstruction of new organs and tissues. To evaluate the potential use of scaffolds as a biomaterial, this work proposes the development and characterization of polyurethane (PU), poly(D,L-lactic acid) (PDLLA) and polyurethane/poly( d , l -lactic acid) (PU/PDLLA) scaffolds produced by gas foaming technique. The neat polymers and the blends were characterized, in film form, by gel permeation chromatography (GPC), thermogravimetry (TG), differential scanning calorimetry (DSC) and field emission gun scanning electron microscopy (FEG-SEM). After supercritical fluid technology, in scaffolds form, the samples were characterized by FEG-SEM, pore size, density, cytotoxicity and cell adhesion. For film characterization the PU/PDLLA sample presented intermediate characteristics compared to the neat polymers, exhibiting the behavior of both polymers in the sample without phase separation in the FEG-SEM micrograph and bimodal molar weight distribution by GPC. The scaffolds showed interconnectivity and pore size of 141 μm ± 108 μm for PUsc and 52 μm ± 32 μm for PDLLAsc. The PU/PDLLAsc exhibited a bimodal structure in which the PU in the mixture revealed pores of 75 μm ± 57 μm, while for PDLLA, the pore size was 19 μm ± 12 μm. In vitro tests confirmed the adhesion of L929 cells to PUsc, PDLLAsc and PU/PDLLAsc, showing no cytotoxic effect. Finally, it can be concluded that it is possible to produce PU, PDLLA and PU/PDLLA scaffolds by supercritical fluid, which may be applied as biomaterials.

Made available in DSpace on 2018-11-26T17:52:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-09-01 COLCIENCIAS/Colombia Universidad del Sinu/Colombia (UNISINU) Universidad del Cauca/Colombia (UNICAUCA) Universidad Luterana do Brasil (ULBRA) Universidade Federal do Rio Grande do Sul/Brasil (UFRGS) During coal surface mining, several activities such as drilling, blasting, loading, and transport produce large quantities of particulate matter (PM) that is directly emitted into the atmosphere. Occupational exposure to this PM has been associated with an increase of DNA damage, but there is a scarcity of data examining the impact of these industrial operations in cytogenetic endpoints frequency and cancer risk of potentially exposed surrounding populations. In this study, we used a Geographic Information Systems (GIS) approach and Inverse Distance Weighting (IDW) methods to perform a spatial and statistical analysis to explore whether exposure to PM2.5 and PM10 pollution, and additional factors, including the enrichment of the PM with inorganic elements, contribute to cytogenetic damage in residents living in proximity to an open-pit coal mining area. Results showed a spatial relationship between exposure to elevated concentrations of PM2.5, PK10 and micronuclei frequency in binucleated (MNBN) and mono nucleated (MNMONO) cells. Active pits, disposal, and storage areas could be identified as the possible emission sources of combustion elements. Mining activities were also correlated with increased concentrations of highly enriched elements like S, Cu and Cr in the atmosphere, corroborating its role in the inorganic elements pollution around coal mines. Elements enriched in the PM2.5 fraction contributed to increasing of MNBN but seems to be more related to increased MNMONO frequencies and DNA damage accumulated in vivo. The combined use of GIS and IDW methods could represent an important tool for monitoring potential cancer risk associated to dynamically distributed variables like the PM. (C) 2018 Elsevier Ltd. All rights reserved. Univ Sinu, Lab Invest Biomed & Biol Mol, Fac Ciencias Salud, Calle 38 Cra 1 W,Barrio Juan XXIII, Cordoba, Colombia Univ Fed Rio Grande do Sul, Inst Biociencias, Dept Biofis, Porto Alegre, RS, Brazil Univ Estadual Paulista Julio de Mezquita Filho, IPPRI, Praca S,108-3 Andar, Sao Paulo, Brazil Univ Cordoba, Dept Geog & Medio Ambiente, Cordoba, Colombia Univ Sao Paulo, Inst Matemat & Estat, Sao Paulo, Brazil Univ Luterana Brasil, ULBRA, Lab Genet Toxicol, Canoas, RS, Brazil Univ Estadual Paulista Julio de Mezquita Filho, IPPRI, Praca S,108-3 Andar, Sao Paulo, Brazil COLCIENCIAS/Colombia: 128356934353/2013 Universidade Federal do Rio Grande do Sul/Brasil (UFRGS): 751/2013

Doxorubicin (DOX) and Mitoxantrone (MTX) are very effective drugs for a range of tumors despite being highly cardiotoxic. DNA topoisomerase 2 beta (Top2s) was revealed as key mediator of DOX-induced cardiotoxicity, although ROS generation is also an important mechanism. Oxidative stress is also an important issue in MTX-induced cardiotoxicity that is manifested by mitochondrial dysfunction. Studies have demonstrated the relationship between PARP-1 overactivation and cell viability in DOX-treated cardiomyocytes. In reference of MTX, data regarding PARP-1 overactivation as the mechanism responsible for cardiotoxicity is difficult to find. The aim of this study was to evaluate the influence of PARP-1 inhibitor DPQ on DOX- and MTX-mediated cardiotoxicity. Cells were exposed for 24 h to DOX or MTX in the presence or absence of DPQ. Viability, apoptosis, and genotoxicity assays were carried out. Immunofluorescence of phosphorylated histone H2AX was analyzed in H9c2 cells and cardiomyocytes from neonatal rats. Results demonstrated that DPQ co-treatment increases DOX-induced apoptosis in H9c2 cells. DPQ also prevents DOX and MTX-ROS generation in part by increasing SOD and CAT activities. Furthermore, DPQ co-treatment increased the generation of DNA strand breaks by DOX and MTX whilst also inducing phosphorylation of H2AX, MRE11, and ATM in H9c2 cells. Our results demonstrated that as well as increasing DNA damage and inducing apoptotic cell death, DPQ enhances DOX- and MTX-mediated cytotoxicity in H9c2.

This paper reports the DNA interaction and cytotoxicity of binary and ternary copper(II) complexes of valproic acid with phenanthroline or bipyridine and the complementary characterization of Cu(Valp)2Bipy by crystallography. Circular dichroism, plasmid and oligonucleotide assays have shown that the complexes interact with DNA in different manners and are able to cleave plasmid DNA and oligonucleotides at concentrations from 10 to 1000 mol L-1. The plasmid DNA cleavage is enhanced 650, 375 and 285 times by photo activation with UVB light for the complexes Cu(Valp)2Phen, Cu(Valp)2Bipy and Cu2(Valp)4, respectively. Cytotoxicity assays demonstrated that V79 cells were more sensitive to CuII derivatives than sodium valproate as evaluated by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) and clonogenic assays, where the cytotoxic profile of the compounds was: Cu(Valp)2Phen higher than Cu(Valp)2Bipy, higher than Cu2(Valp)4. Therefore, we report two copper complexes, which interact with DNA and promote its cleavage, leading to an enhanced cytotoxicity when compared to valproic acid.

Repair of DNA-targeted anticancer agents is an active area of investigation of both fundamental and clinical interest. However, most studies have focused on a small number of compounds limiting our understanding of both DNA repair and the DNA damage response. S23906 is an acronycine derivative that shows strong activity toward solid tumors in experimental models. S23906 forms bulky monofunctional DNA adducts in the minor groove which leads to destabilization of the double-stranded helix. We now report that S23906 induces formation of DNA double strand breaks that are processed through homologous recombination (HR) but not Non-Homologous End-Joining (NHEJ) repair. Interestingly, S23906 exposure was accompanied by a higher sensitivity of BRCA2-deficient cells compared to other HR deficient cell lines and by an S-phase accumulation in wild-type (wt), but not in BRCA2-deficient cells. Recently, we have shown that S23906-induced S phase arrest was mediated by the checkpoint kinase Chk1. However, its activated phosphorylated form is equally induced by S23906 in wt and BRCA2-deficient cells, likely indicating a role for BRCA2 downstream of Chk1. Accordingly, override of the S phase arrest by either 7-hydroxystaurosporine (UCN-01) or AZD7762 potentiates the cytotoxic activity of S23906 in wt, but not in BRCA2-deficient cells. Together, our findings suggest that the pronounced sensitivity of BRCA2-deficient cells to S23906 is due to both a defective S-phase arrest and the absence of HR repair. Tumors with deficiencies for proteins involved in HR, and BRCA2 in particular, may thus show increased sensitivity to S23906, thereby providing a rationale for patient selection in clinical trials.

The present study evaluates antigenotoxic and antimutagenic properties of diphenyl ditelluride (DPDT) against several known mutagens in Chinese hamster lung fibroblasts (V79 cells). DPDT was not cytotoxic and genotoxic at concentrations ranging from 0.01 to 0.1 μM. The pre-treatment for 2h with this organotellurium compound at non-cytotoxic dose range (0.01, 0.05 and 0.1 μM) increased cell survival after challenge with hydrogen peroxide (H2O2), t-butyl hydroperoxide (t-BOOH), methylmethanesulphonate (MMS) or ultraviolet (UV)C radiation. In addition, the pre-treatment with DPDT decreased the DNA damage and Formamidopyrimidine DNA-glycosylase (Fpg)- and Endonuclease III (Endo III) sensitive sites induction by the studied genotoxic agents, as verified by comet assay and modified comet assay, respectively. The pre-treatment also reduced micronucleus frequency, revealing the protector effect of DPDT against MMS and UVC-induced mutagenesis. Our results demonstrate that DPDT-treated cells at concentration range of 0.01-0.1 μM do not change thiobarbituric acid reactive species (TBARS) levels and ROS generation. Moreover, DPDT pre-treatment at this concentration range decreases the ROS induction by H2O2 and t-BOOH treatment indicating antioxidant potential. On the other hand, concentrations higher than 0.1 μM increase TBARS formation and inhibited superoxide dismutase (SOD) activity, suggesting pro-oxidative effect of this compound at high concentrations. Our results suggest that DPDT presents antigenotoxic and antimutagenic properties at concentration range of 0.01-0.1 μM. The protection effect could be attributed to antioxidant capacity of DPDT at this concentration range in V79 cells.

The aim of this study was to explore the effects of selenium (Se) on locomotor activity and DNA damage in a rat model of Parkinson's disease (PD) induced by paraquat (PQ).Forty-eight male Wistar rats were divided into four groups: control group (n = 12), Se group (n = 12), PQ group (n = 12), and Se + PQ group (n = 12). PQ was administered intraperitoneally (10 mg/kg). Se was offered in the drinking water at a concentration of 11.18 μg/L. Locomotor activity was evaluated weekly using the narrow beam test. The comet assay was performed to assess the level of DNA damage in leukocytes and in brain cells.As expected, increased DNA damage was found in the PQ group compared with the control and Se groups (P 0.001). Interestingly, coadministration of Se and PQ effectively prevented the harmful effects of the toxin in locomotor activity and at the molecular level, reducing bradykinesia (P 0.01) and DNA damage in leukocytes compared with the PQ-only group (P 0.001), whereas the levels of DNA damage were comparable to those found in the control and Se groups (P 0.05). Using the comet assay to analyze brain cells, no differences were found between the groups with regard to damage index (P = 0.774), damage frequency (P = 0.817), or non-detectable cell nuclei (P = 0.481).In this experimental model of PQ-induced PD, the use of Se could contribute to the maintenance of locomotor activity and the integrity of leukocytes DNA. No changes in the levels of DNA damage in brain cells were observed between the experimental groups.

MutY is a glycosylase known for its role in DNA base excision repair (BER). It is critically important in the prevention of DNA mutations derived from 7,8-dihydro-8-oxoguanine (8-oxoG), which are the major lesions resulting from guanine oxidation. MutY has been described as a DNA repair enzyme in the GO system responsible for removing adenine residues misincorporated in 8-oxoG:A mispairs, avoiding G:C to T:A mutations. Further studies have shown that this enzyme binds to other mispairs, interacts with several enzymes, avoids different transversions/transitions in DNA, and is involved in different repair pathways. Additional activities have been reported for MutY, such as the repair of replication errors in newly synthesized DNA strands through its glycosylase activity. Moreover, MutY is a highly conserved enzyme present in several prokaryotic and eukaryotic organisms. MutY defects are associated with a hereditary colorectal cancer syndrome termed MUTYH-associated polyposis (MAP). Here, we have reviewed the roles of MutY in the repair of mispaired bases in DNA as well as its activities beyond the GO system.

DNA and chromosomal damage in individuals occupationally exposed to coal mining residues have repeatedly been reported in lymphocytes and epithelial cells, suggesting a systemic exposure-response in which generation of oxidative damage may play a major role. Nevertheless, the understanding of this mechanism is still incomplete, particularly in regard to environmental exposures. This study aimed to evaluate DNA damage using the cytome assay (BMN-cyt) in buccal cells and its relation to primary and oxidative DNA damage in lymphocytes, assessed by the high-throughput alkaline and modified (FPG-ENDO III) Comet assay in individuals with environmental exposure to coal mining residues in northern Colombia. Considering metals from coal mining activities as the main source of reactive oxygen species (ROS) generation, the concentrations of inorganic elements in blood samples was also assessed. The analysis revealed that frequencies of BMN-cyt parameters related to DNA damage (micronuclei), cytokinesis (binucleated cells) and cell death (condensed chromatin, karyorrhexis, pyknosis and karyolysis) were significantly higher in individuals that were environmentally exposed to coal compared to the unexposed group. The level of % Tail DNA in the alkaline and the modified Comet assay was 4.0 and 4.3 times higher among exposed individuals than in unexposed controls respectively. Increased MN frequencies in buccal cells were correlated with increased %Tail DNA in alkaline and FPG Comet assay. Additionally, exposed individuals had higher concentrations of Cr, Ni, Mn, and Br in the blood compared to unexposed controls. %Tail DNA in alkaline Comet assay was highly correlated with Al, Mn, and Br concentrations, while %Tail DNA in the FPG Comet assay correlated with Mn levels. These results suggest that oxidative damage, particularly purine oxidation, may play an essential role in DNA damage in individuals exposed to coal residues and that some inorganic elements are related to this effect.

Continuous increases in the rates of tumor diseases have highlighted the need for identification of novel and inexpensive antitumor agents from natural sources. In this study, we investigated the effects of enriched fraction from hydroalcoholic Brazilian red propolis extract against Hep-2 cancer cell line. Initially 201 fractions were arranged in 12 groups according to their chromatographic characteristics (A-L). After an in vitro cell viability screening, J and L were further selected as promising enriched fractions for this study. The chemical characterization was performed and Biochanin A, Formononetin, and Liquiritigenin compounds were quantified. Through MTT viability assay and morphological changes observed by Giemsa and DAPI staining, the results showed that red propolis inhibited cancer cells growth. Flow cytometry results indicated effects that were partly mediated through programmed cell death as confirmed by externalization of phosphatidylserine, DNA cleaved assay, increase at SUB G1-G0 phase in cell cycle analysis and loss of mitochondrial membrane potential. In conclusion, our results demonstrated that red propolis enriched fractions promoted apoptotic effects in human cancer cells through the mechanisms involving mitochondrial perturbation. Therefore, red propolis fractions contain candidate agents for adjuvant cancer treatment, which further studies should elucidate the comprehensive mechanistic pathways.

Mutations in cancer cells frequently result in cell cycle alterations that lead to unrestricted growth compared to normal cells. Considering this phenomenon, many drugs have been developed to inhibit different cell-cycle phases. Mitotic phase targeting disturbs mitosis in tumor cells, triggers the spindle assembly checkpoint and frequently results in cell death. The first anti-mitotics to enter clinical trials aimed to target tubulin. Although these drugs improved the treatment of certain cancers, and many anti-microtubule compounds are already approved for clinical use, severe adverse events such as neuropathies were observed. Since then, efforts have been focused on the development of drugs that also target kinases, motor proteins and multi-protein complexes involved in mitosis. In this review, we summarize the major proteins involved in the mitotic phase that can also be targeted for cancer treatment. Finally, we address the activity of anti-mitotic drugs tested in clinical trials in recent years.

The diphenyl ditelluride (DPDT) is a prototype for the development of new biologically active molecules. In previous studies, DPDT showed an elevated cytotoxicity in Chinese hamster fibroblast (V79) cells but the mechanisms for reduction of cell viability still remain unknown. DPDT showed mutagenic properties by induction of frameshift mutations in bacterium Salmonella typhimurium and yeast Saccharomyces cerevisiae. This organotelluride also induced DNA strand breaks in V79 cells. In this work, we investigated the mechanism of DPDT cytotoxicity by evaluating the effects of this compound on cell cycle progression, apoptosis induction and topoisomerase I inhibition. Significant decrease of V79 cell viability after DPDT treatment was revealed by MTT assay. Morphological analysis showed induction of apoptosis and necrosis by DPDT in V79 cells. An increase of caspase 3/7 activity confirmed apoptosis induction. The cell cycle analysis showed an increase in the percentage of V79 cells in S phase and sub-G1 phase. The yeast strain deficient in topoisomerase I (Topo I) showed higher tolerance to DPDT compared with the isogenic wild-type strain, suggesting that the interaction with this enzyme could be involved in DPDT toxicity. The sensitivity to DPDT found in top3∆ strain indicates that yeast topoisomerase 3 (Top3p) could participate in the repair of DNA lesions induced by the DPDT. We also demonstrated that DPDT inhibits human DNA topoisomerase I (Topo I) activity by DNA relaxation assay. Therefore, our results suggest that the DPDT-induced cell cycle arrest and reduction in cell viability could be attributed to interaction with topoisomerase I enzyme.