Antimicrobial Activity of Essential-Oil-Based Nanostructured Lipid Carriers against Campylobacter Spp. Isolated from Chicken Carcasses.

Campylobacter is a virulent Gram-negative bacterial genus mainly found in the intestines of poultry. The indiscriminate use of traditional antibiotics has led to drug resistance in these pathogens, necessitating the development of more efficient and less toxic therapies. Despite their complex biologically active structures, the clinical applications of essential oils (EOs) remain limited. Therefore, this study aimed to increase the bioavailability, stability, and biocompatibility and decrease the photodegradation and toxicity of EO using nanotechnology. The diffusion disk test revealed the potent anti-Campylobacter activity of cinnamon, lemongrass, clove, geranium, and oregano EOs (>50 mm). These were subsequently used to prepare nanostructured lipid carriers (NLCs). Formulations containing these EOs inhibited Campylobacter spp. growth at low concentrations (0.2 mg/mL). The particle size, polydispersity index, and zeta potential of these systems were monitored, confirming its physicochemical stability for 210 days at 25 °C. FTIR-ATR and DSC analyses confirmed excellent miscibility among the excipients, and FE-SEM elucidated a spherical shape with well-delimited contours of nanoparticles. The best NLCs were tested regarding nanotoxicity in a chicken embryo model. These results indicate that the NLC-based geranium EO is the most promising and safe system for the control and treatment of multidrug-resistant strains of Campylobacter spp.

The impact of biomolecule interactions on the cytotoxic effects of rhenium(I) tricarbonyl complexes.

Rhenium complexes show great promise as anticancer drug candidates. Specifically, compounds with a Re(CO)3(NN)(py)+ core in their architecture have shown cytotoxicity equal to or greater than that of well-established anticancer drugs based on platinum or organic molecules. This study aimed to evaluate how the strength of the interaction between rhenium(I) tricarbonyl complexes fac-[Re(CO)3(NN)(py)]+, NN = 1,10-phenanthroline (phen), dipyrido[3,2-f:2',3'-h]quinoxaline (dpq) or dipyrido[3,2-a:2'3'-c]phenazine (dppz) and biomolecules (protein, lipid and DNA) impacted the corresponding cytotoxic effect in cells. Results showed that fac-[Re(CO)3(dppz)(py)]+ has higher Log Po/w and binding constant (Kb) with biomolecules (protein, lipid and DNA) compared to complexes of fac-[Re(CO)3(phen)(py)]+ and fac-[Re(CO)3(dpq)(py)]+. As consequence, fac-[Re(CO)3(dppz)(py)]+ exhibited the highest cytotoxicity (IC50 = 8.5 µM for HeLa cells) for fac-[Re(CO)3(dppz)(py)]+ among the studied compounds (IC50 > 15 µM). This highest cytotoxicity of fac-[Re(CO)3(dppz)(py)]+ are probably related to its lipophilicity, higher permeation of the lipid bilayers of cells, and a more potent interaction of the dppz ligand with biomolecules (protein and DNA). Our findings open novel avenues for rational drug design and highlight the importance of considering the chemical structures of rhenium complexes that strongly interact with biomolecules (proteins, lipids, and DNA).

Mutagenicity, hepatotoxicity, and neurotoxicity of glyphosate and fipronil commercial formulations in Amazon turtles neonates (Podocnemis expansa).

Pesticides are considered one of the main causes of the population decline of reptiles worldwide, with freshwater turtles being particularly susceptible to aquatic contamination. In this context, we investigated the potential mutagenic, hepatotoxic, and neurotoxic effects in neonates of Podocnemis expansa exposed to substrate contaminated with different concentrations of glyphosate and/or fipronil during embryonic development. Eggs collected from the natural environment were artificially incubated in sand moistened with pure water, water added with glyphosate Atar 48® at concentrations of 65 and 6500 µg/L (groups G1 and G2, respectively), water added with fipronil Regent® 800WG at 4 and 400 µg/L (groups F1 and F2, respectively) and, water added with the combination of 65 µg/L glyphosate and 4 µg/L fipronil or with 6500 µg/L glyphosate and 400 µg/L fipronil (groups GF1 and GF2, respectively). For mutagenicity analysis, we evaluated the frequency of micronuclei (MN) and other erythrocyte nuclear abnormalities (ENAs), while for evaluation of hepatotoxicity and neurotoxicity, livers and encephalon were analyzed for histopathological alterations. Exposure to pesticides, alone or in combination, increased the frequency of erythrocyte nuclear abnormalities, particularly blebbed nuclei, moved nuclei, and notched nuclei. Individuals exposed to fipronil exhibited congestion and inflammatory infiltrate in their liver tissue, while, in the encephalon, congestion, and necrosis were present. Our study confirms that the incubation of eggs in substrate polluted with glyphosate and fipronil causes histopathological damage and mutagenic alteration in P. expansa, highlighting the importance of using different biomarkers to evaluate the ecotoxicological effects of these pesticides, especially in oviparous animals.

Copper(II) Complex Containing 4-Fluorophenoxyacetic Acid Hydrazide and 1,10-Phenanthroline: A Prostate Cancer Cell-Selective and Low-Toxic Copper(II) Compound.

Prostate Cancer (PCa) is the second leading cause of cancer-related deaths among men worldwide. The treatment of advanced cases is based on chemotherapy, which lacks specificity and efficacy, due to severe side effects and resistance to the traditional drugs. Copper complexes have shown antitumoral efficacy and low toxicity, being considered a promising class of metal-based drugs for the treatment of malignant neoplasms. Thus, the present study aimed to evaluate the cellular effects of a copper(II) complex with 4-fluorophenoxyacetic acid hydrazide and 1,10-phenanthroline (1) on PCa cell lines, as well as the mutagenic/recombinogenic and anticarcinogenic potential of 1 in Drosophila melanogaster. PNT-2 (non-tumorigenic), LNCaP (hormone-responsive PCa) and PC-3 (androgen-independent PCa) cells were cultured, and cytotoxicity was assessed using the MTT assay. The expression levels of the proliferation markers Ki-67 and Cyclin D1 were analyzed by flow cytometry. Furthermore, the Somatic Mutation and Recombination Test (SMART) and the Epithelial Tumor Test (ETT) were performed. Complex 1 was selective to LNCaP cells, significantly reducing Ki-67 and Cyclin D1 expression levels. Sub-toxic concentrations of complex 1 were defined by the toxicity test in D. melanogaster, and no mutagenic/recombinogenic/carcinogenic effects were observed. Anticarcinogenic potential was observed in D. melanogaster, suggesting modulating activity of the complex 1 against Doxorubicin, a drug used as control by its carcinogenic properties. Therefore, complex 1 is a possible starting point for the development of new antitumor agents for the treatment of PCa.

In vitro cytotoxic and genotoxic analysis of Garcinia humilis crude extract

Garcinia humilis, known commonly as achachairú or bacupari, has great medicinal value. Their fruits have pharmacological, antibacterial, antioxidant, and anticancer properties. Therefore, the objective of the present study was to evaluate the cytotoxicity and genotoxicity of G. humilis crude extract in breast tumor cells. Cytotoxicity was determined using the Resazurin reduction assay and genotoxicity by the single cell gel electrophoresis assay (Comet assay) on human MCF-7 cells. Crude extract of G. humilis was cytotoxic only when used at high concentrations (IC50 = 5.084 mg mL-1). The Comet assay showed that the crude extract did not induce genotoxicity at 1 and 5 mg mL-1 but did show signs of DNA fragmentation and DNA fragmentation at 10 mg mL-1. The cytotoxic activity against breast adenocarcinoma cells at high concentrations suggests that this medicinal plant could be used with caution and must be further studied to understand better its therapeutic and toxicological potential in the human body.

A selective CuII complex with 4-fluorophenoxyacetic acid hydrazide and phenanthroline displays DNA-cleaving and pro-apoptotic properties in cancer cells.

The thin line between efficacy and toxicity has challenged cancer therapy. As copper is an essential micronutrient and is important to tumor biology, CuII complexes emerged as an alternative to chemotherapy; however, its biological properties need to be better understood. Thus, we report in vitro the antitumor effects of two CuII complexes named [Cu(4-fh)(phen)(ClO4)2] (complex 1) and [Cu(4-nh)(phen)(ClO4)2]·H2O (complex 2), in which 4-fh = 4-fluorophenoxyacetic acid hydrazide; 4-nh = 4-nitrobenzoic hydrazide and phen = 1,10-phenanthroline. Both complexes presented cytotoxic activity against tumor cells, but only complex 1 showed significant selectivity. Complex 1 also induced DNA-damage, led to G0/G1 arrest and triggered apoptosis, which was initiated by an autophagy dysfunction. The significant in vitro selectivity and the action mechanism of complex 1 are noteworthy and reveal this prodrug as promising for anticancer therapy.

Ovarian tissue features assessed in bovine fetuses after vitrification and xenotransplantation procedures.

Cryopreservation and transplantation of ovarian tissue are proposed methods for the restoration of endocrine function and reproductive potential. Therefore, this study aimed to evaluate the effects of vitrification and xenotransplantation on follicle viability, activation, stromal cell integrity, vascularization, and micronuclei formation. Bovine fetal ovaries were fragmented and assigned to the following groups: Fresh control (FC), ovarian fragments immediately fixed; Vitrified control (VC), ovarian fragments vitrified; Vitrified xenotransplanted (VX), ovarian fragments vitrified and xenotransplanted; and Fresh xenotransplanted (FX), ovarian fragments xenotransplanted. Ovarian fragments were grafted in female BALB/c mice and recovered after 14 days. Follicular viability was preserved (P > 0.05) in VC group. The rate of developing follicles was greater (P < 0.05) in the FX group compared to other groups. Follicular density was higher (P < 0.05) in the VC group than the FC, VX, and FX groups. A decrease (P < 0.05) of stromal cell density was recorded after vitrification (VC vs. FX). Blood vessel density decreased in VC, VX, and FX groups compared with the FC group, and blood vessel density was correlated with follicular viability (positively; P = 0.07) and developing follicles (negatively; P < 0.001). Both vitrification and xenotransplantation groups (VC, VX, and FX) had a greater (P < 0.05) number of cells with one MN compared to the FC group. In summary, our findings showed that both vitrification and xenotransplantation modified blood vessel, follicular and stromal cell densities, follicular viability and activation, and micronuclei formation in ovarian tissue.

Cytogenotoxic effects of nitrogen on hydroponic lettuce / Efeitos citogenotóxicos do nitrogênio em alface hidropônica

Nitrogen accumulation in hydroponically-grown lettuce may pose a health risk to consumers. Thus, the objective of this study was to analyze different concentrations of nitrogen applications in hydroponic lettuce cultivation and their effect on toxicity, cytotoxicity and genotoxicity. A nutrient film technique (NFT) hydroponic system was used to grow the lettuce variety "Vanda." The treatments consisted of different concentrations of nitrogen (in the form of calcium nitrate) in Furlani solution (75, 100, 125 and 150%), a negative and a positive control. The following commercial characteristics were measured: plant fresh weight (PFW), root fresh weight (RFW), shoot fresh weight (SFW), shoot diameter (SD), root dry weight (RDW), shoot dry weight (SDW) and leaf nitrogen (LN). Cytogenotoxicity was indicated by toxicity, cytotoxicity and genotoxicity, which were in turn determined by root length, the mitotic index, chromosomal aberrations and the presence of micronuclei. The nitrogen concentrations used in this experiment did not cause phenotypic toxicity or cytotoxicity in lettuce roots. The most severe genotoxicity was observed at the 125% nitrogen concentration, which nevertheless did not affect commercial characteristics. Although nitrogen fertilization provides great benefits to agriculture, such as greater yields, indiscriminate use should be avoided since concentrations above recommended rates may induce genotoxicity.

O acúmulo de nitrogênio em alface cultivada hidroponicamente pode representar um risco à saúde dos consumidores. Assim, o objetivo deste estudo foi analisar diferentes concentrações de aplicações de nitrogênio no cultivo de alface hidropônica e seus efeitos na toxicidade, citotoxicidade e genotoxicidade. Em sistema hidropônico do tipo filme de nutrientes (NFT) foi usado para cultivar a variedade de alface "Vanda". Os tratamentos consistiram em diferentes concentrações de nitrogênio (na forma de nitrato de cálcio) na solução Furlani (75, 100, 125 e 150%), um controle negativo e um positivo. Foram medidas as seguintes características comerciais: peso fresco da planta (PFW), peso fresco da raiz (RFW), peso fresco da parte aérea (SFW), diâmetro da parte aérea (SD), peso seco da raiz (RDW), peso seco da parte aérea (SDW) e nitrogênio foliar (LN). A citogenotoxicidade foi indicada por toxicidade, citotoxicidade e genotoxicidade, que por sua vez foram determinadas pelo comprimento da raiz, índice mitótico, aberrações cromossômicas e presença de micronúcleos. As concentrações de nitrogênio utilizadas neste experimento não causaram toxicidade fenotípica ou citotoxicidade em raízes de alface. A genotoxicidade mais severa foi observada na concentração de nitrogênio de 125%, que, no entanto, não afetou as características comerciais. Embora a fertilização nitrogenada traga grandes benefícios à agricultura, como maiores rendimentos, o uso indiscriminado deve ser evitado, pois concentrações acima das taxas recomendadas podem induzir genotoxicidade.

Using native and invasive livebearing fishes (Poeciliidae, Teleostei) for the integrated biological assessment of pollution in urban streams.

Invasive species are increasingly replacing native species, especially in anthropogenically transformed or polluted habitats. This opens the possibility to use invasive species as indicator taxa for the biological assessment of pollution. Integrated biological assessment, however, additionally relies on the application of multiple approaches to quantify physiological or cytogenetic responses to pollution within the same focal species. This is challenging when species are restricted to either polluted or unpolluted sites. Here, we make use of a small group of neotropical livebearing fishes (family Poeciliidae) for the integrated biological assessment of water quality. Comparing urban and suburban stream sections that receive varying degrees of pollution from industrial and domestic waste waters in and around the Brazilian city of Uberlândia, we demonstrate that two members of this family may indeed serve as indicators of water pollution levels. The native species Phalloceros caudimaculatus appears to be replaced by invasive guppies (Poecilia reticulata) at heavily polluted sites. Nevertheless, we demonstrate that both species could be used for the assessment of bioaccumulation of heavy metals (Pb, Cu, and Cr). Ambient (sediment) concentrations predicted concentrations in somatic tissue across species (R2-values between 0.74 and 0.96). Moreover, we used cytogenetic methods to provide an estimate of genotoxic effects of water pollution and found pollution levels (multiple variables, condensed into principal components) to predict the occurrence of nuclear abnormalities (e.g., frequencies of micro-nucleated cells) across species (R2 between 0.69 and 0.83). The occurrence of poeciliid fishes in urban and polluted environments renders this family a prime group of focal organisms for biological water quality monitoring and assessment. Both species could be used interchangeably to assess genotoxic effects of water pollution, which may facilitate future comparative analyses over extensive geographic scales, as members of the family Poeciliidae have become invasive in tropical and subtropical regions worldwide.

Genotoxicity assessment of polluted urban streams using a native fish Astyanax altiparanae.

Water quality has declined globally due to increased contamination of aquatic ecosystems. The use of fish genotoxicity biomarkers may improve and complement parameters for environmental risk assessment. The aim of this study was to assess the genotoxicity of samples collected from streams of the Jordão River, a tributary of the Paranaíba River, Brazil with different levels of metal contamination, utilizing a native fish species to determine the sensitivity and viability of implementing a useful, reliable technique for routine biomonitoring programs. Chemical analysis of water and sediments collected from different sites indicated that a gradient of contamination existed as evidenced by different concentrations of metals detected. After chronic exposure to contaminated samples, micronucleus (MN) frequencies in fish erythrocytes were measured and correlation with environmental parameters determined. Sites where the water concentrations of the metals aluminum (Al), iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu) were high indicating a greater genotoxic potential of these elements. At the samples collected from the urban zone, a gradual increase was found for chromium (Cr), cadmium (Cd) and nickel (Ni) indicative of adverse impacts of discharge of urban effluents. Data demonstrated that Astyanax altiparanae, used in the test, exhibited a reliable sensitivity for detection of genotoxic consequences attributed to exposure to water samples collected near the discharge of industrial and domestic waste.

Action of copper(II) complex with ß-diketone and 1,10-phenanthroline (CBP-01) on sarcoma cells and biological effects under cell death.

This work reports the biological evaluation of a copper complex of the type [Cu(O-O)(N-N)ClO4], in which O-O = 4,4,4-trifluoro-1-phenyl-1,3-butanedione (Hbta) and N-N = 1,10-phenanthroline (phen), whose generic name is CBP-01. The cytotoxic effect of CBP-01 was evaluated by resazurin assay and cell proliferation was determined by MTT assay. DNA fragmentation was analyzed by gel electrophoresis. Cell cycle progression was detected through propidium iodide (PI) staining. Apoptosis and autophagy were determined by, respectively, Annexin V and 7-AAD staining and monodansylcadaverine (MDC) staining. The changes in intracellular reactive oxygen species levels were detected by DCFDA analysis. The copper complex CBP-01 showed in vitro antitumor activity with IC50s values of 7.4 µM against Sarcoma 180 and 26.4 against murine myoblast cells, displaying selectivity toward the tumor cell tested in vitro (SI > 3). An increase in reactive oxygen species (ROS) generation was observed, which may be related to the action mechanism of the complex. The complex CBP-01 may induce DNA damage leading cells to accumulate at G0/G1 checkpoint where, apparently, cells that are not able to recover from the damage are driven to cell death. Evidence has shown that cell death is initiated by autophagy dysfunction, culminating in apoptosis induction. The search for new metal-based drugs is focused on overcoming the drawbacks of already used agents such as acquired resistance and non-specificity; thus, the results obtained with CBP-01 show promising effects on cancer cells.

Action of copper(II) complex with ß-diketone and 1,10-phenanthroline (CBP-01) on sarcoma cells and biological effects under cell death

This work reports the biological evaluation of a copper complex of the type [Cu(O–O)(N–N)ClO4], in whichO–O = 4,4,4-trifluoro-1-phenyl-1,3-butanedione (Hbta) and N–N = 1,10-phenanthroline (phen), whose genericname is CBP-01. The cytotoxic effect of CBP-01 was evaluated by resazurin assay and cell proliferation wasdetermined by MTT assay. DNA fragmentation was analyzed by gel electrophoresis. Cell cycle progression wasdetected through propidium iodide (PI) staining. Apoptosis and autophagy were determined by, respectively,Annexin V and 7-AAD staining and monodansylcadaverine (MDC) staining. The changes in intracellular reactiveoxygen species levels were detected by DCFDA analysis. The copper complex CBP-01 showed in vitro antitumoractivity with IC50s values of 7.4µM against Sarcoma 180 and 26.4 against murine myoblast cells, displayingselectivity toward the tumor cell tested in vitro (SI > 3). An increase in reactive oxygen species (ROS) gen-eration was observed, which may be related to the action mechanism of the complex. The complex CBP-01 mayinduce DNA damage leading cells to accumulate at G0/G1 checkpoint where, apparently, cells that are not ableto recover from the damage are driven to cell death. Evidence has shown that cell death is initiated by autophagydysfunction, culminating in apoptosis induction. The search for new metal-based drugs is focused on overcomingthe drawbacks of already used agents such as acquired resistance and non-specificity; thus, the results obtainedwith CBP-01 show promising effects on cancer cells.

Action of copper(II) complex with ß-diketone and 1,10-phenanthroline (CBP-01) on sarcoma cells and biological effects under cell death

This work reports the biological evaluation of a copper complex of the type [Cu(O–O)(N–N)ClO4], in whichO–O = 4,4,4-trifluoro-1-phenyl-1,3-butanedione (Hbta) and N–N = 1,10-phenanthroline (phen), whose genericname is CBP-01. The cytotoxic effect of CBP-01 was evaluated by resazurin assay and cell proliferation wasdetermined by MTT assay. DNA fragmentation was analyzed by gel electrophoresis. Cell cycle progression wasdetected through propidium iodide (PI) staining. Apoptosis and autophagy were determined by, respectively,Annexin V and 7-AAD staining and monodansylcadaverine (MDC) staining. The changes in intracellular reactiveoxygen species levels were detected by DCFDA analysis. The copper complex CBP-01 showed in vitro antitumoractivity with IC50s values of 7.4µM against Sarcoma 180 and 26.4 against murine myoblast cells, displayingselectivity toward the tumor cell tested in vitro (SI > 3). An increase in reactive oxygen species (ROS) gen-eration was observed, which may be related to the action mechanism of the complex. The complex CBP-01 mayinduce DNA damage leading cells to accumulate at G0/G1 checkpoint where, apparently, cells that are not ableto recover from the damage are driven to cell death. Evidence has shown that cell death is initiated by autophagydysfunction, culminating in apoptosis induction. The search for new metal-based drugs is focused on overcomingthe drawbacks of already used agents such as acquired resistance and non-specificity; thus, the results obtainedwith CBP-01 show promising effects on cancer cells.

Genotoxic effects of BnSP-6, a Lys-49 phospholipase A2 (PLA2) homologue from Bothrops pauloensis snake venom, on MDA-MB-231 breast cancer cells.

Herein we evaluated the genotoxic effects of BnSP-6, a Lys-49 phospholipase A2 (PLA2) from Bothrops pauloensis, on breast cancer cells. BnSP-6 was able to induce a higher cytotoxic and genotoxic activity in MDA-MB-231 cells, when compared to MCF10A (a non-tumorigenic breast cell line), suggesting that this protein presented a possible preference for cancer cells. BnSP-6 inhibited MDA-MB-231 proliferation at 24, 48 and 72 h. In addition, BnSP-6 induced significant increase in the percentage of TUNEL-positive cells, a marker of DNA damage. To obtain novel insight into the direct DNA damage interference in MDA-MB-231 survival and proliferation, we evaluated cell cycle progression. BnSP-6 produced a significant decrease in 2N (G1) and an increase in the G2/M phase and this capacity is likely related to the modulation of expression of progression cell cycle-associated genes (CCND1, CCNE1, CDC25A, CHEK2, E2F1, CDH-1 and NF-kB). Taken together, these results indicate that BnSP-6 induces DNA damage in breast cancer cells and is an attractive model for developing innovative therapeutic agents against breast cancer.

Protective effect of aspirin against mitomycin C-induced carcinogenicity, assessed by the test for detection of epithelial tumor clones (warts) in Drosophila melanogaster.

The present study assessed the protective effect of aspirin against carcinogenicity induced by mitomycin C (MMC) by the test for detection of warts/epithelial tumor clones in Drosophila melanogaster. Larvae were treated with different concentrations of aspirin alone (10, 20 or 40 mg/mL) or aspirin in association with MMC. MMC and ultrapure water were employed as the positive and negative control, respectively. Antioxidant activity was determined using the DPPH method. For performing cytotoxicity assay on HeLa cells, the aspirin concentrations used ranged from 200 mmol/L to 3,125 mmol/L. For assessment of apoptosis and necrosis, cells were incubated for 24 h with complete medium in the absence (control group) or presence of aspirin (12.5 mmol/L and 25 mmol/L). The results obtained in the assessment of the possible carcinogenic effects of aspirin at the three concentrations tested indicate no statistically significant increase in tumor frequency compared to the negative control. The anticarcinogenic activity assessment, where the larvae of D. melanogaster were previously induced to tumor formation by MMC and later treated with aspirin, showed a statistically significant reduction in the number of tumors compared to the positive control. Antioxidant activity across the three aspirin concentrations (10, 20 or 40 mg/mL) ranged from 20.81% to 26.5%. It was observed that aspirin reduced growth viability of HeLa cells in a concentration-dependent manner in comparison with the control. These results indicate that aspirin did not induce tumors in Drosophila and reduced MMC-induced carcinogenicity. The antioxidant activity and apoptosis induction appear to be the main mechanisms involved in reducing the frequency of tumors.

Genotoxic effects of BnSP-6, a Lys-49 phospholipase A2 (PLA2) homologue from Bothrops pauloensis snake venom, on MDA-MB-231 breast cancer cells

Herein we evaluated the genotoxic effects of BnSP-6, a Lys-49 phospholipase A2 (PLA2) from Bothrops pauloensis, on breast cancer cells. BnSP-6 was able to induce a higher cytotoxic and genotoxic activity in MDA-MB-231 cells, when compared to MCF10A (a non-tumorigenic breast cell line), suggesting that this protein presented a possible preference for cancer cells. BnSP-6 inhibited MDA-MB-231 proliferation at 24, 48 and 72?h. In addition, BnSP-6 induced significant increase in the percentage of TUNEL-positive cells, a marker of DNA damage. To obtain novel insight into the direct DNA damage interference in MDA-MB-231 survival and proliferation, we evaluated cell cycle progression. BnSP-6 produced a significant decrease in 2N (G1) and an increase in the G2/M phase and this capacity is likely related to the modulation of expression of progression cell cycle-associated genes (CCND1, CCNE1, CDC25A, CHEK2, E2F1, CDH-1 and NF-kB). Taken together, these results indicate that BnSP-6 induces DNA damage in breast cancer cells and is an attractive model for developing innovative therapeutic agents against breast cancer.

Genotoxic effects of BnSP-6, a Lys-49 phospholipase A2 (PLA2) homologue from Bothrops pauloensis snake venom, on MDA-MB-231 breast cancer cells

Herein we evaluated the genotoxic effects of BnSP-6, a Lys-49 phospholipase A2 (PLA2) from Bothrops pauloensis, on breast cancer cells. BnSP-6 was able to induce a higher cytotoxic and genotoxic activity in MDA-MB-231 cells, when compared to MCF10A (a non-tumorigenic breast cell line), suggesting that this protein presented a possible preference for cancer cells. BnSP-6 inhibited MDA-MB-231 proliferation at 24, 48 and 72?h. In addition, BnSP-6 induced significant increase in the percentage of TUNEL-positive cells, a marker of DNA damage. To obtain novel insight into the direct DNA damage interference in MDA-MB-231 survival and proliferation, we evaluated cell cycle progression. BnSP-6 produced a significant decrease in 2N (G1) and an increase in the G2/M phase and this capacity is likely related to the modulation of expression of progression cell cycle-associated genes (CCND1, CCNE1, CDC25A, CHEK2, E2F1, CDH-1 and NF-kB). Taken together, these results indicate that BnSP-6 induces DNA damage in breast cancer cells and is an attractive model for developing innovative therapeutic agents against breast cancer.

Chromosomal disruption and rearrangements during murine sarcoma development converge to stable karyotypic formation kept by telomerase overexpression.

BACKGROUND: Tumor initiation presents a complex and unstable genomic landscape; one of the earliest hallmark events of cancer, and its progression is probably based on selection mechanisms under specific environments that lead to functional tumor cell speciation. We hypothesized that viable tumor phenotypes possess common and highly stable karyotypes and their proliferation is facilitated by an attuned high telomerase activity. Very few investigations have focused on the evolution of common chromosomal rearrangements associated to molecular events that result in functional phenotypes during tumor development. RESULTS: We have used cytogenetic, flow cytometry and cell culture tools to investigate chromosomal rearrangements and clonality during cancer development using the murine sarcoma TG180 model, and also molecular biology techniques to establish a correlation between chromosome instability and telomerase activity, since telomeres are highly affected during cancer evolution. Cytogenetic analysis showed a near-tetraploid karyotype originated by endoreduplication. Chromosomal rearrangements were random events in response to in vitro conditions, but a stable karyotypic equilibrium was achieved during tumor progression in different in vivo conditions, suggesting that a specific microenvironment may stabilize the chromosomal number and architecture. Specific chromosome aberrations (marker chromosomes) and activated regions (rDNAs) were ubiquitous in the karyotype, suggesting that the conservation of these patterns may be advantageous for tumor progression. High telomerase expression was also correlated with the chromosomal rearrangements stabilization. CONCLUSIONS: Our data reinforce the notion that the sarcoma cell evolution converges from a highly unstable karyotype to relatively stable and functional chromosome rearrangements, which are further enabled by telomerase overexpression.

Contributions of cytogenetics to cancer research / Contribuições da citogenética em pesquisas sobre o câncer

The two conflicting visions of tumorigenesis that are widely discussed are the gene-mutation hypothesis and the aneuploidy hypothesis. In this review we will summarize the contributions of cytogenetics in the study of cancer cells and propose a hypothetical model to explain the influence of cytogenetic events in carcinogenesis, emphasizing the role of aneuploidy. The gene mutation hypothesis states that gene-specific mutations occur and that they maintain the altered phenotype of the tumor cells, and the aneuploidy hypothesis states that aneuploidy is necessary and sufficient for the initiation and progression of malignant transformation. Aneuploidy is a hallmark of cancer and plays an important role in tumorigenesis and tumor progression. Aneuploid cells might be derived from polyploid cells, which can arise spontaneously or are induced by environmental agents or chemical compounds, and the genetic instability observed in polyploid cells leads to chromosomal losses or rearrangements, resulting in variable aberrant karyotypes. Because of the large amount of evidence indicating that the correct chromosomal balance is crucial to cancer development, cytogenetic techniques are important tools for both basic research, such as elucidating carcinogenesis, and applied research, such as diagnosis, prognosis and selection of treatment. The combination of classic cytogenetics, molecular cytogenetics and molecular genetics is essential and can generate a vast amount of data, enhancing our knowledge of cancer biology and improving treatment of this disease.

As duas visões conflitantes da tumorigênese que são amplamente discutidas são a hipótese da mutação gênica e a hipótese da aneuploidia. Nesta revisão vamos resumir as contribuições da citogenética no estudo das células tumorais e propor um modelo hipotético para explicar a influência dos eventos citogenéticos na carcinogênese, enfatizando o papel da aneuploidia. A teoria da mutação gênica estabelece que mutações específicas ocorrem e mantêm o fenótipo alterado das células de um tumor, enquanto a hipótese da aneuploidia estabelece que a aneuploidia é necessária e suficiente para a iniciação e progressão da transformação maligna. A aneuploidia é considerada um marcador do câncer e esta desempenha um importante papel tanto na tumorigênese, quanto na progressão tumoral. Células aneuplóides podem ser derivadas de células poliplóides, que surgem espontaneamente ou são induzidas por agentes ambientais ou compostos químicos. A instabilidade genética observada em células poliplóides leva a perdas ou rearranjos cromossômicos, resultando em cariótipos variavelmente aberrantes. Devido à grande quantidade de evidências indicando que um balanço cromossômico correto é crucial para o desenvolvimento do câncer, as técnicas citogenéticas são ferramentas importantes tanto para a pesquisa básica, tais como pesquisas para elucidar a carcinogênese, quanto pesquisas aplicadas, como no diagnóstico, prognóstico e escolha do tratamento. A combinação da citogenética clássica, citogenética molecular e genética molecular é essencial e pode gerar uma grande quantidade de dados, aumentando o nosso conhecimento da biologia do câncer, melhorando assim o tratamento desta doença.

In vitro and in vivo antitumor effect of trachylobane-360, a diterpene from Xylopia langsdorffiana.

Trachylobane-360 (ent-7α-acetoxytrachyloban-18-oic acid) was isolated from Xylopia langsdorffiana. Studies have shown that it has weak cytotoxic activity against tumor and non-tumor cells. This study investigated the in vitro and in vivo antitumor effects of trachylobane-360, as well as its cytotoxicity in mouse erythrocytes. In order to evaluate the in vivo toxicological aspects related to trachylobane-360 administration, hematological, biochemical and histopathological analyses of the treated animals were performed. The compound exhibited a concentration-dependent effect in inducing hemolysis with HC50 of 273.6 µM, and a moderate in vitro concentration-dependent inhibitory effect on the proliferation of sarcoma 180 cells with IC50 values of 150.8 µM and 150.4 µM, evaluated by the trypan blue exclusion test and MTT reduction assay, respectively. The in vivo inhibition rates of sarcoma 180 tumor development were 45.60, 71.99 and 80.06% at doses of 12.5 and 25 mg/kg of trachylobane-360 and 25 mg/kg of 5-FU, respectively. Biochemical parameters were not altered. Leukopenia was observed after 5-FU treatment, but this effect was not seen with trachylobane-360 treatment. The histopathological analysis of liver and kidney showed that both organs were mildly affected by trachylobane-360 treatment. Trachylobane-360 showed no immunosuppressive effect. In conclusion, these data reinforce the anticancer potential of this natural diterpene.