Cytostatic Compounds Research Articles

Analytical strategies for assessing occupational exposure to antineoplastic drugs in healthcare workplaces

Cytotoxic antineoplastic drugs (ADs), widely used in treating cancer, are considered hazardous in the workplace and thus require safe handling practices. An analytical protocol for environmental and biological AD monitoring in the healthcare environment has been developed, since Europe lacks clear guidelines and regulations for cytostatic preparation and handling. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for measuring contemporaneously 20 multi-class cytostatic compounds and urinary α-fluoro-β-alanine, whereas platinum was detected by inductively coupled plasma mass spectrometry (ICP-MS). Sampling procedures and analytical conditions were optimized and the assays were validated. Environmental AD monitoring data, collected in 2009-2017, for a total of 3749 wipe tests and 57 720 determinations, was evaluated. The proportion of positive samples gradually decreased from 11.7% in 2010 to 1% in 2017, however, 2266 determinations were positive. No urine sample had detectable concentrations of any of the 4 drugs considered (0/398 samples). These improvements are so large that the key role played by the new, more stringent rules for preparing and administering ADs is evident. Hence, the analytical method involving multi-element determinations allows for a more thorough and complete investigation into the AD contamination of work environments. Med Pr 2018;69(6):589-604.

Mifepristone inhibits non-small cell lung carcinoma cellular escape from DNA damaging cisplatin

BackgroundLung cancer is the leading cause of cancer deaths in the world. The major histopathological subtype of lung cancer is non-small cell lung cancer (NSCLC). Platinum-based therapy is the standard of care for patients with advanced stage NSCLC. However, even with treatment, most patients will die of this disease within 5 years and most of these deaths are due to recurrence. One strategy to inhibit recurrence is to use cytostatic compounds following courses of lethal chemotherapy. We have shown in various cancer cell types that mifepristone (MF), an anti-progestin/anti-glucocorticoid, is a powerful cytostatic anti-cancer agent. Thus, in this work we tested the hypothesis that MF should be efficacious in inducing cytostasis and preventing repopulation of NSCLC following cisplatin (CDDP) therapy.MethodsWe established an in vitro approach wherein human NSCLC cells with different genetic backgrounds and sensitivities to CDDP (A549 and H23) were exposed to rounds of lethal concentrations of CDDP for 1 h followed or not by MF monotherapy. Every 2 days, cell number, cell viability, and colony-forming ability of viable cells were studied.ResultsCDDP killed the majority of cells, yet there were remnant cells escaping CDDP lethality and repopulating the culture, as evidenced by the improved clonogenic survival of viable cells. In contrast, when cells exposed to CDDP where further treated with MF following CDDP removal, their number and clonogenic capacity were reduced drastically.ConclusionThis study reports that there is repopulation of NSCLC cells following a lethal concentration of CDDP monotherapy, that NSCLC cells are sensitive to the growth inhibition properties of MF, and that MF abrogates the repopulation of NSCLC cells following CDDP therapy. Our study supports further evaluating MF as an adjuvant therapy for NSCLC.

Applications of Fabric Phase Sorptive Extraction to the Determination of Micropollutants in Liquid Samples

The occurrence of organic micropollutants (OMPs) in the environment is a global concern due to their potential ecological risks. Several studies have shown that some OMPs are widely detected in environmental matrices such as surface water and sewage. Wastewater treatment plants (WWTPs) have received international attention over past decades because they are considered the greatest source of aquatic environmental contamination by anthropogenic micropollutants. Intensive sampling and analysis have been globally made to improve understanding of the occurrence, behavior and fate of OMPs in WWTPs using different types of analytical approach. Recently, special awareness has been devoted to developing new effective strategies to extract the micropollutants of wastewater. In particular, microextraction protocols have gained popularity because of their simplicity, low cost and in-field application for environmental analysis. Among these, fabric phase sorptive extraction (FPSE) is reported as an excellent approach due to its properties, not only reducing the required time but also employing minor solvent volume. In this overview, we summarize the results obtained by the Research Group of Environmental Chemical Analysis of the University of Las Palmas de Gran Canaria (Spain) using this technique. Its aim is to show the potential of FPSE for the extraction of some micropollutants, such as personal care products (benzotriazole ultraviolet stabilizers (BUVSs)) and pharmaceuticals (steroid hormones and cytostatic compounds) in different liquid samples, prior to their determination by liquid chromatography.

Greater Celandine's Ups and Downs-21 Centuries of Medicinal Uses of Chelidonium majus From the Viewpoint of Today's Pharmacology.

As antique as Dioscorides era are the first records on using Chelidonium as a remedy to several sicknesses. Inspired by the “signatura rerum” principle and an apparent ancient folk tradition, various indications were given, such as anti-jaundice and cholagogue, pain-relieving, and quite often mentioned—ophthalmological problems. Central and Eastern European folk medicine has always been using this herb extensively. In this region, the plant is known under many unique vernacular names, especially in Slavonic languages, associated or not with old Greek relation to “chelidon”—the swallow. Typically for Papaveroidae subfamily, yellow-colored latex is produced in abundance and leaks intensely upon injury. Major pharmacologically relevant components, most of which were first isolated over a century ago, are isoquinoline alkaloids—berberine, chelerythrine, chelidonine, coptisine, sanguinarine. Modern pharmacology took interest in this herb but it has not ended up in gaining an officially approved and evidence-based herbal medicine status. On the contrary, the number of relevant studies and publications tended to drop. Recently, some controversial reports and sometimes insufficiently proven studies appeared, suggesting anticancer properties. Anticancer potential was in line with anecdotical knowledge spread in East European countries, however, in the absence of directly-acting cytostatic compounds, some other mechanisms might be involved. Other properties that could boost the interest in this herb are antimicrobial and antiviral activities. Being a common synanthropic weed or ruderal plant, C. majus spreads in all temperate Eurasia and acclimates well to North America. Little is known about the natural variation of bioactive metabolites, including several aforementioned isoquinoline alkaloids. In this review, we put together older and recent literature data on phytochemistry, pharmacology, and clinical studies on C. majus aiming at a critical evaluation of state-of-the-art from the viewpoint of historical and folk indications. The controversies around this herb, the safety and drug quality issues and a prospective role in phytotherapy are discussed as well.

Induction of micronuclei by four cytostatic compounds in human hematopoietic stem cells and human lymphoblastoid TK6 cells

For mutagenicity testing, primary lymphocytes or mammalian cell lines are employed. However, the true target for carcinogenic action of mutagenic chemicals may be stem cells. Since hematopoietic cancers induced by chemical agents originate at the hematopoietic stem cell (HSC) stage and since one of the side effects of chemotherapeutic cancer treatment is the induction of secondary tumors, often leukemias, HSC may be a suitable cell system. We compared the sensitivity of HSC with the genotoxicity testing cell line TK6 for chromosomal mutations. HSC were less sensitive than TK6 cells for the genotoxic effects of the model genotoxins and chemotherapeutic agents doxorubicin, vinblastine, methyl methanesulfonate (MMS) and equally sensitive for mitomycin C (MMC). However, loss of viability after mitomycin C treatment was higher in HSC than in TK6 cells. Among the factors that may influence sensitivity for genomic damage, the generation or response to reactive oxygen species (ROS) and the effectiveness of DNA damage response can be discussed. Here we show that HSC can be used in a standard micronucleus test protocol for chromosomal mutations and that their sensitivity was not higher than that of a classical testing cell line.

Inhibition of seed germination, toxicity on Artemia salina and phytochemical prospecting with from Cuban plants as indicator of antitumo activity

Cuba has a high biodiversity and many plants are widely known and used in folk medicine and for commercial manufacturing of phytomedicines. However, many plants have not been studied for their pharmacological properties, particularly endemic plants. Two simple, inexpensive and rapid biological assays, inhibition of germination of tomato and lettuce seeds and toxicity on the brine shrimp A. salina, have been evaluated as prescreens for possible antitumor activity. Extracts of six plant species collected in Havana, Cuba were subjected to the brine shrimp lethality test and inhibition of seed germination in order to detect potential sources of novel cytotoxic and cytostatic antitumor compounds, respectively. The larvicidal activity, based on the percentage of larval mortality, was evaluated after 24 h exposure to the treatments. In the case of inhibition of seed germination the readings were made 48 h after exposure. Semi-quantitative phytochemical prospecting was done by color and precipitation reactions for chemical functional groups. All species tested showed some cytotoxic and cytostatic effects. Two extracts showed high cytotoxicity in the Artemia salina test, the methanol extract from flowers of Tithonia diversifolia (TD) with IC50 (Inhibitory concentration 50) or LD50 (Lethal doses 50) of 1.14 µg/mL and methanol extract of stems from Castela lucida (CL) with LD50 of 0.052 µg/mL. However, the more promising species was the Tabebuia hypoleuca (TH) with cytostatic effect superior of 65% and good cytotoxic effect with the leaf extract, with the prominent compound classes’ triterpenes, tannins, phenols, and alkaloids. Keywords: Cuban plants; cytotoxic; Artemia salina; cytostatic; seed germination; chemical compounds

Optimization and application of fabric phase sorptive extraction coupled to ultra-high performance liquid chromatography tandem mass spectrometry for the determination of cytostatic drug residues in environmental waters

Every year, hundreds of tons of organic pollutants reach the environment through effluents released from wastewater treatment plants worldwide, and many of these compounds have harmful effects on the aquatic ecosystem. A new class of emerging pollutants of high concern is cytostatic drugs, which are designed to treat different types of cancers by attacking cells. Environmental concentrations of cytostatic drugs are known to be in the range of ngL−1, and for this reason, it is imperative to develop analytical methods of extraction and preconcentration to allow for subsequent instrumental analysis of these drugs.In this work, a rapid, simple and green method for the analysis of seven cytostatic drug compounds that are commonly used in anti-cancer therapies was developed using a novel extraction process based on a powerful miniaturized technique, fabric phase sorptive extraction (FPSE) coupled to ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS).The major parameters that affect the extraction process were optimized. The new method shows good linearity, with a relative standard deviation (RSD) of less than 12%. Relative recoveries higher than 40% were obtained for the studied compounds, and the detection limit of the method was within the values at which these compounds are usually found in environmental water (0.20ngL−1 to 80ngL−1). The Limit of Quantification ranged from 0.68 to 267ngL−1. Significant suppression of the signal due to the matrix effect, a common shortcoming attributed to interference from the extraction process as well as the use of ionization mode, was not observed. Subsequently, the method was applied to real wastewater samples from an effluent obtained from a hospital area and three wastewater treatment plants located in Gran Canaria Island, Spain.

BRD9 Inhibition, Alone or in Combination with Cytostatic Compounds as a Therapeutic Approach in Rhabdoid Tumors

Rhabdoid tumors (RT) are malignant neoplasms of early childhood. Despite intensive therapy, survival is poor and new treatment approaches are required. The only recurrent mutations in these tumors affect SMARCB1 and less commonly SMARCA4, both subunits of the chromatin remodeling complex SWItch/Sucrose Non-Fermentable (SWI/SNF). Loss of these two core subunits alters the function of the SWI/SNF complex, resulting in tumor development. We hypothesized that inhibition of aberrant SWI/SNF function by selective blockade of the BRD9 subunit of the SWI/SNF complex would reduce tumor cell proliferation. The cytotoxic and anti-proliferative effects of two specific chemical probes (I-BRD9 and BI-9564) which target the bromodomain of SWI/SNF protein BRD9 were evaluated in 5 RT cell lines. Combinatorial effects of I-BRD9 and cytotoxic drugs on cell proliferation were evaluated by cytotoxicity assays. Single compound treatment of RT cells with I-BRD9 and BI-9564 resulted in decreased cell proliferation, G1-arrest and apoptosis. Combined treatment of doxorubicin or carboplatin with I-BRD9 resulted in additive to synergistic inhibitory effects on cell proliferation. In contrast, the combination of I-BRD9 with vincristine demonstrated the antagonistic effects of these two compounds. We conclude that the BRD9 bromodomain is an attractive target for novel therapies in this cancer.

Development of a macroporous ceramic passive sampler for the monitoring of cytostatic drugs in water

The aim of this study was to develop and calibrate a macroporous ceramic passive sampler (MCPS) for the monitoring of anticancer drugs in wastewater. This system was designed by the Spanish Research Council (CSIC) and consists in a porous ceramic tube to allow a high diffusion of contaminants. The MCPS has been calibrated for 16 cytostatic drugs over time periods up to 9 d in spiked water under controlled laboratory conditions. Optimal uptake was accomplished for 7 compounds, namely ifosfamide, cyclophosphamide, capecitabine, prednisone, megestrol, cyproterone and mycophenolic acid, whereas cytarabine was not adsorbed in the receiving phase and the rest were hydrolyzed over the deployment period. The sampling rate for these 7 compounds was between 0.825 and 3.350 mL day−1 and the diffusion coefficients varied from 1.01E-07 to 4.12E-07 cm2 s−1. To prove the applicability of the MCPSs, samplers (n = 3) were deployed in influent and effluent waters of a WWTP for a period of 6 d and results were compared to grab sampling and extraction with Solid Phase Extraction (SPE). In influent waters, MCPS were clogged due to the high amount of suspended solids in these waters. In effluents, MCPS detected cyclophosphamide and mycophenolic acid at concentrations of 19 ± 3 and 136 ± 28 ng L−1 with a good agreement with the levels obtained by grab sampling. The study discusses the use and performance of the MCPS for the monitoring of stable cytostatic compounds in a complex matrix such as wastewater.

On the Interactions of Fused Pyrazole Derivative with Selected Amino Acids: DFT Calculations

Due to the increasing prevalence of neoplasms, there is a permanent need for new selective cytostatic compounds. Anticancer drugs can act in different ways, affecting protein expression and synthesis, including disruption of signaling pathways within cells. Continuing our previous research aiming at elucidating the mechanism of pyrazole’s anticancer activity, we carried out in silico studies on the interactions of fused pyrazole derivative with alanine, lysine, glutamic acid, and methionine. The objective of the study is to improve our understanding of the possible interactions of pyrazole derivatives with the above-mentioned amino acids. For this purpose, we apply the DFT formalism (optimization using the B3LYP, CAM-B3LYP, PBE0, and M06L functionals) and interaction energy calculations (counterpoise corrected method based on the basis set superposition error, BSSE) together with QTAIM approach and estimation of the 1H NMR chemical shifts of analyzed pyrazole derivative using different basis sets and DFT functionals in CPCM solvation model (and water used as a solvent).

Substituted Tetrahydroisoquinolines as Microtubule-destabilizing Agents in Triple Negative Human Breast Cancer Cells.

Triple-negative breast cancer (TNBC) occurs at greater frequency amongst African-Americans, being characterized by the absence of estrogen receptor (ER), progesterone receptor (PR) and human epidermal receptor 2 (HER2). TNBC is often invasive and typically treated with cytostatic agents such as taxanes in combination with anthracyclines or platinum-based drugs. In this study, we synthesized a number of tetrahydroisoquinoline moieties by N-amination of substituted isoquinolines by O-mesytelene sulfonylhydroxylamine followed by ylide formation and reduction, which yielded the desired, substituted tetrahydroisoquinolines (THIQs) in moderate to good yield. Using a differential scatter plot to identify potential selective ER-modulating drugs in ER-positive control cells (MCF-7) driven by estradiol vs. TNBC (MDA-MB-231) cells, the in vitro data showed an absence of effects on the ER (compared to 4-hydroxytamoxifen and raloxifene). In contrast, two lead compounds halted proliferation (cytostatic) in MDA-MB-231 TNBC cells at a potency level below 2.5 μM concomitant with mitotic arrest, attenuated replicative DNA synthesis, halted microtubule nucleation/stunted tubulin polymerization, abnormal expansive cytoskeletal tubulin and actin morphologies with multinucleation of cells. The most effective cytostatic compounds GM-4-53 and GM-3-121 blocked replicative processes at the G2 growth phase. These findings suggest that specific THIQs work independently of the ER, by holding static the microtubule network thereby preventing mitosis. Future work is required to establish the safety and efficacy of these drugs and their potential adjunct therapeutic gain in the presence of taxanes in TNBC.

Biological and photochemical degradation of cytostatic drugs under laboratory conditions

Cytostatic drugs, used in chemotherapy, have emerged as new environmental contaminants due to their recurrent presence in surface waters and genotoxic effects. Yet, their degradability and environmental fate is largely unknown. The aim of this study was to determine the degradation kinetics of 16 cytostatic drugs, prioritized according to their usage and occurrence in hospital and wastewater treatment plants (WWTP) effluents, through the following laboratory scale processes: hydrolysis, aerobic biodegradation, UV-C photolysis, UV-C/H2O2 and simulated solar radiation. Some drugs were unstable in milli-Q water (vincristine, vinblastine, daunorubicin, doxorubicin and irinotecan); others were photodegraded under UV-C light (melphalan and etoposide) but some others were found to be recalcitrant to biodegradation and/or UV-C, making necessary the use of advanced oxidation processes (AOPs) such as UV-C/H2O2 for complete elimination (cytarabine, ifosfamide and cyclophosphamide). Finally, radiation in a solar box was used to simulate the fate of cytostatic drugs in surface waters under natural radiation and complete removal was not observed for any drug. The degradation process was monitored using liquid chromatography coupled to high resolution mass spectrometry and pseudo-first order kinetic degradation constants were calculated. This study provides new data on the degradability of cytostatic compounds in water, thus contributing to the existing knowledge on their fate and risk in the environment.

Ozonation of hospital raw wastewaters for cytostatic compounds removal. Kinetic modelling and economic assessment of the process

The kinetics of the ozone consumption for the pretreatment of hospital wastewater has been analysed in order to determine the reaction rate coefficients between the ozone and the readily oxidisabled organic matter and cytostatic compounds. The wastewater from a medium size hospital was treated with ozone and peroxone methodologies, varying the ozone concentration, the reaction time and the hydrogen peroxide doses. The analysis shows that there are four cytostatic compounds, i.e. irinotecan, ifosfamide, cyclophosphamide and capecitabine, detected in the wastewaters and they are completely removed with reasonably short times after the ozone treatment. Considering the reactor geometry, the gas hydrodynamics, the mass transfer of ozone from gas to liquid and the reaction of all oxidisable compounds of the wastewater it is possible to determine the chemical ozone demand, COzD, of the sample as 256mgO3L−1 and the kinetic rate coefficient with the dissolved organic matter as 8.4M−1s−1. The kinetic rate coefficient between the ozone and the cyclophosphamide is in the order of 34.7M−1s−1 and higher for the other cytostatics. The direct economic cost of the treatment was evaluated considering this reaction kinetics and it is below 0.3€/m3 under given circumstances.

Gold(I) complex of 1,1'-bis(diphenylphosphino) ferrocene-quinoline conjugate: a virostatic agent against HIV-1.

HIV infection is known for replicating in proliferating CD(+) T-cells. Treatment of these cells with cytostatic (anti-proliferation) compounds such as hydroxyurea interferes with the cells's ability support HIV replication. Combinations of such cytostatic compounds with proven anti-retroviral drugs (like ddI) are known as virostatic, and have been shown to aid in the control of the infection. The use of two different drugs in virostatic combinations however, carries the risk of adverse effects including drug-drug interactions, which could lead to augmented toxicities and reduced efficacy. Here, a novel digold(I) complex of ferrocene-quinoline (3) was investigated for cytostatic behaviour as well as anti-viral activity which if demonstrated would eliminate concerns of drug-drug interactions. The complex was synthesized and characterized by NMR, FT-IR and mass spectroscopy and the molecular structure was confirmed by X-ray crystallography. Bio-screening involved viability dyes, real time electronic sensing and whole virus assays. The complex showed significant (p=0.0092) inhibition of virus infectivity (83%) at 10 ug/mL. This same concentration caused cytostatic behaviour in TZM-bl cells with significant (p<0.01) S and G2/M phase cell cycle arrest. These data supports 3 as a virostatic agent, possessing both anti-viral and cytostatic characteristics. In the absence of 3, TZM-bl cells were infected by a pseudovirus and this was demonstrated through luminescence in a luciferase assay. Pre-incubation of the virus with 3 decreased luminescence, indicating the anti-viral activity of 3. Complex 3 also showed cytostatic behavior with increased S-phase and G2/M phase cell cycle arrest.

New spiro tria(thia)zolidine⿿acridines as topoisomerase inhibitors, DNA binders and cytostatic compounds

Three new diphenylsubstituted spirotriazolidine- and thiazolidinone⿿acridines were prepared and their interaction with calf thymus DNA investigated with UV⿿vis, fluorescence, circular dichroism spectroscopy and viscometry. The binding constants K were estimated to range from 0.34 to 0.93ÿ104M⿿1. UV⿿vis, fluorescence and circular dichroism measurements indicated that the compounds act as effective DNA-interacting agents. Electrophoretic separation proved that ligands inhibited topoisomerase I and II. The biological activity of compounds 3, 5 &6 at several different concentrations (10, 20 and 50μM) was evaluated both 48h and 72h following their addition to HL-60 cancer cells. The results were analysed using various different techniques (MMP detection, changes in metabolic activity/viability and analysis of cell cycle distribution). Acridine was also used as the positive control in these assays. The results from MMP analysis demonstrate the strong effect of 3-diphenylamino-2-(acridin-9-yl)imino-1,3-thiazolidin-4-one (5) on mitochondrial physiology. Cell viability analysis showed that acridine derivatives 3 and 6 were less effective than derivative 5 and the acridine control.

Drugs of abuse, cytostatic drugs and iodinated contrast media in tap water from the Madrid region (central Spain):A case study to analyse their occurrence and human health risk characterization

This work analyses the presence of forty-eight emerging pollutants, including twenty-five drugs of abuse and metabolites, seventeen cytostatic drugs and six iodinated contrast media, in tap water from the Madrid Region. Analysis of the target compounds in the tap water was performed by means of (on-line or off-line) solid-phase extraction followed by analysis by liquid chromatography–tandem mass spectrometry. A preliminary human health risk characterization was undertaken for each individual compound and for different groups of compounds with a common mechanism of action found in tap water.The results of the study showed the presence of eight out of the twenty-five drugs of abuse and metabolites analysed, namely, the cocainics cocaine and benzoylecgonine, the amphetamine-type stimulants ephedrine, 3,4-methylenedioxymethamphetamine and methamphetamine, the opioid methadone and its metabolite 2-ethylene-1,5-dimethyl-3,3-diphenylpyrrolidine and, finally caffeine at concentrations ranging from 0.11 to 502ngL−1. Four out of the six analysed iodinated contrast media, namely, diatrizoate, iohexol, iomeprol and iopromide, were detected in at least one sample, with concentration values varying between 0.4 and 5ngL−1. Cytostatic compounds were not detected in any sample. Caffeine was the substance showing the highest concentrations, up to 502ngL−1, mainly in the drinking water sampling point located in Madrid city. Among the other drugs of abuse, the most abundant compounds were cocaine and benzoylecgonine, detected at concentrations ranging from 0.11 to 86ngL−1 and from 0.11 to 53ngL−1, respectively. Regarding iodinated contrast media, iohexol was the most ubiquitous and abundant compound, with a frequency of detection of 100% and concentrations from 0.5 to 5.0ngL−1 in basically the same range in all sampling points.Taking into account the results and types of treatment applied, ozonisation plus granular activated carbon filtration appears to be efficient in the removal of cocaine and benzoylecgonine. For the amphetamine-type stimulants, opioids and caffeine, ozonisation plus granular activated carbon filtration and ultrafiltration plus reverse osmosis showed higher removal efficiency than sand filtration.The human health risk characterization performed indicates that the lifetime consumption of the tap waters analysed has associated a negligible human health concern.

Development and Validation of a Novel Leishmania donovani Screening Cascade for High-Throughput Screening Using a Novel Axenic Assay with High Predictivity of Leishmanicidal Intracellular Activity.

Visceral leishmaniasis is an important parasitic disease of the developing world with a limited arsenal of drugs available for treatment. The existing drugs have significant deficiencies so there is an urgent need for new and improved drugs. In the human host, Leishmania are obligate intracellular parasites which poses particular challenges in terms of drug discovery. To achieve sufficient throughput and robustness, free-living parasites are often used in primary screening assays as a surrogate for the more complex intracellular assays. We and others have found that such axenic assays have a high false positive rate relative to the intracellular assays, and that this limits their usefulness as a primary platform for screening of large compound collections. While many different reasons could lie behind the poor translation from axenic parasite to intracellular parasite, we show here that a key factor is the identification of growth slowing and cytostatic compounds by axenic assays in addition to the more desirable cytocidal compounds. We present a screening cascade based on a novel cytocidal-only axenic amastigote assay, developed by increasing starting density of cells and lowering the limit of detection, and show that it has a much improved translation to the intracellular assay. We propose that this assay is an improved primary platform in a new Leishmania screening cascade designed for the screening of large compound collections. This cascade was employed to screen a diversity-oriented-synthesis library, and yielded two novel antileishmanial chemotypes. The approach we have taken may have broad relevance to anti-infective and anti-parasitic drug discovery.

The Resazurin Reduction Assay Can Distinguish Cytotoxic from Cytostatic Compounds in Spheroid Screening Assays

Spheroid-based cellular screening approaches represent a highly physiologic experimental setup to identify novel anticancer drugs and an innovative preclinical model to reduce the high failure rate of anticancer compounds in clinical trials. The resazurin reduction (RR) assay, known as the alamarBlue or CellTiter-Blue assay, is frequently used to determine cell viability/proliferation capacity in eukaryotic cells. Whether this assay is applicable to assess viability in multicellular spheroids has not been evaluated. We analyzed the RR assay to measure cytotoxic and/or cytostatic responses in tumor cell spheroids compared with conventional 2D cultures. We found that tight cell-cell interactions in compact spheroids hamper resazurin uptake and its subsequent reduction to resorufin, leading to lowered reduction activity in relation to the actual cellular health/cell number. Treatment with staurosporine disrupted close cell-cell contacts, which increased resazurin reduction compared with untreated controls. Loss of tight junctions by trypsinization or addition of EGTA or EDTA restored high resazurin reduction rates in untreated spheroids. In conclusion, the RR assay is unsuited to quantitatively measure cellular health/cell number in compact spheroids. However, it can be used to distinguish between cytotoxic versus cytostatic compounds in spheroids. Restoration of the correlation of cell viability/number to resazurin reduction capacity can be achieved by disruption of tight junctions.

Порівняння впливу цитостатичних сполук похідного малеіміду та 5-фторурацилу на морфофункціональний стан печінки щурів за умов хемоіндукованого канцерогенезу колоректального раку

Порівняння впливу цитостатичних сполук похідного малеіміду та 5-фторурацилу на морфофункціональний стан печінки щурів за умов хемоіндукованого канцерогенезу колоректального раку

Nanoparticles in melanoma.

Malignant melanoma is one of the most common causes of cancer and cancer deaths in young people. Until few years ago, scarce drugs have proven efficacy in metastatic setting. However, in the recent years, the treatment of metastatic malignant melanoma has undergone the incorporation of effective treatment such as immunotherapy, the use of tyrosine kinase inhibitors and the emergence of other cytostatic compounds, like the nanoparticles. This review aims to propose a standardization to classify the different types of nanoparticles, according to chemical aspects, and update the clinical research with nanoparticles and their use in melanoma field.