Antioxidant-modulated cytotoxicity of silver nanoparticles.

The properties of silver nanoparticles (AgNPs) synthesized using compounds exhibiting biological activity seem to constitute an interesting issue worthy of examination. In these studies, two types of AgNPs were synthesized by a chemical reduction method using well-known antioxidants: gallic acid (GA) and ascorbic acid (AA). Transmission electron microscopy (TEM) and atomic force microscopy (AFM) revealed that the AgNPs were spherical. The average size was equal to 26 ± 6 nm and 20 ± 7 nm in the case of ascorbic acid-silver nanoparticles (AAgNPs) and gallic acid-silver nanoparticles (GAAgNPs), respectively. Surface-enhanced Raman spectroscopy (SERS) confirmed that the AgNPs were not stabilized by pure forms of applied antioxidants. Changes in mitochondrial activity and secretion of inflammatory and apoptosis mediators after the exposure of human promyelocytic (HL-60) and histiocytic lymphoma (U-937) cells to the AgNPs were studied to determine the impact of stabilizing layers on nanoparticle toxicity. The GAAgNPs were found to be more toxic for the cells than the AAgNPs. Their toxicity was manifested by a strong reduction in mitochondrial activity and induction of the secretion of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and caspase-9. The addition of pure antioxidants to the AgNP suspensions was found to influence their toxicity. There was a significant positive effect in the case of the mixture of AA with AAgNPs and GA with GAAgNPs. The results obtained suggest that the presence of stabilizing agents adsorbed on the surface of AgNPs is the main factor in shaping their toxicity. Nevertheless, the toxic effect can be also tuned by the introduction of free antioxidant molecules to the AgNP suspensions.

Carnosic acid exhibits antiproliferative and proapoptotic effects in tumoral NCI-H460 and nontumoral IMR-90 lung cells.

Carnosic acid (CA) is a phenolic diterpene with many important biological activities including antimicrobial, antioxidant, anti-inflammatory properties, and anti-proliferative properties. The aim of the present study was to investigate cytotoxic activity, cell cycle, apoptotic, and molecular effects attributed to CA in non-tumoral IMR-90 (human fetal lung fibroblasts), as well as tumoral NCI-H460 (human non-small-cell lung cancer) cell lines. Cell proliferation was evaluated by Real-Time Cell Analysis system, while apoptosis and cell cycle were assessed using flow cytometry. RT-qPCR was used to estimate the relative expression of genes involved in cell cycle regulation, DNA damage and repair, and apoptosis induction. CA inhibited proliferation of IMR-90 and NCI-H460 cells via cell cycle arrest at G0/G1 and G2/M phases, according to the treatment concentration. The mRNA levels of genes encoding cyclins A2, B1, and B2 were downregulated in response to CA treatment of IMR-90 cells. Apoptosis was induced and proapoptotic gene PUMA was upregulated in both cell lines. mRNA levels of genes ATR, CCND1, CHK1, CHK2, MYC, GADD45A, H2AFX, MTOR, TP53, and BCL2, CASP3 were not markedly changed following CA treatments. Although CA exerted antiproliferative activity against NCI-H460 tumor cells, this phytochemical induced toxic effects in non-tumoral cells, and thus needs to be considered carefully prior to pharmacological use therapeutically.

Role of Tumor Microenvironment in Pituitary Neuroendocrine Tumors: New Approaches in Classification, Diagnosis and Therapy.

Adenohypophysal pituitary tumors account for 10-15% of all intracranial tumors, and 25-55% display signs of invasiveness. Nevertheless, oncology still relies on histopathological examination to establish the diagnosis. Considering that the classification of pituitary tumors has changed significantly in recent years, we discuss the definition of aggressive and invasive tumors and the latest molecular criteria used for classifying these entities. The pituitary tumor microenvironment (TME) is essential for neoplastic development and progression. This review aims to reveal the impact of TME characteristics on stratifying these tumors in view of finding appropriate therapeutic approaches. The role of the pituitary tumor microenvironment and its main components, non-tumoral cells and soluble factors, has been addressed. The variable display of different immune cell types, tumor-associated fibroblasts, and folliculostellate cells is discussed in relation to tumor development and aggressiveness. The molecules secreted by both tumoral and non-tumoral cells, such as VEGF, FGF, EGF, IL6, TNFα, and immune checkpoint molecules, contribute to the crosstalk between the tumor and its microenvironment. They could be considered potential biomarkers for diagnosis and the invasiveness of these tumors, together with emerging non-coding RNA molecules. Therefore, assessing this complex network associated with pituitary neuroendocrine tumors could bring a new era in diagnosing and treating this pathology.

Vasculogenic Mimicry-An Overview.

Vasculogenic mimicry (VM), a tumor microcirculation model found in melanoma in the last 20 years, is a vascular channel-like structure composed of tumor cells, but without endothelial cells, that stains positive for periodic acid-Schiff (PAS) and negative staining for CD31. VM provides, to the highly aggressive malignant tumor cells, adequate oxygen and nutrient supply for tumor growth and subsequent metastasis process and its presence are related to poor prognosis in patients. VM is independent of endothelial cells, which may partly explain why angiogenesis drug inhibitors have not achieved the expected success for cancer treatment.

3D Cell Cultures as Prospective Models to Study Extracellular Vesicles in Cancer.

The improvement of culturing techniques to model the environment and physiological conditions surrounding tumors has also been applied to the study of extracellular vesicles (EVs) in cancer research. EVs role is not only limited to cell-to-cell communication in tumor physiology, they are also a promising source of biomarkers, and a tool to deliver drugs and induce antitumoral activity. In the present review, we have addressed the improvements achieved by using 3D culture models to evaluate the role of EVs in tumor progression and the potential applications of EVs in diagnostics and therapeutics. The most employed assays are gel-based spheroids, often utilized to examine the cell invasion rate and angiogenesis markers upon EVs treatment. To study EVs as drug carriers, a more complex multicellular cultures and organoids from cancer stem cell populations have been developed. Such strategies provide a closer response to in vivo physiology observed responses. They are also the best models to understand the complex interactions between different populations of cells and the extracellular matrix, in which tumor-derived EVs modify epithelial or mesenchymal cells to become protumor agents. Finally, the growth of cells in 3D bioreactor-like systems is appointed as the best approach to industrial EVs production, a necessary step toward clinical translation of EVs-based therapy.

Nanoceria acts as antioxidant in tumoral and transformed cells.

Antioxidant/prooxidant properties of cerium oxide nanoparticles (nanoceria) have been reported. It has been proposed that this protective/adverse role would depend of the cell status. In tumoral cells, nanoceria would act as prooxidant, while in normal cells it would act as antioxidant. In this context our work aims to study the nanoceria antioxidant/prooxidant capacity in different tumoral cell lines, studying how cell origin (non-tumoral vs tumoral), or extracellular environment could affect its protective/adverse effect. We have determined the ability of nanoceria to reduce the levels of reactive-oxygen-species (ROS) generated by the antitumoral agent cisplatin in five human tumoral cells. Results indicate that combined treatment reduces the levels of induced ROS in practically all cases. Prooxidant effects were never observed. The growth of A549 cell line in a forced acidic environment showed that the antioxidant properties of nanoceria were not influenced. A normal mouse embryonic fibroblast cell line (MEF) and its arsenic-transformed isogenic counterpart (AsT-MEF) were also evaluated. As in the other cases, nanoceria elicited an antioxidant effect in both MEF and AsT-MEF. In addition, nanoceria pretreatment also reduced the levels of apoptosis and cell death induced by cisplatin. From our results, we can conclude that the tumoral state of the cells is not a general argument to explain a potential non-protective role of nanoceria.

Toxicity of silver nanoparticles towards tumoral human cell lines U-937 and HL-60.

The toxicity of three types of silver nanoparticles towards histiocytic lymphoma (U-937) and human promyelocytic cells (HL-60) was studied. The nanoparticles were synthesized in a chemical reduction method using sodium borohydride. Trisodium citrate and cysteamine hydrochloride were used to generate a negative and positive nanoparticle surface charge. The evaluation of cell viability, membrane integrity, antioxidant activity and the induction of inflammation were used to evaluate the difference in cellular response to the nanoparticle treatment. The results revealed that the cysteamine-stabilized (positively charged) nanoparticles (SBATE) were the least toxic although they exhibited a similar ion release profile as the unmodified (negatively charged) nanoparticles obtained using sodium borohydride (SBNM). Citrate-stabilized nanoparticles (SBTC) induced superoxide dismutase (SOD) activity in the HL-60 cells and total antioxidant activity in the U-937 cells despite their resistance to oxidative dissolution. The toxicity of SBNM nanoparticles was manifested in the disruption of membrane integrity, decrease in the mitochondrial functions of cells and the induction of inflammation. These findings allowed to conclude that mechanism of silver nanoparticle cytotoxicity is the combination of effects coming from the surface charge of nanoparticles, released silver ions and biological activity of stabilizing agent molecules.

Las células prostáticas en la circulación sanguínea en pacientes con cáncer prostático expresan la proteína P504S: un estudio utilizando inmunocitoquímica / Circulating prostate cells in patients with prostate cancer express P504S: an immunocytochem

Determinar la presencia de células prostáticas en la circulación sanguínea (CPCs) en pacientes con cáncer prostático y la expresión de P504S. Método: Las células mononucleares fueron separadas de la sangre venosa por centrifugación diferencial, e identificadas utilizando anticuerpos monoclonales contra APE y P504S. Diez mujeres fueron usadas como controles. 66 hombres con cáncer prostático formaron el grupo de estudio. Resultados: 69,7 por ciento tuvieron células prostáticas en la sangre venosa, todas las células detectadas fueron positivas para la expresión de P504S. Conclusiones: La detección de células prostáticas P504S positivas en biopsias de la próstata esutilizando para el diagnóstico de cáncer, células benignas no se expresan el antígeno. Este es el primer estudio que demuestra la expresión de P504S en CPCs, con la inferencia que estas células son malignas.

To determine the expression of P504S en circulating prostate cells (CPCs) in men with prostate cancer. Method: Mononuclear cells were separated from venous blood using differential centrifugation andidentified using monoclonal antibodies against PSA and P504S. 10 women were used as controls and 66 men with prostate cancer formed the study group. Results: 69.7 percent of men were positive for CPCs, all the CPCs detected expressed the antigen P504S. Conclusions: The detection of P504S positive cells in prostate biopsies is used to determine whether they are malignant or not, benign cells are P504S negative. This is the first study to show that CPCsare P504S with the implication that they are malignant cells.