Gold nanoparticles synthesis and biological activity estimation in vitro and in vivo

The aim of the work was the synthesis of gold nanoparticles (GNP) of different sizes and the estimation of their biological activity in vitro and in vivo. Materials and Methods: Water dispersions of gold nanoparticles of different sizes have been synthesized by Davis method and characterized by laser-correlation spectroscopy and transmission electron microscopy methods. The GNP interaction with tumor cells has been visualized by confocal microscopy method. The enzyme activity was determined by standard biochemical methods. GNP distribution and content in organs and tissues have been determined via atomic-absorption spectrometry method; genotoxic influence has been estimated by “Comet-assay” method. Results: The GNP size-dependent accumulation in cultured U937 tumor cells and their ability to modulate U937 cell membrane Na+,K+-АТР-ase activity value has been revealed in vitro. Using in vivo model of Guerin carcinoma it has been shown that GNP possess high affinity to tumor cells. Conclusions: Our results indicate the perspectives of use of the synthesized GNP water dispersions for cancer diagnostics and treatment. It’s necessary to take into account a size-dependent biosafety level of nanoparticles

Elevated 5hmC levels characterize DNA of the cerebellum in Parkinson’s disease

5-methylcytosine and the oxidation product 5-hydroxymethylcytosine are two prominent epigenetic variants of the cytosine base in nuclear DNA of mammalian brains. We measured levels of 5-methylcytosine and 5-hydroxymethylcytosine by enzyme-linked immunosorbent assay in DNA from post-mortem cerebella of individuals with Parkinson’s disease and age-matched controls. 5-methylcytosine levels showed no significant differences between Parkinson’s disease and control DNA sample sets. In contrast, median 5-hydroxymethylcytosine levels were almost twice as high (p < 0.001) in both male and female Parkinson’s disease individuals compared with controls. The distinct epigenetic profile identified in cerebellar DNA of Parkinson’s disease patients raises the question whether elevated 5-hydroxymethylcytosine levels are a driver or a consequence of Parkinson’s disease

The use of nanoferromagnetics to increase the cytotoxic effect of antitumor drugs

Aim: To investigate the influence of ferromagnetic nanoparticles on antitumor effect of doxorubicin and mitochondria oxidative phosphorylation. Methods: The study was carried out on the mice-hybrids (C57Bl/6xDBA/2) with intraperitoneally (i/p) transplantated Ehrlich ascitic carcinoma. Single i/p injection of doxorubicin (Dox), stabilized ferromagnetic nanoparticles (Fe3O4; 20–40 nm; FM) or their combination were performed 7 days after tumor transplantation. The cytotoxic effect of agents, morphology and cell cycle of tumor cells were studied 24, 48 and 72 h after Dox administration. Results: The investigations showed that ferromagnetic nanoparticles increased the cytotoxic effect of doxorubicin on Ehrlich ascіtic carcinoma mainly 48 h after agents’ administration. The largest number of apoptotic cells was observed in group of animals in which doxorubicin was administered before ferromagnetic nanoparticles. Moreover, the ferromagnetic nanoparticles at concentration 1.45 μg Fe/ml and, particularly, 7.25 μg Fe/ml decreased mitochondria oxygen consumption in phosphorylation state that may negatively influence their living capability. Conclusions: Obtained data point out the perspective of use of certain sized FM nanoparticles to increase the cytotoixc effect of antitumor drugs

Comparative analysis of promoter methylation and gene expression endpoints between tumorous and non-tumorous tissues from HCV-positive patients with hepatocellular carcinoma

Transcriptional silencing of tumor suppressor genes and other cancer-related genes induced by promoter CpG island hypermethylation is an important epigenetic mechanism of hepatocarcinogenesis. Previous studies have established methylation profiles of hepatocellular carcinomas (HCCs) and demonstrated that methylation of several candidate genes in resected tissues may be associated with time to recurrence. The goals of our study were to test whether specific promoter methylation and mRNA levels of candidate genes, as well as global changes in DNA methylation, can be linked with time to recurrence and clinicopathological variables in a homogenous study group of HCC patients. Forty-three tumorous and 45 non-tumorous liver tissue samples from the surgical margin were obtained from HCV-positive, HBV-negative HCC patients who underwent tumor resection surgery and who were monitored for tumor recurrence thereafter (median follow-up time: 16 months (range, 0 – 79 months)). Methylation-specific PCR was used to assess the promoter methylation status of P16(INK4a), SOCS-1, RASSF1A, APC, GSTP1, RIZ1, and MGMT genes, while the level of LINE-1 methylation was used as marker of global DNA methylation levels. Methylation frequencies in P16(INK4a), RASSF1A, APC, GSTP1, and RIZ1 genes were significantly greater in tumorous versus non-tumorous tissues. Methylation of RIZ1 in non-tumorous tissues was significantly associated with time to recurrence. Additionally, genomic DNA was significantly more hypomethylated in tumorous tissues, and this change was associated with shorter recurrence, but not with clinicopathological features. In conclusion, this study supports the role of aberrant methylation in the pathobiology of HCV-positive HCCs. The finding that RIZ1 methylation and increased levels of LINE-1 hypomethylation in non-tumorous tissues are associated with time to recurrence underscores the importance of assessing the epigenetic state of the liver remnant

Ferroportin and hepcidin: a new hope in diagnosis, prognosis, and therapy for breast cancer

Breast cancer is the most prevalent malignancy in women. The success of breast cancer treatment relies on the ability to detect the disease and correct molecular abnormalities at an early stage of disease development. A recent article describes a marked decrease in the levels of ferroportin in breast cancer. More importantly, the presented results demonstrate convincingly the incredible diagnostic and prognostic value of ferroportin and hepcidin gene expression in breast cancer and suggest that determination of these two molecular markers may be used as guidance toward individualized therapy for breast cancer patients

Progress in identifying epigenetic mechanisms of xenobiotic-induced non-genotoxic carcinogenesis

Determining the human relevance of structurally and functionally distinct non-genotoxic carcinogenic compounds that induce a diverse range of tissue-, gender-, strain- and species-specific tumours in animals remains a major challenge for toxicologists. Nevertheless, elucidating mechanisms of xenobiotic-induced tumours in animals can provide industry, environmental and regulatory scientists with valuable tools for cancer hazard identification and risk assessment. The discovery that aberrant epigenetic events frequently accompany genetic mutations in human cancers has stimulated efforts to deploy integrated epigenomic and transcriptomic profiling of xenobiotic-induced non-genotoxic carcinogenesis (NGC) in animal models, enabling enhanced mechanistic interpretation and novel early biomarker discovery. Recent advances in the mapping and functional characterization of mammalian tissue-specific epigenomes also provides new opportunities to characterize the cross-strain/-species chromatin architecture of non-genotoxic carcinogen effector genes and to predict their potential for modulation by xenobiotics in human tissue. Since xenobiotic-induced perturbations of gene regulation are intimately associated with the underlying DNA sequence, there is a need to integrate the impact of genotype on susceptibility to NGC. Furthermore, the potential association of xenobiotic target modulation with tumorigenic phenotypes can be assessed using genetic models and cancer genome resources. Finally, we discuss how epigenomic profiling may be used to critically assess the comparability and validity of cellular NGC models versus in vivo-derived tissue samples and some of key challenges associated with incorporating epigenetic mechanisms and biomarkers into cancer risk assessment

Local iron homeostasis in the breast ductal carcinoma microenvironment

Abstract BACKGROUND: While the deregulation of iron homeostasis in breast epithelial cells is acknowledged, iron-related alterations in stromal inflammatory cells from the tumor microenvironment have not been explored. METHODS: Immunohistochemistry for hepcidin, ferroportin 1 (FPN1), transferrin receptor 1 (TFR1) and ferritin (FT) was performed in primary breast tissues and axillary lymph nodes in order to dissect the iron-profiles of epithelial cells, lymphocytes and macrophages. Furthermore, breast carcinoma core biopsies frozen in optimum cutting temperature (OCT) compound were subjected to imaging flow cytometry to confirm FPN1 expression in the cell types previously evaluated and determine its cellular localization. RESULTS: We confirm previous results by showing that breast cancer epithelial cells present an 'iron-utilization phenotype' with an increased expression of hepcidin and TFR1, and decreased expression of FT. On the other hand, lymphocytes and macrophages infiltrating primary tumors and from metastized lymph nodes display an 'iron-donor' phenotype, with increased expression of FPN1 and FT, concomitant with an activation profile reflected by a higher expression of TFR1 and hepcidin. A higher percentage of breast carcinomas, compared to control mastectomy samples, present iron accumulation in stromal inflammatory cells, suggesting that these cells may constitute an effective tissue iron reservoir. Additionally, not only the deregulated expression of iron-related proteins in epithelial cells, but also on lymphocytes and macrophages, are associated with clinicopathological markers of breast cancer poor prognosis, such as negative hormone receptor status and tumor size. CONCLUSIONS: The present results reinforce the importance of analyzing the tumor microenvironment in breast cancer, extending the contribution of immune cells to local iron homeostasis in the tumor microenvironment context.info:eu-repo/semantics/publishedVersio

Redox cycling metals: Pedaling their roles in metabolism and their use in the development of novel therapeutics

Essential metals, such as iron and copper, play a critical role in a plethora of cellular processes including cell growth and proliferation. However, concomitantly, excess of these metal ions in the body can have deleterious effects due to their ability to generate cytotoxic reactive oxygen species (ROS). Thus, the human body has evolved a very well-orchestrated metabolic system that keeps tight control on the levels of these metal ions. Considering their very high proliferation rate, cancer cells require a high abundance of these metals compared to their normal counterparts. Interestingly, new anti-cancer agents that take advantage of the sensitivity of cancer cells to metal sequestration and their susceptibility to ROS have been developed. These ligands can avidly bind metal ions to form redox active metal complexes, which lead to generation of cytotoxic ROS. Furthermore, these agents also act as potent metastasis suppressors due to their ability to up-regulate the metastasis suppressor gene, N-myc downstream regulated gene 1. This review discusses the importance of iron and copper in the metabolism and progression of cancer, how they can be exploited to target tumors and the clinical translation of novel anti-cancer chemotherapeutics