Tumour-specific amplitude-modulated radiofrequency electromagnetic fields induce differentiation of hepatocellular carcinoma via targeting Ca3.2 T-type voltage-gated calcium channels and Ca influx.

Background: Administration of amplitude modulated 27·12 MHz radiofrequency electromagnetic fields (AM RF EMF) by means of a spoon-shaped applicator placed on the patient's tongue is a newly approved treatment for advanced hepatocellular carcinoma (HCC). The mechanism of action of tumour-specific AM RF EMF is largely unknown.

Methods: Whole body and organ-specific human dosimetry analyses were performed.

Differential Effects of Nano TiO₂ and CeO₂ on Normal Human Lung Epithelial Cells .

Nano-TiO₂ and nano-CeO₂ are among the most widely used engineered nanoparticles (NPs). We investigated a variety of endpoints to assess the toxicity of eight of these NPs to induce potentially adverse health effects in an human respiratory epithelial cell model. These endpoints include cytotoxicity, reactive oxygen species (ROS)/reactive nitrogen species (RNS) production, 8-hydroxy-2_-deoxyguanosine (8-oxo-dG), endogenous DNA adducts, Apurinic/apyrimidinic (AP) sites, 4-Hrdoxynonenal (4-HNE) protein adducts, Malondialdehyde (MDA) protein adducts, and genomics analysis on altered signaling pathways.

Signaling Pathways and MicroRNA Changes in Nano-TiO2 Treated Human Lung Epithelial (BEAS-2B) Cells.

The effect of titanium dioxide nanoparticles (nano-TiO2 Degussa p25) treatment of human lung epithelial cells (BEAS-2B) was examined by analyzing changes in messenger [mRNA] and microRNA [miRNA]. BEAS-2B cells were treated with 0, 3, 10, 30 or 100 μg/ml nano-TiO2 for 1 day (for mRNA analysis) or 3 days (for miRNA analysis). Differentially expressed mRNA and miRNA were analyzed using Affymetrix microarrays and Affymetrix miRNA microarrays, respectively.

Cellular interactions and biological responses to titanium dioxide nanoparticles in HepG2 and BEAS-2B cells: role of cell culture media.

We showed previously that exposure of human lung cells (BEAS-2B) to TiO2 nanoparticles (nano-TiO2 ) produced micronuclei (MN) only when the final concentration of protein in the cell-culture medium was at least 1%. Nanoparticles localize in the liver; thus, we exposed human liver cells (HepG2) to nano-TiO2 and found the same requirement for MN induction. Nano-TiO2 also formed small agglomerates in medium containing as little as 1% protein and caused cellular interaction as measured by side scatter by flow cytometry and DNA damage (comet assay) in HepG2 cells.

Investigating oxidative stress and inflammatory responses elicited by silver nanoparticles using high-throughput reporter genes in HepG2 cells: effect of size, surface coating, and intracellular uptake.

Silver nanoparticles (Ag NP) have been shown to generate reactive oxygen species; however, the association between physicochemical characteristics of nanoparticles and cellular stress responses elicited by exposure has not been elucidated. Here, we examined three key stress-responsive pathways activated by Nrf-2/ARE, NFκB, and AP1 during exposure to Ag NP of two distinct sizes (10 and 75 nm) and coatings (citrate and polyvinylpyrrolidone), as well as silver nitrate (AgNO3), and CeO2 nanoparticles. The in vitro assays assessed the cellular response in a battery of stable luciferase-reporter HepG2 cell lines.

Effect of treatment media on the agglomeration of titanium dioxide nanoparticles: impact on genotoxicity, cellular interaction, and cell cycle.

The widespread use of titanium dioxide (TiO2) nanoparticles in consumer products increases the probability of exposure to humans and the environment. Although TiO2 nanoparticles have been shown to induce DNA damage (comet assay) and chromosome damage (micronucleus assay, MN) in vitro, no study has systematically assessed the influence of medium composition on the physicochemical characteristics and genotoxicity of TiO2 nanoparticles. We assessed TiO2 nanoparticle agglomeration, cellular interaction, induction of genotoxicity, and influence on cell cycle in human lung epithelial cells using three different nanoparticle-treatment media: keratinocyte growth medium (KGM) plus 0.

Macrophages under low oxygen culture conditions respond to ion parametric resonance magnetic fields - biomed 2011.

Macrophages, when entering inflamed tissue, encounter low oxygen tension due to the impairment of blood supply and/or the massive infiltration of cells that consume oxygen. Previously, we showed that such macrophages release more bacteriotoxic hydrogen peroxide (H2O2) when exposed in vitro to low oxygen than when cultured at usual ambient oxygen conditions. In this study, we use this low-oxygen, inflammatory macrophage model to test the macrophages’ response to low-frequency magnetic fields.

Chloral hydrate decreases gap junction communication in rat liver epithelial cells.

Gap junction communication (GJC) is involved in controlling cell proliferation and differentiation. Alterations in GJC are associated with carcinogenesis, but the mechanisms involved are unknown. Chloral hydrate (CH), a by-product of chlorine disinfection of water, is carcinogenic in mice, and we demonstrated that CH reduced GJC in a rat liver epithelial cell line (Clone 9).

A potential microRNA signature for tumorigenic conazoles in mouse liver.

Triadimefon, propiconazole, and myclobutanil are conazoles, an important class of agricultural fungicides. Triadimefon and propiconazole are mouse liver tumorigens, while myclobutanil is not. As part of a coordinated study to understand the molecular determinants of conazole tumorigenicity, we analyzed the microRNA expression levels in control and conazole-treated mice after 90 d of administration in feed.

Can EMF exposure during development leave an imprint later in life?

People in industrialized nations live in an environment of ubiquitous electromagnetic field (EMF) exposure, both natural and anthropogenic. The intensity, variety, and geographic distribution of anthropogenic EMF exposures have grown dramatically since the mid 20th century, with many uses serving, and in close proximity to, human populations, such as electric power distribution, radio and television transmission, and more recently, personal cell phone communication units and transmitting towers. Thus, it is reasonable to ask if this EMF exposure could cause alterations in the physiology of developing organisms, since they are generally assumed to be the most sensitive to chemical stressors.