High resolution proton nuclear magnetic resonance (1H-NMR) spectroscopy was used to examine the response of the MG-63 osteosarcoma cell line grown in monolayer and as 3-dimensional tumor spheroids to the same low dose (2 Gy) of ionizing radiation. The MG-63 cells and spheroids were irradiated at 24 h of growth ...

The purpose of this study was to investigate radioadaptive response in 4 cell-lines under identical conditions using a colony assay. First, 4 cell-lines (V79, HeLa S3, EMT6 and SCCVII) were exposed to 8 Gy at various intervals after pretreatment with an adapting dose of 50 mGy or without it. Second, ...

In the last 10 years evidence has accumulated on the so-called radiation-induced 'non-targeted effects' and in particular on bystander effects, consisting of damage induction in non-irradiated cells most likely following the release of soluble factors by the irradiated ones. These phenomena were observed for different biological endpoints, both lethal and ...

Clonogenic assay or colony formation assay is an in vitro cell survival assay based on the ability of a single cell to grow into a colony. The colony is defined to consist of at least 50 cells. The assay essentially tests every cell in the population for its ability to ...

Quite recently, it was found that metal wires can effectively guide terahertz radiation. We report in this communication an original planar excitation of surface wave on a single wire transmission line. This configuration is well suited for the design of THz BioMEMS dedicated to cell investigation. We show that we ...

BACKGROUND: Multicellular spheroids, an appropriate in vitro system for simulating 3-D tumor micro-milieu can be used for evaluating and predicting tumor response to therapeutic agents including metabolic inhibitors. However, detailed understanding of the nature, distribution and sensitivity/responses of cellular sub-populations to potential therapeutic agents/strategies is required for using this unique ...

The dose conversion coefficient (DCC) is used to assess the risk due to inhaled radon progeny in the human lung. The present work uses the microdosimetric approach and determines the linear energy transfer in the target cell nuclei. Killing of target cells was also taken into account through an effect-specific ...

At the low doses (and low dose rates) relevant to environmental and occupational radiation exposure (0-50 mSv), which are of practical concern for radiation protection, very few cells in the human organism experience more than one traversal by densely ionising particles in their lifetime, the intervals between the tracks, if ...

Ionising radiation can induce responses within non-exposed neighbouring (bystander) cells, which potentially have important implications on the estimates of risk at environmentally relevant doses. Using human skin fibroblasts (AG1522), a range of methods were used to investigate the nature of the signal(s) arising from the exposed cells. The signal(s) can ...

Both bisphosphonates and radiotherapy are highly effective for the management of bone metastases. Our in vitro study examined the cytotoxic effects resulting from combinations of ibandronate and ionising radiations (RX) in various sequences on breast cancer cells. Single radiation doses were given before, at halftime of, or after acute ibandronate ...

Radiotherapy is an effective approach to treating many types of cancer. Recent progress in radiotherapy technology, such as intensity-modulated radiation therapy (IMRT) and three-dimensional (3D) radiotherapy, allow precise energy transfer to the tumor, which has improved local control rates. However, the emergence of tolerant cells during or after radiotherapy remains ...

Genomic instability (GI) is a hallmark of tumorigenic progression and is observed as delayed genetic damage in the progeny of irradiated and unirradiated bystander cells. The expression of GI can be influenced by genotype, cell type and radiation quality. While several studies have demonstrated the induction of GI by high ...

PURPOSE: To determine the role of single (SSB) and double strand break (DSB) repair in the induction and propagation of radiation-induced instability. MATERIALS AND METHODS: Two defined hamster cell lines with known DNA repair deficiencies in DSB repair (XR-C1) and base excision repair (EM-C11) and the parental wild-type line (CHO-9) ...

AIM: To investigate the prediction value of radiosensitivity of hepatocarcinoma cells for apoptosis and micronucleus assay. METHODS: Clonogenic assay, flow cytometry, and CB micronuclei assay were used to survey the cell survival rate, radiation-induced apoptosis and micronucleus frequency of hepatocarcinoma cell lines SMMC-7721, HL-7702, and HepG2 after being irradiated by ...

PURPOSE: The antimalarial agent, artemisinin, also confers cancer-specific cytotoxic effects by reacting with ferrous iron atoms to form free radicals. Here, we investigated the radiosensitizing effects of dihydroartemisinin on glioma cells and assessed some possible mechanisms for these effects. MATERIALS AND METHODS: U373MG glioma cells treated with various concentrations of ...

Gemcitabine has excellent radiosensitizing properties, as shown in both preclinical and clinical studies. Radiosensitization correlated with the early S-phase block of gemcitabine. In the present study, we investigated the role of TP53 in the radiosensitizing effect of gemcitabine. Isogenic A549 cells differing in TP53 status were treated with gemcitabine during ...

The cellular response to ionizing radiation is not limited to cells irradiated directly but can be demonstrated in neighboring "bystander" populations. The ability of mouse embryonic stem (ES) cells to express a bystander effect and the role of the radioresistance gene Rad9 were tested. Mouse ES cells differing in Rad9 ...

A three-dimensional cell culture model composed of human-hamster hybrid (A(L)) and Chinese hamster ovary (CHO) cells in multicellular clusters was used to investigate low linear energy transfer (LET) radiation-induced bystander genotoxicity. CHO cells were mixed with A(L) cells in a 1:5 ratio and briefly centrifuged to produce a spheroid of ...

Following a significant increase in the number of facilities in the world having and developing low- and high-linear energy transfer (LET) microbeams for experimental radiobiological studies, it is useful and demanding to establish reliable computational models to analyze such experiments. This paper summarizes initial MCNP5 calculations of the basic parameters ...

To characterize the radiation-enhancing effects on human cancer cells and underlying mechanisms of celecoxib, a cyclooxygenase (COX)-2 selective inhibitor, and to ascertain whether its effects are COX-2 dependent. Clonogenic cytotoxicity assays and radiation survival assays after treatment with celecoxib +/- radiation were done on four human cancer cell lines that ...

Caffeine sensitizes cells to ionizing radiation, and this effect is believed to be associated with the disruption of DNA damage-responsive cell cycle checkpoints, which is controlled by ATM. Recent studies suggest that misrejoining of DSBs is one of the underlying mechanisms of AT cell hyper-radiosensitivity. In this study, we investigated ...

We have investigated molecular changes in cultured differentiating human lens epithelial cells exposed to high-energy accelerated iron-ion beams as well as to protons and X rays. In this paper, we present results on the effects of radiation on gene families that include or are related to DNA damage, cell cycle ...

Early stage cervical cancer is treated with surgery or radiation with equivalent results. Radiation is used for curative therapy of locally advanced disease and is combined with additional anti-tumor agents to improve control. We determined the potential role of genistein as a radiosensitizer for cervical cancer cells. Human cervical cell ...

Death-associated protein kinase (DAPK) was originally identified as a positive mediator of interferon-gamma (IFNgamma)-induced apoptosis in cervical cancer cells, and interferons have been reported to enhance radiosensitivity in various types of squamous cell carcinoma. To examine whether DAPK can regulate cancer cell radiosensitivity, we investigated DAPK expression and radiosensitivity in ...

X-ray tomography has been shown to provide insights into the internal structure of whole cells that can't be obtained by any other means. With recent advances in instrumentation and the advent of automated cryogenic sample stages, it has become possible to collect isotropic tomographic data from radiation-sensitive cells and to ...

Travelers on space missions will be exposed to a complex radiation environment that includes protons and heavy charged particles. Since protons are present at much higher levels than are heavy ions, the most likely scenario for cellular radiation exposure will be proton exposure followed by a hit by a heavy ...

Cofilin is an actin-associated protein that belongs to the actin depolymerization factor/cofilin family and is important for regulation of actin dynamics. Cofilin can import actin monomers into the nucleus under certain stress conditions, however the biological effects of nuclear transport are unclear. In this study, we found that over-expression of ...

A central tenet in understanding the biological effects of ionizing radiation has been that the initially affected cells were directly damaged by the radiation. By contrast, evidence has emerged concerning "bystander" responses involving damage to nearby cells that were not themselves directly traversed by the radiation. These long-range effects are ...

The possible effects of radiofrequency (RF) exposure on the genetic material of cells are considered very important since damage to the DNA of somatic cells can be linked to cancer development or cell death whereas damage to germ cells can lead to genetic damage in next and subsequent generations. This ...

Peroxiredoxin I (Prx-I), a key member of the peroxiredoxin family, reduces peroxides and equivalents through the thioredoxin system. Our previous work has shown that expression of Prx-I in mammalian cells increases following ionizing radiation (IR), indicating that Prx-I actively responds to IR-induced reactive oxygen species (ROS) and suggesting that Prx-I ...

De-mountable calcium fluoride micro cells have been developed for use in synchrotron radiation circular dichroism (SRCD) spectroscopy. They have the advantages that they require only very small sample volumes (as low as 1 microliter) and have short path lengths (as small as 2 micrometers). Highly reproducible spectra can be obtained ...

The mechanisms underlying the unequivocal association between ionizing radiation and the development of leukaemia remain unknown. Recent progress in defining sub-cellular events has contributed to our understanding of the production of genetic lesions in irradiated cells but the importance of tissue effects in response to radiation damage has attracted much ...

The aim of this work was to evaluate the effect of stratospheric radiations on neural tumour cells. ADF human glioblastoma cells were hosted on a stratospheric balloon within the 2002 biological experiment campaign of the Italian Space Agency. The flight at an average height of 37 km lasted about 24 ...

PURPOSE: Interleukin-13 receptor-targeted cytotoxin (IL13-PE38) is highly cytotoxic to human glioblastoma (GBM) cells. Although this molecule is being tested in a multicenter Phase III clinical trial (PRECISE Study) in patients with recurrent disease, the activity of IL13-PE38 when combined with radiation therapy has not been investigated. METHODS AND MATERIALS: Cytotoxicity ...

We have developed an integrated light collimating system with a microlens and a pair of slits for extended optical path length absorbance detection in a capillary electrophoresis (CE) microchip. The collimating system is made of the same material as the chip, poly(dimethylsiloxane) (PDMS), and it is integrated into the chip ...

6-Formylpterin (6FP) has the potential to produce singlet oxygen (1O2) under UV-A radiation. In order to apply this potential to anti-cancer photodynamic therapy (PDT), we prepared a novel variant of 6FP, 2-(N,N-dimethylaminomethyleneamino)-6-formyl-3-pivaloylpteridine-4-one (6FP-tBu-DMF), and examined its photodynamic effects on a pancreatic cancer cell line, Panc-1 cells. The study using laser ...

The purpose of this study was to determine the radiosensitivities of 31 human oesophageal squamous cell carcinoma cell lines with a colony-formation assay. A large variation in radiosensitivity existed among 31 cell lines. Such a large variation may partly explain the poor result of radiotherapy for this cancer. One cell ...

Radiation damage incurred by nuclear DNA is well documented and interest is increasing in the properties of 'bystander' factor(s) and their ability to induce radiation-like damage in cells never exposed to radiation. 'Bystander' and direct low-LET radiation effects on the mitochondria, and more particularly the mitochondrial genome are less well ...

Radiation exposure is an important form of environmental carcinogen and has been associated with increased risk of breast cancer. Epigenetic events, especially those involving alterations in the breast stromal microenvironment, may play an important role in radiation-induced carcinogenesis but remain not well understood. We here show that human mammary stromal ...

Homologous recombination can induce tumorigenic sequence rearrangements. Here, we show that persistent hyper-recombination can be induced following exposure to a bifunctional alkylating agent, mitomycin C (MMC), and that the progeny of exposed cells induce a hyper-recombination phenotype in unexposed neighboring cells. Residual damage cannot be the cause of delayed recombination ...

AIM: To investigate the radiation response of various human tumor cells and normal liver cells. METHODS: Cell lines of human hepatoma cells (SMMC-7721), liver cells (L02), melanoma cells (A375) and cervical tumor (HeLa) were irradiated with (60)Co gamma-rays. Cell survive was documented by a colony assay. Chromatid breaks were measured ...

AIM: To enhance the radiosensitivity of human colon cancer cells by docetaxel. METHODS: Immunoliposomal docetaxel was prepared by coupling monoclonal antibody against carcinoembryonic antigen to cyanuric chloride at the PEG terminus of liposome. LoVo adenocarcinoma cell line was treated with immunoliposomal docetaxel or/and irradiation. MTT colorimetric assay was used to ...

PURPOSE: We previously reported that herbimycin A (HMA) alters the mode of cell death of K562 cells induced by radiation and enhanced their radiosensitivity. In the present study, we explored the apoptosis-inducing activity of HMA and the fundamental mechanism via which it regulates radiation-induced cell death. MATERIALS AND METHODS: Chronic ...

Ionising radiation has been an important part of cancer treatment for almost a century, being used in external-beam radiotherapy, brachytherapy, and targeted radionuclide therapy. At the molecular and cellular level, cell killing has been attributed to deposition of energy from the radiation in the DNA within the nucleus, with production ...

PURPOSE: To investigate whether low frequency pulsed magnetic field (PMF) exposures produce alterations in the cell killing induced by ultraviolet C (UVC) radiation. MATERIALS AND METHODS: MCF-7 breast cancer cells of exponentially growing cultures were exposed to PMF (25 Hz, 0.75 mT) and UVC (from 6.6 J/m2 to 59.4 J/m2) ...

Histone deacetylase inhibitors have been shown to induce numerous biologic effects including, altering cell cycle distribution, cytostasis and in certain cases apoptosis. Given their ability to disrupt critical biological processes in cancer cells, these agents are emerging as potential therapeutics for cancer. Recently, it has been identified that histone deacetylase ...

The clonogenic ability (reproductive cell death) of Chinese hamster V79 cells was measured after treatment with X radiation and a newly developed anti-cancer drug, 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)cytosine (ECyd, TAS106). Amplification in the loss of clonogenicity was observed compared to that obtained for cells exposed to X rays alone. Addition of benzyloxycarbonyl-val-ala-asp-fluoromethylketone (Z-VAD-FMK), ...

PURPOSE: To reveal the interaction between beta-Lapachone (beta-lap) and ionizing radiation in causing cell death in RKO human colon adenocarcinoma cells, and to elucidate the potential usefulness of combined beta-lap treatment and radiotherapy for cancer treatment. MATERIALS AND METHODS: The cytotoxicities of various treatments were determined in vitro using clonogenic ...

The DNA double-strand break (DSB) repair capacity of normal human fibroblasts was compared with that of cell lines with different genetic alterations. These cell lines are affected either in non-homologous end-joining (180BR), homology directed repair (C2352, C2395), base excision repair (CS1TAN, 46BR) or signalling (AT3, AT2BE, LFS2675, LFS2800, 95P558). Cellular ...

The present study examines the effects of ionizing radiation in combination with rituximab (RTX), a chimeric human anti-CD20 monoclonal antibody, on proliferation, cell cycle distribution and apoptosis in B-lymphoma RL and Raji cells. Exposure to ionizing radiation (9 Gy) induced cell growth delay and apoptosis in RL cells, whereas Raji ...