Read by QxMD icon Read

Radiation effects on dna

Irina N Vasilyeva, Valery N Zinkin, Vladimir G Bespalov
Exposure to either to low-frequency noise or ionizing radiation causes an increase in the number of chromosomal aberrations in the bone marrow cells and the level of low-molecular-weight DNA in the blood plasma of experimental animals. The dynamics of the content of low-molecular-weight DNA increasing after exposure to low-frequency noise and ionizing radiation differs significantly. Both exposures are able to provide a direct damaging effect on DNA.
2016: Advances in Experimental Medicine and Biology
Stephen O Evans, Michael B Jameson, Ray T M Cursons, Linda M Peters, Steve Bird, Gregory M Jacobson
DNA damage quantitation assays such as the comet assay have focused on the measurement of total nuclear damage per cell. The adoption of PCR-based techniques to quantify DNA damage has enabled sequence- and organelle-specific assessment of DNA lesions. Here we report on an adaptation of a qPCR technique to assess DNA damage in nuclear and mitochondrial targets relative to control. Novel aspects of this assay include application of the assay to the Rotor-Gene platform with optimized DNA polymerase/fluorophore/primer set combination in a touchdown PCR protocol...
October 8, 2016: Biology
Tosol Yu, Bong Jun Cho, Eun Jung Choi, Ji Min Park, Dan Hyo Kim, In Ah Kim
Trastuzumab has been widely used for the treatment of human epidermal growth factor receptor 2 (HER2)-overexpressing breast cancer, however, it cannot easily cross the blood-brain barrier (BBB) and is known to increase the incidence of brain metastases. In contrast, lapatinib has a low molecular weight and can cross the BBB and it could be useful to treat brain metastases in patients with HER2-positive breast cancer.To explore the impact of lapatinib on radiation response, we conducted an in vitro experiment using SKBR3 and BT474 breast carcinoma cells exhibiting HER2/neu amplification...
October 12, 2016: Oncotarget
Neelam Pandey, Sarbani Giri, Samrat Das, Puja Upadhaya
Even though there are contradictory reports regarding the cellular and molecular changes induced by mobile phone emitted radiofrequency radiation (RFR), the possibility of any biological effect cannot be ruled out. In view of a widespread and extensive use of mobile phones, this study evaluates alterations in male germ cell transformation kinetics following RFR exposure and after recovery. Swiss albino mice were exposed to RFR (900 MHz) for 4 h and 8 h duration per day for 35 days. One group of animals was terminated after the exposure period, while others were kept for an additional 35 days post-exposure...
October 13, 2016: Toxicology and Industrial Health
Yuichiro Matsuoka, Hideki Nakayama, Ryoji Yoshida, Akiyuki Hirosue, Masashi Nagata, Takuya Tanaka, Kenta Kawahara, Junki Sakata, Hidetaka Arita, Hikaru Nakashima, Satoru Shinriki, Daiki Fukuma, Hidenao Ogi, Akimitsu Hiraki, Masanori Shinohara, Ryo Toya, Ryuji Murakami
BACKGROUND: In promoting tumour malignancy IL-6 signalling is considered to have an important role. However, the biological roles of IL-6 on radiosensitivity in oral squamous cell carcinoma (OSCC) remain largely unclear. The objective of this study is to determine the effects and molecular mechanisms of IL-6 on radiosensitivity in OSCC. METHODS: Two OSCC cell lines, and OSCC tissue samples with radioresistant cells were used. We examined the effects of IL-6, or tocilizumab, a humanised anti-human IL-6 receptor antibody, or both on radiosensitivity and DNA damage after X-ray irradiation in vitro...
October 13, 2016: British Journal of Cancer
Michael A Terzidis, Andreea Prisecaru, Zara Molphy, Niall Barron, Antonio Randazzo, Elise Dumont, Marios G Krokidis, Andrew Kellett, Chryssostomos Chatgilialoglu
Herein we report the quantification of purine lesions arising from gamma-radiation sourced hydroxyl radicals (HO(•)) on tertiary dsDNA helical forms of supercoiled (SC), open circular (OC) and linear (L) conformation, along with single-stranded folded and non-folded sequences of guanine rich DNA in selected G-quadruplex structures. We identify that DNA helical topology and folding plays major, and unexpected, roles in the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) and 8-oxo-7,8-dihydro-2'-deoxyadenosine (8-oxo-dA), along with tandem-type purine lesions 5',8-cyclo-2'-deoxyguanosine (5',8-cdG) and 5',8-cyclo-2'-deoxyadenosine (5',8-cdA)...
October 13, 2016: Free Radical Research
Cynthia M Rigby, Srirupa Roy, Gagan Deep, Ruth Guillermo-Lagae, Anil K Jain, Deepanshi Dhar, David J Orlicky, Chapla Agarwal, Rajesh Agarwal
Non-melanoma skin cancers (NMSC) are a growing problem given that solar UVB radiation exposure is increasing most likely due to depletion of the atmospheric ozone layer and lack of adequate sun protection. Better preventive methods are urgently required to reduce UV-caused photodamage and NMSC incidence. Earlier, we have reported that silibinin treatment activates p53 and reduces photodamage and NMSC, both in vitro and in vivo; but whether silibinin exerts its protective effects primarily through p53 remain unknown...
October 11, 2016: Carcinogenesis
Brennan Ashwood, Marvin Pollum, Carlos E Crespo-Hernández
In 2014, two unnatural nucleosides, d5SICS and dNaM, were shown to selectively base pair and replicate with high fidelity in a modified strain of E. coli, thus effectively expanding its genetic alphabet from four to six letters. More recently, a significant reduction in cell proliferation was reported in cells cultured with d5SICS, and putatively with dNaM, upon exposure to brief periods of near-visible radiation. The photosensitizing properties of the lowest-energy excited triplet state of both d5SICS and dNaM were implicated in their cytotoxicity...
October 10, 2016: Chemistry: a European Journal
Katharina Gläser, Martina Rohland, Thomas Kleine-Ostmann, Thorsten Schrader, Helga Stopper, Henning Hintzsche
Exposure to electromagnetic fields in the radiofrequency range is ubiquitous, mainly due to the worldwide use of mobile communication devices. With improving technologies and affordability, the number of cell phone subscriptions continues to increase. Therefore, the potential effect on biological systems at low-intensity radiation levels is of great interest. While a number of studies have been performed to investigate this issue, there has been no consensus reached based on the results. The goal of this study was to elucidate the extent to which cells of the hematopoietic system, particularly human hematopoietic stem cells (HSC), were affected by mobile phone radiation...
October 6, 2016: Radiation Research
S I Zaichkina, A R Dyukina, O M Rozanova, S P Romanchenko, N P Sirota, E A Kuznetsova, N B Simonova, S S Sorokina, D T Zakrzhevskaya, V I Yusupov, V N Bagratishvili
We studied the effect of exposure to helium-neon laser (dose range 0.16-50 mJ/cm(2)) on activation of natural protection reserve in mice using the adaptive response test. DNA comets method revealed a protective response manifested in DNA damage level in whole blood leukocytes of mice and in lymphoid organs by the thymus and spleen weight index; preexposure to laser did not induce the adaptive response. ROS level in the whole blood was assessed by the level of zymosan-induced luminol chemiluminescence. In mice subjected to adaptive laser irradiation in doses of 0...
September 2016: Bulletin of Experimental Biology and Medicine
Iyo Shiraishi, Naoya Shikazono, Masao Suzuki, Kentaro Fujii, Akinari Yokoya
PURPOSE: To clarify whether initial base excision repair processes at clustered DNA damage sites comprising multiple base lesions affect subsequent excision processes via the formation of additional strand breaks by glycosylase and apurinic/apyrimidinic (AP) endonuclease base excision enzymes. MATERIALS AND METHODS: Plasmid DNA (pUC18) as a model DNA molecule was exposed to high-linear-energy-transfer (LET) ionizing radiation (He(2+) or C(6+) ions) or low-LET ionizing radiation (X-rays) under various conditions to produce varied radical-scavenging effects...
October 6, 2016: International Journal of Radiation Biology
Liang Wei, Brian J Leibowitz, Xinwei Wang, Michael Epperly, Joel Greenberger, Lin Zhang, Jian Yu
Radiotherapy causes dose-limiting toxicity and long-term complications in rapidly renewing tissues, including the gastrointestinal tract. Currently, there is no FDA-approved agent for the prevention or treatment of radiation-induced intestinal injury. In this study, we have shown that PD 0332991 (PD), an FDA-approved selective inhibitor of cyclin-dependent kinase 4/6 (CDK4/6), prevents radiation-induced lethal intestinal injury in mice. Treating mice with PD or a structurally distinct CDK4/6 inhibitor prior to radiation blocked proliferation and crypt apoptosis and improved crypt regeneration...
October 4, 2016: Journal of Clinical Investigation
Falin Xu, Qiongdan Bai, Kai Zhou, Li Ma, Jiajia Duan, Fangli Zhuang, Cuicui Xie, Wenli Li, Peng Zou, Changlian Zhu
To investigate the effects of exposure to an 1800 MHz electromagnetic field on cell death and cell proliferation in the developing brain, postnatal day 7 (P7) and P21 healthy Kunming mice were randomly assigned into the experimental and control groups. The experimental groups were exposed to an 1800 MHz electromagnetic field for 8 h daily for three consecutive days. The thymidine analog 5-bromo-2-deoxyuridine (BrdU) was injected intraperitoneally 1 h before each exposure session, and all animals were sacrificed 24 h after the last exposure...
October 3, 2016: Electromagnetic Biology and Medicine
Michael D Sevilla, David Becker, Anil Kumar, Amitava Adhikary
The focus of our laboratory's investigation is to study the direct-type DNA damage mechanisms resulting from γ-ray and ion-beam radiation-induced free radical processes in DNA which lead to molecular damage important to cellular survival. This work compares the results of low LET (γ-) and high LET (ion-beam) radiation to develop a chemical track structure model for ion-beam radiation damage to DNA. Recent studies on protonation states of cytosine cation radicals in the N1-substituted cytosine derivatives in their ground state and 5-methylcytosine cation radicals in ground as well as in excited state are described...
November 2016: Radiation Physics and Chemistry
Changxun Fang, Weisi Chen, Chengxun Li, Xin Jian, Yingzhe Li, Hongmei Lin, Wenxiong Lin
UVB radiation causes cyclobutane pyrimidine dimers (CPDs) to form on the DNA of living organisms. This study found that overexpression of the silicon absorbance gene Lsi1 reduced the accumulation of CPDs in rice, which profited from the reactivation by photolyase. The transcript abundance of deoxyribodipyrimidine photolyase (Os10g0167600) was generally correlated with the silicon content of the rice, and the up-regulation of Os10g0167600 was found to be highest in the UVB-treated Lsi1-overexpressed (Lsi1-OX) rice...
October 3, 2016: Scientific Reports
Nikhil Tyagi, Sanjeev K Srivastava, Sumit Arora, Yousef Omar, Zohaib Mohammad Ijaz, Ahmed Al-Ghadhban, Sachin K Deshmukh, James E Carter, Ajay P Singh, Seema Singh
Sunscreen formulations containing UVB filters, such as Zinc-oxide (ZnO) and titanium-dioxide (TiO2) nanoparticles (NPs) have been developed to limit the exposure of human skin to UV-radiations. Unfortunately, these UVB protective agents have failed in controlling the skin cancer incidence. We recently demonstrated that silver nanoparticles (Ag-NPs) could serve as novel protective agents against UVB-radiations. Here our goal was to perform comparative analysis of direct and indirect UVB-protection efficacy of ZnO-, TiO2- and Ag-NPs...
September 28, 2016: Cancer Letters
Pavel Lobachevsky, Trevor Leong, Patricia Daly, Jai Smith, Nickala Best, Ella R Thompson, Na Li, Ian G Campbell, Roger F Martin, Olga A Martin
A small percentage of cancer radiotherapy patients develop abnormally severe side effects as a consequence of intrinsic radiosensitivity. We analysed the γ-H2AX response to ex-vivo irradiation of peripheral blood lymphocytes (PBL) and plucked eyebrow hair follicles from 16 patients who developed severe late radiation toxicity following radiotherapy, and 12 matched control patients. Longer retention of the γ-H2AX signal and lower colocalization efficiency of repair factors in over-responding patients confirmed that DNA repair in these individuals was compromised...
September 28, 2016: Cancer Letters
Mohsen Cheki, Alireza Shirazi, Aziz Mahmoudzadeh, Javad Tavakkoly Bazzaz, Seyed Jalal Hosseinimehr
Metformin is a widely prescribed drug used in the treatment of patients with type 2 diabetes. In this study, the radioprotective effect of metformin was investigated against cytotoxicity and genotoxicity induced by ionizing radiation (IR) in human peripheral blood lymphocytes. Human lymphocytes were treated with metformin at concentrations 10 and 50μM for 2h and irradiated with 6MV X-rays. The radiation antagonistic potential of metformin was assessed by MTT [3-(4,5-dimethyl-2-thiaozolyl)-2,5-diphenyl-2H tetrazolium bromide] assay, chromosomal aberration (CA) analysis, cytokinesis blocked micronucleus (CBMN) assay, and flow cytometry...
October 2016: Mutation Research
Kathleen A Bridges, Xingxing Chen, Huifeng Liu, Crosby Rock, Thomas A Buchholz, Stuart D Shumway, Heath D Skinner, Raymond E Meyn
Radiotherapy is commonly used to treat a variety of solid tumors but improvements in the therapeutic ratio are sorely needed. The aim of this study was to assess the Chk1 kinase inhibitor, MK-8776, for its ability to radiosensitize human tumor cells. Cells derived from NSCLC and HNSCC cancers were tested for radiosensitization by MK-8776. The ability of MK-8776 to abrogate the radiation-induced G2 block was determined using flow cytometry. Effects on repair of radiation-induced DNA double strand breaks (DSBs) were determined on the basis of rad51, γ-H2AX and 53BP1 foci...
September 28, 2016: Oncotarget
Cong Liu, Yuhui Hao, Jiawei Huang, Hong Li, Zhangyou Yang, Yiping Zeng, Jing Liu, Rong Li
Impaired wound healing caused by radiation happens frequently in clinical practice and the exact mechanisms remain partly unclear. Various countermeasures have been taken to tackle with this issue. Ghrelin was considered as a potent endogenous growth hormone releasing peptide, its role in enhancing wound repair and regeneration was firstly investigated in whole body irradiated (γ ray) mice in this study. Collagen deposition and neovascularization were mostly discussed. The results demonstrated that ghrelin administration promoted cutaneous wound healing in irradiated mice, followed with reduced average wound closure time, increased spleen index (SI), and improved hematopoiesis...
September 27, 2016: Experimental Dermatology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"