ABSTRACT
In the present study, the protein microarray was used to investigate the protein expression in human B-cell lymphoblastoid cells intermittently exposed to 1.8-GHz GSM radiofrequency radiation (RFR) at the specific absorption rate (SAR) of 2.0 W/kg for 24 h. The differential expression of 27 proteins was found, which were related to DNA damage repair, apoptosis, oncogenesis, cell cycle and proliferation (ratio >1.5-fold, P<0.05). The results validated with Western blot assay indicated that the expression of RPA32 was significantly down-regulated (P<0.05) while the expression of p73 was significantly up-regulated in RFR exposure group (P<0.05). Because of the crucial roles of those proteins in DNA repair and cell apoptosis, the results of present investigation may explain the biological effects of RFR on DNA damage/repair and cell apoptosis.
Subject(s)
Precursor Cells, B-Lymphoid/metabolism , Precursor Cells, B-Lymphoid/radiation effects , Proteins/metabolism , Proteins/radiation effects , Radio Waves/adverse effects , Apoptosis/radiation effects , Cell Cycle/radiation effects , Cell Line , Cell Proliferation/radiation effects , Cell Transformation, Neoplastic/radiation effects , DNA Repair/radiation effects , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/radiation effects , Down-Regulation/radiation effects , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/radiation effects , Nuclear Proteins/metabolism , Nuclear Proteins/radiation effects , Protein Array Analysis , Replication Protein A/metabolism , Replication Protein A/radiation effects , Tumor Protein p73 , Tumor Suppressor Proteins/metabolism , Tumor Suppressor Proteins/radiation effects , Up-Regulation/radiation effectsABSTRACT
The purpose of present investigation was to compare the cyto-genotoxicity induced by five dental alloys in vitro. The cyto-genotoxicity induced by five dental alloy extracts on human B lymphoblast cells was assessed with neutral red uptake (NRU) , CCK-8, comet and micronucleus (CBMN) assays in vitro, respectively. The results of in vitro comet and CBMN assays indicated that DNA damage (% tail DNA) and micronucleus frequencies (MNFs) in all exposure groups did not significantly increase, as compared with the control group. However, the results of NRU and CCK-8 assays demonstrated that there were to some extent differences in the cytotoxicity among 5 dental alloy extracts in vitro. The cytotoxicity may be relevant to the Ni and Be ions released in the alloy extract.
Subject(s)
B-Lymphocytes/drug effects , DNA Damage/drug effects , Dental Alloys/toxicity , Materials Testing , Beryllium/toxicity , Cell Survival/drug effects , Cells, Cultured , Chromium/toxicity , Cobalt/toxicity , Comet Assay , Humans , Micronucleus Tests , Nickel/toxicityABSTRACT
In the present in vitro study, a comet assay was used to determine whether 1.8-GHz radiofrequency radiation (RFR, SAR of 2W/kg) can influence DNA repair in human B-cell lymphoblastoid cells exposed to doxorubicin (DOX) at the doses of 0microg/ml, 0.05microg/ml, 0.075microg/ml, 0.10microg/ml, 0.15microg/ml and 0.20microg/ml. The combinative exposures to RFR with DOX were divided into five categories. DNA damage was detected at 0h, 6h, 12h, 18h and 24h after exposure to DOX via the comet assay, and the percent of DNA in the tail (% tail DNA) served as the indicator of DNA damage. The results demonstrated that (1) RFR could not directly induce DNA damage of human B-cell lymphoblastoid cells; (2) DOX could significantly induce DNA damage of human B-cell lymphoblastoid cells with the dose-effect relationship, and there were special repair characteristics of DNA damage induced by DOX; (3) E-E-E type (exposure to RFR for 2h, then simultaneous exposure to RFR and DOX, and exposure to RFR for 6h, 12h, 18h and 24h after exposure to DOX) combinative exposure could obviously influence DNA repair at 6h and 12h after exposure to DOX for four DOX doses (0.075microg/ml, 0.10microg/ml, 0.15microg/ml and 0.20microg/ml) in human B-cell lymphoblastoid cells.
Subject(s)
Antibiotics, Antineoplastic/toxicity , B-Lymphocytes/drug effects , B-Lymphocytes/radiation effects , DNA Damage , DNA Repair/physiology , Doxorubicin/toxicity , Radio Waves , Cells, Cultured , Comet Assay , Dose-Response Relationship, Drug , HumansABSTRACT
In the present study, the in vitro comet assay was used to determine whether 1.8-GHz radiofrequency radiation (RFR) can influence DNA repair in human leukocytes exposed to X-rays. The specific energy absorption rate (SAR) of 2 W/kg (the current European safety limit) was applied. The leukocytes from four young healthy donors were intermittently exposed to RFR for 24 h (fields on for 5 min, fields off for 10 min), and then irradiated with X-rays at doses of 0.25, 0.5, 1.0 and 2.0 Gy. DNA damage to human leukocytes was detected using the comet assay at 0, 15, 45, 90, 150 and 240 min after exposure to X-rays. Using the comet assay, the percent of DNA in the tail (% tail DNA) served as the indicator of DNA damage; the DNA repair percentage (DRP) served as the indicator of the DNA repair speed. The results demonstrated that (1) the DNA repair speeds of human leukocytes after X-ray exposure exhibited individual differences among the four donors; (2) the intermittent exposures of 1.8-GHz RFR at the SAR of 2 W/kg for 24 h did not directly induce DNA damage or exhibit synergistic effects with X-rays on human leukocytes.
Subject(s)
DNA Damage/radiation effects , DNA Repair/radiation effects , Microwaves/adverse effects , X-Rays/adverse effects , Comet Assay , Humans , Leukocytes/ultrastructure , Radiation DosageABSTRACT
Cigarette smoke condensates (CSCs) are complex mixed compounds that contain both direct and indirect mutagens/carcinogens. To detect genotoxicity of CSCs in vitro, a combination of various enzymes (e.g. activation and detoxification enzymes) called S9 is usually added. However, as S9 may induce cytotoxicity in target cells, it is unclear whether the addition of S9 can impact CSC-induced toxicity. Here, differences in cytogenotoxicity between CSCs in the presence or absence of S9 were studied using three in vitro assays (neutral red uptake assay, comet assay, and TCR gene mutation test) in human peripheral lymphocytes, which were exposed to CSCs at doses of 25, 50, 75, 100 and 125 microg/ml for 4 h. Assay results showed that both CSCs + S9 or CSCs - S9 could induce a dose-dependent elevation of cytogenotoxic effects in human lymphocytes with some differences between the two groups. The cytogenotoxicity induced by CSCs - S9 was significantly higher than that induced by CSCs + S9 in all three assays. The comet and NRU assays revealed that a dose-response relationship of cytogenotoxicity induced by CSCs + S9 was less typical than that induced by CSCs - S9, possibly due to specific cytogenotoxic agents in CSCs and enzymes contained in the S9 mixture. Thus, the three in vitro assays used in the present study are suitable for detecting cytogenotoxic effects in human lymphocytes induced by CSCs. Furthermore, the cytogenotoxicity induced by both CSCs + S9 and CSCs - S9 should be measured simultaneously when assessing and comparing the biological activity of different CSCs.
Subject(s)
Mutagens , Tobacco Smoke Pollution/adverse effects , Biotransformation , Comet Assay , DNA Damage , Dose-Response Relationship, Drug , Humans , Lymphocytes , Mutagenicity Tests , Neutral Red , SmokeABSTRACT
In present study, human lymphocytes were exposed to cigarette smoke condensates (CSCs) at the doses of 25, 50, 75, 100 and 125 µg ml(-1) with and without S9, and the cyto-genotoxic effects were detected with CCK-8, cell apoptosis and micronucleus assays. DNA repair kinetics was observed with comet assay. Our results indicated that the cell viability decreased with CSCs doses, the percentages of apoptosis cell and the frequencies of micronuclei increased with CSCs doses, and DNA damage of human lymphocytes induced by CSCs could be basically repaired within 240 min. However, the cytotoxicity induced by CSCs +S9 was significantly lower than that induced by CSCs -S9 in CCK-8 and cell apoptosis assays, and the DNA repair speed in +S9 group was quicker than that in -S9 group. In conclusion, S9 may affect not only the cyto-genotoxicity of CSCs but also the repair process of DNA damage induced by CSCs in lymphocytes.
