<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><bold>Background.</bold> Human exposure to genotoxic agents in the environment and everyday life represents a serious health threat. Fast and reliable assessment of genotoxicity of chemicals is of main importance in the fields of new chemicals and drug development as well as in environmental monitoring. The tumor suppressor gene <italic>p21</italic>, the major down-stream target gene of activated <italic>p53</italic> which is responsible for cell cycle arrest following DNA damage, has been shown to be specifically up-regulated by genotoxic carcinogens. The aim of our study was to develop a human cell-based biosensor system for simple and fast detection of genotoxic agents.<bold>Methods.</bold> Metabolically active HepG2 human hepatoma cells were transfected with plasmid encoding Enhanced Green Fluorescent Protein (EGFP) under the control of the <italic>p21</italic> promoter (p21HepG2GFP). DNA damage was induced by genotoxic agents with known mechanisms of action. The increase in fluorescence intensity, due to <italic>p21</italic> mediated EGFP expression, was measured with a fluorescence microplate reader. The viability of treated cells was determined by the colorimetric MTS assay.<bold>Results.</bold> The directly acting alkylating agent methylmethane sulphonate (MMS) showed significant increase in EGFP production after 48 h at 20 μg/mL. The indirectly acting carcinogen benzo(a)pyren (BaP) and the cross-linking agent cisplatin (CisPt) induced a dose- dependent increase in EGFP fluorescence, which was already significant at concentrations 0.13 μg/mL and 0.41 μg/mL, respectively. Vinblastine (VLB), a spindle poison that does not induce direct DNA damage, induced only a small increase in EGFP fluorescence intensity after 24 h at the lowest concentration (0.1 μg/mL), while exposure to higher concentrations was associated with significantly reduced cell viability.<bold>Conclusions.</bold> The results of our study demonstrated that this novel assay based on the stably transformed cell line p21HepG2GFP can be used as a fast and simple biosensor system for detection of genetic damage caused by chemical agents.</abstract>

Background. Human exposure to genotoxic agents in the environment and everyday life represents a serious health threat. Fast and reliable assessment of genotoxicity of chemicals is of main importance in the fields of new chemicals and drug development as well as in environmental monitoring. The tumor suppressor gene p21, the major down-stream target gene of activated p53 which is responsible for cell cycle arrest following DNA damage, has been shown to be specifically up-regulated by genotoxic carcinogens. The aim of our study was to develop a human cell-based biosensor system for simple and fast detection of genotoxic agents.Methods. Metabolically active HepG2 human hepatoma cells were transfected with plasmid encoding Enhanced Green Fluorescent Protein (EGFP) under the control of the p21 promoter (p21HepG2GFP). DNA damage was induced by genotoxic agents with known mechanisms of action. The increase in fluorescence intensity, due to p21 mediated EGFP expression, was measured with a fluorescence microplate reader. The viability of treated cells was determined by the colorimetric MTS assay.Results. The directly acting alkylating agent methylmethane sulphonate (MMS) showed significant increase in EGFP production after 48 h at 20 μg/mL. The indirectly acting carcinogen benzo(a)pyren (BaP) and the cross-linking agent cisplatin (CisPt) induced a dose- dependent increase in EGFP fluorescence, which was already significant at concentrations 0.13 μg/mL and 0.41 μg/mL, respectively. Vinblastine (VLB), a spindle poison that does not induce direct DNA damage, induced only a small increase in EGFP fluorescence intensity after 24 h at the lowest concentration (0.1 μg/mL), while exposure to higher concentrations was associated with significantly reduced cell viability.Conclusions. The results of our study demonstrated that this novel assay based on the stably transformed cell line p21HepG2GFP can be used as a fast and simple biosensor system for detection of genetic damage caused by chemical agents.

Development of human cell biosensor system for genotoxicity detection based on DNA damage-induced gene expression

Department of Radiotherapy and Department of Experimental Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia

Department for Genetic Toxicology and Cancer Biology, National Institute of Biology, Ljubljana, Slovenia

Radiology and Oncology

Background. Human exposure to genotoxic agents in the environment and everyday life represents a serious health threat. Fast and reliable assessment of...

Development of human cell biosensor system for genotoxicity detection based on DNA damage-induced gene expression

Published Online: Mar 18, 2010

Page range: 42 - 51

DOI: https://doi.org/10.2478/v10019-010-0010-3

Keywords
HepG2 cells, biosensor system, green fluorescent protein, reporter gene assay, genotoxicity, p21 promoter

This content is open access.

Development of human cell biosensor system for genotoxicity detection based on DNA damage-induced gene expression

Published Online: Mar 18, 2010

Page range: 42 - 51

DOI: https://doi.org/10.2478/v10019-010-0010-3

KeywordsHepG2 cells, biosensor system, green fluorescent protein, reporter gene assay, genotoxicity, p21 promoter

This content is open access.

Keywords
HepG2 cells, biosensor system, green fluorescent protein, reporter gene assay, genotoxicity, p21 promoter