The Efficiency of Translesion Synthesis Past Single Styrene Oxide DNA Adducts in Vitro Is Polymerase-Specific

Alcohol consumption is a risk factor for the development of several cancers, including those of the head and neck and the esophagus. The underlying mechanisms of alcohol-induced carcinogenesis remain unclear; however, at these sites, alcohol-derived acetaldehyde seems to play a major role. By reacting with DNA, acetaldehyde generates covalent modifications (adducts) that can lead to mutations. Previous studies have shown a dose dependence between levels of a major acetaldehyde-derived DNA adduct and alcohol exposure in oral-cell DNA. The goal of this study was to optimize a mass spectrometry (MS)-based DNA adductomic approach to screen for all acetaldehyde-derived DNA adducts to more comprehensively characterize the genotoxic effects of acetaldehyde in humans. A high-resolution/-accurate-mass data-dependent constant-neutral-loss-MS3 methodology was developed to profile acetaldehyde-DNA adducts in purified DNA. This resulted in the identification of 22 DNA adducts. In addition to the expected N2-ethyldeoxyguanosine (after NaBH3CN reduction), two previously unreported adducts showed prominent signals in the mass spectra. MSn fragmentation spectra and accurate mass were used to hypothesize the structure of the two new adducts, which were then identified as N6-ethyldeoxyadenosine and N4-ethyldeoxycytidine by comparison with synthesized standards. These adducts were quantified in DNA isolated from oral cells collected from volunteers exposed to alcohol, revealing a significant increase after the exposure. In addition, 17 of the adducts identified in vitro were detected in these samples confirming our ability to more comprehensively characterize the DNA damage deriving from alcohol exposures.

Download Full-text

Synthesis andin vitroAntitumor Potency of (Cyclohexane-1,2-Diamine)Platinum(II) Complexes with Aminotris(Methylenephosphonic Acid) as Bone-Seeking Ligand

Bioinorganic Chemistry and Applications ◽

10.1155/bca.2005.179 ◽

2005 ◽

Vol 3 (3-4) ◽

pp. 179-190 ◽

Cited By ~ 5

Author(s):

Markus Galanski ◽

Susanna Slaby ◽

Michael A. Jakupec ◽

Bernhard K. Keppler

Keyword(s):

Dna Adducts ◽

Coordination Mode ◽

Carcinoma Cell ◽

Platinum Complexes ◽

Ovarian Carcinoma Cell Line ◽

Aminoacetic Acid ◽

Structure Activity ◽

Cellular Processing ◽

Diamine Ligands

In order to develop platinum complexes with selective activity in primary and secondary bone malignancies and with the aim to optimize antitumor activity, platinum(II) complexes with aminotris(methylenephosphonic acid) as bone-seeking (osteotropic) ligand have been synthesized, characterized and tested in the cisplatin-sensitive ovarian carcinoma cell line CH1. As non-leaving diamine ligands, which are decisive for the cellular processing of DNA adducts,cis-R,S-cyclohexane-1,2-diamine,trans-S,S-cyclohexane-1,2-diamine andtrans-R,R-cyclohexane-1,2-diamine have been used, resulting in complexes 1, 2, and 3, respectively. The cytotoxicity of the complexes under investigation decreases in the order 3>2>1 which is in accord with structure-activity relationships with other (cyclohexane-1,2- diamine)platinum(II) and platinum(IV) complexes: Bothtranscomplexes (2 and 3) display a higherin vitropotency than the correspondingcisisomer (I), with thetrans-R,Risomer (3) being the most active in this series. In comparison to the analogous (cyclohexane-1,2-diamine)platinum(II) complexes with bis(phosphonomethyl)aminoacetic acid as osteotropic carrier ligand, the cytotoxicity of 1-3 was found to be 1.5 – 2 fold higher, which is explainable by a different coordination mode of the phosphonic acid ligands (acetato versus phosphonato).

Download Full-text

In Vitro Characterization of DNA Adducts Formed by Foundry Air Particulate Matter

Environmental Health Perspectives ◽

10.2307/3432846 ◽

1996 ◽

Vol 104 ◽

pp. 687 ◽

Cited By ~ 1

Author(s):

K. Savela ◽

M. J. Kohan ◽

D. Walsh ◽

F. P. Perera ◽

K. Hemminki ◽

...

Keyword(s):

Particulate Matter ◽

Dna Adducts ◽

Air Particulate Matter ◽

Air Particulate ◽

In Vitro Characterization

Download Full-text

Deoxynucleotide polymerization by HIV-1 reverse transcriptase is terminated by site-specific styrene oxide adducts after translesion synthesis.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)61933-2 ◽

1994 ◽

Vol 269 (46) ◽

pp. 28527-28530

Author(s):

G.J. Latham ◽

R.S. Lloyd

Keyword(s):

Reverse Transcriptase ◽

Styrene Oxide ◽

Translesion Synthesis ◽

Site Specific ◽

Hiv 1

Download Full-text

Replication Past the -Radiation-Induced Guanine-Thymine Cross-Link G[8,5-Me]T by Human and Yeast DNA Polymerase

Journal of Nucleic Acids ◽

10.4061/2010/101495 ◽

2010 ◽

Vol 2010 ◽

pp. 1-10 ◽

Cited By ~ 4

Author(s):

Paromita Raychaudhury ◽

Ashis K. Basu

Keyword(s):

Dna Polymerase ◽

Mammalian Cells ◽

Translesion Synthesis ◽

Kidney Cells ◽

Equal Frequency ◽

Cross Link ◽

Dominant Mutation ◽

Human Embryonic Kidney Cells ◽

Radiation Induced

-Radiation-induced intrastrand guanine-thymine cross-link, G[8,5-Me]T, hinders replicationin vitroand is mutagenic in mammalian cells. Herein we reportin vitrotranslesion synthesis of G[8,5-Me]T by human and yeast DNA polymerase (hPol and yPol ). dAMP misincorporation opposite the cross-linked G by yPol was preferred over correct incorporation of dCMP, but further extension was 100-fold less efficient for :A compared to :C. For hPol , both incorporation and extension were more efficient with the correct nucleotides. To evaluate translesion synthesis in the presence of all four dNTPs, we have developed a plasmid-based DNA sequencing assay, which showed that yPol was more error-prone. Mutational frequencies of yPol and hPol were 36% and 14%, respectively. Targeted was the dominant mutation by both DNA polymerases. But yPol induced targeted in 23% frequency relative to 4% by hPol . For yPol , targeted and constituted 83% of the mutations. By contrast, with hPol , semi-targeted mutations (7.2%), that is, mutations at bases near the lesion, occurred at equal frequency as the targeted mutations (6.9%). The kind of mutations detected with hPol showed significant similarities with the mutational spectrum of G[8,5-Me]T in human embryonic kidney cells.

Download Full-text