Immunoaffinity purification combined with 32P-postlabelling for the detection of O6-methylguanine in DNA from human tissues

Cooper, Donald P.; Griffin, Kathryn A.; Povey, Andrew C.

doi:10.1093/carcin/13.3.469

Cited by 19 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies measuring O 6 -alkylguanines in DNA from human tissues used analytic methods that did not give information about the exact chemical nature of the O 6 -alkylguanine detected (30)(31)(32)(33). In the present study, we used a highly sensitive and specific HRGC-NICI-SIR method that detects four different O 6 -alkylguanines.…”

Section: Discussionmentioning

confidence: 99%

O⁶-Alkylguanines, Dietary N-Nitroso Compounds, and Their Precursors in Gastric Cancer

Palli¹,

Saieva²,

Coppi³

et al. 2001

Nutrition and Cancer

View full text Add to dashboard Cite

Several N-nitroso compounds, present in foods and beverages or formed in the stomach from their precursors, act as alkylating agents. By using a highly reliable technique (high-resolution gas chromatography-mass spectrometry with negative-ion chemical ionization and selected ion recording), we measured a series of specific O6-alkylguanines in snap-frozen paired stomach tissue samples (tumor and noninvolved mucosa) obtained at surgery from 24 gastric cancer patients identified in Florence, Italy. Samples of noninvolved mucosa had higher levels of total O6-alkylguanines and more frequently detectable levels (54%) than tumor samples (29.2%). O6-propylguanine and O6-methylguanine were the single adducts most frequently detected in noninvolved mucosa and tumor tissue, respectively. Tumor samples showed higher levels of total O6-alkylguanines in female patients (p = 0.03) and among those with a diffuse histological type (p = 0.06) or seronegative for Helicobacter pylori CagA antibodies (p = 0.06). Mean dietary nitrate intake was significantly higher in patients with detectable levels of adducts in tumor samples (p = 0.03). Estimated intakes of dimethylamine and N-nitrosodimethylamine correlated with total levels of O6-alkylguanines in noninvolved gastric mucosa. These findings, although based on a small series of cases, support a role for N-nitroso compounds from dietary sources in the etiology of gastric cancer.

show abstract

Section: Discussionmentioning

confidence: 99%

O⁶-Alkylguanines, Dietary N-Nitroso Compounds, and Their Precursors in Gastric Cancer

Palli¹,

Saieva²,

Coppi³

et al. 2001

Nutrition and Cancer

View full text Add to dashboard Cite

show abstract

“…In contrast, from surgical specimens it is sometimes possible to have 1-2 mg DNA, which makes the limit of sensitivity -0.1 fmol Oh-meG per pg DNA. In order to reach maximum sensitivity, 100-1.000 pg of DNA is often used in this method [Wild, 19901. Among the other methods reported, the most sensitive (and also complicated) are those employing a combination of HPLC, "P-postlabelling, and immunopurification [Cooper et al, 1992;Kang et al, 19921. The detection limit reported by Kang et al [1992] was 1 fmol of 06-meG by using 150 k g of DNA.…”

Section: Discussionmentioning

confidence: 99%

Assay by inhibition of repair to measure O⁶‐methylguanine in DNA

Mironov

Martel‐Planche

Wild

1994

Environ and Mol Mutagen

View full text Add to dashboard Cite

A procedure for measuring the level of O6-methylguanine (O6-meG) in DNA is described. Repair of 32P-oligodeoxynucleotides containing O6-meG adducts by O6-alkylguanine alkyltransferase (AGT) was performed in the presence of different quantities of DNA containing unknown concentrations of O6-meG. Each methylated DNA sample inhibited the repair of oligodeoxynucleotide substrate to an extent dependent upon O6-meG concentration. Each DNA sample tested at different concentrations in the assay therefore had a characteristic inhibition curve and could be compared to the curves generated using reference DNA samples of known O6-meG concentration. We report the method of calculation of the O6-meG level in a given DNA sample by comparison of its inhibition curve with that of reference DNAs. This method of calculation does not require a knowledge of the exact quantity of the labelled substrate or AGT used. The method requires only 0.1-10 micrograms of DNA, with a limit of detection of 0.8 fmol of O6-meG per microgram of DNA.

show abstract

“…Aflatoxin exposure dosimetry has been accomplished by combining IAC with HPLC and UV absorbance (A362) to detect adducts in human urine and tissues (28,102,103). In other studies IAC has been combined with 32P-postlabeling and TLC to detect 06 me-dG (104).…”

Section: Combinations Of Methodsmentioning

confidence: 99%

Human DNA adduct measurements: state of the art.

Poirier

Weston

1996

Environ Health Perspect

View full text Add to dashboard Cite

Human DNA adduct formation (covalent modification of DNA with chemical carcinogens) is a promising biomarker for elucidating the molecular epidemiology of cancer. Classes of compounds for which human DNA adducts have been observed include polycyclic aromatic hydrocarbons (PAHs), nitrosamines, mycotoxins, aromatic amines, heterocyclic amines, ultraviolet light, and alkylating cancer chemotherapeutic agents. Most human DNA adduct exposure monitoring has been performed with either 32P-postlabeling or immunoassays, neither of which is able to chemically characterize specific DNA adducts. Recently developed combinations of methods with chemical and physical end points have allowed identification of specific adducts in human tissues. Studies are presented that demonstrate that high ambient levels of benzo[a]pyrene are associated with high levels of DNA adducts in human blood cell DNA and that the same DNA adduct levels drop when the ambient PAH levels decrease significantly. DNA adduct dosimetry, which has been achieved with some dietary carcinogens and cancer chemotherapeutic agents, is described, as well as studies correlating DNA adducts with other biomarkers. It is likely that some toxic, noncarcinogenic compounds may have genotoxic effects, including oxidative damage, and that adverse health outcomes other than cancer may be correlated with DNA adduct formation. The studies presented here may serve as useful prototypes for exploration of other toxicological end points.

show abstract

Immunoaffinity purification combined with ³²P-postlabelling for the detection of O⁶-methylguanine in DNA from human tissues

Cited by 19 publications

References 0 publications

O⁶-Alkylguanines, Dietary N-Nitroso Compounds, and Their Precursors in Gastric Cancer

O⁶-Alkylguanines, Dietary N-Nitroso Compounds, and Their Precursors in Gastric Cancer

Assay by inhibition of repair to measure O⁶‐methylguanine in DNA

Human DNA adduct measurements: state of the art.

Contact Info

Product

Resources

About

Immunoaffinity purification combined with 32P-postlabelling for the detection of O6-methylguanine in DNA from human tissues

Cited by 19 publications

References 0 publications

O6-Alkylguanines, Dietary N-Nitroso Compounds, and Their Precursors in Gastric Cancer

O6-Alkylguanines, Dietary N-Nitroso Compounds, and Their Precursors in Gastric Cancer

Assay by inhibition of repair to measure O6‐methylguanine in DNA

Human DNA adduct measurements: state of the art.

Contact Info

Product

Resources

About

Immunoaffinity purification combined with ³²P-postlabelling for the detection of O⁶-methylguanine in DNA from human tissues

O⁶-Alkylguanines, Dietary N-Nitroso Compounds, and Their Precursors in Gastric Cancer

O⁶-Alkylguanines, Dietary N-Nitroso Compounds, and Their Precursors in Gastric Cancer

Assay by inhibition of repair to measure O⁶‐methylguanine in DNA