Detection and quantification of 4-ABP adducts in DNA from bladder cancer patients.
We analyzed bladder DNA from 27 cancer patients for dG-C8-4-aminobiphenyl (dG-C8-ABP) adducts using the liquid chromatography tandem mass spectrometry method with a 700 attomol (1 adduct in 10(9) bases) detection limit. Hemoglobin (Hb) 4-aminobiphenyl (4-ABP) adduct levels were measured by gas chromatography-mass spectrometry. After isolation of dG-C8-ABP by immunoaffinity chromatography and further purification, deuterated (d9) dG-C8-ABP (MW=443 Da) was added to each sample. Structural evidence and adduct quantification were determined by selected reaction monitoring, based on the expected adduct ion [M+H+]+1, at m/z 435 with fragmentation to the product ion at m/z 319, and monitoring of the transition for the internal standard, m/z 444-->328. The method was validated by analysis of DNA (100 microg each) from calf thymus; livers from ABP-treated and untreated rats; human placentas; and TK6 lymphoblastoid cells. Adduct was detected at femtomol levels in DNA from livers of ABP-treated rats and calf thymus, but not in other controls. The method was applied to 41 DNA samples (200 microg each) from 27 human bladders; 28 from tumor and 14 from surrounding non-tumor tissue. Of 27 tissues analyzed, 44% (12) contained 5-80 dG-C8-ABP adducts per 10(9) bases; only 1 out of 27 (4%) contained adduct in both tumor and surrounding tissues. The Hb adduct was detected in samples from all patients, at levels of 12-1960 pg per gram Hb. There was no correlation between levels of DNA and Hb adducts. The presence of DNA adducts in 44% of the subjects and high levels of Hb adducts in these non-smokers indicate environmental sources of exposure to 4-ABP.
Zayas
Beatriz
B
Universidad Metropolitana, San Juan, Puerto Rico.
Stillwell
Sara W
SW
Wishnok
John S
JS
Trudel
Laura J
LJ
Skipper
Paul
P
Yu
Mimi C
MC
Tannenbaum
Steven R
SR
Wogan
Gerald N
GN
D000611:Aminobiphenyl Compounds / Q000737:chemistry*; D000818:Animals; D002846:Chromatography, Affinity; D002853:Chromatography, Liquid; D018736:DNA Adducts / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D013058:Mass Spectrometry; D051381:Rats; D011916:Rats, Inbred F344; D013552:Swine; D014026:Nicotiana; D001743:Urinary Bladder / Q000737:chemistry; D001749:Urinary Bladder Neoplasms / Q000737:chemistry*
D000611:Aminobiphenyl Compounds; D018736:DNA Adducts; C006757:4-biphenylamine