Metabolic activation and carcinogen-DNA adduct detection in human larynx

M. Degawa, S.J. Stern, F.P. Guengerich, P.P. Fu, Kenneth Ilett, R.K. Kaderlik, F.F. Kadlubar

    Research output: Contribution to journalArticle

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    Abstract

    Putative carcinogen-DNA adducts in human larynx tissues (n = 25) from smoker and non/ex-smoker patients were examined by P-32-postlabeling and compared with the metabolic activation capacity of larynx microsomes and cytosols from the same tissues. Hydrophobic DNA adducts were evident only in smokers, and chromatographic profiles of the adducts were similar using either the butanol extraction or nuclease P1 enhancement method, which suggested that the adducts may be derived from polycyclic aromatic hydrocarbons but not aromatic amines. Immunoblots of larynx microsomes using anti-cytochrome P450 1A1/1A2, 2C, 3A4, 2E1, and 2A6 antibodies shelved intensities ranging from 1-10% of that typically observed with human liver microsomes. Enzymatic assays of larynx microsomes showed appreciable activity for benzo(a)pyrene hydroxylation (P450 1A1 and 2C) but not for 4-aminobiphenyl N-oxidation (P450 1A2), which indicated that the observed immunoreactivity was for P450 1A1; this represents the highest level of this P450 yet detected in human extrahepatic tissues. Accordingly, total DNA adduct levels in the larynx correlated strongly with levels of P450 2C, 1A1, and 3A4 but not with P450 2E1 or 2A6.Larynx cytosols also showed appreciable aromatic amine N-acetyltransferase activity for p-aminobenzoic acid (NAT-1) but not for sulfamethazine (NAT-2); however, NAT-1 activity was not correlated with total DNA adducts, which is again consistent with the lack of aromatic amine-DNA adducts detected by P-32-postlabeling. Thus, these results suggest that the DNA adducts detected in human larynx are largely derived from metabolic activation of polycyclic aromatic hydrocarbons in cigarette smoke by P450 2C, 3A4, and/or 1A1.
    Original languageEnglish
    Pages (from-to)4915-4919
    JournalCancer Research
    Volume54
    Publication statusPublished - 1994

    Fingerprint

    DNA Adducts
    Larynx
    Carcinogens
    Microsomes
    Polycyclic Aromatic Hydrocarbons
    Cytosol
    Amines
    Sulfamethazine
    4-Aminobenzoic Acid
    Cytochrome P-450 CYP1A2
    Butanols
    Benzo(a)pyrene
    Enzyme Assays
    Liver Microsomes
    Hydroxylation
    Metabolic Activation
    Smoke
    Tobacco Products
    Antibodies
    N-acetyltalosaminuronic acid

    Cite this

    Degawa, M., Stern, S. J., Guengerich, F. P., Fu, P. P., Ilett, K., Kaderlik, R. K., & Kadlubar, F. F. (1994). Metabolic activation and carcinogen-DNA adduct detection in human larynx. Cancer Research, 54, 4915-4919.
    Degawa, M. ; Stern, S.J. ; Guengerich, F.P. ; Fu, P.P. ; Ilett, Kenneth ; Kaderlik, R.K. ; Kadlubar, F.F. / Metabolic activation and carcinogen-DNA adduct detection in human larynx. In: Cancer Research. 1994 ; Vol. 54. pp. 4915-4919.
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    abstract = "Putative carcinogen-DNA adducts in human larynx tissues (n = 25) from smoker and non/ex-smoker patients were examined by P-32-postlabeling and compared with the metabolic activation capacity of larynx microsomes and cytosols from the same tissues. Hydrophobic DNA adducts were evident only in smokers, and chromatographic profiles of the adducts were similar using either the butanol extraction or nuclease P1 enhancement method, which suggested that the adducts may be derived from polycyclic aromatic hydrocarbons but not aromatic amines. Immunoblots of larynx microsomes using anti-cytochrome P450 1A1/1A2, 2C, 3A4, 2E1, and 2A6 antibodies shelved intensities ranging from 1-10{\%} of that typically observed with human liver microsomes. Enzymatic assays of larynx microsomes showed appreciable activity for benzo(a)pyrene hydroxylation (P450 1A1 and 2C) but not for 4-aminobiphenyl N-oxidation (P450 1A2), which indicated that the observed immunoreactivity was for P450 1A1; this represents the highest level of this P450 yet detected in human extrahepatic tissues. Accordingly, total DNA adduct levels in the larynx correlated strongly with levels of P450 2C, 1A1, and 3A4 but not with P450 2E1 or 2A6.Larynx cytosols also showed appreciable aromatic amine N-acetyltransferase activity for p-aminobenzoic acid (NAT-1) but not for sulfamethazine (NAT-2); however, NAT-1 activity was not correlated with total DNA adducts, which is again consistent with the lack of aromatic amine-DNA adducts detected by P-32-postlabeling. Thus, these results suggest that the DNA adducts detected in human larynx are largely derived from metabolic activation of polycyclic aromatic hydrocarbons in cigarette smoke by P450 2C, 3A4, and/or 1A1.",
    author = "M. Degawa and S.J. Stern and F.P. Guengerich and P.P. Fu and Kenneth Ilett and R.K. Kaderlik and F.F. Kadlubar",
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    Degawa, M, Stern, SJ, Guengerich, FP, Fu, PP, Ilett, K, Kaderlik, RK & Kadlubar, FF 1994, 'Metabolic activation and carcinogen-DNA adduct detection in human larynx' Cancer Research, vol. 54, pp. 4915-4919.

    Metabolic activation and carcinogen-DNA adduct detection in human larynx. / Degawa, M.; Stern, S.J.; Guengerich, F.P.; Fu, P.P.; Ilett, Kenneth; Kaderlik, R.K.; Kadlubar, F.F.

    In: Cancer Research, Vol. 54, 1994, p. 4915-4919.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Metabolic activation and carcinogen-DNA adduct detection in human larynx

    AU - Degawa, M.

    AU - Stern, S.J.

    AU - Guengerich, F.P.

    AU - Fu, P.P.

    AU - Ilett, Kenneth

    AU - Kaderlik, R.K.

    AU - Kadlubar, F.F.

    PY - 1994

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    N2 - Putative carcinogen-DNA adducts in human larynx tissues (n = 25) from smoker and non/ex-smoker patients were examined by P-32-postlabeling and compared with the metabolic activation capacity of larynx microsomes and cytosols from the same tissues. Hydrophobic DNA adducts were evident only in smokers, and chromatographic profiles of the adducts were similar using either the butanol extraction or nuclease P1 enhancement method, which suggested that the adducts may be derived from polycyclic aromatic hydrocarbons but not aromatic amines. Immunoblots of larynx microsomes using anti-cytochrome P450 1A1/1A2, 2C, 3A4, 2E1, and 2A6 antibodies shelved intensities ranging from 1-10% of that typically observed with human liver microsomes. Enzymatic assays of larynx microsomes showed appreciable activity for benzo(a)pyrene hydroxylation (P450 1A1 and 2C) but not for 4-aminobiphenyl N-oxidation (P450 1A2), which indicated that the observed immunoreactivity was for P450 1A1; this represents the highest level of this P450 yet detected in human extrahepatic tissues. Accordingly, total DNA adduct levels in the larynx correlated strongly with levels of P450 2C, 1A1, and 3A4 but not with P450 2E1 or 2A6.Larynx cytosols also showed appreciable aromatic amine N-acetyltransferase activity for p-aminobenzoic acid (NAT-1) but not for sulfamethazine (NAT-2); however, NAT-1 activity was not correlated with total DNA adducts, which is again consistent with the lack of aromatic amine-DNA adducts detected by P-32-postlabeling. Thus, these results suggest that the DNA adducts detected in human larynx are largely derived from metabolic activation of polycyclic aromatic hydrocarbons in cigarette smoke by P450 2C, 3A4, and/or 1A1.

    AB - Putative carcinogen-DNA adducts in human larynx tissues (n = 25) from smoker and non/ex-smoker patients were examined by P-32-postlabeling and compared with the metabolic activation capacity of larynx microsomes and cytosols from the same tissues. Hydrophobic DNA adducts were evident only in smokers, and chromatographic profiles of the adducts were similar using either the butanol extraction or nuclease P1 enhancement method, which suggested that the adducts may be derived from polycyclic aromatic hydrocarbons but not aromatic amines. Immunoblots of larynx microsomes using anti-cytochrome P450 1A1/1A2, 2C, 3A4, 2E1, and 2A6 antibodies shelved intensities ranging from 1-10% of that typically observed with human liver microsomes. Enzymatic assays of larynx microsomes showed appreciable activity for benzo(a)pyrene hydroxylation (P450 1A1 and 2C) but not for 4-aminobiphenyl N-oxidation (P450 1A2), which indicated that the observed immunoreactivity was for P450 1A1; this represents the highest level of this P450 yet detected in human extrahepatic tissues. Accordingly, total DNA adduct levels in the larynx correlated strongly with levels of P450 2C, 1A1, and 3A4 but not with P450 2E1 or 2A6.Larynx cytosols also showed appreciable aromatic amine N-acetyltransferase activity for p-aminobenzoic acid (NAT-1) but not for sulfamethazine (NAT-2); however, NAT-1 activity was not correlated with total DNA adducts, which is again consistent with the lack of aromatic amine-DNA adducts detected by P-32-postlabeling. Thus, these results suggest that the DNA adducts detected in human larynx are largely derived from metabolic activation of polycyclic aromatic hydrocarbons in cigarette smoke by P450 2C, 3A4, and/or 1A1.

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    Degawa M, Stern SJ, Guengerich FP, Fu PP, Ilett K, Kaderlik RK et al. Metabolic activation and carcinogen-DNA adduct detection in human larynx. Cancer Research. 1994;54:4915-4919.