TY - JOUR
T1 - 2,3,7,8-Tetrachlorodibenzo-p-dioxin and diindolymethanes differentially induce cytochrome P450 1A1, 1B1, and 19 in H295R human adrenocortical carcinoma cells
AU - Sanderson, J. Thomas
AU - Slobbe, Lennert
AU - Lansbergen, Gideon W.A.
AU - Safe, Stephen
AU - Van Den Berg, Martin
PY - 2001
Y1 - 2001
N2 - Diindolylmethane (DIM) is an acid-catalyzed condensation product of indole-3-carbinol, a constituent of cruciferous vegetables, and is formed in the stomach. DIM alters estrogen metabolism and inhibits carcinogen-induced mammary tumor growth in rodents. DIM is a weak agonist for the aryl hydrocarbon (Ah) receptor and blocks the effects of estrogens via inhibitory Ah recptor-estrogen receptor cross-talk. DIM and various structural analogs were examined in H295R cells for effects on 3 cytochrome P450 (CYP) enzymes involved in estrogen synthesis and/or metabolism: CYP1A1, CYP1B1, and CYP19 (aromatase). Aromatase activity was measured by conversion of 1β-3H-androstenedione to estrone and 3H2O. H295R cells were exposed to the test chemicals dissolved in dimethyl sulfoxide for 24 h prior to analyses. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) (0-30 nM) and DIM (0-10μM) induced ethoxyresorufin-O-deethylase (EROD) activity, as a measure of CYP1A1 and possibly 1B1 activity, with EC50 values of about 0.3 nM and 3 μM, respectively. DIM, but not TCDD, induced aromatase activity with an apparently maximal 2-fold increase at 10 μM; higher concentrations of DIM and many of its analogs were cytotoxic. TCDD (30 nM) significantly increased CYP1A1 and 1B1 mRNA levels, but had no effect on mRNA for CYP19. DIM (3μM) significantly increased mRNA levels for all three CYPs. DIM analogs with substitutions on the 5 and 5′ positions (3μM) induced aromatase and EROD activity, together with mRNA levels of CYP1A1, 1B1, and 19; analogs that were substituted on the central carbon of the methane group showed little or no inductive activity toward the CYPs. In conclusion, DIM and several of its analogs appear to induce CYPs via multiple yet distinct pathways in H295R human adrenocortical carcinoma cells.
AB - Diindolylmethane (DIM) is an acid-catalyzed condensation product of indole-3-carbinol, a constituent of cruciferous vegetables, and is formed in the stomach. DIM alters estrogen metabolism and inhibits carcinogen-induced mammary tumor growth in rodents. DIM is a weak agonist for the aryl hydrocarbon (Ah) receptor and blocks the effects of estrogens via inhibitory Ah recptor-estrogen receptor cross-talk. DIM and various structural analogs were examined in H295R cells for effects on 3 cytochrome P450 (CYP) enzymes involved in estrogen synthesis and/or metabolism: CYP1A1, CYP1B1, and CYP19 (aromatase). Aromatase activity was measured by conversion of 1β-3H-androstenedione to estrone and 3H2O. H295R cells were exposed to the test chemicals dissolved in dimethyl sulfoxide for 24 h prior to analyses. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) (0-30 nM) and DIM (0-10μM) induced ethoxyresorufin-O-deethylase (EROD) activity, as a measure of CYP1A1 and possibly 1B1 activity, with EC50 values of about 0.3 nM and 3 μM, respectively. DIM, but not TCDD, induced aromatase activity with an apparently maximal 2-fold increase at 10 μM; higher concentrations of DIM and many of its analogs were cytotoxic. TCDD (30 nM) significantly increased CYP1A1 and 1B1 mRNA levels, but had no effect on mRNA for CYP19. DIM (3μM) significantly increased mRNA levels for all three CYPs. DIM analogs with substitutions on the 5 and 5′ positions (3μM) induced aromatase and EROD activity, together with mRNA levels of CYP1A1, 1B1, and 19; analogs that were substituted on the central carbon of the methane group showed little or no inductive activity toward the CYPs. In conclusion, DIM and several of its analogs appear to induce CYPs via multiple yet distinct pathways in H295R human adrenocortical carcinoma cells.
KW - Aromatase
KW - CYP19
KW - CYP1A1
KW - CYP1B1
KW - Diindolymethane
KW - TCDD
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U2 - 10.1093/toxsci/61.1.40
DO - 10.1093/toxsci/61.1.40
M3 - Article
C2 - 11294972
AN - SCOPUS:0035036028
SN - 1096-6080
VL - 61
SP - 40
EP - 48
JO - Toxicological Sciences
JF - Toxicological Sciences
IS - 1
ER -