17β-Estradiol hydroxylation catalyzed by human cytochrome P450 1A1: A comparison of the activities induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in MCF-7 cells with those from heterologous expression of the cDNA

Spink, David C.; Eugster, Hans-Pietro; Lincoln, David W.; Schuetz, John D.; Schuetz, Erin G.; Johnson, Judith A.; Kaminsky, Laurence S.; Gierthy, John F.

doi:10.1016/0003-9861(92)90404-k

Cited by 216 publications

(122 citation statements)

References 34 publications

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“…Co-PCBs and PCDD, which are dioxins, have a marked affinity to aryl hydrocarbon receptor (AhR), and the first step of manifestation of the toxicity is the binding of these dioxins and this receptor in cytoplasm [12][13][14] . Top: Control rats(1-4).…”

Section: Resultsmentioning

confidence: 99%

Micro two-dimensional electrophoretic analysis of changes in plasma proteins of next-generation rat of the pregnant rats administered to coplanar PCBs

et al. 2006

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SUMMARYPolychlorinated biphenyl (PCB) 126 or PCB 169 was administered to pregnant rats and kinetic changes in plasma protein spots of their next generation (F2 rats) ages 1, 3, 6, and 15 weeks were observed by micro two-dimensional polyacrylamide gel electrophoresis (M2D-PAGE).In the control group in which age-related changes were observable, changes in the form of the albumin (Alb) spot were recognized at ages 1-3 weeks. Only the Alb spot on the acid side, i.e., non-mercaptoalbumin, was recognized at age 1 week. At age 3 weeks, the Alb spot on the alkaline side, i.e., mercaptoalbumin, also became observable. On the other hand, qualitative changes in the form of Alb, i.e., manifestations of mercaptoalbumin, were recognized at age 1 week by administration of PCB 126. This result suggested that the influence of PCB 126 on the living body is greater than that of PCB 169. In spite of the treatment for toxicity by equivalence of dose control on the basis of toxicity equivalency factor (TEF) 0.1 for PCB 126 (PeCB) and 0.01 for PCB 169 (HxCB), the influence of PCB 126 on the living body was greater than that of PCB 169.The C3 spot was increased at age 3 weeks in the PCB 126 and the PCB 169. The spot showed a tendency toward increase at age 6 weeks in the PCB 126. The TEF compared PCB169 with PCB126, and distinctly increase of the C3 spot was observed for 15 weeks though the TEF was low. From these, as for the PCB 169, it was suggested appearing remarkably in aging influence of the immunity toxicity.The observations of the changes in these spots led to the conclusion that the changes in these spots resulted from transfer of the drugs accumulating in the maternal body to the F2 rats of the maternal rats administered PCB 126 and those administered PCB 169 via the breast milk and that these changes are involved with inflammatory proteins, including the target genes influenced by the toxicity of coplanar PCBs.

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Section: Resultsmentioning

confidence: 99%

Micro two-dimensional electrophoretic analysis of changes in plasma proteins of next-generation rat of the pregnant rats administered to coplanar PCBs

et al. 2006

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“…with respect to oestrogen metabolism as breast cancer is an oestrogen-dependent tumour. Dioxin induction of MCF-7 breast cancer cells resulted in marked NADPH-dependent 4-hydroxylation of 17fl-oestradiol which was not inhibited by an anti-CYP1A1 antibody [18] and was inhibited by an antibody raised against mouse P450EF [19], now identified as murine CYP1B 1 [20], suggesting that CYP1B 1 may contribute to the 4-hydroxylation of oestradiol.…”

Section: Discussionmentioning

confidence: 99%

“…Sodium dodecyl sulphate polyacrylamide gel electrophoresis and immunoblotting of breast tumours using an enhanced chemiluminescence technique to identify immunoreactive proteins were performed as described previously [17,18].…”

Section: Immunoblottingmentioning

confidence: 99%

Expression of cytochrome P450 CYP1B1 in breast cancer

et al. 1995

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The expression of CYP1B1 has been identified in breast cancer using the reverse transcriptase-polymerase chain reaction and immunoblotting. CYP1B1 mRNA was expressed in the majority of breast tumours and immunoblotting of breast tumours identified a single protein band of molecular weight 60 kDa corresponding to the predicted molecular weight of human CYP1B1. This is the first study to identify CYP1B1 expression in a turnout where it may represent a previously unknown pathway for the metabolism of oestradiol and chemotherapeutic drugs.

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“…Kitawaki et al [18] reported results showing that the ratio of aromatase to AHH activity was much higher in smoker placentas than in normal placentas. Moreover, Spink et al [27] reported that P450 1A1 catalyzed the hydroxylation of estradiol at the C-2, C-15a, and C-6a in incubations with microsomes from 2, 3, 7, 8-tetrachlorodibenzo-pdioxin-treated MCF-7 cells, whereas the expression of P450 1A2 in human liver is known to catalyze microsomal hydroxylation predominantly at C-2. These reports could be one of the explanations of our results that the elevated estrogen 2-hydroxylase activity in PIH placentas might be catalyzed by aromatase P450 and another inducible cytochrome P450.…”

Section: Discussionmentioning

confidence: 99%

Aromatase and Estrogen 2-Hydroxylase Activities of Human Placental Microsomes in Pregnancy-Induced Hypertension.

et al. 1996

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Abstract. 2-Hydroxylationis one of the major metabolic pathways of estrogens and is believed to be catalyzed by a form of cytochrome P450. Recently it has been reported that estrogen 2-hydroxylase activity in human placenta is catalyzed by aromatase.Some investigators suggested the effect of catechol estrogen on human placental steroidogenesis which may be related to pregnancy-induced hypertension (PIH) through the inhibition of catechol-0-methyltransferase (COMT) activity. In order to better understand the interrelationship between placental aromatase and estrogen 2-hydroxylase activities in PIH patients, both activities were evaluated in the PIH placentas.Human placental microsomes obtained from PIH patients were incubated with [1/3-3H]androstenedione or [2-3H]estradiol in the presence of NADPH. Aromatase and estrogen 2-hydroxylase activities were assessed by the tritium water method. The immunosuppression patterns of both activities due to monoclonal antiaromatase cytochrome P450 antibody (MAb3-2C2) were studied. Estrogen 2-hydroxylase activity was significantly higher in PIH placentas (4.7 ± 0.9 pmol/min/mg protein, n=7) than in normal placentas (3.0 ± 0.7 pmol/min/mg protein, n=7). When the PIH placental microsomes were subjected to immunosuppression by 1 to 100 µg IgG of MAb3-2C2, estrogen 2-hydroxylase activity was suppressed by 94 to 65% whereas aromatase activity was strongly suppressed by 72 to 17%, respectively. From our results of high estrogen 2-hydroxylase activity in PIH placentas, it is assumed that there is a different estrogen catalyzing mechanism in PIH placentas.

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17β-Estradiol hydroxylation catalyzed by human cytochrome P450 1A1: A comparison of the activities induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in MCF-7 cells with those from heterologous expression of the cDNA

Cited by 216 publications

References 34 publications

Micro two-dimensional electrophoretic analysis of changes in plasma proteins of next-generation rat of the pregnant rats administered to coplanar PCBs

Micro two-dimensional electrophoretic analysis of changes in plasma proteins of next-generation rat of the pregnant rats administered to coplanar PCBs

Expression of cytochrome P450 CYP1B1 in breast cancer

Aromatase and Estrogen 2-Hydroxylase Activities of Human Placental Microsomes in Pregnancy-Induced Hypertension.

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