Metabolism of benzo[a]pyrene and benzo[a]pyrene-7,8-diol by human cytochrome P450 1B1

被引:241
作者
Kim, JH [1 ]
Stansbury, KH [1 ]
Walker, NJ [1 ]
Trush, MA [1 ]
Strickland, PT [1 ]
Sutter, TR [1 ]
机构
[1] Johns Hopkins Univ, Sch Hyg & Publ Hlth, Dept Environm Hlth Sci, Baltimore, MD 21205 USA
关键词
D O I
10.1093/carcin/19.10.1847
中图分类号
R73 [肿瘤学];
学科分类号
100214 ;
摘要
Benzo[a]pyrene (B[a]P), a ubiquitous environmental, tobacco and dietary carcinogen, has been implicated in human cancer etiology, The role of human cytochrome P450 1B1 in the metabolism of B[a]P is poorly understood. Using microsomal preparations of human P450 1A1, 1A2 and 1B1 expressed in baculovirus-infected insect cells, as well as human and rat P450 1B1 expressed in yeast, we have determined the metabolism of B[a]P, with and without the addition of exogenous epoxide hydrolase, and B[a]P-7,8-dihydrodiol (7,8-diol), each substrate at a concentration of 10 mu M. HPLC analysis detected eight major metabolites of B[a]P and four metabolites of the 7,8-diol, The results of these studies indicate that cytochrome P450 1B1 carries out metabolism of B[a]P along the pathway to the postulated ultimate carcinogen, the diol epoxide 2, at rates much higher than P450 1A2 but less than P450 1A1, The rates of formation of the 7,8-diol metabolite in incubations with epoxide hydrolase are 0.17 and 0.38 nmol/min/nmol P450 for human P450 1B1 and 1A1, respectively, and undetectable for 1A2, The rates of total tetrol metabolite formation from the 7,8-diol, which are indicative of diol epoxide formation, are 0.60, 0.43 and 2.58 nmol/min/nmol P450 for 1B1, 1A2 and 1A1 respectively. In agreement with other reports of rat P450 1B1 activity, our data show this rat enzyme to be very active for B[a]P and 7,8-diol, with rates higher than human P450 1B1, In addition to the established role of P450 1A1 in B[a]P metabolism P450 1B1 may significantly contribute to B[a]P and 7,8-diol metabolism and carcinogenesis in rodent tumor models and in humans.
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页码:1847 / 1853
页数:7
相关论文
共 35 条
[21]   MOUSE ENDOMETRIUM STROMAL CELLS EXPRESS A POLYCYCLIC AROMATIC HYDROCARBON-INDUCIBLE CYTOCHROME-P450 THAT CLOSELY RESEMBLES THE NOVEL P450 IN MOUSE EMBRYO FIBROBLASTS (P450EF) [J].
SAVAS, U ;
CHRISTOU, M ;
JEFCOATE, CR .
CARCINOGENESIS, 1993, 14 (10) :2013-2018
[22]  
Shimada T, 1996, CANCER RES, V56, P2979
[23]   THE ROLE OF 12-CDNA-EXPRESSED HUMAN, RODENT, AND RABBIT CYTOCHROMES-P450 IN THE METABOLISM OF BENZO[A]PYRENE AND BENZO[A]PYRENE TRANS-7,8-DIHYDRODIOL [J].
SHOU, MG ;
KORZEKWA, KR ;
CRESPI, CL ;
GONZALEZ, FJ ;
GELBOIN, HV .
MOLECULAR CARCINOGENESIS, 1994, 10 (03) :159-168
[24]  
Shou MG, 1996, MOL CARCINOGEN, V17, P241, DOI 10.1002/(SICI)1098-2744(199612)17:4<241::AID-MC8>3.0.CO
[25]  
2-G
[26]  
SUTTER TR, 1994, J BIOL CHEM, V269, P13092
[27]   Isolation and characterization of the human cytochrome p450 CYP1B1 gene [J].
Tang, WM ;
Wo, YYP ;
Stewart, J ;
Hawkins, AL ;
Griffin, CA ;
Sutter, TR ;
Greenlee, WF .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1996, 271 (45) :28324-28330
[28]   Induction and localization of cytochrome P4501B1 (CYP1B1) protein in the livers of TCDD-treated rats: detection using polyclonal antibodies raised to histidine-tagged fusion proteins produced and purified from bacteria [J].
Walker, NJ ;
Crofts, FG ;
Li, Y ;
Lax, SF ;
Hayes, CL ;
Strickland, PT ;
Lucier, GW ;
Sutter, TR .
CARCINOGENESIS, 1998, 19 (03) :395-402
[29]   RAT CYP1B1 - AN ADRENAL CYTOCHROME-P450 THAT EXHIBITS SEX-DEPENDENT EXPRESSION IN LIVERS AND KIDNEYS OF TCDD-TREATED ANIMALS [J].
WALKER, NJ ;
GASTEL, JA ;
COSTA, LT ;
CLARK, GC ;
LUCIER, GW ;
SUTTER, TR .
CARCINOGENESIS, 1995, 16 (06) :1319-1327
[30]  
Wei QY, 1996, CANCER RES, V56, P3975