Cytochrome b(5) plays a dual role in the reaction cycle of cytochrome P450 3A4 during oxidation of the anticancer drug ellipticine

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F62156489%3A43210%2F17%3A43912464" target="_blank" >RIV/62156489:43210/17:43912464 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11130/17:10364693 RIV/00216208:11310/17:10364693 RIV/00064203:_____/17:10364693

Výsledek na webu

<a href="http://dx.doi.org/10.1007/s00706-017-1986-9" target="_blank" >http://dx.doi.org/10.1007/s00706-017-1986-9</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00706-017-1986-9" target="_blank" >10.1007/s00706-017-1986-9</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Cytochrome b(5) plays a dual role in the reaction cycle of cytochrome P450 3A4 during oxidation of the anticancer drug ellipticine

Popis výsledku v původním jazyce

Ellipticine is an anticancer agent that forms covalent DNA adducts after enzymatic activation by cytochrome P450 (CYP) enzymes, mainly by CYP3A4. This process is one of the most important ellipticine DNA-damaging mechanisms for its antitumor action. Here, we investigated the efficiencies of human hepatic microsomes and human recombinant CYP3A4 expressed with its reductase, NADPH:CYP oxidoreductase (POR), NADH:cytochrome b5 reductase and/or cytochrome b5 in SupersomesTM to oxidize this drug. We also evaluated the effectiveness of coenzymes of two of the microsomal reductases, NADPH as a coenzyme of POR, and NADH as a coenzyme of NADH:cytochrome b5 reductase, to mediate ellipticine oxidation in these enzyme systems. Using HPLC analysis we detected up to five ellipticine metabolites, which were formed by human hepatic microsomes and human CYP3A4 in the presence of NADPH or NADH. Among ellipticine metabolites, 9-hydroxy-, 12-hydroxy-, and 13-hydroxyellipticine were formed by hepatic microsomes as the major metabolites, while 7-hydroxyellipticine and the ellipticine N2-oxide were the minor ones. Human CYP3A4 in SupersomesTM generated only three metabolic products, 9-hydroxy-, 12-hydroxy-, and 13-hydroxyellipticine. Using the 32P-postlabeling method two ellipticine-derived DNA adducts were generated by microsomes and the CYP3A4-Supersome system, both in the presence of NADPH and NADH. These adducts were derived from the reaction of 13-hydroxy- and 12-hydroxyellipticine with deoxyguanosine in DNA. In the presence of NADPH or NADH, cytochrome b5 stimulated the CYP3A4-mediated oxidation of ellipticine, but the stimulation effect differed for individual ellipticine metabolites. This heme protein also stimulated the formation of both ellipticine-DNA adducts. The results demonstrate that cytochrome b5 plays a dual role in the CYP3A4-catalyzed oxidation of ellipticine: (1) cytochrome b5 mediates CYP3A4 catalytic activities by donating the first and second electron to this enzyme in its catalytic cycle, indicating that NADH:cytochrome b5 reductase can substitute NADPH-dependent POR in this enzymatic reaction and (2) cytochrome b5 can act as an allosteric modifier of the CYP3A4 oxygenase.

Název v anglickém jazyce

Cytochrome b(5) plays a dual role in the reaction cycle of cytochrome P450 3A4 during oxidation of the anticancer drug ellipticine

Popis výsledku anglicky

Ellipticine is an anticancer agent that forms covalent DNA adducts after enzymatic activation by cytochrome P450 (CYP) enzymes, mainly by CYP3A4. This process is one of the most important ellipticine DNA-damaging mechanisms for its antitumor action. Here, we investigated the efficiencies of human hepatic microsomes and human recombinant CYP3A4 expressed with its reductase, NADPH:CYP oxidoreductase (POR), NADH:cytochrome b5 reductase and/or cytochrome b5 in SupersomesTM to oxidize this drug. We also evaluated the effectiveness of coenzymes of two of the microsomal reductases, NADPH as a coenzyme of POR, and NADH as a coenzyme of NADH:cytochrome b5 reductase, to mediate ellipticine oxidation in these enzyme systems. Using HPLC analysis we detected up to five ellipticine metabolites, which were formed by human hepatic microsomes and human CYP3A4 in the presence of NADPH or NADH. Among ellipticine metabolites, 9-hydroxy-, 12-hydroxy-, and 13-hydroxyellipticine were formed by hepatic microsomes as the major metabolites, while 7-hydroxyellipticine and the ellipticine N2-oxide were the minor ones. Human CYP3A4 in SupersomesTM generated only three metabolic products, 9-hydroxy-, 12-hydroxy-, and 13-hydroxyellipticine. Using the 32P-postlabeling method two ellipticine-derived DNA adducts were generated by microsomes and the CYP3A4-Supersome system, both in the presence of NADPH and NADH. These adducts were derived from the reaction of 13-hydroxy- and 12-hydroxyellipticine with deoxyguanosine in DNA. In the presence of NADPH or NADH, cytochrome b5 stimulated the CYP3A4-mediated oxidation of ellipticine, but the stimulation effect differed for individual ellipticine metabolites. This heme protein also stimulated the formation of both ellipticine-DNA adducts. The results demonstrate that cytochrome b5 plays a dual role in the CYP3A4-catalyzed oxidation of ellipticine: (1) cytochrome b5 mediates CYP3A4 catalytic activities by donating the first and second electron to this enzyme in its catalytic cycle, indicating that NADH:cytochrome b5 reductase can substitute NADPH-dependent POR in this enzymatic reaction and (2) cytochrome b5 can act as an allosteric modifier of the CYP3A4 oxygenase.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

30204 - Oncology

Projekt

<a href="/cs/project/GA17-12816S" target="_blank" >GA17-12816S: Konstrukce modifikovaných apoferitinových nanočástic s protinádorovými léčivy a studium mechanismů potencujících jejich efektivitu v terapii</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Monatshefte für Chemie - Chemical Monthly

ISSN

0026-9247

e-ISSN

—

Svazek periodika

148

Číslo periodika v rámci svazku

11

Stát vydavatele periodika

AT - Rakouská republika

Počet stran výsledku

9

Strana od-do

1983-1991

Kód UT WoS článku

000413626000012

EID výsledku v databázi Scopus

2-s2.0-85021791759