• Archives of Pharmacal Research
• /
• 제26권8호
• /
• pp.631-637
• /
• 2003

Chloroquine has been used for many decades in the prophylaxis and treatment of malaria. It is metabolized in humans through the N-dealkylation pathway, to desethylchloroquine (DCQ) and bisdesethylchloroquine (BDCQ), by cytochrome P450 (CYP). However, until recently, no data are available on the metabolic pathway of chloroquine. Therefore, the metabolic pathway of chloroquine was evaluated using human liver microsomes and cDNA-expressed CYPs. Chloroquine is mainly metabolized to DCQ, and its Eadie-Hofstee plots were biphasic, indicating the involvement of multiple enzymes, with apparent $K_m and V_{max}$ values of 0.21 mM and 1.02 nmol/min/mg protein 3.43 mM and 10.47 nmol/min/mg protein for high and low affinity components, respectively. Of the cDNA-expressing CYPs examined, CYP1A2, 2C8, 2C19, 2D6 and 3A4/5 exhibited significant DCQ formation. A study using chemical inhibitors showed only quercetin (a CYP2C8 inhibitor) and ketoconazole (a CYP3A4/5 inhibitor) inhibited the DCQ formation. In addition, the DCQ formation significantly correlated with the CYP3A4/5-catalyzed midazolam 1-hydroxylation (r=0.868) and CYP2C8-catalyzed paclitaxel 6$\alpha$-hydroxylation (r = 0.900). In conclusion, the results of the present study demonstrated that CYP2C8 and CYP3A4/5 are the major enzymes responsible for the chloroquine N-deethylation to DCQ in human liver microsomes.

• 생명과학회지
• /
• 제26권1호
• /
• pp.42-49
• /
• 2016

레티노산(RA)는 많은 유형의 세포에서 성장 및 발달에 중요한 역할을 수행하며 생체 활성화에 적합한 RA의 농도는 CYP26A1 등 여러 가지 효소에 의해 조절된다. CYP26A1의 발현은 RA에 의해서 조절되며 CYP26A1는 RA에 반응하는 유전자 중 하나이다. CYP26A1 유전자 클로닝은 여러 동물에서 보고되어 있지만, 소에서 CYP26A1 유전자의 클로닝은 아직 보고되지 않았다. 소로부터 CYP26A1의 프로모터 부위를 중합효소 연쇄반응을 이용하여 클로닝 한 후 다른 동물과 염기 서열 비교분석 결과 RARE DR-5 (ttggg)의 존재를 확인하였고, DR-5의 염기서열은 분석한 종 에서 완전히 일치하였다. DR-5 motif를 함유한 소의 CYP26A1 프로모터 부위를luciferase리포터 유전자에 결합한 후 transient transfection에 의해 promoter 발현을 분석하였다. 폐 유래 세포주인 MTCC 세포에서 CYP26A1 promoter의 발현은 ATRA의 처리에 의하여 촉진되었다. CYP26A1 유전자의 발현은 ATRA 의존적으로 RAR-α 및 RAR-β에 의하여 현저하게 촉진되었다. 그러나 RAR-γ나 RXR-γ는 CYP26A1 발현에 별다른 영향을 미치지는 않았다. 또한 MTCC 세포주가 생산하는 내인성 CYP26A1 유전자 발현을 Q-RT-PCR로 분석한 결과 1-2일간의 ATRA 처리에 의해서는 현저한 영향을 받지 않으나, 3일 동안 ATRA를 처리한 샘플에서는 CYP26A1의 발현이 현저하게 감소하였다. 결론적으로, 소의 CYP26A1유전자의 프로모터 부위에 존재하는 DR-5 RARE는 RAR-α 및 RAR-β의 결합부위로 작용하여 MTCC 세포에서 CYP26A1 유전자 발현 조절과 RA signal의 조절에 관여하는 것을 확인하였다.

• 한국해양생명과학회지
• /
• 제7권2호
• /
• pp.145-153
• /
• 2022

수은은 생물 축적과 먹이사슬을 통한 생물 농축되며, 미량에서도 유해한 영향을 나타내기 때문에 해양 환경 내에서 중요한 문제가 되고 있다. 그러나 해양 소형 갑각류에 대한 수은의 생물 영향은 다른 금속에 비해 연구가 미흡하다. 본 연구에서는 기수산 물벼룩 Diaphanosoma celebensis을 아치사 농도(0.2, 0.4, 0.8 ㎍/l)의 무기 수은(HgCl₂)에 48시간 노출시킨 후, 대사 관련 유전자의 발현 양상을 조사하였다. 해독효소 유전자 5종(cytochrome P450; cyp360A1, cyp361A1, cyp4AP3, cyp4C122, cyp370C5)과 소화효소 6종(alpha amylase (AMY), alpha amylase related protein (AMY-like), trypsin (TRYP), chymotrypsin-like protein (CHY), lipase (LIP), pancreatic lipase-related protein (PLRP))의 유전자 발현을 quantitative real time reverse transcription polymerase chain reaction (qRT-PCR)을 이용하여 분석하였다. Cyp 유전자의 경우 clan2에 속하는 cyp370C5와 clan4에 속하는 cyp4AP3 유전자의 발현이 농도 의존적으로 유의하게 증가하였다. 한편 소화효소 유전자 중에서는 단백질 소화와 관련 있는 TRYP 유전자의 발현이 농도 의존적으로 증가하였다. 이러한 결과는 cyp370C5와 cyp4AP3가 수은 독성을 해독하는 과정에서 중요한 역할을 담당할 것으로 보이며, 수은이 소화효소 유전자의 발현을 조절함으로써 에너지 대사에 영향을 미칠 수 있음을 제시한다. 본 연구는 해양 소형 갑각류에서 수은에 대한 분자 수준의 영향을 이해하는데 도움이 될 것이다.

• Toxicological Research
• /
• 제33권3호
• /
• pp.211-218
• /
• 2017

Cytochrome P450 1B1 (CYP1B1) acts as a hydroxylase for estrogen and activates potential carcinogens. Moreover, its expression in tumor tissues is much higher than that in normal tissues. Despite this association between CYP1B1 and cancer, the detailed molecular mechanism of CYP1B1 on cancer progression in HeLa cells remains unknown. Previous reports indicated that the mRNA expression level of Herc5, an E3 ligase for ISGylation, is promoted by CYP1B1 suppression using specific small interfering RNA, and that ISGylation may be involved in ubiquitination related to ${\beta}-catenin$ degradation. With this background, we investigated the relationships among CYP1B1, Herc5, and ${\beta}-catenin$. RT-PCR and western blot analyses showed that CYP1B1 overexpression induced and CYP1B1 inhibition reduced, respectively, the expression of $Wnt/{\beta}-catenin$ signaling target genes including ${\beta}-catenin$ and cyclin D1. Moreover, HeLa cells were treated with the CYP1B1 inducer $7,12-dimethylbenz[{\alpha}]anthracene$ (DMBA) or the CYP1B1 specific inhibitor, tetramethoxystilbene (TMS) and consequently DMBA increased and TMS decreased ${\beta}-catenin$ and cyclin D1 expression, respectively. To determine the correlation between CYP1B1 expression and ISGylation, the expression of ISG15, a ubiquitin-like protein, was detected following CYP1B1 regulation, which revealed that CYP1B1 may inhibit ISGylation through suppression of ISG15 expression. In addition, the mRNA and protein expression levels of Herc5 were strongly suppressed by CYP1B1. Finally, an immunoprecipitation assay revealed a direct physical interaction between Herc5 and ${\beta}-catenin$ in HeLa cells. In conclusion, these data suggest that CYP1B1 may activate $Wnt/{\beta}-catenin$ signaling through stabilization of ${\beta}-catenin$ protein from Herc5-mediated ISGylation for proteosomal degradation.

• 한국해양생명과학회지
• /
• 제8권2호
• /
• pp.104-114
• /
• 2023

플라스틱은 전세계적으로 사용량이 증가함에 따라 해양 환경으로 유입되는 플라스틱 쓰레기의 양도 꾸준히 증가하고 있으며, 미세플라스틱은 해양 생물에 의해 섭취되어 소화관에 축적됨에 따라 성장과 생식에 유해한 영향을 미친다. Cytochrome P450 (CYP)는 환경 오염물질을 대사하는 해독효소로 알려져 있으나 지각류에서는 그 기능에 대해서는 잘 알려져 있지 않다. 본 연구에서는 기수산 물벼룩 Diaphanosoma celebensis에서 clan 2, 3, 4에 각각 속하는 CYP 유전자 9종(clan 2: CYP370A4, CYP370C5; clan 3: CYP350A1, CYP350C5, CYP361A1; clan 4: CYP4AN-like, CYP4AP2, CYP4AP3, CYP4C33-like1)의 서열에 대해 진화적으로 보존된 서열의 유사도를 분석하고 계통분석을 실시하였다. 또한 3종류의 서로 다른 크기의 polystyrene beads (0.05-, 0.5-, 6-㎛ PS beads; 0.1, 1, and 10 mg/L)에 48시간 노출된 기수산 물벼룩에서 이들 9종의 CYP 유전자의 발현을 real time reverse transcription polymerase chain reaction (RT-PCR)로 분석하였다. 결과적으로 기수산 물벼룩 CYP 유전자는 모두 진화적으로 보존된 motif를 가지고 있으며 계통분석 결과 각각 clan 2, 3, 4에 속하는 것으로 확인되었다. 이는 기능적으로 보존되어 있음을 의미한다. CYP 유전자 중 clan 2에 속하는 CYP370C5와 clan 3에 속하는 CYP360A1, 그리고 clan 4에서는 CYP4C122 유전자의 발현이 0.05-㎛ PS beads에 노출되었을 때 유의하게 증가하는 양상을 보였으며, 이는 이들 유전자가 PS 대사에 관여한다는 것을 의미한다. 본 연구는 미세플라스틱이 해양 무척추 동물에 미치는 생물 영향을 분자적 수준에서 이해하는데 도움이 될 것이다.

• Archives of Pharmacal Research
• /
• 제20권5호
• /
• pp.404-409
• /
• 1997

Trout CYP1A-CAT expression construct was generated by cloning -3.5 Kb $5^I$ flanking DNA of trout liver CYP1A gene in front of CAT gene at pCAT-basic vector. Hepa 1 cells, which are known to contain a functional arylhydrbcarbon $receptor^I$ were transfected with trout CYP1A-CAT using lipofectin. 3-Methylcholanthrene (1 nM) was added into hepa 1 cells in culture in order to examine if $5^I$ flanking DNA of trout CYP1A gene could interact with mouse transactivating factors to bring about transcription of the chloramphenicol acetyltransferase(CAT) reporter gene. The level of CAT protein was measured by CAT ELISA and the level of CAT mRNA was determined by RTPCR. The treatment of 1 nM 3-methylcholanthrene resulted in two fold increases in CAT protein as well as CAT mRNA compared to untreated control hepa 1 cells. These data indicate that arylhydrocarbon receptors of mouse hepa 1 cells are functional to activate exogenously transfected trout CYP1A-CAT construct in terms of both transcription and translation of CAT. We also examined the effect of 3-methylcholanthrene on endogenous cyplal activity in hepa 1 cell. 3-Methylcholanthrene (1 nM) treatment to hepa 1 cells trahsfected with trout CYP1A-CAT construct stimulated the level of cyp1a1 mRNA by two folds and the activity of ethoxyresorufin-O-deethylase by two fold compared to that of control cells. In this study we reported that trout CYP1A-CAT reporter gene expression construct could be expressed by 3-methylcholanthrene treatment in mouse hepa 1 cells. Thus trout CYP1A-CAT could serve as a good model to study the mechanism of regulation of CYP1A1 gene expression.

• Toxicological Research
• /
• 제13권1_2호
• /
• pp.117-125
• /
• 1997

In order to assess the possibility whether CYP2D is involved in caffeine metabolism, we have purified and characterized the rat liver microsomal cytochrome P4502D1 (CYP2D1), equivalent to CYP2D6 in human liver, and have utilized the reconstituted CYP2D1 in the metabolism of 4 primary caffeine (1, 3, 7-trimethylxanthine) metabolites such as paraxanthine (1, 7-dimethylxanthine), 1, 3, 7-trimethylurate, theophylline (1, 3-dimethylxanthine) and theobromine (3, 7-dimethylxanthine). Rat liver CYP 2D1 has been purified to a specific content of 8.98 nmole/mg protein (13.4fold purification, 1.5% yield) using $\omega$-aminooctylagarose, hydroxlapatite, and DE52 columns in a sequential manner. As judged from sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), the purified CYP2D1 was apparently homogeneous. Molecular weight of the purified CYP2D1 was found to be 51, 000 Da. Catalytic activity of the purified and then reconstituted CYP2D1 was confirmed by using bufuralol, a known subsFate of CYP2D1. The reconstituted CYP2D1 was found to produce to 1-hydroxylbufuralol at a rate of 1.43$\pm$0.13 nmol/min/nmol P450. The kinetic analysis of bufuralol hydroxylation indicated that Km and Vmax values were 7.32$\mu M$ and 1.64 nmol/min/nmol P450, respectively. The reconstituted CYP2D1 could catalyze the 7-demethylation of PX to 1-methylxanthine at a rate of 12.5 pmol/min/pmol, and also the 7- and 3- demethylations of 1, 3, 7-trimethylurate to 1, 3-dimethylurate and 1, 7-dimethylurate at 6.5 and 12.8 pmol/min/pmol CYP2D1, respectively. The reconstituted CYP2D1 could also 3-demethylate theophylline to 1-methylxanthine at 5 pmol/min/pmol and hydroxylate the theophylline to 1, 3-dimethylurate at 21.8 pmol/min/pmol CYP2D1. The reconstituted CYP2D1, however, did not metabolize TB at all (detection limits were 0.03 pmol/min/pmol). This study indicated that CYP2D1 is involved in 3-and 7-demethylations of paraxanthine and theophylline and suggested that CYP2D6 (equivalent to CYP2D1 in rat liver) present in human liver may be involved in the secondary metabolism of the primary metabolites of caffeine.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
• /
• pp.149.3-150
• /
• 2003

CYP3A4 is the most abundant human CYP and oxidizes a diversity of substrates. including various drugs. steroids. and carcinogens. A variety of metal ions are known to affect microsomal monooxygenase activities. Effects of a series of divalent metal ions on the CYP3A4-catalyzed reaction of reconstituted system containing purified CYP3A4. NADPH-P450 reductase (NPR), and cytochrome b5 (b5) were examined. (omitted)

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권6호
• /
• pp.2647-2653
• /
• 2012

Involvement of cytochrome P450 genes (CYPs) in breast cancer (BCa) may differ between populations, with expression patterns affected by tumorigenesis. This may have an important role in the metabolism of anticancer drugs and in the progression of cancer. The aim of this study was to determine the mRNA expression patterns of four cytochrome P450 genes (CYP2W1, 3A5, 4F11 and 8A1) in Mexican women with breast cancer. Real-time PCR analyses were conducted on 32 sets of human breast tumors and adjacent non-tumor tissues, as well as 20 normal breast tissues. Expression levels were tested for association with clinical and pathological data of patients. We found higher gene expression of CYP2W1, CYP3A5, CYP4F11 in BCa than in adjacent tissues and only low in normal mammary glands in our Mexican population while CYP8A1 was only expressed in BCa and adjacent tissues. We found that Ki67 protein expression was associated with clinicopathological features as well as with CYP2W1, CYP4F11 and CYP8A1 but not with CYP3A5. The results indicated that breast cancer tissues may be better able to metabolize carcinogens and other xenobiotics to active species than normal or adjacent non-tumor tissues.

• The Korean Journal of Physiology and Pharmacology
• /
• 제17권6호
• /
• pp.479-484
• /
• 2013

Given the CYP3A4 and CYP3A5's impact on the efficacy of drugs, the genetic backgrounds of individuals and populations are regarded as an important factor to be considered in the prescription of personalized medicine. However, genetic studies with Korean population are relatively scarce compared to those with other populations. In this study, we aimed to identify CYP3A4/5 polymorphisms and compare the genotype distributions among five ethnicities. To identify CYP3A4/5 SNPs, we first performed direct sequencing with 288 DNA samples which consisted of 96 Koreans, 48 European-Americans, 48 African-Americans, 48 Han Chinese, and 48 Japanese. The direct sequencing identified 15 novel SNPs, as well as 42 known polymorphisms. We defined the genotype distributions, and compared the allele frequencies among five ethnicities. The results showed that minor allele frequencies of Korean population were similar with those of the Japanese and Han Chinese populations, whereas there were distinct differences from European-Americans or African-Americans. Among the pharmacogenetic markers, frequencies of $CYP3A4^*1B$ (rs2740574) and $CYP3A5^*3C$ (rs776742) in Asian groups were different from those in other populations. In addition, minor allele frequency of $CYP3A4^*18$ (rs28371759) was the highest in Korean population. Additional in silico analysis predicted that two novel non-synonymous SNPs in CYP3A5 (+27256C>T, P389S and +31546T>G, I488S) could alter protein structure. The frequency distributions of the identified polymorphisms in the present study may contribute to the expansion of pharmacogenetic knowledge.