• Toxicological Research
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• v.26 no.3
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• pp.171-175
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• 2010

The human genome contains approximately 13 orphan cytochrome P450 (P450, CYP) genes, of which the apparent function or substrate has not been identified. However, they seem to possess their own biological relevance in some tissues or developmental stages. Here, we characterized the heterologously expressed CYP2W1, an orphan P450 enzyme. The recombinant CYP2W1 protein containing a $6{\times}$(His)-tag at Nterminus has been expressed in Escherichia coli and purified. Expression level of CYP2W1 holoenzyme was around 500 nmol P450 holoenzyme per liter culture medium. The reduced CO difference spectrum of CYP2W1 showed a maximum absorption at 449 nm. CYP2W1 indicated the significant induction to bioactivate Trp-P-1, MeIQ, and IQ in E. coli DJ701 tester strain. However, the bioactivation of B[$\alpha$]P, and NNK by CYP2W1 was relatively low. The model structure of CYP2W1 suggested the characteristic P450 folds with the lengths and orientations of the individual secondary elements. The F-G loop is situated on the distal side of heme to accommodate the flexibility of active site of CYP2W1. These studies can provide useful information for the finding of its biological roles and structure-function relationships of an orphan CYP2W1 enzyme.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.5
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• pp.339-342
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• 2012

Inter-individual pharmacokinetic variation of H2-receptor antagonist is related to genetic polymorphism of CYP2C19. We investigated the frequency of CYP2C19 genetic polymorphism and the treatment duration of cimetidine by CYP2C19 genotypes in functional dyspeptic patients without definite causes who were treated with cimetidine in Korea. One hundred subjects with functional dyspepsia participated in this study from March 1, 2010 to June 30, 2011. They were tested by upper gastrointestinal endoscopy and treated for their dyspepsia with cimetidine. The single nucleotide polymorphisms (SNPs) of CYP2C19 were genotyped using the Seeplex CYP2C19 ACE Genotyping system. There were no significant differences in the demographic, clinical, or laboratory findings among the CYP2C19 subgroups which are wild type homozygote (W/W), heterozygote (W/V), and variant homozygote (V/V). The frequencies of CYP2C19 subgroups were 33 (33%) in W/W, 49 (49%) in W/V, and 18 (18%) in V/V, respectively. The mean duration of cimetidine treatment (in weeks) was the shortest in the V/V among the CYP2C19 genotypes (W/W: $5.1{\pm}1.5$, W/V: $4.0{\pm}1.7$, V/V: $2.1{\pm}0.7$; p<0.001). This study can also act as a basis for further investigation to identify the underlying genetic, epigenetic, or environmental factors in CYP2C19 enzyme activity.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.3
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• pp.837-846
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• 2012

Breast cancer (BCa) is the leading type of cancer in Mexican women. Genetic factors, such as single nucleotide polymorphisms (SNP) of P450 system, have been reported in BCa. In this report, and for the first time in the literature, we analyzed the rs3735684 (7021 G>A), rs11553651 (15016 G>T) and rs56195291 (60020 C>G) polymorphisms in the CYP2W1, 4F11 and 8A1 genes in patients with BCa and in healthy Mexican women to identify a potential association between these polymorphisms and BCa risk. Patients and controls were used for polymorphism analysis using an allelic discrimination assay with TaqMan probes and confirmed by DNA sequencing. Links with clinic-pathological characteristics were also analyzed. Statistical analysis was performed using the standard ${\chi}^2$ or Fisher exact test statistic. No significant differences were observed in the distributions of CYP2W1 (OR 8.6, 95%CI 0.43-172.5 P>0.05; OR 2.0, 95%CI 0.76-5.4, P>0.05) and CYP4F11 (OR 0.3, 95%CI 0.01-8.4 P>0.05) genotypes between the patients and controls. Only the CYP8A1 CC genotype was detected in patients with BCa and the controls. All polymorphism frequencies were in Hardy-Weinberg Equilibrium (HWE) in the controls (P>0.05). We found a significant association between BCa risk and smoking, use of oral contraceptives or hormonal replacement therapy (HRT), obesity, hyperglycemia, chronic diseases, family history of cancer and menopausal status in the population studied (P<0.05). Tobacco, oral contraceptive or HRT, chronic diseases and obesity or overweight were strongly associated with almost eight, thirty-five, nine and five-fold increased risk for BCa. Tobaco, obesity and hyperglycemia significantly increased the risk of BCa in the patients carrying variant genotypes of CYP2W1 (P<0.05). These results indicate that the CYP2W1 rs3735684, CYP4F11 rs11553651 and CYP8A1 rs56195291 SNPs are not a key risk factor for BCa in Mexican women. This study did not detect an association between the CYP2W1, 4F11 and 8A1 genes polymorphisms and BCa risk in a Mexican population. However, some clinico-pathological risk factors interact with CYP2W1 genotypes and modifies susceptibility to BCa.

• Biomedical Science Letters
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• v.19 no.4
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• pp.310-314
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• 2013

CYP2E1 in the liver has been studied intensively because it is involved in the metabolic activation of xenobiotics. It is inducible by alcohol, so it has been suspected as the cause of cancer in the stomach and lung. The possible role of CYP2E1 has been suggested strongly as causing tissue damage in mice with renal failure. It was also suspected that 5'-flanking region of CYP2E1 gene might be involved with renal failure. So, we investigated polymorphism of restriction enzyme sites within CYP2E1 gene using the PCR-RFLP analysis. PstI and RsaI sites were located at 5'-flanking region and DraI site was located at intron 6. All three types (W/W, W/S, S/S) were observed for these enzymes although each incidence was somewhat different depending the enzyme sites. W/W was prominent for PstI whereas W/S was markedly high for RsaI. Overall, polymorphic incidence in patients was somewhat higher than normal population. This research should facilitate further investigation of CYP2E1 at genetic level as the direct cause of tissue damage in various organs.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2647-2653
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• 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.

• Molecules and Cells
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• v.39 no.3
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• pp.211-216
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• 2016

CYP107W1 from Streptomyces avermitilis is a cytochrome P450 enzyme involved in the biosynthesis of macrolide oligomycin A. A previous study reported that CYP107W1 regioselectively hydroxylated C12 of oligomycin C to produce oligomycin A, and the crystal structure of ligand free CYP107W1 was determined. Here, we analyzed the structural properties of the CYP107W1-oligomycin A complex and characterized the functional role of the Trp178 residue in CYP107W1. The crystal structure of the CYP107W1 complex with oligomycin A was determined at a resolution of $2.6{\AA}$. Oligomycin A is bound in the substrate access channel on the upper side of the prosthetic heme mainly by hydrophobic interactions. In particular, the Trp178 residue in the active site intercalates into the large macrolide ring, thereby guiding the substrate into the correct binding orientation for a productive P450 reaction. A Trp178 to Gly mutation resulted in the distortion of binding titration spectra with oligomycin A, whereas binding spectra with azoles were not affected. The Gly178 mutant's catalytic turnover number for the 12-hydroxylation reaction of oligomycin C was highly reduced. These results indicate that Trp178, located in the open pocket of the active site, may be a critical residue for the productive binding conformation of large macrolide substrates.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.953-958
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• 2015

Background: Expression of KRT13, FAIM2 and CYP2W1 appears to be influenced by risk habits, thus exploring the associations of these genes in oral squamous cell cancer (OSCC) with risk habits, clinico-pathological parameters and patient survival may be beneficial in identifying relevant biomarkers with different oncogenic pathways. Materials and Methods: cDNAs from 41 OSCC samples with and without risk habits were included in this study. Quantitative real-time PCR was used to analyze KRT13, FAIM2 and CYP2W1 in OSCC. The housekeeping gene (GAPDH) was used as an endogenous control. Results: Of the 41 OSCC samples, KRT13 was down-regulated in 40 samples (97.6%), while FAIM2 and CYP2W1 were down-regulated in 61.0% and 48.8%, respectively. Overall, there were no associations between KRT13, FAIM2 and CYP2W1 expression with risk habits, selected socio-demographic and clinico-pathological parameters and patient survival. Conclusions: Although this study was unable to show significance, there were some tendencies in the associations of KRT13, FAIM2 and CYP2W1 expression in OSCC with selected clinic-pathological parameters and survival.

• Fisheries and Aquatic Sciences
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• v.9 no.2
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• pp.64-69
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• 2006

Cytochrome P450 (CYP1A) gene expression in the liver and sex steroid levels in plasma were investigated in olive flounder (Paralichthys olivaceus) exposed to tributyltin (TBT) and benzo[a]pyrene (BaP). We constructed a cDNA library and cloned a 230-base sequence encoding partial CYP1A DNA. The CYP1A gene expression level was estimated using northern blotting. Hepatic CYP1A mRNA levels in fish injected with BaP at 10 mg/kg body weight (b.w.) increased for 48 h after injection. However, fish injected with both BaP and TBT at 10 mg/kg b.w. showed no significant changes in CYP1A mRNA level after 48 h. Plasma concentrations of testosterone and $17{\beta}$-estradiol were not significantly different in males and females injected with BaP and TBT. We suggest that TBT-induced suppression of BaP bioactivity should be interpreted with caution in biomonitoring field studies.

• Journal of Microbiology and Biotechnology
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• v.31 no.3
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• pp.464-474
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• 2021

Bacterial cytochrome P450 (CYP) enzymes are responsible for the hydroxylation of diverse endogenous substances with a heme molecule used as a cofactor. This study characterized two CYP154C3 proteins from Streptomyces sp. W2061 (CYP154C3-1) and Streptomyces sp. KCCM40643 (CYP154C3-2). The enzymatic activity assays of both CYPs conducted using heterologous redox partners' putidaredoxin and putidaredoxin reductase showed substrate flexibility with different steroids and exhibited interesting product formation patterns. The enzymatic characterization revealed good activity over a pH range of 7.0 to 7.8 and the optimal temperature range for activity was 30 to 37℃. The major product was the C16-hydroxylated product and the kinetic profiles and patterns of the generated hydroxylated products differed between the two enzymes. Both enzymes showed a higher affinity toward progesterone, with CYP154C3-1 demonstrating slightly higher activity than CYP154C3-2 for most of the substrates. Oxidizing agents (diacetoxyiodo) benzene (PIDA) and hydrogen peroxide (H2O2) were also utilized to actively support the redox reactions, with optimum conversion achieved at concentrations of 3 mM and 65 mM, respectively. The oxidizing agents affected the product distribution, influencing the type and selectivity of the CYP-catalyzed reaction. Additionally, CYP154C3s also catalyzed the C-C bond cleavage of steroids. Therefore, CYP154C3s may be a good candidate for the production of modified steroids for various biological uses.

• Proceedings of the PSK Conference
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• 2000.04a
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• pp.129.2-129.2
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• 2000