• Journal of Preventive Medicine and Public Health
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• v.31 no.1 s.60
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• pp.1-14
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• 1998

The genetically determined CYP2D6 activity as considered to be associated with cancer susceptibility with inter-individual variation. Genetic polymorphism of CYP2D6(B) and CYP2D6(T) was determined by the two polymerase chain reaction(PCR) and BstN1 and EcoN1 restriction fragment length polymorphisms(RFLP) for 67 lung cancer cases and 95 healthy volunteer controls. The cases were composed of 26 squamous cell carcinoma, 14 small cell carcinoma, 10 adenocarcinoma, 3 large cell undifferentiated carcinoma, and 14 not histologically diagnosed. The results were gained from the 142 subjects (57 cases and 85 controls) who observed successfully in two PCR and BstNl/EcoN1 RELP. Only one and no mutant allele of the CYP2D6(B) and CYP2D6(T) gene was detected, that is, the frequency of mutant allele was very low; 0.7%(1/142) and 0%(0/142), respectively. Detected mutant allele of the CYP2D6(B) was beterozygous type(WM). The odds ratios for lung cancer susceptibility with CYP2D6(B) and CYP2D6(T) genotype were not calculated. These results are similar to the previous understanding that the mutant allele is very rare in Orientals compared to Caucasians, therefore, it considered that CYP2D6(B) and CYP2D6(T) genotypes have maybe no association with lung cancer susceptibility in Koreans. This is the basic data of CYP2D6(B) and CYP2D6(T) genotypes for Koreans. It would be hepful for further study to determine lung cancer susceptibility of Koreans with the data about CYP1A1, CYP2E1, GSTM1 from future study.

• Korean Journal of Biological Psychiatry
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• v.7 no.2
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• pp.140-146
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• 2000

P450 CYP2D6 enzyme(=debrisoquine hydroxylase) is known to metabolize many neuroleptics and some genetic polymorphisms in the CYP2D6 gene were reported to be associated with tardive dyskinesia(TD). We investigeted the association of two genetic polymorphisms in the CYP2D6 gene, $CYP2D6^*4$ and $CYP2D6^*10$, with TD in Korean schizophrenic subjects. Subjects consisted of 71 Korean schizophrenics and TD was evaluated using the Abnormal Involuntary Movement Scale (AIMS). There were no statistically significant differences in the demographic variables of age, male to female percentage and the current antipsychotic(CPZ equivalent) dose between the group with TD and the group without TD. But the duration of antipsychotic drug exposure was significantly higher in the group without TD(p=0.000, by independent t-test). The mean AIMS score in the group with TD was $11.2{\pm}6.6$(S.D.). Genotypings for the presence of $CYP2D6^*4$ and $CYP2D6^*10$ were done using PCR amplifications and endonuclease digestions. There were no statistically significant genotypic and alleleic associations between TD and $CYP2D6^*4$(by chisquare tests), and between TD and $CYP2D6^*10$(by chi-square tests). These results indicate that the $CYP2D6^*4$ and $CYP2D6^*10$ polymorphisms have no significant roles in the causation of TD.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.3
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• pp.213-217
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• 2006

We evaluated the potential of major components of Phellodendri cortex to inhibit the activities of CYP2D6 and p-glycoprotein. The abilities of berberine, palmatine, limonin, and rutaecarpine to inhibit CYP2D6-mediated dextromethorphan O-demethylation and calcein AM accumulation were tested using human liver microsomes and L-MDR1 cell, respectively. Berberine strongly inhibited CYP2D6 isoform activity, whereas limonin and reuaecarpine did not. The $IC_{50}$ value of berberine was reduced after preincubation with microsomes in the presence of NADPH generating system, suggesting that berberine is a mechanism based inhibitor. In addition, all chemicals tested, didn't show inhibitory effect on p-glycoprotein activity. These results suggest that berberine has potential to inhibit CYP2D6 activity in vitro. Therefore, in vivo studies investigating the interactions between berberine and CYP2D6 substrates are necessary to determine whether inhibition of CYP2D6 activity by berberine is clinically relevant.

• YAKHAK HOEJI
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• v.46 no.3
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• pp.179-184
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• 2002

The abuse of dextromethorphan has been prevalent for 15 years in Korea and its fatal cases were reported even though it has proved to be very safe. In this study, to investigate the safety and tolerance assessment of dextromethorphan, the metabolic phenotyping and genotype of dextromethorphan were studied. After a single 30 mg of dextromethorphan oral administration to 74 volunteers, concentration of dextromethorphan and its metabolites, dextrorphan, hydroxymorphinan and methoxymorphinan were measured in urine which collected during 8hrs after the drug administration. CYP2D6 phenotype was determined from the ratio of dextromethorphan to dextrorphan. GC/MS was used to quantify dextromethorphan and its metabolites. For genotyping, mutant alleles of the CYP2D6 gene were identified. 24 subjects (32.4％) were homozygous for CYP2D6＊10B, 29 subjects (39.2％) were heterozygous for this allele, while in 21 subjects (28.4％) no exon 1 mutation could be found. The frequency of CYP2D6＊10B-allele containing the 188C T mutation was 54％ of total subjects studied.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.238.2-239
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• 2003

The purposes of this study were to evaluate the relationship between the genetic polymorphisms in CYP2D6*10 allele, MDR1 (exon 21 and 26) gene and risperidone pharmacokinetics in healthy male Korean subjects. A single dose of 2 mg risperidone tablet was given orally to 23 healthy male Korean volunteers. Blood samples were taken during the 12 hours after the dose. Serum concentrations of risperidone and 9-hydroxyrisperidone were measured using HPLC with UV detector. 23 subjects were genotyped for CYP2D6*10 allele, MDR1 G2677 T and C3435T by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). (omitted)

• Childhood Kidney Diseases
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• v.26 no.1
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• pp.63-67
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• 2022

Nephrocalcinosis often occurs in infants and is caused by excessive calcium or vitamin D supplementation, neonatal primary hyperparathyroidism, and genetic disorders. Idiopathic infantile hypercalcemia (IIH), a rare cause of nephrocalcinosis, results from genetic defects in CYP24A1 or SLC34A1. Mutations in CYP24A1, which encodes 25-hydroxyvitamin D 24-hydroxylase, disrupt active vitamin D degradation. IIH clinically manifests as failure to thrive and hypercalcemia within the first year of life and usually remits spontaneously. Herein, we present a case of IIH wih CYP24A1 mutations. An 11-month-old girl visited our hospital with incidental hypercalcemia. She showed failure to thrive, and her oral intake had decreased over time since the age of 6 months. Her initial serum parathyroid hormone level was low, 25-OH vitamin D and 1,25(OH)₂ vitamin D levels were normal, and renal ultrasonography showed bilateral nephrocalcinosis. Whole-exome sequencing revealed compound heterozygous variants in CYP24A1 (NM_000782.4:c.376C>T [p.Pro126Ser] and c.1310C>A [p.Pro437His]). Although her hypercalcemia and poor oral intake spontaneously resolved in approximately 8 months, we suggested that her nephrocalcinosis and renal function be regularly checked in consideration of potential asymptomatic renal damage. Hypercalcemia caused by IIH should be suspected in infants with severe nephrocalcinosis, especially when presenting with failure to thrive.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6101-6104
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• 2012

Background: Breast cancer accounts about one million from total annual ten million new diagnosed cases of neoplasia worldwide and is the main cause of death due to cancer in women. Tamoxifen is the most popular selective estrogen receptor modulator used in anti estrogen treatments. Tamoxifen must be converted into its metabolite endoxifen for biologic effects; this conversion process is catalysed by highly polymorphic cytochrome P450 2D6 (CYP2D6). This study surveyed copy number variation of the CYP2D6 gene and its possible correlation with Tamoxifen resistance in breast cancer patients. Methods: This case control study was performed on samples taken from 79 patients with breast cancer who used tamoxifen in Yazd and Tehran Cities, Iran. Real time reactions were conducted for 10 healthy samples using the comparative $C_t$ (Cycles threshold) method, each pair of genes being compared and samples with ratios around 1 were taken as control samples. Proliferation reactions were done by Real-Time PCR ABI Prism 7500. All registered data were transformed into SPSS 15 program and analyzed. Results: Efficiency of PCR for both CYP2D6 and ALB genes was 100%. From all 23 drug resistant patients 21.7% had one copy, 47.8% two copies and 30.4% had three copies. Also from all 56 drug sensitive patients, 26.8% had one copy, 51.8% two copies and 21.4% had three copies. The percentage of patients with one and two copies was similar between two groups but patients with three copies were more likely to belong to the drug resistant group more. Odd ratios for one and two copies were 0.759 and 0.853 respectively, indicating possible protective effects while that for three copies was 1.604. Conclusions: Based on our study there is no significant link between CYP2D6 gene copy numbers and tamoxifen resistance in women with breast cancer. But more studies considering other influencing factors appear warranted.

• Clinical and Experimental Pediatrics
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• v.48 no.4
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• pp.380-386
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• 2005

Purpose : The incidence of nonphysiologic neonatal hyperbilirubinemia is twice as high in East Asians as in whites. Recently, UGT1A1 mutation was found to be a risk factor for neonatal hyperbilirubinemia. In congenitally-jaundiced Gunn rats, which lack expression of UDP-glucuronosyltransferase, alternative pathways can be stimulated by inducers of CYP1A1 and CYP1A2 enzymes. CYP1A2 plays a major role in bilirubin degradation of the alternate pathway. We studied the relationship between UGT1A1 and CYP1A2 gene polymorphism of neonatal hyperbilirubinemia in Koreans. Methods : Seventy-nine Korean full term neonates who had hyperbilirubinemia(serum bilirubin >12 mg/dL) without obvious causes of jaundice, were analyzed for UGT1A1 and CYP1A2 gene polymorphism; the control group was sixty-eight. We detected the polymorphism of Gly71Arg of UGT1A1 gene by direct sequencing and T2698G of CYP1A2 by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) using MboII and direct sequencing. Results : Allele frequency of Gly71Arg mutation in the hyperbilirubinemia group was 32 percent, which was significantly higher than 11 percent in the control group(P<0.0001). Mutant gene frequency of T2698G was 41.8 percent in patients and 32.3 percent in the control group(P=0.015), but allele frequency was 21 percent in patients and 19 percent in the control group, which was not significantly higher(P=0.706). There was no relationship between mutations of two genes(P=0.635). Conclusion : The polymorphism of UGT1A1 gene(Gly71Arg) and CYP1A2 gene(T2698G) was detected in Korean neonatal hyperbilirubinemia. Only polymorphisms of Gly71Arg in UGT1A1 were significantly higher than control group.

• Korean Journal of Biological Psychiatry
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• v.18 no.2
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• pp.95-100
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• 2011

Objectives To evaluate the drug interactions between aripiprazole and haloperidol, authors investigated plasma concentrations of those drugs by genotypes. Method Fifty six patients with a confirmed Diagnostic and Statistical Manual of Mental Disorders 4th edition diagnosis of schizophrenia were enrolled in this eight-week, double blind, placebo-controlled study. Twenty-eight patients received adjunctive aripiprazole treatment and twenty-eight patients received placebo while being maintained on haloperidol treatment. Aripiprazole was dosed at 15 mg/day for the first 4 weeks, and then 30 mg for the next 4 weeks. The haloperidol dose remained fixed throughout the study. Plasma concentrations of haloperidol and aripiprazole were measured by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) at baseline, week 1, 2, 4 and 8. $^*1$, $^*5$, and $^*10$ B alleles of CYP2D6 and $^*1$ and $^*3$ alleles of CYP3A5 were determined. The Student's T-test, Pearson's Chi-square test, Wilcoxon Rank Sum test and Logistic Regression analysis were used for data analysis. All tests were two-tailed and significance was defined as an alpha < 0.05. Results In the frequency of CYP2D6 genotype, $^*1/^*10$ B type was most frequent (36.5%) and $^*1/^*1$ (30.8%), $^*10B/^*10B$ (17.3%) types followed. In the frequency of CYP3A5 genotype, $^*3/^*3$ type was found in 63.5% of subjects, and $^*1/^*3$ type and $^*1/^*1$ were 30.8% and 5.8% respectively. The plasma levels of haloperidol and its metabolites did not demonstrate significant time effects and time-group interactions after adjunctive treatment of aripiprazole. The genotypes of CYP2D6 and 3A5 did not affect the plasma concentration of haloperidol in this trial. No serious adverse event was found after adding aripiprazole to haloperidol. Conclusion No significant drug interaction was found between haloperidol and aripiprazole. Genotypes of CYP2D6 and 3A5 did not affect the concentration of haloperidol after adding aripiprazole.

• Journal of Preventive Medicine and Public Health
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• v.55 no.3
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• pp.280-288
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• 2022

Objectives: One of the most widely used pesticides today is chlorpyrifos (CPF). Cytochrome P450 (CYP)2B6, the most prominent catalyst in CPF bioactivation, is highly polymorphic. The objective of our study was to evaluate the role of CYP2B6^*6, which contains both 516G>T and 785A>G polymorphisms, in CPF toxicity, as represented by the concentration of 3,5,6-trichloro-2-pyridinol (TCPy), among vegetable farmers in Central Java, Indonesia, where CPF has been commonly used. Methods: A cross-sectional study was conducted among 132 vegetable farmers. Individual socio-demographic and occupational characteristics, as determinants of TCPy levels, were obtained using a structured interviewer-administered questionnaire and subsequently used to estimate the cumulative exposure level (CEL). TCPy levels were detected with liquid chromatography-mass spectrometry. CYP2B6^*6 gene polymorphisms were analyzed using a TaqMan^® SNP Genotyping Assay and Sanger sequencing. Linear regression analysis was performed to analyze the association between TCPy, as a biomarker of CPF exposure, and its determinants. Results: The prevalence of CYP2B6^*6 polymorphisms was 31% for ^*1/^*1, 51% for ^*1/^*6, and 18% for ^*6/^*6. TCPy concentrations were higher among participants with CYP2B6^*1/^*1 than among those with ^*1/^*6 or ^*6/^*6 genotypes. CYP2B6^*6 gene polymorphisms, smoking, CEL, body mass index, and spraying time were retained in the final linear regression model as determinants of TCPy. Conclusions: The results suggest that CYP2B6^*6 gene polymorphisms may play an important role in influencing susceptibility to CPF exposure. CYP2B6^*6 gene polymorphisms together with CEL, smoking habits, body mass index, and spraying time were the determinants of urinary TCPy concentrations, as a biomarker of CPF toxicity.