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Introduction: Warfarin is an anticoagulant whose efficacy depends on reaching and maintaining an INR (International Normalized Ratio) within therapeutic ranges. Up to 60% of interindividual dose-response variability can be explained by pharmacogenes, in this regard there are no studies in Peru. We studied the effect of the CYP4F2 gene on the dose of warfarin in Peruvian patients. Material and Methods: A descriptive and ambispective observational study was carried out with patients seen in the Grau ESSALUD Hospital Hematology Service, Lima, Peru, selected by non-probabilistic convenience sampling. The inclusion criteria were patients anticoagulated for more than three months and with stable doses of warfarin (same dose for at least three outpatient visits and with an INR in therapeutic ranges of 2.5-3.5). Analysis of the CYP4F2 gene was performed by taking a DNA sample from peripheral blood. Results: 70 patients with a mean age of 69.6 + 13.4, male 38 (54.39%) and female 32 (45.7%) entered the study. The mean dose of warfarin was 31.6 + 15.2 mg/week. The genotypic frequency of the CYP4F2 gene, rs2108622 variant (C>T) was 55 (78%), 13 (19%) and 2 (3%) of CC, CT, TT, respectively. No deviation from the Hardy-Weinberg equilibrium was found in the variants studied (p=0.56). Mean warfarin doses/week of the CC, CT, TT genotypes were 30.34 + 11.98; 36.4 + 25.6 and 36.25 + 1.8 mg/week, respectively (p=0.397). Conclusion: In conclusion, it appears that CYP4F2 gene genotypes do not have a significant effect on warfarin dose. [ABSTRACT FROM AUTHOR]

Purpose: As the most common subset of breast cancer (BC), estrogen receptor positive (ER+) BC accounting for 80% of cases, has become a global public health concern. The female hormone estrogen (E2) unequivocally drives ER + breast malignancies. The reasons that estrogen affects BC development has long been considered, yet further study remains to be conducted of the molecular events in the E2-estrogen receptor α (ERα) signaling pathway in ER + BC progression, especially lipid metabolism, so providing more options for tailored and individualized therapy. Our aim is to find out new targets and clinical biomarkers for ER + breast cancer treatment from the perspective of lipid metabolism. Methods: Lipid metabolomics profiling was used to examine the membrane phospholipid stimulated by E2. Clinical BC samples were used to assess the association of CYP4F2, CYP4F11 expression with clinicopathological characteristics and patient outcomes. Some inhibitors of main enzymes in AA metabolism were used combined with E2 to assess roles of CYP4F2/CYP4F11 in the progression of ER + BC. CYP4F2, CYP4F11 overexpression and knockdown BC cell lines were employed to examine the effects of CYP4F2, CYP4F11 on cellular proliferation, apoptosis and tumor growth. Western blotting, qPCR, Immunohistochemical staining and flow cytometry were also conducted to determine the underlying mechanisms related to CYP4F2, CYP4F11 function. Results: The activation of the CYP450 signaling pathway in arachidonic acid metabolism contributed to ER + BC tumorigenesis. In ER + BC, CYP4F2 and CYP4F11 overexpression induced by E2 could promote cancer cell proliferation and resistance to apoptosis by producing the metabolite 20-HETE and activating the antiapoptotic protein Bcl-2. CYP4F2 and CYP4F11 elevation correlates with poorer overall survival and disease-free survival in ER + BC patients. Conclusion: CYP4F2, CYP4F11 and their metabolite 20-HETE could serve as effective prognostic markers and attractive therapeutic targets for novel anticancer drug development about ER + BC.

Kang Huang,1,* Tianyi Ma,1,* Qiang Li,1 Yilei Zhou,2 Ting Qin,1 Zanrui Zhong,1 Shilin Tang,1 Wei Zhang,1 Jianghua Zhong,1 Shijuan Lu1 1Department of Cardiovascular Medicine, Central South University Xiangya School of Medicine Affiliated Haikou Hospital, Haikou, People’s Republic of China; 2Medical College, Jingchu University of Technology, Jingmen, Hubei, People’s Republic of China*These authors contributed equally to this workCorrespondence: Shijuan Lu, Department of Cardiovascular Medicine, Central South University Xiangya School of Medicine Affiliated Haikou Hospital, No. 43, Renmin Avenue, Haidian Island, Haikou, Hainan, 570100, People’s Republic of China, Tel/Fax +86-13005013999, Email lushijuan122@163.comBackground: The pathophysiological mechanism of ischemic stroke is complex. Traditional risk factors cannot fully or only partially explain the occurrence and development of IS. Genetic factors are getting more and more attention. Our study aimed to explore the association between CYP4F2 gene polymorphism and susceptibility to IS.Methods: A total of 1322 volunteers were enrolled to perform an association analysis through SNPStats online software. Using FPRP (false-positive report probability) to detect whether the result is a noteworthy finding. The interaction of SNP-SNP in IS risk was assessed by multi-factor dimensionality reduction. Statistical analysis of this study was mainly completed by SPSS 22.0 software.Results: Mutant allele “A” (OR = 1.24) and genotype “AA” (OR = 1.49) or “GA” (OR = 1.26) of CYP4F2-rs2108622 are risk genetic factors for IS. Rs2108622 is significantly associated with an increased risk of IS among subjects who are females, aging > 60 years old, with BMI ≥ 24 kg/m2, and smoking or drinking volunteers. CYP4F2-rs3093106 and -rs3093105 are associated with susceptibility to IS among smoking, drinking subjects, or IS patients complicated with hypertension.Conclusion: CYP4F2-rs2108622, -rs3093106, and -rs3093105 are associated with an increased risk of IS.Keywords: ischemic stroke, susceptibility, CYP4F2, genetic variants, association analysis

Li Zhao,1 Zhenguo Zhai,2 Pengmei Li1 1Pharmacy Department, China-Japan Friendship Hospital, Beijing, People’s Republic of China; 2Department of Respiratory and Critical Care Medicine, China-Japan Friendship Hospital, Beijing, People’s Republic of ChinaCorrespondence: Pengmei Li, Pharmacy Department, China-Japan Friendship Hospital, No. 2 Yinghua East Road, Beijing, People’s Republic of China, Tel +86-1084205661, Email lipengmei@yeah.netAbstract: One 59-year-old female patient with deep venous thrombosis (DVT) and pulmonary embolism (PE) was treated with 6 mg warfarin once daily as an anticoagulant. Before taking warfarin, her international normalized ratio (INR) was 0.98. Two days after warfarin treatment, her INR did not change from baseline. Due to the high severity of the PE, the patient needed to reach her target range (INR goal = 2.5, range = 2~3) rapidly, so the dose of warfarin was increased from 6 mg daily to 27 mg daily. However, the patient’s INR did not improve with the dose escalation, still maintaining an INR of 0.97– 0.98. We drew a blood sample half an hour before administering 27 mg warfarin and detected single nucleotide polymorphism for the following genes, which were identified to be relevant with warfarin resistance: CYP2C9 rs1799853, rs1057910, VKORC1 rs9923231, rs61742245, rs7200749, rs55894764, CYP4F2 rs2108622, and GGCX rs2592551. The trough plasma concentration of warfarin was 196.2 ng/mL after 2 days of warfarin administration with 27 mg QD, which was much lower than the therapeutic drug concentration ranges of warfarin (500– 3,000 ng/mL). The genotype results demonstrate that the CYP4F2gene has rs2108622 mutation which can explain some aspect of warfarin resistance. Further investigations are necessary to fully characterize other pharmacogenomics or pharmacodynamics determinants of warfarin dose-response in Chinese.Keywords: anticoagulation, warfarin resistance, CYP2C9, VKORC1, CYP4F2, GGCX, warfarin plasma concentration

The aim. To evaluate the efficacy and safety of warfarin (WF) therapy in patients with atrial fibrillation (AF) using pharmacogenetic dosing method at an anticoagulant monitoring office according to the results of a one-year prospective follow-up. Materials and methods. The study involved 110 patients with AF (mean age 68.72 ± 0.79; men – 57, women – 53). By the method of stratified randomization, the patients with AF were divided into two groups: the main group – 50 patients with AF and genotype-guided dosing method, the control group – 60 patients with AF and clinical dosing method. The outcomes were examined after the one-year follow-up: excessive hypocoagulation episodes (INR > 4) and bleeding. CYP2C9, CYP4F2, VKORC1 gene polymorphisms were determined using multiplex real time polymerase chain reaction; INR was controlled monthly; CHA2DS2-VASC, HAS-BLED, SAMe-TT2R2 scale scores were evaluated; TTR was calculated using the Rosendaal method. Results. The distribution of CYP2C9, CYP4F2, VKORC1 genotypes in the main and control groups were in accordance with the Hardy–Weinberg equilibrium. In patients with AF and genotype-guided dosing, the frequency and risk of excessive hypocoagulation episodes (χ2 = 5.11; P < 0.05; RR = 0.50 (CI 0.27; 0.94)) and bleeding (χ2 = 9.57; P < 0.05; RR = 0.41 (CI 0.22; 0.77)) were significantly lower. However, the groups did not differ in TTR. The validity of genetic-guided dosing was confirmed by the comparability of the medians and the direct correlation between the calculated and therapeutic WF doses (r = +0.57; P < 0.05). There were no relationships between TTR, excessive hypocoagulation episodes, hemorrhagic complications and clinical and genetic factors in the main group. Conclusions. In patients with AF, the use of genotype-guided dosing method in the anticoagulant monitoring office helped to reduce the frequency and risk of excessive hypocoagulation episodes and bleeding as well as eliminate the influence of endogenous and exogenous factors in the personalized management of patients.

Background: Our study aimed to explore the potential association of CYP4F2 gene polymorphisms with lung cancer (LC) risk. Methods: The five variants in CYP4F2 were genotyped using Agena MassARRAY in 507 cases and 505 controls. Genetic models and haplotypes based on logistic regression analysis were used to evaluate the potential association between CYP4F2 polymorphisms and LC susceptibility. Results: This study observed that rs12459936 was linked to an increased risk of LC in no-smoking participants (allele: OR = 1.38, p = 0.035; homozygote: OR = 2.00, p = 0.035; additive: OR = 1.40, p = 0.034) and females (allele: OR = 1.64, p = 0.002; homozygote: OR = 2.57, p = 0.006; heterozygous: OR = 2.56, p = 0.001; dominant: OR = 2.56, p < 0.002; additive: OR = 1.67, p = 0.002). Adversely, there was a significantly decreased LC risk for rs3093110 in no-smoking participants (heterozygous: OR = 0.56, p = 0.027; dominant: OR = 0.58, p = 0.035), rs3093193 (allele: OR = 0.66, p = 0.016; homozygote: OR = 0.33, p = 0.011; recessive: OR = 0.38, p = 0.021; additive: OR = 0.64, p = 0.014), rs3093144 (recessive: OR = 0.20, p = 0.045), and rs3093110 (allele: OR = 0.54, p = 0.010; heterozygous: OR = 0.50, p = 0.014; dominant: OR = 0.49, p = 0.010; additive: OR = 0.54, p = 0.011) in females. Conclusions: The study demonstrated that CYP4F2 variants were associated with LC susceptibility, with evidence suggesting that this connection may be affected by gender and smoking status. [ABSTRACT FROM AUTHOR]

The aim. To investigate the influence of clinical and genetic factors on the stability of warfarin’s anticoagulant effect in patients with atrial fibrillation (AF) during the year. Materials and methods. The study involved 60 patients with AF, age 70.50 (64.25; 76.25) years (32 men and 28 women). Coagulogram indexes with International Normalized Ratio (INR) were determined using Coag Chrome 3003 monthly; the CHA2DS2-VASC, HAS-BLED, SAMe-TT2R2 scales scores were evaluated; the calculation of TTR was performed using the Rosendaal method. CYP2C9, CYP4F2, VKORC1 genes polymorphisms were determined using multiplex real time polymerase chain reaction in CFX-96 thermocycler (BioRad). Results. Median TTR in groups of patients with SAMe-TT2R2 score 0.05). There were significantly more patients with TTR 4) were detected in 21 (40 %) patients during the year. Excessive hypocoagulation was significantly more common in patients carrying the allele A of the VKORC1 gene in comparison with non-carriers (51.43 % versus 24.00 %; χ2 = 4.57, P < 0.05). The presence of mutant allele A was associated with 2.14-fold higher risk of excessive hypocoagulation (RR = 2.14; CI 1.06–4.69). Taking amiodarone (χ2 = 3.13; P < 0.05) had a significant effect on the development of excessive hypocoagulation with a relative risk RR = 1.83 (CI 1.01–3.35). Conclusions. SAMe-TT2R2 score can be useful to predict poor INR control, while VKORC1 genotype estimating – to predict excessive hypocoagulation episodes. An integrated approach using clinical and genetic methods is needed to determine the potential efficacy and safety of warfarin therapy.

To identify the impact of CYP2C9*2, *3, VKORC1−1639 G>A and CYP4F2*3 on warfarin dose in an Arab population. To compare the accuracy of a clinical warfarin dosing (CWD) versus genetic warfarin dosing algorithms (GWD) during warfarin initiation. A cohort of Arab patients newly starting on warfarin had their dose calculated using CWD published in www.warfarindosing.org and were followed for 1 month. Each patient provided a saliva sample. DNA was extracted, purified and genotyped for VKORC−1639 G>A, CYP2C9*2, CYP2C9*3 and CYP4F2*3. After reaching warfarin maintenance dose, the dose was recalculated using the GWD and median absolute error (MAE) and the percentage of warfarin doses within 20% of the actual dose were calculated and compared for the two algorithms. The study enrolled 130 patients from 12 Arabian countries. Compared to those with wild type, carriers of reduced function alleles in CYP2C9 required significantly lower median (IQR) warfarin weekly dose [24.5 (15.3) vs. 35 (29.8) mg/week, p=0.006]. With regards to VKORC , patients with AA genotype had a significantly lower median (IQR) weekly warfarin dose compared to AG and GG [21(10.5) vs 29.4 (21), p<0.001 for AA vs AG, p<0.001 for AA vs GG]. The MAE (IQR) for the weekly dose of the GWD was significantly lower compared to CWD [8.1 (10.5) vs 12.4 (12.6) (p<0.001)]. CYP2C9 and VKORC1 variants are important determinants of warfarin dose in the Arab population. The use of the genetic and clinical factors led to better warfarin dose estimation when compared to clinical factors alone. [ABSTRACT FROM AUTHOR]

Aims: The goals of this study were to develop a new technique that could pave the way for a quicker determination of CYP4F2 rs3093135 and CYP2C19 rs4244285 variants directly from a patient's blood and to attempt to apply this technique in clinical practice. Patients & methods: The study included 144 consecutive patients admitted with ST elevation myocardial infarction. A blood-direct PCR and real-time PCR were used to detect variants of interest. Results & conclusion: Patients with bleeding events had the CYP2C19 GG (*1*1) variant more frequently than patients without bleeding events. The CYP4F2 TT variant was more frequently detected in patients with bleeding events 3 months after hospitalization. Ticagrelor is one of the main antiplatelet drugs used for prevention of coronary blood clots after interventional procedures in patients with acute coronary syndromes. It has previously been shown that gene variants of CYP2C19 and CYP4F2 may affect antiplatelet therapy. This paper reports a novel instrument and the results of genetic tests obtained using this instrument. Our instrument can detect variants of the genes associated with ticagrelor antiplatelet therapy in only 40 min. These findings might facilitate individualized treatment with ticagrelor of patients with ST-elevation myocardial infarction. [ABSTRACT FROM AUTHOR]

Background Vitamin E (vitE) is hypothesized to attenuate age-related decline in pulmonary function. Objectives We investigated the association between change in plasma vitE (∆vitE) and pulmonary function decline [forced expiratory volume in the first second (FEV1)] and examined genetic and nongenetic factors associated with ∆vitE. Methods We studied 1144 men randomly assigned to vitE in SELECT (Selenium and Vitamin E Cancer Prevention Trial). ∆vitE was the difference between baseline and year 3 vitE concentrations measured with GC-MS. FEV1 was measured longitudinally by spirometry. We genotyped 555 men (vitE-only arm) using the Illumina Expanded Multi-Ethnic Genotyping Array (MEGAex). We used mixed-effects linear regression modeling to examine the ∆vitE–FEV1 association. Results Higher ∆vitE was associated with lower baseline α-tocopherol (α-TOH), higher baseline γ-tocopherol, higher baseline free cholesterol, European ancestry (as opposed to African) (all P  < 0.05), and the minor allele of a missense variant in cytochrome P450 family 4 subfamily F member 2 (CYP4F2) (rs2108622-T; 2.4 µmol/L higher ∆vitE, SE: 0.8 µmol/L; P  = 0.0032). Higher ∆vitE was associated with attenuated FEV1 decline, with stronger effects in adherent participants (≥80% of supplements consumed): a statistically significant ∆vitE × time interaction (P  = 0.014) indicated that a 1-unit increase in ∆vitE was associated with a 2.2-mL/y attenuation in FEV1 decline (SE: 0.9 mL/y). The effect size for 1 SD higher ∆vitE (+4 µmol/mmol free-cholesterol-adjusted α-TOH) was roughly one-quarter of the effect of 1 y of aging, but in the opposite direction. The ∆vitE–FEV1 association was similar in never smokers (2.4-mL/y attenuated FEV1 decline, SE: 1.0 mL/y; P  = 0.017, n  = 364), and current smokers (2.8-mL/y, SE: 1.6 mL/y; P  = 0.079, n  = 214), but there was little to no effect in former smokers (−0.64-mL/y, SE: 0.9 mL/y; P  = 0.45, n  = 564). Conclusions Greater response to vitE supplementation was associated with attenuated FEV1 decline. The response to supplementation differed by rs2108622 such that individuals with the C allele, compared with the T allele, may need a higher dietary intake to reach the same plasma vitE concentration. [ABSTRACT FROM AUTHOR]

Background: Ticagrelor belongs to a new class of P2Y12 receptor inhibitor that has been widely used for antiplatelet therapy. This study aimed to explore the effect of single nucleotide polymorphisms (SNPs) in metabolic enzymes, transporters, and other relevant variants on the pharmacokinetics (PK) of ticagrelor and its active metabolite, AR-C124910XX. Methods: The study population comprised 68 healthy Chinese volunteers who were enrolled in a ticagrelor bioequivalence clinical trial. The PK profile of ticagrelor was evaluated after orally administering a single 90-mg dose of ticagrelor in tablet form. The plasma concentrations of ticagrelor and AR-C124910XX were determined through liquid chromatography–tandem mass spectrometry. Plasma DNA samples were used to explore the effect of gene polymorphisms on the PK of ticagrelor and AR-C124910XX with whole-exome sequencing. Results: Female participants had a higher maximum plasma concentration/weight ratio (C max/ W ; p < 0.001) and a shorter half-life (T 1/2; p < 0.05) for ticagrelor than their male counterparts. In addition, a higher area under the curve/weight ratio (AUC/ W ; p < 0.001), and longer T 1/2 (p < 0.001) and time to reach the maximum plasma concentration (T max; p < 0.001), as well as a lower apparent drug clearance (CL/F; p < 0.001), were observed among healthy volunteers in the fed trial compared to those enrolled in the fasting trial. For AR-C124910XX, higher C max/ W (p < 0.001) and AUC/ W (p < 0.001) but lower CL/F (p < 0.001) and apparent volume of distribution (V d/F; p < 0.001) were observed among female participants. Healthy volunteers enrolled in the fasting trial exhibited higher C max/ W (p < 0.001) and AUC/ W (p < 0.01), shorter T max (p < 0.001), and lower CL/F (p < 0.001) and V d/F (p < 0.001) than those enrolled in the fed trial. Upon confirmation through multivariate analysis, the CYP4F2 rs2074900 A/A carriers were associated with higher C max/ W and AUC/ W and lower CL/F and V d/F than the CYP4F2 rs2074900 A/G and G/G carriers. Conclusion: This study is the first to show that the CYP4F2 rs2074900 SNP had a remarkable effect on ticagrelor PK, which is significant since it adds to the limited pharmacogenetic information on ticagrelor. [ABSTRACT FROM AUTHOR]

Abstract Background Chronic obstructive pulmonary disease (COPD) is a complex pulmonary disease. Cytochrome P450 family 4 subfamily F member 2 (CYP4F2) belongs to cytochrome P450 superfamily of enzymes responsible for metabolism, its single nucleotide polymorphisms (SNPs) were reported to be involved in metabolism in the development of many diseases. The study aimed to assess the relation between CYP4F2 SNPs and COPD risk in the Hainan Han population. Method We genotyped five SNPs in CYP4F2 in 313 cases and 508 controls by Agena MassARRAY assay. The association between CYP4F2 SNPs and COPD risk were assessed by χ2 test and genetic models. Besides, logistic regression analysis was introduced into the calculation for odds ratio (OR) and 95% confidence intervals (CIs). Results Allele model analysis indicated that rs3093203 A was significantly correlated with an increased risk of COPD. Also, rs3093193 G and rs3093110 G were associated with a reduced COPD risk. In the genetic models, we found that rs3093203 was related to an increased COPD risk, while rs3093193 and rs3093110 were related to a reduced risk of COPD. After gender stratification, rs3093203, rs3093193 and rs3093110 showed the association with COPD risk in males. With smoking stratification, rs3093144 was significantly associated with an increased risk of COPD in smokers. CYP4F2 SNPs were significantly associated with COPD risk. Conclusions Our findings illustrated potential associations between CYP4F2 polymorphisms and COPD risk. However, large-scale and well-designed studies are needed to determine conclusively the association between the CYP4F2 SNPs and COPD risk.

Background: Ticagrelor belongs to a new class of P2Y12 receptor inhibitor that has been widely used for antiplatelet therapy. This study aimed to explore the effect of single nucleotide polymorphisms (SNPs) in metabolic enzymes, transporters, and other relevant variants on the pharmacokinetics (PK) of ticagrelor and its active metabolite, AR-C124910XX.Methods: The study population comprised 68 healthy Chinese volunteers who were enrolled in a ticagrelor bioequivalence clinical trial. The PK profile of ticagrelor was evaluated after orally administering a single 90-mg dose of ticagrelor in tablet form. The plasma concentrations of ticagrelor and AR-C124910XX were determined through liquid chromatography–tandem mass spectrometry. Plasma DNA samples were used to explore the effect of gene polymorphisms on the PK of ticagrelor and AR-C124910XX with whole-exome sequencing.Results: Female participants had a higher maximum plasma concentration/weight ratio (Cmax/W; p

Interindividual variabilities between patients taking the anticoagulant rivaroxaban are a result of hepatic metabolism by CYP 450 enzymes. The objective of this study was to evaluate the impact of rivaroxaban on CYP4F2 and transcription factors' activity in HUVECs. Rivaroxaban and its metabolites were detected by UPLC-ESI-MS and UPLC-QTOF-MS. CYP4F2, HNF4α, PXR and CAR expressions were determined in HUVECs by qPCR; CYP4F2 protein concentration was determined by ELISA. Rivaroxaban metabolites (M-1, M-2, M-5, M-8, M-10, M-11 and M-18) were detected in endothelial cells' culture medium. Increasing concentrations of rivaroxaban determined lower 13-docosenamide concentrations. Rivaroxaban and dexamethasone reduced the expression of CYP4F2 when hsa-miR-24-3p—both CYP4F2 expression and CYP4F2 protein levels in HUVECs. The expression of the transcription factors HNF4α, PXR and CAR was not detected in HUVECs. [ABSTRACT FROM AUTHOR]

Purpose: As the most common subset of breast cancer (BC), estrogen receptor positive (ER+) BC accounting for 80% of cases, has become a global public health concern. The female hormone estrogen (E2) unequivocally drives ER + breast malignancies. The reasons that estrogen affects BC development has long been considered, yet further study remains to be conducted of the molecular events in the E2-estrogen receptor α (ERα) signaling pathway in ER + BC progression, especially lipid metabolism, so providing more options for tailored and individualized therapy. Our aim is to find out new targets and clinical biomarkers for ER + breast cancer treatment from the perspective of lipid metabolism., Methods: Lipid metabolomics profiling was used to examine the membrane phospholipid stimulated by E2. Clinical BC samples were used to assess the association of CYP4F2, CYP4F11 expression with clinicopathological characteristics and patient outcomes. Some inhibitors of main enzymes in AA metabolism were used combined with E2 to assess roles of CYP4F2/CYP4F11 in the progression of ER + BC. CYP4F2, CYP4F11 overexpression and knockdown BC cell lines were employed to examine the effects of CYP4F2, CYP4F11 on cellular proliferation, apoptosis and tumor growth. Western blotting, qPCR, Immunohistochemical staining and flow cytometry were also conducted to determine the underlying mechanisms related to CYP4F2, CYP4F11 function., Results: The activation of the CYP450 signaling pathway in arachidonic acid metabolism contributed to ER + BC tumorigenesis. In ER + BC, CYP4F2 and CYP4F11 overexpression induced by E2 could promote cancer cell proliferation and resistance to apoptosis by producing the metabolite 20-HETE and activating the antiapoptotic protein Bcl-2. CYP4F2 and CYP4F11 elevation correlates with poorer overall survival and disease-free survival in ER + BC patients., Conclusion: CYP4F2, CYP4F11 and their metabolite 20-HETE could serve as effective prognostic markers and attractive therapeutic targets for novel anticancer drug development about ER + BC., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 Published by Elsevier B.V.)

Abstract Background Age‐related macular degeneration (AMD) is the leading cause of blindness in the elderly individuals. The etiology of AMD includes environmental and genetic factors. Methods We aimed to determine the association between CETP (rs5882; rs708272; rs3764261; rs1800775; rs2303790), AGER (rs1800624; rs1800625), and CYP4F2 (rs1558139) gene polymorphisms and development of atrophic AMD. About 52 patients with atrophic AMD and 800 healthy control subjects were evaluated. The genotyping of single‐nucleotide polymorphisms in CETP, AGER, and CYP4F2 was carried out using the real‐time‐PCR method. Results Genetic risk models in the analysis of CETP rs5882 revealed statistically significant variables with increased risk of atrophic AMD in the codominant (p

Background. Genotypes of the cytochrome p450 isoform (CYP2C9 and CYP4F2) determine warfarin dose requirements. Frequencies of risk alleles and genotypes of CYP2C9 and CYP4F2 gene vary in different races and ethnic groups.Aim. This study analyzed the frequencies of *2, *3 alleles of CYP2C9 gene and the 1347 C>T allele of CYP4F2 gene in the Caucasians of Eastern Siberia, and compare with other populations.Materials and methods. Participants were 147 patients (Caucasians): 67 (45.58 %) man and 80 (54.42 %) women), taking warfarin for the prevention of thrombosis with a mean age of 64.74 ± 14.29 years. There were patients with atrial fibrillation – 77 (52.38 %) persons, coronary artery disease – 10 (6.80 %), pulmonary embolism – 5 (3.40 %), 15 (10.20 %) patients after implantation of an mechanical heart valve, etc. The subjects were genotyped for CYP2C9 (*1,*2,*3), and CYP4F2 (1347 C>T) by real-time polymerase chain reaction (RT-PCR) using “Pharmacogenetics Warfarin” reagent kits (DNA technology, Russia).Results. 69.4 % of Caucasians of Eastern Siberia (Russians), have two functional alleles (*1/*1) of CYP2C9 (they’re extensive/normal metabolizers), the number of intermediate metabolizers (*1/*2, *1/*3) was 29.8 % and 0.68 % of slow metabolizers (*3/*3). Homozygous carriers of two non-functional alleles *2 and *3 (*2/*2, *2/*3) were absent. Carriers of one coumarin-resistant Т-allele of CYP4F2 were 57 (38.7 %) respondents, two coumarin-resistant alleles – 10 (6.8 %) respondents.Conclusions. Frequencies of polymorphisms in the Cytochrome’s p450 genes of warfarin transformation in a European population of Eastern Siberia have no differences with other European populations of the world

Abstract Background The anticoagulation of atrial fibrillation catheter ablation during the perioperative stage does matter and should be treated with discretion. We aimed to assess impact of three important genes participating in vitamin K cycle (i.e. VKORC1 rs9923231, CYP4F2 rs2108622 and NQO1 rs1800566) on the daily stable warfarin dose requirement in Sichuan Han Chinese patients with catheter ablation of atrial fibrillation. Methods A total of 222 atrial fibrillation patients taking stable warfarin therapy after catheter ablation operation were enrolled in this study. The study population included had high (≥2) risk according to the CHA2DS2-VASc risk score. Genotypes of VKORC1 rs9923231, CYP4F2 rs2108622 and NQO1 rs1800566 were analyzed by using the polymerase chain reaction restriction fragment length polymorphism method (PCR-RFLP). Multiple linear regression analysis was applied to depict the impact of VKORC1 rs9923231, CYP4F2 rs2108622 and NQO1 rs1800566 on the daily stable warfarin dose requirement. Results Carriers of VKORC1 rs9923231 AG/GG genotypes required significantly higher warfarin dose (3.03 ± 0.28 mg/day, 7.19 mg/day, respectively) than AA carriers (2.52 ± 0.07 mg/day; P

Background. Carriership of CYP4F2*3 (rs2108622, Val433Met) allelic variant can affect antiplatelet effect of clopidogrel, thus changing efficacy and safety of its standard dose.Aim. To study the impact of carriership of at least one CYP4F2*3 allele on the risk of resistance to clopidogrel in patients with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention (PCI).Material and methods. The study enrolled 81 patients with ACS and PCI: 64 males and 17 females, mean age 63.9±10.9 years. CYP4F2 allelic variants were detected by the method of real-time polymerase chain reaction. Platelet functional activity was evaluated by a portative aggregometer – the VerifyNow P2Y12 assay.Results. Pharmacogenetic testing showed that 40 (49.4%) of ACS patients had normal genotype (CC), 38 (46.9%) patients were carriers of one associated with reduced drug metabolism allele (CT genotype), and 3 (3.7%) patients were homozygotes for T (TT genotype). Genotype and allele distribution was in the Hardy-Weinberg equilibrium (c2=2.79; p=0.095). There were no statistically significant differences in CYP4F2*3 allele frequency between patients that are resistant to clopidogrel (PRU>208) and in patients with a normal response to clopidogrel (PRU

Abstract Background Inconsistent conclusions have been reported for the genetic relationship between CYP4F2 (Cytochrome P450 Family 4 Subfamily F Member 2) polymorphisms and the susceptibility to cardiovascular and cerebrovascular diseases. Methods We performed a meta-analysis to assess the potential role of rs1558139 C/T and rs2108622 G/A polymorphisms of CYP4F2 in the risks of cardiovascular and cerebrovascular diseases. The retrieval of four databases, including PubMed, Web of Science (WOS), China National Knowledge Infrastructure (CNKI) and WANFANG DATA, was conducted. Mantel-Haenszel statistics for association test, Cochran’s Q statistic, sensitivity analysis for heterogeneity assessment, and Begg’s/Egger’s tests for publication bias evaluation were performed under allele, homozygote, heterozygote, dominant, and recessive models, respectively. Results A total of 597 articles were initially obtained by database searching, and twenty eligible articles were finally included. For rs1558139, a decreased risk of cardiovascular and cerebrovascular diseases was observed in the overall meta-analysis and in “hypertension”, “population-based” and “male” subgroups under models of T vs. C, CT vs. CC, and CT + TT vs. CC [all P values in association tests

The allele and genotype frequency distribution at polymorphic loci rs1799853 (430C>T) and rs1057910 (A1075C) of the CYP2C9 gene, rs2108622 (1347C>T) of the CYP4F2 gene, and rs9923231 (1639G>A) of the VKORC1 gene in the Buryat population was examined. The study involved 197 volunteers living in the Republic of Buryatia: 124 woman and 73 men, average age of 57.51 ± 10.88 years. Genetic typing of DNA samples was performed by polymerase chain reaction (RT-PCR). The frequency of the minor alleles *2 and *3 of the CYP2C9 gene was 2.03 and 3.05%, respectively. The frequency of the allele T of the CYP4F2 gene was 31.22%; the frequency of the allele A of the VKORC1 gene was 85.28%. The obtained results could be used in the prognosis of pharmacotherapy of warfarin in the population Buryat population. [ABSTRACT FROM AUTHOR]

Background: Age‐related macular degeneration (AMD) is the leading cause of blindness in the elderly individuals. The etiology of AMD includes environmental and genetic factors. Methods: We aimed to determine the association between CETP (rs5882; rs708272; rs3764261; rs1800775; rs2303790), AGER (rs1800624; rs1800625), and CYP4F2 (rs1558139) gene polymorphisms and development of atrophic AMD. About 52 patients with atrophic AMD and 800 healthy control subjects were evaluated. The genotyping of single‐nucleotide polymorphisms in CETP, AGER, and CYP4F2 was carried out using the real‐time‐PCR method. Results: Genetic risk models in the analysis of CETP rs5882 revealed statistically significant variables with increased risk of atrophic AMD in the codominant (p <.001), dominant (p <.001), recessive (p <.001), and additive (p <.001) models with the highest 25.4‐fold increased risk of atrophic AMD in the codominant model (p <.001). The AGER rs1800625 was associated with a highly increased risk of atrophic AMD in the codominant (p <.001), recessive (p <.001), and additive (p <.001) genetic models. Conclusion: We identified two polymorphisms with a higher risk of atrophic AMD (CETP rs5882 and AGER rs1800625). [ABSTRACT FROM AUTHOR]

This study aimed to explore whether the polymorphisms of CYP4F2 and CYP3A5 are correlated with the risk of lung cancer development. A case–control study was conducted among 510 patients with pathologically confirmed lung cancer as the case group and 504 healthy individuals as the control group. Four single-nucleotide polymorphisms of the CYP4F2 and CYP3A5 genes were genotyped, and their correlations with the risk of lung cancer were examined using Chi-square test and logistic regression analysis. Stratified analysis found that the rs3093105 and rs3093106 loci of CYP4F2 gene were significantly associated with lower risk of lung cancer (P = 0.012, OR 0.64, 95% CI 0.45–0.91). The correlation was related to patients' age and sex and pathological type of lung cancer. Similarly, the rs10242455 loci of CYP3A5 gene showed a statistical significance between the case group and the control group (P = 0.018, OR 0.71, 95% CI 0.53–0.94), which also was associated with reduced risk of squamous cell lung cancer in the dominant and additive models (dominant: OR 0.66, 95% CI 0.46–0.94, P = 0.021; additive: OR 0.71, 95% CI 0.53–0.95, P = 0.023). CYP4F2 and CYP3A5 gene polymorphisms are associated with the reduced risk of non-small cell lung cancer, and its correlation is related to patients' age and sex and pathological type of lung cancer. [ABSTRACT FROM AUTHOR]

Background: Chronic obstructive pulmonary disease (COPD) is a complex pulmonary disease. Cytochrome P450 family 4 subfamily F member 2 (CYP4F2) belongs to cytochrome P450 superfamily of enzymes responsible for metabolism, its single nucleotide polymorphisms (SNPs) were reported to be involved in metabolism in the development of many diseases. The study aimed to assess the relation between CYP4F2 SNPs and COPD risk in the Hainan Han population.Method: We genotyped five SNPs in CYP4F2 in 313 cases and 508 controls by Agena MassARRAY assay. The association between CYP4F2 SNPs and COPD risk were assessed by χ2 test and genetic models. Besides, logistic regression analysis was introduced into the calculation for odds ratio (OR) and 95% confidence intervals (CIs).Results: Allele model analysis indicated that rs3093203 A was significantly correlated with an increased risk of COPD. Also, rs3093193 G and rs3093110 G were associated with a reduced COPD risk. In the genetic models, we found that rs3093203 was related to an increased COPD risk, while rs3093193 and rs3093110 were related to a reduced risk of COPD. After gender stratification, rs3093203, rs3093193 and rs3093110 showed the association with COPD risk in males. With smoking stratification, rs3093144 was significantly associated with an increased risk of COPD in smokers. CYP4F2 SNPs were significantly associated with COPD risk.Conclusions: Our findings illustrated potential associations between CYP4F2 polymorphisms and COPD risk. However, large-scale and well-designed studies are needed to determine conclusively the association between the CYP4F2 SNPs and COPD risk. [ABSTRACT FROM AUTHOR]

Purpose: To find an association of relative expression of hsa-miR-24-3p and hsa-miR-34a-5p molecules and CYP4F2 enzyme activity in blood plasma of stable angina pectoris (AP) patients'. Materials and Methods: MiRNA gene expression analysis was performed on total RNA extracted from blood plasma, using quantitative real-time polymerase chain reaction. CYP4F2 enzyme levels were determined using commercial ELISA kit. In total, 32 AP and 15 control samples were examined. Results: The relative expression of hsa-miR-24-3p and hsa-miR-34a-5p was upregulated by 4.4 (p = 0.0001) and 3.8 (p = 0.005) -fold in AP patient's blood plasma compared to control subjects. CYP4F2 enzyme level in blood plasma were 2.1 (p = 0.001) times lower in AP patients. Circulating hsa-miR-24-3p was negatively associated with CYP4F2 enzyme level (Spearman correlation coefficient rank r= −0.32; p = 0.03). Moreover, patients that were taking atorvastatin, had 1.5 (p = 0.04) times higher hsa-miR-24-3p expression in blood plasma. Conclusions. Our data suggest that hsa-miR-24-3p might have an effect on CYP4F2 activity during atherosclerosis. [ABSTRACT FROM AUTHOR]

Interindividual variabilities between patients taking the anticoagulant rivaroxaban are a result of hepatic metabolism by CYP 450 enzymes. The objective of this study was to evaluate the impact of rivaroxaban on CYP4F2 and transcription factors’ activity in HUVECs. Rivaroxaban and its metabolites were detected by UPLC-ESI-MS and UPLC-QTOF-MS. CYP4F2, HNF4α, PXR and CAR expressions were determined in HUVECs by qPCR; CYP4F2 protein concentration was determined by ELISA. Rivaroxaban metabolites (M-1, M-2, M-5, M-8, M-10, M-11 and M-18) were detected in endothelial cells’ culture medium. Increasing concentrations of rivaroxaban determined lower 13-docosenamide concentrations. Rivaroxaban and dexamethasone reduced the expression of CYP4F2 when hsa-miR-24-3p—both CYP4F2 expression and CYP4F2 protein levels in HUVECs. The expression of the transcription factors HNF4α, PXR and CAR was not detected in HUVECs.

The objective of this study was to evaluate whether cytochrome P450 (CYP)4F2 is involved in the exposure of vitamin K1 through a drug interaction study with ketoconazole, a CYP4F2 inhibitor, and a pharmacogenetic study with CYP4F2*3. Twenty‐one participants with different CYP4F2*3 polymorphisms were enrolled (8 for *1/*1, 7 for *1/*3, and 6 for *3/*3). All participants were treated twice daily for 5 days with 200 mg of ketoconazole or placebo. Finally, a single dose of 10 mg vitamin K1 was administered, plasma levels of vitamin K1 were measured, and its pharmacokinetics was assessed. Ketoconazole elevated the plasma levels of vitamin K1 and increased the average area under the concentration‐time curve (AUCinf) and peak concentration by 41% and 40%, respectively. CYP4F2*3 polymorphism also affected plasma levels of vitamin K1 and its pharmacokinetics in a gene dose–dependent manner. The average AUCinf value was 659.8 ng·h/mL for CYP4F2*1/*1, 878.1 ng·h/mL for CYP4F2*1/*3, and 1125.2 ng·h/mL for CYP4F2*3/*3 (P =.010). This study revealed that ketoconazole and CYP4F2*3 polymorphism substantially increased the exposure of vitamin K1 in humans. These findings provide a plausible explanation for variations in warfarin dose requirements resulting from interindividual variations in vitamin K1 exposure due to CYP4F2‐related drug interactions and genetic polymorphisms. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate whether cytochrome P450 (CYP)4F2 is involved in the exposure of vitamin K1 through a drug interaction study with ketoconazole, a CYP4F2 inhibitor, and a pharmacogenetic study with CYP4F2*3. Twenty‐one participants with different CYP4F2*3 polymorphisms were enrolled (8 for *1/*1, 7 for *1/*3, and 6 for *3/*3). All participants were treated twice daily for 5 days with 200 mg of ketoconazole or placebo. Finally, a single dose of 10 mg vitamin K1 was administered, plasma levels of vitamin K1 were measured, and its pharmacokinetics was assessed. Ketoconazole elevated the plasma levels of vitamin K1 and increased the average area under the concentration‐time curve (AUCinf) and peak concentration by 41% and 40%, respectively. CYP4F2*3 polymorphism also affected plasma levels of vitamin K1 and its pharmacokinetics in a gene dose–dependent manner. The average AUCinf value was 659.8 ng·h/mL for CYP4F2*1/*1, 878.1 ng·h/mL for CYP4F2*1/*3, and 1125.2 ng·h/mL for CYP4F2*3/*3 (P =.010). This study revealed that ketoconazole and CYP4F2*3 polymorphism substantially increased the exposure of vitamin K1 in humans. These findings provide a plausible explanation for variations in warfarin dose requirements resulting from interindividual variations in vitamin K1 exposure due to CYP4F2‐related drug interactions and genetic polymorphisms. [ABSTRACT FROM AUTHOR]

Purpose: Large inter-individual differences in warfarin maintenance dose are mostly due to the effect of genetic polymorphisms in multiple genes, including vitamin K epoxide reductase complex 1 (VKORC1), cytochromes P450 2C9 (CYP2C9), and cytochrome P450 4F2 (CYP4F2). Thus, several algorithms for predicting the warfarin dose based on pharmacogenomics data with clinical characteristics have been proposed. Although these algorithms consider these genetic polymorphisms, the formulas have different coefficient values that are critical in this context. In this study, we assessed the mutual validity among these algorithms by specifically considering racial differences. Methods: Clinical data including actual warfarin dose (AWD) of 125 Japanese patients from our previous study (Eur J Clin Pharmacol 65(11):1097–1103, 2009) were used as registered data that provided patient characteristics, including age, sex, height, weight, and concomitant medications, as well as the genotypes of CYP2C9 and VKORC1. Genotyping for CYP4F2*3 was performed by the PCR method. Five algorithms that included these factors were selected from peer-reviewed articles. The selection covered four populations, Japanese, Chinese, Caucasian, and African-American, and the International Warfarin Pharmacogenetics Consortium (IWPC). Results: For each algorithm, we calculated individual warfarin doses for 125 subjects and statistically evaluated its performance. The algorithm from the IWPC had the statistically highest correlation with the AWD. Importantly, the calculated warfarin dose (CWD) using the algorithm from African-Americans was less correlated with the AWD as compared to those using the other algorithms. The integration of CYP4F2 data into the algorithm did not improve the prediction accuracy. Conclusion: The racial difference is a critical factor for warfarin dose predictions based on pharmacogenomics. [ABSTRACT FROM AUTHOR]

Objective: To investigate the association between the CYP4F2 gene rs1558139 and rs2108622 polymorphisms and hypertension. Materials and Methods: In this meta-analysis, we searched databases for case–control studies published before May 2018 examining the associations between two polymorphic sites of the CYP4F2 gene (rs1558139 and rs2108622) and hypertension. The fixed or random effects model chosen was selected according to the heterogeneity of the studies to calculate the pooled odds ratios (OR) and corresponding 95% confidence intervals (95% CI). Results: Six articles in total were analyzed in this study; three investigated the rs1558139 polymorphism and six investigated the rs2108622 polymorphism. The pooled OR and 95% CI using the dominant model for rs1558139, and both the homozygous model and the recessive model of rs2108622 were statistically significant giving values of 0.83 (0.71–0.96), 0.83 (0.71–0.98), and 1.24 (1.07–1.44), respectively. The pooled OR and 95% CI of the rs1558139 polymorphism in the subgroup analysis based on gender were 1.25 (1.08–1.45) and 0.98 (0.85–1.13), whereas the results for the rs2108622 polymorphism were 1.03 (0.86–1.24) and 0.91 (0.72–1.14). Conclusion: Our meta-analysis demonstrates that the rs1558139 and rs2108622 single nucleotide polymorphisms of the CYP4F2 gene are associated with hypertension, with a particularly strong link between the rs1558139 polymorphism in males. [ABSTRACT FROM AUTHOR]

[Display omitted] 20-Hydroxyeicosatetraenoic acid (20-HETE) is a lipid mediator and one of the major arachidonic acid metabolites whose formation is mainly catalyzed by the enzymes cytochrome P450 (CYP) 4F2 and CYP4A11. Several studies have suggested that 20-HETE is involved in the pathogenesis of renal diseases, including diabetic nephropathy and autosomal dominant polycystic kidney disease, and we previously reported compound 1 as a dual inhibitor of CYP4A11/4F2 with therapeutic potential against renal fibrosis. Subsequent studies revealed that compound 1 , the dual CYP4A11/4F2 inhibitor, however, exhibited low selectivity over another CYP4F subtype, CYP4F22, which catalyzes ω -hydroxylation of ultra-long-chain fatty acids (ULCFAs); ULCFAs are important for the formation of acylceramides, which play a role in skin barrier formation. Therefore, we sought to develop a CYP4A11/4F2 inhibitor that would show greater CYP4A11/4F2 selectivity against CYP4F22, to avoid potential dermatological side effects. We re-evaluated a series of compounds from our 20-HETE program and identified pyrazolylpyridine derivatives containing a carboxylic acid group showing only weak CYP4F22 inhibition. Subsequent optimization studies from these derivatives led to identification of compound 15 , which showed CYP4A11/4F2 inhibition with improved selectivity against CYP4F22. Compound 15 inhibited 20-HETE production in both human and rat renal microsomes and did not inhibit ω -hydroxylation of ULCFAs in human keratinocytes. Compound 15 also significantly inhibited renal 20-HETE production after oral administration. [ABSTRACT FROM AUTHOR]

Vitamin K1 (VK1) plays an important role in the modulation of bleeding disorders. It has been reported that ω-hydroxylation on the VK1 aliphatic chain is catalyzed by cytochrome P450 4F2 (CYP4F2), an enzyme responsible for the metabolism of eicosanoids. However, the mechanism of VK1 ω-hydroxylation by CYP4F2 has not been disclosed. In this study, we employed a combination of quantum mechanism (QM) calculations, homology modeling, molecular docking, molecular dynamics (MD) simulations, and combined quantum mechanism/molecular mechanism (QM/MM) calculations to investigate the metabolism profile of VK1 ω-hydroxylation. QM calculations based on the truncated VK1 model show that the energy barrier for ω-hydroxylation is about 6-25 kJ/mol higher than those at other potential sites of metabolism. However, results from the MD simulations indicate that hydroxylation at the ω-site is more favorable than at the other potential sites, which is in accordance with the experimental observation. The evaluation of MD simulations was further endorsed by the QM/MM calculation results. Our studies thus suggest that the active site residues of CYP4F2 play a determinant role in the ω-hydroxylation. Our results provide structural insights into the mechanism of VK1 ω-hydroxylation by CYP4F2 at the atomistic level and are helpful not only for characterizing the CYP4F2 functions but also for looking into the ω-hydroxylation mediated by other CYP4 enzymes.

The ideal dose of the oral anticoagulant warfarin varies widely among patients, mainly due to genetic factors. Genetic variations that impact warfarin pharmacokinetics and the vitamin K cycle are plausible candidates for being associated with warfarin dose requirements. Therefore, the aim of this study was to assess whether polymorphisms in the ABCB1 and CYP4F2 genes were associated with stable warfarin dose requirements in Brazilian patients. This retrospective study included samples from 309 individuals. Genotyping of ABCB1 c.3435C>T and CYP4F2 c.1297G>A were performed by polymerase chain reaction followed by melting curve analysis (HRM-PCR) and TaqMan® genotyping assay, respectively. Stable doses were adjusted in a linear multiple regression model for age, gender, body mass index, self-reported race, use of amiodarone, CYP2C9 (*2 and *3), VKORC1 c.1639G>A, and ABCB1 c.3435C>T or CYP4F2 c.1297G>A. By performing a univariate analysis of variance, we found that the warfarin patients who carry ABCB1 c.3435T variant alleles (CT and TT genotypes) need fewer warfarin stable doses in comparison with the individuals that are CC wild-type: 2.5 (p = 0.003) and 4.3 (p < 0.001) mg/week less, respectively, for the overall group of patients on stable anticoagulation therapeutics (n = 309); and 5.5 (p = 0.006) and 10.2 (p < 0.001) mg/week less, respectively, for the self-declared non-white stable subgroup (n = 76). No statistically significant differences in dose requirements were observed according to CYP4F2 genotypes. In conclusion, our results suggest ABCB1 c.3435C>T variant may influence warfarin dose requirements in Brazilian patients, when associated with other genotypic, demographic and clinical factors.

Antiplatelet therapy is one of the most importance in therapy of patients with injured coronary, cerebral and peripheral arteries. The standard of acute coronary syndrome patients treatment is double antiplatelet therapy: acetylsalicylic acid with P2Y12receptor blocker. Some distinguished genetic specifics might lead to the development of resistance to antiplatelet therapy with further thrombotic complications. Current review focuses on the pharmacogenetic specifics of patients than lead clopidogrel resistance.

Purpose: Interpatient variation of warfarin dose requirements may be explained by genetic variations and general and clinical factors. In this scenario, diverse population-calibrated dosing algorithms, which incorporate the main warfarin dosing influencers, have been widely proposed for predicting supposed warfarin maintenance dose, in order to prevent and reduce adverse events. The aim of the present study was to evaluate the impact of the inclusion of ABCB1 c.3435C>T and CYP4F2 c.1297G>A polymorphisms as additional covariates in a previously developed pharmacogenetic-based warfarin dosing algorithm calibrated for the Brazilian population.Methods: Two independent cohorts of patients treated with warfarin (n = 832 and n = 133) were included for derivation and replication of the algorithm, respectively. Genotyping of ABCB1 c.3435C>T and CYP4F2 c.1297G>A polymorphisms was performed by polymerase chain reaction followed by melting curve analysis and TaqMan® assay, respectively. A multiple linear regression was performed for the warfarin stable doses as a dependent variable, considering clinical, general, and genetic data as covariates.Results: The inclusion of ABCB1 and CYP4F2 polymorphisms was able to improve the algorithm’s coefficient of determination (R2) by 2.6%. In addition, the partial determination coefficients of these variants revealed that they explained 3.6% of the warfarin dose variability. We also observed a marginal improvement of the linear correlation between observed and predicted doses (from 59.7 to 61.4%).Conclusion: Although our study indicates that the contribution of the combined ABCB1 and CYP4F2 genotypes in explaining the overall variability in warfarin dose is not very large, we demonstrated that these pharmacogenomic data are statistically significant. However, the clinical relevance and cost-effective impact of incorporating additional variants in warfarin dosing algorithms should be carefully evaluated. [ABSTRACT FROM AUTHOR]

Vitamin K1 (VK1) plays an important role in the modulation of bleeding disorders. It has been reported that ω-hydroxylation on the VK1 aliphatic chain is catalyzed by cytochrome P450 4F2 (CYP4F2), an enzyme responsible for the metabolism of eicosanoids. However, the mechanism of VK1 ω-hydroxylation by CYP4F2 has not been disclosed. In this study, we employed a combination of quantum mechanism (QM) calculations, homology modeling, molecular docking, molecular dynamics (MD) simulations, and combined quantum mechanism/molecular mechanism (QM/MM) calculations to investigate the metabolism profile of VK1 ω-hydroxylation. QM calculations based on the truncated VK1 model show that the energy barrier for ω-hydroxylation is about 6-25 kJ/mol higher than those at other potential sites of metabolism. However, results from the MD simulations indicate that hydroxylation at the ω-site is more favorable than at the other potential sites, which is in accordance with the experimental observation. The evaluation of MD simulations was further endorsed by the QM/MM calculation results. Our studies thus suggest that the active site residues of CYP4F2 play a determinant role in the ω-hydroxylation. Our results provide structural insights into the mechanism of VK1 ω-hydroxylation by CYP4F2 at the atomistic level and are helpful not only for characterizing the CYP4F2 functions but also for looking into the ω-hydroxylation mediated by other CYP4 enzymes. [ABSTRACT FROM AUTHOR]

Aims: Previous trials on the effectiveness of genotype‐guided warfarin dosing vs. conventional dosing have been inconclusive. We conducted a systematic review and meta‐analysis of randomized trials comparing genotype‐guided to conventional dosing strategies. Methods: PubMed and the Cochrane Library were searched up to 23 October 2017. Results: A total of 76 and 94 entries were retrieved were retrieved from PubMed and the Cochrane Library, respectively. A total of 2626 subjects in the genotype‐guided dosing (mean age 63.3 ± 5.8 years; 46% male) and 2604 subjects in the conventional dosing (mean age 64.7 ± 6.1 years; 46% male) groups (mean follow‐up duration 64 days) from 18 trials were included. Compared with conventional dosing, genotype‐guided dosing significantly shortened the time to first therapeutic international normalized ratio (INR) (mean difference 2.6 days, standard error 0.3 days; P < 0.0001; I2 0%) and time to first stable INR (mean difference 5.9 days, standard error 2.0 days; P < 0.01; I2 94%). Genotype‐guided dosing also increased the time in therapeutic range (mean difference 3.1%, standard error 1.2%; P < 0.01; I2 80%) and reduced the risks of both excessive anticoagulation, defined as INR ≥4 [risk ratio (RR) 0.87; 95% confidence interval (CI) 0.78, 0.98; P < 0.05; I2: 0%), and bleeding (RR 0.82; 95% CI 0.69, 0.98; P < 0.05; I2 31%). No difference in thromboembolism (RR 0.84; 95% CI 0.56, 1.26; P = 0.40; I2 0%) or mortality (RR 1.16; 95% CI 0.46, 2.91; P = 0.76; I2 0%) was observed between the two groups. Conclusions: Genotype‐guided warfarin dosing offers better safety with less bleeding compared with conventional dosing strategies. No significant benefit on thromboembolism or mortality was evident. [ABSTRACT FROM AUTHOR]

The ideal dose of the oral anticoagulant warfarin varies widely among patients, mainly due to genetic factors. Genetic variations that impact warfarin pharmacokinetics and the vitamin K cycle are plausible candidates for being associated with warfarin dose requirements. Therefore, the aim of this study was to assess whether polymorphisms in the ABCB1 and CYP4F2 genes were associated with stable warfarin dose requirements in Brazilian patients. This retrospective study included samples from 309 individuals. Genotyping of ABCB1 c.3435C>T and CYP4F2 c.1297G>A were performed by polymerase chain reaction followed by melting curve analysis (HRM-PCR) and TaqMan® genotyping assay, respectively. Stable doses were adjusted in a linear multiple regression model for age, gender, bodymass index, self-reported race, use of amiodarone, CYP2C9 (*2 and *3), VKORC1 c.1639G>A, and ABCB1 c.3435C>T or CYP4F2 c.1297G>A. By performing a univariate analysis of variance, we found that the warfarin patients who carry ABCB1 c.3435T variant alleles (CT and TT genotypes) need fewer warfarin stable doses in comparison with the individuals that are CC wild-type: 2.5 (p = 0.003) and 4.3 (p < 0.001) mg/week less, respectively, for the overall group of patients on stable anticoagulation therapeutics (n = 309); and 5.5 (p = 0.006) and 10.2 (p < 0.001) mg/week less, respectively, for the self-declared non-white stable subgroup (n = 76). No statistically significant differences in dose requirements were observed according to CYP4F2 genotypes. In conclusion, our results suggest ABCB1 c.3435C>T variant may influence warfarin dose requirements in Brazilian patients, when associated with other genotypic, demographic and clinical factors. [ABSTRACT FROM AUTHOR]

Background: The anticoagulation of atrial fibrillation catheter ablation during the perioperative stage does matter and should be treated with discretion. We aimed to assess impact of three important genes participating in vitamin K cycle (i.e. VKORC1 rs9923231, CYP4F2 rs2108622 and NQO1 rs1800566) on the daily stable warfarin dose requirement in Sichuan Han Chinese patients with catheter ablation of atrial fibrillation.Methods: A total of 222 atrial fibrillation patients taking stable warfarin therapy after catheter ablation operation were enrolled in this study. The study population included had high (≥2) risk according to the CHA2DS2-VASc risk score. Genotypes of VKORC1 rs9923231, CYP4F2 rs2108622 and NQO1 rs1800566 were analyzed by using the polymerase chain reaction restriction fragment length polymorphism method (PCR-RFLP). Multiple linear regression analysis was applied to depict the impact of VKORC1 rs9923231, CYP4F2 rs2108622 and NQO1 rs1800566 on the daily stable warfarin dose requirement.Results: Carriers of VKORC1 rs9923231 AG/GG genotypes required significantly higher warfarin dose (3.03 ± 0.28 mg/day, 7.19 mg/day, respectively) than AA carriers (2.52 ± 0.07 mg/day; P < 0.001). Carriers of CYP4F2 rs2108622 CT/TT genotypes required significantly higher warfarin dose (3.38 ± 0.22 mg/day, 2.79 ± 0.19 mg/day, respectively) than CC carriers (2.41 ± 0.08 mg/day; P < 0.001). However, the warfarin dose for carriers of NQO1 rs1800566 CT/TT genotypes (2.46 ± 0.24 mg/day, 3.01 ± 0.27 mg/day, respectively) was not significantly higher than that for the CC carriers (2.33 ± 0.1 mg/day). The multiple linear regression model including genotypes and demographic characteristics, could explain 20.1% of individual variations in the daily stable warfarin dose in Sichuan Han Chinese. VKORC1 rs9923231 contributed most (15%) to the individual variations in daily stable warfarin dose, while CYP4F2 rs2108622 contributed least (3%).Conclusion: NQO1 rs1800566 is not a significant genetic factor of warfarin dose for Han Chinese, whereas VKORC1 rs9923231 and CYP4F2 rs2108622 are significant genetic factors, which could explain 15% and approximately 3% of individual variations in the daily stable warfarin dose respectively. [ABSTRACT FROM AUTHOR]

Differences in warfarin maintenance dosages based on the presence of polymorphisms in VKORC1, CYP2C9, CYP4F2, and ORM1 can be determined through dosage adjustment according to routine guidelines. Little is known about whether routine therapy could provide consensus anticoagulation control for patients with different genotypes. This study was carried out to compare anticoagulant control in patients with different genotypes. Six hundred seventy patients using warfarin according to Chinese guidelines were enrolled. Warfarin dosages and monitored international normalized ratios (INRs) were recorded. Genotypes of VKORC1 rs9923231, CYP4F2 rs2108622, CYP2C9 rs1057910, and ORM1 rs17650 polymorphisms were determined. Warfarin dosages and INR were compared between genotypes. Patients with the AGCC*F*F*1*1 polymorphism took longer than patients with the AACC*F*F*1*1 polymorphism (20 vs 5 days, P < .001) to achieve the targeted INR range. The INR values of patients with AACC*F*F*1*3 were unstable and did not enter the stable state control phase until after 35 days. The peak INR of patients with the AACC*F*F*1*3 polymorphism was exceedingly high, with some values exceeding the control range limit of 3.0. Patients with the AACC*F*S*1*1 or AACT*F*F*1*1 polymorphisms exhibited similar INR values as the patients with the AACC*F*F*1*1 polymorphism. This study found that routine medication with warfarin provides significantly different levels of anticoagulant control between patients with wild-type genotypes and patients with heterozygous polymorphism genotypes of VKORC1 rs9923231 or CYP2C9 rs1057910. Patients with heterozygous polymorphism genotypes of VKORC1 or CYP2C9 require genotype-directed therapy with warfarin to increase efficacy and safety in anticoagulant treatment. [ABSTRACT FROM AUTHOR]

CYP4F2 is an enzyme involved in the formation of 20-hydroxyeicosatetraenoic acid (20-HETE) from arachidonic acid and metabolizes vitamin K into an inactive form. Our objectives were to identify new CYP4F2 genetic variants and to characterize the functional consequences of the conversion of arachidonic acid into 20-HETE. We used direct DNA sequencing to identify a total of 20 single-nucleotide polymorphisms (SNPs) including four coding variants, A27V, R47C, P85A, and V433M, in 50 randomly selected subjects. Of these, A27V and P85A were new. Recombinant variant proteins were prepared using an Escherichia coli expression system, purified, and quantified via CO-difference spectral analysis. The conversion of arachidonic acid to 20-HETE by the coding variants was compared to that of the wild-type protein. Wild-type CYP4F2 exhibited the highest intrinsic clearance, followed by P85A, A27V, V433M, and R47C (40–65% of the wild-type value). The locations of the mutated residues in the three-dimensional protein structure were predicted by structural modeling, and the possible effects on 20-HETE synthesis discussed. In summary, we describe the allele frequency, haplotype distribution, and linkage disequilibrium of CYP4F2 and functionally analyze the CYP4F2 coding variants. Our findings suggest that individuals having the low-activity alleles of CYP4F2 may inefficiently convert arachidonic acid into 20-HETE. This may aid in our understanding of 20-HETE-related blood pressure problems and cardiovascular diseases when genotype-phenotype association studies are performed in the future. [ABSTRACT FROM AUTHOR]

Genetic polymorphisms in the gene encoding cytochrome P450 (CYP) 4F2, a vitamin K oxidase, affect stable warfarin dose requirements and time to therapeutic INR. CYP4F2 is part of the CYP4F gene cluster, which is highly polymorphic and exhibits a high degree of linkage disequilibrium, making it difficult to define causal variants. Our objective was to examine the effect of genetic variability in the CYP4F gene cluster on expression of the individual CYP4F genes and warfarin response. mRNA levels of the CYP4F gene cluster were quantified in human liver samples (n = 149) obtained from a well-characterized liver bank and fine mapping of the CYP4F gene cluster encompassing CYP4F2, CYP4F11, and CYP4F12 was performed. Genome-wide association study (GWAS) data from a prospective cohort of warfarin-treated patients (n = 711) was also analyzed for genetic variations across the CYP4F gene cluster. In addition, SNP-gene expression in human liver tissues and interactions between CYP4F genes were explored in silico using publicly available data repositories. We found that SNPs in CYP4F2, CYP4F11, and CYP4F12 were associated with mRNA expression in the CYP4F gene cluster. In particular, CYP4F2 rs2108622 was associated with increased CYP4F2 expression while CYP4F11 rs1060467 was associated with decreased CYP4F2 expression. Interestingly, these CYP4F2 and CYP4F11 SNPs showed similar effects with warfarin stable dose where CYP4F11 rs1060467 was associated with a reduction in daily warfarin dose requirement (∼1 mg/day, Pc = 0.017), an effect opposite to that previously reported with CYP4F2 (rs2108622). However, inclusion of either or both of these SNPs in a pharmacogenetic algorithm consisting of age, body mass index (BMI), gender, baseline clotting factor II level, CYP2C9∗2 rs1799853, CYP2C9∗3 rs1057910, and VKORC1 rs9923231 improved warfarin dose variability only by 0.5–0.7% with an improvement in dose prediction accuracy of ∼1–2%. Although there is complex regulation across the CYP4F gene cluster, the opposing effects between the two SNPs in the CYP4F gene cluster appear to compensate for each other and their effect on warfarin dose requirement is unlikely to be clinically significant.