Very important pharmacogenes polymorphism landscape and potential clinical relevance in the Chinese Mongolian.

PURPOSE: Our study genotyped pharmacogenes in 200 individuals from Inner Mongolia Autonomous Region, China. Aim to find distinct pharmacogenomic variations among the Mongolian population and to investigate the potential clinically operable gene-drug connection and genotype-phenotype correlation of differential variation in the Mongolian population. METHODS: We sampled 61 variations of 28 genes in PharmGKB and genotyped them using Agena MassARRAY Assay. We also obtained the allele frequency and genotype distribution data of 26 populations from the 1000 Genomes Project (1000G), and then conducted comparison and statistical analysis. RESULTS: After Bonferroni correction, there were significant genotype frequency distribution differences between the Mongolian and 26 populations: PTGS2 (rs20417), NAT2 (rs1801280, rs1799929, and rs1208), ALOX5(rs2115819), and CYP2D6 (rs1065852). It was also found that the KHV showed the smallest differences from the Mongolian and the GWD showed the largest differences. Furthermore, the differences in variants might be related to the risk of non-steroidal anti-inflammatory drug use, the slow acetylation phenotype, and other pharmacological effectiveness and toxicity in the Mongolian population. CONCLUSION: Our study demonstrates different pharmacogenomic variants in the Mongolian and fills the gaps in pharmacogenomic information of the Mongolian. Our analysis of VIPs variants in the Mongolian population may contribute to the development of safer treatment regimens and the use of personalized treatment approaches.

TPMT and NUDT15 Variants Predict Discontinuation of Azathioprine for Myelotoxicity in Patients with Inflammatory Disease: Real-World Clinical Results.

Azathioprine is used frequently to treat several inflammatory conditions. However, treatment is limited by adverse events-in particular, myelotoxicity. Thiopurine-S-methyltransferase (TPMT) and nudix hydrolase-15 (NUDT15) are enzymes involved in azathioprine metabolism; variants in the genes encoding these enzymes increase the risk for azathioprine myelotoxicity. The Clinical Pharmacogenetics Implementation Consortium (CPIC) has recommended dose adjustments based on the results of TPMT and NUDT15 genotyping. However, little is known about the importance of this genetic information in routine clinical care. We hypothesized that in patients with inflammatory diseases, TPMT and NUDT15 genotype data predict the risk of discontinuing azathioprine due to myelotoxicity. This was a retrospective cohort study in 1,403 new adult azathioprine users for the management of inflammatory conditions for whom we had genetic information and clinical data. Among patients who discontinued azathioprine, we adjudicated the reason(s). Genotyping was performed using the Illumina Infinium Expanded Multi-Ethnic Genotyping Array plus custom content. We used CPIC guidelines to determine TPMT and NUDT15 metabolizer status; patients were grouped as either: (i) poor/intermediate, or (ii) normal/indeterminate metabolizers. We classified 110 patients as poor/intermediate, and 1,293 patients as normal/indeterminate metabolizers. Poor/intermediate status was associated with a higher risk for azathioprine discontinuation due to myelotoxicity compared to normal/indeterminate metabolizers (hazard ratio (HR) = 2.90, 95% confidence interval (CI): 1.58-5.31, P = 0.001). This association remained significant after adjustment for race, age at initiation, sex, primary indication, and initial daily dose of azathioprine (adjusted HR (aHR) = 2.67, 95% CI: 1.44-4.94, P = 0.002). In conclusion, TPMT and NUDT15 metabolizer status predicts discontinuation due to myelotoxicity for patients taking azathioprine for inflammatory conditions.

The role of genetic polymorphisms in STIM1 and ORAI1 for erythropoietin resistance in patients with renal failure.

ABSTRACT: Anemia is a common complication in patients with renal failure. While erythropoietin is commonly used to treat anemia, some patients exhibit a poor response to erythropoietin. Since store-operated calcium channel (SOC) signaling is one of the erythropoietin activated pathways, we aimed to investigate the association between the genetic polymorphisms of SOC signaling pathway and erythropoietin resistance in patients with renal failure.Four tagging single nucleotide polymorphisms in STIM1 and five in ORAI1 were selected in this study. Genotyping was performed with the TaqMan Allelic Discrimination assay and the association of individual tagging single nucleotide polymorphisms with erythropoietin resistance was analyzed by multivariable adjusted random intercepts model.194 patients were enrolled in this study. The mean age of participants is 68 years, and 56% were men. The mean erythropoietin resistance index was 9.04 ±â€Š4.51 U/Kg/week/g/dL. We found that patients with the AA genotype of rs1561876 in STIM1, and the CC or CT genotypes of rs6486795 in ORAI1, were associated with increased risk of erythropoietin resistance. Functional annotation of expression quantitative trait loci revealed that the AA genotype of rs1561876 in STIM1 has a relatively lower expression of ribonucleotide reductase catalytic subunit M1 in skeletal muscle, while the CC genotype of rs6486795 in ORAI1 has a relatively higher expression of ORAI1 in the whole blood and thyroid.Overall, we demonstrate a significant association between erythropoietin resistance and genetic polymorphisms of STIM1 and ORAI1. Annotation prediction revealed the importance of SOC-mediated calcium signaling for erythropoietin resistance.

Cytochrome P450 2C19 enzyme, Cytochrome P450 2C9 enzyme, and Cytochrome P450 2D6 enzyme allelic variants and its possible effect on drug metabolism: A retrospective study.

ABSTRACT: The objective of the present study was to assess the allelic variations of Cytochrome P450 (CYP) enzymes Cytochrome P450 2C19 (CYP2C19), Cytochrome P450 2C9 (CYP2C9), and Cytochrome P450 2D6 (CYP2D6) as they play a major role in drug metabolism. The interindividual genetic variabilities of these enzymes can account for different responsiveness as well as concentration fluctuations for a particular drug.During the period of 2017 to 2018 a total of 54 patients have received pharmacogenetic testing at the Department of Genetics and Molecular Medicine at Kaunas Clinics. According to the genotype-metabolic phenotypes of CYP2C19, CYP2D6, CYP2C9 enzymes patients were classified according to the guidelines by Clinical Pharmacogenetics Implementation Consortium (CPIC): normal metabolizers (NMs), intermediate metabolizers (IMs), rapid metabolizers (RMs), ultrarapid metabolizers (UMs), and poor metabolizers (PMs).CYP2C19 enzyme allelic distribution: 18 patients (33.33%) with ∗1/∗1 genotype were NMs; 14 patients (25.93%) with ∗1/∗2; ∗2/∗17 genotypes were classified as IMs; 15 patients (27.78%) possessed ∗1/∗17 genotype and were RMs; 4 patients (7.4%) had ∗17/∗17 genotype with increased enzyme activity compared with RMs, were classified as UMs; 3 patients (5.56%) had ∗2/∗2 genotype and were marked as PMs. CYP2D6 enzyme allelic distribution: 26 patients (48.148%) contained ∗1/∗1,∗2/∗2,∗1/∗2,∗1/∗41,∗2/∗41 genotypes with normal enzymatic function so were accounted as NMs; 21 patients (38.89%) with ∗1/∗5, ∗2/∗4, ∗10/∗41, ∗1/∗4, ∗1/∗3, ∗2/∗5, ∗2/∗4, ∗2/∗6 genotypes were accounted as IMs; 2 patients (3.7%) possessed ∗2XN genotype and were accounted as UMs and 5 patients (9.26%) possessed ∗4/∗5,∗4/∗10,∗4/∗9,∗4/∗41 genotypes and had non-functional enzymatic activity so were accounted as PMs; CYP2C9 enzyme allelic distribution: 44 patients (81.48%) with∗1/∗1 genotype were NMs; 10 patients (18.52%) with ∗1/∗2;∗1/∗3 genotypes were IMs.The results of our study indicate that deviations from the normal enzymatic activity is common amongst Lithuanian people and combinatory genotyping of CYP2D6, CYP2C9, and CYP2C19 has to be promoted as an advanced method because of most commonly prescribed medicines like analgesics, antihypertensive, antidepressants are metabolized by multiple pathways involving enzymes in the CYP450 family.

Drug metabolising enzyme polymorphisms and chemotherapy-related ovarian failure in young breast cancer survivors.

Cyclophosphamide is associated with chemotherapy-related ovarian failure (CROF) in breast cancer survivors, however little is known about predicting individual risks. We sought to identify genetic alleles as biomarkers for risk of CROF after cyclophosphamide treatment. One hundred fifteen premenopausal women with newly diagnosed breast cancer were genotyped for single nucleotide polymorphisms (SNPs) in genes involved in cyclophosphamide activation (CYP3A4 and CYP2C19) and detoxification (GSTP1 and GSTA1). Patients prospectively completed menstrual diaries. With median follow up of 808 days, 28% experienced CROF. Survivors homozygous for the GSTA1 minor allele had lower hazards for developing CROF (HR 0.22 [95% CI 0.05-0.94], p=.04), while survivors homozygous for the CYP2C19 minor allele had higher hazards for developing CROF (HR 4.5 [95% CI 1.5-13.4], p=.007) compared to patients with at least one major allele. In separate multivariable models adjusting for age and tamoxifen use, the associations were no longer statistically significant (GSTA1 HR 0.24 [95% CI 0.06-1.0], p=.05; CYP2C19 HR 2.5 [0.8-7.6], p=.11). CYP3A4 and GSTP1 SNPs were not significantly related to CROF. In younger breast cancer survivors undergoing cyclophosphamide-based chemotherapy, genetic variation in CYP2C19 and GSTA1 merits further study to determine its relationship with CROF.IMPACT STATEMENTWhat is already known on this subject? Young breast cancer survivors face important potential implications of chemotherapy-related ovarian failure (CROF). Little is known about individual risk for CROF. Cyclophosphamide, a particularly gonadotoxic drug commonly used in breast cancer treatment, is metabolised by various cytochrome p450 enzymes. Studies have shown genetic variation in p450 enzymes is associated with differential clinical outcomes after cyclophosphamide treatment: breast cancer patients homozygous for GSTA1 minor allele had improved overall survival; lupus patients homozygous for CYP2C19 minor allele had increased risk for CROF; and CYP3A4*1B I was associated with decreased risk for CROF.What do the results of this study add? We show a surprising opposite trend for the risk of CROF in breast cancer patients with GSTA1 and CYP2C19 variants, while we did not show a significant risk for genetic variation in CYP3A4 (which had previously been shown to have a protective effect) or GSTP1.What are the implications of these findings for clinical practice and/or further research? This study shows the complexity of genetic variation in predicting outcomes to treatment. We advocate for future replicative studies to potentially validate GSTA1 and CYP2C19 and definitively negate CYP3A4 and GSTP1 as biomarkers for risk of CROF after cyclophosphamide treatment. Understanding genetic variation in chemotherapy metabolism has the potential to individualise treatment regimens to maximise efficacy and minimise toxicity.

Therapeutic drug monitoring is useful when pharmacogenetic assessment is unavailable: case report of delusional disorder / La monitorización terapéutica de fármacos es útil cuando la evaluación farmacogenética no está disponible: caso clínico de trastorno delirante

Antipsychotic plasma levels have been extensively used in the assessment of poor treatment response, lack of adherence and adverse events in delusional disorder. It has not been used as an indicator of metabolizer status, to determine whether a delusional disorder patient is a poor, intermediate, or ultra-rapid metabolizer of antipsychotics. Pharmacogenetic probes are, of course, the right method for the latter task, but they are not readily available for clinical use. We report the case of a 46-year-old woman with delusional disorder who developed unexpected adverse effects to treatment with relatively low dose risperidone and poor symptomatic response. Blood level monitoring indicated high levels of risperidone and a high concentration-to-dose ratio, which suggested accumulation of unmetabolized risperidone. Paradoxically, extrapyramidal side effects increased when, after reducing the risperidone dose, 5 mg/day of aripiprazole was added. Consequently, the patient was switched to olanzapine 5 mg/day. Sertraline 150 mg/day was later added for comorbid depression. A complete symptomatic response was achieved. Although other factors may well have been at play, this sequence of events suggests that the patient was a slow metabolizer of CYP2D6, which metabolizes both risperidone and aripiprazole. With pharmacogenetic assessment not available, therapeutic drug monitoring helped clinicians decide on appropriate management

Los niveles plasmáticos de antipsicóticos han sido extensamente utilizados para la evaluación de la pobre respuesta terapéutica, la falta de adherencia y los eventos adversos en pacientes con trastorno delirante. No han sido frecuentemente utilizados como indicadores del estado metabólico, para determinar si un paciente con trastorno delirante es metabolizador pobre, intermedio o metabolizador ultra-rápido de antipsicóticos. Los test de farmacogenética son, por supuesto, el método más idóneo para la última tarea, pero no son fáciles de obtener para su uso clínico. Reportamos el caso de una mujer de 46 años de edad con trastorno delirante que ha desarrollado efectos adversos inesperados con el tratamiento a dosis bajas de risperidona, y una pobre respuesta clínica. La monitorización de niveles plasmáticos indicó niveles elevados de risperidona y una ratio elevada concentración-dosis, que sugirió acumulación de risperidona no adecuadamente metabolizada. Paradójicamente, los efectos secundarios se incrementaron, cuando al reducir la dosis de risperidona, se añadió aripiprazol 5mg/día. Por ello, se realizó un cambio a olanzapina 5 mg/día. Se añadió sertralina 150 mg/día posteriormente para el tratamiento de síntomas depresivos comórbidos. Se alcanzó una respuesta clínica completa. A pesar de que otros factores pudieran haber contribuido a ello, la secuencia de eventos sugiere que la paciente pudiera ser metabolizadora lenta del CYP2D6, que metaboliza risperidona y aripiprazol. En caso de no disponibilidad de tests farmacogenéticos, la monitorización de niveles plasmáticos, ayudó a los clínicos a decidir el manejo apropiado del paciente

CYP2C19 polymorphism has no correlation with the efficacy and safety of thalidomide in the treatment of immune-related bowel disease.

OBJECTIVE: To explore the relationship between hepatic cytochrome P450 2C19 (CYP2C19) gene polymorphisms and the effectiveness and safety of thalidomide in the treatment of patients with immune-related bowel disease (IRBD). METHODS: CYP2C19 variants in 79 patients treated with thalidomide were analyzed using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The clinical response and adverse events of the thalidomide treatment were recorded. The potential influences of the CYP2C19 genotype polymorphisms on the clinical efficacy and adverse events of thalidomide were then investigated. RESULTS: Altogether 79 patients with IRBD (70 with Crohn's disease, three with ulcerative colitis and six with Behcet's disease) receiving thalidomide therapy were recruited from January 2013 to February 2015 in a tertiary IBD center in China. Overall, 21.5% (17/79) of these patients had CYP2C19 poor metabolizers genotype (PM). The overall response rate and the incidence of adverse events of CYP2C19 extensive metabolizers genotype were not significantly different from that of the PM when IRBD patients were treated with thalidomide (P = 0.517 and 0.816, respectively). CONCLUSION: CYP2C19 polymorphisms do not seem to be associated with efficacy of thalidomide and the incidence of adverse events in treating IRBD.

IL1RN Variation Influences Both Disease Susceptibility and Response to Recombinant Human Interleukin-1 Receptor Antagonist Therapy in Systemic Juvenile Idiopathic Arthritis.

OBJECTIVE: To determine whether systemic juvenile idiopathic arthritis (JIA) susceptibility loci that were identified by candidate gene studies demonstrate association with systemic JIA in the largest study population assembled to date. METHODS: Single-nucleotide polymorphisms (SNPs) from 11 previously reported systemic JIA risk loci were examined for association in 9 populations, including 770 patients with systemic JIA and 6,947 controls. The effect of systemic JIA-associated SNPs on gene expression was evaluated in silico in paired whole genome and RNA sequencing data from the lymphoblastoid cell lines (LCLs) of 373 European subjects from the 1000 Genomes Project. Responses of systemic JIA-associated SNPs to anakinra treatment were evaluated in 38 US patients for whom treatment response data were available. RESULTS: We found no association between the previously reported 26 SNPs and systemic JIA. Expanded analysis of the regions containing the 26 SNPs revealed only 1 significant association: the promoter region of IL1RN (P < 1 × 10-4 ). Systemic JIA-associated SNPs correlated with IL1RN expression in LCLs, with an inverse correlation between systemic JIA risk and IL1RN expression. The presence of homozygous IL1RN high expression alleles correlated strongly with a lack of response to anakinra therapy (odds ratio 28.7 [95% confidence interval 3.2-255.8]). CONCLUSION: In our study, IL1RN was the only candidate locus associated with systemic JIA. The implicated SNPs are among the strongest known determinants of IL1RN and interleukin-1 receptor antagonist levels, linking low expression with increased systemic JIA risk. Homozygous high expression alleles predicted nonresponsiveness to anakinra therapy, making them ideal candidate biomarkers to guide systemic JIA treatment. This study is an important first step toward the personalized treatment of systemic JIA.

MAO-B and COMT Genetic Variations Associated With Levodopa Treatment Response in Patients With Parkinson's Disease.

The most commonly used Parkinson's disease (PD) treatment is the replacement of dopamine by its levodopa precursor (l-dopa). Monoamine oxidase-B (MAO-B) and catechol-o-methyl transferase (COMT) are enzymes involved in the metabolism and regulation of dopamine availability. In our study we investigated the possible relation among selected single-nucleotide polymorphisms (SNPs) in the MAO-B (rs1799836) and COMT (rs4680) genes and the therapeutic response to levodopa (l-dopa). A total of 162 Brazilian patients from the Pro-Parkinson service of Clinics Hospital of Pernambuco diagnosed with sporadic PD and treated with levodopa were enrolled. PD patients were stratified into 2 groups according to the daily levodopa dose. MAO-B and COMT SNP genotyping was conducted by polymerase chain reaction-restriction fragment length polymorphism. After multivariate analysis, we observed a significant difference between PD groups for the following variables: sex (P = .02), longer duration of disease (P = .02), longer levodopa therapy duration (P = .01), younger onset of PD (P = .01), and use of COMT inhibitor (P = .02). We observed that patients carrying MAO-B (rs1799836) A and AA genotypes and COMT (rs4680) LL genotype suffered more frequently from levodopa-induced-dyskinesia. In addition, we found an increased risk of 2.84-fold for male individuals carrying the MAO-B G allele to be treated with higher doses of levodopa (P = .04). We concluded that before beginning PD pharmacological treatment, it is important to consider the genetic variants of the MAO-B and COMT genes and the sex, reinforcing the evidence that sexual dimorphism in the genes related to dopamine metabolism might affect PD treatment.

Truncated µ-Opioid Receptors With 6 Transmembrane Domains Are Essential for Opioid Analgesia.

BACKGROUND: Most clinical opioids act through µ-opioid receptors. They effectively relieve pain but are limited by side effects, such as constipation, respiratory depression, dependence, and addiction. Many efforts have been made toward developing potent analgesics that lack side effects. Three-iodobenzoyl-6ß-naltrexamide (IBNtxA) is a novel class of opioid active against thermal, inflammatory, and neuropathic pain, without respiratory depression, physical dependence, and reward behavior. The µ-opioid receptor (OPRM1) gene undergoes extensive alternative precursor messenger ribonucleic acid splicing, generating multiple splice variants that are conserved from rodents to humans. One type of variant is the exon 11 (E11)-associated truncated variant containing 6 transmembrane domains (6TM variant). There are 5 6TM variants in the mouse OPRM1 gene, including mMOR-1G, mMOR-1M, mMOR-1N, mMOR-1K, and mMOR-1L. Gene-targeting mouse models selectively removing 6TM variants in E11 knockout (KO) mice eliminated IBNtxA analgesia without affecting morphine analgesia. Conversely, morphine analgesia is lost in an exon 1 (E1) KO mouse that lacks all 7 transmembrane (7TM) variants but retains 6TM variant expression, while IBNtxA analgesia remains intact. Elimination of both E1 and E11 in an E1/E11 double KO mice abolishes both morphine and IBNtxA analgesia. Reconstituting expression of the 6TM variant mMOR-1G in E1/E11 KO mice through lentiviral expression rescued IBNtxA but not morphine analgesia. The aim of this study was to investigate the effect of lentiviral expression of the other 6TM variants in E1/E11 KO mice on IBNtxA analgesia. METHODS: Lentiviruses expressing 6TM variants were packaged in HEK293T cells, concentrated by ultracentrifugation, and intrathecally administered 3 times. Opioid analgesia was determined using a radiant-heat tail-flick assay. Expression of lentiviral 6TM variant messenger ribonucleic acids was examined by polymerase chain reaction (PCR) or quantitative PCR. RESULTS: All the 6TM variants restored IBNtxA analgesia in the E1/E11 KO mouse, while morphine remained inactive. Expression of lentiviral 6TM variants was confirmed by PCR or quantitative PCR. IBNtxA median effective dose values determined from cumulative dose-response studies in the rescued mice were indistinguishable from wild-type animals. IBNtxA analgesia was maintained for up to 33 weeks in the rescue mice and was readily antagonized by the opioid antagonist levallorphan. CONCLUSIONS: Our study demonstrated the pharmacological relevance of mouse 6TM variants in IBNtxA analgesia and established that a common functional core of the receptors corresponding to the transmembrane domains encoded by exons 2 and 3 is sufficient for activity. Thus, 6TM variants offer potential therapeutic targets for a distinct class of analgesics that are effective against broad-spectrum pain models without many side effects associated with traditional opioids.

Impact of genetic polymorphisms determining leukocyte/neutrophil count on chemotherapy toxicity.

Neutropenia and infection are major dose-limiting side effects of chemotherapy. The risk of initial infection and subsequent complications are directly related to the depth and duration of neutropenia. Recent genome-wide association studies identified variants in DARC and CXCL2 genes, and in ORMDL3-GSDMA-CSF3 locus on chromosome 17q21 that influence white blood cell and neutrophil counts in healthy individuals. To investigate whether polymorphisms in these loci in conjunction with chemotherapy may modulate risk of treatment complications, we analyzed 21 SNPs across these genes for an association with chemotherapy-related neutropenia and infection in 286 Caucasian children with acute lymphoblastic leukemia. After correction for multiple testing, DARC polymorphism rs3027012 in 5'-UTR was associated with higher risk of low absolute phagocyte count (APC<500 and <1000 cells per microliter, P=0.001 and P<0.0005, respectively) and hospitalization due to febrile neutropenia (P=0.002). Protective effect was instead seen for DARC rs12075 A to G substitution (P=0.004). The SNP rs3859192 in the GSDMA were associated with hospitalization due to infection (P=0.004); infection was also modulated in the additive manner by the CXCL2 rs16850408 (P=0.002). This study shows for the first time that the variations in DARC, GSDMA and CXCL2 genes may play a role in the onset of chemotherapy complications.

Warfarin Pharmacogenomics in Diverse Populations.

Genotype-guided warfarin dosing algorithms are a rational approach to optimize warfarin dosing and potentially reduce adverse drug events. Diverse populations, such as African Americans and Latinos, have greater variability in warfarin dose requirements and are at greater risk for experiencing warfarin-related adverse events compared with individuals of European ancestry. Although these data suggest that patients of diverse populations may benefit from improved warfarin dose estimation, the vast majority of literature on genotype-guided warfarin dosing, including data from prospective randomized trials, is in populations of European ancestry. Despite differing frequencies of variants by race/ethnicity, most evidence in diverse populations evaluates variants that are most common in populations of European ancestry. Algorithms that do not include variants important across race/ethnic groups are unlikely to benefit diverse populations. In some race/ethnic groups, development of race-specific or admixture-based algorithms may facilitate improved genotype-guided warfarin dosing algorithms above and beyond that seen in individuals of European ancestry. These observations should be considered in the interpretation of literature evaluating the clinical utility of genotype-guided warfarin dosing. Careful consideration of race/ethnicity and additional evidence focused on improving warfarin dosing algorithms across race/ethnic groups will be necessary for successful clinical implementation of warfarin pharmacogenomics. The evidence for warfarin pharmacogenomics has a broad significance for pharmacogenomic testing, emphasizing the consideration of race/ethnicity in discovery of gene-drug pairs and development of clinical recommendations for pharmacogenetic testing.

A quantitative shRNA screen identifies ATP1A1 as a gene that regulates cytotoxicity by aurilide B.

Genome-wide RNA interference (RNAi) with pooled and barcoded short-hairpin RNA (shRNA) libraries provides a powerful tool for identifying cellular components that are relevant to the modes/mechanisms of action (MoA) of bioactive compounds. shRNAs that affect cellular sensitivity to a given compound can be identified by deep sequencing of shRNA-specific barcodes. We used multiplex barcode sequencing technology by adding sample-specific index tags to PCR primers during sequence library preparation, enabling parallel analysis of multiple samples. An shRNA library screen with this system revealed that downregulation of ATP1A1, an α-subunit of Na+/K+ ATPase, conferred significant sensitivity to aurilide B, a natural marine product that induces mitochondria-mediated apoptosis. Combined treatment with ouabain which inhibits Na+/K+ ATPase by targeting α-subunits potentiated sensitivity to aurilide B, suggesting that ATP1A1 regulates mitochondria-mediated apoptosis. Our results indicate that multiplex sequencing facilitates the use of pooled shRNA library screening for the identification of combination drug therapy targets.

Gene variants in responsiveness to clopidogrel have no impact on clinical outcomes in Chinese patients undergoing percutaneous coronary intervention - A multicenter study.

BACKGROUND: Gene variants contribute to variability in individual responsiveness to clopidogrel and influence cardiovascular outcomes in Caucasian patients with acute coronary syndrome (ACS). However, limited data is available in Asian populations. METHODS: We resequenced 14 genes in metabolizing and activity pathway of clopidogrel in 138 patients with ACS and prospectively assessed the modulating effects of 13 variants possibly related to clopidogrel efficacy on one-year cardiovascular event occurrence in 5820 ACS patients after percutaneous coronary intervention (PCI). In addition, platelet aggregation rate was measured in 1084 participants and plasma levels of active metabolite were determined in 15 patients to test whether increasing clopidogrel maintenance doses increases active metabolite exposure. RESULTS: No significant associations were found between any of the tested variants and risk of cardiovascular events (P>0.05), although CYP2C19*2 carriers had slightly higher on-treatment platelet aggregation rate and lower active metabolite exposure compared with that of non-carriers (Median [IQR] 51.49 [35.43-66.75] vs. 49.05 [32.36-63.38], P=0.012) (means±SD AUC, 22.84±5.00 vs. 35.05±12.34, P=0.008). Switching from 75mg daily clopidogrel to 150mg daily fully overcomes low exposure to clopidogrel active metabolite in CYP2C19*2 carriers (means±SD AUC, 32.35±8.65 vs. 35.05±12.34, P=0.314). CONCLUSION: Different from Caucasian populations, genetic variants have no significant influence on clinical outcomes and have much milder effects on inhibition of platelet and active clopidogrel metabolite levels in Chinese patients with ACS after PCI, an effect which could be overcome with a dose escalation to 150mg daily.

Genetic dissociation of morphine analgesia from hyperalgesia in mice.

RATIONALE: Morphine is the prototypic mu opioid, producing its analgesic actions through traditional 7 transmembrane domain (7TM) G-protein-coupled receptors generated by the mu opioid receptor gene (Oprm1). However, the Oprm1 gene undergoes extensive alternative splicing to yield three structurally distinct sets of splice variants. In addition to the full-length 7TM receptors, it produces a set of truncated variants comprised of only 6 transmembrane domains (6TM). OBJECTIVES: This study explored the relative contributions of 7TM and 6TM variants in a range of morphine actions. METHODS: Groups of male and mixed-gender wild-type and exon 11 Oprm1 knockout mice were examined in a series of behavioral assays measuring analgesia, hyperalgesia, respiration, and reward in conditioned place preference assays. RESULTS: Loss of the 6TM variants in an exon 11 knockout (E11 KO) mouse did not affect morphine analgesia, reward, or respiratory depression. However, E11 KO mice lacking 6TM variants failed to show morphine-induced hyperalgesia, developed tolerance more slowly than wild-type mice, and did not display hyperlocomotion. CONCLUSIONS: Together, our findings confirm the established role of 7TM mu receptor variants in morphine analgesia, reward, and respiratory depression, but reveal an unexpected obligatory role for 6TM variants in morphine-induced hyperalgesia and a modulatory role in morphine tolerance and dependence.

Pharmacogenetic considerations in the treatment of HIV.

After the introduction of highly active antiretroviral therapy in the 1990s, the perception of the diagnosis of HIV infection gradually shifted from a 'death sentence' to a chronic disease requiring long-term treatment. The host genetic variability has been shown to play a relevant role in both antiretroviral drugs bioavailability and adverse effects susceptibility. Knowledge about pharmacogenetics role in HIV infection treatment has largely increased over the last years, and is reviewed in the present report, as well as future perspectives for the inclusion of pharmacogenetics information in the directing of HIV infection treatment.

Pharmacogenetics of stimulant abuse liability: association of CDH13 variant with amphetamine response in a racially-heterogeneous sample of healthy young adults.

RATIONALE: A previous genome-wide association study (GWAS) in a predominately Caucasian sample of healthy young adults linked greater amphetamine-induced rewarding effects with the rs3784943 G allele of the cadherin 13 (CDH13; i.e., a cell adhesion molecule implicated in neuronal connectivity) gene. This association has not been subsequently examined, nor has it been studied in Asian populations, which may have greater frequencies of the risk allele. OBJECTIVE: The objective of this study was to examine the association of rs3784943 with amphetamine response in a racially heterogeneous sample (37 % Asian) of healthy young adults. METHODS: Participants (N = 84; 18-35 years old) genotyped for rs3784943 completed counterbalanced sessions involving 20 mg oral d-amphetamine or placebo administration. At both sessions, cardiovascular and subjective drug effects measures were collected. RESULTS: In the combined racially heterogeneous sample, amphetamine (vs. placebo) effects were significantly greater on "Feel Drug" ratings (p < 0.05) and marginally greater on "Feel High" ratings and systolic blood pressure (p < 0.10) in G/A + G/G genotypes than A/A genotypes. The G allele was more common among Asian than other racial groups. Among the subsample of Asian participants (N = 31), drug effects were significantly greater on Feel Drug (p < 0.05) and marginally greater on Feel High and heart rate (p < 0.10) among Asians with G/A + G/G (vs. A/A) genotypes. CONCLUSIONS: In concert with a previous GWAS result, this candidate gene study provides convergent evidence implicating CDH13 rs3784943 variant in d-amphetamine's drug effect profile and suggests generalization to Asian populations. CDH13 and genes coding for other cell adhesion molecules may be worthy of study in the biology of psychostimulant abuse liability.

Successful treatment with afatinib after grade 3 hepatotoxicity induced by both gefitinib and erlotinib in EGFR mutation-positive non-small cell lung cancer.

Hepatotoxicity is a major cause of the withdrawal of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) when treating EGFR mutation-positive non-small cell lung cancer (NSCLC). We report a case in which gefitinib- and elrotinib-induced severe hepatotoxicity arose in a patient with the uridine diphosphate glucuronosyltransferase isoform 1A1 (UGT1A1) and cytochrome p450 3A5 (CYP3A5) poor metabolizer phenotypes. Afatinib is not significantly metabolized by cytochrome p450-mediated pathways. We describe successful management of the patient's tumor by switching to afatinib. Evaluation of single nucleotide polymorphisms (SNPs) in metabolic enzymes might be useful to predict severe hepatotoxicity induced by EGFR-TKIs.

Influx transporter variants as predictors of cancer chemotherapy-induced toxicity: systematic review and meta-analysis.

AIM: Chemotherapeutic agents have been shown to increase lung patient survival, however their use may be limited by their serious adverse effects. We aimed to assess int impact of pharmacogenetic variation of influx transporters on inter-individual patient variation in adverse drug reactions. PATIENTS & METHODS: We conducted a meta-analysis and systemic review and identified 16 publications, totaling 1510 patients, to be eligible for review. RESULTS: Meta-analysis showed east-Asian patients expressing SLCO1B1 521T>C or 1118G>A to have a two- to fourfold increased risk of irinotecan-induced neutropenia but not diarrhea. American patients, expressing SLC19A1 IVS2(4935) G>A, were further associated with pemetrexed/gemcitabine-induced grade 3+ leukopenia. CONCLUSION: Future studies should look to robust validation of SLCO1B1 and SLC19A1 as prognostic markers in the management of lung cancer patients.

Relation of the Allelic Variants of Multidrug Resistance Gene to Agranulocytosis Associated With Clozapine.

Clozapine use is associated with leukopenia and more rarely agranulocytosis, which may be lethal. The drug and its metabolites are proposed to interact with the multidrug resistance transporter (ABCB1/MDR1) gene product, P-glycoprotein (P-gp). Among various P-glycoprotein genetic polymorphisms, nucleotide changes in exons 26 (C3435T), 21 (G2677T), and 12 (C1236T) have been implicated for changes in pharmacokinetics and pharmacodynamics of many substrate drugs. In this study, we aimed to investigate the association between these specific ABCB1 polymorphisms and clozapine-associated agranulocytosis (CAA). Ten patients with a history of CAA and 91 control patients without a history of CAA, despite 10 years of continuous clozapine use, were included. Patient recruitment and blood sample collection were conducted at the Hacettepe University Faculty of Medicine, Department of Psychiatry, in collaboration with the members of the Schizophrenia and Other Psychotic Disorders Section of the Psychiatric Association of Turkey, working in various psychiatry clinics. After DNA extraction from peripheral blood lymphocytes, genotyping was performed using polymerase chain reaction and endonuclease digestion. Patients with CAA had shorter duration of clozapine use but did not show any significant difference in other clinical, sociodemographic characteristics and in genotypic or allelic distributions of ABCB1 variants and haplotypes compared with control patients. Among the 10 patients with CAA, none carried the ABCB1 all-variant haplotype (TT-TT-TT), whereas the frequency of this haplotype was approximately 12% among the controls. Larger sample size studies and thorough genetic analyses may reveal both genetic risk and protective factors for this serious adverse event.