Pharmacogenomics

Neuroglia Cells Transcriptomic in Brain Development, Aging and Neurodegenerative Diseases

Thu, 2023-02-23 06:00

Aging Dis. 2023 Feb 1;14(1):63-83. doi: 10.14336/AD.2022.0621. eCollection 2023 Feb 1.

ABSTRACT

Glia cells are essential for brain functioning during development, aging and disease. However, the role of astroglia plays during brain development is quite different from the role played in the adult lesioned brain. Therefore, a deeper understanding of pathomechanisms underlying astroglia activity in the aging brain and cerebrovascular diseases is essential to guide the development of new therapeutic strategies. To this end, this review provides a comparison between the transcriptomic activity of astroglia cells during development, aging and neurodegenerative diseases, including cerebral ischemia. During fetal brain development, astrocytes and microglia often affect the same developmental processes such as neuro-/gliogenesis, angiogenesis, axonal outgrowth, synaptogenesis, and synaptic pruning. In the adult brain astrocytes are a critical player in the synapse remodeling by mediating synapse elimination while microglia activity has been associated with changes in synaptic plasticity and remove cell debris by constantly sensing the environment. However, in the lesioned brain astrocytes proliferate and play essential functions with regard to energy supply to the neurons, neurotransmission and buildup of a protective scar isolating the lesion site from the surroundings. Inflammation, neurodegeneration, or loss of brain homeostasis induce changes in microglia gene expression, morphology, and function, generally referred to as "primed" microglia. These changes in gene expression are characterized by an enrichment of phagosome, lysosome, and antigen presentation signaling pathways and is associated with an up-regulation of genes encoding cell surface receptors. In addition, primed microglia are characterized by upregulation of a network of genes in response to interferon gamma. Conclusion. A comparison of astroglia cells transcriptomic activity during brain development, aging and neurodegenerative disorders might provide us with new therapeutic strategies with which to protect the aging brain and improve clinical outcome.

PMID:36818562 | PMC:PMC9937697 | DOI:10.14336/AD.2022.0621

Categories: Literature Watch

Impact of polymorphisms in <em>CYP</em> and <em>UGT</em> enzymes and <em>ABC</em> and <em>SLCO1B1</em> transporters on the pharmacokinetics and safety of desvenlafaxine

Thu, 2023-02-23 06:00

Front Pharmacol. 2023 Feb 2;14:1110460. doi: 10.3389/fphar.2023.1110460. eCollection 2023.

ABSTRACT

Venlafaxine pharmacokinetic variability and pharmacotherapy outcomes are well known to be related to CYP2D6 pharmacogenetic phenotype. In contrast, scarce pharmacogenetic information is available nowadays concerning desvenlafaxine, its active metabolite first marketed in 2012. The aim of this study was to evaluate the impact of 29 alleles in 12 candidate genes (e.g., CYP enzymes like CYP2D6, CYP3A4, or CYP2C19; ABC transporters like ABCB1; SLCO1B1; and UGT enzymes like UGT1A1) on desvenlafaxine pharmacokinetic variability and tolerability. Pharmacokinetic parameters and adverse drug reaction (ADR) incidence obtained from six bioequivalence clinical trials (n = 98) evaluating desvenlafaxine formulations (five with single dose administration and one with multiple-dose administration) were analyzed. No genetic polymorphism was related to pharmacokinetic variability or ADR incidence. Volunteers enrolled in the multiple-dose clinical trial also showed a higher incidence of ADRs, e.g., xerostomia or appetite disorders. Volunteers experiencing any ADR showed a significantly higher area under the time-concentration curve (AUC) than those not experiencing any ADR (5115.35 vs. 4279.04 ng*h/mL, respectively, p = 0.034). In conclusion, the strong dose-dependent relationship with the occurrence of ADRs confirms that the mechanism of action of desvenlafaxine is essentially dose-dependent.

PMID:36817149 | PMC:PMC9934922 | DOI:10.3389/fphar.2023.1110460

Categories: Literature Watch

Precision medicine in the treatment of pediatric cancers

Thu, 2023-02-23 06:00

Rev Med Suisse. 2023 Feb 22;19(815):380-387. doi: 10.53738/REVMED.2023.19.815.380.

ABSTRACT

Despite the progress in cure rates for pediatric cancers, several challenges remain, such as the management of diseases with poor prognosis. The efficacy of intensified chemotherapies is also accompanied by increased risks of severe acute and chronic toxicities. Thus, therapies specifically targeting tumor cells, or inhibiting oncogenic molecular aberrations, could provide more effective and less toxic treatments for pediatric cancers. Personalization of chemotherapies through pharmacogenetics and precision dosing could also improve the efficacy and toxicity of chemotherapies. In this review, we describe precision medicine strategies implemented or undergoing clinical evaluation in the treatment of pediatric cancers.

PMID:36815329 | DOI:10.53738/REVMED.2023.19.815.380

Categories: Literature Watch

Prader-Willi syndrome: Symptoms and topiramate response in light of genetics

Thu, 2023-02-23 06:00

Front Neurosci. 2023 Feb 6;17:1126970. doi: 10.3389/fnins.2023.1126970. eCollection 2023.

ABSTRACT

INTRODUCTION: Prader-Willi Syndrome (PWS) is a rare genetic condition, which affects one in 25,000 births and results in various phenotypes. It leads to a wide range of metabolic and endocrine disorders including growth delay, hypogonadism, narcolepsy, lack of satiety and compulsive eating, associated with mild to moderate cognitive impairment. Prognosis is especially determined by the complications of obesity (diabetes, cardiorespiratory diseases) and by severe behavioral disorders marked by impulsivity and compulsion. This heterogeneous clinical picture may lead to mis- or delayed diagnosis of comorbidities. Moreover, when diagnosis is made, treatment remains limited, with high interindividual differences in drug response. This may be due to the underlying genetic variability of the syndrome, which can involve several different genetic mutations, notably deletion or uniparental disomy (UPD) in a region of chromosome 15. Here, we propose to determine whether subjects with PWS differ for clinical phenotype and treatment response depending on the underlying genetic anomaly.

METHODS: We retrospectively included all 24 PWS patients who were referred to the Reference Center for Rare Psychiatric Disorders (GHU Paris Psychiatrie and Neurosciences) between November 2018 and July 2022, with either deletion (N = 8) or disomy (N = 16). The following socio-demographic and clinical characteristics were recorded: age, sex, psychiatric and non-psychiatric symptoms, the type of genetic defect, medication and treatment response to topiramate, which was evaluated in terms of eating compulsions and impulsive behaviors. We compared topiramate treatment doses and responses between PWS with deletion and those with disomy. Non-parametric tests were used with random permutations for p-value and bootstrap 95% confidence interval computations.

RESULTS: First, we found that disomy was associated with a more severe clinical phenotype than deletion. Second, we observed that topiramate was less effective and less tolerated in disomy, compared to deletion.

DISCUSSION: These results suggest that a pharmacogenomic-based approach may be relevant for the treatment of compulsions in PWS, thus highlighting the importance of personalized medicine for such complex heterogeneous disorders.

PMID:36814790 | PMC:PMC9939745 | DOI:10.3389/fnins.2023.1126970

Categories: Literature Watch

Consensus Statement on the definition and classification of metabolic hyperferritinaemia

Wed, 2023-02-22 06:00

Nat Rev Endocrinol. 2023 Feb 17:1-12. doi: 10.1038/s41574-023-00807-6. Online ahead of print.

ABSTRACT

Hyperferritinaemia is a common laboratory finding that is often associated with metabolic dysfunction and fatty liver. Metabolic hyperferritinaemia reflects alterations in iron metabolism that facilitate iron accumulation in the body and is associated with an increased risk of cardiometabolic and liver diseases. Genetic variants that modulate iron homeostasis and tissue levels of iron are the main determinants of serum levels of ferritin in individuals with metabolic dysfunction, raising the hypothesis that iron accumulation might be implicated in the pathogenesis of insulin resistance and the related organ damage. However, validated criteria for the non-invasive diagnosis of metabolic hyperferritinaemia and the staging of iron overload are still lacking, and there is no clear evidence of a benefit for iron depletion therapy. Here, we provide an overview of the literature on the relationship between hyperferritinaemia and iron accumulation in individuals with metabolic dysfunction, and on the associated clinical outcomes. We propose an updated definition and a provisional staging system for metabolic hyperferritinaemia, which has been agreed on by a multidisciplinary global panel of expert researchers. The goal is to foster studies into the epidemiology, genetics, pathophysiology, clinical relevance and treatment of metabolic hyperferritinaemia, for which we provide suggestions on the main unmet needs, optimal design and clinically relevant outcomes.

PMID:36805052 | PMC:PMC9936492 | DOI:10.1038/s41574-023-00807-6

Categories: Literature Watch

Genetic variants and enzyme activity in citidin deaminase: Relationship with capecitabine toxicity and recommendation for dose adjustment

Wed, 2023-02-22 06:00

Farm Hosp. 2023 Feb 20:S1130-6343(22)00026-5. doi: 10.1016/j.farma.2022.12.017. Online ahead of print.

ABSTRACT

OBJECTIVE: Capecitabine, an antineoplastic drug used in the treatment of breast and colon cancer, can cause severe, even fatal toxicity in some patients. The interindividual variability of this toxicity is largely due to genetic variations in target genes and enzymes of metabolism of this drug, such as thymidylate synthase and dihydropyrimidine dehydrogenase. The enzyme cytidine deaminase (CDA), involved in the activation of capecitabine, also has several variants associated with an increased risk of toxicity to treatment, although its role as a biomarker is not yet clearly defined. Therefore, our main objective is to study the association between the presence of genetic variants in CDA gen, CDA enzymatic activity and the development of severe toxicity in patients treated with capecitabine whose initial dose was adjusted based on the genetic profile of the dihydropyrimidine dehydrogenase gen (DPYD).

METHOD: Prospective multicenter observational cohort study, focused on the analysis of the genotype-phenotype association of the CDA enzyme. After the experimental phase, an algorithm will be developed to determine the dose adjustment needed to reduce the risk of treatment toxicity according to CDA genotype, developing a clinical guide for capecitabine dosing according to genetic variants in DPYD and CDA. Based on this guide, a Bioinformatics Tool will be created to generate the pharmacotherapeutic report automatically, facilitating the implementation of pharmacogenetic advice in clinical practice. This tool will be a great support in making pharmacotherapeutic decisions based on the patient's genetic profile, incorporating precision medicine into clinical routine. Once the usefulness of this tool has been validated, it will be offered free of charge to facilitate the implementation of pharmacogenetics in hospital centers and equitably benefit all patients on capecitabine treatment.

PMID:36813623 | DOI:10.1016/j.farma.2022.12.017

Categories: Literature Watch

Kinase Activity Is Not Required for G Protein-Coupled Receptor Kinase 4 Restraining mTOR Signaling during Cilia and Kidney Development

Wed, 2023-02-22 06:00

J Am Soc Nephrol. 2023 Jan 26. doi: 10.1681/ASN.0000000000000082. Online ahead of print.

ABSTRACT

BACKGROUND: G protein-coupled receptor kinase 4 (GRK4) is considered a central regulator of blood pressure through phosphorylation of renal dopaminergic receptors and subsequent modulation of sodium excretion. Several nonsynonymous genetic variants of GRK4 have been only partially linked to hypertension, although these variants demonstrate elevated kinase activity. However, some evidence suggests that function of GRK4 variants may involve more than regulation of dopaminergic receptors alone. Little is known about the effects of GRK4 on cellular signaling, and it is also unclear whether or how altered GRK4 function might affect kidney development.

METHODS: To better understand the effect of GRK4 variants on the functionality of GRK4 and GRK4's actions in cellular signaling during kidney development, we studied zebrafish, human cells, and a murine kidney spheroid model.

RESULTS: Zebrafish depleted of Grk4 develop impaired glomerular filtration, generalized edema, glomerular cysts, pronephric dilatation, and expansion of kidney cilia. In human fibroblasts and in a kidney spheroid model, GRK4 knockdown produced elongated primary cilia. Reconstitution with human wild-type GRK4 partially rescues these phenotypes. We found that kinase activity is dispensable because kinase-dead GRK4 (altered GRK4 that cannot result in phosphorylation of the targeted protein) prevented cyst formation and restored normal ciliogenesis in all tested models. Hypertension-associated genetic variants of GRK4 fail to rescue any of the observed phenotypes, suggesting a receptor-independent mechanism. Instead, we discovered unrestrained mammalian target of rapamycin signaling as an underlying cause.

CONCLUSIONS: These findings identify GRK4 as novel regulator of cilia and of kidney development independent of GRK4's kinase function and provide evidence that the GRK4 variants believed to act as hyperactive kinases are dysfunctional for normal ciliogenesis.

PMID:36810260 | DOI:10.1681/ASN.0000000000000082

Categories: Literature Watch

Equal access to pharmacogenomics testing: The ethical imperative for population-wide access in the UK NHS

Wed, 2023-02-22 06:00

Br J Clin Pharmacol. 2023 Feb 20. doi: 10.1111/bcp.15689. Online ahead of print.

NO ABSTRACT

PMID:36808131 | DOI:10.1111/bcp.15689

Categories: Literature Watch

Awareness and attitudes of oncology specialists toward dihydropyrimidine dehydrogenase testing in Saudi Arabia

Wed, 2023-02-22 06:00

Cancer Rep (Hoboken). 2023 Feb;6(2):e1704. doi: 10.1002/cnr2.1704. Epub 2022 Aug 14.

ABSTRACT

BACKGROUND: Fluoropyrimidines (FP) are among the most common class of prescribed anti-neoplastic drugs. This class has severe to moderate toxicity in around 10%-40% of those who take 5-fluorouracil (5-FU) or capecitabine for the treatment of cancer. In practice many patients with severe toxicities from FP use had dihydropyrimidine dehydrogenase (DPD) enzyme deficiency. Several studies have proposed DPD screening before treatment with 5-fluorouracil (5-FU) and capecitabine or other drugs belonging to the FP group. This study aims to assess the level of awareness and attitudes of oncology specialists in Saudi Arabia toward genetic screening for DPD prior to giving FP. This highlights the importance of health guidelines required for implementation in our health care system, as a framework to adopt testing as a regular practice in clinical care. Based on the findings in this study, guidelines have been suggested for the Middle East North Africa region.

METHODS: A cross-sectional survey study was conducted during 2021 targeting oncologists and clinical pharmacists working in the oncology departments across Saudi Arabia.

RESULTS: A total of 130 oncologists and pharmacists completed the questionnaire representing a response rate of 87%. Most of the respondents indicated that they prescribe FP in clinical practice, but 41% of respondents reported that they have never ordered a specific molecular test during their practice. Only 20% of respondents reported that they often screen for DPD deficiency prior to prescribing FP. Significantly higher rates of awareness of potential dihydropyrimidine dehydrogenase gene (DPYD) mutation were observed among respondents in governmental hospitals (81.1% vs. 47.4% in private hospitals), and among those with more years of practice (80.6% if 5 or more years of practice vs. 59.3% if less than 5 years of practice). Also, higher rates of observing the impact of DPD testing were present among respondents with a PharmD (35% vs. 11% for oncologists and 18% for other professions) and among those with 5 or more years of practice (24.6% vs. 7.7% among those with less than 5 years).

CONCLUSION: While in some institutions there is a high level of awareness among oncology specialists in Saudi Arabia regarding the effect of the potentially serious DPD enzyme deficiency as a result of gene mutations, screening for these mutations prior to prescribing FP is not a routine practice in hospitals across the country. The findings of this study should promote personalized medicine with recognition of interpatient variability via DPD testing to manage the risks of FP prescribing more effectively in the Kingdom of Saudi Arabia.

PMID:36806724 | DOI:10.1002/cnr2.1704

Categories: Literature Watch

Prostate cancer cell-platelet bidirectional signaling promotes calcium mobilization, invasion and apoptotic resistance via distinct receptor-ligand pairs

Wed, 2023-02-22 06:00

Sci Rep. 2023 Feb 17;13(1):2864. doi: 10.1038/s41598-023-29450-x.

ABSTRACT

Platelets play a crucial role in cancer and thrombosis. However, the receptor-ligand repertoire mediating prostate cancer (PCa) cell-platelet interactions and ensuing consequences have not been fully elucidated. Microvilli emanating from the plasma membrane of PCa cell lines (RC77 T/E, MDA PCa 2b) directly contacted individual platelets and platelet aggregates. PCa cell-platelet interactions were associated with calcium mobilization in platelets, and translocation of P-selectin and integrin αIIbβ3 onto the platelet surface. PCa cell-platelet interactions reciprocally promoted PCa cell invasion and apoptotic resistance, and these events were insensitive to androgen receptor blockade by bicalutamide. PCa cells were exceedingly sensitive to activation by platelets in vitro, occurring at a PCa cell:platelet coculture ratio as low as 1:10 (whereas PCa patient blood contains 1:2,000,000 per ml). Conditioned medium from cocultures stimulated PCa cell invasion but not apoptotic resistance nor platelet aggregation. Candidate transmembrane signaling proteins responsible for PCa cell-platelet oncogenic events were identified by RNA-Seq and broadly divided into 4 major categories: (1) integrin-ligand, (2) EPH receptor-ephrin, (3) immune checkpoint receptor-ligand, and (4) miscellaneous receptor-ligand interactions. Based on antibody neutralization and small molecule inhibitor assays, PCa cell-stimulated calcium mobilization in platelets was found to be mediated by a fibronectin1 (FN1)-αIIbβ3 signaling axis. Platelet-stimulated PCa cell invasion was facilitated by a CD55-adhesion G protein coupled receptor E5 (ADGRE5) axis, with contribution from platelet cytokines CCL3L1 and IL32. Platelet-stimulated PCa cell apoptotic resistance relied on ephrin-EPH receptor and lysophosphatidic acid (LPA)-LPA receptor (LPAR) signaling. Of participating signaling partners, FN1 and LPAR3 overexpression was observed in PCa specimens compared to normal prostate, while high expression of CCR1 (CCL3L1 receptor), EPHA1 and LPAR5 in PCa was associated with poor patient survival. These findings emphasize that non-overlapping receptor-ligand pairs participate in oncogenesis and thrombosis, highlighting the complexity of any contemplated clinical intervention strategy.

PMID:36806315 | DOI:10.1038/s41598-023-29450-x

Categories: Literature Watch

Gut microbiota affects sensitivity to immune-mediated isoniazid-induced liver injury

Wed, 2023-02-22 06:00

Biomed Pharmacother. 2023 Feb 17;160:114400. doi: 10.1016/j.biopha.2023.114400. Online ahead of print.

ABSTRACT

Isoniazid (INH) is a highly effective single and/or combined first-line anti-tuberculosis (anti-TB) therapy drug, and the hepatotoxicity greatly limits its clinical application. INH-induced liver injury (INH-DILI) is a typical immune-mediated idiosyncratic drug-induced liver injury. Existing mechanisms including genetic variations in drug metabolism and immune responses cannot fully explain the differences in susceptibility and sensitivity to INH-DILI, suggesting that other factors may be involved. Accumulating evidence indicates that the development and severity of immune-mediated liver injury is related to gut microbiota. In this study, INH exposure caused liver damage, immune disregulation and microbiota profile alteration. Depletion of gut microbiota ameliorated INH-DILI, and improved INH-DILI-associated immune disorder and inflammatory response. Moreover, hepatotoxicity of INH was ameliorated by fecal microbiota transplantation (FMT) from INH-treated mice. Notably, Bifidobacterium abundance was significantly associated with transaminase levels. In conclusion, our results suggested that the effect of gut microbiota on INH-DILI was related to immunity, and the difference in INH-DILI sensitivity was related to the structure of gut microbiota. Changes in the structure of gut microbiota by continuous exposure of INH resulted in the tolerance to liver injury, and probiotics such as Bifidobacterium might play an important role in INH-DILI and its "adaptation" phenomenon. This work provides novel evidence for elucidating the underlying mechanism of difference in individual's response to INH-DILI and potential approach for intervening anti-TB drug liver injury by modulating gut microbiota.

PMID:36805186 | DOI:10.1016/j.biopha.2023.114400

Categories: Literature Watch

Pharmacogenetic Testing in a 70-Year-Old Woman with Polypharmacy and Multiple Comorbidities: A Case Report

Wed, 2023-02-22 06:00

Am J Case Rep. 2023 Feb 21;24:e938850. doi: 10.12659/AJCR.938850.

ABSTRACT

BACKGROUND Comorbidities and polypharmacy are difficult to manage, as polypharmacy hinders identification and prevention of medication-related problems. Risk for adverse drug events (ADEs) can be minimized through pharmacogenomic (PGx) testing and related therapeutic adjustments. CASE REPORT A 70-year-old woman with comorbidities and medications enrolled in the Program of All-inclusive Care for the Elderly presented with left lower extremity (LLE) pain, generalized weakness, and major depressive disorder. The provider requested a medication safety review, where the clinical pharmacist-recommended PGx testing given the LLE pain and weakness while taking a statin and inconsistent INR readings taking warfarin. The pharmacist recommended switching atorvastatin to pravastatin to minimize the risk for statin-associated ADEs due to CYP3A4 inhibition and switching fluoxetine to citalopram due to uncontrolled depression/anxiety and to mitigate drug-drug interactions with carvedilol to reduce the risk of orthostatic hypotension. Recommendations were accepted and upon follow-up the patient reported minor LLE pain and improved wellbeing on citalopram. Following PGx testing, the patient had decreased function at SLCO1B1 and was an intermediate metabolizer for CYP2C9 and CYP2D6. This case demonstrates how preemptive PGx testing would have identified drug-gene interactions (DGIs) at the time of prescribing and reduced the risk of statin-associated muscular symptoms, highlighting the utility of panel-based PGx testing in older adults at high risk for ADEs and/or therapy failure. CONCLUSIONS Decreased function at SLCO1B1 increases exposure to statins, leading to statin-induced myalgias, as displayed in this case. PGx testing can help identify DGIs, choose optimal therapies in medically complex older adults, and minimize ADE risk.

PMID:36804920 | DOI:10.12659/AJCR.938850

Categories: Literature Watch

Role of Brazilian bats in the epidemiological cycle of potentially zoonotic pathogens

Wed, 2023-02-22 06:00

Microb Pathog. 2023 Feb 17:106032. doi: 10.1016/j.micpath.2023.106032. Online ahead of print.

ABSTRACT

Bats (Chiroptera) are flying mammals of great biodiversity and habits. These characteristics contribute for them being natural reservoirs and part of the epidemiological cycle of several potentially zoonotic pathogens, such as viruses, protozoa, fungi and bacteria. Brazil hosts approximately 15% of the world's bat diversity, with 181 distinct species, 68 genera and 9 families. About 60% of infectious diseases in humans are of zoonotic origin and, in the last decades, the detection of zoonotic pathogens in bats and their environment has been reported, such as Rabies virus (RABV) and Histoplasma capsulatum. Thus, the aim of this work was to review the reports of zoonotic pathogens associated with bats in Brazil in the past ten years. We reviewed the main pathogenic microorganisms described and the species of bats most frequently involved in the epidemiological cycles of these zoonotic agents. The obtained data show an upward trend in the detection of zoonotic pathogens in Brazilian bats, such as RABV, Bartonella sp., Histoplasma capsulatum and Leishmania spp., with emphasis on the bat species Artibeus lituratus, Carollia perspicillata, Desmodus rotundus and Molossus molossus. These findings highlight the importance of monitoring bat-associated microrganisms to early identify pathogens that may threaten bat populations, including potentially zoonotic microrganisms, emphasizing the importance of the One Health approach to prevent and mitigate the risks of the emergence of zoonotic diseases.

PMID:36804526 | DOI:10.1016/j.micpath.2023.106032

Categories: Literature Watch

Pharmacokinetics and pharmacogenomics of clozapine in an ancestrally diverse sample: a longitudinal analysis and genome-wide association study using UK clinical monitoring data

Tue, 2023-02-21 06:00

Lancet Psychiatry. 2023 Mar;10(3):209-219. doi: 10.1016/S2215-0366(23)00002-0.

ABSTRACT

BACKGROUND: The antipsychotic, clozapine, is the only licensed drug against the treatment-resistant symptoms that affect 20-30% of people with schizophrenia. Clozapine is markedly underprescribed, partly because of concerns about its narrow therapeutic range and adverse drug reaction profile. Both concerns are linked to drug metabolism, which varies across populations globally and is partly genetically determined. Our study aimed to use a cross-ancestry genome-wide association study (GWAS) design to investigate variations in clozapine metabolism within and between genetically inferred ancestral backgrounds, to discover genomic associations to clozapine plasma concentrations, and to assess the effects of pharmacogenomic predictors across different ancestries.

METHODS: In this GWAS, we analysed data from the UK Zaponex Treatment Access System clozapine monitoring service as part of the CLOZUK study. We included all available individuals with clozapine pharmacokinetic assays requested by their clinicians. We excluded people younger than 18 years, or whose records contained clerical errors, or with blood drawn 6-24 h after dose, a clozapine or norclozapine concentration less than 50 ng/mL, a clozapine concentration of more than 2000 ng/mL, a clozapine-to-norclozapine ratio outside of the 0·5-3·0 interval, or a clozapine dose of more than 900 mg/day. Using genomic information, we identified five biogeographical ancestries: European, sub-Saharan African, north African, southwest Asian, and east Asian. We did pharmacokinetic modelling, a GWAS, and a polygenic risk score association analysis using longitudinal regression analysis with three primary outcome variables: two metabolite plasma concentrations (clozapine and norclozapine) and the clozapine-to-norclozapine ratio.

FINDINGS: 19 096 pharmacokinetic assays were available for 4760 individuals in the CLOZUK study. After data quality control, 4495 individuals (3268 [72·7%] male and 1227 [27·3%] female; mean age 42·19 years [range 18-85]) linked to 16 068 assays were included in this study. We found a faster average clozapine metabolism in people of sub-Saharan African ancestry than in those of European ancestry. By contrast, individuals with east Asian or southwest Asian ancestry were more likely to be slow clozapine metabolisers than those with European ancestry. Eight pharmacogenomic loci were identified in the GWAS, seven with significant effects in non-European groups. Polygenic scores generated from these loci were associated with clozapine outcome variables in the whole sample and within individual ancestries; the maximum variance explained was 7·26% for the metabolic ratio.

INTERPRETATION: Longitudinal cross-ancestry GWAS can discover pharmacogenomic markers of clozapine metabolism that, individually or as polygenic scores, have consistent effects across ancestries. Our findings suggest that ancestral differences in clozapine metabolism could be considered for optimising clozapine prescription protocols for diverse populations.

FUNDING: UK Academy of Medical Sciences, UK Medical Research Council, and European Commission.

PMID:36804072 | DOI:10.1016/S2215-0366(23)00002-0

Categories: Literature Watch

Pharmacogenomics-informed clozapine therapy

Tue, 2023-02-21 06:00

Lancet Psychiatry. 2023 Mar;10(3):160-162. doi: 10.1016/S2215-0366(23)00032-9.

NO ABSTRACT

PMID:36804063 | DOI:10.1016/S2215-0366(23)00032-9

Categories: Literature Watch

Nicotine abuse and neurodegeneration: Novel pharmacogenetic targets to aid quitting and reduce the risk of dementia

Tue, 2023-02-21 06:00

CNS Neurol Disord Drug Targets. 2023 Feb 20. doi: 10.2174/1871527322666230220121655. Online ahead of print.

ABSTRACT

Nicotine dependence has deleterious neurological impacts. Previous studies found an association between cigarette smoking and accelerating age-related thinning of the brain's cortex and subsequent cognitive decline. Smoking is considered the third most common risk factor for dementia, which prompted the inclusion of smoking cessation in dementia prevention strategies. Traditional pharmacologic options for smoking cessation include nicotine transdermal patches, bupropion and varenicline. However, based on smokers' genetic makeup, pharmacogenetics can be used to develop novel therapies to replace these traditional approaches. Genetic variability of cytochrome P450 2A6 has a major impact on smokers' behavior and their response to quitting therapies. Gene polymorphism in nicotinic acetylcholine receptor subunits also has a great influence on the ability to quit smoking. In addition, polymorphism of certain nicotinic acetylcholine receptors was found to affect the risk of dementia and the impact of tobacco smoking on the development of Alzheimer's disease. Nicotine dependence involves the activation of pleasure response through the stimulation of dopamine release. Central dopamine receptors, catechol-o-methyltransferase and the dopamine transporter protein, regulate synaptic dopamine levels. The genes of these molecules are potential targets for novel smoking cessation drugs. Pharmacogenetic studies of smoking cessation also investigated other molecules, such as ANKK1 and dopamine-beta-hydroxylase (DBH). In this perspective article, we aim to highlight the promising role of pharmacogenetics in the development of effective drugs for smoking cessation, which can increase the success rate of smoking quitting plans and ultimately reduce the incidence of neurodegeneration and dementia.

PMID:36803746 | DOI:10.2174/1871527322666230220121655

Categories: Literature Watch

News in DMPT: Leaders in Pharmacogenetics Section

Tue, 2023-02-21 06:00

Drug Metab Pers Ther. 2023 Feb 20. doi: 10.1515/dmpt-2023-0004. Online ahead of print.

NO ABSTRACT

PMID:36803453 | DOI:10.1515/dmpt-2023-0004

Categories: Literature Watch

Which hematology/oncology patients are high priority for ambulatory clinical pharmacist review? A three-round Delphi survey by the National Comprehensive Cancer Network

Tue, 2023-02-21 06:00

J Oncol Pharm Pract. 2023 Feb 19:10781552231157660. doi: 10.1177/10781552231157660. Online ahead of print.

ABSTRACT

INTRODUCTION: Prioritization and acuity tools have been leveraged to facilitate targeted and efficient clinical pharmacist interventions. However, there is a lack of established pharmacy-specific acuity factors in the ambulatory hematology/oncology setting. Therefore, National Comprehensive Cancer Network's Pharmacy Directors Forum conducted a survey to establish consensus on acuity factors associated with hematology/oncology patients that are high priority for ambulatory clinical pharmacist review.

METHODS: A three-round electronic Delphi survey was conducted. During the first round, respondents were asked an open-ended question to suggest acuity factors based on their expert opinion. Respondents were then asked in the second round to agree or disagree with the compiled acuity factors, in which those with ≥75% agreement were included in the third round. The final consensus was defined as a mean score ≥3.33 on a modified 4-point Likert scale (4 = strongly agree, 1 = strongly disagree) during the third round.

RESULTS: A total of 124 hematology/oncology clinical pharmacists completed the first round of the Delphi survey (invitation response rate, 36.7%), of which 103 completed the second round (response rate, 83.1%) and 84 the third round (response rate, 67.7%). A final consensus was achieved for 18 acuity factors. Acuity factors were identified in the following themes: antineoplastic regimen characteristics, drug interactions, organ dysfunction, pharmacogenomics, recent discharge, laboratory parameters, and treatment-related toxicities.

CONCLUSIONS: This Delphi panel of 124 clinical pharmacists achieved consensus on 18 acuity factors that would identify a hematology/oncology patient as a high priority for ambulatory clinical pharmacist review. The research team envisions incorporating these acuity factors into a pharmacy-specific electronic scoring tool.

PMID:36803319 | DOI:10.1177/10781552231157660

Categories: Literature Watch

Review of genetic and pharmacogenetic differences in cytotoxic and targeted therapies for pancreatic cancer in African Americans

Tue, 2023-02-21 06:00

J Natl Med Assoc. 2023 Feb 17:S0027-9684(23)00017-2. doi: 10.1016/j.jnma.2023.01.008. Online ahead of print.

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) is currently the third leading cause of cancer mortality and the incidence is projected to increase by 2030. Despite recent advances in its treatment, African Americans have a 50-60% higher incidence and 30% higher mortality rate when compared to European Americans possibly resulting from differences in socioeconomic status, access to healthcare, and genetics. Genetics plays a role in cancer predisposition, response to cancer therapeutics (pharmacogenetics), and in tumor behavior, making some genes targets for oncologic therapeutics. We hypothesize that the germline genetic differences in predisposition, drug response, and targeted therapies also impact PDAC disparities. To demonstrate the impact of genetics and pharmacogenetics on PDAC disparities, a review of the literature was performed using PubMed with variations of the following keywords: pharmacogenetics, pancreatic cancer, race, ethnicity, African, Black, toxicity, and the FDA-approved drug names: Fluoropyrimidines, Topoisomerase inhibitors, Gemcitabine, Nab-Paclitaxel, Platinum agents, Pembrolizumab, PARP-inhibitors, and NTRK fusion inhibitors. Our findings suggest that the genetic profiles of African Americans may contribute to disparities related to FDA approved chemotherapeutic response for patients with PDAC. We recommend a strong focus on improving genetic testing and participation in biobank sample donations for African Americans. In this way, we can improve our current understanding of genes that influence drug response for patients with PDAC.

PMID:36801148 | DOI:10.1016/j.jnma.2023.01.008

Categories: Literature Watch

Functional investigation of inherited noncoding genetic variation impacting the pharmacogenomics of childhood acute lymphoblastic leukemia treatment

Fri, 2023-02-17 06:00

medRxiv. 2023 Feb 11:2023.02.10.23285762. doi: 10.1101/2023.02.10.23285762. Preprint.

ABSTRACT

Although acute lymphoblastic leukemia (ALL) is the most common childhood cancer, there is limited understanding of the contribution of inherited genetic variation on inter-individual differences in chemotherapy response. Defining genetic factors impacting therapy failure can help better predict response and identify drug resistance mechanisms. We therefore mapped inherited noncoding variants associated with chemotherapeutic drug resistance and/or treatment outcome to ALL cis -regulatory elements and investigated their gene regulatory potential and genomic connectivity using massively parallel reporter assays and promoter capture Hi-C, respectively. We identified 53 variants with reproducible allele-specific effects on transcription and high-confidence gene targets. Subsequent functional interrogation of the top variant (rs1247117) determined that it disrupted a PU.1 consensus motif and PU.1 binding affinity. Importantly, deletion of the genomic interval containing rs1247117 sensitized ALL cells to vincristine. Together, these data demonstrate that noncoding regulatory variation associated with diverse pharmacological traits harbor significant effects on allele-specific transcriptional activity and impact sensitivity to chemotherapeutic agents in ALL.

PMID:36798219 | PMC:PMC9934807 | DOI:10.1101/2023.02.10.23285762

Categories: Literature Watch

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