Pharmacogenomics

Lung Disease and Genomics.

Sat, 2018-03-03 07:12

Lung Disease and Genomics.

AACN Adv Crit Care. 2018;29(1):74-83

Authors: Wysocki K

Abstract
Research and application of genomic medicine in lung disease during the past century has clarified our understanding and focus on specific phenotypes, helping clinicians tailor treatment for individual patients. Cystic fibrosis and lung cancer have been researched extensively; specific genotypes have been instrumental in precision medicine to treat these lung diseases. Asthma and chronic obstructive pulmonary disease are more complex and heterogeneous in their pathogenesis, genotypic profile, and phenotypic expression, making treatment more difficult with increasing disease severity. This article focuses on the evolving state of the science of precision medicine in lung cancer, chronic obstructive pulmonary disease, asthma, and cystic fibrosis. The body of knowledge in lung disease is growing related to pharmacogenomics, clinical guidelines, genome editing, and approaches to genomic health that will guide clinical treatment options, reduce risk, and promote health.

PMID: 29496715 [PubMed - in process]

Categories: Literature Watch

Pharmacogenomics in Critical Care.

Sat, 2018-03-03 07:12

Pharmacogenomics in Critical Care.

AACN Adv Crit Care. 2018;29(1):36-42

Authors: Cheek D, Howington L

Abstract
Since the successful completion of the Human Genome Project in 2003, extensive genomic research has continued to alter pathophysiology at the molecular level. This research includes investigation of the specific receptors and metabolizing enzymes in drug pharmacodynamics and pharmacokinetics, specifically the cytochrome P450 system located primarily in the liver. In this article, pharmacogenomics and the role of the cytochrome P450 system in metabolism of various drugs are discussed. Specifically, drugs that are used in the critical care setting and are of clinical significance to the bedside critical care nurse are examined.

PMID: 29496712 [PubMed - in process]

Categories: Literature Watch

Genomics and Precision Medicine: Implications for Critical Care.

Sat, 2018-03-03 07:12

Genomics and Precision Medicine: Implications for Critical Care.

AACN Adv Crit Care. 2018;29(1):28-35

Authors: Kessler C

Abstract
A new paradigm for disease diagnosis and treatment is emerging that will bring about changes in health care delivery in and out of the hospital setting. Over the past several decades, genomic medicine has been one of the fastest growing fields in acute and chronic health care. This quick growth has created a lag in genomics knowledge and preparation among nurses and health care providers. Genomic medicine may lead to more precise evaluation, diagnosis, and management of selected acute care conditions. This article reviews the current state of genetic and genomics science and looks at the expanding field of genomic medicine's integration into precision medicine. The aim of this article is to raise awareness and spark further inquiry to the remarkable field of genomics and precision medicine.

PMID: 29496711 [PubMed - in process]

Categories: Literature Watch

CDX2 prognostic value in stage II/III resected colon cancer is related to CMS classification.

Sat, 2018-03-03 07:12
Related Articles

CDX2 prognostic value in stage II/III resected colon cancer is related to CMS classification.

Ann Oncol. 2017 May 01;28(5):1032-1035

Authors: Pilati C, Taieb J, Balogoun R, Marisa L, de Reyniès A, Laurent-Puig P

Abstract
Background: Caudal-type homeobox transcription factor 2 (CDX2) is involved in colon cancer (CC) oncogenesis and has been proposed as a prognostic biomarker in patients with stage II or III CC.
Patients and methods: We analyzed CDX2 expression in a series of 469 CC typed for the new international consensus molecular subtype (CMS) classification, and we confirmed results in a series of 90 CC.
Results: Here, we show that lack of CDX2 expression is only present in the mesenchymal subgroup (CMS4) and in MSI-immune tumors (CMS1) and not in CMS2 and CMS3 colon cancer. Although CDX2 expression was a globally independent prognostic factor, loss of CDX2 expression is not associated with a worse prognosis in the CMS1 group, but is highly prognostic in CMS4 patients for both relapse free and overall survival. Similarly, lack of CDX2 expression was a bad prognostic factor in MSS patients, but not in MSI.
Conclusions: Our work suggests that combination of the consensual CMS classification and lack of CDX2 expression could be a useful marker to identify CMS4/CDX2-negative patients with a very poor prognosis.

PMID: 28328000 [PubMed - indexed for MEDLINE]

Categories: Literature Watch

Translational Advances of Hydrofection by Hydrodynamic Injection.

Fri, 2018-03-02 06:32

Translational Advances of Hydrofection by Hydrodynamic Injection.

Genes (Basel). 2018 Mar 01;9(3):

Authors: Sendra L, Herrero MJ, Aliño SF

Abstract
Hydrodynamic gene delivery has proven to be a safe and efficient procedure for gene transfer, able to mediate, in murine model, therapeutic levels of proteins encoded by the transfected gene. In different disease models and targeting distinct organs, it has been demonstrated to revert the pathologic symptoms and signs. The therapeutic potential of hydrofection led different groups to work on the clinical translation of the procedure. In order to prevent the hemodynamic side effects derived from the rapid injection of a large volume, the conditions had to be moderated to make them compatible with its use in mid-size animal models such as rat, hamster and rabbit and large animals as dog, pig and primates. Despite the different approaches performed to adapt the conditions of gene delivery, the results obtained in any of these mid-size and large animals have been poorer than those obtained in murine model. Among these different strategies to reduce the volume employed, the most effective one has been to exclude the vasculature of the target organ and inject the solution directly. This procedure has permitted, by catheterization and surgical procedures in large animals, achieving protein expression levels in tissue close to those achieved in gold standard models. These promising results and the possibility of employing these strategies to transfer gene constructs able to edit genes, such as CRISPR, have renewed the clinical interest of this procedure of gene transfer. In order to translate the hydrodynamic gene delivery to human use, it is demanding the standardization of the procedure conditions and the molecular parameters of evaluation in order to be able to compare the results and establish a homogeneous manner of expressing the data obtained, as 'classic' drugs.

PMID: 29494564 [PubMed]

Categories: Literature Watch

Warfarin dosing according to the genotype-guided algorithm is most beneficial in patients with atrial fibrillation: a randomized parallel group trial.

Fri, 2018-03-02 06:32

Warfarin dosing according to the genotype-guided algorithm is most beneficial in patients with atrial fibrillation: a randomized parallel group trial.

Ther Drug Monit. 2018 Feb 27;:

Authors: Makar-Aušperger K, Krželj Cand Med K, Lovrić Benčić M, Radačić Aumiler M, Erdeljić Turk V, Božina N

Abstract
BACKGROUND: Observational studies have indicated potential benefits of CYP2C9 and VKORC1 guided dosing of warfarin but randomized clinical trials have resulted in contradictory findings. One of the reasons for contradiction may be the negligence of possible differences between warfarin indications. This study aims to determine efficacy and safety of genotype- and clinically guided dosing of warfarin in atrial fibrillation (AF), deep-vein thrombosis (DVT), and pulmonary embolism (PE) within the first five days after the introduction of therapy.
METHODS: In this single-center, single-blinded, randomized, controlled trial including patients of both sexes, ≥18 years of age, diagnosed with AF, DVT, or PE, a total of 205 consecutive patients were allocated into the group where warfarin therapy was genotype-guided (PHG), and where it was adjusted according to the clinical parameters (NPHG). Genotyping of CYP2C9*2, *3 and VKORC1 was performed using the Real-Time PCR method. The primary outcomes were the percentage of time in the therapeutic international normalized ratio (INR) (2.0-3.0) range and the percentage of patients who achieved a stable anticoagulation defined as the INR (2.0-3.0) range in at least two consecutive measurements.
RESULTS: In patients with AF, the percentage of time spent in the therapeutic range of INR was higher in the PHG group (mean=26% (SD 25.0)), than in the NPHG group (mean=14% (SD 18.6)), (Δ=12; 95% confidence interval (CI) 0-23; p=0.040). There was no significant difference in other two indications for warfarin treatment. A stable dose of warfarin was achieved in a statistically higher number of patients in the PHG group 14/30 (47%), than in the NPHG group 7/32 (22%) (OR=3.13, 95% CI 0.92-10.98; p=0.039).
CONCLUSION: CYP2C9 and VKORC1 genotype-guided dosing of warfarin may be beneficial in patients diagnosed with atrial fibrillation. There is no evidence for such conclusion in patients with DVT and PE.

PMID: 29494423 [PubMed - as supplied by publisher]

Categories: Literature Watch

The use of pharmacogenomics, epigenomics, and transcriptomics to improve childhood asthma management: Where do we stand?

Fri, 2018-03-02 06:32

The use of pharmacogenomics, epigenomics, and transcriptomics to improve childhood asthma management: Where do we stand?

Pediatr Pulmonol. 2018 Mar 01;:

Authors: Farzan N, Vijverberg SJ, Kabesch M, Sterk PJ, Maitland-van der Zee AH

Abstract
Asthma is a complex multifactorial disease and it is the most common chronic disease in children. There is a high variability in response to asthma treatment, even in patients with good adherence to maintenance treatment, and a correct inhalation technique. Distinct underlying disease mechanisms in childhood asthma might be the reason of this heterogeneity. A deeper knowledge of the underlying molecular mechanisms of asthma has led to the recent development of advanced and mechanism-based treatments such as biologicals. However, biologicals are recommended only for patients with specific asthma phenotypes who remain uncontrolled despite high dosages of conventional asthma treatment. One of the main unmet needs in their application is lack of clinically available biomarkers to individualize pediatric asthma management and guide treatment. Pharmacogenomics, epigenomics, and transcriptomics are three omics fields that are rapidly advancing and can provide tools to identify novel asthma mechanisms and biomarkers to guide treatment. Pharmacogenomics focuses on variants in the DNA, epigenomics studies heritable changes that do not involve changes in the DNA sequence but lead to alteration of gene expression, and transcriptomics investigates gene expression by studying the complete set of mRNA transcripts in a cell or a population of cells. Advances in high-throughput technologies and statistical tools together with well-phenotyped patient inclusion and collaborations between different centers will expand our knowledge of underlying molecular mechanisms involved in disease onset and progress. Furthermore, it could help to select and stratify appropriate therapeutic strategies for subgroups of patients and hopefully bring precision medicine to daily practice.

PMID: 29493882 [PubMed - as supplied by publisher]

Categories: Literature Watch

The mutational landscape of MYCN, Lin28b and ALKF1174L driven murine neuroblastoma mimics human disease.

Fri, 2018-03-02 06:32
Related Articles

The mutational landscape of MYCN, Lin28b and ALKF1174L driven murine neuroblastoma mimics human disease.

Oncotarget. 2018 Feb 02;9(9):8334-8349

Authors: De Wilde B, Beckers A, Lindner S, Kristina A, De Preter K, Depuydt P, Mestdagh P, Sante T, Lefever S, Hertwig F, Peng Z, Shi LM, Lee S, Vandermarliere E, Martens L, Menten B, Schramm A, Fischer M, Schulte J, Vandesompele J, Speleman F

Abstract
Genetically engineered mouse models have proven to be essential tools for unraveling fundamental aspects of cancer biology and for testing novel therapeutic strategies. To optimally serve these goals, it is essential that the mouse model faithfully recapitulates the human disease. Recently, novel mouse models for neuroblastoma have been developed. Here, we report on the further genomic characterization through exome sequencing and DNA copy number analysis of four of the currently available murine neuroblastoma model systems (ALK, Th-MYCN, Dbh-MYCN and Lin28b). The murine tumors revealed a low number of genomic alterations - in keeping with human neuroblastoma - and a positive correlation of the number of genetic lesions with the time to onset of tumor formation was observed. Gene copy number alterations are the hallmark of both murine and human disease and frequently affect syntenic genomic regions. Despite low mutational load, the genes mutated in murine disease were found to be enriched for genes mutated in human disease. Taken together, our study further supports the validity of the tested mouse models for mechanistic and preclinical studies of human neuroblastoma.

PMID: 29492199 [PubMed]

Categories: Literature Watch

Comparison of TPMT and NUDT15 polymorphisms in Chinese patients with inflammatory bowel disease.

Fri, 2018-03-02 06:32
Related Articles

Comparison of TPMT and NUDT15 polymorphisms in Chinese patients with inflammatory bowel disease.

World J Gastroenterol. 2018 Feb 28;24(8):941-948

Authors: Wang HH, He Y, Wang HX, Liao CL, Peng Y, Tao LJ, Zhang W, Yang HX

Abstract
AIM: To observe gene polymorphisms of TPMT and NUDT15, and compare their predictive value for azathioprine (AZA)-induced leukopenia in inflammatory bowel disease (IBD).
METHODS: This study enrolled 219 patients diagnosed with IBD in Xiangya Hospital, Central South University, Changsha, China from February 2016 to November 2017. Peripheral blood of all patients was collected to detect their genotypes of TPMT and NUDT15 by pyrosequencing at the Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Xiangya Hospital. Eighty patients were treated with AZA according to the disease condition. During the first month, patients who received AZA underwent routine blood tests and liver function tests once a week. The endpoint of the study was leukopenia induced by AZA. By analyzing patient characteristics, genotypes and leukopenia induced by drug use, we found the risk factors associated with AZA-induced leukopenia.
RESULTS: There were 219 patients with IBD (160 men and 59 women), including 39 who were confirmed with ulcerative colitis (UC), 176 with Crohn's disease (CD) and 4 with undetermined IBD (UIBD). There were 44 patients (20.1%) with mutant genotype of NUDT15 (C/T); among them, 16 received AZA, and 8 (50%) developed leukopenia. There were 175 patients (79.7%) with wild genotype of NUDT15 (C/C); among them, 64 received AZA, and 11 (17.2%) developed leukopenia. A significant difference was found between NUDT15 C/T and its wild-type C/C (P = 0.004). There were only 3 patients with TPMT mutant genotype of A/G (1.4%) who participated in the research, and 1 of them was treated with AZA and developed leukopenia. The remaining 216 patients (98.6%) were found to bear the wild genotype of TPMT (A/A); among them, 79 patients received AZA, and 18 (22.8%) developed leukopenia, and there was no significant difference from those with A/G (P = 0.071). The frequency of TPMT mutation was 1.4%, and NUDT15 mutation rate was significantly higher and reached 20.1% (P = 0.000). Therefore, NUDT15 gene polymorphism was obviously a better biomarker than TPMT gene polymorphism in the prediction of AZA-induced leukopenia.
CONCLUSION: Mutation rate of NUDT15 in Chinese IBD patients is higher than that of TPMT. NUDT15 polymorphism is a better predictor for AZA-induced leukopenia than TPMT polymorphism.

PMID: 29491687 [PubMed - in process]

Categories: Literature Watch

COX2/PTGS2 Expression Is Predictive of Response to Neoadjuvant Celecoxib in HER2-negative Breast Cancer Patients.

Fri, 2018-03-02 06:32
Related Articles

COX2/PTGS2 Expression Is Predictive of Response to Neoadjuvant Celecoxib in HER2-negative Breast Cancer Patients.

Anticancer Res. 2018 Mar;38(3):1485-1490

Authors: DE Cremoux P, Hamy AS, Lehmann-Che J, Scott V, Sigal B, Mathieu MC, Bertheau P, Guinebretière JM, Pierga JY, Giacchetti S, Brain E, Marty M, Asselain B, Spyratos F, Bièche I

Abstract
BACKGROUND: The prognostic and predictive role of cyclo-oxygenase-2 (COX2) in breast cancer is still debated, and in particular, its role as a target of COX2 inhibitor (celecoxib) in neoadjuvant setting.
MATERIALS AND METHODS: We analyzed a series of 156 breast cancer samples from patients of the COX2 inhibitor-treated arm included in the REMAGUS-02 randomized phase II trial. COX2 gene expression was assessed by reverse transcription and quantitative polymerase chain reaction using ribonucleic acid from frozen biopsies. Pathological complete response (pCR) was the surrogate end-point.
RESULTS: Significantly higher rates of grade 3, and estrogen and progesterone receptor negativity were observed in tumors with the highest expression of COX2. pCR rates were significantly higher in COX2-overexpressing tumors in patients receiving celecoxib. The test for interaction between COX2 gene expression and the celecoxib effect was statistically significant (p<0.01), but was not retained in the multivariate analysis.
CONCLUSION: COX2 overexpression is predictive of pCR in patients with celecoxib-treated tumors. The efficacy of celecoxib in breast cancer might be improved by quantification of COX2 gene expression.

PMID: 29491076 [PubMed - in process]

Categories: Literature Watch

Cardiovascular disease and diabetes in patients with African or Asian background.

Fri, 2018-03-02 06:32
Related Articles

Cardiovascular disease and diabetes in patients with African or Asian background.

Tidsskr Nor Laegeforen. 2017 11 28;137(22):

Authors: Aambø A, Klemsdal TO

Abstract
BACKGROUND: Population groups of different ancestry appear to have varying prevalence of diabetes, different risks of developing cardiovascular disease and different responses to certain drugs that are used for these conditions. We wished to review the literature in this field.
MATERIAL AND METHOD: We have performed searches in several databases for systematic review articles published from the year 2000 onwards, and supplemented these with articles from reference lists, our own literature archives and a pyramid search in the Norwegian Electronic Health Library database. Altogether 37 articles were included.
RESULTS: With regard to diagnosed diabetes, the prevalence of coronary heart disease and stroke varies among groups of South Asian, East Asian, African and European ancestry. In patients of South Asian ancestry, the risk of coronary heart disease appears to be twice that of Europeans, and the disease occurs 5–10 years earlier. The prevalence of stroke is especially high in persons of African ancestry. Risk factors such as dyslipidemia and hypertension are distributed differently among these groups. The therapeutic response to drugs such as beta blockers, ACE inhibitors and various statins differs; for example, statin doses in Asians may often be halved in relation to those used for Caucasians, and ACE inhibitors are not recommended as monotherapy for hypertension in persons of African ancestry. These differences are partly attributable to variations in genetic disposition.
INTERPRETATION: The findings are clinically significant – better insight in this field enables optimal tailoring of treatment for each patient, with more rapid achievement of goals and reduced risk of adverse effects. The recommendations given in this article are consistent with and complement the Directorate of Health’s revised guidelines for the treatment of diabetes.

PMID: 29181932 [PubMed - indexed for MEDLINE]

Categories: Literature Watch

S. aureus Evades Macrophage Killing through NLRP3-Dependent Effects on Mitochondrial Trafficking.

Thu, 2018-03-01 09:02

S. aureus Evades Macrophage Killing through NLRP3-Dependent Effects on Mitochondrial Trafficking.

Cell Rep. 2018 Feb 27;22(9):2431-2441

Authors: Cohen TS, Boland ML, Boland BB, Takahashi V, Tovchigrechko A, Lee Y, Wilde AD, Mazaitis MJ, Jones-Nelson O, Tkaczyk C, Raja R, Stover CK, Sellman BR

Abstract
Clinical severity of Staphylococcus aureus respiratory infection correlates with alpha toxin (AT) expression. AT activates the NLRP3 inflammasome; deletion of Nlrp3, or AT neutralization, protects mice from lethal S. aureus pneumonia. We tested the hypothesis that this protection is not due to a reduction in inflammasome-dependent cytokines (IL-1β/IL-18) but increased bactericidal function of macrophages. In vivo, neutralization of AT or NLRP3 improved bacterial clearance and survival, while blocking IL-1β/IL-18 did not. Primary human monocytes were used in vitro to determine the mechanism through which NLRP3 alters bacterial killing. In cells treated with small interfering RNA (siRNA) targeting NLRP3 or infected with AT-null S. aureus, mitochondria co-localize with bacterial-containing phagosomes. Mitochondrial engagement activates caspase-1, a process dependent on complex II of the electron transport chain, near the phagosome, promoting its acidification. These data demonstrate a mechanism utilized by S. aureus to sequester itself from antimicrobial processes within the cell.

PMID: 29490278 [PubMed - in process]

Categories: Literature Watch

Allelic variant in the glucagon-like peptide 1 receptor gene associated with greater effect of liraglutide and exenatide on gastric emptying: A pilot pharmacogenetics study.

Thu, 2018-03-01 09:02

Allelic variant in the glucagon-like peptide 1 receptor gene associated with greater effect of liraglutide and exenatide on gastric emptying: A pilot pharmacogenetics study.

Neurogastroenterol Motil. 2018 Feb 28;:

Authors: Chedid V, Vijayvargiya P, Carlson P, Van Malderen K, Acosta A, Zinsmeister A, Camilleri M

Abstract
BACKGROUND: Weight loss in response to the long-acting GLP-1 receptor (GLP1R) analog, liraglutide, is correlated with delay in gastric-emptying (GE). The aim of this pilot study was to assess whether specific genetic variants in GLP1R or TCF7L2 are associated with delayed GE and weight loss in obese patients treated with liraglutide or the short-acting GLP-1 agonist, exenatide.
METHODS: We evaluated in obese individuals the associations of genetic variations of GLP1R (rs6923761) and TCF7L2 (rs7903146) on GE T1/2 and weight from two trials that evaluated separately exenatide, 5 μg BID for 30 days, or liraglutide, 3 mg daily for 5 weeks. Data were analyzed using the dominant genetic model and intention-to-treat analysis.
KEY RESULTS: There was a significant correlation between changes in weight and GE T1/2 (rs  = -.382, P = .004). GLP1R rs6923761 minor allele A (AA_AG) carriers who received either exenatide or liraglutide had greater delay in GE T1/2 relative to baseline (117.9 ± 27.5 [SEM] minutes and 128.9 ± 38.32 minutes) compared to GG genotype (95.8 ± 30.4 minutes and 61.4 ± 21.4 minutes, respectively; P = .11). There was a non-significant difference in weight loss based on GLP1R rs6923761 genotype after 5 weeks of treatment. There were no significant correlations with TCF7L2 (rs7903146) genotype.
CONCLUSIONS & INFERENCES: The minor A allele of GLP1R (rs6923761) is associated with greater delay in GE T1/2 in response to liraglutide and exenatide. These studies provide data to plan pharmacogenetics testing of the hypothesis that GLP1R (rs6923761) influences weight loss in response to GLP1R agonists.

PMID: 29488276 [PubMed - as supplied by publisher]

Categories: Literature Watch

Managing Bardet-Biedl Syndrome-Now and in the Future.

Thu, 2018-03-01 09:02

Managing Bardet-Biedl Syndrome-Now and in the Future.

Front Pediatr. 2018;6:23

Authors: Forsythe E, Kenny J, Bacchelli C, Beales PL

Abstract
Bardet-Biedl syndrome is a rare autosomal recessive multisystem disorder caused by defects in genes encoding for proteins that localize to the primary cilium/basal body complex. Twenty-one disease-causing genes have been identified to date. It is one of the most well-studied conditions in the family of diseases caused by defective cilia collectively known as ciliopathies. In this review, we provide an update on diagnostic developments, clinical features, and progress in the management of Bardet-Biedl syndrome. Advances in diagnostic technologies including exome and whole genome sequencing are expanding the spectrum of patients who are diagnosed with Bardet-Biedl syndrome and increasing the number of cases with diagnostic uncertainty. As a result of the diagnostic developments, a small number of patients with only one or two clinical features of Bardet-Biedl syndrome are being diagnosed. Our understanding of the syndrome-associated renal disease has evolved and is reviewed here. Novel interventions are developing at a rapid pace and are explored in this review including genetic therapeutics such as gene therapy, exon skipping therapy, nonsense suppression therapy, and gene editing. Other non-genetic therapies such as gene repurposing, targeted therapies, and non-pharmacological interventions are also discussed.

PMID: 29487844 [PubMed]

Categories: Literature Watch

DPYD and UGT1A1 genotyping to predict adverse events during first-line FOLFIRI or FOLFOXIRI plus bevacizumab in metastatic colorectal cancer.

Thu, 2018-03-01 09:02

DPYD and UGT1A1 genotyping to predict adverse events during first-line FOLFIRI or FOLFOXIRI plus bevacizumab in metastatic colorectal cancer.

Oncotarget. 2018 Jan 30;9(8):7859-7866

Authors: Cremolini C, Del Re M, Antoniotti C, Lonardi S, Bergamo F, Loupakis F, Borelli B, Marmorino F, Citi V, Cortesi E, Moretto R, Ronzoni M, Tomasello G, Zaniboni A, Racca P, Buonadonna A, Allegrini G, Ricci V, Di Donato S, Zagonel V, Boni L, Falcone A, Danesi R

Abstract
Our study addresses the issue of the clinical reliability of three candidate DPYD and one UGT single nucleotide polymorphisms in predicting 5-fluorouracil- and irinotecan-related adverse events. To this purpose, we took advantage of a large cohort of metastatic colorectal cancer patients treated with first-line 5-fluorouracil- and irinotecan-based chemotherapy regimens (i.e., FOLFIRI or FOLFOXIRI) plus bevacizumab in the randomized clinical trial TRIBE by GONO (clinicaltrials.gov: NCT00719797), in which adverse events were carefully and prospectively collected at each treatment cycle. Here we show that patients bearing DPYD c.1905+1G/A and c.2846A/T genotypes, together with UGT1A1*28 variant carriers, have an increased risk of experiencing clinically relevant toxicities, including hematological AEs and stomatitis. No carrier of the DPYD c.1679T>G minor allele was identified. Present results support the preemptive screening of mentioned DPYD and UGT1A1 variants to identify patients at risk of clinically relevant 5-fluoruracil- and irinotecan-related AEs, in order to improve treatments' safety through a "genotype-guided" approach.

PMID: 29487697 [PubMed]

Categories: Literature Watch

Genetic Parameter Estimates for Metabolizing Two Common Pharmaceuticals in Swine.

Thu, 2018-03-01 09:02

Genetic Parameter Estimates for Metabolizing Two Common Pharmaceuticals in Swine.

Front Genet. 2018;9:40

Authors: Howard JT, Ashwell MS, Baynes RE, Brooks JD, Yeatts JL, Maltecca C

Abstract
In livestock, the regulation of drugs used to treat livestock has received increased attention and it is currently unknown how much of the phenotypic variation in drug metabolism is due to the genetics of an animal. Therefore, the objective of the study was to determine the amount of phenotypic variation in fenbendazole and flunixin meglumine drug metabolism due to genetics. The population consisted of crossbred female and castrated male nursery pigs (n = 198) that were sired by boars represented by four breeds. The animals were spread across nine batches. Drugs were administered intravenously and blood collected a minimum of 10 times over a 48 h period. Genetic parameters for the parent drug and metabolite concentration within each drug were estimated based on pharmacokinetics (PK) parameters or concentrations across time utilizing a random regression model. The PK parameters were estimated using a non-compartmental analysis. The PK model included fixed effects of sex and breed of sire along with random sire and batch effects. The random regression model utilized Legendre polynomials and included a fixed population concentration curve, sex, and breed of sire effects along with a random sire deviation from the population curve and batch effect. The sire effect included the intercept for all models except for the fenbendazole metabolite (i.e., intercept and slope). The mean heritability across PK parameters for the fenbendazole and flunixin meglumine parent drug (metabolite) was 0.15 (0.18) and 0.31 (0.40), respectively. For the parent drug (metabolite), the mean heritability across time was 0.27 (0.60) and 0.14 (0.44) for fenbendazole and flunixin meglumine, respectively. The errors surrounding the heritability estimates for the random regression model were smaller compared to estimates obtained from PK parameters. Across both the PK and plasma drug concentration across model, a moderate heritability was estimated. The model that utilized the plasma drug concentration across time resulted in estimates with a smaller standard error compared to models that utilized PK parameters. The current study found a low to moderate proportion of the phenotypic variation in metabolizing fenbendazole and flunixin meglumine that was explained by genetics in the current study.

PMID: 29487615 [PubMed]

Categories: Literature Watch

[Dihydropyrimidine dehydrogenase (DPD) deficiency screening and securing of fluoropyrimidine-based chemotherapies: Update and recommendations of the French GPCO-Unicancer and RNPGx networks].

Thu, 2018-03-01 09:02

[Dihydropyrimidine dehydrogenase (DPD) deficiency screening and securing of fluoropyrimidine-based chemotherapies: Update and recommendations of the French GPCO-Unicancer and RNPGx networks].

Bull Cancer. 2018 Feb 24;:

Authors: Loriot MA, Ciccolini J, Thomas F, Barin-Le-Guellec C, Royer B, Milano G, Picard N, Becquemont L, Verstuyft C, Narjoz C, Schmitt A, Bobin-Dubigeon C, Harle A, Paci A, Poinsignon V, Quaranta S, Evrard A, Hennart B, Broly F, Fonrose X, Lafay-Chebassier C, Wozny AS, Masskouri F, Boyer JC, Etienne-Grimaldi MC

Abstract
Fluoropyrimidines (FU) are still the most prescribed anticancer drugs for the treatment of solid cancers. However, fluoropyrimidines cause severe toxicities in 10 to 40% of patients and toxic deaths in 0.2 to 0.8% of patients, resulting in a real public health problem. The main origin of FU-related toxicities is a deficiency of dihydropyrimidine dehydrogenase (DPD), the rate-limiting enzyme of 5-FU catabolism. DPD deficiency may be identified through pharmacogenetics testing including phenotyping (direct or indirect measurement of enzyme activity) or genotyping (detection of inactivating polymorphisms on the DPYD gene). Approximately 3 to 15% of patients exhibit a partial deficiency and 0.1 to 0.5% a complete DPD deficiency. Currently, there is no regulatory obligation for DPD deficiency screening in patients scheduled to receive a fluoropyrimidine-based chemotherapy. Based on the levels of evidence from the literature data and considering current French practices, the Group of Clinical Pharmacology in Oncology (GPCO)-UNICANCER and the French Network of Pharmacogenetics (RNPGx) recommend the following: (1) to screen DPD deficiency before initiating any chemotherapy containing 5-FU or capecitabine; (2) to perform DPD phenotyping by measuring plasma uracil (U) concentrations (possibly associated with dihydrouracil/U ratio), and DPYD genotyping (variants *2A, *13, p.D949V, HapB3); (3) to reduce the initial FU dose (first cycle) according to DPD status, if needed, and further, to consider increasing the dose at subsequent cycles according to treatment tolerance. In France, 17 public laboratories currently undertake routine screening of DPD deficiency.

PMID: 29486921 [PubMed - as supplied by publisher]

Categories: Literature Watch

The Alpha-2A Adrenergic Receptor Gene -1291C/G Single Nucleotide Polymorphism is Associated with the Efficacy of Methylphenidate in Treating Taiwanese Children and Adolescents with Attention-Deficit Hyperactivity Disorder.

Wed, 2018-02-28 08:32

The Alpha-2A Adrenergic Receptor Gene -1291C/G Single Nucleotide Polymorphism is Associated with the Efficacy of Methylphenidate in Treating Taiwanese Children and Adolescents with Attention-Deficit Hyperactivity Disorder.

Psychiatry Investig. 2018 Feb 28;:

Authors: Huang HC, Wu LS, Yu SC, Wu BJ, Lua AC, Lee SM, Liu CZ

Abstract
Objective: The therapeutic effect of methylphenidate (MPH) in treating attention-deficit/hyperactivity disorder (ADHD) has been related to the alpha-2A adrenergic receptor (ADRA2A) gene -1291C/G single nucleotide polymorphism (SNP). We investigated the effect of MPH in treating Taiwanese children and adolescent with ADHD and its relation to the ADRA2A gene -1291C/G SNP.
Methods: The subjects with DSM-IV ADHD diagnosis underwent a titration period to find out the dose of MPH for maintenance treatment. After 4 weeks maintenance treatment, the effect of MPH was evaluated by the Swanson, Nolan and Pelham version IV total scores. The subjects with more than 25% score reduction were referred to responders and those with ≥50% improvement were considered as better responders. The -1291C/G variant of the ADRA2A gene was identified by DNA sequencing and what relevance it has to the MPH response was examined by binary logistic regression analysis.
Results: Of the 59 subjects, 44 (74.6%) were responsive to MPH treatment and the responsiveness was not shown to be associated with the ADRA2A gene -1291C/G SNP. As the responsive subjects were categorized as moderate responders and better responders and subjected to statistical analysis, the GG homozygotes showed a greater chance to have a better response to MPH treatment than CC homozygotes (p=0.02), with an odds ratio of 32.14 (95% CI=1.64-627.80).
Conclusion: The ADRA2A gene -1291C/G SNP is associated with the efficacy of MPH for the treatment of ADHD in Taiwanese children and adolescents. The responsive subjects bearing homozygous -1291G allele are more likely to have a better response to MPH treatment.

PMID: 29486545 [PubMed - as supplied by publisher]

Categories: Literature Watch

Pharmacogenetics and target identification in diabetes.

Wed, 2018-02-28 08:32

Pharmacogenetics and target identification in diabetes.

Curr Opin Genet Dev. 2018 Feb 24;50:68-73

Authors: Pearson ER

Abstract
In diabetes, pharmacogenetics can be used both to identify patient subgroups who will have most benefit and/or least harm from a particularly treatment, and to gain insights into the molecular mechanisms of drug action and disease aetiology. There is increasing evidence that genetic variation alters response to diabetes treatments-both in terms of glycaemic response and side effects. This can be seen with dramatic impact on clinical care, in patients with genetic forms of diabetes such as Maturity Onset Diabetes of the Young caused by HNF1A mutations, and Neonatal diabetes due to activating mutations in ABCC8 or KCNJ11. Beyond monogenic diabetes, pharmacogenetic variants have yet to impact on clinical practice, yet the effect sizes (e.g. for metformin intolerance and OCT1 variants; or for metformin action and SLC2A2 variants) are potentially of clinical utility, especially if the genotype is already known at the point of prescribing. Over the next few years, increasing cohort sizes and linkage at scale to electronic medical records will provide considerable potential for stratification and novel target identification in diabetes.

PMID: 29486427 [PubMed - as supplied by publisher]

Categories: Literature Watch

Genome-wide association studies in Crohn's disease: Past, present and future.

Wed, 2018-02-28 08:32
Related Articles

Genome-wide association studies in Crohn's disease: Past, present and future.

Clin Transl Immunology. 2018;7(1):e1001

Authors: Verstockt B, Smith KG, Lee JC

Abstract
Over the course of the past decade, genome-wide association studies (GWAS) have revolutionised our understanding of complex disease genetics. One of the diseases that has benefitted most from this technology has been Crohn's disease (CD), with the identification of autophagy, the IL-17/IL-23 axis and innate lymphoid cells as key players in CD pathogenesis. Our increasing understanding of the genetic architecture of CD has also highlighted how a failure to suppress aberrant immune responses may contribute to disease development - a realisation that is now being incorporated into the design of new treatments. However, despite these successes, a significant proportion of disease heritability remains unexplained. Similarly, most of the causal variants at associated loci have not yet been identified, and even fewer have been functionally characterised. Because of the inarguable rise in the incidence of CD in regions of the world that previously had low disease rates, GWAS studies will soon have to shift from a largely Caucasian focus to include populations from other ethnic backgrounds. Future studies should also move beyond conventional studies of disease susceptibility into phenotypically driven 'within-cases' analyses in order to explore the role of genetics in other important aspects of disease biology. These studies are likely to include assessments of prognosis and/or response to treatments and may be critical if personalised medicine is ever to become a reality.

PMID: 29484179 [PubMed]

Categories: Literature Watch

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