Aucubin and its hydrolytic derivative attenuate activation of hepatic stellate cells via modulation of TGF-β stimulation.

Environ Toxicol Pharmacol. 2017 Mar;50:234-239

Authors: Lv PY, Feng H, Huang WH, Tian YY, Wang YQ, Qin YH, Li XH, Hu K, Zhou HH, Ouyang DS

Abstract
Eucommia ulmoides is an important traditional Chinese medicine and has been used as a tonic with a long history. Aucubin is an active component extracted from Eucommia ulmoides, which has liver-protection effects. However the mechanisms are still unclear. To investigate the inhibitory effects and the underlying mechanisms of aucubin on TGF-β1-induced activation of hepatic stellate cells and ECM deposition, Human hepatic stellate cells (LX-2 cells) were incubated with TGF-β1 to evaluate the anti-fibrotic effect of aucubin. Western blot was used to investigate the expression of α-SMA, Col I, Col III, MMP-2 and TIMP-1. ROS production was monitored using DCFH-DA probe, and NOX4 expression was detected by Real-time PCR. Results indicated that TGF-β1 stimulated the activation and ECM deposition of LX-2 cells. Compared with the control group, aucubin and aucubigenin both reduced the protein expression of α-SMA, Col I, Col III and MMP-2 in LX-2 cells. Aucubin and aucubigenin also suppressed the generation of ROS and down-regulated the NOX4 mRNA expression. Taken together, aucubin and aucubigenin both inhibit the activation and ECM deposition of LX-2 cells activated by TGF-β1. Aucubin and aucubigenin are potential therapeutic candidate drugs for liver fibrosis.

PMID: 28199906 [PubMed - indexed for MEDLINE]

No association between non-bullous skin reactions from lamotrigine and heterozygosity of UGT1A4 genetic variants *2(P24T) or *3(L48V) in Norwegian patients.

Seizure. 2017 Feb;45:169-171

Authors: Shirzadi M, Reimers A, Helde G, Sjursen W, Brodtkorb E

Abstract
PURPOSE: High initial serum concentrations increase the risk of cutaneous adverse reactions. Genetic variants of the main metabolizing isoenzyme, uridine diphosphate glucuronosyltransferase (UGT) 1A4 influence the elimination of lamotrigine (LTG). Our aim was to investigate the potential association between the two best studied variants, *2 (P24T) and *3 (L48V), and the occurrence non-bullous skin reactions from LTG.
METHOD: The study included 29 patients of Caucasian ethnicity with a history of non-bullous skin reactions from LTG. 184 subjects tolerant to LTG for at least three months were used as controls. UGT1A4 genotyping was performed in all patients and controls by sequencing of the first part of exon 1. Six controls were excluded due to rare genetic variants.
RESULTS: Two of 29 subjects (7%) with rash from LTG were heterozygous for UGT1A4 *2, compared to 23 of 178 (13%) tolerant controls (p=0.54). Four of 29 subjects (14%) with rash from LTG were heterozygous for UGT1A4 *3 compared to 25 of 178 (14%) tolerant controls (p=0.97).
CONCLUSION: It is unlikely that heterozygosity of the UGT1A4 genetic variants *2(P24T) or *3(L48V) influences the risk of non-bullous skin reactions in patients treated with LTG.

PMID: 28068583 [PubMed - indexed for MEDLINE]

Integrated Approaches to Drug Discovery for Oxidative Stress-Related Retinal Diseases.

Oxid Med Cell Longev. 2016;2016:2370252

Authors: Nishimura Y, Hara H

Abstract
Excessive oxidative stress induces dysregulation of functional networks in the retina, resulting in retinal diseases such as glaucoma, age-related macular degeneration, and diabetic retinopathy. Although various therapies have been developed to reduce oxidative stress in retinal diseases, most have failed to show efficacy in clinical trials. This may be due to oversimplification of target selection for such a complex network as oxidative stress. Recent advances in high-throughput technologies have facilitated the collection of multilevel omics data, which has driven growth in public databases and in the development of bioinformatics tools. Integration of the knowledge gained from omics databases can be used to generate disease-related biological networks and to identify potential therapeutic targets within the networks. Here, we provide an overview of integrative approaches in the drug discovery process and provide simple examples of how the approaches can be exploited to identify oxidative stress-related targets for retinal diseases.

PMID: 28053689 [PubMed - indexed for MEDLINE]

The challenges of pharmacokinetic variability of first-line anti-TB drugs.

Expert Rev Clin Pharmacol. 2017 Jan;10(1):47-58

Authors: Devaleenal Daniel B, Ramachandran G, Swaminathan S

Abstract
INTRODUCTION: Inter-individual variations in the pharmacokinetics (PK) of anti-TB drugs are known to occur, which could have important therapeutic implications in patient management. Areas covered: We compiled factors responsible for PK variability of anti-TB drugs reported from different settings that would give a better understanding about the challenges of PK variability of anti-TB medications. We searched PubMed data base and Google scholar from 1976 to the present using the key words 'Pharmacokinetics', 'pharmacokinetic variability', 'first-line anti-TB therapy', 'Rifampicin', 'Isoniazid', 'Ethambutol', 'Pyrazinamide', 'food', 'nutritional status', 'HIV', 'diabetes', 'genetic polymorphisms' and 'pharmacokinetic interactions'. We also included abstracts from scientific meetings and review articles. Expert commentary: A variety of host and genetic factors can cause inter-individual variations in the PK of anti-TB drugs. PK studies conducted in various settings have adopted different designs, PK sampling time points, drug estimation methodologies. Hence comparison and interpretation of these results should be done with caution More phamacogenomic studies in different patient populations are needed for further understanding.

PMID: 27724114 [PubMed - indexed for MEDLINE]

A Single Dose of the Anti-Resorptive Peptide Human Calcitonin Paradoxically Augments Particle- and Endotoxin-Mediated Pro-Inflammatory Cytokine Production In Vitro.

Horm Metab Res. 2016 Sep;48(9):607-12

Authors: Jablonski H, Wedemeyer C, Bachmann HS, Schlagkamp M, Bernstein A, Jäger M, Kauther MD

Abstract
The peptide hormone calcitonin (CT) is known to inhibit bone resorption and has previously been shown also to prevent particle-induced osteolysis, the leading cause of revision arthroplasty. In the present study, the influence of human CT on the initial inflammatory response to particulate wear debris or bacterial endotoxins, ultimately leading to osteoclast-mediated bone resorption, was analysed in human THP-1 macrophage-like cells. The cells were activated with either ultra-high molecular weight polyethylene (UHMWPE) particles or bacterial lipopolysaccharides (LPS) in order to simulate an osteolysis-associated inflammatory response. The cells were simultaneously treated with human CT (10(-9) M). Cytokine production of tumour necrosis factor (TNF)-α was quantified on both RNA and protein levels while interleukins (IL)-1β and IL-6 were measured as secreted protein only. Stimulation of the cells with either particles or LPS led to a dose- and time-dependent increase of TNF-α mRNA production and protein secretion of TNF-α, IL-1β, and IL-6. Application of CT mostly enhanced cytokine production as elicited by UHMWPE particles while a pronounced transient inhibitory effect on LPS-induced inflammation became evident at 24 h of incubation. Human CT displayed ambivalent effects on the wear- and LPS-induced production of pro-inflammatory cytokines. Thereby, the peptide primarily upregulated particle-induced inflammation while LPS-induced cytokine secretion was temporarily attenuated in a distinct manner. It needs to be evaluated whether the pro- or anti-inflammatory action of CT contributes to its known anti-resorptive effects. Thus, the therapeutic potential of the peptide in the treatment of either particle- or endotoxin-mediated bone resorption could be determined.

PMID: 27258971 [PubMed - indexed for MEDLINE]

Sirolimus and Everolimus Pathway: Reviewing Candidate Genes Influencing Their Intracellular Effects.

Int J Mol Sci. 2016 May 14;17(5):

Authors: Granata S, Dalla Gassa A, Carraro A, Brunelli M, Stallone G, Lupo A, Zaza G

Abstract
Sirolimus (SRL) and everolimus (EVR) are mammalian targets of rapamycin inhibitors (mTOR-I) largely employed in renal transplantation and oncology as immunosuppressive/antiproliferative agents. SRL was the first mTOR-I produced by the bacterium Streptomyces hygroscopicus and approved for several medical purposes. EVR, derived from SRL, contains a 2-hydroxy-ethyl chain in the 40th position that makes the drug more hydrophilic than SRL and increases oral bioavailability. Their main mechanism of action is the inhibition of the mTOR complex 1 and the regulation of factors involved in a several crucial cellular functions including: protein synthesis, regulation of angiogenesis, lipid biosynthesis, mitochondrial biogenesis and function, cell cycle, and autophagy. Most of the proteins/enzymes belonging to the aforementioned biological processes are encoded by numerous and tightly regulated genes. However, at the moment, the polygenic influence on SRL/EVR cellular effects is still not completely defined, and its comprehension represents a key challenge for researchers. Therefore, to obtain a complete picture of the cellular network connected to SRL/EVR, we decided to review major evidences available in the literature regarding the genetic influence on mTOR-I biology/pharmacology and to build, for the first time, a useful and specific "SRL/EVR genes-focused pathway", possibly employable as a starting point for future in-depth research projects.

PMID: 27187382 [PubMed - indexed for MEDLINE]

Quercetin induces caspase-dependent extrinsic apoptosis through inhibition of signal transducer and activator of transcription 3 signaling in HER2-overexpressing BT-474 breast cancer cells.

Oncol Rep. 2016 Jul;36(1):31-42

Authors: Seo HS, Ku JM, Choi HS, Choi YK, Woo JK, Kim M, Kim I, Na CH, Hur H, Jang BH, Shin YC, Ko SG

Abstract
Flavonoids are assumed to exert beneficial effects in different types of cancers at high concentrations. Yet, their molecular mechanisms of action remain unknown. The present study aimed to examine the effect of quercetin on proliferation and apoptosis in HER2-expressing breast cancer cells. The anti-proliferative effects of quercetin were examined by proliferation, MTT and clonogenic survival assays. The effect of quercetin on expression of apoptotic molecules was determined by western blotting. Luciferase reporter assay was performed to measure signal transducer and activator of transcription 3 (STAT3) transcriptional activity. ELISA assay was performed to measure intracellular MMP-9 levels. Immunocytochemistry was performed to evaluate the nuclear STAT3 level. The results revealed that quercetin inhibited the proliferation of BT-474 cells in a dose- and time-dependent manner. Quercetin also inhibited clonogenic survival (anchorage-dependent and -independent) of BT-474 cells in a dose-dependent manner. These growth inhibitions were accompanied with an increase in sub-G0/G1 apoptotic populations. Quercetin induced caspase-dependent extrinsic apoptosis upregulating the levels of cleaved caspase-8 and cleaved caspase-3, and inducing the cleavage of poly(ADP‑ribose) polymerase (PARP). In contrast, quercetin did not induce apoptosis via intrinsic mitochondrial apoptosis pathway since this compound did not decrease the mitochondrial membrane potential and did not affect the levels of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (BAX). Quercetin reduced the expression of phospho-JAK1 and phospho-STAT3 and decreased STAT3-dependent luciferase reporter gene activity in the BT-474 cells. Quercetin inhibited MMP-9 secretion and decreased the nuclear translocation of STAT3. Our study indicates that quercetin induces apoptosis at concentrations >20 µM through inhibition of STAT3 signaling and could serve as a useful compound to prevent or treat HER2-overexpressing breast cancer.

PMID: 27175602 [PubMed - indexed for MEDLINE]

Chemical shift assignments of the first and second RRMs of Nrd1, a fission yeast MAPK-target RNA binding protein.

Biomol NMR Assign. 2017 Mar 11;:

Authors: Kobayashi A, Kanaba T, Satoh R, Ito Y, Sugiura R, Mishima M

Abstract
Negative regulator differentiation 1 (Nrd1), a fission yeast RNA binding protein, modulates cytokinesis and sexual development and contributes to stress granule formation in response to environmental stresses. Nrd1 comprises four RRM domains and binds and stabilizes Cdc4 mRNA that encodes the myosin II light chain. Nrd1 binds the Cpc2 fission-yeast RACK1 homolog, and the interaction promotes Nrd1 localization to stress granules. Interestingly, Pmk1 mitogen-activated protein kinase phosphorylates Thr40 in the unstructured N-terminal region and Thr126 in the first RRM domain of Nrd1. Phosphorylation significantly reduces RNA-binding activity and likely modulates Nrd1 function. To reveal the relationship between the structure and function of Nrd1 and how phosphorylation affects structure, we used heteronuclear NMR techniques to investigate the three-dimensional structure of Nrd1. Here we report the (1)H, (13)C, and (15)N resonance assignments of RRM1-RRM2 (residues 108-284) comprising the first and second RRMs obtained using heteronuclear NMR techniques. Secondary structures derived from the chemical shifts are reported. These data should contribute to the understanding of the three-dimensional structure of the RRM1-RRM2 region of Nrd1 and the perturbation caused by phosphorylation.

PMID: 28284018 [PubMed - as supplied by publisher]

Pharmacokinetics and pharmacogenetics of the MEK1/2 inhibitor, selumetinib, in Asian and Western healthy subjects: a pooled analysis.

Eur J Clin Pharmacol. 2017 Mar 10;:

Authors: Dymond AW, Elks C, Martin P, Carlile DJ, Mariani G, Lovick S, Huang Y, Lorch U, Brown H, So K

Abstract
PURPOSE: Emerging data on selumetinib, a MEK1/2 inhibitor in clinical development, suggest a possible difference in pharmacokinetics (PK) between Japanese and Western patients. This pooled analysis sought to assess the effect of ethnicity on selumetinib exposure in healthy Western and Asian subjects, and to identify any association between genetic variants in the UGT1A1, CYP2C19 and ABCG2 genes and observed differences in selumetinib PK.
METHODS: A pooled analysis of data from ten Phase I studies, one in Asian subjects (encompassing Japanese, non-Japanese Asian and Indian Asian subjects) and nine in Western subjects, was conducted. Key findings were derived from the collective exposure data across doses of 25, 35, 50 and 75 mg selumetinib; primary variables were dose-normalized AUC and Cmax.
RESULTS: PK data from 308 subjects (10 studies) were available for the pooled analysis; genetic data from 87 subjects (3 studies) were available for the pharmacogenetic analysis. Dose-normalized AUC and Cmax were 35% (95% CI: 25-47%) and 39% (95% CI: 24-56%) higher in the pooled Asian group, respectively, compared with Western subjects. PK exposure parameters were similar between the Japanese, non-Japanese Asian and Indian groups. There was no evidence that the polymorphisms assessed in the genes UGT1A1, CYP2C19 and ABCG2 account for observed PK differences.
CONCLUSIONS: Selumetinib exposure was higher in healthy Asian subjects compared with Western subjects, and these data provide valuable insight for clinicians to consider when treating patients of Asian ethnicity with selumetinib.

PMID: 28283692 [PubMed - as supplied by publisher]

Pharmacogenetics in type 2 diabetes: precision medicine or discovery tool?

Diabetologia. 2017 Mar 10;:

Authors: Florez JC

Abstract
In recent years, technological and analytical advances have led to an explosion in the discovery of genetic loci associated with type 2 diabetes. However, their ability to improve prediction of disease outcomes beyond standard clinical risk factors has been limited. On the other hand, genetic effects on drug response may be stronger than those commonly seen for disease incidence. Pharmacogenetic findings may aid in identifying new drug targets, elucidate pathophysiology, unravel disease heterogeneity, help prioritise specific genes in regions of genetic association, and contribute to personalised or precision treatment. In diabetes, precedent for the successful application of pharmacogenetic concepts exists in its monogenic subtypes, such as MODY or neonatal diabetes. Whether similar insights will emerge for the much more common entity of type 2 diabetes remains to be seen. As genetic approaches advance, the progressive deployment of candidate gene, large-scale genotyping and genome-wide association studies has begun to produce suggestive results that may transform clinical practice. However, many barriers to the translation of diabetes pharmacogenetic discoveries to the clinic still remain. This perspective offers a contemporary overview of the field with a focus on sulfonylureas and metformin, identifies the major uses of pharmacogenetics, and highlights potential limitations and future directions.

PMID: 28283684 [PubMed - as supplied by publisher]

Comprehensive pharmacogenetic profiling of the epidermal growth factor receptor pathway for biomarkers of response to, and toxicity from, cetuximab.

J Med Genet. 2017 Mar 10;:

Authors: Madi A, Fisher D, Maughan TS, Colley JP, Meade AM, Tejpar S, Van den Bosch B, Maynard J, Humphreys V, Wasan H, Adams RA, Idziaszczyk S, Harris R, Kaplan RS, Cheadle JP

Abstract
BACKGROUND: Somatic mutations in the epidermal growth factor receptor (EGFR) intracellular signalling pathways predict non-response to cetuximab in the treatment of advanced colorectal cancer (aCRC). We hypothesised that common germline variants within these pathways may also play similar roles.
METHODS: We analysed 54 potentially functional, common, inherited EGFR pathway variants in 815 patients with aCRC treated with oxaliplatin-fluoropyrimidine chemotherapy plus cetuximab. Primary endpoints were response and skin rash (SR). We had >85% power to detect ORs=1.6 for variants with minor allele frequencies >20%.
RESULTS: We identified five potential biomarkers for response and four for SR, although none remained significant after correction for multiple testing. Our initial data supported a role for Ser313Pro in PIK3R2 in modulating response to cetuximab-in patients with KRAS wild-type CRCs, 36.4% with one allele encoding proline responded, as compared with 71.2% homozygous for allele encoding serine (OR 0.23, 95% CI 0.09 to 0.56, p=0.0014), and this association was predictive for cetuximab (pinteraction=0.017); however, independent replication failed to validate this association. No previously proposed predictive biomarkers were validated.
CONCLUSIONS: Our study highlights the need to validate potential pharmacogenetic biomarkers. We did not find strong evidence for common germline biomarkers of cetuximab response and toxicity.

PMID: 28283541 [PubMed - as supplied by publisher]

Ethical Issues Surrounding Personalized Medicine: A Literature Review.

Acta Med Iran. 2017 Mar;55(3):209-217

Authors: Salari P, Larijani B

Abstract
More than a decade ago, personalized medicine was presented in modern medicine. Personalized medicine means that the right drug should be prescribed for the right patient based on genetic data. No doubt is developing medical sciences, and its shift into personalized medicine complicates ethical challenges more than before. In this review, we categorized all probable ethical considerations of personalized medicine in research and development and service provision. Based on our review, extensive changes in healthcare system including ethical changes are needed to overcome the ethical obstacles including knowledge gap and informed consent, privacy and confidentiality and availability of healthcare services. Furthermore social benefit versus science development and individual benefit should be balanced. Therefore guidelines and regulations should be compiled to represent the ethical framework; also ethical decision making should be day-to-day and individualized.

PMID: 28282721 [PubMed - in process]

Precision Medicine Approach to Anaplastic Thyroid Cancer: Advances in Targeted Drug Therapy Based on Specific Signaling Pathways.

Acta Med Iran. 2017 Mar;55(3):200-208

Authors: Samimi H, Fallah P, Naderi Sohi A, Tavakoli R, Naderi M, Soleimani M, Larijani B, Haghpanah V

Abstract
Personalized medicine is a set of diagnostic, prognostic and therapeutic approaches in which medical interventions are carried out based on individual patient characteristics. As life expectancy increases in developed and developing countries, the incidence of diseases such as cancer goes up among people in the community. Cancer is a disease that the response to treatment varies from one person to another and also it is costly for individuals, families, and society. Among thyroid cancers, anaplastic thyroid carcinoma (ATC) is the most aggressive, lethal and unresponsive form of the disease. Unfortunately, current drugs are not targetable, and therefore they have restricted role in ATC treatment. Consequently, mortality of this cancer, despite advances in the field of diagnosis and treatment, is one of the most important challenges in medicine. Cellular, molecular and genetic evidences play an important role in finding more effective diagnostic and therapeutic approaches. Review of these evidences confirms the application of personalized medicine in cancer treatment including ATC. A growing body of evidence has elucidated that cellular and molecular mechanisms of cancer would pave the way for defining new biomarkers for targeted therapy, taking into account individual differences. It should be noted that this approach requires further progress in the fields of basic sciences, pharmacogenetics and drug design. An overview of the most important aspects in individualized anaplastic thyroid cancer treatment will be discussed in this review.

PMID: 28282720 [PubMed - in process]

Pharmacogenetics and Personalized Medicine in Pancreatic Cancer.

Acta Med Iran. 2017 Mar;55(3):194-199

Authors: Hosseini Bereshneh A, Morshedi F, Hematyar M, Kaki A, Garshasbi M

Abstract
 Pancreatic cancer (PC) is a progressive, fatal disease with a high degree of malignancy. More than 40000 peoplediefrom this cancer annually in the United States. As a multifactorial condition, PC has a complex nature, and there are several genes and signalingpathwaysimplicated in PC pathogenesis and progression. There are diffèrent mutations in master genesincludingtumorsuppressors and oncogenesthat lead to Pancreaticintraepithelialneoplasia (PanIN) whichis the mostcommon non-invasive precursorlesion of pancreatic cancer. These mutations influence directly or indirectly the cycle of Pharmacodynamics profile. Interactions between genetics and drug metabolism could be considered as one of the most important insights in the personalized medicine and targeted therapy based on the genetic profile of each affected person. In this literature, we will discuss pathogenesis and susceptibility to PC, pharmacogenetics and personalized medicine in pancreatic cancer and scrutinized the most important genes, variations and signaling pathways that influence individualized therapy of PC.

PMID: 28282719 [PubMed - in process]

Personalized Medicine: Pharmacogenomics and Drug Development.

Acta Med Iran. 2017 Mar;55(3):150-165

Authors: Mirsadeghi S, Larijani B

Abstract
Personalized medicine aims is to supply the proper drug to the proper patient within the right dose. Pharmacogenomics (PGx) is to recognize genetic variants that may influence drug efficacy and toxicity. All things considered, the fields cover a wide area, including basic drug discovery researches, the genetic origin of pharmacokinetics and pharmacodynamics, novel drug improvement, patient genetic assessment and clinical patient administration. At last, the objective of Pharmacogenomics is to anticipate a patient's genetic response to a particular drug as a way of presenting the best possible medical treatment. By predicting the drug response of an individual, it will be possible to increase the success of therapies and decrease the incidence of adverse side effect.

PMID: 28282716 [PubMed - in process]

Personalized Regenerative Medicine.

Acta Med Iran. 2017 Mar;55(3):144-149

Authors: Arjmand B, Goodarzi P, Mohamadi-Jahani F, Falahzadeh K, Larijani B

Abstract
Personalized medicine as a novel field of medicine refers to the prescription of specific therapeutics procedure for an individual. This approach has established based on pharmacogenetic and pharmacogenomic information and data. The terms precision and personalized medicines are sometimes applied interchangeably. However, there has been a shift from "personalized medicine" towards "precision medicine". Although personalized medicine emerged from pharmacogenetics, nowadays it covers many fields of healthcare. Accordingly, regenerative medicine and cellular therapy as the new fields of medicine use cell-based products in order to develop personalized treatments. Different sources of stem cells including mesenchymal stem cells, embryonic stem cells and induced pluripotent stem cells (iPSCs) have been considered in targeted therapies which could give many advantages. iPSCs as the novel and individual pluripotent stem cells have been introduced as the appropriate candidates for personalized cell therapies. Cellular therapies can provide a personalized approach. Because of person-to-person and population differences in the result of stem cell therapy, individualized cellular therapy must be adjusted according to the patient specific profile, in order to achieve best therapeutic results and outcomes. Several factors should be considered to achieve personalized stem cells therapy such as, recipient factors, donor factors, and the overall body environment in which the stem cells could be active and functional. In addition to these factors, the source of stem cells must be carefully chosen based on functional and physical criteria that lead to optimal outcomes.

PMID: 28282715 [PubMed - in process]

[Concepts applied to psychiatry pharmacogenomics].

Vertex. 2016 Sep;XXVII(129):383-392

Authors: Zorrilla Zubilete MA

Abstract
Pharmacogenetics studies the action of a drug in order to predict the response based on the genetic makeup of an individual. The objective of pharmacogenetic studies is to minimize the adverse effects and to ensure therapeutic benefit. Since psychotropic drugs have a high rate of variability in patient response, the aim of this paper is to update the pharmacogenetic concepts in psychopharmacology in a review that provides tools for rigorous analysis when prescribing a psychotropic drug. The purpose of clinical pharmacogenetic testing is to be able to distinguish between patients who are more or less responders to certain drugs, or on contrary, who are at increased risk for adverse events. The goal is to choose a drug therapy that can maximize the effectiveness in the treatment and minimize the risks of adverse reactions, thus improving the benefit / risk ratio.
IN CONCLUSION: technology is not a limiting factor nowadays; the challenge remains, however, to further develop research for clinical use, establishing an appropriate validation test, that is accurate, repeatable and reproducible, in order to safely detect gene sequences of clinical interest.

PMID: 28282076 [PubMed - in process]

Genetic risk variants as therapeutic targets for Crohn's disease.

Expert Opin Ther Targets. 2017 Apr;21(4):381-390

Authors: Gabbani T, Deiana S, Marocchi M, Annese V

Abstract
INTRODUCTION: The pathogenesis of Inflammatory bowel diseases (IBD) is multifactorial, with interactions between genetic and environmental factors. Despite the existence of genetic factors being largely demonstrated by epidemiological data and several genetic studies, only a few findings have been useful in term of disease prediction, disease progression and targeting therapy. Areas covered: This review summarizes the results of genome-wide association studies in Crohn's disease, the role of epigenetics and the recent discovery by genetic studies of new pathogenetic pathways. Furthermore, it focuses on the importance of applying genetic data to clinical practice, and more specifically how to better target therapy and predict potential drug-related toxicity. Expert opinion: Some genetic markers identified in Crohn`s disease have allowed investigators to hypothesize about, and in some cases, prove the usefulness of new specific therapeutic agents. However, the heterogeneity and complexity of this disease has so far limited the daily clinical use of genetic information. Finally, the study of the implications of genetics on therapy, either to predict efficacy or avoid toxicity, is considered still to be in its infancy.

PMID: 28281904 [PubMed - in process]

Transmembrane Domain Single-Nucleotide Polymorphisms Impair Expression and Transport Activity of ABC Transporter ABCG2.

Pharm Res. 2017 Mar 09;:

Authors: Sjöstedt N, van den Heuvel JJ, Koenderink JB, Kidron H

Abstract
PURPOSE: To study the function and expression of nine naturally occurring single-nucleotide polymorphisms (G406R, F431L, S441N, P480L, F489L, M515R, L525R, A528T and T542A) that are predicted to reside in the transmembrane regions of the ABC transporter ABCG2.
METHODS: The transport activity of the variants was tested in inside-out membrane vesicles from Sf9 insect and human derived HEK293 cells overexpressing ABCG2. Lucifer Yellow and estrone sulfate were used as probe substrates of activity. The expression levels and cellular localization of the variants was compared to the wild-type ABCG2 by western blotting and immunofluorescence microscopy.
RESULTS: All studied variants of ABCG2 displayed markedly decreased transport in both Sf9-ABCG2 and HEK293-ABCG2 vesicles. Impaired transport could be explained for some variants by altered expression levels and cellular localization. Moreover, the destructive effect on transport activity of variants G406R, P480L, M515R and T542A is, to our knowledge, reported for the first time.
CONCLUSIONS: These results indicate that the transmembrane region of ABCG2 is sensitive to amino acid substitution and that patients harboring these ABCG2 variant forms could suffer from unexpected pharmacokinetic events of ABCG2 substrate drugs or have an increased risk for diseases such as gout where ABCG2 is implicated.

PMID: 28281205 [PubMed - as supplied by publisher]

First Case of Foot Drop Associated with Capecitabine in a Patient with Thymidylate Synthase Polymorphism.

Cureus. 2017 Jan 24;9(1):e995

Authors: Wilks AB, Saif MW

Abstract
Capecitabine, an oral prodrug of 5-FU, has been approved by the FDA for use in patients with breast and colon cancers. In addition, capecitabine is commonly used in patients with other malignancies such as pancreatic, gastroesophageal, and hepatobiliary tract cancers. Though cerebellar toxicity is a rare but well-known side effect of intravenous 5-FU therapy, peripheral neuropathy with capecitabine has only been described in rare cases. In this case report, we describe a 79-year-old patient with locally advanced adenocarcinoma of the pancreas undergoing chemoradiation therapy with capecitabine who developed peripheral sensorimotor neuropathy. To the best of our knowledge, this is the first patient in the literature who was found to have two mutations (2R) of a 28 base-pair tandem repeat in the 5' promoter enhancer region (5'-TSER) on both alleles (2R/2R) of thymidylate synthetase (TYMS) gene, possibly responsible for the neurotoxicity.

PMID: 28280649 [PubMed - in process]