J. Pers. Med., Volume 8, Issue 4 (December 2018) – 15 articles

Fluoropyrimidine-based chemotherapy is extensively used for the treatment of solid cancers, including colorectal cancer. However, fluoropyrimidine-driven toxicities are a major problem in the management of the disease. The grade and type of the toxicities depend on demographic factors, but substantial inter-individual variation in fluoropyrimidine-related toxicity is partly explained by genetic factors. The aim of this study was to investigate the effect of dihydropyrimidine dehydrogenase (DPYD), thymidylate synthase (TYMS), and methylenetetrahydrofolate reductase (MTHFR) polymorphisms in colorectal cancer patients. Eighty-five patients who were administered fluoropyrimidine-based treatment were included in the study. The DPYD, TYMS and MTHFR polymorphisms were scanned by a next generation Sequenom MassARRAY. Fluoropyrimidine toxicities were observed in 92% of all patients. The following polymorphisms were detected: DPYD 85T>C (29.4% heterozygote mutants, 7.1% homozygote mutants), DPYD IVS 14+1G>A (1.2% heterozygote mutants), TYMS 1494del TTAAAG (38.4% heterozygote mutants, 24.7% homozygote mutants), MTHFR 677C>T (43.5% heterozygote mutants, 9.4% homozygote mutants) and MTHFR 1298A>C (8.2% heterozygote mutants, 2.4% homozygote mutants). A statistically significant association was demonstrated between MTHFR 677C>T and fluoropyrimidine-related toxicity (p value = 0.007). Furthermore, MTHFR 1298A>C was associated with hematopoietic toxicity (p value = 0.008). MTHFR polymorphisms may be considered as related factors of fluoropyrimidine toxicity and may be useful as predictive biomarkers for the determination of the colorectal cancer patients who can receive the greatest benefit from fluoropyrimidine-based treatments. Full article

Multiple genes and mechanisms of pathophysiology have been implicated in amyotrophic lateral sclerosis (ALS), suggesting it is a complex systemic disease. With this in mind, applying personalized medicine (PM) approaches to tailor treatment pipelines for ALS patients may be necessary. The modelling and analysis of molecular interaction networks could represent valuable resources in defining ALS-associated pathways and discovering novel therapeutic targets. Here we review existing omics datasets and analytical approaches, in order to consider how molecular interaction networks could improve our understanding of the molecular pathophysiology of this fatal neuromuscular disorder. Full article

The 9th traditional biannual conference on Systems Medicine, Personalised Health & Therapy—“The Odyssey from Hope to Practice”, inspired by the Greek mythology, was a call to search for practical solutions in cardio-metabolic diseases and cancer, to resolve and overcome the obstacles in modern medicine by creating more interactions among disciplines, as well as between academic and industrial research, directed towards an effective ‘roadmap’ for personalised health and therapy. The 9th Santorini Conference, under the Presidency of Sofia Siest, the director of the INSERM U1122; IGE-PCV (www.u1122.inserm.fr), University of Lorraine, France, offered a rich and innovative scientific program. It gathered 34 worldwide distinguished speakers, who shared their passion for personalised medicine with 160 attendees in nine specific sessions on the following topics: First day: The Odyssey from hope to practice: Personalised medicine—landmarks and challenges Second day: Diseases to therapeutics—genotype to phenotype an “-OMICS” approach: focus on personalised therapy and precision medicine Third day: Gene-environment interactions and pharmacovigilance: a pharmacogenetics approach for deciphering disease “bench to clinic to reality” Fourth day: Pharmacogenomics to drug discovery: a big data approach and focus on clinical data and clinical practice. In this article we present the topics shared among the participants of the conference and we highlight the key messages. Full article

The organic cation transporter 1 (OCT1, SLC22A1) is strongly expressed in the human liver and facilitates the hepatic uptake of drugs such as morphine, metformin, tropisetron, sumatriptan and fenoterol and of endogenous substances such as thiamine. OCT1 expression is inter-individually highly variable. Here, we analyzed SNPs in the OCT1 promoter concerning their potential contribution to the variability in OCT1 expression. Using electrophoretic mobility shift and luciferase reporter gene assays in HepG2, Hep3B, and Huh7 cell lines, we identified the SNPs −1795G>A (rs6935207) and −201C>G (rs58812592) as having effects on transcription factor binding and/or promoter activity. The A-allele of the −1795G>A SNP showed allele-specific binding of the transcription factor NF-Y leading to 2.5-fold increased enhancer activity of the artificial SV40 promoter. However, the −1795G>A SNP showed no significant effects on the native OCT1 promoter activity. Furthermore, the −1795G>A SNP was not associated with the pharmacokinetics of metformin, fenoterol, sumatriptan and proguanil in healthy individuals or tropisetron efficacy in patients undergoing chemotherapy. Allele-dependent differences in USF1/2 binding and nearly total loss in OCT1 promoter activity were detected for the G-allele of −201C>G, but the SNP is apparently very rare. In conclusion, common OCT1 promoter SNPs have only minor effects on OCT1 expression. Full article

Duchenne muscular dystrophy (DMD), a fatal X-linked recessive disorder, is caused mostly by frame-disrupting, out-of-frame deletions in the dystrophin (DMD) gene. Antisense oligonucleotide-mediated exon skipping is a promising therapy for DMD. Exon skipping aims to convert out-of-frame mRNA to in-frame mRNA and induce the production of internally-deleted dystrophin as seen in the less severe Becker muscular dystrophy. Currently, multiple exon skipping has gained special interest as a new therapeutic modality for this approach. Previous retrospective database studies represented a potential therapeutic application of multiple exon skipping. Since then, public DMD databases have become more useful with an increase in patient registration and advances in molecular diagnosis. Here, we provide an update on DMD genotype-phenotype associations using a global DMD database and further provide the rationale for multiple exon skipping development, particularly for exons 45–55 skipping and an emerging therapeutic concept, exons 3–9 skipping. Importantly, this review highlights the potential of multiple exon skipping for enabling the production of functionally-corrected dystrophin and for treating symptomatic patients not only with out-of-frame deletions but also those with in-frame deletions. We will also discuss prospects and challenges in multiple exon skipping therapy, referring to recent progress in antisense chemistry and design, as well as disease models. Full article

ATP-binding cassette (ABC) transporters are involved in a large number of processes and contribute to various human genetic diseases. Among other functions, ABC proteins are involved in the transport of multiple drugs through cells. Most of the genes coding for these transporters are highly polymorphic and DNA variants in these genes can affect the normal functioning of these proteins, affecting the way drugs are transported, increasing or decreasing drug levels. These changes in the intracellular and extracellular drug levels may be associated with altered drug effectiveness or severe drug-induced adverse events. This review presents a state-of-art of the most pharmacogenetics clinically relevant ABC transporters closed to the clinical implementation. Full article

Personalized tools relevant to an individual patient’s unique characteristics may be an important component of personalized health care. We randomized 97 patients hospitalized with acute decompensated heart failure to receive a printout of an ultrasound image of their inferior vena cava (IVC) with an explanation of how the image is related to their fluid status (n = 50) or to receive no image and only generic heart failure information (n = 47). Adherence to medications, low-sodium diet, and daily weight measurement at baseline and 30 days after discharge were assessed using the Medical Outcomes Study Specific Adherence Scale, modified to a three-item version for heart failure (HF), (MOSSAS-3HF, maximum score = 15, indicating adherence all of the time). The baseline MOSSAS-3HF scores (mean ± standard deviation (SD)) were similar for intervention and control groups (7.4 ± 3.4 vs. 6.4 ± 3.7, p = 0.91). The MOSSAS-3HF scores improved for both groups but were not different at 30 days (11.8 ± 2.8 vs. 11.7 ± 3.0, p = 0.90). Survival without readmission or emergency department (ED) visit at 30 days was similar (82.6% vs. 84.1%, p = 0.85). A personalized HF tool did not affect rates of self-reported HF treatment adherence or survival without readmission or ED visit. Full article

Duchenne muscular dystrophy (DMD) is a fatal X-linked recessive neuromuscular disease prevalent in 1 in 3500 to 5000 males worldwide. As a result of mutations that interrupt the reading frame of the dystrophin gene (DMD), DMD is characterized by a loss of dystrophin protein that leads to decreased muscle membrane integrity, which increases susceptibility to degeneration. CRISPR/Cas9 technology has garnered interest as an avenue for DMD therapy due to its potential for permanent exon skipping, which can restore the disrupted DMD reading frame in DMD and lead to dystrophin restoration. An RNA-guided DNA endonuclease system, CRISPR/Cas9 allows for the targeted editing of specific sequences in the genome. The efficacy and safety of CRISPR/Cas9 as a therapy for DMD has been evaluated by numerous studies in vitro and in vivo, with varying rates of success. Despite the potential of CRISPR/Cas9-mediated gene editing for the long-term treatment of DMD, its translation into the clinic is currently challenged by issues such as off-targeting, immune response activation, and sub-optimal in vivo delivery. Its nature as being mostly a personalized form of therapy also limits applicability to DMD patients, who exhibit a wide spectrum of mutations. This review summarizes the various CRISPR/Cas9 strategies that have been tested in vitro and in vivo for the treatment of DMD. Perspectives on the approach will be provided, and the challenges faced by CRISPR/Cas9 in its road to the clinic will be briefly discussed. Full article

This study aims to investigate the effects of the three potassium channel genes KCNA1, KCNA2, and KCNV2 on increased susceptibility to epilepsy as well as on responsiveness to antiepileptic drugs (AEDs). The pharmacogenetic and case-control cohort (n = 595) consisted of 296 epileptic patients and 299 healthy individuals. Epileptic patients were recruited from the Pediatric Neurology clinic at the Queen Rania Al Abdullah Hospital (QRAH) in Amman, Jordan. A custom platform array search for genetic association in Jordanian-Arab epileptic patients was undertaken. The MassARRAY system (iPLEX GOLD) was used to genotype seven single nucleotide polymorphisms (SNPs) within three candidate genes (KCNA1, KCNA2, and KCNV2). Only one SNP in KCNA2, rs3887820, showed significant association with increased risk of susceptibility to generalized myoclonic seizure (p-value < 0.001). Notably, the rs112561866 polymorphism of the KCNA1 gene was non-polymorphic, but no significant association was found between the KCNA1 (rs2227910, rs112561866, and rs7974459) and KCNV2 (rs7029012, rs10967705, and rs10967728) polymorphisms and disease susceptibility or drug responsiveness among Jordanian patients. This study suggests that a significant association exists between the KCNA2 SNP rs3887820 and increased susceptibility to generalized myoclonic seizure. However, the present findings indicate that the KCNA1 and KCNV2 SNPs do not influence disease susceptibility and drug responsiveness in epileptic patients. Pharmacogenetic and case-control studies involving a multicenter and multiethnic approach are needed to confirm our results. To improve the efficacy and safety of epilepsy treatment, further studies are required to identify other genetic factors that contribute to susceptibility and treatment outcome. Full article

The pricing of targeted medicines continues to be a major area of contention in healthcare economics. This issue is further complicated by redefining the role of molecular testing in precision medicine. Currently, whilst pricing of clinical laboratory diagnostics is cost-based, drug pricing is value-based. The pricing for molecular testing is under pressure to change the traditional business model, for it has a critical subsidiary role in determining the final value of targeted medicines. The market size for drugs is reduced by molecular testing when patients with the same disease are stratified based on their genetics, it is critical to determine the value of this new enhanced drug specificity to realize its full pricing potential. However, these value-based pricing strategies require a careful understanding of changing market conditions, especially, in the context of stratified patient segments made possible by precision medicine. In this article, we discuss the various factors impacting pricing decisions, and consider evolving economic trends in precision medicine. Full article

Familial Hypercholesterolemia (FH) is an inherited disorder associated with increased cardiovascular risk that requires patients to make multiple impactful decisions regarding the management of their condition. Patient decision aids (PDAs) can facilitate shared decision-making (SDM) and enable patients to make choices that are concordant with their goals and values. To inform the development of a PDA for patients with FH, we employed a qualitative inductive approach and focus group discussions with patients, physicians, and genetic counselors. We explored and analyzed the perceptions and understanding of these stakeholders related to a PDA for FH and identified important concepts to include in the PDA. Categories emerging from focus group discussions included: (a) perceptions of a PDA related to FH; (b) discussion about the content of a PDA related to FH; and (c) SDM. In general, stakeholders were in favor of developing tools which can inform and individualize discussion about genetic testing and treatment options for FH. Physicians valued a tool that facilitates knowledge transfer to FH patients. Patients desired a tool to help them understand the genetic aspects of and treatment options related to FH. Genetic counselors emphasized the inclusion of visual aids to support discussion with patients. Potential barriers to and facilitators of PDA implementation were identified. The input of various stakeholders will inform the development of a prototype tool that will be iteratively tested before implementation in the clinical setting. Full article

Atherosclerosis affects millions of people worldwide. However, the wide variety of limitations in the current therapeutic options leaves much to be desired in future lipid-lowering therapies. For example, although statins, which are the first-line treatment for coronary heart disease (CHD), reduce the risk of cardiovascular events in a large percentage of patients, they lead to optimal levels of low density lipoprotein-cholesterol (LDL-C) in only about one-third of patients. A new promising research direction against atherosclerosis aims to improve lipoprotein metabolism. Novel therapeutic approaches are being developed to increase the levels of functional high density lipoprotein (HDL) particles. This review aims to highlight the atheroprotective potential of the in vitro synthesized reconstituted HDL particles containing apolipoprotein E (apoE) as their sole apolipoprotein component (rHDL-apoE). For this purpose, we provide: (1) a summary of the atheroprotective properties of native plasma HDL and its apolipoprotein components, apolipoprotein A-I (apoA-I) and apoE; (2) an overview of the anti-atherogenic functions of rHDL-apoA-I and apoA-I-containing HDL, i.e., natural HDL isolated from transgenic Apoa1^−/− × Apoe^−/− mice overexpressing human apoA-I (HDL-apoA-I); and (3) the latest developments and therapeutic potential of HDL-apoE and rHDL-apoE. Novel rHDL formulations containing apoE could possibly present enhanced biological functions, leading to improved therapeutic efficacy against atherosclerosis. Full article

The field of interventional cardiology has evolved significantly since the first percutaneous transluminal coronary angioplasty was performed 40 years ago. This evolution began with a balloon catheter mounted on a fixed wire and has progressed into bare-metal stents (BMS), first-generation drug-eluting stents (DES), second- and third-generation biodegradable polymer-based DES, and culminates with the advent of bioabsorbable stents, which are currently under development. Each step in technological advancement has improved outcomes, while new persisting challenges arise, caused by the stent scaffolds, the polymers employed, and the non-selective cytostatic and cytotoxic drugs eluted from the stents. Despite the promising technological advances made in stent technology, managing the balance between reductions in target lesion revascularization, stent thrombosis, and bleeding remain highly complex issues. This review summarizes the evolution of percutaneous coronary intervention with a focus on vascular dysfunction triggered by the non-selective drugs eluted from various stents. It also provides an overview of the mechanism of action of the drugs currently used in DES. We also discuss the efforts made in developing novel cell-selective drugs capable of inhibiting vascular smooth muscle cell (VSMC) proliferation, migration, and infiltration of inflammatory cells while allowing for complete reendothelialization. Lastly, in the era of precision medicine, considerations of patients’ genetic variance associated with myocardial infarction and in-stent restenosis are discussed. The combination of personalized medicine and improved stent platform with cell-selective drugs has the potential to solve the remaining challenges and improve the care of coronary artery disease patients. Full article

Recent advances in genomic medicine have led to the availability of genomic tests that have the potential to improve population health, yet the process for obtaining these tests and getting them reimbursed by insurers has not been described. The objective of this study was to describe the process of ordering pharmacogenomic tests by interviewing providers, patients, and laboratories about cancer-related pharmacogenomic tests. We interviewed patients who were prescribed, providers who prescribed medications that should be guided by pharmacogenomic testing, and individuals from diagnostic laboratories. A total of 10 providers, 16 patients, and eight diagnostic laboratories described logistical and insurance issues relating to ordering and receiving pharmacogenomic tests and medications. We found that the process of ordering pharmacogenomic tests is time-consuming, expensive, and complex. Ordering pharmacogenomic tests is quite different across institutions. Even in the same institution, multiple providers can order the test. Once the provider places the order for the pharmacogenomic test, the laboratory receives the request and usually begins testing without knowing how the test will be paid for. Next, the laboratory completes the pharmacogenomic testing and the results of the tests are reported to providers, patients, or placed directly in the medical record. In conclusion, processes related to ordering and obtaining insurance coverage for pharmacogenomic tests varies greatly across institutions and is time-consuming. Full article

In this endeavour, inspired by the Odyssey, we aim to embark with the reader on a journey on a ship from Troy to Ithaca, coursing through the history of the momentous events and achievements that paved the way for personalised medicine. We will set sail amidst important genetic discoveries, beginning with the discovery of the first human genome, and voyage through the projects that contributed to the progress of pharmacogenomic studies. Concurrently, we will propose methods to overcome the obstacles that are slowing the potential full implementation of accumulated knowledge into everyday practice. This journey aims to reflect on the frontiers of current genetic knowledge and the practical use of this knowledge in preventive, diagnostic and pharmacogenomic approaches to directly impact the socio-economic aspects of public health. Full article