Cardiovascular pharmacogenomics: current status and future directions

Cancer treatment comes to age: from one-size-fits-all to next-generation sequencing (NGS) technologies

Cancer is one of the leading causes of death worldwide and one of the greatest challenges in extending life expectancy. The paradigm of one-size-fits-all medicine has already given way to the stratification of patients by disease subtypes, clinical characteristics, and biomarkers (stratified medicine). The introduction of next-generation sequencing (NGS) in clinical oncology has made it possible to tailor cancer patient therapy to their molecular profiles. NGS is expected to lead the transition to precision medicine (PM), where the right therapeutic approach is chosen for each patient based on their characteristics and mutations. Here, we highlight how the NGS technology facilitates cancer treatment. In this regard, first, precision medicine and NGS technology are reviewed, and then, the NGS revolution in precision medicine is described. In the sequel, the role of NGS in oncology and the existing limitations are discussed. The available databases and bioinformatics tools and online servers used in NGS data analysis are also reviewed. The review ends with concluding remarks.

Associations between Selected ADRB1 and CYP2D6 Gene Polymorphisms in Children with Ventricular and Supraventricular Arrhythmias

Background and Objectives: Tachycardia is a common cardiovascular disease. Drugs blocking β1-adrenergic receptors (ADRB1) are used in the therapy of arrhythmogenic heart diseases. Disease-related polymorphisms can be observed within the ADRB1 gene. The two most important are Ser49Gly and Arg389Gly, and they influence the treatment efficacy. The family of the cytochrome P450 system consists of the isoenzyme CYP2D6 (Debrisoquine 4-hydroxylase), which is involved in phase I metabolism of almost 25% of clinically important drugs, including antiarrhythmic drugs. A study was conducted to detect the ADRB1 and CYP2D6 gene polymorphisms. Materials and Methods: The material for the test was whole blood from 30 patients with ventricular and supraventricular tachycardia and 20 controls. The samples were obtained from the Department of Pediatric Cardiology. The first to be made was the extraction of DNA using a GeneMATRIX Quick Blood DNA Purification Kit from EURx. The selected ADRB1 and CYP2D6 gene polymorphisms were detected by high-resolution melting polymerase chain reaction (HRM-PCR) analysis. Results: Based on the analysis of melt profile data for each PCR product, the identification of polymorphisms was carried out. Heterozygotes and homozygotes were found in the examined alleles. Conclusions: The frequency of the Arg389Gly polymorphism differs statistically significantly between the control group and patients with supraventricular and ventricular arrhythmias, as well as between these two groups of patients. Moreover, the Arg389Gly polymorphism was statistically more prevalent in the group of girls with SVT arrhythmia compared to girls with VT. A few carriers of homozygous and heterozygous systems of the S49G polymorphism were detected among patients with arrhythmias, as well as control group. The percentage of individuals carrying the CYP2D6 4 allele as either homozygous or heterozygous was observed in the study and control groups. The high prevalence of the CYP2D6*4 allele carriers in both groups prompts the optimization of beta-1 blocker therapy.

Estimating the efficacy of pharmacogenomics over a lifetime

It is well known that common variants in specific genes influence drug metabolism and response, but it is currently unknown what fraction of patients are given prescriptions over a lifetime that could be contraindicated by their pharmacogenomic profiles. To determine the clinical utility of pharmacogenomics over a lifetime in a general patient population, we sequenced the genomes of 300 deceased Marshfield Clinic patients linked to lifelong medical records. Genetic variants in 33 pharmacogenes were evaluated for their lifetime impact on drug prescribing using extensive electronic health records. Results show that 93% of the 300 deceased patients carried clinically relevant variants. Nearly 80% were prescribed approximately three medications on average that may have been impacted by these variants. Longitudinal data suggested that the optimal age for pharmacogenomic testing was prior to age 50, but the optimal age is greatly influenced by the stability of the population in the healthcare system. This study emphasizes the broad clinical impact of pharmacogenomic testing over a lifetime and demonstrates the potential application of genomic medicine in a general patient population for the advancement of precision medicine.

Computational Approaches Integrated in a Digital Ecosystem Platform for a Rare Disease

Alkaptonuria (AKU) is an ultra-rare autosomal recessive disease caused by a mutation in the homogentisate 1,2-dioxygenase gene. One of the main obstacles in studying AKU and other ultra-rare diseases, is the lack of a standardized methodology to assess disease severity or response to treatment. Based on that, a multi-purpose digital platform, called ApreciseKUre, was implemented to facilitate data collection, integration and analysis for patients affected by AKU. It includes genetic, biochemical, histopathological, clinical, therapeutic resources and Quality of Life (QoL) scores that can be shared among registered researchers and clinicians to create a Precision Medicine Ecosystem. The combination of machine learning applications to analyse and re-interpret data available in the ApreciseKUre clearly indicated the potential direct benefits to achieve patients' stratification and the consequent tailoring of care and treatments to a specific subgroup of patients. In order to generate a comprehensive patient profile, computational modeling and database construction support the identification of potential new biomarkers, paving the way for more personalized therapy to maximize the benefit-risk ratio. In this work, different Machine Learning implemented approaches were described.

Biochip-based approach for comprehensive pharmacogenetic testing

OBJECTIVES

Individual sensitivity to many widely used drugs is significantly associated with genetic factors. The purpose of our work was to develop an instrument for simultaneous determination of the most clinically relevant pharmacogenetic markers to allow personalized treatment, mainly in patients with cardiovascular diseases.

METHODS

Multiplex one-step polymerase chain reaction (PCR) followed by hybridization on a low-density biochip was applied to interrogate 15 polymorphisms in the following eight genes: VKORC1 -1639 G>A, CYP4F2 1297 G>A, GGCX 2374 C>G, CYP2C9 *2,*3 (430 C>T, 1075 A>C), CYP2D6 *3,*4, *6, *9, *41 (2549delA, 1846 G>A, 1707delT, 2615_2617delAAG, 2988 G>A), CYP2C19 *2,*3,*17 (681 G>A, 636 G>A, -806 C>T), ABCB1 (3435 C>T), SLCO1B1 *5.

RESULTS

Two hundred nineteen patients with cardiovascular diseases (CVD) and 48 female patients with estrogen receptor (ER)-positive breast cancer (BC) were genotyped. Of the 219 CVD patients, 203 (92.7%) carried one or more actionable at-risk genotypes based on VKORC1/CYP2C9, CYP2C9, CYP2C19, SLCO1B1, and CYP2D6 genotypes. Among them, 67 patients (30.6%) carried one, 58 patients (26.5%) carried two, 51 patients (23.3%) carried three, 26 patients (11.9%) carried four, and one patient (0.4%) carried five risk actionable genotypes. In the ER-positive BC group 12 patients (25%) were CYP2D6 intermediate or poor metabolizers.

CONCLUSIONS

The developed biochip is applicable for rapid and robust genotyping of patients who were taking a wide spectrum of medications to optimize drugs and dosage and avoid adverse drug reactions in cardiology, oncology, psychiatry, rheumatology and gastroenterology.

The impact of real-world cardiovascular-related pharmacogenetic testing in an insured population

BACKGROUND

Pharmacogenomics is intended to help clinicians provide the right drug to the right patient at an appropriate dose. However, limited evidence of clinical utility has slowed uptake of pharmacogenomic testing (PGT).

OBJECTIVE

To evaluate the impact of real-world cardiovascular (CV)-related PGT on clinical outcomes, healthcare resource utilisation (HCRU) and cost in a large, heterogeneous population.

METHODS

Individuals with Medicare Advantage Prescription Drug, Medicaid, or commercial coverage between 1/1/2011 and 9/30/2015 and ≥1 atherosclerotic CV-related diagnosis were identified. Those with ≥1 claim for CV-related PGT were included in the test group (index date = 1st PGT claim) and matched 1:2 to controls without PGT. Individuals aged <22 or ≥90 years old on the index date, with <12 months continuous enrollment before and after the index date, or without an ASCVD-related diagnosis in the 12-month pre-index period were excluded. The primary outcome was occurrence of a major CV event during the 12-month post-index period.

RESULTS

After adjustment, the PGT group was significantly more likely to experience ischaemic stroke, pulmonary embolism, deep vein thrombosis or a composite event compared with controls. Adjusting for baseline characteristics, HCRU was significantly higher for the test group across all measured outcomes except all-cause and ASCVD-related inpatient admissions. Median all-cause and ASCVD-related healthcare costs were significantly higher for the test group.

CONCLUSIONS

Real world PGT in a large population did not improve outcomes. Tailoring medication therapy to each patient holds great promise for providing quality care but a deeper understanding of how widespread utilisation of PGT might impact objective health outcomes is needed.

Biomarkers in cardiovascular disease: Statistical assessment and section on key novel heart failure biomarkers

Cardiovascular disease (CVD) is a leading cause of death worldwide and continues to increase in prevalence compared to previous decades, in part because of the aging of the world population. Atherosclerotic CVD starts at a very young age and progresses over time allowing sufficient time for screening and early detection of the condition. Advances in biomarker research and developments related to CVD over the past 30 years have led to more sensitive screening methods, a greater emphasis on its early detection and diagnosis, and improved treatments resulting in more favorable clinical outcomes in the community. However, the use of biomarkers for different purposes in CVD remains an important area of research that has been explored by scientists over the years and many new developments are still underway. Therefore, a detailed description of all CVD biomarkers that are currently been used or investigated for future use in the field of cardiovascular medicine is out of scope for any review article. In the present review, we do not intend to replicate the information from previous exhaustive review on biomarkers, but highlight key statistical and clinical issues with an emphasis on methods to evaluate the incremental yield of biomarkers, including their clinical utility, a prerequisite before any putative novel biomarker is utilized in clinical practice. In addition, we will summarize information regarding recent novel heart failure biomarkers in current practice, which are undergoing scrutiny before they can be available for clinical use, and their impact on clinical outcomes.

Are Genetic Tests for Atherosclerosis Ready for Routine Clinical Use?

In this review, we lay out 3 areas currently being evaluated for incorporation of genetic information into clinical practice related to atherosclerosis. The first, familial hypercholesterolemia, is the clearest case for utility of genetic testing in diagnosis and potentially guiding treatment. Already in use for confirmatory testing of familial hypercholesterolemia and for cascade screening of relatives, genetic testing is likely to expand to help establish diagnoses and facilitate research related to most effective therapies, including new agents, such as PCSK9 inhibitors. The second area, adding genetic information to cardiovascular risk prediction for primary prevention, is not currently recommended. Although identification of additional variants may add substantially to prediction in the future, combining known variants has not yet demonstrated sufficient improvement in prediction for incorporation into commonly used risk scores. The third area, pharmacogenetics, has utility for some therapies today. Future utility for pharmacogenetics will wax or wane depending on the nature of available drugs and therapeutic strategies.

Identification of Small Molecule Inhibitors of Human As(III) S-Adenosylmethionine Methyltransferase (AS3MT)

Arsenic is the most ubiquitous environmental toxin and carcinogen. Long-term exposure to arsenic is associated with human diseases including cancer, cardiovascular disease, and diabetes. Human As(III) S-adenosylmethionine (SAM) methyltransferases (hAS3MT) methylates As(III) to trivalent mono- and dimethyl species that are more toxic and potentially more carcinogenic than inorganic arsenic. Modulators of hAS3MT activity may be useful for the prevention or treatment of arsenic-related diseases. Using a newly developed high-throughput assay for hAS3MT activity, we identified 10 novel noncompetitive small molecule inhibitors. In silico docking analysis with the crystal structure of an AS3MT orthologue suggests that the inhibitors bind in a cleft between domains that is distant from either the As(III) or SAM binding sites. This suggests the presence of a possible allosteric and regulatory site in the enzyme. These inhibitors may be useful tools for future research in arsenic metabolism and are the starting-point for the development of drugs against hAS3MT.

Improving medical students' knowledge of genetic disease: a review of current and emerging pedagogical practices

Genetics is an essential subject to be mastered by health professional students of all types. However, technological advances in genomics and recent pedagogical research have changed the way in which many medical training programs teach genetics to their students. These advances favor a more experience-based education focused primarily on developing student's critical thinking skills. In this review, we examine the current state of genetics education at both the preclinical and clinical levels and the ways in which medical and pedagogical research have guided reforms to current and emerging teaching practices in genetics. We discover exciting trends taking place in which genetics is integrated with other scientific disciplines both horizontally and vertically across medical curricula to emphasize training in scientific critical thinking skills among students via the evaluation of clinical evidence and consultation of online databases. These trends will produce future health professionals with the skills and confidence necessary to embrace the new tools of medical practice that have emerged from scientific advances in genetics, genomics, and bioinformatics.