Nathalie Khoueiry Zgheib

Introduction: Tobacco smoking remains a leading cause of many life-threatening diseases, particularly lung cancer. Waterpipe smoking has rapidly gained popularity worldwide, while research on this tobacco form remains limited. Tobacco smoking has been linked to the shortening of telomeres and activation of telomerase, important regulators of genomic stability and cancer progression. However, the direct impact of whole-smoke exposure on telomere dynamics and its relationship with cancer progression remains minimally explored, and this requires suitable experimental systems. Methods: This study aims to demonstrate an experimental procedure to enable prolonged exposure of lung cancer cells (A549) to sub-toxic concentrations of cigarette and waterpipe smoke extracts, and to investigate in those cells the effects on telomere length, telomerase activity, and cancer progression. We also checked telomere length, epithelial-to-mesenchymal transition (EMT) markers, and migration in two other colon (HCT116) and breast cancer (MCF7) cell lines. Results: After 12 weeks of exposure, there was a significant decrease in relative telomere length in heterogeneous/parents of A549 cells with waterpipe exposure, and a significant increase in telomerase activity with cigarette exposure. Chronic exposure to both smoke extracts also led to a significant upregulation in the expression of the SNAI2 mesenchymal marker in both heterogeneous populations and single-cell-derived colonies. Additionally, chronic exposure to cigarette smoke extract significantly enhanced migration in single-cell-derived colonies. Comparable results were seen in the colonies of colon and breast cancer cell lines. Discussion: Our findings revealed that chronic smoke exposure disrupts telomere dynamics particularly in lung cancer cells and triggers transcriptional EMT changes that might contribute to cancer progression in lung, breast, and colon cancer cells, offering new insights into a potential link between tobacco smoke, telomere dysfunction, and cancer progression.

This study aims to investigate the association between candidate host genetic polymorphisms and COVID-19 susceptibility, severity, hospitalization, hypoxia, and their combined effect, measured by the polygenic risk score (PRS). Three hundred and seventy-six Lebanese participants, comprising 151 controls and 225 cases, were included. Clinical data were obtained from questionnaires and medical records. DNA isolated from peripheral blood was genotyped for ACE1 rs1799752, ACE2 rs2074192, TMPRSS2 rs75603675 and OAS1 rs107746771 using TaqMan assays, and for TMPRSS2 rs35074065 using Sanger Sequencing. Candidate genetic variants were analyzed in association with COVID-19 susceptibility, severity, hospitalization and hypoxia, using univariate and multivariate models. PRS constructed from the weighted sum of variants was evaluated in association with COVID-19 outcomes. In this study, there were no statistically significant differences in the frequencies of candidate variant alleles between cases, controls and within disease outcomes subgroups, after adjustment for confounders. PRS was not associated with COVID-19 susceptibility and hospitalization, it however significantly predicted COVID-19 severity (P = 0.01). This study highlights the importance of genetic testing for key host genes involved in COVID-19 life cycle and eventually measuring the PRS which proves to be an important tool for prognosis assessment in vulnerable individuals, potentially enhancing patient care.

Background: Antiseizure medications (ASM) exhibit considerable interindividual variability in terms of efficacy and adverse events. Genetic variation is thought to contribute to these differences in clinical outcomes. Specifically, the response to valproic acid (VPA), a widely used ASM, is influenced by multiple pharmacogenetic factors. However, and in contrast to other ASMs such as phenytoin and carbamazepine, there is a paucity of data on the association between VPA and various gene variants. The aim of this study was hence to evaluate the influence of candidate pharmacogenetic variants on VPA efficacy, toxicity and serum concentrations in a homogeneous cohort of patients newly diagnosed with genetic generalized epilepsies (GGE).Methods: In this prospective cohort study, demographic, clinical and treatment outcomes of GGE patients were retrieved from their medical records. Whole exome sequencing was performed in collaboration with Epi25. Gene variants associated with VPA efficacy, metabolism and toxicities were retrieved from PharmGKB. An analysis was then conducted to explore potential associations between these gene variants and VPA clinical outcomes.Results: Of the 166 patients included, 60 (36.1%) experienced treatment failure while 106 (63.9%) achieved treatment success. After adjusting for VPA maintenance dose, carriers of the rs3892097 (CYP2D6) variant were 2.5 times more likely to experience treatment failure compared to wildtype (p = 0.026). The rs1057910 variant (CYP2C9*3) was associated with increased serum VPA concentrations (p = 0.034). Moreover, the rs1137101 variant (LEPR gene, a metabolism regulator) was significantly associated with a higher risk of weight gain (regression coefficient of 3.430 [0.674; 6.186], p = 0.015) and a higher frequency of hair loss (OR = 3.394 [1.157; 9.956], p = 0.026), while the rs4480 variant (SOD2 gene, encoding for a mitochondrial scavenging enzyme) was correlated with a lower frequency of hair loss (OR = 0.276 [0.089; 0.858], p = 0.026).Conclusion: These findings highlight the role of genetic factors in VPA treatment and underscore the potential for developing therapeutic strategies to enhance patient outcomes and minimize adverse effects.

Pharmacogenomics (PGx) research and applications are of utmost relevance in Lebanon considering its population genetic diversity. Moreover, as a country with regional leadership in medicine and higher education, Lebanon holds a strong potential in contributing to PGx research and clinical implementation. In this manuscript, we first review and evaluate the available PGx research conducted in Lebanon, then describe the current status of PGx practice in Lebanon while reflecting on the local and regional challenges, and highlighting areas for action, and opportunities to move forward. We specifically expand on the status of PGx at the American University of Beirut Faculty of Medicine and Medical Center as a case study and guide for the further development of local and regional comprehensive PGx research, teaching, and clinical implementation programs. We also delve into the status of PGx knowledge and education, and prospects for further advancement such as with online courses and certificates.

Antiplatelets and anticoagulants are extensively used in cardiovascular medicine for the prevention and treatment of thrombosis in the venous and arterial circulations. Wide inter-individual variability has been observed in response to antiplatelets and anticoagulants, which triggered researchers to investigate the genetic basis of this variability. Data from extensive pharmacogenetic studies pointed to strong evidence of association between polymorphisms in candidate genes and the pharmacokinetics and pharmacodynamic action and clinical response of the antiplatelets clopidogrel and the anticoagulant warfarin. In this review, we conducted an extensive search on Medline for the time period of 2009–2023. We also searched the PharmGKB website for levels of evidence of variant-drug combinations and for drug labels and clinical guidelines. We focus on the pharmacogenetics of novel antiplatelets and anticoagulants while excluding acetylsalicylic acid, warfarin and heparins, and discuss the current knowledge with emphasis on the level of evidence.

The COVID-19 pandemic has forced changes in the delivery of medical education. We aimed to explore these changes and determine whether they will impact the future of medical education in any way. We invited leaders in medical education from all accessible US-based medical schools to participate in an online individual semi-structured interview. Representatives of 16 medical schools participated. They commented on the adequacy of online education for knowledge transfer, and the logistical advantages it offered, but decried its negative influence on social learning, interpersonal relationships and professional development of students, and its ineffectiveness for clinical education. Most participants indicated that they would maintain online learning for didactic purposes in the context of flipped classrooms but that a return to in-person education was essential for most other educational goals. Novel content will be introduced, especially in telemedicine and social medicine, and the students' roles and responsibilities in patient care and in curricular development may evolve in the future. This study is the first to document the practical steps that will be adopted by US medical schools in delivering medical education, which were prompted and reinforced by their experience during the COVID-19 pandemic.

Considerable efforts have been exerted to implement Pharmacogenomics (PGx), the study of interindividual variations in DNA sequence related to drug response, into routine clinical practice. In this article, we first briefly describe PGx and its role in improving treatment outcomes. We then propose an approach to initiate clinical PGx in the hospital setting. One should first evaluate the available PGx evidence, review the most relevant drugs, and narrow down to the most actionable drug-gene pairs and related variant alleles. This is done based on data curated and evaluated by experts such as the pharmacogenomics knowledge implementation (PharmGKB) and the Clinical Pharmacogenetics Implementation Consortium (CPIC), as well as drug regulatory authorities such as the US Food and Drug Administration (FDA) and European Medicinal Agency (EMA). The next step is to differentiate reactive point of care from preemptive testing and decide on the genotyping strategy being a candidate or panel testing, each of which has its pros and cons, then work out the best way to interpret and report PGx test results with the option of integration into electronic health records and clinical decision support systems. After test authorization or testing requirements by the government or drug regulators, putting the plan into action involves several stakeholders, with the hospital leadership supporting the process and communicating with payers, the pharmacy and therapeutics committee leading the process in collaboration with the hospital laboratory and information technology department, and healthcare providers (HCPs) ordering the test, understanding the results, making the appropriate therapeutic decisions, and explaining them to the patient. We conclude by recommending some strategies to further advance the implementation of PGx in practice, such as the need to educate HCPs and patients, and to push for more tests’ reimbursement. We also guide the reader to available PGx resources and examples of PGx implementation programs and initiatives.

The therapeutic efficacy of tamoxifen is predominantly mediated by its active metabolites 4‐hydroxy‐tamoxifen and endoxifen, whose formation is catalyzed by the polymorphic cytochrome P450 2D6 (CYP2D6). Yet, known CYP2D6 polymorphisms only partially determine metabolite concentrations in vivo. We performed the first cross‐ancestry genome‐wide association study with well‐characterized patients of European, Middle‐Eastern, and Asian descent (n = 497) to identify genetic factors impacting active and parent metabolite formation. Genome‐wide significant variants were functionally evaluated in an independent liver cohort (n = 149) and in silico. Metabolite prediction models were validated in two independent European breast cancer cohorts (n = 287, n = 189). Within a single 1‐megabase (Mb) region of chromosome 22q13 encompassing the CYP2D6 gene, 589 variants were significantly associated with tamoxifen metabolite concentrations, particularly endoxifen and metabolic ratio (MR) endoxifen/N‐desmethyltamoxifen (minimal P = 5.4E−35 and 2.5E−65, respectively). Previously suggested other loci were not confirmed. Functional analyses revealed 66% of associated, mostly intergenic variants to be significantly correlated with hepatic CYP2D6 activity or expression (ρ = 0.35 to −0.52), and six hotspot regions in the extended 22q13 locus impacting gene regulatory function. Machine learning models based on hotspot variants (n = 12) plus CYP2D6 activity score (AS) increased the explained variability (~ 9%) compared with AS alone, explaining up to 49% (median R²) and 72% of the variability in endoxifen and MR endoxifen/N‐desmethyltamoxifen, respectively. Our findings suggest that the extended CYP2D6 locus at 22q13 is the principal genetic determinant of endoxifen plasma concentration. Long‐distance haplotypes connecting CYP2D6 with adjacent regulatory sites and nongenetic factors may account for the unexplained portion of variability.