Influence of CYP3A5 and ABCB1 gene polymorphisms and other factors on tacrolimus dosing in Caucasian liver and kidney transplant patients

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Pharmacogenetic considerations for optimizing tacrolimus dosing in liver and kidney transplant patients

The introduction of tacrolimus in clinical practice has improved patient survival after organ transplant. However, despite the long use of tacrolimus in clinical practice, the best way to use this agent is still a matter of intense debate. The start of the genomic era has generated new research areas, such as pharmacogenetics, which studies the variability of drug response in relation to the genetic factors involved in the processes responsible for the pharmacokinetics and/or the action mechanism of a drug in the body. This variability seems to be correlated with the presence of genetic polymorphisms. Genotyping is an attractive option especially for the initiation of the dosing of tacrolimus; also, unlike phenotypic tests, the genotype is a stable characteristic that needs to be determined only once for any given gene. However, prospective clinical studies must show that genotype determination before transplantation allows for better use of a given drug and improves the safety and clinical efficacy of that medication. At present, research has been able to reliably show that the CYP3A5 genotype, but not the CYP3A4 or ABCB1 ones, can modify the pharmacokinetics of tacrolimus. However, it has not been possible to incontrovertibly show that the corresponding changes in the pharmacokinetic profile are linked with different patient outcomes regarding tacrolimus efficacy and toxicity. For these reasons, pharmacogenetics and individualized medicine remain a fascinating area for further study and may ultimately become the face of future medical practice and drug dosing

The GSK3\u3b2 inhibitor BIS I reverts YAP-dependent EMT signature in PDAC cell lines by decreasing SMADs expression level

The Yes-associated protein, YAP, is a transcriptional co-activator, mediating the Epithelial to Mesenchymal Transition program in pancreatic ductal adenocarcinoma (PDAC). With the aim to identify compounds that can specifically modulate YAP functionality in PDAC cell lines, we performed a small scale, drug-based screening experiment using YAP cell localization as the read-out. We identified erlotinib as an inducer of YAP cytoplasmic localization, an inhibitor of the TEA luciferase reporter system and the expression of the bona fide YAP target gene, Connective Tissue Growth Factor CTGF. On the other hand, BIS I, an inhibitor of PKC\u3b4 and GSK3\u3b2, caused YAP accumulation into the nucleus. Activation of \u3b2-catenin reporter and interfering experiments show that inhibition of the PKC\u3b4/GSK3\u3b2 pathway triggers YAP nuclear accumulation inducing YAP/TEAD transcriptional response. Inhibition of GSK3\u3b2 by BIS I reduced the expression levels of SMADs protein and reduced YAP contribution to EMT. Notably, BIS I reduced proliferation, migration and clonogenicity of PDAC cells in vitro, phenocopying YAP genetic down-regulation. As shown by chromatin immunoprecipitation experiments and YAP over-expressing rescue experiments, BIS I reverted YAP-dependent EMT program by modulating the expression of the YAP target genes E-cadherin, vimentin, CTGF and of the newly identified target, CD133. In conclusion, we identified two different molecules, erlotinib and BIS I, modulating YAP functionality although via different mechanisms of action, with the second one specifically inhibiting the YAP-dependent EMT program in PDAC cell lines

Cancer cell metabolic plasticity allows resistance to NAMPT inhibition but invariably induces dependence on LDHA

Background: Inhibitors of nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in NAD+ biosynthesis from nicotinamide, exhibit anticancer effects in preclinical models. However, continuous exposure to NAMPT inhibitors, such as FK866, can induce acquired resistance. Methods: We developed FK866-resistant CCRF-CEM (T cell acute lymphoblastic leukemia) and MDA MB231 (breast cancer) models, and by exploiting an integrated approach based on genetic, biochemical, and genome wide analyses, we annotated the drug resistance mechanisms. Results: Acquired resistance to FK866 was independent of NAMPT mutations but rather was based on a shift towards a glycolytic metabolism and on lactate dehydrogenase A (LDHA) activity. In addition, resistant CCRF-CEM cells, which exhibit high quinolinate phosphoribosyltransferase (QPRT) activity, also exploited amino acid catabolism as an alternative source for NAD+ production, becoming addicted to tryptophan and glutamine and sensitive to treatment with the amino acid transport inhibitor JPH203 and with L-asparaginase, which affects glutamine exploitation. Vice versa, in line with their low QPRT expression, FK866-resistant MDA MB231 did not rely on amino acids for their resistance phenotype. Conclusions: Our study identifies novel mechanisms of resistance to NAMPT inhibition, which may be useful to design more rational strategies for targeting cancer metabolism

Evidence-based application of explicit criteria to assess the appropriateness of geriatric prescriptions at admission and hospital stay.

BackgroundInappropriate prescribing in the elderly is a critical issue in primary care, causing a higher risk of Adverse Drug Reactions (ADRs) and resulting in major patient safety concerns. At international level, many tools have been developed to identify Potentially Inappropriate Medications (PIMs).ObjectiveThe aim of this study was the application of Beers, Screening Tool of Older People's Prescriptions (STOPP)/Screening Tool to Alert to Right Treatment (START) and Improving Prescribing in the Elderly Tool (IPET) criteria as key tool to improve the quality of prescribing.MethodsA retrospective study was conducted using the aforementioned criteria. Two different cohorts of elderly patients were enrolled between January 2015 and December 2016, 1800 at admission and 1466 at hospital stay. The index of each criterion divided by politherapy were correlated with comorbidities (Pearson correlation). A comparison was made between admission and hospital stay through a Student's t test of the average of the index.ResultsThe Proton Pump Inhibitors (PPIs) were the most prescribed PIMs according Beers criteria in both patient cohorts (56%). The most detected drug-drug and drug-disease interactions at admission and at hospital stay were 3 or more drugs active on the Central Nervous System (CNS) as they can predispose to fall-risk. The most detected PIMs with STOPP criteria at admission were PPIs administered for more than 8 weeks. Inhaled β2-agonists or antimuscarinics were the most prescribed Potential Prescription Omissions (PPOs) according to START criteria. Nonsteroidal Anti-inflammatory Drugs (NSAIDs) in patients with high blood pressure were the most detected PIMs according to IPET criteria during hospital stay. A significant correlation between the comorbidities and the all index at hospital stay, while at admission there was no significant correlation for Beers and IPET index.ConclusionThe prescriptive criteria were a useful tool for assessing the quality of prescriptions in the geriatric population and identifying their critical issues

Fasting potentiates the anticancer activity of tyrosin kinase inhibitors by strenghtening MAPK signalling inhibition.

Tyrosine kinase inhibitors (TKIs) are now the mainstay of treatment in many types of cancer. However, their benefit is frequently short-lived, mandating the search for safe potentiation strategies. Cycles of fasting enhance the activity of chemo-radiotherapy in preclinical cancer models and dietary approaches based on fasting are currently explored in clinical trials. Whether combining fasting with TKIs is going to be potentially beneficial remains unknown. Here we report that starvation conditions increase the ability of commonly administered TKIs, including erlotinib, gefitinib, lapatinib, crizotinib and regorafenib, to block cancer cell growth, to inhibit the mitogen-activated protein kinase (MAPK) signaling pathway and to strengthen E2F-dependent transcription inhibition. In cancer xenografts models, both TKIs and cycles of fasting slowed tumor growth, but, when combined, these interventions were significantly more effective than either type of treatment alone. In conclusion, cycles of fasting or of specifically designed fasting-mimicking diets should be evaluated in clinical studies as a means to potentiate the activity of TKIs in clinical use

EIF2A-dependent translational arrest protects leukemia cells from the energetic stress induced by NAMPT inhibition

Cell-cycle analysis andClick-iTdetection of RNA and Protein synthesis. A) Cell-cycle analysis with PI staining of the nuclei after 48 h of treatment. Overnight serum starvation is shown as a positive control of induced cell cycle synchronization in G0/G1 phase. Cell phase analysis was done with ModFit LT 3.2 software by using the Sync Wizard model (30000 cells/sample in biological duplicate). B) Jurkat cells were treated for 48 h with or without (Mock) the indicated concentration of FK866 or for 3 h with 5 μM Actinomycin D, an RNA synthesis blocking agent, then subjected to Click-it biochemistry and flow-cytometry analyses including 7-AAD to identify living cells. C) Jurkat cells were treated for 48 h with or without (Mock) the indicated concentration of FK866 or for 3 h with 350 μM Cycloheximide, as a positive control for protein synthesis inhibition, then stained as in B. In B and C. Experiments were carried out on two biological replicates (50000 events/sample). (PDF 1562 kb

Efficacy and Safety of Remdesivir in Adult Solid Organ Transplant Recipients: A Scoping Review

The SARS-CoV-2 infection has been associated with important mortality, particularly in immunocompromised patients, including solid organ transplant (SOT) recipients. Remdesivir (RDV) is an antiviral drug that has proven to be effective in reducing the replication of the virus in host cells, by which it may reduce the progression of symptoms and, consequently, the length of hospital stay and mortality. Randomized controlled trials have evaluated its use in the general population but never in SOT recipients. For the first time in this review, the safety and efficacy of RDV is evaluated in this specific population. The literature research was conducted using PubMed/MEDLINE and Scopus databases from 1 January 2020 to 24 November 2023, and 23 studies were analyzed. Although no clinical studies specifically evaluating this population have been conducted yet, RDV is likely safe for SOT patients when compared to the general population, so prescribers should consider utilizing RDV in SOT patients who are at high risk for progression to severe COVID-19. Future research will allow for the confirmation of the observed results and the acquisition of broader and clearer data regarding the safety and efficacy of the drug in this specific setting