Metabolic implication of tigecycline as an efficacious second-line treatment for sorafenib-resistant hepatocellular carcinoma

Sorafenib represents the current standard of care for patients with advanced-stage hepatocellular carcinoma (HCC). However, acquired drug resistance occurs frequently during therapy and is accompanied by rapid tumor regrowth after sorafenib therapy termination. To identify the mechanism of this therapy-limiting growth resumption, we established robust sorafenib resistance HCC cell models that exhibited mitochondrial dysfunction and chemotherapeutic crossresistance. We found a rapid relapse of tumor cell proliferation after sorafenib withdrawal, which was caused by renewal of mitochondrial structures alongside a metabolic switch toward high electron transport system (ETS) activity. The translation-inhibiting antibiotic tigecycline impaired the biogenesis of mitochondrial DNA-encoded ETS subunits and limited the electron acceptor turnover required for glutamine oxidation. Thereby, tigecycline prevented the tumor relapse in vitro and in murine xenografts in vivo. These results offer a promising second-line therapeutic approach for advanced-stage HCC patients with progressive disease undergoing sorafenib therapy or treatment interruption due to severe adverse events

PI(18:1/18:1) is a SCD1-derived lipokine that limits stress signaling

Cytotoxic stress activates stress-activated kinases, initiates adaptive mechanisms, including the unfolded protein response (UPR) and autophagy, and induces programmed cell death. Fatty acid unsaturation, controlled by stearoyl-CoA desaturase (SCD)1, prevents cytotoxic stress but the mechanisms are diffuse. Here, we show that 1,2-dioleoyl-sn-glycero-3-phospho-(1’-myo-inositol) [PI(18:1/18:1)] is a SCD1-derived signaling lipid, which inhibits p38 mitogen-activated protein kinase activation, counteracts UPR, endoplasmic reticulum-associated protein degradation, and apoptosis, regulates autophagy, and maintains cell morphology and proliferation. SCD1 expression and the cellular PI(18:1/18:1) proportion decrease during the onset of cell death, thereby repressing protein phosphatase 2 A and enhancing stress signaling. This counter-regulation applies to mechanistically diverse death-inducing conditions and is found in multiple human and mouse cell lines and tissues of Scd1-defective mice. PI(18:1/18:1) ratios reflect stress tolerance in tumorigenesis, chemoresistance, infection, high-fat diet, and immune aging. Together, PI(18:1/18:1) is a lipokine that links fatty acid unsaturation with stress responses, and its depletion evokes stress signaling

Understanding the mechanism of action of pyrrolo[3,2-b]quinoxaline-derivatives as kinase inhibitors

The X-ray structure of the catalytic domain of the EphA3 tyrosine kinase in complex with a previously reported type II inhibitor was used to design two novel quinoxaline derivatives, inspired by kinase inhibitors that have reached clinical development. These two new compounds were characterized by an array of cell-based assays and gene expression profiling experiments. A global chemical proteomics approach was used to generate the drug-protein interaction profile, which suggested suitable therapeutic indications. Both inhibitors, studied in the context of angiogenesis and in vivo in a relevant lymphoma model, showed high efficacy in the control of tumor size

Patient perspectives on, and effects of, medication management in geriatric fallers (the EMMA study): protocol for a mixed-methods pre-post study

Introduction Pharmacotherapy is critical in geriatric fallers owing to the vulnerability of this population. Comprehensive medication management can be an important strategy to reduce the medication-related risk of falling in this patient group. Patient-specific approaches and patient-related barriers to this intervention have rarely been explored among geriatric fallers. This study will focus on establishing a comprehensive medication management process to provide better insights into patients’ individual perceptions regarding their fall-related medication as well as identifying organisational and medical-psychosocial effects and challenges of this intervention.Methods and analysis The study design is a complementary mixed-methods pre-post study which follows the approach of an embedded experimental model. Thirty fallers aged at least 65 years who were on five or more self-managed long-term drugs will be recruited from a geriatric fracture centre. The intervention consists of a five-step (recording, reviewing, discussion, communication, documentation) comprehensive medication management, which focuses on reducing the medication-related risk of falling. The intervention is framed using guided semi-structured pre-post interventional interviews, including a follow-up period of 12 weeks. These interviews will assess patients’ perceptions of falls, medication-related risks and gauge the postdischarge acceptability and sustainability of the intervention. Outcomes of the intervention will be measured based on changes in the weighted and summated Medication Appropriateness Index score, number of fall-risk-increasing drugs and potentially inadequate medication according to the Fit fOR The Aged and PRISCUS lists. Qualitative and quantitative findings will be integrated to develop a comprehensive understanding of decision-making needs, the perspective of geriatric fallers and the effects of comprehensive medication management.Ethics and dissemination The study protocol was approved by the local ethics committee of Salzburg County, Austria (ID: 1059/2021). Written informed consent will be obtained from all patients. Study findings will be disseminated through peer-reviewed journals and conferences.Trial registration number DRKS00026739