Direct Inhibitor Research Articles

Sphingosine d18:1 promotes nonalcoholic steatohepatitis by inhibiting macrophage HIF-2α

Non-alcoholic steatohepatitis (NASH) is a severe type of the non-alcoholic fatty liver disease (NAFLD). NASH is a growing global health concern due to its increasing morbidity, lack of well-defined biomarkers and lack of clinically effective treatments. Using metabolomic analysis, the most significantly changed active lipid sphingosine d18:1 [So(d18:1)] is selected from NASH patients. So(d18:1) inhibits macrophage HIF-2α as a direct inhibitor and promotes the inflammatory factors secretion. Male macrophage-specific HIF-2α knockout and overexpression mice verified the protective effect of HIF-2α on NASH progression. Importantly, the HIF-2α stabilizer FG-4592 alleviates liver inflammation and fibrosis in NASH, which indicated that macrophage HIF-2α is a potential drug target for NASH treatment. Overall, this study confirms that So(d18:1) promotes NASH and clarifies that So(d18:1) inhibits the transcriptional activity of HIF-2α in liver macrophages by suppressing the interaction of HIF-2α with ARNT, suggesting that macrophage HIF-2α may be a potential target for the treatment of NASH.

A retrospective review of recurrent venous thromboembolism in patients with cancer with direct factor Xa inhibitors.

e24136 Background: Venous thromboembolism (VTE) in cancer patients is a significant cause of morbidity and mortality. People with malignancies are at an increased risk of thrombosis compared to the normal population. Regimens that include platinum-based agents and vascular endothelial growth factor (VEGF) inhibitors have a higher risk of thromboembolism1. The recent ASCO 2023 guidelines for VTE prophylaxis and treatment have advised that direct factor Xa inhibitors are a suitable option for initial and long-term treatment for VTE, given patient preference of oral over subcutaneous administration of anti coagulation2. In our retrospective review of a single centre in Western Australia, we have identified twelve patients who have developed thromboembolic events whilst on direct oral anticoagulation. Methods: Electronic patient records were reviewed for oncology patients attending between 2016 and 2023 at a single centre in Western Australia.Diagnosis of VTE and subsequent treatment was confirmed from radiology and medication records. Twelve patients were identified, and data was recorded and analysed. Results: 12 patients were identified with recurrent VTE whilst on direct factor Xa inhibitors. The median age was 59.5 years (range 50-71). The most common associated malignancies were pancreatic, ovarian and lung cancer. Others include breast, vulval, colon and gastroesophageal cancer. Two thirds of patients were metastatic at diagnosis (n = 8). Common sites of thrombosis include the lower limbs at both initial [n = 6] and recurrent [n = 4] presentation. All patients were treated with therapeutic doses of rivaroxaban (n = 8) or apixaban (n = 4) at the time of of initial or recurrent thrombotic event. Median time to initial thrombotic event was 4.5 months from diagnosis compared to recurrent VTE [5 months]. All patients were changed to either LMWH (n = 10) or unfractionated heparin (n = 2). Ten patients [83.3%] did not have further thrombosis post switching to heparin. One patient had recurrent pulmonary emboli on imaging despite heparin administration, and the other had an IVC filter insertion. Conclusions: VTE is a common complication for oncology patients. Given our results, clinicians should be suspicious for recurrent VTE for patients on direct factor Xa inhibitors. There is an argument for enoxaparin or dalteparin to be better options, particularly in those high risk. Whilst patient preference for an oral option is desirable, further investigation is needed to directly compare the differing direct factor Xa inhibitors and the rates of VTE recurrence.

NOS2 and COX-2 Co-Expression Promotes Cancer Progression: A Potential Target for Developing Agents to Prevent or Treat Highly Aggressive Breast Cancer.

Nitric oxide (NO) and reactive nitrogen species (RNS) exert profound biological impacts dictated by their chemistry. Understanding their spatial distribution is essential for deciphering their roles in diverse biological processes. This review establishes a framework for the chemical biology of NO and RNS, exploring their dynamic reactions within the context of cancer. Concentration-dependent signaling reveals distinctive processes in cancer, with three levels of NO influencing oncogenic properties. In this context, NO plays a crucial role in cancer cell proliferation, metastasis, chemotherapy resistance, and immune suppression. Increased NOS2 expression correlates with poor survival across different tumors, including breast cancer. Additionally, NOS2 can crosstalk with the proinflammatory enzyme cyclooxygenase-2 (COX-2) to promote cancer progression. NOS2 and COX-2 co-expression establishes a positive feed-forward loop, driving immunosuppression and metastasis in estrogen receptor-negative (ER-) breast cancer. Spatial evaluation of NOS2 and COX-2 reveals orthogonal expression, suggesting the unique roles of these niches in the tumor microenvironment (TME). NOS2 and COX2 niche formation requires IFN-γ and cytokine-releasing cells. These niches contribute to poor clinical outcomes, emphasizing their role in cancer progression. Strategies to target these markers include direct inhibition, involving pan-inhibitors and selective inhibitors, as well as indirect approaches targeting their induction or downstream effectors. Compounds from cruciferous vegetables are potential candidates for NOS2 and COX-2 inhibition offering therapeutic applications. Thus, understanding the chemical biology of NO and RNS, their spatial distribution, and their implications in cancer progression provides valuable insights for developing targeted therapies and preventive strategies.

ILX-002 A Direct HbS Polymerization Inhibitor for the Treatment of Sickle Cell Disease

ILX-002 A Direct HbS Polymerization Inhibitor for the Treatment of Sickle Cell Disease

A phase 1 trial evaluating the safety, tolerability, PK, and preliminary efficacy of QTX3034, an oral G12D-preferring multi-KRAS inhibitor, in patients with solid tumors with KRASG12D mutation.

TPS3172 Background: KRAS is one of the most mutated driver oncogenes across solid tumors, and KRAS G12D missense mutations have high prevalence in pancreatic, colorectal (CRC), and endometrial cancers. QTX3034 is a highly-selective, non-covalent, orally bioavailable, multi-KRAS inhibitor with potent activity across several KRAS variants, particularly G12D. QTX3034 binds to GDP-bound forms of mutant and wild-type KRAS with (sub)nanomolar affinities, allosterically inhibiting its conversion to the active state. QTX3034 inhibits KRAS signaling in in vitro studies and displays synergy with EGFR inhibitors. In vivo evaluation of QTX3034 resulted in significant tumor growth inhibition across various tumor models, with tumor regressions observed in 100% of animals in both HPAC pancreatic and GP2D colorectal KRAS G12D xenograft models. QTX3034 exhibits brain penetration in preclinical studies, including an orthotopic model of intracranial efficacy. This clinical trial is now enrolling patients with advanced solid tumors harboring a KRASG12D mutation. Methods: This is a first-in-human, multicenter, open-label phase 1 study in adult patients with advanced solid tumors with KRASG12D mutations, without prior direct KRAS inhibitor treatment (NCT06227377). The primary objectives are to evaluate the safety and tolerability and to determine maximum tolerated dose (MTD) and/or recommended phase 2 dose (RP2D) of QTX3034 alone, and in combination with cetuximab. Secondary objectives are characterization of the PK profile and preliminary antitumor activity. Part 1 consists of two dose-escalation arms: QTX3034 monotherapy (advanced solid tumors) and QTX3034 plus cetuximab (CRC) and will enroll 3-4 subjects per cohort in a Bayesian Logistic Regression Model (BLRM) design. QTX3034 will be administered orally in 21-day cycles until disease progression, intolerable toxicity, or withdrawal from treatment. Exploratory paired biopsies will be collected in Cycle 2 in a group of patients in the dose-escalation phase. Serial ctDNA will be collected in all patients. Following identification of a RP2D, QTX3034 will be evaluated in dose-expansion cohorts of up to 30 patients with various KRASG12D mutated tumor types to determine preliminary activity: pancreatic cancer, CRC, non-small cell lung cancer and endometrial cancer. To further optimize the recommended dose, patients will be randomized between two dose levels in the pancreatic cancer cohort. QTX3034 plus cetuximab will be explored following identification of a recommended combination dose in patients with CRC. Clinical trial information: NCT06227377 .

Utilising the New Technology Add-on Payment (NTAP): Improving Medicare-insured patients’ access to innovative therapeutics

Andexanet alfa (Andexxa) is the first reversal agent for direct factor Xa inhibitors. It qualified as a new, novel therapeutic for the New Technology Add-on Payment (NTAP) reimbursement from the Centers for Medicare and Medicaid Services (CMS) in October 2018. This paper is the first analysis of a healthcare system (HCS) reporting its implementation and utilisation of the NTAP for a new therapeutic. The number of patients treated with Andexxa at the level 1 trauma centre of southern New Jersey, Cooper University Hospital (CUH) was analysed. This paper highlights the successful implementation of Andexxa as a treatment option for (non)traumatic intracranial haemorrhage and acute, nongastrointestinal haemorrhage requiring surgical management at CUH. This paper looked at how well CUH obtained the Andexxa NTAP from CMS for Medicare patients. During the 4-year reimbursement period, CUH treated a total of 88 patients with Andexxa, of which 53 were Medicare patients treated before the expiry of the Andexxa NTAP. The study found that CUH received NTAP for 81 per cent of Andexxa-treated Medicare patients and that CUH received the maximal NTAP amount of US$18,281.25 for 43 per cent of those same patients. The paper discusses how a large trauma centre implemented and received the NTAP for Andexxa and evaluates the effect of cost on reimbursement amounts during the Andexxa NTAP period. Finally, this paper should help healthcare providers, stakeholders and administrators better understand the process through which to obtain NTAP reimbursements from CMS and improve their HCS with new, innovative therapies for their patients.

A first-in-human, phase 1/2 trial of FOG-001, a β-catenin:TCF antagonist, in patients with locally advanced or metastatic solid tumors.

TPS3175 Background: The Wnt/β-catenin pathway is a frequently activated oncogenic pathway and a well-described driver of many cancers. FOG-001 is designed to be a first-in-class direct inhibitor of β-catenin that blocks β-catenin’s interaction with the T-cell factor (TCF) family of transcription factors. Preclinical studies have indicated FOG-001 can cause tumor growth inhibition and regression by disrupting β-catenin-dependent signaling. FOG-001 is unique from previously reported Wnt/β-catenin pathway modulators as it is designed to directly inhibit TCF transcription factor and β-catenin interaction, the most downstream node in the Wnt pathway. It is hypothesized FOG-001 will abrogate the hyperactivation of the Wnt pathway that is driven by most known pathway mutations. Methods: This first-in-human, Phase 1/2, multicenter, open-label, dose escalation (Parts 1a and 1b) and dose-expansion (Part 2) study is evaluating the safety/tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and antitumor activity of FOG-001 in patients with advanced or metastatic solid tumors. Patients with the following tumor types are eligible: microsatellite stable (MSS) colorectal cancer (CRC) or any solid tumor with documented Wnt pathway activating mutation (WPAM) (Part 1a), MSS CRC only (Part 1b) and MSS CRC, gastric/gastroesophageal (GEJ) cancer, non-small cell lung cancer (NSCLC), and any solid tumors with documented WPAM in Part 2. Patients must have received ≥1 prior systemic anticancer therapy(ies) and be ineligible for curative surgery or curative chemoradiation. In Part 1, FOG-001 is administered at escalating doses via intravenous (IV) infusion on Days 1, 8, 15, and 22 of each 4-week cycle; additional dosing regimens may be explored. After selection of the preliminary recommended Phase 2 dose(s) (pRP2D) and regimen(s) in Part 1, the following cohorts will be enrolled to receive FOG-001 at the pRP2D in Part 2: (2a) MSS CRC; (2b) NSCLC with documented WPAM in adenomatous polyposis coli (APC) or β-catenin; (2c) gastric/GEJ cancer with documented WPAM in APC or β-catenin; and (2d) solid tumors with ≥1 documented WPAM in any predefined Wnt pathway genes. The primary endpoints are safety/tolerability (Parts 1 and 2), and also preliminary antitumor activity (objective response rate) (Part 2). Secondary endpoints are PK, PD, and additional antitumor activity assessments. Enrollment in Part 1 is ongoing. Clinical trial information: NCT05919264 .

WS14.02 Tezacaftor is a direct inhibitor of sphingolipid delta-4 desaturase enzyme (DEGS)

WS14.02 Tezacaftor is a direct inhibitor of sphingolipid delta-4 desaturase enzyme (DEGS)

Trends in Venous Thromboembolism and Chemoprophylaxis Utilization in Elective Total Knee Arthroplasty From 2011 to 2020

BackgroundVenous thromboembolism (VTE) is a feared complication of joint arthroplasty, leading to recent clinical practice guidelines aimed at VTE prevention and prophylaxis. However, limited studies have examined national changes in practice regarding chemoprophylaxis and the resultant changes in VTE rates. The purpose of this study was to identify: (1) the temporal trends in thrombotic complications; and (2) changes in chemoprophylaxis utilization in patients undergoing elective total knee arthroplasty (TKA). MethodsA retrospective study was conducted using a large all-payer claims dataset. Patients who underwent osteoarthritis-indicated TKA between 2011 and 2020 were identified. Annual rates of VTE, including deep vein thrombosis and pulmonary embolism, within 90 days of TKA were determined. Utilization patterns for postoperative aspirin and anticoagulant medications were observed. Temporal trends were analyzed with linear regression and the calculation of the cumulative annual growth rate. Multivariable logistic regression was conducted to account for the effects of age and comorbidities. ResultsA total of 1,263,351 TKA patients were identified between 2011 and 2020. There were significant reductions in VTE rates (2.9% in 2011 to 1.8% in 2020), deep vein thrombosis rates (2.0% in 2011 to 1.3% in 2020), and pulmonary embolism rates (1.1% in 2011 to 0.6% in 2020). Postoperative utilization of aspirin increased from 5.9% in 2011 to 53.2% in 2020, whereas utilization of anticoagulants decreased from 94.1% in 2011 to 46.8% in 2020. Among anticoagulants, direct factor Xa inhibitors had the greatest increase in utilization (4.6 to 69.7%). The average reimbursement associated with VTE after TKA decreased from $18,061 in 2011 to $7,835 in 2020. ConclusionsThe incidence rate and economic burden of VTE after TKA have significantly declined since 2011. There has been a trend toward increased aspirin and direct oral anticoagulant utilization for postoperative chemoprophylaxis. Level of EvidenceLevel III.

Cardioprotective properties of OMT-28, a synthetic analog of omega-3 epoxyeicosanoids

OMT-28 is a metabolically robust small molecule developed to mimic the structure and function of omega-3 epoxyeicosanoids. However, it remained unknown to what extent OMT-28 also shares the cardioprotective and anti-inflammatory properties of its natural counterparts. To address this question, we analyzed the ability of OMT-28 to ameliorate hypoxia/reoxygenation (HR)-injury and lipopolysaccharide (LPS)-induced endotoxemia in cultured cardiomyocytes. Moreover, we investigated the potential of OMT-28 to limit functional damage and inflammasome activation in isolated perfused mouse hearts subjected to ischemia/reperfusion (IR) injury. In the HR model, OMT-28 (1μM) treatment largely preserved cell viability (about 75 versus 40% with the vehicle) and mitochondrial function as indicated by the maintenance of NAD+/NADH-, ADP/ATP-, and respiratory control ratios. Moreover, OMT-28 blocked the HR-induced production of mitochondrial reactive oxygen species. Pharmacological inhibition experiments suggested that Gαi, PI3K, PPARα, and Sirt1 are essential components of the OMT-28-mediated pro-survival pathway. Counteracting inflammatory injury of cardiomyocytes, OMT-28 (1μM) reduced LPS-induced increases in TNFα protein (by about 85% versus vehicle) and NF-κB DNA binding (by about 70% versus vehicle). In the exvivo model, OMT-28 improved post-IR myocardial function recovery to reach about 40% of the baseline value compared to less than 20% with the vehicle. Furthermore, OMT-28 (1μM) limited IR-induced NLRP3 inflammasome activation similarly to a direct NLRP3 inhibitor (MCC950). Overall, this study demonstrates that OMT-28 possesses potent cardio-protective and anti-inflammatory properties supporting the hypothesis that extending the bioavailability of omega-3 epoxyeicosanoids may improve their prospects as therapeutic agents.

Discovery of Nine Dipeptidyl Peptidase-4 Inhibitors from Coptis chinensis Using Virtual Screening, Bioactivity Evaluation, and Binding Studies.

The objective of this study was to identify multiple alkaloids in Coptis chinensis that demonstrate inhibitory activity against DPP-4 and systematically evaluate their activity and binding characteristics. A combined strategy that included molecular docking, a DPP-4 inhibition assay, surface plasmon resonance (SPR), and a molecular dynamics simulation technique was employed. The results showed that nine alkaloids in Coptis chinensis directly inhibited DPP-4, with IC50 values of 3.44-53.73 μM. SPR-based binding studies revealed that these alkaloids display rapid binding and dissociation characteristics when interacting with DPP-4, with KD values ranging from 8.11 to 29.97 μM. A molecular dynamics analysis revealed that equilibrium was rapidly reached by nine DPP-4-ligand systems with minimal fluctuations, while binding free energy calculations showed that the ∆Gbind values for the nine test compounds ranged from -31.84 to -16.06 kcal/mol. The most important forces for the binding of these alkaloids with DPP-4 are electrostatic interactions and van der Waals forces. Various important amino acid residues, such as Arg125, His126, Phe357, Arg358, and Tyr547, were involved in the inhibition of DPP-4 by the compounds, revealing a mechanistic basis for the further optimization of these alkaloids as DPP-4 inhibitors. This study confirmed nine alkaloids as direct inhibitors of DPP-4 and characterized their binding features, thereby providing a basis for further research and development on novel DPP-4 inhibitors.

Upregulation of GPX4 drives ferroptosis resistance in scleroderma skin fibroblasts

The pathogenesis of systemic sclerosis (SSC) fibrosis involves the rapid proliferation of skin fibroblasts, and current anti-fibrotic treatments are limited. This study investigated the relationship between ferroptosis and SSC skin fibroblasts. We observed that erastin-induced ferroptosis was suppressed in SSC fibroblasts. RSL3, a direct inhibitor of Glutathione Peroxidase 4 (GPX4), significantly reduced the viability of the fibroblasts, and upregulation of GPX4 in the SSC fibroblasts contributed to ferroptosis resistance. Furthermore, we demonstrated that transferrin receptor 1 (TfR1) was a crucial transporter for iron deposition in the fibroblasts. Collectively, our results highlight that GPX4 inhibition could enhance the sensitivity to ferroptosis by SSC fibroblasts, which showed distinct characteristics of iron metabolism that were not observed in normal fibroblasts in this study. Taken together, these results suggest that targeting ferroptosis could be a therapeutic strategy for the treatment of SSC.

Minimally modified human blood coagulation factor X to bypass direct factor Xa inhibitors

BackgroundDirect oral factor (F)Xa inhibitors are widely used as alternatives to conventional vitamin K antagonists in managing venous thromboembolism and nonvalvular atrial fibrillation. Unfortunately, bleeding-related adverse events remain a major concern in clinical practice. In case of bleeding or emergency surgery, rapid-onset reversal agents may be required to counteract the anticoagulant activity. ObjectivesThe ability of FXa variants to bypass the direct oral FXa inhibitors was assessed. MethodsHuman FXa variants were generated through substitution of phenylalanine 174 (F174) for either alanine, isoleucine, or serine. FXa variants were stably expressed in HEK293 cells and purified to homogeneity using ion-exchange chromatography. ResultsF174-substituted human FX variants demonstrated efficacy in restoring thrombin generation in plasma containing direct FXa inhibitors (apixaban, rivaroxaban, edoxaban). Their ability to bypass the anticoagulant effects stems from a significantly reduced sensitivity for the direct FXa inhibitors due to a decrease in binding affinity determined using molecular dynamics simulations and free energy computation. Furthermore, F174 modification resulted in a partial loss of inhibition by tissue factor pathway inhibitor, enhancing the procoagulant effect of F174-substituted FX. Consequently, the F174A- and F174S-substituted FX variants effectively counteracted the effects of 2 widely used anticoagulants, apixaban and rivaroxaban, in plasma of atrial fibrillation and venous thromboembolism patients. ConclusionThese human FX variants have the potential to serve as a rescue reversal strategy to overcome the effect of direct FXa inhibitors in case of life-threatening bleeding events or emergency surgical interventions.

Perioperative Management in Patients with Atrial Fibrillation Treated with Non-Vitamin K Antagonist Oral Anticoagulants Undergoing Minor Bleeding Risk Procedure: Rationale and Protocol for the PERIXa Study.

While treatment interruption of non-vitamin K antagonist oral anticoagulants (NOACs) for elective surgery or procedures among patients with atrial fibrillation (AF) is becoming more prevalent, there remains insufficient evidence regarding the optimal perioperative management of NOACs, particularly procedures with minor bleeding risks. This study aims to evaluate the safety and effectiveness of a simplified, standardized protocol for perioperative management of direct factor Xa inhibitors in patients, with AF undergoing procedures associated with minor bleeding risk. This multicenter, prospective single-arm registry study plans to enroll patients undergoing procedures with minor bleeding risk who were prescribed direct factor Xa inhibitors for AF. The procedures with minor bleeding risk will include gastrointestinal endoscopy for diagnostic purposes, selected dental procedures, and ocular surgery for cataracts or glaucoma. For apixaban, patients will withhold the last evening dose and resume either from the evening dose of the procedure day or the following morning, depending on the bleeding risk of the patient. For edoxaban or rivaroxaban, patients will withhold only a single dose on the procedure day. The primary outcome is the occurrence of major bleeding events within 30 days. Secondary outcomes include systemic thromboembolism, all-cause mortality, and a composite of major and clinically relevant non-major bleeding events. This study has the potential to generate evidence regarding the safety of perioperative management for patients, with AF undergoing procedures associated with minor bleeding risk. Clinicaltrials.gov: NCT05801068.

Salvianolic acid B inhibits thrombosis and directly blocks the thrombin catalytic site

BackgroundSalvianolic acid B (SAB) is a major component of Salvia miltiorrhiza root (Danshen), widely used in East/Southeast Asia for centuries to treat cardiovascular diseases. Danshen depside salt, 85% of which is made up of SAB, is approved in China to treat chronic angina. Although clinical observations suggest that Danshen extracts inhibited arterial and venous thrombosis, the exact mechanism has not been adequately elucidated. ObjectiveTo delineate the antithrombotic mechanisms of SAB. MethodsWe applied platelet aggregation and coagulation assays, perfusion chambers, and intravital microscopy models. The inhibition kinetics and binding affinity of SAB to thrombin are measured by thrombin enzymatic assays, intrinsic fluorescence spectrophotometry, and isothermal titration calorimetry. We used molecular in silico docking models to predict the interactions of SAB with thrombin. ResultsSAB dose-dependently inhibited platelet activation and aggregation induced by thrombin. SAB also reduced platelet aggregation induced by adenosine diphosphate and collagen. SAB attenuated blood coagulation by modifying fibrin network structures and significantly decreased thrombus formation in mouse cremaster arterioles and perfusion chambers. The direct SAB-thrombin interaction was confirmed by enzymatic assays, intrinsic fluorescence spectrophotometry, and isothermal titration calorimetry. Interestingly, SAB shares key structural similarities with the trisubstituted benzimidazole class of thrombin inhibitors, such as dabigatran. Molecular docking models predicted the binding of SAB to the thrombin active site. ConclusionOur data established SAB as the first herb-derived direct thrombin catalytic site inhibitor, suppressing thrombosis through both thrombin-dependent and thrombin-independent pathways. Purified SAB may be a cost-effective agent for treating arterial and deep vein thrombosis.

Tezacaftor is a direct inhibitor of sphingolipid delta-4 desaturase enzyme (DEGS)

BackgroundWe recently demonstrated that 48 h exposure of primary human bronchial epithelial (hBE) cells, obtained from both CF (F508del homozygous) and non-CF subjects, to the triple drug combination Elexacaftor/Tezacaftor/Ivacaftor (ETI) results in a CFTR genotype-independent modulation of the de novo synthethic pathway of sphingolipids, with an accumulation of dihydroceramides (dHCer). Since dHCer are converted into ceramides (Cer) by the action of a delta-4 sphingolipid desaturase (DEGS) enzyme, we aimed to better understand this off-target effect of ETI (i.e., not related to CFTR rescue) MethodshBE cells, both F508del and wild-type, were cultured to create fully differentiated bronchial epithelia. We analyzed Cer and dHCer using an LC-MS based method previously developed by our lab. DEGS expression levels in differentiated hBE cells lysates were quantified by western blot analysis. ResultsWe demonstrated that 1) dHCer accumulate in hBE with time following prolonged ETI exposure, that 2) similar inhibition occurs in wild-type primary human hepatocytes and that 3) this does not result in an alteration of DEGS expression. We then proved that 4) ETI is a direct inhibitor of DEGS, that 5) Tezacaftor is the molecule responsible for this effect, that 6) the inhibition is concentration dependent. Finally, after repeated oral administration of ETI to naïve, non-CF, mice, we observed a slight accumulation of dHCer in the brain. ConclusionsWe believe that further investigations on Tezacaftor should be envisaged, particularly for the use of ETI during pregnancy, breastfeeding and in the early stages of development. DEGS dysfunction and dHCer accumulation causes impairment in the development of the nervous system, due to a derangement in myelin formation and maintenance.

In Silico Discovery of Stapled Peptide Inhibitor Targeting the Nur77-PPARγ Interaction and Its Anti-Breast-Cancer Efficacy.

The binding of peroxisome proliferator-activated receptor γ (PPARγ) to the orphan nuclear receptor Nur77 facilitates the ubiquitination and degradation of Nur77, and leads to aberrant fatty acid uptake for breast cancer progression. Because of its crucial role in clinical prognosis, the interaction between Nur77 and PPARγ is an attractive target for anti-breast-cancer therapy. However, developing an inhibitor of the Nur77-PPARγ interaction poses a technical challenge due to the absence of the crystal structure of PPARγ and its corresponding interactive model with Nur77. Here, ST-CY14, a stapled peptide,is identified as a potent modulator of Nur77 with a KD value of 3.247×10-8M by in silico analysis, rational design, and structural modification. ST-CY14 effectively increases Nur77 protein levels by blocking the Nur77-PPARγ interaction, thereby inhibiting lipid metabolism in breast tumor cells. Notably, ST-CY14 significantly suppresses breast cancer growth and bone metastasis in mice. The findings demonstrate the feasibility of exploiting directly Nur77-PPARγ interaction in breast cancer, and generate what to the best knowledge is the first direct inhibitor of the Nur77-PPARγ interaction available for impeding fatty acid uptake and therapeutic development.

The roles of yeast formins and their regulators Bud6 and Bil2 in the pheromone response.

In response to pheromone Saccharomyces cerevisiae extend a mating projection. This process depends on the formation of polarized actin cables which direct secretion to the mating tip and translocate the nucleus for karyogamy. Here, we demonstrate that proper mating projection formation requires the formin Bni1, as well as the actin nucleation promoting activities of Bud6, but not the formin Bnr1. Further, Bni1 is required for pheromone gradient tracking. Our work also reveals unexpected new functions for Bil2 in the pheromone response. Previously we identified Bil2 as a direct inhibitor of Bnr1 during vegetative cell growth. Here, we show that Bil2 has Bnr1-independent functions in spatially focusing Bni1-GFP at mating projection tips, and in vitro Bil2 and its binding partner Bud6 organize Bni1 into clusters that nucleate actin assembly. bil2∆ cells also display entangled Bni1-generated actin cable arrays and defects in secretory vesicle transport and nuclear positioning. At low pheromone concentrations, bil2∆ cells are delayed in establishing a polarity axis, and at high concentrations they prematurely form a second and a third mating projection. Together, these results suggest that Bil2 promotes the proper formation and timing of mating projections by organizing Bni1 and maintaining a persistent axis of polarized growth.

State-of-the-art and upcoming trends in RAS-directed therapies in gastrointestinal malignancies.

Overall, the review underscores the evolving landscape of KRAS-targeted therapy and the potential for these approaches to improve outcomes for patients with gastrointestinal malignancies. It highlights the importance of ongoing research and clinical trials in advancing precision medicine strategies for KRAS-driven cancers. This review provides a comprehensive overview of the RAS signaling pathway and its significance in gastrointestinal malignancies. The introduction of KRAS inhibitor represents a significant advancement in the treatment landscape for KRAS-mutant cancers. In this review, we discuss upcoming trends in KRAS-targeted therapy, including the development of mutant-specific direct KRAS inhibitors like MRTX1133 and pan-RAS inhibitors such as RMC-6236. It also explores indirect RAS inhibitors targeting upstream and downstream components of the RAS pathway. Additionally, the review examines other upcoming strategies like combination therapies, such as CDK4/6 and ERK MAPK inhibitors, as well as adoptive cell therapy and cancer vaccines targeting KRAS-mutant cancers. Targeting RAS has become an important strategy in treating gastrointestinal cancer. These findings in this review underscore the importance of a multidisciplinary approach, integrating advances in molecular profiling, targeted therapy, immunotherapy, and clinical research to optimize treatment strategies for patients with KRAS-mutant gastrointestinal malignancies.

Targeting KRASG12C in Non-Small-Cell Lung Cancer: Current Standards and Developments.

Among the most common molecular alterations detected in non-small-cell lung cancer (NSCLC) are mutations in Kristen Rat Sarcoma viral oncogene homolog (KRAS). KRAS mutant NSCLC is a heterogenous group of diseases, different from other oncogene-driven tumors in terms of biology and response to therapies. Despite efforts to develop drugs aimed at inhibiting KRAS or its signaling pathways, KRAS had remained undruggable for decades. The discovery of a small pocket in the binding switch II region of KRASG12C has revolutionized the treatment of KRASG12C-mutated NSCLC patients. Sotorasib and adagrasib, direct KRASG12C inhibitors, have been approved by the US Food and Drug Administration (FDA) and other regulatory agencies for patients with previously treated KRASG12C-mutated NSCLC, and these advances have become practice changing. However, first-line treatment in KRASG12C-mutated NSCLC does not differ from NSCLC without actionable driver genomic alterations. Treatment with KRASG12C inhibitors is not curative and patients develop progressive disease, so understanding associated mechanisms of drug resistance is key. New KRASG12C inhibitors and several combination therapy strategies, including with immune checkpoint inhibitors, are being studied in clinical trials. The aim of this review is to explore the clinical impact of KRAS, and outline different treatment approaches, focusing on the novel treatment of KRASG12C-mutated NSCLC.