Selective Inhibitor Research Articles

PRMT5 Inhibition Reduces Hyperinflammation in a Murine Model of Secondary Hemophagocytic Lymphohistiocytosis (HLH).

Hemophagocytic lymphohistiocytosis (HLH) is a rare but aggressive and potentially lethal hyperinflammatory syndrome characterized by pathologic immune activation and excessive production of proinflammatory cytokines leading to tissue damage and multisystem organ failure. There is an urgent need for the discovery of novel targets and development of therapeutic strategies to treat this rare but deadly syndrome. Protein Arginine Methyltransferase 5 (PRMT5) mediates T cell-based inflammatory responses, making it a potential actionable target for the treatment of HLH. Using CPG-1826 and anti-IL10R antibody, we induced murine secondary HLH in vivo with a marked expansion of splenic myeloid cell subsets and concurrent reduction of T and NK cell populations. PRMT5 expression was significantly upregulated in splenic T and NK lymphocytes as well as monocytes and dendritic cells in mice with HLH (p<0.05). Treatment with PRT382, a potent and selective PRMT5 inhibitor, significantly reduced physical signs of secondary HLH, including splenomegaly, hepatomegaly and anemia (p<0.0001 in each case), when compared to untreated mice. Inflammatory cytokines known to drive hyperinflammation in HLH, including IFNγ and IL-6 were reduced to healthy levels with PRT382 treatment (p>0.999 for both). PRT382 treatment also reduced the expansion of myeloid cell populations (p<0.0001) in mice with HLH, compared to untreated mice, while restoring T and NK cell numbers (p<0.001 for both). These results identify PRMT5 as a promising target for the management of secondary HLH and justify further exploration in this and other models of hyperinflammation.

WT161, a selective HDAC6 inhibitor, decreases growth, enhances chemosensitivity, promotes apoptosis, and suppresses motility of melanoma cells.

Histone deacetylase 6 (HDAC6) plays a critical role in tumorigenesis and tumor progression, contributing to proliferation, chemoresistance, and cell motility by regulating microtubule architecture. Despite its upregulation in melanoma tissues and cell lines, the specific biological roles of HDAC6 in melanoma are not well understood. This study aims to explore the functional effects and underlying mechanisms of WT161, a selective HDAC6 inhibitor, in melanoma cell lines. Cell proliferation was assessed using both 2D and 3D cell culture systems, including MTT assays, spheroid growth analyses, and colony formation assays. The interaction between WT161 and the chemotherapeutic agents temozolomide (TMZ) or dacarbazine (DTIC) was evaluated using the Chou-Talalay method. Apoptotic cell death was analyzed through flow cytometry, while migration, adhesion, and invasion assays were conducted to evaluate the motility capacities of melanoma cells. Western blot assays quantified α-tubulin acetylation (Lys40), PARP cleavage, and protein levels of β-catenin and E-cadherin. WT161 significantly reduced cell growth in both 2D and 3D cultures, decreased clonogenic capacity, and showed synergistic interactions with TMZ and DTIC. The inhibitor also induced apoptotic cell death and enhanced TMZ-induced apoptosis. Additionally, WT161 reduced cell migration and invasion while increasing cell adhesion. These effects were linked to changes in β-catenin and E-cadherin levels, depending on the specific cell type evaluated. Our study underscores the pivotal role of HDAC6 in melanoma progression, establishing it as a promising therapeutic target. We provide the first comprehensive evidence of WT161's anti-melanoma effects, setting the stage for further research into HDAC6 inhibitors as a potential strategy for melanoma treatment.

Dual inhibition of TYK2 and PD-L1 boosts immune response in triple negative breast cancer.

Recent studies have shown that Janus Kinase inhibitors can enhance the tumor therapeutic effect of immune checkpoint inhibitors. However, it remains to be studied whether TYK2 selective inhibitors can enhance the therapeutic effect of small molecule PD-L1 inhibitors in triple-negative breast cancer (TNBC). We verified the efficacy of the combination of the selective TYK2 inhibitor Deucravacitinib and the small molecule inhibitor of PD-L1, INCB086550, in two TNBC animal models: a syngeneic mouse model (4T1 with humanized PD-L1) and a peripheral blood mononuclear cell (PBMC)-humanized model (MDA-MB-231). Following that, we explored the regulation of immune cell activity in tumors by the combined treatment using flow cytometry. Finally, we validated the expression of genes related to the regulated immune cells through reverse transcription-PCR. Both animal models demonstrated that the addition of a TYK2 inhibitor to a PD-L1 inhibitor significantly enhanced the antitumor capabilities of mice with good safety profiles. The combined therapy significantly elevated the counts of T, B, and natural killer cells while concurrently diminishing myeloid-derived suppressor cells in the syngeneic model. Similarly, in the PBMC-humanized model, this therapy markedly augmented progenitor-like and proliferative precursor-like CD8 T cells, while effectively diminishing exhausted and terminally differentiated CD8 T cell populations. This enhanced antitumor effect is associated with the modulation of antitumor immune-related gene expression by the combined therapy. The combination of TYK2 inhibitors and immune checkpoint inhibitors is a potentially effective strategy for treating TNBC.

Preclinical evidence that fibroblast growth factor receptor pathway inhibition by BGJ398 enhances small cell lung cancer response to chemotherapy.

Small cell lung cancer (SCLC) is a highly aggressive form of lung cancer with limited therapeutic options and poor prognosis. In this study, we explored the therapeutic potential of BGJ398, a selective fibroblast growth factor receptor (FGFR) inhibitor, alone and in combination with standard chemotherapy (cisplatin and paclitaxel) in SCLC. High-throughput screening of kinase inhibitors was performed on three SCLC cell lines (NCI-H446, NCI-H69, and NCI-H182), identifying BGJ398 as one of the most potent and selective inhibitors. BGJ398 demonstrated significant synergy with cisplatin and paclitaxel in vitro, as indicated by combination index values below 1. In vivo, combination treatments significantly inhibited tumor growth and extended survival in SCLC xenograft models compared to monotherapies. Notably, the combination of BGJ398 with cisplatin exhibited the most pronounced tumor suppression and survival benefits. Immunohistochemistry analysis confirmed that BGJ398 effectively inhibited FGFR signaling pathways, reducing levels of phosphorylated FGFR, protein kinase B, signal transducer and activator of transcription 3, and extracellular signal-regulated kinase. These findings suggest that BGJ398, particularly in combination with chemotherapy, holds significant promise as a treatment strategy for SCLC, providing enhanced anti-tumor efficacy and improved survival outcomes.

Rationalizing Predictions of Isoform-Selective Phosphoinositide 3-Kinase Inhibitors Using MolAnchor Analysis.

Explaining the predictions of machine learning models is of critical importance for integrating predictive modeling in drug discovery projects. We have generated a test system for predicting isoform selectivity of phosphoinositide 3-kinase (PI3K) inhibitors and systematically analyzed correct predictions of selective inhibitors using a new methodology termed MolAnchor, which is based on the "anchors" concept from explainable artificial intelligence. The approach is designed to generate chemically intuitive explanations of compound predictions. For nearly all correctly predicted isoform-selective inhibitors, well-defined structural fragments determining the predictions were identified, and in most cases, an individual substructure was responsible for the prediction outcome. For inhibitors with different isoform selectivities, recurrent substructures determining the predictions were distinct. The comparison of newly identified anchor substructures with independent explanations based on calculated feature importance values supported the superior interpretability of MolAnchor explanations. Two highly recurrent substructures determining correct predictions were found to be directly implicated in isoform selectivity of PI3K inhibitors, thus indicating a causal relationship between decisive substructures and selectivity determinants.

Acute selective serotonin-reuptake inhibition elevates basal ventilation, attenuates the rebreathing ventilatory response, independent of cerebral perfusion.

Serotonin (5-HT) is integral to signalling in areas of the brainstem controlling ventilation and is involved in central chemoreception. Selective serotonin reuptake inhibitors (SSRIs), used to effectively increase 5-HT concentrations, are commonly prescribed for depression. The effects of SSRIs on the control of breathing and the potential influence of cerebral blood flow (CBF) have not been directly assessed. We hypothesized that a single SSRI dose in healthy adults would not impact resting ventilation, global CBF, or brainstem blood flow reactivity to CO2, but would steepen the slope of the hypercapnic ventilatory response (HCVR). In 15 young, healthy adults (6 female, 25±5years, 70±10kg, 172±15cm, 24±4kg/cm2), using a placebo-controlled, double-blind, randomized design, we assessed baseline cardiorespiratory and CBF (duplex ultrasound) responses to SSRI (40 mg citalopram), as well as to hyperoxic hypercapnic rebreathing (as an index of central chemoreception). Baseline measures of mean arterial pressure, heart rate, minute ventilation, CBF and the pressures of end-tidal oxygen and carbon dioxide, were all not influenced by SSRI. Likewise, the sum of blood flowing through both vertebral arteries (as an index of brainstem blood flow) during hypercapnia was also unchanged. In contrast, basal ventilation (during rebreathing following hyperventilation and during hyperoxia) was elevated from 9.5±4.1 to 11.5±5.5 L/min (interaction p=0.023); and, counter to our hypothesis, the central chemoreceptor-mediated ventilatory response to CO2 was reduced following SSRI from 7.5±5.3 to 5.1±4.1 L/min/mmHg (interaction p=0.027). The implications of these findings in health and pathology remain to be determined.

Retrospective Study of the Efficacy of Biofeedback Therapy for Pediatric Persistent Posttraumatic Headache.

Posttraumatic headache is common in pediatrics. Studies have examined treatment of postconcussion symptoms, but few target posttraumatic headache. Biofeedback therapy has been studied in children and teens with primary headaches, but not posttraumatic headache. Our goal was to examine the changes in posttraumatic headache associated with biofeedback therapy in pediatric patients. This retrospective study included 74 children aged 10-18 years who received biofeedback therapy for posttraumatic headache. "Positive response" to biofeedback therapy was defined as ≥50% reduction in headache days per week, or 3-point drop in pain rating between the first and last biofeedback therapy visits. Patient characteristics were analyzed using logistic regression to identify factors associated with response. In our cohort, 42% of all patients with posttraumatic headache had a positive response to biofeedback therapy. Thirty-six percent experienced ≥50% decrease in headache frequency, 13% had a ≥3-point decrease in headache severity and 8% reported both changes. For those with daily headaches, 36% had a positive response to biofeedback therapy. School absences, selective serotonin reuptake inhibitor or prescription preventive medication use were associated with nonresponse. Biofeedback therapy is a reasonable treatment to consider to manage pediatric posttraumatic headache because more than 40% of our cohort had a beneficial response and biofeedback therapy has few adverse effects.

Induction of DNA damage and growth arrest by citalopram in breast cancer cells mediated via activation of Gadd45a and apoptotic genes.

Breast cancer patients experience more severe emotional distress and depression compared to those with other cancers. Selective serotonin reuptake inhibitors (SSRIs), like citalopram, are commonly used to treat depression. However, the link between SSRI use and breast cancer progression is debated. This study examined the cytotoxic effects of citalopram on triple-negative (MDA-MB231) and ER-positive (MCF-7) breast cancer cells. Results showed a significant decrease in cell viability in both cell lines following citalopram treatment. Interestingly, flow cytometry analysis revealed increased apoptotic cells and induction of cell cycle arrest upon treatment of the cells with citalopram. MCF-7 cells were arrested in the sub-G0-G1 phase, while MDA-MB231 cells accumulated in the S phase. Gene expression analysis demonstrated increased Bax expression and decreased Bcl2 levels. Moreover, cytochrome c and NF-κB were upregulated upon treatment with citalopram. Furthermore, transmission electron microscopy (TEM) analysis of treated cells showed apoptotic morphological changes including shrunken nuclei, membrane blebbing, and chromatin condensation with prominent appearance of autophagosomes and autolysosomes. Additionally, GADD45a and p21, involved in growth arrest and DNA damage, were significantly upregulated. In conclusion, citalopram's ability to induce apoptosis and alter cell cycle suggests its potential in breast cancer treatment.

Selective deficiency of mitochondrial respiratory complex I subunits Ndufs4/6 causes tumor immunogenicity.

Cancer cells frequently rewire their metabolism to support proliferation and evade immune surveillance, but little is known about metabolic targets that could increase immune surveillance. Here we show a specific means of mitochondrial respiratory complex I (CI) inhibition that improves tumor immunogenicity and sensitivity to immune checkpoint blockade (ICB). Targeted genetic deletion of either Ndufs4 or Ndufs6, but not other CI subunits, induces an immune-dependent growth attenuation in melanoma and breast cancer models. We show that deletion of Ndufs4 induces expression of the major histocompatibility complex (MHC) class I co-activator Nlrc5 and antigen presentation machinery components, most notably H2-K1. This induction of MHC-related genes is driven by a pyruvate dehydrogenase-dependent accumulation of mitochondrial acetyl-CoA, which leads to an increase in histone H3K27 acetylation within the Nlrc5 and H2-K1 promoters. Taken together, this work shows that selective CI inhibition restricts tumor growth and that specific targeting of Ndufs4 or Ndufs6 increases T cell surveillance and ICB responsiveness.

Coffee Pulp from Azores: A Novel Phytochemical-Rich Food with Potential Anti-Diabetic Properties

Coffee pulp, a by-product of wet coffee processing, shows significant potential in the food and health domains, but its real applications remain underexplored. This work investigated the chemical composition and bioactive properties of coffee pulp from São Miguel Island (Azores, Portugal). The studied coffee pulp exhibited high fiber content (52% dw), mostly insoluble; notable mineral levels (10.6%), mainly K, Ca, and Mg; and 6% dw of total amino acids, with hydroxyproline, aspartic acid, glutamic acid, and leucine in higher amounts. Despite containing low fat (1.6% dw), mainly saturated, it also showed considerable amounts of polyunsaturated fatty acids with a favorable n6/n3 ratio (1.40) and vitamin E (α-, β-, and γ-tocopherols). Its antioxidant capacity can be partially explained by the chlorogenic acid content (9.2 mg/g dw), and caffeine (0.98%) was present in similar amounts to those observed in some arabica coffee beans. A decrease in glucose uptake in Caco-2 cells was found, but not in fructose, suggesting selective inhibition of SGLT1 and potential antidiabetic effects. These results show that Azorean coffee pulp has potential as a sustainable and bioactive ingredient for incorporation into functional foods or dietary supplements.

Multiple Kinase Small Molecule Inhibitor Tinengotinib (TT-00420) Alone or With Chemotherapy Inhibit the Growth of SCLC.

There is an urgent need to develop new targeted treatment agents for small cell lung cancer (SCLC). Tinengotinib (TT-00420) is a novel, multi-targeted, and spectrally selective small-molecule kinase inhibitor that has shown significant inhibitory effects on certain solid tumors in preclinical studies. However, its role and mechanism of action in SCLC remain unclear. In this study, we demonstrated that tinengotinib effectively inhibited SCLC cell proliferation, especially highly expressing NeuroD1 (SCLC-N), in the SCLC cell line-derived xenograft (CDX) model and the malignant pleural effusion cell model of patients with SCLC. When combined with etoposide/cisplatin, it synergistically inhibited SCLC growth. Tinengotinib regulates proliferation, apoptosis, migration, cell cycle and angiogenesis in SCLC cells. Mechanistic studies revealed that c-Myc expression may be a key factor influencing the effect of tinengotinib in SCLC-N. This study provides reliable preclinical data and a new direction for tinengotinib as a promising therapy for SCLC, either alone or in combination with chemotherapy.

A Simple and Efficient Stereoselective Synthesis of a 2,3-Difluorosialic acid-based influenza virus neuraminidase inhibitor.

3-Fluoroneuraminosyl fluorides are invaluable probes for studying the catalytic mechanism of sialidases (neuraminidases), and as sialidase inhibitors. Significantly, when a C-3 equatorial fluorine is installed on a C-4 functionalised N-acylneuraminic acid (Neu)-based template, the compounds are potent and selective inhibitors of both influenza and parainfluenza sialidases, and of virus replication. Typically, the reported syntheses of 3-fluoroneuraminosyl fluorides involve either an enzymatic or a chemical synthesis that have uncontrolled stereoselectivity in the introduction of fluorine at C-3 of Neu and consequently yield a mixture of C-3 ax and C-3 eq fluoro derivatives. We now report a simple approach for the exquisitely stereo-controlled introduction of the C-3 equatorial fluorine on Neu by incorporation of steric bulk at C-4. Through this method, we have elaborated a novel synthetic route that exclusively produces the potent anti-influenza drug candidate; 2,3-difluoro-zanamivir analogue with C-3 eq fluoride.

A physiologically-based quantitative systems pharmacology model for mechanistic understanding of the response to alogliptin and its application in patients with renal impairment.

Alogliptin is a highly selective inhibitor of dipeptidyl peptidase-4 and primarily excreted as unchanged drug in the urine, and differences in clinical outcomes in renal impairment patients increase the risk of serious adverse reactions. In this study, we developed a comprehensive physiologically-based quantitative systematic pharmacology model of the alogliptin-glucose control system to predict plasma exposure and use glucose as a clinical endpoint to prospectively understand its therapeutic outcomes with varying renal function. Our model incorporates a PBPK model for alogliptin, DPP-4 activity described by receptor occupancy theory, and the crosstalk and feedback loops for GLP-1-GIP-glucagon, insulin, and glucose. Based on the optimization of renal function-dependent parameters, the model was extrapolated to different stages renal impairment patients. Ultimately our model adequately describes the pharmacokinetics of alogliptin, the progression of DPP-4 inhibition over time and the dynamics of the glucose control system components. The extrapolation results endorse the dose adjustment regimen of 12.5mg once daily for moderate patients and 6.25mg once daily for severe and ESRD patients, while providing additional reflections and insights. In clinical practice, our model could provide additional information on the in vivo fate of DPP4 inhibitors and key regulators of the glucose control system.

Resveratrol-Based Carbamates as Selective Butyrylcholinesterase Inhibitors: Design, Synthesis, Computational Study and Biometal Complexation Capability

Considering our previous experience in the design of new cholinesterase inhibitors, especially resveratrol analogs, in this research, the basic stilbene skeleton was used as a structural unit for new carbamates designed as potentially highly selective butyrylcholinesterase (BChE) inhibitors with excellent absorption, distribution, metabolism, excretion and toxicity ADMET properties. The inhibitory activity of newly prepared carbamates 1–13 was tested toward the enzymes acetylcholinesterase (AChE) and BChE. In the tested group of compounds, the leading inhibitors were 1 and 7, which achieved excellent selective inhibitory activity for BChE with IC50 values of 0.12 ± 0.09 μM and 0.38 ± 0.01 μM, respectively. Both were much more active than the standard inhibitor galantamine against BChE. Molecular docking of the most promising inhibitor candidates, compounds 1 and 7, revealed that stabilizing interactions between the active site residues of BChE and the ligands involve π-stacking, alkyl-π interactions, and, when the carbamate orientation allows, H-bond formation. MD analysis confirmed the stability of the obtained complexes. Some bioactive resveratrol-based carbamates displayed complex-forming capabilities with Fe3+ ions as metal centers. Spectrophotometric investigation indicated that they coordinate one or two metal ions, which is in accordance with their chemical structure, offering two binding sites: an amine and a carboxylic group in the carbamate moiety. Based on the obtained in silico, experimental and computational results on biological activity in the present work, new carbamates 1 and 7 represent potential selective BChE inhibitors as new therapeutics for neurological disorders.

Small molecule inhibits KCNQ channels with a non-blocking mechanism.

Voltage-gated ion channels (VGICs) are crucial targets for neuropsychiatric therapeutics owing to their role in controlling neuronal excitability and the established link between their dysfunction and neurological diseases, highlighting the importance of identifying modulators with distinct mechanisms. Here we report two small-molecule modulators with the same chemical scaffold, Ebio2 and Ebio3, targeting a potassium channel KCNQ2, with opposite effects: Ebio2 acts as a potent activator, whereas Ebio3 serves as a potent and selective inhibitor. Guided by cryogenic electron microscopy, patch-clamp recordings and molecular dynamics simulations, we reveal that Ebio3 attaches to the outside of the inner gate, employing a unique non-blocking inhibitory mechanism that directly squeezes the S6 pore helix to inactivate the KCNQ2 channel. Ebio3 also showed efficacy in inhibiting currents of KCNQ2 pathogenic gain-of-function mutations, presenting an avenue for VGIC-targeted therapies. Overall, these findings contribute to the understanding of KCNQ2 inhibition and provide insights into developing selective, non-blocking VGIC inhibitors.

Case report: Selpercatinib in the treatment of RET fusion-positive advanced lung adenocarcinoma: a challenging clinical case

BackgroundRearranged during transfection (RET) fusions represent a distinct molecular subset of non-small cell lung cancer (NSCLC) with targeted therapeutic potential. Selpercatinib, a highly selective RET inhibitor, has demonstrated efficacy in various solid tumors harboring RET alterations. Here, we present a case highlighting the use and clinical outcomes of selpercatinib in a patient diagnosed with advanced lung adenocarcinoma harboring a RET fusion.Case presentationA 59-year-old woman with a history of stage IV lung adenocarcinoma harboring a KIF5B-RET fusion presented with disease progression following first-line chemo-immunotherapy. Selpercatinib was initiated as a targeted therapy, leading to a notable radiographic response and clinical improvement. The patient experienced a significant reduction in tumor burden and reported improved symptom control, with no significant adverse effects during the 21-month follow-up period.ConclusionsThis case highlights the efficacy and tolerability of selpercatinib in treating advanced lung adenocarcinoma with a RET fusion. The observed clinical response supports the early use of selpercatinib as a targeted therapy for RET fusion-positive NSCLC, including in patients with compromised general and respiratory conditions, especially in cases refractory to conventional treatments. Long-term follow-up studies are warranted to validate these findings and assess the durability of responses.

Drug-Induced Myoclonus: A Systematic Review

Background and Objectives: Myoclonus is already associated with a wide variety of drugs and systemic conditions. As new components are discovered, more drugs are suspected of causing this disabling abnormal involuntary movement. This systematic review aims to assess the medications associated with drug-induced myoclonus (DIM). Materials and Methods: Two reviewers assessed the PubMed database using the search term “myoclonus”, without language restriction, for articles published between 1955 and 2024. The medications found were divided into classes and sub-classes, and the subclasses were graded according to their level of evidence. Results: From 12,097 results, 1115 were found to be DIM. The subclasses of medications with level A evidence were intravenous anesthetics (etomidate), cephalosporins (ceftazidime, cefepime), fluoroquinolones (ciprofloxacin), selective serotonin reuptake inhibitors (citalopram, escitalopram, paroxetine, sertraline), tricyclic antidepressant (amitriptyline), glutamate antagonist (amantadine), atypical antipsychotics (clozapine, quetiapine), antiseizure medications (carbamazepine, oxcarbazepine, phenytoin, gabapentin, pregabalin, valproate), pure opioid agonist (fentanyl, morphine), bismuth salts, and mood stabilizers (lithium). The single medication with the highest number of reports was etomidate. Drug-induced asterixis is associated with a specific list of medications. The neurotransmitters likely involved in DIM are serotonin, dopamine, gamma-aminobutyric acid (GABA), and glutamate. Conclusions: DIM may be reversible with management that can include drug discontinuation, dose adjustment, and the prescription of a medication used to treat idiopathic myoclonus. Based on the main clinical constellation of symptoms and pathophysiological mechanisms found in this study, DIM can be categorized into three types: type 1 (serotonin syndrome), type 2 (non-serotonin syndrome), and type 3 (unknown).

Selective Gamma-Secretase Inhibition by CHF5074 Attenuates Inflammation and Neovascularization in a Murine Model of Choroidal Neovascularization

Purpose Chronic inflammation plays an important role in the pathogenesis of choroidal neovascularization (CNV). This study aimed to investigate the effect of the CHF5074, a γ-secretase inhibitor, on angiogenesis in a laser-induced CNV model and elucidate its possible molecular mechanism. Methods Male C57/BL6J mice aged between 6 to 8 weeks were employed to set up a laser-induced model of CNV. Then, CHF5074 was injected intraperitoneally on the day after laser modeling, as well as on the second, third, and fourth days. Immunofluorescence staining was used to evaluate the retinal and choroidal complex. The markers used were CD31 for neovascularization and IBA1 for microglia staining in ocular tissue slices. Fundus fluorescein angiography on days 3d, 7d, and 14d analyzed neovascularization and leakage areas. Inflammatory indicators were examined by Western blot (WB) and enzyme-linked immunosorbent assay (ELISA). High-throughput whole-tissue sequencing of retinal choroids identified relevant cell pathways. Key regulatory factors modulated by CHF5074 were identified via WB. Co-culture of BV2 cells and human umbilical vein endothelial cells (HUVEC) were used to explore the function of CHF5074 on the inhibition of tube formation. Results CHF5074 significantly decreased CD31 expression in the choroid on 3d, 7d, and 14d post-laser modeling (p < 0.05) and decreased both neovascularization and leakage areas (p < 0.05). Additionally, CHF5074 significantly lowered TNF-α, IL-10, and IL-1β expression levels in the choroid (p < 0.05), as demonstrated by WB analysis and ELISA. High-throughput whole-tissue sequencing identified P38-MAPK, JNK, and Wnt signaling pathways associated with neovascularization. CHF5074 decreased P38 protein phosphorylation (p < 0.05) as confirmed by WB analysis. CHF5074 inhibited the tube formation of HUVECs co-cultured with LPS and ATP-treated BV2 cells. Conclusion CHF5074 significantly suppresses angiogenesis in laser-induced choroidal neovascularization models, suggesting its potential as a novel agent for preventing and treating CNV.

Ferroptosis Inducers Erastin and RSL3 Enhance Adriamycin and Topotecan Sensitivity in ABCB1/ABCG2-Expressing Tumor Cells

Acquired resistance to chemotherapeutic drugs is the primary cause of treatment failure in the clinic. While multiple factors contribute to this resistance, increased expression of ABC transporters—such as P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and multidrug resistance proteins—play significant roles in the development of resistance to various chemotherapeutics. We found that Erastin, a ferroptosis inducer, was significantly cytotoxic to NCI/ADR-RES, a P-gp-expressing human ovarian cancer cell line. Here, we examined the effects of both Erastin and RSL3 (Ras-Selected Ligand 3) on reversing Adriamycin resistance in these cell lines. Our results show that Erastin significantly enhanced Adriamycin uptake in NCI/ADR-RES cells without affecting sensitive cells. Furthermore, we observed that Erastin enhanced Adriamycin cytotoxicity in a time-dependent manner. The selective iNOS inhibitor, 1400W, reduced both uptake and cytotoxicity of Adriamycin in P-gp-expressing NCI/ADR-RES cells only. These findings were also confirmed in a BCRP-expressing human breast cancer cell line (MCF-7/MXR), which was selected for resistance to Mitoxantrone. Both Erastin and RSL3 were found to be cytotoxic to MCF-7/MXR cells. Erastin significantly enhanced the uptake of Hoechst dye, a well-characterized BCRP substrate, sensitizing MCF-7/MXR cells to Topotecan. The effect of Erastin was inhibited by 1400W, indicating that iNOS is involved in Erastin-mediated enhancement of Topotecan cytotoxicity. RSL3 also significantly increased Topotecan cytotoxicity. Our findings—demonstrating increased cytotoxicity of Adriamycin and Topotecan in P-gp- and BCRP-expressing cells—suggest that ferroptosis inducers may be highly valuable in combination with other chemotherapeutics to manage patients’ cancer burden in the clinical setting.

The Selective WEE1 Inhibitor Azenosertib Shows Synergistic Antitumor Activity with KRASG12C Inhibitors in Preclinical Models.

KRAS is a potent oncogenic driver which results in downstream hyperactivation of MAPK signaling, while simultaneously increasing replication stress (RS) and accumulation of DNA damage. KRASG12C mutations are common and targetable alterations. Therapeutic inhibition of KRASG12C and eventual resistance to these inhibitors are also known to drive RS and DNA damage through adaptive mechanisms that maintain addiction to high MAPK signaling. High levels of RS result in a stronger reliance on cell cycle checkpoints, thereby introducing a vulnerability to inhibition of cell cycle checkpoint regulators such as the WEE1 kinase. This provides rationale for combining azenosertib, a novel, selective, and orally bioavailable WEE1 inhibitor, with KRASG12C inhibitors. In vitro combination of azenosertib with multiple KRASG12C inhibitors demonstrated synergistic cell growth inhibition across a panel of KRASG12C cell lines in both 2D and 3D assays. In vivo studies demonstrated azenosertib exhibited significant monotherapy activity as well as synergistic tumor growth inhibition (TGI) when combined with KRASG12C inhibitors, including tumor regression in CDX models of NSCLC, CRC, and PDAC. Importantly, KRASG12C inhibitor-resistant CDX and PDX models demonstrated synergistic TGI in combination arms. Finally, analysis of biomarkers from in vitro and in vivo tumor samples displayed increases in protein markers of RS, DNA damage, and apoptosis after combination treatment. Taken together, our results suggest that the combination of azenosertib with KRASG12C inhibitors enhances tumor growth inhibition over single agent therapy and may be an effective treatment strategy for patients with KRASG12C tumors.