The effect of selinexor on prostaglandin synthesis in virus-positive Merkel cell carcinoma cell lines.

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine skin cancer with high rates of metastasis and mortality. In vitro studies suggest that selinexor (KPT-330), an inhibitor of exportin 1, may be a targeted therapeutic option for MCC. This selective inhibitor prevents the transport of oncogenic mRNA out of the nucleus. Of note, 80% of MCC tumors are integrated with Merkel cell polyomavirus (MCPyV), and virally encoded tumor-antigens, small T (sT) and large T (LT) mRNAs may require an exportin transporter to relocate to the cytoplasm and modulate host tumor-suppressing pathways. To explore selinexor as a targeted therapy for MCC, we examine its ability to inhibit LT and sT antigen expression in vitro and its impact on the prostaglandin synthesis pathway. Protein expression was determined through immunoblotting and quantified by densitometric analysis. Statistical significance was determined with t-test. Treatment of MCPyV-infected cell lines with selinexor resulted in a significant dose-dependent downregulation of key mediators of the prostaglandin synthesis pathway. Given the role of prostaglandin synthesis pathway in MCC, our findings suggest that selinexor, alone or in combination with immunotherapy, could be a promising treatment for MCPyV-infected MCC patients who are resistant to chemotherapy and immunotherapy.

Glucosyltriazole amphiphile treatment attenuates breast cancer by modulating the AMPK signaling.

Breast cancer is the second most frequent cancer among women. Out of various subtypes, triple-negative breast cancers (TNBCs) account for 15% of breast cancers and exhibit more aggressive characteristics as well as a worse prognosis due to their proclivity for metastatic progression and limited therapeutic strategies. It has been demonstrated that AMP-activated protein kinase (AMPK) has context-specific protumorigenic implications in breast cancer cells. A set of glucosyltriazole amphiphiles, consisting of acetylated (9a-h) and unmodified sugar hydroxyl groups (10a-h), were synthesized and subjected to in vitro biological evaluation. Among them, 9h exhibited significant anticancer activity against MDA-MB-231, MCF-7, and 4T1 cell lines with IC50 values of 12.5, 15, and 12.55 µM, respectively. Further, compound 9h was evaluated for apoptosis and cell cycle analysis in in vitro models (using breast cancer cells) and antitumour activity in an in vivo model (orthotopic mouse model using 4T1 cells). Annexin-V assay results revealed that treatment with 9h caused 34% and 28% cell death at a concentration of 15 or 7.5 µM, respectively, while cell cycle analysis demonstrated that 9h arrested the cells at the G2/M or G1 phase in MCF-7, MDA-MB-231 and 4T1 cells, respectively. Further, in vivo, investigation showed that compound 9h exhibited equipotent as doxorubicin at 7.5 mg/kg, and superior efficacy than doxorubicin at 15 mg/kg. The mechanistic approach revealed that 9h showed potent anticancer activity in an in vivo orthotopic model (4T1 cells) partly by suppressing the AMPK activation. Therefore, modulating the AMPK activation could be a probable approach for targeting breast cancer and mitigating cancer progression.

Exploring of N-phthalimide-linked 1,2,3-triazole analogues with promising -anti-SARS-CoV-2 activity: synthesis, biological screening, and molecular modelling studies.

In this study, a library of phthalimide Schiff base linked to 1,4-disubstituted-1,2,3-triazoles was designed, synthesised, and characterised by different spectral analyses. All analogues have been introduced for in vitro assay of their antiviral activity against COVID-19 virus using Vero cell as incubator with different concentrations. The data revealed most of these derivatives showed potent cellular anti-COVID-19 activity and prevent viral growth by more than 90% at two different concentrations with no or weak cytotoxic effect on Vero cells. Furthermore, in vitro assay was done against this enzyme for all analogues and the results showed two of them have IC50 data by 90 µM inhibitory activity. An extensive molecular docking simulation was run to analyse their antiviral mechanism that found the proper non-covalent interaction within the Mpro protease enzyme. Finally, we profiled two reversible inhibitors, COOH and F substituted analogues that might be promising drug candidates for further development have been discovered.

New sulfonamide-based glycosides incorporated 1,2,3-triazole as cytotoxic agents through VEGFR-2 and carbonic anhydrase inhibitory activity.

New sulfonamide-triazole-glycoside hybrids derivatives were designed, synthesised, and investigated for anticancer efficacy. The target glycosides' cytotoxic activity was studied with a panel of human cancer cell lines. Sulfonamide-based derivatives, 4, 7 and 9 exhibited promising activity against HepG-2 and MCF-7 (IC50 = 8.39-16.90 µM against HepG-2 and 19.57-21.15 µM against MCF-7) comparing with doxorubicin (IC50 = 13.76 ± 0.45, 17.44 ± 0.46 µM against HepG-2 and MCF-7, rescpectively). To detect the probable action mechanism, the inhibitory activity of these targets was studied against VEGFR-2, carbonic anhydrase isoforms hCA IX and hCA XII. Compoumds 7 and 9 gave favorable potency (IC50 = 1.33, 0.38 µM against VEGFR-2, 66, 40 nM against hCA IX and 7.6, 3.2 nM against hCA XII, respectively), comparing with sorafenib and SLC-0111 (IC50 = 0.43 µM, 53 and 4.8 nM, respectively). Moreover, the docking simulation was assessed to supply better rationalization and gain insight into the binding affinity between the promising derivatives and their targeted enzymes that was used for further modification in the anticancer field.

Adenosine A2A Receptor Blockade Provides More Effective Benefits at the Onset Rather than after Overt Neurodegeneration in a Rat Model of Parkinson's Disease.

Adenosine A2A receptor (A2AR) antagonists are the leading nondopaminergic therapy to manage Parkinson's disease (PD) since they afford both motor benefits and neuroprotection. PD begins with a synaptic dysfunction and damage in the striatum evolving to an overt neuronal damage of dopaminergic neurons in the substantia nigra. We tested if A2AR antagonists are equally effective in controlling these two degenerative processes. We used a slow intracerebroventricular infusion of the toxin MPP+ in male rats for 15 days, which caused an initial loss of synaptic markers in the striatum within 10 days, followed by a neuronal loss in the substantia nigra within 30 days. Interestingly, the initial loss of striatal nerve terminals involved a loss of both dopaminergic and glutamatergic synaptic markers, while GABAergic markers were preserved. The daily administration of the A2AR antagonist SCH58261 (0.1 mg/kg, i.p.) in the first 10 days after MPP+ infusion markedly attenuated both the initial loss of striatal synaptic markers and the subsequent loss of nigra dopaminergic neurons. Strikingly, the administration of SCH58261 (0.1 mg/kg, i.p. for 10 days) starting 20 days after MPP+ infusion was less efficacious to attenuate the loss of nigra dopaminergic neurons. This prominent A2AR-mediated control of synaptotoxicity was directly confirmed by showing that the MPTP-induced dysfunction (MTT assay) and damage (lactate dehydrogenase release assay) of striatal synaptosomes were prevented by 50 nM SCH58261. This suggests that A2AR antagonists may be more effective to counteract the onset rather than the evolution of PD pathology.

Synthesis, In Silico and Kinetics Evaluation of N-(ß-d-glucopyranosyl)-2-arylimidazole-4(5)-carboxamides and N-(ß-d-glucopyranosyl)-4(5)-arylimidazole-2-carboxamides as Glycogen Phosphorylase Inhibitors.

Recently studied N-(ß-d-glucopyranosyl)-3-aryl-1,2,4-triazole-5-carboxamides have proven to be low micromolar inhibitors of glycogen phosphorylase (GP), a validated target for the treatment of type 2 diabetes mellitus. Since in other settings, the bioisosteric replacement of the 1,2,4-triazole moiety with imidazole resulted in significantly more efficient GP inhibitors, in silico calculations using Glide molecular docking along with unbound state DFT calculations were performed on N-(ß-d-glucopyranosyl)-arylimidazole-carboxamides, revealing their potential for strong GP inhibition. The syntheses of the target compounds involved the formation of an amide bond between per-O-acetylated ß-d-glucopyranosylamine and the corresponding arylimidazole-carboxylic acids. Kinetics experiments on rabbit muscle GPb revealed low micromolar inhibitors, with the best inhibition constants (Kis) of ~3-4 µM obtained for 1- and 2-naphthyl-substituted N-(ß-d-glucopyranosyl)-imidazolecarboxamides, 2b-c. The predicted protein-ligand interactions responsible for the observed potencies are discussed and will facilitate the structure-based design of other inhibitors targeting this important therapeutic target. Meanwhile, the importance of the careful consideration of ligand tautomeric states in binding calculations is highlighted, with the usefulness of DFT calculations in this regard proposed.

A first-in-class inhibitor of HSP110 to potentiate XPO1-targeted therapy in primary mediastinal B-cell lymphoma and classical Hodgkin lymphoma.

BACKGROUND: Primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (cHL) are distinct hematological malignancies of B-cell origin that share many biological, molecular, and clinical characteristics. In particular, the JAK/STAT signaling pathway is a driver of tumor development due to multiple recurrent mutations, particularly in STAT6. Furthermore, the XPO1 gene that encodes exportin 1 (XPO1) shows a frequent point mutation (E571K) resulting in an altered export of hundreds of cargo proteins, which may impact the success of future therapies in PMBL and cHL. Therefore, targeted therapies have been envisioned for these signaling pathways and mutations. METHODS: To identify novel molecular targets that could overcome the treatment resistance that occurs in PMBL and cHL patients, we have explored the efficacy of a first-in-class HSP110 inhibitor (iHSP110-33) alone and in combination with selinexor, a XPO1 specific inhibitor, both in vitro and in vivo. RESULTS: We show that iHSP110-33 decreased the survival of several PMBL and cHL cell lines and the size of tumor xenografts. We demonstrate that HSP110 is a cargo of XPO1wt as well as of XPO1E571K. Using immunoprecipitation, proximity ligation, thermophoresis and kinase assays, we showed that HSP110 directly interacts with STAT6 and favors its phosphorylation. The combination of iHSP110-33 and selinexor induces a synergistic reduction of STAT6 phosphorylation and of lymphoma cell growth in vitro and in vivo. In biopsies from PMBL patients, we show a correlation between HSP110 and STAT6 phosphorylation levels. CONCLUSIONS: These findings suggest that HSP110 could be proposed as a novel target in PMBL and cHL therapy.

Design, Synthesis, and 3D-QASR of 2-Ar-1,2,3-triazole Derivatives Containing Hydrazide as Potential Fungicides.

A series of novel 2-Ar-1,2,3-triazole derivatives were designed and synthesized based on our previously discovered active compound 6d against Rhizoctonia solani. Most of these compounds exhibited good antifungal activity against R. solani at a concentration of 25 µg/mL. Based on the results of biological activity, we established a three-dimensional quantitative structure-activity relationship (3D-QSAR) model that guided the synthesis of compound 7y. Compound 7y exhibited superior activity against R. solani (EC50 = 0.47 µg/mL) compared to the positive controls hymexazol (EC50 = 12.80 µg/mL) and tebuconazole (EC50 = 0.87 µg/mL). Furthermore, compound 7y demonstrated better protective activity than the aforementioned two commercial fungicides in both detached leaf assays and greenhouse experiments, achieving 56.21% and 65.75% protective efficacy, respectively, at a concentration of 100 µg/mL. The ergosterol content was determined and molecular docking was performed to explore the mechanism of these active molecules. DFT calculation and MEP analysis were performed to illustrate the results of this study. These results suggest that compound 7y could serve as a novel 2-Ar-1,2,3-triazole lead compound for controlling R. solani.

A novel approach to exploit Small-Molecule glucagon-like Peptide-1 receptor agonists with high potency.

Small-molecule glucagon-like peptide-1 receptor (GLP-1R) agonists are recognized as promising therapeutics for type 2 diabetes mellitus (T2DM) and obesity. Danuglipron, an investigational small-molecule agonist, has demonstrated high efficacy in clinical trials. However, further development of danuglipron is challenged by a high rate of gastrointestinal adverse events. While these effects may be target-related, it is plausible that the carboxylic acid group present in danuglipron may also play a role in these outcomes by affecting the pharmacokinetic properties and dosing regimen of danuglipron, as well as by exerting direct gastrointestinal irritation. Therefore, this study aims to replace the problematic carboxylic acid group by exploring the internal binding cavity of danuglipron bound to GLP-1R using a water molecule displacement strategy. A series of novel triazole-containing compounds have been designed and synthesized during the structure-activity relationship (SAR) study. These efforts resulted in the discovery of compound 2j with high potency (EC50 = 0.065 nM). Moreover, docking simulations revealed that compound 2j directly interacts with the residue Glu387 within the internal cavity of GLP-1R, effectively displacing the structural water previously bound to Glu387. Subsequent in vitro and in vivo experiments demonstrated that compound 2j had comparable efficacy to danuglipron in enhancing insulin secretion and improving glycemic control. Collectively, this study offers a practicable approach for the discovery of novel small-molecule GLP-1R agonists based on danuglipron, and compound 2j may serve as a lead compound to further exploit the unoccupied internal cavity of danuglipron's binding pocket.

Beyond oncology: Selinexor's journey into anti-inflammatory treatment and long-term management.

Selinexor, a selective inhibitor of nuclear export (SINE), is gaining recognition beyond oncology for its potential in anti-inflammatory therapy. This review elucidates Selinexor's dual action, highlighting its anti-tumor efficacy in various cancers including hematologic malignancies and solid tumors, and its promising anti-inflammatory effects. In cancer treatment, Selinexor has demonstrated benefits as monotherapy and in combination with other therapeutics, particularly in drug-resistant cases. Its role in enhancing the effectiveness of bone marrow transplants has also been noted. Importantly, the drug's impact on key inflammatory pathways provides a new avenue for the management of conditions like sepsis, viral infections including COVID-19, and chronic inflammatory diseases such as Duchenne Muscular Dystrophy and Parkinson's Disease. The review emphasizes the criticality of managing Selinexor's side effects through diligent dose optimization and patient monitoring. Given the complexities of its broader applications, extensive research is called upon to validate Selinexor's long-term safety and effectiveness, with a keen focus on its integration into clinical practice for a diverse spectrum of disorders.

First detection of triazole-resistant aspergillus fumigatus harbouring the TR34/L98H Cyp51A mutation in Burkina Faso.

BACKGROUND: Triazole-resistant Aspergillus fumigatus (TRAF) isolates are a growing public health problem with worldwide distribution. Epidemiological data on TRAF is limited in Africa, particularly in West Africa. OBJECTIVES: This study aimed to screen for the environmental presence of TRAF isolates in the indoor air of two hospitals in Burkina Faso. MATERIALS AND METHODS: Air samples were collected in wards housing patients at risk for invasive aspergillosis, namely infectious diseases ward, internal medicine ward, nephrology ward, pulmonology ward, medical emergency ward and paediatric ward. Sabouraud Dextrose Agar supplemented with triazoles was used to screen the suspected TRAF isolates and EUCAST method to confirm the resistance of suspected isolates. Sequencing of cyp51A gene was used to identify the resistance mechanism of confirmed TRAF isolates. RESULTS: Of the 198 samples collected and analysed, 67 showed growth of A. fumigatus isolates. The prevalence of TRAF isolates was 3.23% (4/124). One TRAF isolate exhibited a pan-triazole resistance. Sequencing of cyp51A gene identified the TR34/L98H mutation for this pan-triazole resistant isolate. This study showed for the first time the circulation of the pan-azole resistant isolate harbouring the TR34/L98H mutation in Burkina Faso. CONCLUSIONS: These findings emphasise the need to map these TRAF isolates in all parts of Burkina Faso and to establish local and national continuous surveillance of environmental and clinical TRAF isolates in this country.

Design of Triazolium-Grafted Peptidomimetic Macrocycles with Facial Amphipathicity to Target Pathogenic Bacteria.

Access to 1,2,3-triazolium-grafted peptoid macrocycles was developed by macrocyclization and multivalent postmodification of linear peptoid oligomers carrying an alternance of benzylic and propargyl groups as side chains. X-ray analysis and NMR studies revealed a conformational preference for constrained hairpin-shaped structures leading to the facial amphipathic character of these macrocycles. A preliminary evaluation showed the antimicrobial activities of these new cationic amphipathic architectures.

Identification and fungicides sensitivity evaluation of the causal agent of cobweb disease on Lyophyllum decastes in China.

BACKGROUND: Cobweb disease is a fungal disease that commonly affects the cultivation and production of edible mushrooms, leading to serious yield and economic losses. It is considered a major fungal disease in the realm of edible mushrooms. The symptoms of cobweb disease were found during the cultivation of Lyophyllum decastes. This study aimed to identify the causative pathogen of cobweb disease and evaluate effective fungicides, providing valuable insights for field control and management of L. decastes cobweb disease. RESULTS: The causal agent of cobweb disease was isolated from samples infected and identified as Cladobotryum mycophilum based on morphological and cultural characteristics, as well as multi-locus phylogeny analysis (ITS, RPB1, RPB2, and TEF1-α). Pathogenicity tests further confirmed C. mycophilum as the responsible pathogen for this condition. Among the selected fungicides, Prochloraz-manganese chloride complex, Trifloxystrobin, tebuconazole, and Difenoconazole exhibited significant inhibitory effects on the pathogen's mycelium, with EC50 values of 0.076 µg/mL, 0.173 µg/mL, and 0.364 µg/mL, respectively. These fungicides can serve as references for future field control of cobweb disease in L. decastes. CONCLUSION: This study is the first report of C. mycophilum as the causing agent of cobweb disease in L. decastes in China. Notably, Prochloraz-manganese chloride complex demonstrated the strongest inhibitory efficacy against C. mycophilum.

Crucial Involvement of Heme Biosynthesis in Vegetative Growth, Development, Stress Response, and Fungicide Sensitivity of Fusarium graminearum.

Heme biosynthesis is a highly conserved pathway from bacteria to higher animals. Heme, which serves as a prosthetic group for various enzymes involved in multiple biochemical processes, is essential in almost all species, making heme homeostasis vital for life. However, studies on the biological functions of heme in filamentous fungi are scarce. In this study, we investigated the role of heme in Fusarium graminearum. A mutant lacking the rate-limiting enzymes in heme synthesis, coproporphyrinogen III oxidase (Cpo) or ferrochelatase (Fc), was constructed using a homologous recombination strategy. The results showed that the absence of these enzymes was lethal to F. graminearum, but the growth defect could be rescued by the addition of hemin, so we carried out further studies with the help of hemin. The results demonstrated that heme was required for the activity of FgCyp51, and its absence increased the sensitivity to tebuconazole and led to the upregulation of FgCYP51 in F. graminearum. Additionally, heme plays an indispensable role in the life cycle of F. graminearum, which is essential for vegetative growth, conidiation, external stress response (especially oxidative stress), lipid accumulation, fatty acid ß-oxidation, autophagy, and virulence.

Kinetics and molecular modeling studies on the inhibition mechanism of GH13 α-glycosidases by small molecule ligands.

Alpha-glucosidase inhibitors play an important role in Diabetes Mellitus (DM) treatment since they prevent postprandial hyperglycemia. The Glycoside Hydrolase family 13 (GH13) is the major family of enzymes acting on substrates containing α-glucoside linkages, such as maltose and amylose/amylopectin chains in starch. Previously, our group identified glycoconjugate 1H-1,2,3-triazoles (GCTs) inhibiting two GH13 α-glycosidases: yeast maltase (MAL12) and porcine pancreatic amylase (PPA). Here, we combined kinetic studies and computational methods on nine GCTs to characterize their inhibitory mechanism. They all behaved as reversible inhibitors, and kinetic models encompassed noncompetitive and various mechanisms of mixed-type inhibition for both enzymes. Most potent inhibitors displayed Ki values of 30 µM for MAL12 (GPESB16) and 37 µM for PPA (GPESB15). Molecular dynamics and docking simulations indicated that on MAL12, GPESB15 and GPESB16 bind in a cavity adjacent to the active site, while on the PPA, GPESB15 was predicted to bind at the entrance of the catalytic site. Notably, despite its putative location within the active site, the binding of GPESB15 does not obstruct the substrate's access to the cleavage site. Our study contributes to paving the way for developing novel therapeutic strategies for managing DM-2 through GH13 α-glycosidases inhibition.

Novel 4-triazole phenyl amide (4-TPA) molecules: Potent promoters of α-synuclein fibril disassembly.

Parkinson's disease profoundly compromises patients' daily lives, and the disassembly of α-synuclein aggregates, a primary pathological factor, represents a promising therapeutic approach. In this study, we conducted a systematic screening and optimization process to identify the novel scaffold B37, a 4-triazolyl-phenylamine derivative, exhibiting a potent disassembly activity of 1.1 µM against α-synuclein preformed fibrils. Notably, B37 demonstrated significant neuroprotective effects, ameliorated autophagic dysfunction induced by preformed fibrils, mitigated oxidative stress, and restored the co-localization of preformed fibrils with lysosomes. Transmission electron microscopy corroborated its in vitro disassembly function. Pharmacokinetic profiling revealed favorable parameters with a receptible blood-brain barrier permeability. B37 emerges as a promising lead compound for further optimization, aiming to develop a highly effective agent targeting the disassembly of α-synuclein aggregates to treat neurodegenerative diseases like Parkinson's disease.

Azoles activate type I and type II programmed cell death pathways in crop pathogenic fungi.

Triazoles are widely used to control pathogenic fungi. They inhibit the ergosterol biosynthetic pathway, but the precise mechanisms leading to fungicidal activities in many fungal pathogens are poorly understood. Here, we elucidate the mode of action of epoxiconazole and metconazole in the wheat pathogen Zymoseptoria tritici and the rice blast fungus Magnaporthe oryzae. We show that both azoles have fungicidal activity and reduce fluidity, but not integrity, of the plasma membrane. This impairs localisation of Cdc15-like F-BAR proteins, resulting in defective actin ring assembly and incomplete septation. However, mutant studies and pharmacological experiments in vitro and in planta show that azole lethality is due to a combination of reactive oxygen species-induced apoptosis and macroautophagy. Simultaneous inhibition of both programmed cell death pathways abolishes azole-induced cell death. Other classes of ergosterol biosynthesis inhibitors also induce apoptosis and macroautophagy, suggesting that activation of these two cell death pathways is a hallmark of ergosterol synthesis-targeting fungicides. This knowledge will inform future crop protection strategies.

The sterol C-24 methyltransferase encoding gene, erg6, is essential for viability of Aspergillus species.

Triazoles, the most widely used class of antifungal drugs, inhibit the biosynthesis of ergosterol, a crucial component of the fungal plasma membrane. Inhibition of a separate ergosterol biosynthetic step, catalyzed by the sterol C-24 methyltransferase Erg6, reduces the virulence of pathogenic yeasts, but its effects on filamentous fungal pathogens like Aspergillus fumigatus remain unexplored. Here, we show that the lipid droplet-associated enzyme Erg6 is essential for the viability of A. fumigatus and other Aspergillus species, including A. lentulus, A. terreus, and A. nidulans. Downregulation of erg6 causes loss of sterol-rich membrane domains required for apical extension of hyphae, as well as altered sterol profiles consistent with the Erg6 enzyme functioning upstream of the triazole drug target, Cyp51A/Cyp51B. Unexpectedly, erg6-repressed strains display wild-type susceptibility against the ergosterol-active triazole and polyene antifungals. Finally, we show that erg6 repression results in significant reduction in mortality in a murine model of invasive aspergillosis. Taken together with recent studies, our work supports Erg6 as a potentially pan-fungal drug target.

Dynamic Single-Cell RNA-Seq reveals mechanism of Selinexor-Resistance in Chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is a type of hematologic malignancies caused by BCR-ABL chimeric oncogene. Resistance to tyrosine kinase inhibitors (TKIs) leads to the progression of CML into advanced stages. Selinexor is a small molecule inhibitor that targets a nuclear transporter called Exportin 1. Combined with imatinib, selinexor has been shown to disrupt nuclear-cytoplasmic transport signal of leukemia stem cells, resulting in cell death. The objective of this study was to investigate the mechanism of drug resistance to selinexor in CML. We established K562 cell line resistant to selinexor and conducted single cell dynamic transcriptome sequencing to analyze the heterogeneity within the parental and selinexor resistant cell populations. We identified specific gene expression changes associated with resistance to selinexor. Our results revealed differential expression patterns in genes such as MT2A, TFPI, MTND3, and HMGCS1 in the total RNA, as well as MT-TW, DNAJB1, and HSPB1 in the newly synthesized RNA, between the parental and drug-resistant groups. By applying pseudo-time analysis, we discovered that a specific cluster of cells exhibited characteristics of tumor stem cells. Furthermore, we observed a gradual decrease in the expression of ferroptosis-related molecules as drug resistance developed. In vitro experiments confirmed that the combination of a ferroptosis inducer called RSL3 effectively overcame drug resistance. In conclusion, this study revealed the resistance mechanism of selinexor in CML. In conclusion, we identified a subgroup of CML cells with tumor stem cell properties and demonstrated that ferroptosis inducer improved the efficacy of selinexor in overcoming drug resistance.

Discovery of selective TYK2 inhibitors: Design, synthesis, in vitro and in silico studies of promising hits with triazolopyrimidinone scaffold.

The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway mediates many cytokine and growth factor signals. Tyrosine kinase 2 (TYK2), one of the members of this pathway and the first described member of the JAK family. TYK2 associates with inflammatory and autoimmune diseases, cancer and diabetes. Here, we present novel compounds as selective inhibitors of the canonical kinase domain of TYK2 enzyme. These compounds were rationally designed and synthesized with appropriate reactions. Molecular modeling techniques were used to design and optimize the candidates for TYK2 inhibition and to determine the estimated binding orientations of them inside JAKs. Designed compounds potently inhibited TYK2 with good selectivity against other JAKs as determined by in vitro assays. In order to verify its selectivity properties, compound A8 was tested against 58 human kinases (KinaseProfiler™ assay). The effects of the selected seven compounds on the protein levels of members of the JAK/STAT family were also detected in THP-1 monocytes although the basal level of these proteins is poorly detectable. Therefore, their expression was induced by lipopolysaccharide treatment and compounds A8, A15, A18, and A19 were found to be potent inhibitors of the TYK2 enzyme, (9.7 nM, 6.0 nM, 5.0 nM and 10.3 nM, respectively), and have high selectivity index for the JAK1, JAK2, and JAK3 enzymes. These findings suggest that triazolo[1,5-a]pyrimidinone derivatives may be lead compounds for developing potent TYK2-selective inhibitors targeting enzymes' active site.