[Advances in basic and clinical research of flumatinib].

Chronic myelogenous leukemia (CML) is a hematological malignancy originating from the pluripotent hematopoietic stem cells. Imatinib is the first generation of small molecule tyrosine kinase inhibitors (TKI) that revolutionized the treatment of CML. Flumatinib, as a novel oral TKI that independently developed in China, which can be used as a preferred treatment for CML. Basic researches suggested that the inhibitory effect of flumatinib on CML cell lines is stronger than imatinib. Flumatinib demonstrated that it has better efficacy than imatinib on CML in clinical trials and in real world studies. Flumatinib also showed a higher potency against CML with specific mutations, Ph(+) acute lymphoblastic leukemia and some solid tumors. The adverse events are manageable and tolerable.

Synthesis, Computational Study, and In Vitro α-Glucosidase Inhibitory Action of Thiourea Derivatives Based on 3-Aminopyridin-2(1H)-Ones.

Reactions with allyl-, acetyl-, and phenylisothiocyanate have been studied on the basis of 3-amino-4,6-dimethylpyridine-2(1H)-one, 3-amino-4-phenylpyridine-2-one, and 3-amino-4-(thiophene-2-yl)pyridine-2(1H)-one (benzoyl-)isothiocyanates, and the corresponding thioureide derivatives 8-11a-c were obtained. Twelve thiourea derivatives were obtained and studied for their anti-diabetic activity against the enzyme α-glucosidase in comparison with the standard drug acarbose. The comparison drug acarbose inhibits the activity of α-glucosidase at a concentration of 15 mM by 46.1% (IC50 for acarbose is 11.96 mM). According to the results of the conducted studies, it was shown that alkyl and phenyl thiourea derivatives 8,9a-c, in contrast to their acetyl-(benzoyl) derivatives and 10,11a-c, show high antidiabetic activity. Thus, 1-(4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)-3-phenylthiourea 9a has the highest inhibitory activity against the enzyme α-glucosidase, exceeding the activity of the comparison drug acarbose, which inhibits the activity of α-glucosidase by 56.6% at a concentration of 15 mm (IC50 = 9,77 mM). 1-(6-methyl-2-oxo 4-(thiophen-2-yl)-1,2-dihydropyridin-3-yl)-3-phenylthiourea 9c has inhibitory activity against the enzyme α-glucosidase, comparable to the comparison drug acarbose, inhibiting the activity of α-glucosidase at a concentration of 15 mm per 41.2% (IC50 = 12,94 mM). Compounds 8a, 8b, and 9b showed inhibitory activity against the enzyme α-glucosidase, with a lower activity compared to acarbose, inhibiting the activity of α-glucosidase at a concentration of 15 mM by 23.3%, 26.9%, and 35.2%, respectively. The IC50 against α-glucosidase for compounds 8a, 8b, and 9b was found to be 16.64 mM, 19.79 mM, and 21.79 mM, respectively. The other compounds 8c, 10a, 10b, 10c, 11a, 11b, and 11c did not show inhibitory activity against α-glucosidase. Thus, the newly synthesized derivatives of thiourea based on 3-aminopyridine-2(1H)-ones are promising candidates for the further modification and study of their potential anti-diabetic activity. These positive bioanalytical results will stimulate further in-depth studies, including in vivo models.

Aminopyridines in the development of drug candidates against protozoan neglected tropical diseases.

Neglected tropical diseases (NTDs) pose a major threat in tropical zones for impoverished populations. Difficulty of access, adverse effects or low efficacy limit the use of current therapeutic options. Therefore, development of new drugs against NTDs is a necessity. Compounds containing an aminopyridine (AP) moiety are of great interest for the design of new anti-NTD drugs due to their intrinsic properties compared with their closest chemical structures. Currently, over 40 compounds with an AP moiety are on the market, but none is used against NTDs despite active research on APs. The aim of this review is to present the medicinal chemistry work carried out with these scaffolds, against protozoan NTDs: Trypanosoma cruzi, Trypanosoma brucei or Leishmania spp.

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Strategy to Improve the Oral Pharmacokinetics of Cyclin-Dependent Kinase 4/6 Inhibitors: Enhancing Permeability and CYP450 Inhibition by a Natural Bioenhancer.

Palbociclib and ribociclib an orally bioavailable, potent cyclin-dependent kinase 4/6 inhibitors, with low oral bioavailability due to substrate specificity towards CYP3A and P-glycoprotein. Thus, current research aims to examine the effect of a bioenhancer (naringin), on oral pharmacokinetics of palbociclib and ribociclib. Naringin's affinity for CYP3A4 and P-glycoprotein was studied using molecular docking; its impact on palbociclib/ribociclib CYP3A metabolism and P-glycoprotein-mediated efflux was examined using in vitro preclinical models; and its oral pharmacokinetics in rats were assessed following oral administration of palbociclib/ribociclib in presence of naringin (50 and 100 mg/kg). Naringin binds optimally to both proteins with the highest net binding energy of - 1477.23 and - 1607.47 kcal/mol, respectively. The microsomal intrinsic clearance of palbociclib and ribociclib was noticeably reduced by naringin (5-100 µM), by 3.0 and 2.46-folds, respectively. Similarly, naringin had considerable impact on the intestinal transport and efflux of both drugs. The pre-treatment with 100 mg/kg naringin increased significantly (p < 0.05) the oral exposure of palbociclib (2.0-fold) and ribociclib (1.95-fold). Naringin's concurrent administration of palbociclib and ribociclib increased their oral bioavailability due to its dual inhibitory effect on CYP3A4 and P-glycoprotein; thus, concurrent naringin administration may represent an innovative strategy for enhancing bioavailability of cyclin-dependent kinase inhibitors.

CNS-wide repopulation by hematopoietic-derived microglia-like cells corrects progranulin deficiency in mice.

Hematopoietic stem cell transplantation can deliver therapeutic proteins to the central nervous system (CNS) through transplant-derived microglia-like cells. However, current conditioning approaches result in low and slow engraftment of transplanted cells in the CNS. Here we optimized a brain conditioning regimen that leads to rapid, robust, and persistent microglia replacement without adverse effects on neurobehavior or hematopoiesis. This regimen combines busulfan myeloablation and six days of Colony-stimulating factor 1 receptor inhibitor PLX3397. Single-cell analyses revealed unappreciated heterogeneity of microglia-like cells with most cells expressing genes characteristic of homeostatic microglia, brain-border-associated macrophages, and unique markers. Cytokine analysis in the CNS showed transient inductions of myeloproliferative and chemoattractant cytokines that help repopulate the microglia niche. Bone marrow transplant of progranulin-deficient mice conditioned with busulfan and PLX3397 restored progranulin in the brain and eyes and normalized brain lipofuscin storage, proteostasis, and lipid metabolism. This study advances our understanding of CNS repopulation by hematopoietic-derived cells and demonstrates its therapeutic potential for treating progranulin-dependent neurodegeneration.

Comparative biological activity of palbociclib and ribociclib in hormone receptor-positive breast cancer.

This study examines the biological effects of palbociclib and ribociclib in hormone receptor-positive breast cancer, pivotal to the HARMONIA prospective phase III clinical trial. We explore the downstream impacts of these CDK4/6 inhibitors, focusing on cell lines and patient-derived tumor samples. We treated HR+ breast cancer cell lines (T47D, MCF7, and BT474) with palbociclib or ribociclib (100 nM or 500 nM), alone or combined with fulvestrant (1 nM), over periods of 24, 72, or 144 h. Our assessments included PAM50 gene expression, RB1 phosphorylation, Lamin-B1 protein levels, and senescence-associated ß-galactosidase activity. We further analyzed PAM50 gene signatures from the CORALLEEN and NeoPalAna phase II trials. Both CDK4/6 inhibitors similarly inhibited proliferation across the cell lines. At 100 nM, both drugs partially reduced p-RB1, with further decreases at 500 nM over 144 h. Treatment led to reduced Lamin-B1 expression and increased senescence-associated ß-galactosidase activity. Both drugs enhanced Luminal A and reduced Luminal B and proliferation signatures at both doses. However, the HER2-enriched signature significantly diminished only at the higher dose of 500 nM. Corresponding changes were observed in tumor samples from the CORALLEEN and NeoPalAna studies. At 2 weeks of treatment, both drugs significantly reduced the HER2-enriched signature, but at surgery, this reduction was consistent only with ribociclib. Our findings suggest that while both CDK4/6 inhibitors effectively modulate key biological pathways in HR+/HER2- breast cancer, nuances in their impact, particularly on the HER2-enriched signature, are dose-dependent, influenced by the addition of fulvestrant and warrant further investigation.

IC Regimen: Delaying Resistance to Lorlatinib in ALK Driven Cancers by Adding Repurposed Itraconazole and Cilostazol.

Lorlatinib is a pharmaceutical ALK kinase inhibitor used to treat ALK driven non-small cell lung cancers. This paper analyses the intersection of past published data on the physiological consequences of two unrelated drugs from general medical practice-itraconazole and cilostazol-with the pathophysiology of ALK positive non-small cell lung cancer. A conclusion from that data analysis is that adding itraconazole and cilostazol may make lorlatinib more effective. Itraconazole, although marketed worldwide as a generic antifungal drug, also inhibits Hedgehog signaling, Wnt signaling, hepatic CYP3A4, and the p-gp efflux pump. Cilostazol, marketed worldwide as a generic thrombosis preventative drug, acts by inhibiting phosphodiesterase 3, and, by so doing, lowers platelets' adhesion, thereby partially depriving malignant cells of the many tumor trophic growth factors supplied by platelets. Itraconazole may enhance lorlatinib effectiveness by (i) reducing or stopping a Hedgehog-ALK amplifying feedback loop, by (ii) increasing lorlatinib's brain levels by p-gp inhibition, and by (iii) inhibiting growth drive from Wnt signaling. Cilostazol, surprisingly, carries minimal bleeding risk, lower than that of aspirin. Risk/benefit assessment of the combination of metastatic ALK positive lung cancer being a low-survival disease with the predicted safety of itraconazole-cilostazol augmentation of lorlatinib favors a trial of this drug trio in ALK positive lung cancer.

Targeting TANK-binding kinase 1 attenuates painful diabetic neuropathy via inhibiting microglia pyroptosis.

BACKGROUND: Painful diabetic neuropathy (PDN) is closely linked to inflammation, which has been demonstrated to be associated with pyroptosis. Emerging evidence has implicated TANK-binding kinase 1 (TBK1) in various inflammatory diseases. However, it remains unknown whether activated TBK1 causes hyperalgesia via pyroptosis. METHODS: PDN mice model of type 1 or type 2 diabetic was induced by C57BL/6J or BKS-DB mice with Lepr gene mutation. For type 2 diabetes PDN model, TBK1-siRNA, Caspase-1 inhibitor Ac-YVAD-cmk or TBK1 inhibitor amlexanox (AMX) were delivered by intrathecal injection or intragastric administration. The pain threshold and plantar skin blood perfusion were evaluated through animal experiments. The assessments of spinal cord, dorsal root ganglion, sciatic nerve, plantar skin and serum included western blotting, immunofluorescence, ELISA, and transmission electron microscopy. RESULTS: In the PDN mouse model, we found that TBK1 was significantly activated in the spinal dorsal horn (SDH) and mainly located in microglia, and intrathecal injection of chemically modified TBK1-siRNA could improve hyperalgesia. Herein, we described the mechanism that TBK1 could activate the noncanonical nuclear factor κB (NF-κB) pathway, mediate the activation of NLRP3 inflammasome, trigger microglia pyroptosis, and ultimately induce PDN, which could be reversed following TBK1-siRNA injection. We also found that systemic administration of AMX, a TBK1 inhibitor, could effectively improve peripheral nerve injury. These results revealed the key role of TBK1 in PDN and that TBK1 inhibitor AMX could be a potential strategy for treating PDN. CONCLUSIONS: Our findings revealed a novel causal role of TBK1 in pathogenesis of PDN, which raises the possibility of applying amlexanox to selectively target TBK1 as a potential therapeutic strategy for PDN.

Synergistic Enhancement of Antitumor Effects by Combining Abemaciclib with Desipramine.

Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors, including abemaciclib, have been approved for the treatment of hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced, and metastatic breast cancer. Despite the high therapeutic efficacy of CDK4/6 inhibitors, they are associated with various adverse effects, including potentially fatal interstitial lung disease. Therefore, a combination of CDK4/6 inhibitors with letrozole or fulvestrant has been attempted but has demonstrated limitations in reducing adverse effects, highlighting the need to develop new combination therapies. This study proposes a combination strategy using CDK4/6 inhibitors and tricyclic antidepressants to enhance the therapeutic outcomes of these inhibitors while reducing their side effects. The therapeutic efficacies of abemaciclib and desipramine were tested in different cancer cell lines (H460, MCF7, and HCT-116). The antitumor effects of the combined abemaciclib and desipramine treatment were evaluated in a xenograft colon tumor model. In vitro cell studies have shown the synergistic anticancer effects of combination therapy in the HCT-116 cell line. The combination treatment significantly reduced tumor size compared with control or single treatment without causing apparent toxicity to normal tissues. Although additional in vivo studies are necessary, this study suggests that the combination therapy of abemaciclib and desipramine may represent a novel therapeutic approach for treating solid tumors.

HER4 Affects Sensitivity to Tamoxifen and Abemaciclib in Luminal Breast Cancer Cells and Restricts Tumor Growth in MCF-7-Based Humanized Tumor Mice.

The impact of the HER4 receptor on the growth and treatment of estrogen receptor-positive breast cancer is widely uncertain. Using CRISPR/Cas9 technology, we generated stable HER4 knockout variants derived from the HER4-positive MCF-7, T-47D, and ZR-75-1 breast cancer cell lines. We investigated tumor cell proliferation as well as the cellular and molecular mechanisms of tamoxifen, abemaciclib, AMG232, and NRG1 treatments as a function of HER4 in vitro. HER4 differentially affects the cellular response to tamoxifen and abemaciclib treatment. Most conspicuous is the increased sensitivity of MCF-7 in vitro upon HER4 knockout and the inhibition of cell proliferation by NRG1. Additionally, we assessed tumor growth and immunological effects as responses to tamoxifen and abemaciclib therapy in humanized tumor mice (HTM) based on MCF-7 HER4-wildtype and the corresponding HER4-knockout cells. Without any treatment, the enhanced MCF-7 tumor growth in HTM upon HER4 knockout suggests a tumor-suppressive effect of HER4 under preclinical but human-like conditions. This phenomenon is associated with an increased HER2 expression in MCF-7 in vivo. Independent of HER4, abemaciclib and tamoxifen treatment considerably inhibited tumor growth in these mice. However, abemaciclib-treated hormone receptor-positive breast cancer patients with tumor-associated mdm2 gene copy gains or pronounced HER4 expression showed a reduced event-free survival. Evidently, the presence of HER4 affects the efficacy of tamoxifen and abemaciclib treatment in different estrogen receptor-positive breast cancer cells, even to different extents, and is associated with unfavorable outcomes in abemaciclib-treated patients.

Pexidartinib and Immune Checkpoint Inhibitors Combine to Activate Tumor Immunity in a Murine Colorectal Cancer Model by Depleting M2 Macrophages Differentiated by Cancer-Associated Fibroblasts.

Tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs) are known to play supportive roles in tumor development and progression, but their interactions in colorectal cancer (CRC) remain unclear. Here, we investigated the effects of colon-cancer-derived CAFs on TAM differentiation, migration, and tumor immunity, both in vitro and in vivo. When co-cultured with monocytes, CAFs attracted monocytes and induced their differentiation into M2 macrophages. Immunohistology of surgically resected human CRC specimens and orthotopically transplanted mouse tumors revealed a correlation between numbers of CAFs and numbers of M2 macrophages. In a mouse model of CRC orthotopic transplantation, treatment with an inhibitor of the colony-stimulating factor-1 receptor (PLX3397) depleted M2 macrophages and increased CD8-positive T cells infiltrating the tumor nest. While this treatment had a minor effect on tumor growth, combining PLX3397 with anti-PD-1 antibody significantly reduced tumor growth. RNA-seq following combination therapy showed activation of tumor immunity. In summary, CAFs are involved in the induction and mobilization of M2 macrophage differentiation in the CRC tumor immune microenvironment, and the combination of cancer immunotherapy and PLX3397 may represent a novel therapeutic option for CRC.

Trans vs. cis: a computational study of enasidenib resistance due to IDH2 mutations.

Isocitrate dehydrogenase 2 (IDH2) is a homodimeric enzyme that plays an important role in energy production. A mutation R140Q in one monomer makes the enzyme tumourigenic. Enasidenib is an effective inhibitor of IDH2/R140Q. A secondary mutation Q316E leads to enasidenib resistance. This mutation was hitherto only found in trans, i.e. where one monomer has the R140Q mutation and the other carries the Q316E mutation. It is not clear if the mutation only leads to resistance when in trans or if it has been discovered in trans only by chance, since it was only reported in two patients. Using molecular dynamics (MD) simulations we show that the binding of enasidenib to IDH2 is indeed much weaker when the Q316E mutation takes place in trans not in cis, which provides a molecular explanation for the clinical finding. This is corroborated by non-covalent interaction (NCI) analysis and DFT calculations. Whereas the MD simulations show a loss of one hydrogen bond upon the resistance mutation, NCI and energy decomposition analysis (EDA) reveal that a multitude of interactions are weakened.

Development of a Radiolabeled Cyclin-Dependent Kinases 4 and 6 (CDK4/6) Inhibitor for Brain and Cancer PET Imaging.

The synthesis, biochemical evaluation and radiosynthesis of a cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitor and radioligand was performed. NT431, a newly synthesized 4-fluorobenzyl-abemaciclib, exhibited high potency to CDK4/6 and against four cancer cell lines with IC50 similar to that of the parent abemaciclib. We performed a two-step one-pot radiosynthesis to produce [18F]NT431 with good radiochemical yield (9.6 ± 3%, n = 3, decay uncorrected), high radiochemical purity (>95%), and high molar activity (>370 GBq/µmol (>10.0 Ci/µmol). In vitro autoradiography confirmed the specific binding of [18F]NT431 to CDK4/6 in brain tissues. Dynamic PET imaging supports that both [18F]NT431 and the parent abemaciclib crossed the BBB albeit with modest brain uptake. Therefore, we conclude that it is unlikely that NT431 or abemaciclib (FDA approved drug) can accumulate in the brain in sufficient concentrations to be potentially effective against breast cancer brain metastases or brain cancers. However, despite the modest BBB penetration, [18F]NT431 represents an important step towards the development and evaluation of a new generation of CDK4/6 inhibitors with superior BBB penetration for the treatment and visualization of CDK4/6 positive tumors in the CNS. Also, [18F]NT431 may have potential application in peripheral tumors such as breast cancer and other CDK4/6 positive tumors.

Potentiation of BKCa channels by cystic fibrosis transmembrane conductance regulator correctors VX-445 and VX-121.

Cystic fibrosis results from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) anion channel, ultimately leading to diminished transepithelial anion secretion and mucociliary clearance. CFTR correctors are therapeutics that restore the folding/trafficking of mutated CFTR to the plasma membrane. The large-conductance calcium-activated potassium channel (BKCa, KCa1.1) is also critical for maintaining lung airway surface liquid (ASL) volume. Here, we show that the class 2 (C2) CFTR corrector VX-445 (elexacaftor) induces K+ secretion across WT and F508del CFTR primary human bronchial epithelial cells (HBEs), which was entirely inhibited by the BKCa antagonist paxilline. Similar results were observed with VX-121, a corrector under clinical evaluation. Whole-cell patch-clamp recordings verified that CFTR correctors potentiated BKCa activity from both primary HBEs and HEK cells stably expressing the α subunit (HEK-BK cells). Furthermore, excised patch-clamp recordings from HEK-BK cells verified direct action on the channel and demonstrated a significant increase in open probability. In mouse mesenteric artery, VX-445 induced a paxilline-sensitive vasorelaxation of preconstricted arteries. VX-445 also reduced firing frequency in primary rat hippocampal and cortical neurons. We raise the possibilities that C2 CFTR correctors gain additional clinical benefit by activation of BKCa in the lung yet may lead to adverse events through BKCa activation elsewhere.

Microglia mediate the increase in slow-wave sleep associated with high ambient temperature.

An increase in ambient temperature leads to an increase in sleep. However, the mechanisms behind this phenomenon remain unknown. This study aimed to investigate the role of microglia in the increase of sleep caused by high ambient temperature. We confirmed that at 35 °C, slow-wave sleep was significantly increased relative to those observed at 25 °C. Notably, this effect was abolished upon treatment with PLX3397, a CSF1R inhibitor that can deplete microglia, while sleep amount at 25 °C was unaffected. These observations suggest that microglia play a pivotal role in modulating the homeostatic regulation of sleep in response to the fluctuations in ambient temperature.

Microglial repopulation induced by PLX3397 protects against ischemic brain injury by suppressing neuroinflammation in aged mice.

As the resident immune cells in the central nervous system, microglia exhibit a 'sensitized' or 'primed' phenotype with dystrophic morphology and dysregulated functions in aged brains. Although studies have demonstrated the inflammatory profile of aged microglia in several neurological diseases, this issue is largely uncertain in stroke. Consequently, this study investigated the effects of primed and repopulated microglia on post-ischemic brain injury in aged mice. We replaced primed microglia with newly repopulated microglia through pharmacological administration and withdrawal of the colony-stimulating factor 1 receptor (CSF1R) inhibitor, PLX3397. Further, we performed a series of behavioral tests and flow cytometry in mouse models of middle cerebral artery occlusion (MCAO) to study the effects of microglial replacement on ischemic injury in the aged brain. With depletion and subsequent repopulation of microglia in MCAO mice, microglial replacement in aged mice improved neurological function and decreased brain infarction. This protective effect was accompanied by the reduction of peripheral immune cells infiltrating into brains. We showed that the repopulated microglia expressed elevated neuroprotective factors (including Cluster of Differentiation 206, transforming growth factor-ß, and interleukin-10) and diminished expression of inflammatory markers (including Cluster of Differentiation 86, interleukin-6, and tumor necrosis factor α). Moreover, microglial replacement protected the blood-brain barrier and relieved neuronal death in aged mice subjected to 60 min of MCAO. These results imply that the replacement of microglia in the aged brain may alleviate brain damage and neuroinflammation, and therefore, ischemic brain damage. Thus, targeting microglia could be a promising therapeutic strategy for ischemic stroke.

A pathological study on the efficacy of Syk inhibitors in a Candida albicans-induced aortic root vasculitis murine model.

BACKGROUND: The activation of innate immunity may be involved in the development of Candida albicans-induced murine vasculitis, which resembles Kawasaki disease (KD) vasculitis. This study aimed to histologically clarify the time course of the development of vasculitis in this model in detail and to estimate the potential role of spleen tyrosine kinase (Syk) inhibitors in KD vasculitis. METHODS AND RESULTS: DBA/2 male mice were intraperitoneally injected with a vasculitis-inducing substance and treated with a Syk inhibitor (R788 or GS-9973). Systemic vasculitis, especially in the aortic annulus area, was histologically evaluated. Regarding lesions in the aortic annulus area, some mice in the untreated control group already showed initiation of vasculitis 1 day after the final injection of a vasculitis-inducing substance. The vasculitis expanded over time. Inflammation occurred more frequently at the aortic root than at the coronary artery. The distribution of inflammatory cells was limited to the intima, intima plus adventitia, or all layers. In the Syk inhibitor-treated groups, only one mouse had vasculitis at all observation periods. The severity and area of the vasculitis were reduced by both Syk inhibitors. CONCLUSION: Candida albicans-induced murine vasculitis may occur within 1 day after the injection of a vasculitis-inducing substance. Additionally, Syk inhibitors suppress murine vasculitis.

Successful intracranial response of lorlatinib after resistance with alectinib and brigatinib in patients with ALK-positive lung adenocarcinoma: Implications of CNS penetration rate of brigatinib.

We present the case of a 34-year-old Japanese man with anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer and brain metastases. After central nervous system (CNS) disease progression with alecintib and brigatinib, treatment with lorlatinib resulted in a good intracranial response. In this case, we investigated brain penetration ratio of brigatinib using cerebrospinal fluid and paired serum samples, and the ratio was 0.012. Further, we investigated resistance mechanisms via next-generation sequencing (NGS) using lung biopsy at lung cancer diagnosis and brain biopsy sample at progressive disease of brigatinib. No apparent resistance mechanism of known ALK resistance, such as ALK mutations, amplifications, epithelial-mesenchymal transition (EMT) and bypass pathway activation were detected. Taken together, we speculate that the low CNS penetration rate of brigatinib confers CNS progression. Further studies are warranted to reveal the resistance mechanism and propose a treatment strategy for CNS progression in ALK-positive patients.

Synthesis of novel aryl-substituted 2-aminopyridine derivatives by the cascade reaction of 1,1-enediamines with vinamidinium salts to develop novel anti-Alzheimer agents.

Alzheimer's disease (AD), a severe neurodegenerative disorder, imposes socioeconomic burdens and necessitates innovative therapeutic strategies. Current therapeutic interventions are limited and underscore the need for novel inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), enzymes implicated in the pathogenesis of AD. In this study, we report a novel synthetic strategy for the generation of 2-aminopyridine derivatives via a two-component reaction converging aryl vinamidinium salts with 1,1-enediamines (EDAMs) in a dimethyl sulfoxide (DMSO) solvent system, catalyzed by triethylamine (Et3N). The protocol introduces a rapid, efficient, and scalable synthetic pathway, achieving good to excellent yields while maintaining simplistic workup procedures. Seventeen derivatives were synthesized and subsequently screened for their inhibitory activity against AChE and BChE. The most potent derivative, 3m, exhibited an IC50 value of 34.81 ± 3.71 µM against AChE and 20.66 ± 1.01 µM against BChE compared to positive control donepezil with an IC50 value of 0.079 ± 0.05 µM against AChE and 10.6 ± 2.1 µM against BChE. Also, detailed kinetic studies were undertaken to elucidate their modes of enzymatic inhibition of the most potent compounds against both AChE and BChE. The promising compound was then subjected to molecular docking and dynamics simulations, revealing significant binding affinities and favorable interaction profiles against AChE and BChE. The in silico ADMET assessments further determined the drug-like properties of 3m, suggesting it as a promising candidate for further pre-clinical development.

Lumacaftor as a potential repurposed drug in targeting breast cancer stem cells: insights from in silico study.

CONTEXT: Breast cancer stem cells (BCSCs) are a small subset of cells within breast tumors with characteristics similar to normal stem cells. Despite advancements in chemotherapy and targeted therapy for breast cancer, the prognosis for breast cancer patients has remained poor due to drug resistance, reoccurrence, and metastasis. Growing evidence suggests that deregulation of the self-renewal pathways, like the Wnt signaling pathway mediated by ß-catenin, plays a crucial role in the survival of breast cancer stem cells. Targeting the Wnt signaling pathway in breast cancer stem cells offers a promising avenue for developing effective therapeutic strategies targeting these cells, potentially leading to improved patient outcomes and reduced tumor recurrence. METHODS: For this purpose, we have screened a 1615 FDA-approved drug library against our target protein, ß-catenin, which is involved in the Wnt signaling pathway using molecular docking analysis, molecular dynamics (MD) simulations, and molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) calculations. RESULTS: Molecular docking studies showed that the Lumacaftor- ß-catenin complex had the lowest docking score of - 8.7 kcal/mol towards ß-catenin protein than the reference inhibitor. Molecular dynamic simulations and MM/PBSA calculations were also performed for the Lumacaftor-ß-catenin complex to establish the stability of the interactions involved. Considering its promising attributes and encouraging results, Lumacaftor holds significant potential as a novel therapeutic option to target BCSCs. This study opens avenues for further investigation and may pave the way for developing therapeutic potential in breast cancer treatment. Further confirmation is warranted through in vitro and clinical studies to validate the findings of this study.