Search Results (2,870)

Kinases, which make up 20% of the druggable genome, are thought to be essential signaling enzymes. Protein phosphorylation is induced by protein kinases. Proliferation, the cell cycle, apoptosis, motility, growth, differentiation, and other biological processes are all regulated by kinases. Their dysregulation disrupts several cellular functions, leading to a variety of illnesses, the most important of which is cancer. As a result, kinases are thought to be crucial targets in a number of malignancies and other diseases. Researchers from all over the world are hard at work developing inhibitors using various chemical structures. The scaffolds of imidazole and benzimidazole provide a versatile structure for a variety of physiologically active substances. Moreover, they serve as specialized scaffolding for the creation of target-specific pharmaceuticals to address various diseases. This article seeks to illustrate the application of imidazole and benzimidazole frameworks in the formulation of inhibitors that target various tyrosine kinases, including fibroblast growth factor receptors (FGFRs), c-Met kinase, epidermal growth factor receptors (EGFRs), vascular endothelial growth factor receptors (VEGFRs), and FMS-like tyrosine kinase 3 (FLT3), from 2020 to the present. The major structure–activity correlations (SARs) of imidazole and benzimidazole derivatives were examined, and, also, a docking study highlighted the varied interactions occurring inside the active site of tyrosine protein kinases. The objective of this effort is to consolidate the fundamental structural information necessary for the synthesis of imidazole- or benzimidazole-based tyrosine kinase inhibitors with enhanced efficacy. Full article

Background: Nintedanib (NIN), an intracellular inhibitor of tyrosine kinases that inhibits processes fundamental to the progression of pulmonary fibrosis (PPF), is used in the treatment of patients with PPF associated with systemic sclerosis. During NIN therapy, adverse events lead to a permanent dose reduction and treatment discontinuation. Therapeutic drug monitoring (TDM) can be used to manage and optimize drug administration based on the measurement of drug concentrations. Therefore, TDM can be helpful in minimizing the impact of adverse events and help patients remain in therapy. The aim of this study was to develop and validate a new bioanalytical UPLC-MS/MS method enabling the determination of NIN and its active metabolite in the plasma of patients with PPF associated with systemic sclerosis. Methods: Sample preparation was carried out using protein precipitation with an extraction mixture: acetonitrile neutralized with 2 M sodium carbonate. Analytes and the internal standard (intedanib-d3) were monitored using mass spectrometry (MS) and positive-ion-mode electrospray ionization by MRM. Chromatographic analysis was performed on a Zorbax SB-C18 column kept at 40 °C using isocratic elution. The mobile phase contained 0.1% formic acid in water; acetonitrile (35:65 v/v) was pumped at a flow rate of 0.3 mL/min. The analysis time was 5 min. Results: The method was verified according to the EMA guidelines over a concentration range of 2.00–200.00 ng/mL. The correlation coefficients for the calibration curves were found to be 0.9991 and 0.9957 for NIN and its metabolite BIBF 1202, respectively. The within- and between-run precision and accuracy of LLOQ were evaluated for NIN and BIBF 1202 to be within RSD 2.96%, 4.53%, 5.51%, and 6.72% and in the ranges of 102.2–107.3%, 98.0–101.8%, 104.3–114.2%, and 99.1–104.9, respectively. The stability of the analytes in plasma after 4 h at 30 °C was found to be satisfactory, meeting the assumed bias criteria below 15%. Conclusions: The proposed method was successfully applied to analyze two active compounds—NIN and BIBF 1202—in plasma samples at two time points: trough (pre-dose concentration) and 2–3 h (maximum concentration) after the administration of NIN. Full article

Ibrutinib (IB), a Bruton’s tyrosine kinase (BTK) inhibitor, is widely used against B-cell malignancies. However, its adverse effects on stem cell-dependent processes and tissue homeostasis remain incompletely understood. Freshwater planarians possess pluripotent stem cells (neoblasts), which enable remarkable regeneration of various tissues, including the central nervous system. This makes them ideal in vivo models for studying chemical toxicity within a whole-organism context. Here, we utilized planarian Dugesia constrictiva to assess IB toxicity and elucidate its mechanisms, focusing on its impact on stem cell dynamics and regeneration. Our results demonstrated that exposure to IB at concentrations as low as 0.9 mg/L, far below clinical plasma levels, led to severe morphological and regenerative impairments, including disrupted neural regeneration. Mechanistically, IB disrupted stem cell dynamics by suppressing proliferation and differentiation and by inducing oxidative stress via ROS overproduction. Notably, IB exposure significantly downregulated BTK expression. Crucially, BTK RNAi caused the key toxic effects of IB exposure, including morphological and regenerative defects, suppression of stem cell proliferation and differentiation, and increased apoptosis. Therefore, we conclude that IB may exert its toxicity in planarians primarily through BTK inhibition. This finding provides direct functional evidence linking BTK inhibition to stem cell dysfunction and regenerative defects in a novel in vivo context, offering critical insights for refining the clinical safety profile of IB. Full article

Artificial neural networks in drug discovery have shown remarkable potential in various areas, including molecular similarity assessment and virtual screening. This study presents a novel multimodal Siamese neural network architecture. The aim was to join molecular electrostatic potential (MEP) images with the texture features derived from reduced density gradient (RDG) diagrams for enhanced molecular similarity prediction. On one side, the proposed model is combined with a convolutional neural network (CNN) for processing MEP visual information. This data is added to the multilayer perceptron (MLP) that extracts texture features from gray-level co-occurrence matrices (GLCM) computed from RDG diagrams. Both representations converge through a multimodal projector into a shared embedding space, which was trained using triplet loss to learn similarity and dissimilarity patterns. Limitations associated with the use of purely structural descriptors were overcome by incorporating non-covalent interaction information through RDG profiles, which enables the identification of bioisosteric relationships needed for rational drug design. Three datasets were used to evaluate the performance of the developed model: tyrosine kinase inhibitors (TKIs) targeting the mutant T315I BCR-ABL receptor for the treatment of chronic myeloid leukemia, acetylcholinesterase inhibitors (AChEIs) for Alzheimer’s disease therapy, and heterodimeric AChEI candidates for cross-validation. The visual and texture features of the Siamese architecture help in the capture of molecular similarities based on electrostatic and non-covalent interaction profiles. Therefore, the developed protocol offers a suitable approach in computational drug discovery, being a promising framework for virtual screening, drug repositioning, and the identification of novel therapeutic candidates. Full article

Background/Objectives: Hepatocellular carcinoma (HCC) therapies are limited by poor response, rapid resistance, and recurrence of aggressive disease. Sorafenib, a multi-tyrosine kinase inhibitor, can trigger β-catenin stabilization and activation, contributing to resistance. Overexpression of the chemokine receptor CXCR6 and its ligand CXCL16 and hyperactivation are implicated in HCC progression and β-catenin stabilization. We hypothesized that SBI-457, a small-molecule CXCR6 antagonist we developed, could disrupt CXCR6/β-catenin crosstalk and enhance sorafenib sensitivity. Methods: We tested SBI-457 alone and in combination with sorafenib in SK-Hep-1 xenograft models and a panel of human HCC cell lines. Tumor burden, β-catenin activation, and CXCR6 expression were assessed by tumor volume measurements, immunohistochemistry, Western blotting, and immunofluorescence. Soluble CXCL16 levels were quantified by ELISA, and cell death responses were evaluated using MTT assays. Results: In vivo, SBI-457 combined with sorafenib reduced normalized tumor volume by 55% compared to vehicle controls, modestly exceeding monotherapy effects, and attenuated sorafenib-induced β-catenin upregulation. In vitro, SBI-457 blocked nuclear accumulation of β-catenin and reversed sorafenib-induced increases in β-catenin levels. Enhanced cell death was observed in specific “responder” HCC cell lines (Hep-3B, SNU-398, JHH-5), which correlated with high intracellular β-catenin, secretion of soluble CXCL16, and expression of a high molecular weight form of CXCR6. In contrast, “non-responder” cell lines with conventional CXCR6 expression and low CXCL16 secretion showed no enhanced cell death response. Conclusions: CXCR6 antagonism with SBI-457 can modulate β-catenin activation and may help overcome sorafenib resistance in selected HCC models. These findings support further development of CXCR6 antagonists as single agents or combination therapies to improve treatment outcomes in HCC. Full article

Anaplastic lymphoma kinase (ALK), a member of the receptor tyrosine kinase family, plays a central oncogenic role in the initiation and progression of diverse malignancies. Aberrant ALK activation generally results from structural alterations or dysregulated expression, leading to persistent activation of downstream signaling pathways that drive tumor cell proliferation, survival, and metastasis. ALK gene abnormalities predominantly encompass fusions, point mutations, and amplifications, with EML4-ALK-positive non–small cell lung cancer representing a canonical example. The advent of ALK-targeted inhibitors has constituted a major therapeutic milestone for ALK-positive tumors. From first-generation Crizotinib to third-generation Lorlatinib, successive agents have been refined for target selectivity, central nervous system penetration, and coverage of resistance-associated mutations, substantially improving patient survival and intracranial disease control. Nonetheless, the emergence of acquired resistance remains an overarching challenge, mediated by secondary kinase domain mutations, activation of bypass signaling pathways, and tumor phenotypic transformation. This review presents an integrative synthesis of ALK-targeted therapeutic developments, elucidates underlying resistance mechanisms, and surveys emerging strategies, providing a comprehensive perspective on current advances and future directions in precision management of ALK-driven malignancies. Full article

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract and a key example for targeted therapy with tyrosine kinase inhibitors (TKIs), which have significantly improved survival rates. However, no effective treatments exist for TKI-resistant or mutation-negative tumours. Until now, research on the effects of TKIs has mainly used 2D cultures or mouse models, lacking patient-specific 3D GIST models. We investigated various 3D GIST models, including spheroids, organoids, patient-derived microtumours (PDMs), and precision-cut tumour slices (PCTSs), to assess their feasibility as alternatives for 2D cell culture or in vivo mouse models. Moreover, 2D monolayer and 3D spheroid GIST cell lines showed mutation-dependent responses to TKI treatment, but differences between 2D and 3D cultures were minimal. Thus, patient-derived 3D models, incorporating tumour microenvironment cells, were developed for more accurate in vivo representation. PDMs and PCTSs were successfully isolated from primary tumours and cultivated for up to two weeks. Three-dimensional models were immunohistochemically characterised, and the response to TKI therapies was tested and compared with expected clinical outcomes. In addition to already established 2D cell cultures and mouse models, PDMs and PCTSs are novel patient-derived 3D models that can be used to study tumour cell interactions within the microenvironment. Moreover, they could be used to investigate TKI resistance, and novel treatment options such as immunotherapies and combination therapies. Full article

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy with a five-year survival rate of 3–15% and limited effective treatment options for most patients. Approximately 5–10% of cases are wild-type KRAS and are more likely to harbor rare alterations, including gene fusions involving anaplastic lymphoma kinase (ALK), ROS Proto-Oncogene 1 (ROS1), neurotrophic tyrosine receptor kinase (NTRK), Rearranged During Transfection (RET), Fibroblast Growth Factor Receptor (FGFR), or Neuregulin 1 (NRG1) genes, as well as germline mutations in DNA repair genes. This review integrates current evidence on the prevalence, molecular profile, and clinical significance of gene fusions, amplification, and somatic/germline mutations in PDAC, with a particular focus on the wild-type KRAS subgroup. Clinical trial data and case reports indicate that these alterations can enhance patient susceptibility to targeted therapies. Currently, selpercatinib, larotrectinib, and repotrectinib are approved by the FDA for the treatment of certain solid tumors harboring specific gene fusions. Recent studies on zenocutuzumab resulted in the FDA-accelerated approval for NGR1 fusion-positive NSCLC and PDAC. Germline mutations may specifically increase responsiveness to poly(ADP-ribose) polymerase (PARP) inhibitors or platinum-based treatments. Comprehensive genomic profiling, incorporating fusion detection and germline testing, is essential to identify patients who may benefit from precision-based approaches. Full article

Tyrosine kinases (TKs) and cyclin-dependent kinases (CDKs) contain reactive cysteines that can be exploited by targeted covalent inhibitors. In this exploratory computational study, we asked whether selected natural-product-like (NP-like) electrophiles bearing Michael-acceptor (MA) motifs could adopt geometries consistent with covalent approaches to these cysteines, in a manner analogous to approved covalent TKIs. Using AutoDockFR with cysteine-centered grids and explicit side-chain flexibility, we performed pocket-focused, within-receptor covalent docking for EGFR, VEGFR2/KDR, PDGFRβ (via PDGFRα surrogate), BTK, CDK7, and CDK12. Reference inhibitors (osimertinib–EGFR, ibrutinib–BTK, THZ1–CDK7, and THZ531–CDK12) reproduced the expected geometries and served as internal controls. NP-like electrophiles (parthenolide, withaferin A, celastrol, and curcumin as a low-reactivity geometry probe) displayed pocket-compatible orientations in several targets, particularly EGFR and BTK, suggesting feasible pre-reaction alignment toward the reactive cysteine. Although no quantitative affinity was inferred, the consistent geometric feasibility supports their potential as structural templates for covalent-binding natural scaffolds. These results provide a qualitative, structure-based rationale for further chemoproteomic and enzymatic validation of NP-derived or hybrid compounds as potential leads in cancer therapy, expanding covalent chemical space beyond existing synthetic scaffolds. Full article

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy, characterized by the clonal proliferation of immature lymphoid precursors. The distinction between B-cell ALL (B-ALL) and T-cell ALL (T-ALL) is fundamental, as each subtype exhibits distinct cytomorphological, genetic, and clinical features influencing prognosis and therapeutic strategies. Conventional multi-phase chemotherapy has significantly improved survival rates, yet its efficacy is limited by severe short- and long-term toxicities, highlighting the need for more selective therapeutic approaches. Advances in molecular profiling have enabled the identification of key oncogenic pathways, paving the way for targeted therapies such as tyrosine kinase inhibitors (TKIs), JAK-STAT pathway inhibitors, BCL-2 antagonists, and agents modulating epigenetic and cell cycle regulators. Concurrently, immunotherapeutic strategies have transformed the therapeutic landscape of pediatric ALL. Bispecific antibodies such as blinatumomab (anti-CD19), antibody–drug conjugates like inotuzumab ozogamicin (anti-CD22), and monoclonal antibodies such as daratumumab (anti-CD38) have demonstrated efficacy in relapsed or refractory disease with improved safety profiles. Moreover, CAR-T-cell therapy, particularly CD19-directed products, has shown unprecedented remission rates in refractory B-ALL. The integration of targeted and immune-based therapies into conventional regimens represents a decisive step toward precision medicine, aiming to enhance survival outcomes while reducing treatment-related toxicity and improving quality of life in ALL children. This review aims to provide a comprehensive overview of the current understanding of ALL pathobiology and therapeutic approaches, with particular emphasis on the expanding role of immunotherapeutic strategies in pediatric disease. Full article

Background/Objectives: Ponatinib (PON) is a potent anticancer drug widely used to treat chronic myeloid leukemia (CML). Although many cancer survivors benefit from such therapies, managing drug-induced side effects, especially cardiotoxicity, remains a major challenge. Despite its prevalence, the exact mechanisms underlying PON-induced cardiotoxicity have not been thoroughly investigated. Additionally, the potential of Bone Morphogenetic Protein 7 (BMP-7) to alleviate these cardiotoxic effects has yet to be explored. Methods: To address these essential questions, we conducted a study using C57BL/6 mice. Mice were treated with PON (25 mg/kg cumulative dosage) or a combination of PON and BMP-7 (600 μg/kg), alongside a suitable control group. Heart function was assessed by echocardiography. Different techniques were performed to evaluate the apoptotic pathway. Histological staining was performed to investigate structural changes. Results: PON treatment increased apoptotic cell death (increased expression of BAX and caspase-3) in the heart through the PTEN/Akt signaling pathway. Further, PON treatment led to increased cardiac hypertrophy, adverse remodeling, and reduced cardiac function. Importantly, BMP-7 markedly reduced PON-induced apoptosis (increased Bcl2 expression) and its downstream effects. Conclusions: These results suggest that BMP-7 might inhibit PON-induced cardiotoxicity. Furthermore, our findings pave the way for future translational studies with BMP-7, which can demonstrate the therapeutic potential of BMP-7 in a clinical setting. Full article

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by both an abnormal expansion of the granuloblastic clone and the pathognomonic presence of the Philadelphia (Ph) chromosome that generates the BCR::ABL1 oncoprotein. Despite the surfacing of tyrosine kinase Inhibitors (TKIs) in 2001, which changed the evolution of the disease, resistance due to point mutation or compound alteration during treatment with target therapy may occur. One of the mutations that is still an on-going challenge in clinical and scientific field is the T315I mutation, since it gives patients a poor prognosis attributable to acquired resistance to therapy. In the following narrative review, we will discuss the current knowledge on the T315I mutation, explore the most suitable treatment options, examine the role of third-generation tyrosine kinase inhibitors, and outline potential future therapeutic strategies. Full article

Advanced hepatocellular carcinoma (HCC) exhibits a poor prognosis. Immunotherapy has emerged as a major player for both the upfront treatment of advanced HCC and disease progression on prior systemic therapies. In the first-line treatment of advanced HCC, immunotherapy demonstrated superior efficacy outcomes compared to tyrosine kinase inhibitors and a favourable safety profile. Initial treatment strategies of single-agent immune checkpoint inhibitors (ICIs) yielded only limited clinical activity. A deeper understanding of the hepatic tumour microenvironment and immunotolerance has driven the development of biologically relevant immunotherapy combinations. These combinations, which include antiangiogenic agents or dual ICIs targeting both PD-1/PD-L1 and CTLA-4, are the focus of current research. Recently published clinical trials involving ICI-based combination therapies achieved improved treatment outcomes, continuing to reshape the treatment paradigm for advanced HCC. While different immunotherapy combinations have shown variable efficacy in augmenting anti-tumour immunity, they inevitably increase toxicity and costs. Furthermore, the search for predictive biomarkers remains an unmet challenge in advanced HCC. In this review, we will summarise the notable advances in immunotherapy for the treatment of advanced HCC, discuss the underlying immune microenvironment and rationale for combinations, and explore opportunities for novel therapeutic targets beyond conventional immune checkpoints to overcome immunotherapy resistance. Full article

Over the past decade, chronic lymphocytic leukaemia (CLL) treatment has shifted from chemoimmunotherapy to targeted oral agents, predominantly Bruton’s tyrosine kinase inhibitors (BTKis) and the BCL-2 inhibitor venetoclax. These therapies have significantly improved outcomes and are now established as first-line treatment options. However, CLL remains incurable, and resistance or intolerance to both drug classes (double-refractory disease) is an emerging challenge. This has driven the development of novel therapeutic strategies, including non-covalent BTKis such as pirtobrutinib and nemtabrutinib, which retain activity in BTK C481-mutated disease. Next-generation BCL-2 inhibitors (sonrotoclax, lisaftoclax) and BTK degraders are promising in early clinical trials. Immunotherapeutic approaches, such as bispecific T-cell engagers, CD20/CD3 antibodies, and CAR-T cell therapies, provide additional options for high-risk patients. Although PI3K inhibitors remain under investigation, their role is yet to be defined due to safety concerns. Minimal residual disease (MRD)-guided, fixed-duration regimens represent a significant paradigm shift toward personalised treatment and potentially deeper remissions. Ongoing clinical studies are expected to introduce new effective therapies that may further transform the management of CLL in the coming years. Full article

Metastatic or unresectable pheochromocytomas and paragangliomas (PPGLs) remain rare but clinically challenging neuroendocrine neoplasms with limited curative options. Traditionally managed with surgery, radionuclide therapy, or cytotoxic chemotherapy, systemic treatments have historically achieved disease stabilization, rather than durable remissions. In recent years, however, the therapeutic landscape has evolved substantially. Radiopharmaceuticals such as ¹³¹I-MIBG and ¹⁷⁷Lu-DOTATATE continue to play a pivotal role, achieving disease control in many patients. Cytotoxic regimens, particularly temozolomide, remain relevant, with some studies suggesting that SDHB-mutated PPGLs demonstrate a heightened sensitivity associated with MGMT promoter hypermethylation and reduced MGMT expression. Targeted agents are increasingly important: multi-kinase inhibitors such as sunitinib, anlotinib, and cabozantinib have shown meaningful activity. The landmark approval of belzutifan, a HIF-2α inhibitor, in 2025 represents the first oral targeted therapy for advanced/metastatic PPGL, which is particularly relevant for pseudohypoxic Cluster 1 tumors. Immunotherapy has yielded modest responses with checkpoint inhibitor monotherapy, but ongoing studies of dual checkpoint blockade and TKI–ICI combinations hold promise. Novel approaches, including PARP inhibition, metabolic targeting strategies, and cancer vaccines, are under investigation, especially for aggressive SDHB-related disease. Optimal sequencing of these therapies is emerging as a central challenge, with treatment strategies increasingly tailored to molecular genotype, tumor behavior, and functional imaging phenotype. This review summarizes current evidence and highlights ongoing clinical trials, underscoring a paradigm shift toward precision medicine and rational combination strategies. Collectively, these advances bring cautious optimism that metastatic PPGLs may soon become a more manageable chronic disease with improved survival and quality of life. Full article