Search Results (136)

Tyrosine kinases (TKs) are drug targets in diffuse intrinsic pontine glioma (DIPG). Ion channels are emerging targets in cancer. TKIs targeting different kinases such as everolimus, crizotinib, dasatinib, erlotinib, lapatinib, perifosine and midostaurin (0.001–100 μM) were investigated on cell proliferation and ion channel currents. Methods: Cell viability assays in parallel with a patch-clamp study and Western blot of target proteins are performed in SU-DIPG-36 and SU-DIPG-50 cells. Results: Midostaurin is the most effective drug in different assays. Patch-clamp investigations show that the application of midostaurin reduced the inward and outward whole-cell cation channel currents vs. controls in the presence of low internal ATP. These currents were sensitive to the KATP channel inhibitors glibenclamide and repaglinide and were fully reduced by the unselective blocker TEA-BaCl₂. Midostaurin also reduced currents that are sensitive to TRPV1 channel blockers capsazepine and ruthenium-red. The IC₅₀ values of midostaurin as an antiproliferative drug and ion channel inhibitor in either cell line are in the sub-micromolar range. In SU-DIPG-36 cells midostaurin causes a concentration-dependent upregulation of autophagy markers. Conclusions: The inhibition of cation channel currents by midostaurin in SU-DIPG-36 and SU-DIPG-50 cells and the autophagy potentiation in SU-DIPG-36 cells can be novel mechanisms in DIPG. Full article

Objective: The development of ABCB1-mediated resistance limits the clinical efficacy of paclitaxel. Lapatinib is a small-molecule reversible tyrosine kinase and ABCB1 inhibitor that could prevent resistance. Our objective was to determine a recommended phase 2 dose (RP2D) of the combination of paclitaxel and lapatinib. Methods: A phase 1 dose-escalation study utilizing a Bayesian optimal interval (BOIN) design in recurrent ovarian cancer patients was conducted. Patients were pretreated with pulsed lapatinib in the 48 h preceding weekly paclitaxel (80 mg/m²) in 28-day cycles for up to three cycles. We evaluated three lapatinib doses, escalating from 750 to 2000 mg orally twice daily. Results: Sixteen patients were eligible and evaluable for efficacy and toxicity. Patients received a median of three prior therapies. Three patients were treated at dose level 1, six at dose level 2, and seven at dose level 3. There was one dose-limiting toxicity (DLT) in dose level 2 (diarrhea) and another in dose level 3 (neutropenia), with a posterior DLT estimate of 0.17, 95% credible interval of (0.01, 0.53) for dose level 3 based on isotonic regression. The most common grade 1–2 adverse effects were diarrhea (87.5%), leukopenia (56.3%), and anemia (50%). One (6.25%) patient had a complete response, and seven (43.75%) patients had partial responses for an overall response rate (ORR) of 50%. The clinical responses are supported by a significant decreasing trend in CA 125 over six cycles (p = 0.0001). Among the seven patients treated at the RP2D, the ORR was 71.4%. Conclusions: The combination of paclitaxel and lapatinib was safe and demonstrated an efficacy signal. The RP2D was weekly paclitaxel 80 mg/m² combined with lapatinib 2000 mg twice daily two days before the paclitaxel dose. This trial was registered at ClinicalTrials.gov ID: NCT04608409. Full article

Cancer therapy development increasingly focuses on multi-target approaches to inhibit key proteins involved in tumor growth and angiogenesis. This study explored the potential inhibitory interactions of 110 cannabinoid derivatives using molecular docking simulations against epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor-1 (VEGFR-1), and VEGFR-2. Blind docking with AutoDock Vina identified eight recurrent hits across all three targets, including polar THC glucuronides and more drug-like cannabinoid scaffolds. Among these, 2′-Hydroxy-Delta (9)-THC and Ajulemic Acid combined favorable multi-target binding with superior predicted pharmacokinetic properties compared with other cannabinoids and reference inhibitors (lapatinib, motesanib, and sorafenib). ADME predictions highlighted Ajulemic Acid as the most promising oral candidate, showing optimal molecular weight, high oral bioavailability, and good gastrointestinal absorption, while 2′-Hydroxy-Delta (9)-THC exhibited potential for central nervous system exposure due to predicted blood–brain barrier permeability. In contrast, glucuronidated THC metabolites and highly lipophilic cannabinol esters displayed strong docking scores but suboptimal drug-likeness, suggesting prodrug- or metabolite-like behavior rather than suitability as primary oral leads. Toxicity predictions classified all compounds as moderately toxic, with Ajulemic Acid showing a comparatively more favorable safety profile. These findings do not demonstrate biological inhibition and should be interpreted strictly as hypothesis-generating computational evidence, providing a rational framework for future in vivo and in vitro validations. Full article

Background: Resistance to HER2-targeted therapies remains a major limitation in the treatment of HER2-positive breast cancer, where disease progression inevitably occurs in advanced stages. Development of next-generation strategies that retain activity in resistant disease is therefore a critical priority. Disitamab vedotin (RC48) is a novel antibody–drug conjugate (ADC) targeting HER2 that couples a humanized anti-HER2 antibody to the potent microtubule-disrupting agent monomethyl auristatin E. Methods: We compared the activity and mechanism of action of RC48 with that of trastuzumab emtansine (T-DM1) across HER2-positive and HER2-low cellular models, including multiple sublines resistant to current HER2-targeted agents. Results: In HER2-overexpressing breast cancer cell lines, RC48 consistently demonstrated superior antiproliferative effect with respect to T-DM1. Treatment with RC48 induced G2/M arrest and apoptotic cell death, associated with increased pHistone-H3 and cyclin B1 and downregulation of Wee1, consistent with blockade of cell cycle progression in mitosis. Although RC48 and T-DM1 internalized similarly, RC48 displayed more efficient intracellular payload release, providing a mechanistic explanation for its enhanced efficacy. Notably, RC48 retained strong activity in BT474-derived sublines resistant to T-DM1, lapatinib, or neratinib, inducing cell cycle arrest, apoptosis, and caspase activation in all resistant models. In contrast, T-DM1 exhibited only partial effects in resistant cells and was completely ineffective in a T-DM1-refractory clone. Conclusions: Together, these findings identify disitamab vedotin as a potent next-generation HER2-targeting ADC with the unique capacity to overcome acquired resistance to HER2-directed therapies. RC48 represents a promising therapeutic strategy for patients with refractory HER2-positive breast cancer and warrants further clinical investigation. Full article

Background: Canine mammary carcinoma (CMC) is the most common malignant tumour in female dogs and, due to its similarities, is a valuable comparative model for human breast cancer. Kinase inhibitors have revolutionised the treatment of human breast cancer; their use in veterinary oncology remains marginal. Aim: This review summarises the current knowledge of kinase signalling pathways in CMC and assesses which kinase inhibitors approved for human use have potential in veterinary medicine. Methods: A systematic search of the PubMed database from 1985 to 2025 was performed, focusing on kinase-targeted therapies in both human and canine mammary carcinomas. Data were categorised according to molecular target, clinical approval status, and available preclinical or clinical veterinary evidence. Results: Key molecular pathways targeted by kinase inhibitors are conserved across species, supporting translational opportunities. In vitro studies demonstrate that palbociclib, alpelisib, everolimus, and lapatinib inhibit growth and signalling in CMC cell lines. Clinical trials have not been conducted. Conclusions: Approved kinase inhibitors for human use have untapped therapeutic potential in veterinary oncology. Translational research, including xenograft and organoid models, followed by clinical trials in dogs, is required. Gaining this knowledge could lead to targeted treatment for dogs while advancing comparative understanding of mammary cancer biology across species. Full article

Background: Medullary thyroid carcinoma is a rare neuroendocrine tumor with limited therapeutic options, as current kinase inhibitors are often associated with significant toxicity and drug resistance. This study aimed to explore novel treatment strategies by testing targeted agents alone and in combination. Methods: Human medullary thyroid carcinoma TT cells with RET mutations were treated with Sorafenib, Lapatinib, and Bevacizumab. Cell proliferation was monitored in real time using the xCELLigence system, and apoptosis was assessed by flow cytometry. Results: Sorafenib and Lapatinib each showed strong, dose-dependent cytotoxic effects, with Lapatinib demonstrating the greatest potency. Bevacizumab alone exhibited minimal cytotoxic activity, but when combined with Sorafenib or Lapatinib it significantly enhanced their effects, even at concentrations that were only partially effective individually. The Lapatinib–Bevacizumab combination produced the most potent inhibition of cell viability, comparable to high-dose monotherapy. Conclusions: These findings suggest that combining kinase inhibitors with Bevacizumab may enhance antitumor activity, allow the use of lower drug doses, and overcome resistance, representing a promising therapeutic strategy for medullary thyroid carcinoma that warrants further investigation in clinical settings. Full article

Background: The mitogen-activated protein kinase (MAPK) signaling pathway is frequently dysregulated in cutaneous squamous cell carcinoma (cSCC). Tumor progression locus 2 (Tpl2), a serine/threonine protein kinase within the MAPK family, regulates cellular proliferation, survival, and inflammatory responses. Loss of Tpl2 activates compensatory signaling cascades, driving increased papilloma and cSCC development. In this study we examined whether dysregulated ErbB signaling contributes to the enhanced tumor burden found in Tpl2^−/− mice. Methods: To evaluate whether aberrant ErbB signaling drives tumorigenesis in Tpl2^−/− mice, wild-type (Tpl2^+/+) and Tpl2^−/− mice were subjected to a two-stage chemical carcinogenesis protocol for 48 weeks. A subset of mice received Gefitinib (an EGFR inhibitor) or Lapatinib (a HER2 inhibitor) in their diet. Results: We found that Tpl2 ablation increases gene expression of EGFR, HER2, and HER3, while baseline protein levels remain unchanged between Tpl2 genotypes. To investigate the possibility of microRNA (miR)-mediated post-transcriptional regulation of EGFR, HER2, and HER3, we measured ErbB-related miR expression in keratinocytes. We found that HER2/3-related miRs 205 and 21 are increased in Tpl2^−/− keratinocytes. Further, Tpl2 loss enhances p-EGFR, EGFR, and HER2 protein expression in papillomas. and HER2-related microRNAs (miRs) 205 and 21 in keratinocytes, and enhances p-EGFR, EGFR, and HER2 protein expression in papillomas. Tpl2^−/− mice developed 12-fold more papillomas and 4-fold more cSCCs compared to Tpl2^+/+ animals. Treatment with Gefitinib or Lapatinib reduced papilloma numbers by 88% and 50%, respectively, while restoring cSCC numbers to Tpl2^+/+ levels. Conclusions: These findings indicate that ErbB targeting represents a promising therapeutic strategy for cSCCs arising from MAPK pathway dysregulation. Full article

Lapatinib is an approved therapeutic agent for the treatment of HER2-positive breast cancer. It has a high affinity for the non-receptor cytoplasmic tyrosine kinases of the EGFR and HER2 receptors. It is a type II inhibitor, with K_i^app values of 3 nM and 13 nM, respectively. The dissociation rate of the lapatinib–receptor complex is notably slow compared with many other kinase inhibitors. Although the literature contains numerous reports on radiolabelled ligands for HER-family receptors, studies on radiolabelled tyrosine kinase inhibitors are far fewer, and only few focus specifically on radiolabelled lapatinib. The aim of this review is to compile and discuss the chemical and biological data on lapatinib-based radiopharmaceuticals with potential applications in the diagnosis and treatment of HER2-positive tumours. Full article

Background/Objectives: The dual targeting of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) represents an effective approach for cancer treatment. The current study involved the design, synthesis, and biological evaluation of a new series of purine-containing hydrazones, 6–24 (a,b), as anticancer agents targeting EGFR and HER2 kinases. Methods: The proposed compounds were initially screened in silico using molecular docking to investigate their binding affinity to the active sites of EGFR and HER2 kinase domains. Subsequently, the compounds were synthesized and evaluated in vitro for their antiproliferative activity, using the MTT assay, against the various cancer cell lines A549, SKOV-3, A2780, and SKBR-3, with lapatinib as the reference drug. The most active derivatives were then examined to determine their inhibitory activity against EGFR and HER2 kinases. Results: Among the assessed compounds, significant antiproliferative activity was demonstrated by 19a, 16b, and 22b. 19a exhibited substantial anticancer efficacy against A549 and SKBR-3, with IC₅₀ values of 0.81 µM and 1.41 µM, respectively. This activity surpassed lapatinib, which has an IC₅₀ of 11.57 µM on A549 and 8.54 µM on SKBR-3 cells. Furthermore, 19a, 16b, and 22b exhibited superior EGFR inhibitory efficacy compared with lapatinib (IC₅₀ = 0.13 µM), with IC₅₀ values of 0.08, 0.06, and 0.07 µM, respectively. Regarding HER2, 22b demonstrated the greatest potency with an IC₅₀ of 0.03 µM, equipotent to lapatinib (IC₅₀ = 0.03 µM). Flow cytometry analysis of A549 cells treated with 19a and 22b indicated their ability to arrest the cell cycle during the G1 phase and to trigger cellular apoptosis. Conclusions: Compounds 19a, 16b, and 22b represent intriguing candidates for the development of an anticancer agent targeting EGFR and HER2 kinases. Full article

We previously reported that the level of EGFR expression is directly associated with the survival rate of estrogen receptor-positive (ER+) breast cancer patients. Here, we investigated how ER activation by 17β-estradiol (E2), the most potent form of estrogen, affects the expression or activity of EGFR or EGFR-related genes in ER+ breast cancer cells. As expected, E2 enhanced cell proliferation, the induction of S phase, and tumor growth in ER+ breast cancer models. E2 also increased the expression of secretory proteins, including amphiregulin (AREG), angiogenin, artemin, and CXCL16. We focused on AREG, which is a ligand of the epidermal growth factor receptor (EGFR). The levels of AREG expression were positively correlated with ESR1 expression. Our results also showed higher AREG mRNA expression levels in ER+ breast cancer cells than in ER- breast cancer cells. We treated ER+ breast cancer cells with lapatinib to inhibit the AREG/EGFR signaling pathway and then completely inhibited E2-induced cell proliferation and S-phase induction. Similar to the lapatinib treatment, cell proliferation, S-phase induction, cell migration, and tumor growth were suppressed by AREG knockdown. Taken together, we demonstrated that the induction of AREG by E2 contributes to EGFR activation, which then affects cell proliferation and tumor growth. Therefore, we suggest that AREG acts as an intermediary between EGFR and ER and targeting both ERs and EGFRs through combination therapy could prevent tumor progression in EGFR+ ER+ breast cancer patients. Full article

Resistance to HER2 tyrosine-kinase inhibitor Lapatinib (Lap) is one of the leading causes of cancer treatment failure in HER2+ breast cancer (BC), associated with an aggressive tumor phenotype. Cryptotanshinone (Cry) is a natural terpene molecule that could function as a chemosensitizer by disturbing estrogen receptor (ERα) signaling and inhibiting the protein translation factor-4A, eIF4A. Therefore, we evaluated Cry dual regulation on eIF4A and ERα. This study aimed to elucidate the underlying mechanisms of Lap chemoresistance and the impact of Cry on them. We generated two Lap-resistant BT474 cell HER2+ variants named BT474^LapRV1 and BT474^LapRV2 with high chemoresistance levels, with 7- and 11-fold increases in EC₅₀, respectively, compared to BT474 parental cells. We found a PDCD4-p70S6Kβ axis association with Lap chemoresistance. However, a concomitant down-regulation of the RAF-MEK-ERK cell survival pathway and NF-κB was found in the chemoresistant cell variants; this phenomenon was exacerbated by joint treatment of Cry and Lap under a Lap plasmatic reported concentration. Optimized calcium management was identified as a compensatory mechanism contributing to chemoresistance, as determined by the higher expression of calcium pumps PMCA1/4 and SERCA2. Contrary to expectations, a combination of Lap and Cry did not affect the chemoresistance despite the ERα down-regulation; Cry-eIF4A binding possibly dampens this condition. Results indicated the pro-survival eIF4A/STAT/Bcl-xl pathway and that the down-regulation of the MAPK-NF-κB might function as an adaptive mechanism; this response may be compensated by calcium homeostasis in chemoresistance, highlighting new adaptations in HER2+ cells that lead to chemoresistance. Full article

Background: Acute myeloid leukemia (AML), a malignant blood disease, is caused by the excessive growth of undifferentiated myeloid cells, which disrupt normal hematopoiesis and may invade several organs. Given the high heterogeneity in prognosis, identifying stable prognostic biomarkers is crucial for improved risk stratification and personalized treatment strategies. Although glycolysis has been extensively studied in cancer, its prognostic significance in AML remains unclear. Methods: Glycolysis-related prognostic genes were identified by differential expression profiles. We modeled prognostic risk by least absolute shrinkage and selection operator (LASSO) regression and validated it by Kaplan–Meier (KM) survival analysis, receiver operating characteristic (ROC) curves, and independent datasets (BeatAML2.0, GSE37642, GSE71014). Mechanisms were further explored through immune microenvironment analysis and drug sensitivity scores. Results: Differential expression and survival correlation analysis across the genes associated with glycolysis revealed multiple glycolytic genes associated with the outcomes of AML. We constructed a seven-gene prognostic model (G6PD, TFF3, GALM, SOD1, NT5E, CTH, FUT8). Kaplan–Meier analysis demonstrated significantly reduced survival in high-risk patients (hazard ratio (HR) = 3.4, p < 0.01). The model predicted the 1-, 3-, and 5-year survival outcomes, achieving area under the curve (AUC) values greater than 0.8. Immune profiling indicated distinct cellular compositions between risk groups: high-risk patients exhibited elevated monocytes and neutrophils but reduced Th1 cell infiltration. Drug sensitivity analysis showed that high-risk patients exhibited resistance to crizotinib and lapatinib but were more sensitive to motesanib. Conclusions: We established a novel glycolysis-related gene signature for AML prognosis, enabling effective risk classification. Combined with immune microenvironment analysis and drug sensitivity analysis, we screened metabolic characteristics and identified an immune signature to provide deeper insight into AML. Our findings may assist in identifying new therapeutic targets and more effective personalized treatment regimes. Full article

Current antiviral treatments often target specific viral components, which can lead to the rapid emergence of drug-resistant mutants. Targeting host signaling pathways, including their associated cellular factors, that are important for virus replication is a novel approach toward the development of next-generation antivirals to overcome drug resistance. Various cellular receptor tyrosine kinases (RTKs) have previously been shown to play important roles in mediating viral replication including coronaviruses. In this study, we examined the roles of RTKs in SARS-CoV-2 replication in two cell lines, A549-ACE2 (human lung epithelial cells) and Vero-E6 (African Green Monkey kidney cell), via chemical inhibitors. We showed that the HER2 inhibitor Lapatinib significantly reduced viral replication in both cell lines, the TrkA inhibitor GW441756 was effective only in A549-ACE2 cells, while the EGFR inhibitor Gefitinib had little effect in either cell line. Lapatinib and GW441756 exhibited a high therapeutic index (CC₅₀/EC₅₀ > 10) in A549-ACE2 cells. Time-of-addition experiments indicated that Lapatinib may inhibit the early entry step, whereas GW441756 can affect post-entry steps of the viral life cycle. These findings suggest the important roles of HER2 and TrkA signaling in SARS-CoV-2 infection in human lung epithelial cells and support further investigation of RTK inhibitors as potential COVID-19 treatments. Full article

Background/Objective: Cancer is the leading cause of death worldwide despite the diversity of antitumor therapies, which highlights the necessity to explore new anticancer agents. Methods: We synthesized 5,5-diphenylhydantoin derivatives including Schiff’s bases 7–27 and evaluated their cytotoxicity via the MTT assay. Enzymatic inhibition assays, cell cycle and apoptosis analyses, and molecular docking studies were also conducted. Results: Derivative 24 demonstrated the highest cytotoxic activity, with IC₅₀ values of 12.83 ± 0.9 μM, 9.07 ± 0.8 μM, and 4.92 ± 0.3 μM against the cell lines HCT-116, HePG-2, and MCF-7, respectively. Compounds 10, 13, and 21 showed potent antitumor activities versus the examined cell lines (average IC₅₀ = 13.2, 14.5, and 13.1 μM), respectively; moreover, these compounds also demonstrated promising EGFR and HER2 inhibitory activities, with IC₅₀ values in the range 0.28–1.61 µM. Derivative 24 displayed the highest EGFR and HER2 inhibitory activity values (IC₅₀ = 0.07 and 0.04 µM), respectively, which were close to those of the reference drugs erlotinib and lapatinib. Therefore, compound 24 was selected for further examinations and exhibited an inducing effect on apoptosis via diminishing the anti-apoptotic protein levels of BCL-2 (8.598 ± 0.29 ng/mL) and MCL-1 (261.20 ± 8.97 pg/mL) and promoting cell cycle arrest at the G2/M phase (33.46%). The binding relationships between compound 24 and the active sites of EGFR and HER2, which are similar to the co-crystallized inhibitors, were investigated using a molecular docking approach. Conclusions: These findings provide insights into the potential anticancer activities of the synthesized derivatives for further optimization to achieve therapeutic use. Full article

Breast cancer (BC) remains a significant global health challenge due to its complex biology, which complicates both diagnosis and treatment. Immunotherapy and cancer vaccines have emerged as promising alternatives, harnessing the body’s immune system to precisely target and eliminate cancer cells. However, several key factors influence the selection and effectiveness of these therapies, including BC subtype, tumor mutational burden (TMB), tumor-infiltrating lymphocytes (TILs), PD-L1 expression, HER2 resistance, and the tumor microenvironment (TME). BC subtypes play a critical role in shaping treatment responses. Triple-negative breast cancer (TNBC) exhibits the highest sensitivity to immunotherapy, while HER2-positive and hormone receptor-positive (HR+) subtypes often require combination strategies for optimal outcomes. High TMB enhances immune responses by generating neoantigens, making tumors more susceptible to immune checkpoint inhibitors (ICIs); whereas, low TMB may indicate resistance. Similarly, elevated TIL levels are associated with better immunotherapy efficacy, while PD-L1 expression serves as a key predictor of checkpoint inhibitor success. Meanwhile, HER2 resistance and an immunosuppressive TME contribute to immune evasion, highlighting the need for multi-faceted treatment approaches. Current breast cancer immunotherapies encompass a range of targeted treatments. HER2-directed therapies, such as trastuzumab and pertuzumab, block HER2 dimerization and enhance antibody-dependent cellular cytotoxicity (ADCC), while small-molecule inhibitors, like lapatinib and tucatinib, suppress HER2 signaling to curb tumor growth. Antibody–drug conjugates (ADCs) improve tumor targeting by coupling monoclonal antibodies with cytotoxic agents, minimizing off-target effects. Meanwhile, ICIs, including pembrolizumab, restore T-cell function, and CAR-macrophage (CAR-M) therapy leverages macrophages to reshape the TME and overcome immunotherapy resistance. While immunotherapy, particularly in TNBC, has demonstrated promise by eliciting durable immune responses, its efficacy varies across subtypes. Challenges such as immune-related adverse events, resistance mechanisms, high costs, and delayed responses remain barriers to widespread success. Breast cancer vaccines—including protein-based, whole-cell, mRNA, dendritic cell, and epitope-based vaccines—aim to stimulate tumor-specific immunity. Though clinical success has been limited, ongoing research is refining vaccine formulations, integrating combination therapies, and identifying biomarkers for improved patient stratification. Future advancements in BC treatment will depend on optimizing immunotherapy through biomarker-driven approaches, addressing tumor heterogeneity, and developing innovative combination therapies to overcome resistance. By leveraging these strategies, researchers aim to enhance treatment efficacy and ultimately improve patient outcomes. Full article