Search Results (83)

Background and Objectives: TAM receptors—Tyro3, Axl, and Mer—and their ligand Growth Arrest-Specific 6 (Gas6) represent a pleiotropic system implicated in fibrosis. Increased Gas6 and Axl expression have previously been observed in lung samples and fibroblast cultures from Idiopathic Pulmonary Fibrosis (IPF) patients. The study explored the contribution of Gas6/TAM system in fibrosis development and the impact of its pharmacological inhibition in fibroblasts. Materials and Methods: IPF fibroblasts (IPF FBs) and control human pulmonary fibroblasts (HPFs) were treated with R428 (Axl-specific inhibitor), LDC1267 (TAM inhibitor), or Nintedanib (an IPF-approved drug) to evaluate the influence of these drugs on cell proliferation, migration, and the expression of pro-inflammatory and pro-fibrotic genes. Fibroblast-to-myofibroblast differentiation was induced by TGF-β. The impact of IPF FBs and HPF on macrophage polarization was investigated through a co-culture of fibroblasts with monocyte-derived macrophages, with the further gene expression analysis of markers of the M1 (pro-inflammatory) or M2 (pro-fibrotic) polarization forms. Results: Cell proliferation was monitored in fibroblasts treated with TGF-β, the drugs, and their combination. In the presence of LDC1267 and Nintedanib, minor differences in cell confluence were detected between IPF FBs and HPFs; R428 (1 μM) seemed to have a higher inhibitory impact on IPF FBs. Regarding cell migration, the fibroblasts treated with LDC1267 exhibited slower wound closure. R428 treatment led to a relative wound closure of 76% in HPFs but only 56% in IPF FBs (60 h). R428 (1 μM) significantly reduced the expression of the pro-fibrotic markers ACTA2, COL1A1, and FN1 in HPFs and IPF FBs compared to TGF-β treatment. HPFs and IPF FBs co-cultured with monocyte-derived macrophages demonstrated a significantly increased expression of MRC1 while the expression of FN1, TNFα, and CXCL10 was moderately increased. Conclusions: These findings suggest that R428 and LDC1267 modulate the proliferation, migration, and gene expression of activated fibroblasts via TAM signaling. Fibroblast-mediated effects on macrophage polarization underscore the relevance of intercellular crosstalk in fibrotic disease. Full article

The mesenchymal–epithelial transition/plasticity (MET/EMP) axis is a key regulator of tumor development, cancer progression, and resistance to therapy, making it an attractive target for intervention. This review highlights strategies to modulate MET/EMP using three representative agents—capmatinib, bemcentinib, and galunisertib—each acting on distinct signaling pathways. Capmatinib is a selective MET tyrosine kinase inhibitor with notable efficacy in non-small cell lung cancer harboring MET exon 14 skipping mutations. Bemcentinib blocks AXL receptor tyrosine kinase, interfering with AXL/GAS6 signaling that promotes tumor survival, metastasis, and therapeutic resistance. Galunisertib inhibits TGF-β signaling, reducing epithelial–mesenchymal transition (EMT), immune evasion, and metastatic potential. We discuss their mechanisms of action, therapeutic applications, and current clinical progress. Although these targeted therapies show potential to overcome resistance and improve patient outcomes, challenges remain due to the complex regulation of EMP. Future directions focus on refining combination strategies and advancing personalized approaches to enhance efficacy across multiple cancer types. Full article

AXL, a receptor tyrosine kinase, has emerged as a promising therapeutic target in triple-negative breast cancer (TNBC) due to its critical roles in tumor progression, metastasis, and immune evasion. In this study, we investigated the antitumor efficacy and immunomodulatory potential of AB-329, a selective AXL kinase inhibitor, in preclinical models of TNBC. Transcriptome analysis and single-cell RNA sequencing datasets revealed elevated AXL expression in mesenchymal TNBC subtypes and a negative association with immune cell infiltration. While AB-329 demonstrated moderate antiproliferative effects as a monotherapy, its combination with paclitaxel led to substantially enhanced antiproliferative and anti-metastatic effects compared to gemcitabine, DXd, and SN-38. In murine TNBC allograft models, the combination of AB-329 and paclitaxel significantly reduced tumor growth, and AB-329 increased activated natural killer (NK) cell infiltration in humanized mouse models. Analysis of human breast cancer tissue further confirmed that low AXL expression is associated with a higher presence of NK cells in the tumor. These findings suggest that AB-329 not only augments chemotherapy efficacy but also reshapes the tumor immune microenvironment, supporting its further development as a dual-action therapeutic strategy for AXL-positive TNBC. Full article

Background/Objectives: Intrinsic radioresistance in non-small-cell lung cancer (NSCLC) is partially driven by adaptive redox mechanisms that prevent oxidative cell death. Ferroptosis, an iron-dependent form of regulated cell death characterized by lipid peroxidation, has emerged as a potential therapeutic vulnerability in tumors with elevated antioxidant capacity. However, its mechanistic integration with radiotherapy remains incompletely understood. Methods: We compared the effects of three clinically approved VEGFR-targeting tyrosine kinase inhibitors (TKIs), cabozantinib, lenvatinib, and ripretinib, on NSCLC cell viability with and without radiation. Subsequent mechanistic studies focused on cabozantinib and included ferroptosis rescue assays (ferrostatin-1, deferoxamine), lipid ROS quantification, glutathione assays, clonogenic survival, co-immunoprecipitation of BECN1–SLC7A11 complexes, and BECN1 knockdown by siRNA and shRNA. Results: All three TKIs were evaluated for cytotoxicity, but only cabozantinib significantly reduced NSCLC cell viability in combination with radiation in a ferroptosis-dependent manner. Cabozantinib inhibited STAT3 phosphorylation and downregulated MCL1, resulting in the release of BECN1. This allowed BECN1 to bind and suppress SLC7A11, disrupting system Xc⁻ function, depleting glutathione, and promoting lipid ROS accumulation. Genetic silencing of BECN1 reversed these effects and restored redox balance and clonogenic capacity. Lenvatinib and ripretinib failed to elicit similar responses, indicating that the inhibition of non-VEGFR targets (e.g., MET, AXL) may be essential for ferroptosis induction by cabozantinib. Conclusions: Cabozantinib enhances the radiosensitization of NSCLC cells through ferroptosis induction mediated by the suppression of the STAT3/MCL1/BECN1/SLC7A11 axis. These findings uncover a novel mechanism linking kinase inhibition to redox imbalance and suggest that the pharmacologic modulation of ferroptosis using multi-target TKIs may represent a rational approach to overcome radioresistance in NSCLC. Full article

Preeclampsia (PE) is a leading cause of maternal and fetal morbidity that affects 2–8% of pregnancies worldwide, driven by placental dysfunction and systemic inflammation. Growth arrest-specific protein 6 (Gas6) and its receptor AXL play pivotal roles in PE pathogenesis, promoting trophoblast impairment and vascular dysregulation. This study investigated the transcriptomic reversal effects of AXL Receptor Tyrosine Kinase (AXL) inhibition in a Gas6-induced rat model of PE using RNA sequencing (RNA-seq). Pregnant rats were administered Gas6 to induce PE-like symptoms such as hypertension and proteinuria; a subset also received the AXL inhibitor R428. RNA-seq of placental tissues revealed 2331 differentially expressed genes (DEGs) in Gas6-AXLi versus Gas6 (1277 upregulated, 1054 downregulated). Protein–protein interaction networks and Gene Ontology enrichment highlighted upregulated mitochondrial functions, including electron transport chain components (e.g., NDUFC2, COX5A), suggesting enhanced energy metabolism. In the secondary analysis that compared Gas6 to Control, Gas6-upregulated extracellular matrix proteins (e.g., COL4A1, LAMC1) linked to fibrosis were reversed by AXL inhibition, indicating ameliorated placental remodeling. AXL inhibition activated compensatory pathways beyond Gas6 blockade, unveiling novel mechanisms for PE resolution. These findings position AXL inhibitors as promising therapeutics, offering insights into mitochondrial and fibrotic targets to mitigate this enigmatic disorder. Full article

Background/Objectives: Different risk factors are involved in the initiation and progression of melanoma. In particular, genetic and epigenetic pathways are involved in all stages of melanoma and are exploited in therapeutic approaches. This study investigated the role of circular RNA circ_0001591 in melanoma cell migration. Methods: Three different melanoma cell lines were transfected with siRNA targeting circ_0001591 and with mimic or inhibitor molecules for miR-20a-3p and miR-34a-5p. Gene and protein expression levels were analyzed by RT-qPCR and Western blot, respectively. Dual luciferase reporter assays were performed to confirm the direct interaction of miR-20a-3p and miR-34a-5p with circ_0001591, as well as with the 3’UTRs of AXL (for both miRNAs) and FOSL1 (miR-34a-5p only). Wound healing assays were conducted to assess cell migration velocity. Results: The silencing of circ_0001591 significantly reduces the migration ability of melanoma cell lines. This downregulation was associated with an increased expression of miR-20a-3p and miR-34a-5p. Dual luciferase reporter assays confirmed the direct binding of both miRNAs to circ_0001591, supporting its role as a molecular sponge. The same assays also verified that miR-20a-3p directly targets the 3’UTR of AXL, while miR-34a-5p binds the 3’UTRs of both AXL and FOSL1. Western blot analysis showed that the modulation of this axis affects the expression levels of the AXL and FRA1 oncoproteins. Conclusions: Our findings demonstrate that circ_0001591 promotes melanoma migration by sponging miR-20a-3p and miR-34a-5p, thereby indirectly modulating the expression of AXL and FRA1 oncoprotein. Further investigations of this new regulatory network are needed to better understand its role in melanoma progression and to support the development of targeted therapies. Full article

Human topoisomerase III beta (hTOP3B) is a unique and important enzyme in human cells that plays a role in maintaining genome stability, affecting cellular aging, and potentially impacting viral replication. Its dual activity on both DNA and RNA makes it a valuable target for therapeutic interventions. hTOP3B has been shown to be required for the efficient replication of certain positive-sense ssRNA viruses including Dengue. We performed in silico screening of a library comprising drugs that are FDA-approved or undergoing clinical trials as potential drugs to identify potential inhibitors of hTOP3B. The topoisomerase activity assay of the identified virtual hits showed that bemcentinib, a compound known to target the AXL receptor tyrosine kinase, can inhibit hTOP3B relaxation activity. This is the first small molecule shown to inhibit the complete catalytic cycle of hTOP3B for the potential interference of the function of hTOP3B in antiviral application. Additional small molecules that share the N⁵,N³-1H-1,2,4-triazole-3,5-diamine moiety of bemcentinib were synthesized and tested for the inhibition of hTOP3B relaxation activity. Five compounds with comparable IC₅₀ to that of bemcentinib for the inhibition of hTOP3B were identified. These results suggest that the exploration of tyrosine kinase inhibitors and their analogs may allow the identification of novel potential topoisomerase inhibitors. Full article

Background/Objectives: Ruptured abdominal aortic aneurysm (RAAA) remains a leading cause of vascular death, with mortality rates approaching 90%. Biomarkers capable of identifying the most at-risk population are urgently needed in the clinic. We aimed to identify potential alterations in the urine proteome that can enable non-invasive detection of abdominal aortic aneurysms (AAA) at high risk of rupture. Methods: We used multiplexed kinase inhibitor beads (MIBs) and quantitative mass spectrometry (MIB/MS) to examine potential biomarkers in urine samples. Quantitative proteomic profiling was conducted using iTRAQ labeling and LC-TEMPO MALDI-TOF/TOF analysis, revealing several dysregulated proteins in the urinary proteome between the two groups. MS and MS/MS data were generated using MALDI TOF/TOF instruments (models 5800 or 4800; AB SCIEX). MS/MS spectra were processed with ProteinPilot™ software version 3.0 (AB SCIEX) and matched against the UniProt/Swiss-Prot database for identification of proteins with an Unused ProtScore >1.3. Statistical tests were performed using R/Bioconductor software and bioinformatics analysis using open-source software. Results: We quantitatively measured activity over 130 kinases from various kinase families using MIB/MS with a threshold of 1.5-fold change in expression. Statistical analysis assigned significance to EPHB6, AXL, EPHB4, DDR1, EPHA2 and EPHB3. All were tyrosine kinases, and the Ephrin receptor type was dominant. The reduced expression of specific kinases identified by MIB/MS analysis was validated by Western blot. Conclusions: This pilot study presents a promising breakthrough in the diagnosis and surveillance of AAA. We identified six dysregulated tyrosine kinases in the urine proteome of patients with RAAAs, suggesting their potential as urinary biomarkers for early detection of AAA at high risk of rupture. However, these preliminary findings require confirmation in larger, prospective cohorts to validate their diagnostic utility and generalizability. Full article

The Ras/PI3K/ERK signaling network is frequently mutated and overactivated in various human cancers. Focal adhesion kinase (FAK) is commonly overexpressed in several cancer types and has been implicated in treatment resistance mechanisms. A positive feedback loop between Ras, PI3K, the cytoskeleton, and FAK was previously shown to drive Ras signaling excitability. In this study, we investigated the effectiveness of targeting Ras signaling excitability by concurrently inhibiting FAK and PI3K in cervical and pancreatic cancer cells, which depend on activation Ras/PI3K signaling. We found that the combination of FAK and PI3K inhibitors synergistically suppressed the growth of cervical and pancreatic cancer cell lines through increased apoptosis and decreased mitosis. PI3K inhibitors alone caused only a transient suppression of downstream AKT activity and paradoxically increased FAK signaling in cancer cells. The addition of an FAK inhibitor effectively counteracted this PI3K-inhibitor-induced FAK activation. Furthermore, PI3K inhibitors were found to activate multiple receptor tyrosine kinases (RTKs), including insulin receptor, IGF-1R, EGFR, HER2, HER3, AXL, and EphA2. Taken together, our results suggest that FAK inhibition is necessary to counteract the compensatory RTK activation induced by PI3K inhibitors, thereby achieving more effective suppression of cancer cell growth. These findings highlight the therapeutic potential of combined FAK and PI3K inhibition in cancer treatment. Full article

Neovascularization is an important process in brain tumor development, invasion and metastasis. Several research studies have indicated that the VEGF signaling target has potential for reducing angiogenesis in brain tumors. However, targeting VEGF signaling has not met the expected efficacy, despite initial enthusiasm. This is partly because tumors cleverly use alternative growth factor pathways, other than VEGF signaling, to restore angiogenesis. Multi-target inhibitors have been developed to inhibit several receptor kinases that play a role in the development of angiogenesis. By simultaneously affecting various receptor kinases, these treatments can potentially obstruct various angiogenic pathways that are involved in brain cancer advancement, often offering a more holistic strategy than treatments focusing on just one kinase. Since 2009, the FDA has approved a number of multi-kinase inhibitors that target angiogenic growth factor receptors (e.g., VEGFR, PDGFR, FGFR, RET, c-KIT, MET, AXL and others) for treatment of malignant diseases, including brain cancer. Here, we present some recent results from the literature regarding the preclinical and clinical effects of these inhibitors on brain tumors. Full article

Preeclampsia (PE) is a complex pregnancy-specific disorder characterized by hypertension, proteinuria, and systemic inflammation, posing significant risks to maternal and fetal health. This study investigates the role of growth arrest-specific protein 6 (Gas6) in PE pathogenesis using a rat model. Gas6 administration induces hallmark PE features, including hypertension, proteinuria, and significant alterations in placental gene expression. Transcriptomic analysis revealed changes in pathways related to extracellular matrix remodeling, interleukin signaling, and oxidative stress, highlighting their contribution to PE pathology. Key findings include the upregulation of Fam111a, linked to oxidative stress and DNA replication, and the downregulation of Clca4, associated with ion transport and cellular homeostasis. Protein-level validation through immunofluorescence confirmed these alterations, reinforcing their mechanistic roles in placental dysfunction. Enrichment analysis further identified significant disruptions in extracellular matrix organization and intercellular signaling. These results underscore the pivotal role of Gas6 in exacerbating placental oxidative stress and systemic inflammation. Importantly, therapeutic inhibition of the Gas6/AXL axis using small-molecule inhibitors mitigated PE-like symptoms, highlighting its potential as a therapeutic target. This study provides novel insights into the molecular underpinnings of Gas6-mediated placental dysfunction and supports the development of targeted therapies to improve PE outcomes. Full article

Background/Objectives: KRAS-mutated NSCLC has been targeted using monoclonal antibody (mAb) or tyrosine kinase inhibitor (TKI) therapies. However, in time, these mutations appear to develop resistance against the targeted antibodies and TKI treatments. One possible explanation is the activation of pro apoptotic pathways through the AXL–SRC–Akt axis. In this study, we identify AXL as the bypass resistant gene and investigate its role with KRAS and SRC activity. Methods: In this study, we use Dasatinib and SGI-7079 to co-inhibit SRC and AXL respectively. In vitro studies were conducted using four cell lines, and AXL suppression was achieved using siRNA and in CRISPR-Cas9 mediated knockout models. Subsequently, we studied gene-protein expression analysis using Western blot, apoptotic markers using a cytochrome release assay and cytotoxicity using an MTT assay. A549 xenografts were studied for in vivo validation of our proposed hypothesis. Results: The results suggest that dual inhibition of AXL and SRC significantly reversed this resistance, both in in vivo and in vitro studies. Conclusions: Co-inhibition of AXL and SRC synergistically reduced KRAS activity and induced apoptosis in NSCLC. Full article

Renal cell carcinoma (RCC) has diverse pathological subtypes, most of which have a poor prognosis. Patients with advanced RCC require systemic therapies for disease control. Although targeted therapies and immune checkpoint inhibitors have shown therapeutic efficacy, patients eventually succumb to disease progression. Therefore, additional therapies targeting different pathways are needed to provide more therapeutic options for sequential treatment. Our study explored the biological mechanisms and therapeutic outcomes for NPS-1034, a dual MET/AXL inhibitor, in RCC, both in vivo and in vitro. Our results showed that NPS-1034 can significantly inhibit tumor proliferation and induce cancer cell apoptosis. Besides MET and AXL, known targets of NPS-1034, we identified TNFRSF1A as another target gene inhibited by NPS-1034 via antibody arrays. This was further supported by next-generation sequencing, showing that the TNF signaling pathway is one of the most significant NPS-1034-regulated pathways. Furthermore, one of the identified target genes, GADD45A, responsible for NPS-1034 anticancer properties, was significantly associated with patient survival in RCC. GADD45A expression was significantly upregulated via NPS-1034 and downregulated via TNFRSF1A overexpression. Finally, its therapeutic efficacy was demonstrated in vivo, showing that NPS-1034 significantly alleviated the tumor burden and inhibited cell proliferation in a lung metastatic animal model. In conclusion, we explored the therapeutic mechanism of NPS-1034 and found that it targets not only MET and AXL but also TNFRSF1A. In a lung metastatic animal model, we confirmed that NPS-1034 is a potential candidate for systemic therapy in RCC. Full article

Pancreatic ductal adenocarcinoma (PDAC) poses a significant challenge in terms of diagnosis and treatment, with limited therapeutic options and a poor prognosis. This study explored the potential therapeutic role of NPS-1034, a kinase inhibitor targeting MET and AXL, in PDAC. The investigation included monotherapy with NPS-1034 and its combination with the commonly prescribed chemotherapy agents, fluorouracil and oxaliplatin. Our study revealed that NPS-1034 induces cell death and reduces the viability and clonogenicity of PDAC cells in a dose-dependent manner. Furthermore, NPS-1034 inhibits the migration of PDAC cells by suppressing MET/PI3K/AKT axis-induced epithelial-to-mesenchymal transition (EMT). The combination of NPS-1034 with fluorouracil or oxaliplatin demonstrated a synergistic effect, significantly reducing cell viability and inducing tumor cell apoptosis compared to monotherapies. Mechanistic insights provided by next-generation sequencing indicated that NPS-1034 modulates immune responses by inducing type I interferon and tumor necrosis factor production in PDAC cells. This suggests a broader role for NPS-1034 beyond MET and AXL inhibition, positioning it as a potential immunity modulator. Overall, these findings highlight the anticancer potential of NPS-1034 in PDAC treatment in vitro, both as a monotherapy and in combination with traditional chemotherapy, offering a promising avenue for further in vivo investigation before clinical exploration. Full article

Triple-negative breast cancer (TNBC) is the most aggressive subtype with high metastasis and mortality rates. Given the lack of actionable targets such as ER and HER2, TNBC still remains an unmet therapeutic challenge. Despite harboring high CDK4/6 expression levels, the efficacy of CDK4/6 inhibition in TNBC has been limited due to the emergence of resistance. The resistance to CDK4/6 inhibition is mainly mediated by RB1 inactivation. Since our aim is to overcome resistance to CDK4/6 inhibition, in this study, we primarily used the cell lines that do not express RB1. Following a screening for activated receptor tyrosine kinases (RTKs) upon CDK4/6 inhibition, we identified the TAM (Tyro3, Axl, and MerTK) RTKs as a crucial therapeutic vulnerability in TNBC. We show that targeting the TAM receptors with a novel inhibitor, sitravatinib, significantly sensitizes TNBC to CDK4/6 inhibitors. Upon prolonged HER2 inhibitor treatment, HER2+ breast cancers suppress HER2 expression, physiologically transforming into TNBC-like cells. We further show that the combined treatment is highly effective against drug-resistant HER2+ breast cancer as well. Following quantitative proteomics and RNA-seq data analysis, we extended our study into the immunophenotyping of TNBC. Given the roles of the TAM receptors in promoting the creation of an immunosuppressive tumor microenvironment (TME), we further demonstrate that the combination of CDK4/6 inhibitor abemaciclib and sitravatinib modifies the immune landscape of TNBC to favor immune checkpoint blockade. Overall, our study offers a novel and highly effective combination therapy against TNBC and potentially treatment-resistant HER2+ breast cancer that can be rapidly moved to the clinic. Full article