Search Results (154)

Neutrophils play a key role in autoimmune diseases like rheumatoid arthritis, contributing to tissue damage through rapid recruitment and activation. In this study, we investigated the regulatory properties of two receptor-like tyrosine phosphatases (RPTPs), CD45 and CD148, in inflammatory arthritis. Using an in vivo mouse model of K/BxN serum transfer-induced arthritis, we found that CD45 and CD148 feature distinct regulatory properties during inflammatory arthritis. CD45 is required for neutrophil infiltration, cytokine release, and reactive oxygen species production, whereas CD148 deficiency leads to a delayed onset of arthritis but unaltered overall neutrophil infiltration and reduced ROS production. Furthermore, we could demonstrate that activation of Src family kinases in neutrophils is differentially regulated by CD45 and CD148 in a stimulus-dependent manner. Summarizing, our results suggest that CD45 is positively involved, while CD148 is positively and negatively involved in neutrophil recruitment and function during inflammatory arthritis. Full article

Background/Objectives: CD318 (also known as CDCP1) is a transmembrane protein that is overexpressed in many cancers and contributes to tumor progression, invasion, and metastasis by activating SRC family kinases through phosphorylation. Emerging evidence also suggests that CD318 plays a role in modulating the tumor immune microenvironment, although its precise mechanism in tumor progression is still not well understood. Methods: To investigate this, we analyzed the expression and immune-related functions of CD318 using the publicly available data from The Cancer Genome Atlas (TCGA) across colorectal adenocarcinoma (COAD), cervical squamous cell carcinoma (CESC), lung adenocarcinoma (LUAD), and pancreatic adenocarcinoma (PAAD). Results: All four cancers exhibited a high level of CD318 expression. Notably, in CESC, LUAD, and PAAD, plasmin-mediated cleavage of CD318 leads to phosphorylation of SRC and protein kinase C delta (PKCδ), which activates HIF1α and/or p38 MAPK. These downstream effectors translocate to the nucleus and promote the transcriptional upregulation of TGFβ1, fostering an immunosuppressive tumor microenvironment through Treg cell recruitment. In contrast, this signaling cascade appears to be absent in COAD. Instead, our analysis indicate that intact CD318 in COAD interacts with the surface receptors CD96 and CD160, which are found on CD8⁺ T cells and NK cells. Conclusions: This interaction enhances cytotoxic immune responses in COAD by promoting CD8⁺ T cell and NK cell activity, offering a possible explanation for the favorable prognosis associated with high CD318 expression in COAD, compared to the poorer outcomes observed in CESC, LUAD, and PAAD. Full article

Hepatocellular carcinoma (HCC) remains a major clinical challenge due to its high recurrence rate and limited response to monotherapies, such as sorafenib—the standard first-line therapy for advanced HCC. This is partly attributed to its cellular heterogeneity. Increasing evidence implies SRC family kinase (SFK) activation in HCC progression, highlighting the potential of SRC-targeted therapies. In this study, we observed that SRC and YES1 were significantly upregulated in clinical HCC specimens compared to its adjacent non-tumoral tissues (p < 0.001), suggesting relevance as therapeutic targets. High SRC expression was noticed in patients with poor prognosis, as confirmed in TCGA cohort. To evaluate the efficacy of dual targeting, we assessed the combination between SRC inhibitors, saracatinib and dasatinib, with sorafenib in six hepatic cell models, representing both S1 and S2 subtypes. Cytotoxicity assays demonstrated reduced cell viability with the combination therapies compared to either monotherapy, irrespective of the HCC subtype. Wound healing and Transwell migration assays revealed inhibition of cell migration and invasion following combination treatment, underscoring its potential to suppress metastatic behavior. RT-qPCR analysis further confirmed downregulation of the expression of MMP2 and MMP9, genes associated with HCC cell invasion. Additionally, combined therapies decreased VEGFA and HIF1A expression compared to sorafenib alone, suggesting a potential to counteract the adaptive resistance mechanisms of cells to sorafenib. In summary, the combination of SFK inhibitors with sorafenib significantly enhances anti-tumor activity, offering a promising strategy to address HCC cellular heterogeneity and improve treatment efficacy. Full article

6-Aryl-7H-pyrrolo[2,3-d]pyrimidin-4-amines have promising properties as colony-stimulating factor 1 receptor (CSF1R) inhibitors. Inspired by these antagonists, two series of 1,2,3-triazole analogues (28 compounds) were synthesized and evaluated as CSF1R inhibitors. Enzymatic IC₅₀ profiling showed that 27 of the 28 derivatives had lower IC₅₀ than the reference drug PLX-3397. Three derivatives displayed CSF1R Ba/F3 cellular IC₅₀ well below 1 µM. Profiling of the most promising triazole analogue (compound 27a) toward a panel of kinases reveals a high selectivity for CSF1R with respect to its family kinases, but 27a also inhibits ABL, SRC, and YES kinases. Molecular docking of 27a toward two CSF1R X-ray structures identified two different ligand-inverted binding poses, which triggers interest for further investigations. Full article

Lyn is a multifunctional Src-family kinase (SFK) that regulates immune signaling and has been implicated in diverse types of cancer. Unlike other SFKs, its full-length structure and regulatory dynamics remain poorly characterized. In this study, we present the first long-timescale molecular dynamics analysis of full-length Lyn, including the SH3, SH2, and SH1 domains, across wildtype, ligand-bound, and cancer-associated mutant states. Using principal component analysis, dynamic cross-correlation matrices, and network-based methods, we show that ATP binding stabilizes the kinase core and promotes interdomain coordination, while the ATP-competitive inhibitor dasatinib and specific mutations (e.g., E290K, I364N) induce conformational decoupling and weaken long-range communication. We identify integration modules and develop an interface-weighted scoring scheme to rank dynamically central residues. This analysis reveals 44 allosteric hubs spanning SH3, SH2, SH1, and interdomain regions. Finally, a random forest classifier trained on 16 MD-derived features highlights key interdomain descriptors, distinguishing functional states with an AUC of 0.98. Our results offer a dynamic and network-level framework for understanding Lyn regulation and identify potential regulatory hotspots for structure-based drug design. More broadly, our approach demonstrates the value of integrating full-length MD simulations with network and machine learning techniques to probe allosteric control in multidomain kinases. Full article

Background: Three-dimensional (3D) cell models may bridge the gap between two-dimensional (2D) cell cultures and animal models. Technical advances have led to the development of 3D-bioprinted cell models, characterized by greater reproducibility and the ability to mimic in vivo conditions. Glioblastoma multiforme (GBM) is a highly aggressive brain tumor with poor clinical outcomes due to its heterogeneity, angiogenic activity, and invasiveness. Src family kinases (SFKs) play a crucial role in GBM progression, making them attractive targets for drug development. Here, we show results about the pharmacological profile of a new prodrug synthesized from a Src inhibitor, SI306. Methods: Three-dimensional-bioprinted GBM cell models were used in predicting the antitumor activity of the prodrug SI306-PD2 with respect to its precursor, SI306. Results: Since the prodrug releases the active inhibitor through the cleavage by specific enzymes, SI306-PD2 was analyzed for stability and release kinetics in various media, including fetal bovine serum (FBS), which is normally used in cell culture. In comparison to SI306, SI306-PD2 demonstrated higher solubility in water, higher permeability across gastrointestinal and blood–brain barrier membranes, and the ability to release the drug in the presence of FBS progressively. In the 2D GBM cell model, using U87 and U251 cell lines, both compounds similarly reduced tumor cell viability. In 3D-bioprinted cell models, in the presence of an FBS-free medium, SI306-PD2 exhibited a more effective antitumor activity compared to SI306, reducing the proliferation and diameter of U251 spheroids grown within the bioprinted scaffold in a statistically significant manner. The analysis of proteins extracted from 3D scaffolds confirmed that SI306-PD2 inhibited Src activation more efficiently than SI306. Conclusions: Our study suggests that, when tissue permeability represents a discriminating characteristic, bioprinted cell models can provide a valid alternative for studying the cytotoxicity of new antitumor compounds. This approach has permitted us to ascertain the potential of the prodrug SI306-PD2 as a therapeutic agent for GBM, demonstrating better tissue penetration and antiproliferative efficacy compared to the precursor compound SI306. Full article

Background/Objectives: In recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC), the overall prognosis is poor, and systemic treatment options remain limited. While precision therapy approaches have revolutionized treatment strategies in several tumor types, molecularly informed therapies in R/M HNSCC are rare, primarily due to the low number of actionable genetic alterations identified through next-generation sequencing (NGS) panels. There is an urgent need to establish precision therapy approaches in R/M HNSCC using innovative predictive testing. Methods: We report the case of a 43-year-old patient with recurrent oral cancer who was extensively pretreated and comprehensively characterized using both descriptive and functional testing. Results: NGS revealed no targetable alterations. A tumor tissue slice radiosensitivity assay suggested radioresistance, arguing against re-irradiation. Kinome profiling identified upregulated Src-family kinases (SFK), and SFK inhibition reduced kinase activity in vitro. Most notably, mRNA analysis demonstrated high Trop-2 overexpression, confirmed by immunohistochemistry (3+ in 100% of tumor cells). Following six cycles of the Trop-2-directed antibody–drug conjugate Sacituzumab govitecan (SG), the patient had an impressive clinical response. Conclusions: Tumor characterization beyond genetic profiling can identify novel treatment options in therapy-refractory HNSCC. This is the first report of “real-world” data on promising antitumor efficacy of SG in a heavily pretreated oral cancer patient with Trop-2 overexpression. Consistent with the findings of the Basket TROPiCS-03 study, SG appears to be a promising novel therapy option for R/M HNSCC after failure of immunotherapy and chemotherapy, particularly in patients with Trop-2 overexpression. Full article

Previous studies have demonstrated neuronal and microglial Fyn, a Src family kinase (SFK), and how its interactions with tau contribute to epileptogenesis. Saracatinib, a Fyn/SFK inhibitor, modifies disease progression in rat kainate (KA) epilepsy models. In this study, we investigated neuronal-specific fyn knockdown effects on Fyn–tau signaling, neurodegeneration, and gliosis using a calcium/calmodulin-dependent protein kinase II (CaMKII)-promoter-driven adeno-associated viral vector (AAV9)-mediated fyn-shRNA injection in the rat hippocampus. Eight days following AAV administration, rats received repeated low-dose KA injections intraperitoneally to induce status epilepticus (SE). Both fyn-shRNA and control groups showed comparable SE severity, indicating inadequate neuronal fyn knockdown at this timepoint. Two weeks post fyn-shRNA injection, hippocampal Fyn significantly decreased, alongside reductions in NR2B, pNR2B^Y1472, PSD95, and total tau. There was also a compensatory activation of SFK (pSFK^Y416:Fyn) and tau hyperphosphorylation (AT8:total tau), negatively correlating with NeuN expression. Proximity ligation assay indicated unchanged Fyn–tau interactions, suggesting tau interactions with alternative SH3 domain proteins. Persistent neuronal loss, astrogliosis, and microgliosis suggested limited effectiveness of neuronal-specific fyn knockdown at this timepoint. An extended-duration fyn knockdown study, or using broad SFK inhibitors such as saracatinib or tau-SH3 blocking peptides, may effectively prevent SE-induced epileptogenesis. Full article

It is well-established that mitochondrial dysfunction plays a critical role in the development of pulmonary hypertension (PH). However, the molecular mechanisms and how the individual electron transport complexes (ETC) may be affected are poorly understood. In this study, we identified decreased ETC Complex I activity and assembly and linked these changes to disrupted mitochondrial bioenergetics in pulmonary arterial endothelial cells (PAECs) isolated from a lamb model of PH with increased pulmonary blood flow (Shunt). These derangements were associated with decreased mitochondrial activity of the protein tyrosine kinase, pp60^Src. Treating Control PAECs with either the Src family kinase inhibitor, PP2, or the siRNA-mediated knockdown of pp60^Src was able to recapitulate the adverse effects on ETC Complex I activity and assembly and mitochondrial bioenergetics. Conversely, restoring pp60^Src activity in lamb PH PAECs re-established ETC Complex I activity, improved ETC Complex I assembly and enhanced mitochondrial bioenergetics. Phosphoprotein enrichment followed by two-dimensional gel electrophoresis and tandem mass spectrometry was used to identify three ETC Complex I subunits (NDUFS1, NDUFAF5, and NDUFV2) as pp60^Src substrates. Finally, we demonstrated that the pY levels of NDUFS1, NDUFAF5, and NDUFV2 are decreased in lamb PH PAECs. Enhancing mitochondrial pp60^Src activity could be a therapeutic strategy to reverse PH-related mitochondrial dysfunction. Full article

Colorectal cancer (CRC) is the third most common cancer globally, with limited effective biomarkers and sensitive therapeutic targets. An increasing number of studies have highlighted the critical role of tumor microenvironment (TME) imbalances, particularly immune escape due to impaired chemokine-mediated trafficking, in tumorigenesis and progression. Notably, CC chemokines (CCLs) have been shown to either promote or inhibit angiogenesis, metastasis, and immune responses in tumors, thereby influencing cancer development and patient outcomes. However, the diagnostic and prognostic significance of CCLs in CRC remains unclear. In this study, multiple online tools for bioinformatics analyses were utilized. The findings revealed that the mRNA expression levels of CCL3, CCL4, and CCL26 were significantly elevated in CRC tissues compared to normal tissues, whereas CCL2, CCL5, CCL11, CCL21, and CCL28 mRNA levels were markedly downregulated. Additionally, dysregulation of CCL4, CCL5, and CCL21 was strongly associated with clinical staging, and elevated levels of CCL4, CCL11, and CCL28 were linked to significantly prolonged survival in CRC patients. Functional enrichment analysis indicated that the cellular roles of CCLs were predominantly associated with the chemokine, Wnt, and Toll-like receptor signaling pathways, as well as protein kinase activity. Furthermore, transcriptional regulation of most CCLs involved RELA and NFKB1. Key downstream targets included members of the SRC family of tyrosine kinases (HCK, LYN, and LCK), serine/threonine kinases (ATR and ATM), and others such as CSNK1G2, NEK2, and CDK2. Moreover, CCLs (CCL2, CCL3, CCL4, CCL5, CCL11, CCL21, and CCL28) exhibited strong correlations with major infiltration-related immune cells, including B cells, CD8⁺ T cells, CD4⁺ T cells, macrophages, neutrophils, and dendritic cells. In conclusion, our study provides novel insights into the potential utility of CCLs as biomarkers and therapeutic targets for CRC prevention and immunotherapy. Full article

(i) Background: The increasing prevalence of allergic diseases highlights the need for effective treatments. Lonicera caerulea fruit has been recognized for its anti-inflammatory, anti-cancer, and neuroprotective effects, but the mechanisms underlying its anti-allergic properties remain unclear. (ii) Objective: This study aims to evaluate the total phenolic, total flavonoid, and cyanidin-3-glucoside (C3G) contents of Lonicera caerulea extract (HR2302-30E) and to investigate its antioxidant and anti-allergic activities. (iii) Methods: Using an IgE-stimulated RBL-2H3 cell model, we assessed the effects of HR2302-30E and C3G on mast cell degranulation, β-hexosaminidase and histamine release. Western blot analysis was performed to evaluate the expression of high-affinity IgE receptor (FcεRI)β/γ and the phosphorylation of Src family kinases (Syk, Fyn). We also examined the phosphorylation of downstream factors phospholipase Cγ, protein kinase Cδ, and mitogen-activated protein kinase. (iv) Results: Total phenolic, flavonoid, and C3G contents of HR2302-30E were 18.73 mg GAE/g, 11.83 mg QE/g, and 7.02 mg/g, respectively. In IgE-activated mast cells, HR2302-30E and C3G inhibited β-hexosaminidase and histamine release. Western blot analysis revealed reduced expression of FcεRIβ/γ and decreased phosphorylation of key downstream signaling molecules. Conclusions: These findings suggest that HR2302-30E and C3G modulate FcεRI signaling, indicating their potential as natural anti-allergic agents. Full article

Although antimicrobial peptides (AMPs) exhibit a range of biological functions, reports on AMPs with therapeutic effects in allergic disorders are limited. In this study, we investigated the anti-allergic effects of Pro10-1D, a 10-meric AMP derived from insect defensin protaetiamycine. Our findings demonstrate that Pro10-1D effectively inhibits antigen-induced degranulation of mast cells (MCs) with IC₅₀ values of approximately 11.6 μM for RBL-2H3 cells and 2.7 μM for bone marrow-derived MCs. Furthermore, Pro10-1D suppressed the secretion of cytokines with IC₅₀ values of approximately 2.8 μM for IL-4 and approximately 8.6 μM for TNF-α. Mechanistically, Pro10-1D inhibited the Syk-LAT-PLCγ1 signaling pathway in MCs and decreased the activation of mitogen-activated protein kinases (MAPKs). Pro10-1D demonstrated a dose-dependent reduction in IgE-mediated passive cutaneous anaphylaxis in mice with an ED₅₀ value of approximately 7.6 mg/kg. Further investigation revealed that Pro10-1D significantly reduced the activity of key kinases Fyn and Lyn, which are critical in the initial phase of the FcεRI-mediated signaling pathway, with IC₅₀ values of approximately 22.6 μM for Fyn and approximately 1.5 μM for Lyn. Collectively, these findings suggest that Pro10-1D represents a novel therapeutic candidate for the treatment of IgE-mediated allergic disorders by targeting the Lyn/Fyn Src family kinases in MCs. Full article

As a founding member of the Src family of kinases, Src has been confirmed to participate in the regulation of immune responses, integrin signaling, and motility. Ducks are usually asymptomatic carriers of RNA viruses such as Newcastle disease virus and avian influenza virus, which can be deadly to chickens. The beneficial role of Src in modulating the immune response remains largely unknown in ducks. Here, we characterized the duck Src and found that it contains a 192-base-pair 5′ untranslated region, a 1602-base-pair coding region, and a 2541-base-pair 3′ untranslated region, encoding 533 amino acid residues. Additionally, duSrc transcripts were significantly activated in duck tissues infected by Newcastle disease virus compared to controls. The duSrc transcripts were notably widespread in all tissues examined, and the expression level was higher in liver, blood, lung, pancreas, and thymus. Moreover, we found the expression levels of IFN-β, NF-κB, IRF3, and Src were significantly increased in DEFs after infection with 5′ppp dsRNA, but there was no significant difference before and after treatment in DF1 cells. Furthermore, overexpression of duSrc followed by stimulation with 5′ppp dsRNA led to an elevation of IFN-β levels. The SH3 and PTKc domains of duSrc contributed to promoting the activity of IFN-β and NF-κB in DEFs stimulated by 5′ppp dsRNA. Full article

Lck, a member of the Src kinase family, is a non-receptor tyrosine kinase involved in immune cell activation, antigen recognition, tumor growth, and cytotoxic response. The enzyme has usually been linked to T lymphocyte activation upon antigen recognition. Lck activation is central to CD4, CD8, and NK activation. However, recently, it has become clearer that activating the enzyme in CD8 cells can be independent of antigen presentation and enhance the cytotoxic response. The role of Lck in NK cytotoxic function has been controversial in a similar fashion as the role of the enzyme in CAR T cells. Inhibiting tyrosine kinases has been a highly successful approach to treating hematologic malignancies. The inhibitors may be useful in treating other tumor types, and they may be useful to prevent cell exhaustion. New, more selective inhibitors have been documented, and they have shown interesting activities not only in tumor growth but in the treatment of autoimmune diseases, asthma, and graft vs. host disease. Drug repurposing and bioinformatics can aid in solving several unsolved issues about the role of Lck in cancer. In summary, the role of Lck in immune response and tumor growth is not a simple event and requires more research. Full article

Background: Remarkable differences exist in the outcome of systemic cancer therapies. Lymphomas and leukemias generally respond well to systemic chemotherapies, while solid cancers often fail. We engineered different human cancer cells lines to uniformly express a modified herpes simplex virus thymidine kinase TK.007 as a suicide gene when ganciclovir (GCV) is applied, thus in theory achieving a similar response in all cell lines. Methods: Fifteen different cell lines were engineered to express the TK.007 gene. XTT-cell proliferation assays were performed and the IC₅₀-values were calculated. Functional kinome profiling, mRNA sequencing, and bottom-up proteomics analysis with Ingenuity pathway analysis were performed. Results: GCV potency varied among cell lines, with lymphoma and leukemia cells showing higher susceptibility than solid cancer cells. Functional kinome profiling implies a contribution of the SRC family kinases and decreased overall kinase activity. mRNA sequencing highlighted alterations in the MAPK pathways and bottom-up proteomics showed differences in apoptotic and epithelial junction signaling proteins. Conclusions: The histogenetic origin of cells influenced the susceptibility of human malignant cells towards cytotoxic agents with leukemias and lymphomas being more sensitive than solid cancer cells. Full article