Fibroblast Growth Factor Receptor Research Articles

Real-world performance of Uromonitor® in urothelial bladder cancer detection: a multicentric trial.

To compare Uromonitor® (U-Monitor Lda, Porto, Portugal), a multitarget DNA assay that detects mutated proto-oncogenes (telomerase reverse transcriptase [TERT], fibroblast growth factor receptor 3 [FGFR-3], Kirsten rat sarcoma viral oncogene homologue [KRAS]), with urine cytology in the urine-based diagnosis of urothelial carcinoma of the bladder (UCB) within a multicentre real-world setting. This multicentre, prospective, double-blind study was conducted across four German urological centres from 2019 to 2024. We evaluated the diagnostic performance of Uromonitor compared to urine cytology in a cohort of patients with UCB and in healthy controls within a real-world setting. Sensitivity, specificity, positive-predictive value (PPV), negative-predictive value (NPV), and accuracy of the tests were measured, in addition to multivariate analyses to assess the ability of individual proto-oncogene mutations in detecting UCB. The biometric sample size was designed to achieve a 10% difference in sensitivity. Patients with UCB comprised 63.7% (339/532) of the study group. Uromonitor showed a sensitivity, specificity, PPV, NPV, accuracy, and an area-under-the-curve of 49.3%, 93.3%, 92.8%, 51.1%, 65.2%, and 0.713%, respectively. These metrics did not demonstrate statistical superiority over urine cytology in terms of sensitivity (44.6%; P = 0.316). Moreover, the comparison of additional test parameters, as well as the comparison within various sensitivity analyses, yielded no significant disparity between the two urinary tests. Multivariate logistic regression underscored the significant predictive value of a positive Uromonitor for detecting UCB (odds ratio [OR] 9.03; P < 0.001). Furthermore, mutations in TERT and FGFR-3 were independently associated with high odds of UCB detection (OR 13.30 and 7.04, respectively), while KRAS mutations did not exhibit predictive capability. Despite its innovative approach, Uromonitor fell short of confirming the superior results anticipated from previous studies in this real-world setting. The search for an optimal urine-based biomarker for detecting and monitoring UCB remains ongoing. Results from this study highlight the complexity of developing non-invasive diagnostic tools and emphasise the importance of continued research efforts to refine these technologies.

Computational biophysical characterization of the effect of gatekeeper mutations on the binding of ponatinib to the FGFR kinase

Fibroblast Growth Factor Receptor (FGFR) is connected to numerous downstream signalling cascades regulating cellular behavior. Any dysregulation leads to a plethora of illnesses, including cancer. Therapeutics are available, but drug resistance driven by gatekeeper mutation impedes the treatment. Ponatinib is an FDA-approved drug against BCR-ABL kinase and has shown effective results against FGFR-mediated carcinogenesis. Herein, we undertake molecular dynamics simulation-based analysis on ponatinib against all the FGFR isoforms having Val to Met gatekeeper mutations. The results suggest that ponatinib is a potent and selective inhibitor for FGFR1, FGFR2, and FGFR4 gatekeeper mutations. The extensive electrostatic and van der Waals interaction network accounts for its high potency. The FGFR3_VM mutation has shown resistance towards ponatinib, which is supported by their lesser binding affinity than wild-type complexes. The disengaged molecular brake and engaged hydrophobic spine were believed to be the driving factors for weak protein-ligand interaction. Taken together, the inhibitory and structural characteristics exhibited by ponatinib may aid in thwarting resistance based on Val-to-Met gatekeeper mutations at an earlier stage of treatment and advance the design and development of other inhibitors targeted at FGFRs harboring gatekeeper mutations.

Genome-wide identification of Fgfr genes and function analysis of Fgfr4 in myoblasts differentiation of Lateolabrax maculatus

Fibroblast growth factor receptors (Fgfrs) are involved in cell proliferation, differentiation, and migration via complex signaling pathways in different tissues. Our previous studies showed that fibroblast growth factor receptor 4 (fgfr4) was detected in the most significant quantitative trait loci (QTL) for growth traits. However, studies focusing on the function of fgfr4 on the growth of bony fish are still limited. In this study, we identified seven fgfr genes in spotted sea bass (Lateolabrax maculatus) genome, namely fgfr1a, fgfr1b, fgfr2, fgfr3, fgfr4, fgfr5a, and fgfr5b. Phylogenetic analysis, syntenic analysis and gene structure analysis were conducted to further support the accuracy of our annotation and classification results. Additionally, fgfr4 showed the highest expression levels among fgfrs during the proliferation and differentiation stages of spotted sea bass myoblasts. To further study the function of fgfr4 in myogenesis, dual-fluorescence in situ hybridization (ISH) assay was conducted, and the results showed co-localization of fgfr4 with marker gene of skeletal muscle satellite cells. By treating differentiating myoblasts cultured in vitro with BLU-554, the mRNA expressions of myogenin (myog) and the numbers of myotubes formed by myoblasts increased significantly compared to negative control group. These results indicated that Fgfr4 inhibits the differentiation of myoblasts in spotted sea bass. Our findings contributed to filling a research gap on fgfr4 in bony fish myogenesis and the theoretical understanding of growth trait regulation of spotted sea bass.

LGG-60. DISTRIBUTION AND CLINICAL SIGNIFICANCE OF FGFR ALTERATIONS IN PEDIATRIC AND AYA GLIOMAS

Abstract Fibroblast growth factor receptor (FGFR) alterations are prevalent in human cancers. In a large Canadian population-based cohort, encompassing over 1,300 pediatric and Adolescent and young adult (AYA) gliomas, FGFR mutations occurred in 10% of pediatric low-grade gliomas (LGG) and 20% of IDH-WT AYA LGGs. Here we assembled a large multi-institutional cohort including more than 300 mutated gliomas, aged 6 months to 87 years, 53% of which were LGG. High-grade gliomas were more common with increasing age; over 90% of pediatric cases were LGGs, compared to 30% in the AYA group. Fusions, predominantly seen in the pediatric group (70% of LGGs), contrast with FGFR3-TACC3 fusions frequent found in adult high-grade gliomas. Interestingly, FGFR mutations sometimes existed as sole drivers or co-occurred with other alterations (~30%), it is unclear how this alters tumor behavior, although gain of additional alterations could be implied in malignant transformation and poor prognosis. Despite higher incidence of high-grade gliomas in AYAs, their progression-free survival was significantly better than that of pediatric LGGs (p=0.007), largely due to the prevalence of hemispheric tumors amenable to gross total resection. Approximately 30% of our LGG cohort underwent adjuvant therapy; with available data for 28 patients, objective responses were noted in 2/12 to chemotherapy, 2/9 to MEK inhibitors, and 3/7 to FGFR inhibitors, respectively. With the increasing promise of precision targeted therapy, molecular profiling and assessment for FGFR alterations is essential. Although encouraging, further studies are needed to assess the benefit of FGFR inhibition in these patients.

Design, synthesis and antitumor activity of a novel FGFR2-selective degrader to overcome resistance of the FGFR2V564F gatekeeper mutation based on a pan-FGFR inhibitor

Aberrant activation of fibroblast growth factor receptors (FGFRs) contributes to the development and progression of multiple types of cancer. Although many FGFR inhibitors have been approved by the FDA, their long-term therapeutic efficacy is hampered by acquired resistance to gatekeeper mutations and low subtype selectivity. FGFR2 has been found to be frequently amplified or mutated in many tumors. In this study, we designed several PROTACs with different E3 ligands based on LY2874455. By screening the length of the linker and the binding site in various degraders, we obtained a novel and highly efficient FGFR2-selective degrader 28e (DC50 = 0.645 nM, DCmax = 86 %). Compound 28e selectively degraded FGFR2 and essentially avoided degradation of FGFR1,3,4 isoforms (DC50 > 300 nM). Compound 28e significantly inhibited the proliferation of FGFR2-overexpressing cell lines, including KATOIII, SNU16, and AN3CA (IC50 = 0.794 nM/0.207 nM/4.626 nM), comparable to parental inhibitors. At the same time, the preferred compound showed superiority over the parental inhibitor in kinase inhibitory activity against the gatekeeper mutant isoform FGFR2V564F (IC50 = 0.121 nM). In summary, we identified 28e as a novel selective degrader of FGFR2 with high potency and high potential to overcome resistance to gatekeeper mutation. The discovery of 28e provides new evidence for the strategy of pan-inhibitor-based development of selective degrading agents.

LGG-02. ELUCIDATING THE ROLE OF FGFR1 ALTERATIONS IN PEDIATRIC GLIOMAS

Abstract BACKGROUND Pediatric brain cancers are the leading cause of cancer-related deaths in children. We (and others) have recently found that close to 10% of all pediatric gliomas, encompassing low-grade gliomas (LGGs) and high-grade gliomas (HGGs), harbor recurrent driver alterations in FGFR proteins, most frequently FGFR1, the gene encoding Fibroblast Growth Factor Receptor 1. In pediatric gliomas, FGFR1 alterations present as either structural variants (SVs), including kinase duplications and fusion proteins, or kinase-activating single nucleotide variants (SNVs). Recurrent FGFR1 alterations represent a promising therapeutic target for precision medicine approaches, however a challenge has been the lack of clinical trials for FGFR inhibitors. A major goal of this project is to identify preclinical FGFR inhibitor candidates for FGFR1-altered pediatric gliomas. METHODS We have generated isogenic mouse and human neural stem cell (NSC) models driven by FGFR1 and BRAF alterations commonly seen in pediatric gliomas to test the oncogenic properties and therapeutic capacities of these alterations. RESULTS We found that NSC lines grow independent of growth factors and form tumors in mice. RNA-sequencing of these lines revealed the FGFR1-altered lines are enriched in neuronal gene programs. The FGFR1-altered models are exquisitely sensitive to the four FDA-approved panFGFR inhibitors Infigratinib, Erdafitinib, Pemigatinib, and Futibatinib. However, the FGFR1 SNV + PTPN11 co-occurring SNV line is the least sensitive to FGFR inhibition, which suggests combination therapies may be needed. Combination drug studies with FGFR inhibition in our FGFR1-altered lines reveal the best synergy with mTOR inhibition. Finally, we present examples of case studies of patients with FGFR1-altered tumors treated with targeted inhibitors. CONCLUSIONS Taken together, our studies have established models that have generated key insights into the biology of FGFR1-altered gliomas and how to best target them therapeutically.

Evaluation of antitumor potential of an anti-glypican-1 monoclonal antibody in preclinical lung cancer models reveals a distinct mechanism of action.

The main objective of this study was to investigate the antitumor effect of a mouse anti-human glypican-1 (GPC1) monoclonal antibody (mAb) on non-small cell lung carcinoma (NSCLC) and associated molecular mechanisms. The anti-proliferative and anti-migratory activities of anti-GPC1 mAb were examined in A549 and H460 NSCLC cells and LL97A lung fibroblasts. The inhibitory effect of anti-GPC1 mAb on tumor growth was evaluated in an orthotopic lung tumor model. The in vitro study showed that anti-GPC1 mAb profoundly inhibited the anchorage-independent growth of A549 and H460 NSCLC cells and exhibited relatively high cytotoxic activities towards LL97A lung fibroblasts, A549/LL97A and H460/LL97A coculture spheroids. Moreover, anti-GPC1 mAb significantly decreased the expression of phospho-Src (p-Src; Tyr416), p-Akt (Ser473) and β-catenin in the co-cultured LL97A lung fibroblasts, and the expression of phospho-mitogen-activated protein kinase kinase (p-MEK; Ser217/221) and phospho-90 kDa ribosomal s6 kinase (p-p90RSK; Ser380) in co-cultured A549 cells. When anti-GPC1 mAb was administered to tumor-bearing mice, the inhibitory effect of anti-GPC1 mAb on the orthotopic lung tumor growth was not statistically significant. Nonetheless, results of Western blot analysis showed significant decrease in the phosphorylation of fibroblast growth factor receptor 1 (FGFR1) at Tyr766, Src at Tyr416, extracellular signal-regulated kinase (ERK) at Thr202/Tyr204, 90 kDa ribosomal S6 kinase (RSK) at Ser380, glycogen synthase kinases 3α (GSK3α) at Ser21 and GSK3β at Ser9 in tumor tissues. These data implicate that anti-GPC1 mAb treatment impairs the interaction between tumor cells and tumor associated fibroblasts by attenuating the paracrine FGFR signal transduction. The relatively potent cytotoxicity of anti-GPC1 mAb in lung fibroblasts and its potential inhibitory effect on the paracrine FGFR signal transduction warrant further studies on the combined use of this mAb with targeted therapeutics to improve therapeutic outcomes in lung cancer.

Review of patients with achondroplasia: a single-center's experience with follow-up and associated morbidities

Achondroplasia (ACH; MIM #100,800), caused by a heterozygous gain of function pathogenic variant in the fibroblast growth factor receptor 3 gene (FGFR3; MIM*134,934), is the most prevalent and most readily identifiable cause of disproportionate short stature that is compatible with life. In addition, individuals with achondroplasia face significant medical, functional, and psychosocial challenges throughout their lives. This study assessed associated morbidities in patients with achondroplasia at a single center in Turkey. In this study, the clinical findings and associated morbidities of a group of patients with achondroplasia (n = 68) with clinical multidisciplinary follow-up at a single center between the years 2005–2023 are evaluated retrospectively. A total of 68 patients, 30 male (44.1%) and 38 female (55.9%), were evaluated. In the majority (84.2%) of patients, shortness of extremities was detected in the prenatal period at an average of 28.7 gestational weeks (± 3.6 SDS) with the aid of ultrasonography. More than half (n = 34/63, 54%) of the patients had a father of advanced paternal age (≥ 35 years). Among the complications, respiratory system manifestations, including obstructive sleep apnea (70%), ear-nose-throat manifestations including adenoid hypertrophy (56.6%) and otitis media (54.7%), neurological manifestations due to foramen magnum stenosis (53.2%), and skeletal manifestations including scoliosis (28.8%), are represented among the most common. The mortality rate was 7.3% (n = 5/68).Conclusion: This study not only represents the first retrospective analysis of the associated morbidities of patients with achondroplasia from a single center in Turkey but also will provide a reference point for future studies.

Targeting metabolic reprogramming to overcome drug resistance in advanced bladder cancer: insights from gemcitabine- and cisplatin-resistant models.

Gemcitabine plus cisplatin (GC) combination chemotherapy is the primary treatment for advanced bladder cancer (BC) with unresectable or metastatic disease. However, most cases develop resistance to this therapy. We investigated whether drug resistance could be targeted through metabolic reprogramming therapies. Metabolomics analyses in our lab's gemcitabine- and cisplatin-resistant cell lines revealed increased phosphoglycerate dehydrogenase (PHGDH) expression in gemcitabine-resistant cells compared with parental cells. Isocitrate dehydrogenase 2 (IDH2) gain of function stabilized hypoxia-inducible factor1α (HIF1α) expression, stimulating aerobic glycolysis. In gemcitabine-resistant cells, elevated fumaric acid suppressed prolyl hydroxylase domain-containing protein 2/Egl nine homolog 1 (PHD2) and stabilized HIF1α expression. PHGDH downregulation or inhibition in gemcitabine-resistant BC cells inhibited their proliferation, migration, and invasion. Cisplatin-resistant cells showed elevated fatty acid metabolism, upregulating fatty acid synthase (FASN) downstream of tyrosine kinase. Using the fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitor erdafitinib, we inhibited malonyl-CoA production, which is crucial for fatty acid synthesis, and thereby suppressed upregulated HIF1α expression. Combination treatment with NCT503 and erdafitinib synergistically suppressed tumor cell proliferation and induced apoptosis in vitro and in vivo. Understanding these mechanisms could enable innovative BC therapeutic strategies to be developed.

Defective FGFR1 Signaling Disrupts Glucose Regulation: Evidence From Humans With FGFR1 Mutations.

Activation of fibroblast growth factor receptor 1 (FGFR1) signaling improves the metabolic health of animals and humans, while inactivation leads to diabetes in mice. Direct human genetic evidence for the role of FGFR1 signaling in human metabolic health has not been fully established. We hypothesized that individuals with naturally occurring FGFR1 variants ("experiments of nature") will display glucose dysregulation. Participants with rare FGFR1 variants and noncarrier controls. Using a recall-by-genotype approach, we examined the β-cell function and insulin sensitivity of 9 individuals with rare FGFR1 deleterious variants compared to 27 noncarrier controls, during a frequently sampled intravenous glucose tolerance test at the Reproductive Endocrine Unit and the Harvard Center for Reproductive Medicine, Massachusetts General Hospital. FGFR1-mutation carriers displayed higher β-cell function in the face of lower insulin sensitivity compared to controls. These findings suggest that impaired FGFR1 signaling may contribute to an early insulin resistance phase of diabetes pathogenesis and support the candidacy of the FGFR1 signaling pathway as a therapeutic target for improving the human metabolic health.

Disease-Modifying Effects of Lenvatinib, a Multiple Receptor Tyrosine Kinase Inhibitor, on Posttraumatic Osteoarthritis of the Knee.

Angiogenesis and vascular endothelial growth factor (VEGF) are involved in osteoarthritis (OA). We previously reported the inhibitory effect of bevacizumab in a rabbit model of OA. In the current study, we investigated the effects of lenvatinib, an angiogenesis inhibitor targeting the VEGF and fibroblast growth factor receptors, on synovitis, osteophyte formation, and cartilage degeneration in a rabbit OA model. Posttraumatic OA was induced by anterior cruciate ligament transection (ACLT) on one knee of each rabbit. Rabbits were placed into four groups according to the following lenvatinib doses: untreated control (n = 12), L0.3: 0.3 mg/kg/day (n = 15), L1.0: 1.0 mg/kg/day (n = 14), and L3.0: 3.0 mg/kg/day (n = 13) groups. We evaluated limb pain using the weight distribution ratio measured with an incapacitance tester, macroscopic osteophyte formation, and femoral condyle synovium and cartilage histology. For cartilage evaluation, the following distal sites of the femur were evaluated separately: femoral-tibial (FT), femoral-patellar (FP), and femoral corner (between FP and FT). The weight distribution ratio at 12 weeks after surgery was higher in the L0.3 and L1.0 groups than in the control group. Osteophyte formation and synovitis scores were significantly lower in the L0.3, L1.0, and L3.0 groups than in the control group. The Osteoarthritis Research Society International scores of the FT, corner, and FP sites in the L0.3 group were lower than in the control group. The cartilage thickness ratio at the FT and corner sites was significantly lower in the L0.3 group than in the control group. Krenn's grading system of cartilage synovitis showed that all lenvatinib-administered groups had significantly lower scores than the control group. MMP3 expression level in cartilage tissue was significantly lower in the L3.0 group compared with the other three groups. ADAMTS5 expression was lower in the L3.0 group compared with the control and L0.3 groups. Oral administration of lenvatinib inhibited synovitis, osteophyte formation, and cartilage degeneration and reduced pain in a rabbit ACLT model. Lenvatinib is an oral VEGF inhibitor that is easier to administer than other VEGF inhibitors and may have potential as a treatment of posttraumatic OA.

Active and machine learning-enhanced discovery of new FGFR3 inhibitor, Rhapontin, through virtual screening of receptor structures and anti-cancer activity assessment.

Introduction: This study bridges traditional remedies and modern pharmacology by exploring the synergy between natural compounds and Ceritinib in treating Non-Small Cell Lung Cancer (NSCLC), aiming to enhance efficacy and reduce toxicities. Methods: Using a combined approach of computational analysis, machine learning, and experimental procedures, we identified and analyzed PD173074, Isoquercitrin, and Rhapontin as potential inhibitors of fibroblast growth factor receptor 3 (FGFR3). Machine learning algorithms guided the initial selection, followed by Quantitative Structure-Activity Relationship (QSAR) modeling and molecular dynamics simulations to evaluate the interaction dynamics and stability of Rhapontin. Physicochemical assessments further verified its drug-like properties and specificity. Results: Our experiments demonstrate that Rhapontin, when combined with Ceritinib, significantly suppresses tumor activity in NSCLC while sparing healthy cells. The molecular simulations and physicochemical evaluations confirm Rhapontin's stability and favorable interaction with FGFR3, highlighting its potential as an effective adjunct in NSCLC therapy. Discussion: The integration of natural compounds with established cancer therapies offers a promising avenue for enhancing treatment outcomes in NSCLC. By combining the ancient wisdom of natural remedies with the precision of modern science, this study contributes to evolving cancer treatment paradigms, potentially mitigating the side effects associated with current therapies.

Bemarituzumab plus mFOLFOX6 as first-line treatment in East Asian patients with FGFR2b-overexpressing locally advanced or metastatic gastric/gastroesophageal junction cancer: subgroup of FIGHT final analysis

BackgroundIn the FIGHT study (NCT03694522) bemarituzumab, a humanized monoclonal antibody selective for fibroblast growth factor receptor 2b (FGFR2b), plus mFOLFOX6 showed clinically meaningful efficacy in patients with FGFR2b-positive (2+/3+ membranous staining by immunohistochemistry) locally advanced unresectable/metastatic gastric/gastroesophageal cancer (G/GEJC). A meaningful proportion of patients in FIGHT were enrolled in East Asia, reflecting global epidemiology of G/GEJC.MethodsThis subgroup analysis of the global, phase 2, double-blind FIGHT study included all patients enrolled in East Asian sites. Patients were randomized 1:1 to bemarituzumab-mFOLFOX6 (15 mg/kg and one 7.5 mg/kg dose on cycle 1, day 8) or matching placebo-mFOLFOX6. The primary endpoint was investigator-assessed progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate, and safety. Efficacy was evaluated after a minimum follow-up of 24 months.ResultsThe East Asian subgroup comprised 89 patients (57% of overall study population); 45 were randomized to bemarituzumab-mFOLFOX6 and 44 to placebo-mFOLFOX6. Median PFS (95% confidence interval [CI]) was 12.9 months (8.8–17.9) with bemarituzumab-mFOLFOX6 and 8.2 months (5.6–10.3) with placebo-mFOLFOX6 (HR 0.50, 95% CI 0.29–0.87); median OS (95% CI) was 24.7 months (13.8–33.1) vs 12.9 months (9.3–21.4), respectively (HR 0.56, 95% CI 0.32–0.96). Treatment benefit was more pronounced in patients with FGFR2b-positive G/GEJC in ≥ 10% of tumor cells. No new safety signals were reported.ConclusionIn East Asian patients with FGFR2b-positive advanced/metastatic G/GEJC enrolled in the global FIGHT study, bemarituzumab-mFOLFOX6 showed clinically meaningful outcomes over placebo-mFOLFOX6.

A selective Fibroblast Growth Factor Receptor 1/2 PROTAC degrader with antitumor activity.

The aberrant activation of fibroblast growth factor receptor (FGFR) acts as a potent driver of multiple types of human cancers. Despite the development of several conventional small-molecular FGFR inhibitors, their clinical efficacy is largely compromised due to low selectivity and side effects. Here, we report the selective FGFR1/2-targeting proteolysis targeting chimeric (PROTAC), BR-cpd7 that displays significant isoform specificity to FGFR1/2 with DC50 values around 10 nM, while sparing FGFR3. The following mechanistic investigation reveals the reduced FGFR signaling, through which BR-cpd7 induces cell cycle arrest and consequently blocks the proliferation of multiple FGFR1/2-dependent tumor cells. Importantly, BR-cpd7 has almost no anti-proliferative activity against cancer cells without FGFR aberrations, furtherly supporting its selectivity. In vivo, BR-cpd7 exhibits robust antitumor effects in FGFR1-dependent lung cancer at well-tolerated dose schedules, accompanied by complete FGFR1 depletion. Overall, we identify BR-cpd7 as a promising candidate for developing a selective FGFR1/2-targeted agent, thereby offering a new therapeutic strategy for human cancers in which FGFR1/2 plays a critical role.

Modulation of FGF pathway signaling and vascular differentiation using designed oligomeric assemblies

Many growth factors and cytokines signal by binding to the extracellular domains of their receptors and driving association and transphosphorylation of the receptor intracellular tyrosine kinase domains, initiating downstream signaling cascades. To enable systematic exploration of how receptor valency and geometry affect signaling outcomes, we designed cyclic homo-oligomers with up to 8 subunits using repeat protein building blocks that can be modularly extended. By incorporating a de novo-designed fibroblast growth factor receptor (FGFR)-binding module into these scaffolds, we generated a series of synthetic signaling ligands that exhibit potent valency- and geometry-dependent Ca2+ release and mitogen-activated protein kinase (MAPK) pathway activation. The high specificity of the designed agonists reveals distinct roles for two FGFR splice variants in driving arterial endothelium and perivascular cell fates during early vascular development. Our designed modular assemblies should be broadly useful for unraveling the complexities of signaling in key developmental transitions and for developing future therapeutic applications.

Macrophage-derived FGFR1 drives atherosclerosis through PLCγ-mediated activation of NF-κB inflammatory signalling pathway.

Atherosclerosis (AS) is a leading cause of cardiovascular morbidity and mortality. Atherosclerotic lesions show increased levels of proteins associated with the fibroblast growth factor receptor (FGFR) pathway. However, the functional significance and mechanisms governed by FGFR signalling in AS are not known. In the present study, we investigated fibroblast growth factor receptor 1 (FGFR1) signalling in AS development and progression. Examination of human atherosclerotic lesions and aortas of Apoe-/- mice fed a high-fat diet (HFD) showed increased levels of FGFR1 in macrophages. We deleted myeloid-expressed Fgfr1 in Apoe-/- mice and showed that Fgfr1 deficiency reduces atherosclerotic lesions and lipid accumulations in both male and female mice upon HFD feeding. These protective effects of myeloid Fgfr1 deficiency were also observed when mice with intact FGFR1 were treated with FGFR inhibitor AZD4547. To understand the mechanistic basis of this protection, we harvested macrophages from mice and show that FGFR1 is required for macrophage inflammatory responses and uptake of oxidized LDL. RNA sequencing showed that FGFR1 activity is mediated through phospholipase-C-gamma (PLCγ) and the activation of nuclear factor-κB (NF-κB) but is independent of FGFR substrate 2. Our study provides evidence of a new FGFR1-PLCγ-NF-κB axis in macrophages in inflammatory AS, supporting FGFR1 as a potentially therapeutic target for AS-related diseases.

Binding Analysis of Sf-SR-C MAM Domain and Sf-FGFR Ectodomain to Vip3Aa.

Bacillus thuringiensis Vip3Aa has been widely used in transgenic crops to resist the erosion of insects. The Scavenger Receptor-C (SR-C) and Fibroblast Growth Factor Receptor (FGFR) of Spodoptera frugiperda (Sf-SR-C and Sf-FGFR) have formerly been identified as the cell receptors of Vip3Aa. However, the interaction mechanism of Vip3Aa binding to Sf-SR-C or Sf-FGFR is still unknown. Here, we purified the MAM domain of Sf-SR-C (Sf-MAM) and the Sf-FGFR ectodomain expressed extracellularly by Sf9 cells. We then solved the crystal structure of the Sf-MAM domain. Structure docking analysis of the Sf-MAM and Vip3Aa C-terminal domain (CTD) excluded the possibility of the two proteins binding. A further surface plasmon resonance (SPR) assay also revealed that the Sf-MAM and Sf-FGFR ectodomain could not bind to the Vip3Aa protein. Our results have raised the urgency of determining the authentic cell receptor for Vip3Aa.

Fibroblast growth factor receptor 1 gene mutation as a potential risk factor for spontaneous intracranial hemorrhage in pediatric low-grade glioma patients.

Fibroblast growth factor receptor 1 (FGFR1) mutations have been associated with poorer prognoses in pediatric central nervous system tumor patients. A recent study highlighted a link between FGFR1 mutations and spontaneous intracranial hemorrhage (ICH), demonstrating that all patients with an FGFR1 alteration experienced hemorrhage at some point during their course of treatment. The current study examined 50 out of 67 pediatric patients with low-grade gliomas (LGGs) who had genomic testing between 2011 and 2022 at our institution to determine whether a correlation exists between FGFR1 mutations and spontaneous ICH. We found that of the 50 patients with genomic data, 7 (14%) experienced ICH, and an additional spontaneous hemorrhage was recorded; however, no genomic testing was performed for this case. Five of the seven patients (71.4%) had an FGFR1 modification. In our patient population, 6 expressed a detectable FGFR1 mutation (66.7% [4/6] had N546K alteration, 16.7% [1/6] FGFR1 exons duplication, and 16.7% [1/6] had a variant of unknown significance [VUS]). The patient with the FGFR1 VUS had no reported spontaneous hemorrhage. Statistical analysis found a significant association between FGFR1 and spontaneous intracranial hemorrhage (P-value = < .0001). In the patient population, all cases of PTPN11 alterations (n = 3) co-occurred with FGFR1 mutations. Our case series highlights this link between the FGFR1 mutation and spontaneous intracranial hemorrhage in pediatric LGGs.

Diverse Fgfr1 signaling pathways and endocytic trafficking regulate mesoderm development.

The fibroblast growth factor (FGF) pathway is a conserved signaling pathway required for embryonic development. Activated FGF receptor 1 (FGFR1) drives multiple intracellular signaling cascade pathways, including ERK/MAPK and PI3K/AKT, collectively termed canonical signaling. However, unlike Fgfr1-null embryos, embryos containing hypomorphic mutations in Fgfr1 lacking the ability to activate canonical downstream signals are still able to develop to birth but exhibit severe defects in all mesodermal-derived tissues. The introduction of an additional signaling mutation further reduces the activity of Fgfr1, leading to earlier lethality, reduced somitogenesis, and more severe changes in transcriptional outputs. Genes involved in migration, ECM interaction, and phosphoinositol signaling were significantly downregulated, proteomic analysis identified changes in interactions with endocytic pathway components, and cells expressing mutant receptors show changes in endocytic trafficking. Together, we identified processes regulating early mesoderm development by mechanisms involving both canonical and noncanonical Fgfr1 pathways, including direct interaction with cell adhesion components and endocytic regulation.

Prognostic value of FGFR2 alterations in patients with iCCA undergoing surgery or systemic treatments: A meta-analysis.

Over recent years, there has been a notable rise in the incidence of intrahepatic cholangiocarcinoma (iCCA), which presents a significant challenge in treatment due to its complex disease characteristics and prognosis. Notably, the identification of fibroblast growth factor receptor 2 (FGFR2) fusion/rearrangement, a potential oncogenic driver primarily observed in iCCA, raises questions about its impact on the prognostic outcomes of patients undergoing surgical intervention or other therapeutic approaches. A comprehensive search from inception to July 2023 was conducted across PubMed, Embase, Web of Science, and the Cochrane Library databases. The objective was to identify relevant publications comparing the prognosis of FGFR2 alterations and no FGFR2 alterations groups among patients with iCCA undergoing surgical resection or other systemic therapies. The primary outcome indicators, specifically Overall Survival (OS) and Disease-Free Survival (DFS), were estimated using Hazard Ratios (HRs) with 95% confidence intervals (CIs), and statistical significance was defined as p < .05. Study quality was assessed using the Newcastle-Ottawa Quality Assessment Scale. Statistical analyses were performed using Review Manager 5.4 software and Stata, version 12.0. Six studies, involving 1314 patients (FGFR2 alterations group n = 173 and no FGFR2 alterations group n = 1141), were included in the meta-analysis. The analysis revealed that the FGFR2 alterations group exhibited a significantly better OS prognosis compared to the no FGFR2 alterations group, with a fixed-effects combined effect size HR = 1.31, 95%CI = 1.001-1.715, p = .049. Furthermore, meta-regression and subgroup analysis showed that the length of the follow-up period did not introduce heterogeneity into the results. This finding indicates the stability and reliability of the study outcomes. The current study provides compelling evidence that FGFR2 alterations are frequently associated with improved survival outcomes for patients with iCCA undergoing surgical resection or other systemic treatments. Additionally, the study suggests that FGFR2 holds promise as a safe and dependable therapeutic target for managing metastatic, locally advanced or unresectable iCCA. This study offers a novel perspective in the realm of targeted therapy for iCCA, presenting a new and innovative approach to its treatment.