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1.
Front Immunol ; 15: 1390453, 2024.
Article in English | MEDLINE | ID: mdl-38962005

ABSTRACT

Fibroblast growth factors (FGFs) are a versatile family of peptide growth factors that are involved in various biological functions, including cell growth and differentiation, embryonic development, angiogenesis, and metabolism. Abnormal FGF/FGF receptor (FGFR) signaling has been implicated in the pathogenesis of multiple diseases such as cancer, metabolic diseases, and inflammatory diseases. It is worth noting that macrophage polarization, which involves distinct functional phenotypes, plays a crucial role in tissue repair, homeostasis maintenance, and immune responses. Recent evidence suggests that FGF/FGFR signaling closely participates in the polarization of macrophages, indicating that they could be potential targets for therapeutic manipulation of diseases associated with dysfunctional macrophages. In this article, we provide an overview of the structure, function, and downstream regulatory pathways of FGFs, as well as crosstalk between FGF signaling and macrophage polarization. Additionally, we summarize the potential application of harnessing FGF signaling to modulate macrophage polarization.


Subject(s)
Fibroblast Growth Factors , Macrophages , Receptors, Fibroblast Growth Factor , Signal Transduction , Humans , Macrophages/immunology , Macrophages/metabolism , Fibroblast Growth Factors/metabolism , Animals , Receptors, Fibroblast Growth Factor/metabolism , Macrophage Activation/immunology , Inflammation/immunology , Inflammation/metabolism
2.
ESMO Open ; 9(7): 103625, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38986210

ABSTRACT

BACKGROUND: Pemigatinib is an oral, potent, selective fibroblast growth factor receptor (FGFR) 1-3 inhibitor. FIGHT-101, a three-part, open-label, first-in-human, phase I/II study (NCT02393248), evaluated pemigatinib in patients with advanced solid tumors. In parts 1 and 2, pemigatinib monotherapy had a manageable safety profile and antitumor activity in FGFR-altered tumors. Part 3 (pemigatinib combination therapies) results are presented here. PATIENTS AND METHODS: Patients received 9, 13.5, or 20 mg oral once-daily pemigatinib on continuous or intermittent schedules with gemcitabine and cisplatin (pemi/gem/cis), docetaxel (pemi/doc), trastuzumab (pemi/tras), pembrolizumab (pemi/pembro), or retifanlimab (pemi/reti) irrespective of whether the tumor was confirmed as FGFR altered. Primary endpoints were safety and pharmacodynamics. Secondary endpoints were investigator-assessed tumor objective response rates (ORRs) and pharmacokinetics (PK). RESULTS: Of 65 enrolled patients (pemi/gem/cis, n = 8; pemi/doc, n = 7; pemi/tras, n = 6; pemi/pembro, n = 26; pemi/reti, n = 18), all discontinued. Treatment-emergent adverse events (TEAEs) were generally consistent with individual drug AEs. Serious and grade ≥3 TEAEs occurred in 0%-85.7% and 33.3%-100.0% of patients across treatment groups, respectively. All pemigatinib combinations demonstrated steady-state PK comparable to monotherapy. Pharmacodynamic effects in all pemigatinib combinations, except pemi/gem/cis, were consistent with monotherapy. Less inhibition of FGFR2α phosphorylation was observed with this combination. ORRs (95% confidence interval) were 37.5% [8.5% to 75.5% (pemi/gem/cis)], 14.3% [0.4% to 57.9% (pemi/doc)], 0% (pemi/tras), 26.9% [11.6% to 47.8% (pemi/pembro)], and 11.1% [1.4% to 34.7% (pemi/reti)]. All groups had instances of tumor shrinkage. ORRs in assessable patients with FGFR rearrangements and mutations were 50% and 33%, respectively. CONCLUSIONS: Pemigatinib combination therapy showed no unexpected toxicities. PK and pharmacodynamics were mostly consistent with pemigatinib monotherapy. Pemi/gem/cis (37.5%) and pemi/pembro (26.9%) had the highest ORR; most responders had FGFR alterations.

3.
Liver Int ; 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38829010

ABSTRACT

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

4.
Mil Med Res ; 11(1): 40, 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38902808

ABSTRACT

Fibroblast growth factor (FGF) signaling encompasses a multitude of functions, including regulation of cell proliferation, differentiation, morphogenesis, and patterning. FGFs and their receptors (FGFR) are crucial for adult tissue repair processes. Aberrant FGF signal transduction is associated with various pathological conditions such as cartilage damage, bone loss, muscle reduction, and other core pathological changes observed in orthopedic degenerative diseases like osteoarthritis (OA), intervertebral disc degeneration (IVDD), osteoporosis (OP), and sarcopenia. In OA and IVDD pathologies specifically, FGF1, FGF2, FGF8, FGF9, FGF18, FGF21, and FGF23 regulate the synthesis, catabolism, and ossification of cartilage tissue. Additionally, the dysregulation of FGFR expression (FGFR1 and FGFR3) promotes the pathological process of cartilage degradation. In OP and sarcopenia, endocrine-derived FGFs (FGF19, FGF21, and FGF23) modulate bone mineral synthesis and decomposition as well as muscle tissues. FGF2 and other FGFs also exert regulatory roles. A growing body of research has focused on understanding the implications of FGF signaling in orthopedic degeneration. Moreover, an increasing number of potential targets within the FGF signaling have been identified, such as FGF9, FGF18, and FGF23. However, it should be noted that most of these discoveries are still in the experimental stage, and further studies are needed before clinical application can be considered. Presently, this review aims to document the association between the FGF signaling pathway and the development and progression of orthopedic diseases. Besides, current therapeutic strategies targeting the FGF signaling pathway to prevent and treat orthopedic degeneration will be evaluated.


Subject(s)
Fibroblast Growth Factors , Osteoarthritis , Signal Transduction , Humans , Fibroblast Growth Factors/physiology , Fibroblast Growth Factors/metabolism , Signal Transduction/physiology , Osteoarthritis/physiopathology , Fibroblast Growth Factor-23 , Intervertebral Disc Degeneration/physiopathology , Osteoporosis/physiopathology , Osteoporosis/etiology , Sarcopenia/physiopathology , Aging/physiology , Animals
6.
Front Oncol ; 14: 1399356, 2024.
Article in English | MEDLINE | ID: mdl-38854731

ABSTRACT

We report a case of slipped capital femoral epiphysis (SCFE), an on target skeletal toxicity of a pan-FGFR TKI inhibitor, erdafitinib. A 13-year-old boy was diagnosed to have an optic pathway/hypothalamic glioma with signs of increased intracranial pressure and obstructive hydrocephalus requiring placement of ventriculo-peritoneal (VP) shunt. Sequencing of the tumor showed FGFR1-tyrosine kinase domain internal tandem duplication (FGFR1-KD-ITD). He developed hypothalamic obesity with rapid weight gain and BMI >30. At 12 weeks of treatment with erdafitinib, he developed persistent knee pain. X-ray of the right hip showed SCFE. Erdafitinib was discontinued, and he underwent surgical pinning of the right hip. MRI at discontinuation of erdafitinib showed a 30% decrease in the size of the tumor, which has remained stable at 6 months follow-up. Our experience and literature review suggest that pediatric patients who are treated with pan-FGFR TKIs should be regularly monitored for skeletal side effects.

7.
Heliyon ; 10(11): e30887, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38841436

ABSTRACT

Fibroblast growth factors and their receptors (FGFR) have major roles in both human growth and oncogenesis. In adults, therapeutic FGFR inhibitors have been successful against tumors that carry somatic FGFR mutations. In pediatric patients, trials testing these anti-tumor FGFR inhibitor therapeutics are underway, with several recent reports suggesting modest positive responses. Herein, we report an unforeseen outcome in a pre-pubescent child with an FGFR1-mutated glioma who was successfully treated with FDA-approved erdafitinib, a pan-FGFR inhibitor approved for treatment of Bladder tumors. While on treatment with erdafitinib, the patient experienced rapid skeletal and long bone overgrowth resulting in kyphoscoliosis, reminiscent of patients with congenital loss-of-function FGFR3 mutations. We utilized normal dermal fibroblast cells established from the patient as a surrogate model to demonstrate that insulin-like growth factor 1 (IGF-1), a factor important for developmental growth of bones and tissues, can activate the PI3K/AKT pathway in erdafitinib-treated cells but not the MAPK/ERK pathway. The IGF-I-activated PI3K/AKT signaling rescued normal fibroblasts from the cytotoxic effects of erdafitinib by promoting cell survival. We, therefore, postulate that IGF-I-activated P13K/AKT signaling likely continues to promote bone elongation in the growing child, but not in adults, treated with therapeutic pan-FGFR inhibitors. Importantly, since activated MAPK signaling counters bone elongation, we further postulate that prolonged blockage of the MAPK pathway with pan-FGFR inhibitors, together with actions of growth-promoting factors including IGF-1, could explain the abnormal skeletal and axial growth suffered by our pre-pubertal patient during systemic therapeutic use of pan-FGFR inhibitors. Further studies to find more targeted, and/or appropriate dosing, of pan-FGFR inhibitor therapeutics for children are essential to avoid unexpected off-target effects as was observed in our young patient.

8.
ESMO Open ; 9(6): 103488, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38838500

ABSTRACT

BACKGROUND: Fibroblast growth factor receptor 2 (FGFR2) fusions and rearrangements are clinically actionable genomic alterations in cholangiocarcinoma (CCA). Pemigatinib is a selective, potent, oral inhibitor of FGFR1-3 and demonstrated efficacy in patients with previously treated, advanced/metastatic CCA with FGFR2 alterations in FIGHT-202 (NCT02924376). We report final outcomes from the extended follow-up period. PATIENTS AND METHODS: The multicenter, open-label, single-arm, phase II FIGHT-202 study enrolled patients ≥18 years old with previously treated advanced/metastatic CCA with FGFR2 fusions or rearrangements (cohort A), other FGF/FGFR alterations (cohort B), or no FGF/FGFR alterations (cohort C). Patients received once-daily oral pemigatinib 13.5 mg in 21-day cycles (2 weeks on, 1 week off) until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) in cohort A assessed as per RECIST v1.1 by an independent review committee; secondary endpoints included duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety. RESULTS: FIGHT-202 enrolled 147 patients (cohort A, 108; cohort B, 20; cohort C, 17; unconfirmed FGF/FGFR alterations, 2). By final analysis, 145 (98.6%) had discontinued treatment due to progressive disease (71.4%), withdrawal by patient (8.2%), or adverse events (AEs; 6.8%). Median follow-up was 45.4 months. The ORR in cohort A was 37.0% (95% confidence interval 27.9% to 46.9%); complete and partial responses were observed in 3 and 37 patients, respectively. Median DOR was 9.1 (6.0-14.5) months; median PFS and OS were 7.0 (6.1-10.5) months and 17.5 (14.4-22.9) months, respectively. The most common treatment-emergent AEs (TEAEs) were hyperphosphatemia (58.5%), alopecia (49.7%), and diarrhea (47.6%). Overall, 15 (10.2%) patients experienced TEAEs leading to pemigatinib discontinuation; intestinal obstruction and acute kidney injury (n = 2 each) occurred most frequently. CONCLUSIONS: Pemigatinib demonstrated durable response and prolonged OS with manageable AEs in patients with previously treated, advanced/metastatic CCA with FGFR2 alterations in the extended follow-up period of FIGHT-202.


Subject(s)
Bile Duct Neoplasms , Cholangiocarcinoma , Pyrimidines , Humans , Cholangiocarcinoma/drug therapy , Male , Female , Middle Aged , Aged , Adult , Bile Duct Neoplasms/drug therapy , Pyrimidines/therapeutic use , Pyrimidines/pharmacology , Receptor, Fibroblast Growth Factor, Type 2 , Aged, 80 and over , Morpholines , Pyrroles
9.
Anticancer Res ; 44(6): 2393-2406, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38821585

ABSTRACT

BACKGROUND/AIM: Cholangiocarcinoma (CCA) is an aggressive tumor with limited treatment options especially in 2nd line or later treatments. Targeting fibroblast growth factor receptor (FGFR) 2 has recently emerged as a promising treatment option for patients with CCA harboring FGFR2-fusion. This study investigated the antitumor activities of tasurgratinib as an orally available FGFR1-3 inhibitor, in preclinical FGFR2-driven CCA models. MATERIALS AND METHODS: Antitumor activities of tasurgratinib were examined in vitro and in vivo using NIH/3T3 cells expressing FGFR2-fusion as FGFR2-driven CCA models, and in vivo using a CCA patient-derived xenograft model. The molecular mechanism of action of tasurgratinib was elucidated through co-crystal structure analysis with FGFR1, manual complex model analysis with FGFR2, and binding kinetics analysis with FGFR2. Furthermore, the cell-based inhibitory activities against acquired resistant FGFR2 mutations in patients with CCA treated with FGFR inhibitors were evaluated. RESULTS: Tasurgratinib showed antitumor activity in preclinical FGFR2-driven CCA models by inhibiting the FGFR signaling pathway in vitro and in vivo. Furthermore, cell-based target engagement assays indicated that tasurgratinib had potent inhibitory activities against FGFR2 mutations, such as N549H/K, which are the major acquired mutations in CCA. We also confirmed that tasurgratinib exhibited fast association and slow dissociation kinetics with FGFR2, binding to the ATP-binding site and the neighboring region, and adopting an Asp-Phe-Gly (DFG)-"in" conformation. CONCLUSION: These data demonstrate the therapeutic potential of tasurgratinib in FGFR2-driven CCA and provide molecular mechanistic insights into its unique inhibitory profile against secondary FGFR2 resistance mutations in patients with CCA treated with FGFR inhibitors.


Subject(s)
Bile Duct Neoplasms , Cholangiocarcinoma , Receptor, Fibroblast Growth Factor, Type 2 , Xenograft Model Antitumor Assays , Cholangiocarcinoma/drug therapy , Cholangiocarcinoma/genetics , Cholangiocarcinoma/pathology , Cholangiocarcinoma/metabolism , Animals , Humans , Receptor, Fibroblast Growth Factor, Type 2/antagonists & inhibitors , Receptor, Fibroblast Growth Factor, Type 2/genetics , Receptor, Fibroblast Growth Factor, Type 2/metabolism , Mice , Bile Duct Neoplasms/drug therapy , Bile Duct Neoplasms/pathology , Bile Duct Neoplasms/genetics , Bile Duct Neoplasms/metabolism , Administration, Oral , Receptor, Fibroblast Growth Factor, Type 1/antagonists & inhibitors , Receptor, Fibroblast Growth Factor, Type 1/genetics , Receptor, Fibroblast Growth Factor, Type 1/metabolism , NIH 3T3 Cells , Receptor, Fibroblast Growth Factor, Type 3/antagonists & inhibitors , Receptor, Fibroblast Growth Factor, Type 3/genetics , Receptor, Fibroblast Growth Factor, Type 3/metabolism , Cell Line, Tumor , Antineoplastic Agents/pharmacology , Antineoplastic Agents/administration & dosage , Protein Kinase Inhibitors/pharmacology , Pyrimidines/pharmacology , Pyrimidines/administration & dosage , Cell Proliferation/drug effects , Oncogene Proteins, Fusion/genetics , Oncogene Proteins, Fusion/metabolism , Oncogene Proteins, Fusion/antagonists & inhibitors
10.
J Am Heart Assoc ; 13(10): e028006, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38726894

ABSTRACT

BACKGROUND: S100a8/9 (S100 calcium binding protein a8/9) belongs to the S100 family and has gained a lot of interest as a critical regulator of inflammatory response. Our previous study found that S100a8/9 homolog promoted aortic valve sclerosis in mice with chronic kidney disease. However, the role of S100a8/9 in pressure overload-induced cardiac hypertrophy remains unclear. The present study was to explore the role of S100a8/9 in cardiac hypertrophy. METHODS AND RESULTS: Cardiomyocyte-specific S100a9 loss or gain of function was achieved using an adeno-associated virus system, and the model of cardiac hypertrophy was established by aortic banding-induced pressure overload. The results indicate that S100a8/9 expression was increased in response to pressure overload. S100a9 deficiency alleviated pressure overload-induced hypertrophic response, whereas S100a9 overexpression accelerated cardiac hypertrophy. S100a9-overexpressed mice showed increased FGF23 (fibroblast growth factor 23) expression in the hearts after exposure to pressure overload, which activated calcineurin/NFAT (nuclear factor of activated T cells) signaling in cardiac myocytes and thus promoted hypertrophic response. A specific antibody that blocks FGFR4 (FGF receptor 4) largely abolished the prohypertrophic response of S100a9 in mice. CONCLUSIONS: In conclusion, S100a8/9 promoted the development of cardiac hypertrophy in mice. Targeting S100a8/9 may be a promising therapeutic approach to treat cardiac hypertrophy.


Subject(s)
Calgranulin A , Calgranulin B , Disease Models, Animal , Fibroblast Growth Factor-23 , Fibroblast Growth Factors , Myocytes, Cardiac , NFATC Transcription Factors , Up-Regulation , Animals , Calgranulin A/metabolism , Calgranulin A/genetics , Fibroblast Growth Factors/metabolism , Fibroblast Growth Factors/genetics , Calgranulin B/metabolism , Calgranulin B/genetics , NFATC Transcription Factors/metabolism , NFATC Transcription Factors/genetics , Fibroblast Growth Factor-23/metabolism , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology , Signal Transduction , Cardiomegaly/metabolism , Cardiomegaly/pathology , Mice, Inbred C57BL , Male , Mice, Knockout , Calcineurin/metabolism , Mice , Hypertrophy, Left Ventricular/metabolism , Hypertrophy, Left Ventricular/physiopathology , Hypertrophy, Left Ventricular/genetics , Hypertrophy, Left Ventricular/pathology , Ventricular Remodeling
11.
Pharmacol Res ; 205: 107230, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38788820

ABSTRACT

Immune checkpoint inhibitors (ICIs) are essential for urothelial carcinoma (UC) treatment. Fibroblast growth factor receptor (FGFR) alterations, as common oncogenic drivers in UC, have been reported to drive T cell depletion of UC immune microenvironment via up-regulating FGFR signaling, which indicated FGFR alterations potentially result in reduced response to ICIs. In addition, the selective pan-FGFR inhibitor showed better clinical benefit in clinical trials, indicating FGFR has emerged as critical therapeutic target via inhibiting FGFR signaling. The present study aims to evaluate prognosis and response to ICIs between FGFR-altered UC patients and FGFR-wildtype UC patients via 1963 UC patients and offers new insights into personalized precision therapy and combination therapy for UC.


Subject(s)
Immune Checkpoint Inhibitors , Receptors, Fibroblast Growth Factor , Humans , Immune Checkpoint Inhibitors/therapeutic use , Receptors, Fibroblast Growth Factor/antagonists & inhibitors , Immunotherapy/methods , Urinary Bladder Neoplasms/drug therapy , Urinary Bladder Neoplasms/immunology , Urologic Neoplasms/drug therapy , Urologic Neoplasms/immunology , Prognosis , Female , Male , Carcinoma, Transitional Cell/drug therapy , Carcinoma, Transitional Cell/immunology
12.
World J Hepatol ; 16(4): 490-493, 2024 Apr 27.
Article in English | MEDLINE | ID: mdl-38689741

ABSTRACT

Cancer immunotherapy is administered for first-line, second-line, neoadjuvant, or adjuvant treatment of advanced, metastatic, and recurrent cancer in the liver, gastrointestinal tract, and genitourinary tract, and other solid tumors. Erdafitinib is a fibroblast growth factor receptor (FGFR) inhibitor, and it is an adenosine triphosphate competitive inhibitor of FGFR1, FGFR2, FGFR3, and FGFR4. Immune checkpoint inhibitors are monoclonal antibodies that block programmed cell death protein 1 (PD-1) and its ligand that exert intrinsic antitumor mechanisms. The promising results of first-line treatment of advanced and metastatic urothelial carcinoma with PD-1 blockades with single or combined agents, indicate a new concept in the treatment of advanced, metastatic, and recurrent hepatic and gastrointestinal carcinomas. Cancer immunotherapy as first-line treatment will improve overall survival and provide better quality of life. Debate is arising as to whether to apply the cancer immunotherapy as first-line treatment in invasive carcinomas, or as second-line treatment in recurrent or metastatic carcinoma following the standard chemotherapy. The literature in the field is not definite, and so far, there has been no consensus on the best approach in this situation. At present, as it is described in this editorial, the decision is applied on a case-by-case basis.

13.
Anim Cells Syst (Seoul) ; 28(1): 216-227, 2024.
Article in English | MEDLINE | ID: mdl-38770056

ABSTRACT

Tyrosine kinase inhibitors (TKIs) have emerged as a potential treatment strategy for glioblastoma multiforme (GBM). However, their efficacy is limited by various drug resistance mechanisms. To devise more effective treatments for GBM, genetic characteristics must be considered in addition to pre-existing treatments. We performed an integrative analysis with heterogeneous GBM datasets of genomic, transcriptomic, and proteomic data from DepMap, TCGA and CPTAC. We found that poor prognosis was induced by co-upregulation of heat shock protein family A member 5 (HSPA5) and fibroblast growth factor receptor 1 (FGFR1). Co-up regulation of these two genes could regulate the PI3K/AKT pathway. GBM cell lines with co-upregulation of these two genes showed higher drug sensitivity to PI3K inhibitors. In the mesenchymal subtype, the co-upregulation of FGFR1 and HSPA5 resulted in the most malignant subtype of GBM. Furthermore, we found this newly discovered subtype was correlated with homologous recombination deficiency (HRD) In conclusion, we discovered novel druggable candidates within the group exhibiting co-upregulation of these two genes in GBM, suggest potential strategies for combination therapy.

14.
Cell Commun Signal ; 22(1): 225, 2024 Apr 11.
Article in English | MEDLINE | ID: mdl-38605348

ABSTRACT

The endothelial glycocalyx, located at the luminal surface of the endothelium, plays an important role in the regulation of leukocyte adhesion, vascular permeability, and vascular homeostasis. Endomucin (EMCN), a component of the endothelial glycocalyx, is a mucin-like transmembrane glycoprotein selectively expressed by venous and capillary endothelium. We have previously shown that knockdown of EMCN impairs retinal vascular development in vivo and vascular endothelial growth factor 165 isoform (VEGF165)-induced cell migration, proliferation, and tube formation by human retinal endothelial cells in vitro and that EMCN is essential for VEGF165-stimulated clathrin-mediated endocytosis and signaling of VEGF receptor 2 (VEGFR2). Clathrin-mediated endocytosis is an essential step in receptor signaling and is of paramount importance for a number of receptors for growth factors involved in angiogenesis. In this study, we further investigated the molecular mechanism underlying EMCN's involvement in the regulation of VEGF-induced endocytosis. In addition, we examined the specificity of EMCN's role in angiogenesis-related cell surface receptor tyrosine kinase endocytosis and signaling. We identified that EMCN interacts with AP2 complex, which is essential for clathrin-mediated endocytosis. Lack of EMCN did not affect clathrin recruitment to the AP2 complex following VEGF stimulation, but it is necessary for the interaction between VEGFR2 and the AP2 complex during endocytosis. EMCN does not inhibit VEGFR1 and FGFR1 internalization or their downstream activities since EMCN interacts with VEGFR2 but not VEGFR1 or FGFR1. Additionally, EMCN also regulates VEGF121-induced VEGFR2 phosphorylation and internalization.


Subject(s)
Endothelial Cells , Vascular Endothelial Growth Factor A , Humans , Endothelial Cells/metabolism , Vascular Endothelial Growth Factor A/metabolism , Vascular Endothelial Growth Factor Receptor-2/metabolism , Sialomucins/metabolism , Endocytosis , Clathrin/metabolism
15.
Acta Pharm Sin B ; 14(4): 1605-1623, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38572102

ABSTRACT

Immune-mediated liver injury (ILI) is a condition where an aberrant immune response due to various triggers causes the destruction of hepatocytes. Fibroblast growth factor 4 (FGF4) was recently identified as a hepatoprotective cytokine; however, its role in ILI remains unclear. In patients with autoimmune hepatitis (type of ILI) and mouse models of concanavalin A (ConA)- or S-100-induced ILI, we observed a biphasic pattern in hepatic FGF4 expression, characterized by an initial increase followed by a return to basal levels. Hepatic FGF4 deficiency activated the mitochondria-associated intrinsic apoptotic pathway, aggravating hepatocellular apoptosis. This led to intrahepatic immune hyper-reactivity, inflammation accentuation, and subsequent liver injury in both ILI models. Conversely, administration of recombinant FGF4 reduced hepatocellular apoptosis and rectified immune imbalance, thereby mitigating liver damage. The beneficial effects of FGF4 were mediated by hepatocellular FGF receptor 4, which activated the Ca2+/calmodulin-dependent protein kinasekinase 2 (CaMKKß) and its downstream phosphatase and tensin homologue-induced putative kinase 1 (PINK1)-dependent B-cell lymphoma 2-like protein 1-isoform L (Bcl-XL) signalling axis in the mitochondria. Hence, FGF4 serves as an early response factor and plays a protective role against ILI, suggesting a therapeutic potential of FGF4 and its analogue for treating clinical immune disorder-related liver injuries.

16.
Endocr J ; 2024 Apr 04.
Article in English | MEDLINE | ID: mdl-38569854

ABSTRACT

Achondroplasia (ACH) is a representative skeletal disorder characterized by rhizomelic shortened limbs and short stature. ACH is classified as belonging to the fibroblast growth factor receptor 3 (FGFR3) group. The downstream signal transduction of FGFR3 consists of STAT1 and RAS/RAF/MEK/ERK pathways. The mutant FGFR3 found in ACH is continuously phosphorylated and activates downstream signals, resulting in abnormal proliferation and differentiation of chondrocytes in the growth plate and cranial base synchondrosis. A patient registry has been developed and has contributed to revealing the natural history of ACH patients. Concerning the short stature, the adult height of ACH patients ranges between 126.7-135.2 cm for men and 119.9-125.5 cm for women in many countries. Along with severe short stature, foramen magnum stenosis and spinal canal stenosis are major complications: the former leads to sleep apnea, breathing disorders, myelopathy, hydrocephalus, and sudden death, and the latter causes pain in the extremities, numbness, muscle weakness, movement disorders, intermittent claudication, and bladder-rectal disorders. Growth hormone treatment is available for ACH only in Japan. However, the effect of the treatment on adult height is not satisfactory. Recently, the neutral endopeptidase-resistant CNP analogue vosoritide has been approved as a new drug for ACH. Additionally in development are a tyrosine kinase inhibitor, a soluble FGFR3, an antibody against FGFR3, meclizine, and the FGF2-aptamer. New drugs will bring a brighter future for patients with ACH.

17.
J Clin Med ; 13(5)2024 Feb 25.
Article in English | MEDLINE | ID: mdl-38592174

ABSTRACT

Background: Mutations of fibroblast growth factor receptor 3 (FGFR3) are associated with urothelial carcinoma (UC) oncogenesis and are considered an important therapeutic target. Therefore, we evaluated the FGFR3 mutation rate and its clinical significance in urothelial carcinoma (UC) using next-generation sequencing. Methods: A total of 123 patients with UC who were treated at Chonnam National University Hospital (Gwang-ju, Korea) from January 2018 to December 2020 were enrolled. We performed NGS using the Oncomine panel with tumor specimens and blood samples corresponding to each specimen. We analyzed the FGFR3 mutation results according to the type of UC and the effects on early recurrence and progression. Results: The mean age of the patients was 71.39 ± 9.33 years, and 103 patients (83.7%) were male. Overall, the FGFR3 mutation rate was 30.1% (37 patients). The FGFR3 mutation rate was the highest in the non-muscle-invasive bladder cancer (NMIBC) group (45.1%), followed by the muscle-invasive bladder cancer (22.7%) and upper tract UC (UTUC) (14.3%) groups. Patients with FGFR3 mutations had a significantly lower disease stage (p = 0.019) but a high-risk of NMIBC (p < 0.001). Conclusions: Our results revealed that FGFR3 mutations were more prevalent in patients with NMIBC and lower stage UC and associated with a high-risk of NMIBC. Large multicenter studies are needed to clarify the clinical significance of FGFR3 mutations in UC.

19.
Front Endocrinol (Lausanne) ; 15: 1379231, 2024.
Article in English | MEDLINE | ID: mdl-38638139

ABSTRACT

Receptor tyrosine kinases (RTKs) mediate the actions of growth factors in metazoans. In decapod crustaceans, RTKs are implicated in various physiological processes, such molting and growth, limb regeneration, reproduction and sexual differentiation, and innate immunity. RTKs are organized into two main types: insulin receptors (InsRs) and growth factor receptors, which include epidermal growth factor receptor (EGFR), fibroblast growth factor receptor (FGFR), vascular endothelial growth factor receptor (VEGFR), and platelet-derived growth factor receptor (PDGFR). The identities of crustacean RTK genes are incomplete. A phylogenetic analysis of the CrusTome transcriptome database, which included all major crustacean taxa, showed that RTK sequences segregated into receptor clades representing InsR (72 sequences), EGFR (228 sequences), FGFR (129 sequences), and PDGFR/VEGFR (PVR; 235 sequences). These four receptor families were distinguished by the domain organization of the extracellular N-terminal region and motif sequences in the protein kinase catalytic domain in the C-terminus or the ligand-binding domain in the N-terminus. EGFR1 formed a single monophyletic group, while the other RTK sequences were divided into subclades, designated InsR1-3, FGFR1-3, and PVR1-2. In decapods, isoforms within the RTK subclades were common. InsRs were characterized by leucine-rich repeat, furin-like cysteine-rich, and fibronectin type 3 domains in the N-terminus. EGFRs had leucine-rich repeat, furin-like cysteine-rich, and growth factor IV domains. N-terminal regions of FGFR1 had one to three immunoglobulin-like domains, whereas FGFR2 had a cadherin tandem repeat domain. PVRs had between two and five immunoglobulin-like domains. A classification nomenclature of the four RTK classes, based on phylogenetic analysis and multiple sequence alignments, is proposed.


Subject(s)
Furin , Insulin , Furin/genetics , Phylogeny , Insulin/genetics , Transcriptome , Cysteine , Leucine/genetics , Vascular Endothelial Growth Factor A/genetics , Receptor Protein-Tyrosine Kinases/genetics , Receptor Protein-Tyrosine Kinases/metabolism , ErbB Receptors/metabolism , Receptors, Fibroblast Growth Factor/genetics , Receptors, Fibroblast Growth Factor/metabolism , Gene Expression Profiling , Tyrosine
20.
Int J Mol Sci ; 25(8)2024 Apr 20.
Article in English | MEDLINE | ID: mdl-38674107

ABSTRACT

The fibroblast growth factor receptor 2 (FGFR2) gene is one of the most extensively studied genes with many known mutations implicated in several human disorders, including oncogenic ones. Most FGFR2 disease-associated gene mutations are missense mutations that result in constitutive activation of the FGFR2 protein and downstream molecular pathways. Many tertiary structures of the FGFR2 kinase domain are publicly available in the wildtype and mutated forms and in the inactive and activated state of the receptor. The current literature suggests a molecular brake inhibiting the ATP-binding A loop from adopting the activated state. Mutations relieve this brake, triggering allosteric changes between active and inactive states. However, the existing analysis relies on static structures and fails to account for the intrinsic structural dynamics. In this study, we utilize experimentally resolved structures of the FGFR2 tyrosine kinase domain and machine learning to capture the intrinsic structural dynamics, correlate it with functional regions and disease types, and enrich it with predicted structures of variants with currently no experimentally resolved structures. Our findings demonstrate the value of machine learning-enabled characterizations of structure dynamics in revealing the impact of mutations on (dys)function and disorder in FGFR2.


Subject(s)
Receptor, Fibroblast Growth Factor, Type 2 , Receptor, Fibroblast Growth Factor, Type 2/genetics , Receptor, Fibroblast Growth Factor, Type 2/chemistry , Receptor, Fibroblast Growth Factor, Type 2/metabolism , Humans , Mutation , Machine Learning , Mutation, Missense , Models, Molecular , Protein Conformation , Protein Domains , Structure-Activity Relationship
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