Fibroblast Growth Factor Receptor Signaling Research Articles

Critical Role of CD55 in Controlling Wound Healing.

How reparative processes are coordinated following injury is incompletely understood. In recent studies, we showed that autocrine C3a and C5a receptor (C3ar1 and C5ar1) G protein-coupled receptor signaling plays an obligate role in vascular endothelial growth factor receptor 2 growth signaling in vascular endothelial cells. We documented the same interconnection for platelet-derived growth factor receptor growth signaling in smooth muscle cells, epidermal growth factor receptor growth signaling in epidermal cells, and fibroblast growth factor receptor signaling in fibroblasts, indicative of a generalized cell growth regulatory mechanism. In this study, we examined one physiological consequence of this signaling circuit. We found that disabling CD55 (also known as decay accelerating factor), which lifts restraint on autocrine C3ar1/C5ar1 signaling, concomitantly augments the growth of each cell type. The mechanism is heightened C3ar1/C5ar1 signaling resulting from the loss of CD55's restraint jointly potentiating growth factor production by each cell type. Examination of the effect of lifted CD55 restraint in four types of injury (burn, corneal denudation, ear lobe puncture, and reengraftment of autologous skin) showed that disabled CD55 function robustly accelerated healing in all cases, whereas disabled C3ar1/C5ar1 signaling universally retarded it. In wild-type mice with burns or injured corneas, applying a mouse anti-mouse CD55 blocking Ab (against CD55's active site) to wounds accelerated the healing rate by 40-70%. To our knowledge, these results provide new insights into mechanisms that underlie wound repair and open up a new tool for accelerating healing.

Abstract B066: PDGFR upregulation functions as a bypass mechanism contributing to FGFR inhibitor resistance in metastatic breast cancer

Abstract Breast cancer (BC) is the most diagnosed cancer in females in the United States and the second leading cause of cancer related deaths among women. The fibroblast growth factor receptor (FGFR) signaling pathway is frequently activated in BC, making it an attractive therapeutic target, especially in metastatic disease. However, clinical trials using FGFR inhibitors in BC have been disappointing in comparison to other cancer types treated with these therapies. As a result, BC patients with activated FGFR do not have a targeted therapeutic option. Failure of FGFR inhibitors is indicative of intrinsic or acquired resistance mechanisms in metastatic BC. Herein we demonstrate significant efficacy of the FGFR inhibitor, pemigatinib, in the 4T07 murine model of BC utilizing a tail vein model to induce pulmonary tumors. Despite this initial response, pemigatinib fails to eliminate minimal residual disease (MRD) and allows for accelerated tumor return after pemigatinib cessation. Characterizing the MRD by IHC following pemigatinib treatment shows that expression of platelet-derived growth factor receptor (PDGFR) is significantly increased on tumor cells. This rise in PDGFR expression following pemigatinib treatment increases the responsiveness of 4T07 cells to platelet-derived growth factor ligand indicating PDGFR may act as an alternate signaling pathway bypassing FGFR signaling. Mechanistically, previous studies indicate that PDGFR protein expression is transcriptionally repressed by restriction of enhancer positioning by the CTCF insulator. DNA methylation surrounding CTCF causes its dissociation enhancing protein expression of PDGFR. Along these lines cotreatment with a DNA methyl transferase inhibitor prevents the increase of PDGFR protein expression induced by pemigatinib. Overall, our study determined that a highly potent FGFR inhibitor can inhibit tumor growth in a metastatic site, but it fails to eliminate MRD giving rise to tumor recurrence. Upregulation of PDGFR may act as a bypass mechanism of resistance allowing for tumor cell survival during pemigatinib treatment. Finally, our findings suggest that dual inhibition of DNA methylation and FGFR could improve patient response in metastatic BC. Citation Format: Mitchell Ayers, Michael Wendt. PDGFR upregulation functions as a bypass mechanism contributing to FGFR inhibitor resistance in metastatic breast cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr B066.

The efficacy and safety of tinengotinib in patients with heavily pretreated metastatic castration-resistant prostate cancer (mCRPC).

133 Background: Tinengotinib is a spectrum-selective multi-kinase inhibitor that targets cell proliferation, angiogenesis, and immune-oncology pathways by inhibiting Aurora kinases A/B, Janus kinases (JAK), and receptor tyrosine kinases (FGFRs, VEGFRs). It has been reported that the activation of JAK/STAT and fibroblast growth factor receptor (FGFR) signaling drives prostate tumor plasticity. Here we present the preliminary safety and efficacy data of tinengotinib in patients with mCRPC from three early phase clinical trials conducted in the US and China. Methods: Eligible mCRPC patients who have no available standard therapeutic treatment options were enrolled to the three studies. Tinengotinib was given as monotherapy at 8 mg QD, 10 mg QD and 12 mg QD. Efficacy tumor assessments were based on RECIST v1.1 for measurable disease and Prostate Cancer Working Group 3 criteria for non-measurable (bone) disease. PSA50 response was also evaluated. CTCAE v5.0 was used for safety assessments. Results: As of 28AUG2023, 30 patients with mCRPC were treated at dose levels of 8 mg QD (n=1), 10 mg QD (n=19) and 12 mg QD (n=10). Median age was 67 years (range 52-82) with ECOG performance status of 1 in 93% of patients. All patients had at least 2 prior therapies including 77% prior docetaxel, 87% prior abiraterone, and 30% prior enzalutamide. The median follow-up time is 5.4 months. Twenty-two (22) patients were efficacy evaluable, of which 13 were evaluable per RECIST v1.1. Fourteen (14) patients were PSA evaluable. The median radiographic progression-free survival (rPFS) was 5.6 months (95% CI, 3.3-7.3). Overall response rate (ORR) was 46% (6/13) and the disease control rate (DCR) was 85% (11/13). Median duration of response (DoR) was 3.0 months. The PSA50 response rate was 50% (7/14). Treatment-related adverse events (TRAEs) occurred in 28 patients (93%). The most common TRAEs (≥20%) included blood thyroid stimulating hormone increase (43%), anemia (37%), hypertension (27%), aspartate aminotransferase increase (23%), electrocardiogram QT prolongation (20%) and white blood cell count decrease (20%). Conclusions: Tinengotinib safety profile was tolerable and manageable. The preliminary efficacy data showed promising clinical benefit of tinengotinib monotherapy in patients with heavily pretreated mCRPC. Further study of tinengotinib in this disease is warranted. Clinical trial information: NCT03654547 , NCT04742959 , NCT05253053 .

Identification of Piperazinyl-Difluoro-indene Derivatives Containing Pyridyl Groups as Potent FGFR Inhibitors against FGFR Mutant Tumor: Design, Synthesis, and Biological Evaluation.

The fibroblast growth factor receptor (FGFR) signaling pathway plays important roles in cellular processes such as proliferation, differentiation, and migration. In this study, we highlighted the potential of FGFR inhibitors bearing the (S)-3,3-difluoro-1-(4-methylpiperazin-1-yl)-2,3-dihydro-1H-indene scaffold containing a crucial 3-pyridyl group for the treatment of FGFR mutant cancers. The representative compound (S)-23, which was identified through comprehensive evaluation, exhibited potent antiproliferative activity with GI50 in the range of 6.4-10.4 nM against FGFR1 fusion protein-carrying, FGFR2-amplified, and FGFR2 mutant cancer cell lines and good antiproliferative activity against FGFR3 translocation and mutant FGFR4 cancer cell lines, as well as potency assessment against FGFR1-4 kinases. Moreover, compound (S)-23 exhibited favorable pharmacokinetic properties, low potential for drug-drug interactions, and very potent antitumor activity in MFE-296 xenograft mouse models with a TGI of 99.1% at the dose of 10 mg/kg. These findings demonstrate that compound (S)-23 is a potential therapeutic agent for FGFR mutant tumors.

Preclinical characterization of CPL304110 as a potent and selective inhibitor of fibroblast growth factor receptors 1, 2, and 3 for gastric, bladder, and squamous cell lung cancer.

Fibroblast Growth Factor Receptors (FGFRs) are a family of receptor tyrosine kinases expressed on a plethora of cell membranes. They play crucial roles in both embryonic development and adult tissue functions. There is an increasing amount of evidence that FGFR-mediated oncogenesis is mainly related to gene amplification, activating mutations, or translocation in tumors of various histological types. Dysregulation of FGFRs has been implicated in a wide variety of neoplasms, such as bladder, gastric, and lung cancers. Given their functional significance, FGFRs emerge as promising targets for cancer therapy. Here, we introduce CPL304100, an innovative and highly potent FGFR1-3 kinase inhibitor demonstrating excellent in vitro biological activity. Comprehensive analyses encompassed kinase assays, cell line evaluations, PK/PD studies surface plasmon resonance studies, molecular docking, and in vivo testing in mouse xenografts. CPL304110 exhibited a distinctive binding profile to FGFR1/2/3 kinase domains, accompanied by a good safety profile and favorable ADMET parameters. Selective inhibition of tumor cell lines featuring active FGFR signaling was observed, distinguishing it from cell lines lacking FGFR aberrations (FGFR1, 2, and 3). CPL304110 demonstrated efficacy in both FGFR-dependent cell lines and patient-derived tumor xenograft (PDTX) in vivo models. Comparative analyses with FDA-approved FGFR inhibitors, erdafitinib and pemigatinib, revealed certain advantages of CPL304110 in both in vitro and in vivo assessments. Encouraging preclinical results led the way for the initiation of a Phase I clinical trial (01FGFR2018; NCT04149691) to further evaluate CPL304110 as a novel anticancer therapy.

Dual FGFR-targeting and pH-activatable ruthenium-peptide conjugates for targeted therapy of breast cancer.

Dysregulation of Fibroblast Growth Factor Receptors (FGFRs) signaling has been associated with breast cancer, yet employing FGFR-targeted delivery systems to improve the efficacy of cytotoxic agents is still sparsely exploited. Herein, we report four new bi-functional ruthenium-peptide conjugates (RuPCs) with FGFR-targeting and pH-dependent releasing abilities, envisioning the selective delivery of cytotoxic Ru complexes to FGFR(+)-breast cancer cells, and controlled activation at the acidic tumoral microenvironment. The antiproliferative potential of the RuPCs and free Ru complexes was evaluated in four breast cancer cell lines with different FGFR expression levels (SKBR-3, MDA-MB-134-VI, MCF-7, and MDA-MB-231) and in human dermal fibroblasts (HDF), at pH 6.8 and pH 7.4 aimed at mimicking the tumor microenvironment and normal tissues/bloodstream pHs, respectively. The RuPCs showed higher cytotoxicity in cells with higher level of FGFR expression at acidic pH. Additionally, RuPCs showed up to 6-fold higher activity in the FGFR(+) breast cancer lines compared to the normal cell line. The release profile of Ru complexes from RuPCs corroborates the antiproliferative effects observed. Remarkably, the cytotoxicity and releasing ability of RuPCs were shown to be strongly dependent on the conjugation of the peptide position in the Ru complex. Complementary molecular dynamic simulations and computational calculations were performed to help interpret these findings at the molecular level. In summary, we identified a lead bi-functional RuPC that holds strong potential as a FGFR-targeted chemotherapeutic agent.

Investigation of Conserved Amino Acids in the EGL-15 5A Domain Required for Sex Myoblast Migration in C. elegans.

Fibroblast Growth Factor Receptors (FGFRs) play a role in diverse developmental pathways that mediate cell proliferation, cell migration, and cell survival. We use C. elegans as a model to better understand FGFR signaling specificity. C. elegans has a single FGFR, EGL-15 . EGL-15 contains an alternatively spliced exon 5 that results in two isoforms, EGL-15(5A) and EGL-15(5B), that differ in their extracellular domains. The EGL-15(5A) isoform is required for the chemoattraction of a pair of migrating sex myoblasts, whose correct positioning is required for egg laying. Deletion of the 5A domain results in an egg-laying defective (Egl) organism. We identified six highly conserved amino acids within the 5A domain and found that two amino acids, S145 and L148 are specifically required for sex myoblast migration in C. elegans .

DDIT3 is associated with breast cancer prognosis and immune microenvironment: an integrative bioinformatic and immunohistochemical analysis.

DNA damage-inducible transcript 3 (DDIT3) is a transcription factor central to apoptosis, differentiation, and stress response. DDIT3 has been extensively studied in cancer biology. However, its precise implications in breast cancer progression and its interaction with the immune microenvironment are unclear. In this study, we utilized a novel multi-omics integration strategy, combining bulk RNA sequencing, single-cell sequencing, spatial transcriptomics and immunohistochemistry, to explore the role of DDIT3 in breast cancer and establish the correlation between DDIT3 and poor prognosis in breast cancer patients. We identified a robust prognostic signature, including six genes (unc-93 homolog B1, TLR signaling regulator, anti-Mullerian hormone, DCTP pyrophosphatase 1, mitochondrial ribosomal protein L36, nuclear factor erythroid 2, and Rho GTPase activating protein 39), associated with DDIT3. This signature stratified the high-risk patient groups, characterized by increased infiltration of the regulatory T cells and M2-like macrophages and fibroblast growth factor (FGF)/FGF receptor signaling activation. Notably, the high-risk patient group demonstrated enhanced sensitivity to immunotherapy, presenting novel therapeutic opportunities. Integrating multi-omics data helped determine the spatial expression pattern of DDIT3 in the tumor microenvironment and its correlation with immune cell infiltration. This multi-dimensional analysis provided a comprehensive understanding of the intricate interplay between DDIT3 and the immune microenvironment in breast cancer. Overall, our study not only facilitates understanding the role of DDIT3 in breast cancer but also offers innovative insights for developing prognostic models and therapeutic strategies. Identifying the DDIT3-related prognostic signature and its association with the immune microenvironment provided a promising avenue for personalized breast cancer treatment.

Molecular features of gastrointestinal stromal tumors “wild-type” (<i>KIT/PDGFRA</i> WT)

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. Their main features are the expression of CD117 (KIT) and mutations of KIT or PDGFRA in 85 % of patients. however, 10–15 % of adult GIST and 85 % of pediatric GIST do not have KIT/PDGFRA mutations (KIT/PDGFRA WT GIST or “wild-type” GIST). The prognosis and clinical course of these tumors and GIST with KIT/PDGFRA mutations differ. “Wild-type” GIST are quite heterogeneous group of tumors in terms of clinical phenotype, genetic etiology, and molecular pathways. Gastrointestinal stromal tumors are divided into SDH-deficient and SDH-competent based on the succinate dehydrogenase (SDH) complex. SDH-deficient GIST occur predominantly in children and young patients with Carney–Stratakis syndrome and Carney triad; there are also sporadic tumors. More than half of SDH-deficient GIST contain mutations in SDHA, SDHB, SDHD or SDHC, while the rest are caused by hypermethylation of the SDHC promoter. SDH-competent “wild-type” GIST include tumors with BRAF, RAS, or NF1 mutations that activate the RAS-RAF-MAPK pathway and KIT/PDGFRA/SDH/RAS-P WT GIST subtype or “quadruple wild type” GIST. The genomic profiles of these tumors and GIST with KIT/PDGFRA mutation or SDH deficiency differ significantly. One of the features of “quadruple wild type” GIST is activation of the FGFR (fibroblast growth factor receptors) signaling pathway due to chimeric FGFR, FGFR mutations, or overexpression of FGF (fibroblast growth factor). Another feature is chimeric genes containing fragments of NTRK, BRAF, FGFR and other genes that behave as oncogene drivers. In “quadruple wild-type” GIST the somatic mutations in TP53, MAX, MEN1, CTNND2, CHD4, ARIDIA and other genes were revealed as well as in the cell cycle genes RB1, CDK4, CDKN1B. There is no specific treatment for patients with “wild-type” GIST; the choice of drug is determined by the genetic disorder. There is a need to improve our understanding of the molecular mechanisms underlying the different GIST subtypes to develop more effective therapeutic approaches.

Cell-based screen identifies porphyrins as FGFR3 activity inhibitors with therapeutic potential for achondroplasia and cancer.

Overactive fibroblast growth factor receptor 3 (FGFR3) signaling drives pathogenesis in a variety of cancers and a spectrum of short-limbed bone dysplasias, including the most common form of human dwarfism, achondroplasia (ACH). Targeting FGFR3 activity holds great promise as a therapeutic approach for treatment of these diseases. Here, we established a receptor/adaptor translocation assay system that can specifically monitor FGFR3 activation, and we applied it to identify FGFR3 modulators from complex natural mixtures. An FGFR3-suppressing plant extract of Amaranthus viridis was identified from the screen, and 2 bioactive porphyrins, pheophorbide a (Pa) and pyropheophorbide a, were sequentially isolated from the extract and functionally characterized. Further analysis showed that Pa reduced excessive FGFR3 signaling by decreasing its half-life in FGFR3-overactivated multiple myeloma cells and chondrocytes. In an ex vivo culture system, Pa alleviated defective long bone growth in humanized ACH mice (FGFR3ACH mice). Overall, our study presents an approach to discovery and validation of plant extracts or drug candidates that target FGFR3 activation. The compounds identified by this approach may have applications as therapeutics for FGFR3-associated cancers and skeletal dysplasias.

Screening and identification of hub genes of scar physique via weighted gene co-expression network analysis.

Scar physique refers to the abnormal repair of skin injury in some people, which may easily lead to keloid or hypertrophic scar. However, the mechanism of scar physique is still unclear. GSE108110 was obtained from the gene expression omnibus database. Differently expression genes (DEGs) between normal skin tissue of non-scar physique individuals and normal skin tissue of scar physique individuals were screened by R package "limma". Weighted gene co-expression network analysis was performed to find highly relevant gene modules. Functional annotation of DEGs was made. Protein-protein interaction network was constructed, and the identification and analysis of hub DEGs were performed, including identification of hub DEGs associated with scar diseases, MiRNA of hub DEGs prediction, and functional annotation of miRNA. A total of 1389 up-regulate DEGs and 1672 down-regulate DEGs were screened. weighted gene co-expression network analysis analysis showed that the dendrogram and heatmap were used to quantify module similarity by correlation. The associations between clinic traits and the modules were identified based on the correlation between module and scar physique. Eight common hub genes were obtained. The comparative toxicogenomics database shows common hub genes associated with scar tissue. Gene ontology and Kyoto encyclopedia of genes and genomes analysis were significantly enriched in "fibroblast growth factor receptor signaling pathway", "epidermal growth factor receptor signaling pathway", "G1/S transition of mitotic cell cycle", protein polyubiquitination", and others. The 8 hub genes might be involved in the development of scarring and used as early diagnosis, prevention and treatment of scar physique.

FGFR blockade inhibits targeted therapy-tolerant persister in basal FGFR1- and FGF2-high cancers with driver oncogenes

Cancer cell resistance arises when tyrosine kinase inhibitor (TKI)-targeted therapies induce a drug-tolerant persister (DTP) state with growth via genetic aberrations, making DTP cells potential therapeutic targets. We screened an anti-cancer compound library and identified fibroblast growth factor receptor 1 (FGFR1) promoting alectinib-induced anaplastic lymphoma kinase (ALK) fusion-positive DTP cell’s survival. FGFR1 signaling promoted DTP cell survival generated from basal FGFR1- and fibroblast growth factor 2 (FGF2)-high protein expressing cells, following alectinib treatment, which is blocked by FGFR inhibition. The hazard ratio for progression-free survival of ALK-TKIs increased in patients with ALK fusion-positive non-small cell lung cancer with FGFR1- and FGF2-high mRNA expression at baseline. The combination of FGFR and targeted TKIs enhanced cell growth inhibition and apoptosis induction in basal FGFR1- and FGF2-high protein expressing cells with ALK-rearranged and epidermal growth factor receptor (EGFR)-mutated NSCLC, human epidermal growth factor receptor 2 (HER2)-amplified breast cancer, or v-raf murine sarcoma viral oncogene homolog B1 (BRAF)-mutated melanoma by preventing compensatory extracellular signal-regulated kinase (ERK) reactivation. These results suggest that a targeted TKI-induced DTP state results from an oncogenic switch from activated oncogenic driver signaling to the FGFR1 pathway in basal FGFR1- and FGF2-high expressing cancers and initial dual blockade of FGFR and driver oncogenes based on FGFR1 and FGF2 expression levels at baseline is a potent treatment strategy to prevent acquired drug resistance to targeted TKIs through DTP cells regardless of types of driver oncogenes.

Fibroblast growth factor inhibition by molecular-targeted agents mitigates immunosuppressive tissue microenvironment in hepatocellular carcinoma

Background & aimsCombination immunotherapy refers to the use of immune checkpoint inhibitors (ICI) and molecular-targeted agents (MTA), which have recently been approved for the treatment of advanced hepatocellular carcinoma (HCC). Owing to its relatively low antitumor effect (up to 30%), sequential therapy following ICIs treatment is required in patients with HCC. This study aimed to determine the impact of MTAs on the tumor immune microenvironment (TIME).MethodsWe established immune syngeneic orthotopic HCC mouse models using Hep-55.1C and Hep-53.4, and treated them with MTAs (lenvatinib, sorafenib, regorafenib, cabozantinib, and DC101 as anti-vascular endothelial growth factor receptor-2 antibodies, and AZD4547 as a fibroblast growth factor receptor (FGFR)-1/2/3/4 inhibitor) for 2 weeks. Subsequently, alterations in the TIME caused by MTAs were evaluated using immunohistochemistry (antibodies for CD3, CD8, Foxp3, Granzyme B, Arginase-1, NK1.1, F4/80, CD11c, PD-1, and PD-L1). We conducted RNA-seq analysis using lenvatinib- and AZD4547-treated tumors. To confirm the clinical relevance of these findings, we analyzed the transcriptome data of human HCC cells (MHCC-97H) treated with various concentrations of lenvatinib for 24 h using RNA-seq data from the Gene Expression Omnibus database.ResultsThe number of Foxp3- and F4/80-positive cells in the TIME was decreased in many MTAs. Cabozantinib increased the numbers in NK1.1-, Granzyme B, and CD11c-positive cells. Lenvatinib and AZD4547 increased the number of CD8, Granzyme B, and PD-L1-positive cells. Gene ontology enrichment analysis revealed that lipid metabolism-related genes were downregulated by lenvatinib and AZD4547. In total, 161 genes downregulated by FGFR inhibition in rodent models overlapped with those downregulated by lenvatinib in human HCC cells.ConclusionsIn this study, we showed that cabozantinib activated the innate immune system, and lenvatinib and AZD4547, which commonly inhibit FGFR signaling, altered TIME to a hot immune state by downregulating lipid metabolism-related genes. These findings support the therapeutic use of combination immunotherapies.

FGFR2 is essential for salivary gland duct homeostasis and MAPK-dependent seromucous acinar cell differentiation

Exocrine acinar cells in salivary glands (SG) are critical for oral health and loss of functional acinar cells is a major clinical challenge. Fibroblast growth factor receptors (FGFR) are essential for early development of multiple organs, including SG. However, the role of FGFR signaling in specific populations later in development and during acinar differentiation are unknown. Here, we use scRNAseq and conditional deletion of murine FGFRs in vivo to identify essential roles for FGFRs in craniofacial, early SG development and progenitor function during duct homeostasis. Importantly, we also discover that FGFR2 via MAPK signaling is critical for seromucous acinar differentiation and secretory gene expression, while FGFR1 is dispensable. We show that FGF7, expressed by myoepithelial cells (MEC), activates the FGFR2-dependent seromucous transcriptional program. Here, we propose a model where MEC-derived FGF7 drives seromucous acinar differentiation, providing a rationale for targeting FGFR2 signaling in regenerative therapies to restore acinar function.

Targeting the fibroblast growth factor pathway in molecular subtypes of castration-resistant prostate cancer.

Androgen receptor (AR) pathway inhibition remains the cornerstone for prostate cancer therapies. However, castration-resistant prostate cancer (CRPC) tumors can resist AR signaling inhibitors through AR amplification and AR splice variants in AR-positive CRPC (ARPC), and conversion to AR-null phenotypes, such as double-negative prostate cancer (DNPC) and small cell or neuroendocrine prostate cancer (SCNPC). We have shown previously that DNPC can bypass AR-dependence through fibroblast growth factor receptor (FGFR) signaling. However, the role of the FGFR pathway in other CRPC phenotypes has not been elucidated. RNA-Seq analysis was conducted on patient metastases, LuCaP patient-derived xenograft (PDX) models, and CRPC cell lines. Cell lines (C4-2B, VCaP, and 22Rv1) and ex vivo LuCaP PDX tumor cells were treated with enzalutamide (ENZA) and FGFR inhibitors (FGFRi) alone or in combination and sensitivity was determined using cell viability assays. In vivo efficacy of FGFRi in ARPC, DNPC, and SCNPC were evaluated using PDX models. RNA-Seq analysis of FGFR signaling in metastatic specimens, LuCaP PDX models, and CRPC cell lines revealed significant FGF pathway activation in AR-low PC (ARLPC), DNPC, and SCNPC tumors. In vitro/ex vivo analysis of erdafitinib and CH5183284 demonstrated robust and moderate growth suppression of ARPC, respectively. In vivo studies using four ARPC PDX models showed that combination ENZA and CH5183284 significantly suppressed tumor growth. Additional in vivo studies using four ARPC PDX models revealed that erdafitinib monotherapy was as effective as ENZA in suppressing tumor growth, and there was limited combination benefit. Furthermore, two of three DNPC models and two of four SCNPC models responded to CH5183284 monotherapy, suggesting FGFRi responses were model dependent. RNA-Seq and gene set enrichment analysis of end-of-study ARPC tumors treated with FGFRi displayed decreased expression of E2F and MYC target genes and suppressed G2M checkpoint genes, whereas end-of-study SCNPC tumors had heterogeneous transcriptional responses. Although FGFRi treatments suppressed tumor growth across CRPC phenotypes, our analyses did not identify a single pathway or biomarker that would identify tumor response to FGFRi. This is very likely due to the array of FGFR1-4 expression and tumor phenotypes present in CRPC. Nevertheless, our data nominate the FGFR pathway as a clinically actionable target that promotes tumor growth in diverse phenotypes of treatment-refractory metastatic CRPC.

Efficient improvement of the proliferation, differentiation, and anti-arthritic capacity of mesenchymal stem cells by simply culturing on the immobilized FGF2 derived peptide, 44-ERGVVSIKGV-53

IntroductionThe stem cell microenvironment has been evidenced to robustly affect its biological functions and clinical grade. Natural or synthetic growth factors, especially, are essential for modulating stem cell proliferation, metabolism, and differentiation via the interaction with specific extracellular receptors. Fibroblast growth factor-2 (FGF-2) possesses pleiotropic functions in various tissues and organs. It interacts with the FGF receptor (FGFR) and activates FGFR signaling pathways, which involve numerous biological functions, such as angiogenesis, wound healing, cell proliferation, and differentiation. ObjectivesHere, we aim to explore the molecular functions, mode of action, and therapeutic activity of yet undetermined function, FGF-2-derived peptide, FP2 (44-ERGVVSIKGV-53) in promoting the proliferation, differentiation, and therapeutic application of human Wharton’s jelly mesenchymal stem cells (hWJ-MSCs) in comparison to other test peptides, canofin1 (FP1), hexafin2 (FP3), and canofin3 (FP4) with known functions. MethodsThe immobilization of test peptides that are fused with mussel adhesive proteins (MAP) on the culture plate was carried out via EDC/NHS chemistry. Cell Proliferation assay, colony-forming unit, western blotting analysis, gene expression analysis, RNA-Seq. analysis, osteogenic, and chondrogenic differentiation capacity were applied to test the activity of the test peptides. We additionally utilized three-dimensional (3D) structural analysis and artificial intelligence (AI)-based AlphaFold2 and CABS-dock programs for receptor interaction prediction of the peptide receptor. We also verified the in vivo therapeutic capacity of FP2-cultured hWJ-MSCs using an osteoarthritis mice model. ResultsCulture of hWJ-MSC onto an FP2-immobilized culture plate showed a significant increase in cell proliferation (n = 3; *p < 0.05, **p < 0.01) and the colony-forming unit (n = 3; *p < 0.05, **p < 0.01) compared with the test peptides. FP2 showed a significantly upregulated phosphorylation of FRS2α and FGFR1 and activated the AKT and ERK signaling pathways (n = 3; *p < 0.05, **p < 0.01, ***p < 0.001). Interestingly, we detected efficient FP2 receptor binding that was predicted using AI-based tools. Treatment with an AKT inhibitor significantly abrogated the FP2-mediated enhancement of cell differentiation (n = 3; *p < 0.05, **p < 0.01, ***p < 0.001). Intra-articular injection of FP2-cultured MSCs significantly mitigated arthritis symptoms in an osteoarthritis mouse model, as shown through the functional tests (n = 10; *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001), modulation of the expression level of the pro-inflammatory and anti-inflammatory genes, and improved osteochondral regeneration as demonstrated by tissue sections. ConclusionOur study identified the FGF-2-derived peptide FP2 as a promising candidate peptide to improve the therapeutic potential of hWJ-MSCs, especially in bone and cartilage regeneration.

Targeting FGFR Pathways in Gastrointestinal Cancers: New Frontiers of Treatment.

In carcinogenesis of the gastrointestinal (GI) tract, the deregulation of fibroblast growth factor receptor (FGFR) signaling plays a critical role. The aberrant activity of this pathway is described in approximately 10% of gastric cancers and its frequency increases in intrahepatic cholangiocarcinomas (iCCAs), with an estimated frequency of 10-16%. Several selective FGFR inhibitors have been developed in the last few years with promising results. For example, targeting the FGFR pathway is now a fundamental part of clinical practice when treating iCCA and many clinical trials are ongoing to test the safety and efficacy of anti-FGFR agents in gastric, colon and pancreatic cancer, with variable results. However, the response rates of anti-FGFR drugs are modest and resistances emerge rapidly, limiting their efficacy and causing disease progression. In this review, we aim to explore the landscape of anti-FGFR inhibitors in relation to GI cancer, with particular focus on selective FGFR inhibitors and drug combinations that may lead to overcoming resistance mechanisms and drug-induced toxicities.

Prenatal FGFR2 Signaling via PI3K/AKT Specifies the PDGFRA+ Myofibroblast.

It is well known that FGFR2 (fibroblast growth factor receptor 2) signaling is critical for proper lung development. Recent studies demonstrate that epithelial FGFR2 signaling during the saccular phase of lung development (sacculation) regulates alveolar type 1 (AT1) and AT2 cell differentiation. During sacculation, PDGFRA (platelet-derived growth factor receptor-α)-positive lung fibroblasts exist as three functional subtypes: contractile myofibroblasts, extracellular matrix-producing matrix fibroblasts, and lipofibroblasts. All three subtypes are required during alveolarization to establish a niche that supports AT2 epithelial cell self-renewal and AT1 epithelial cell differentiation. FGFR2 signaling directs myofibroblast differentiation in PDGFRA+ fibroblasts during alveolar reseptation after pneumonectomy. However, it remains unknown if FGFR2 signaling regulates PDGFRA+ myo-, matrix, or lipofibroblast differentiation during sacculation. In this study, FGFR2 signaling was inhibited by temporal expression of a secreted dominant-negative FGFR2b (dnFGFR2) by AT2 cells from embryonic day (E) 16.5 to E18.5. Fibroblast and epithelial differentiation were analyzed at E18.5 and postnatal days 7 and 21. At all time points, the number of myofibroblasts was reduced and the number of lipo-/matrix fibroblasts was increased. AT2 cells are increased and AT1 cells are reduced postnatally, but not at E18.5. Similarly, in organoids made with PDGFRA+ fibroblasts from dnFGFR2 lungs, increased AT2 cells and reduced AT1 cells were observed. In vitro treatment of primary wild-type E16.5 adherent saccular lung fibroblasts with recombinant dnFGFR2b/c resulted in reduced myofibroblast contraction. Treatment with the PI3K/AKT activator 740 Y-P rescued the lack of myofibroblast differentiation caused by dnFGFR2b/2c. Moreover, treatment with the PI3K/AKT activator 740 Y-P rescued myofibroblast differentiation in E18.5 fibroblasts isolated from dnFGFR2 lungs.

The impact of poor metabolic health on aggressive breast cancer: adipose tissue and tumor metabolism.

Obesity and type 2 diabetes are chronic metabolic diseases that impact tens to hundreds of millions of adults, especially in developed countries. Each condition is associated with an elevated risk of breast cancer and with a poor prognosis after treatment. The mechanisms connecting poor metabolic health to breast cancer are numerous and include hyperinsulinemia, inflammation, excess nutrient availability, and adipose tissue dysfunction. Here, we focus on adipose tissue, highlighting important roles for both adipocytes and fibroblasts in breast cancer progression. One potentially important mediator of adipose tissue effects on breast cancer is the fibroblast growth factor receptor (FGFR) signaling network. Among the many roles of FGFR signaling, we postulate that key mechanisms driving aggressive breast cancer include epithelial-to-mesenchymal transition and cellular metabolic reprogramming. We also pose existing questions that may help better understand breast cancer biology in people with obesity, type 2 diabetes, and poor metabolic health.

Effect of Juanbi Qianggu Formula on biological behaviors of fibroblast-like synoviocytes in rheumatoid arthritis by regulating FGFR1 signaling pathway based on network pharmacology and cell function experiments

This study aimed to explore the molecular mechanism of Juanbi Qianggu Formula(JBQGF), an empirical formula formulated by the prestigious doctor in traditional Chinese medicine, in the treatment of rheumatoid arthritis based on network pharmacology and cell function experiments. The main active components and targets of JBQGF were obtained through Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP) and Encyclopedia of Traditional Chinese Medicine(ETCM), and the core targets underwent functional enrichment analysis and signaling pathway analysis. Cytoscape 3.6.0 was used to construct a visualized &quot;active component-target-signaling pathway&quot; network of JBQGF. After screening, nine potential pathways of JBQGF were obtained, mainly including G protein-coupled receptor signaling pathway and tyrosine kinase receptor signaling pathway. As previously indicated, the fibroblast growth factor receptor 1(FGFR1) signaling pathway was highly activated in active fibroblast-like synoviocytes(FLS) in rheumatoid arthritis, and cell and animal experiments demonstrated that inhibition of the FGFR1 signaling pathway could significantly reduce joint inflammation and joint destruction in collagen-induced arthritis(CIA) rats. In terms of the tyrosine kinase receptor signal transduction pathway, the analysis of its target genes revealed that FGFR1 might be a potential target of JBQGF for rheumatoid arthritis treatment. The biological effect of JBQGF by inhibiting FGFR1 phosphorylation was preliminarily verified by Western blot, Transwell invasion assay, and pannus erosion assay, thereby inhibiting matrix metalloproteinase 2(MMP2) and receptor activator of nuclear factor-κB ligand(RANKL) and suppressing the invasion of fibroblasts in rheumatoid arthritis and erosive effect of pannus bone. This study provides ideas for searching potential targets of rheumatoid arthritis treatment and TCM drugs through network pharmacology.