Overexpression Of Fibroblast Growth Factor Receptor Research Articles

Fibroblast growth factor receptor four inhibitor FGF401 improves the efficacy of trastuzumab in FGFR4-overexpressing breast cancer cells.

Breast cancer is the most common cancer among women. Among them, human epidermal growth factor receptor-positive (HER2+) breast cancer is more malignant. Fortunately, many anti-HER2 drugs are currently used in clinical treatments to increase patient survival. However, some HER2+ patients (~15%) still develop drug resistance after receiving trastuzumab treatment, leading to treatment failure. Using CCLE and METABRIC database analyses, we found that fibroblast growth factor receptor 4 (FGFR4) mRNA was highly detected in tumors from HER2+ breast cancer patients (p < .001) and was associated with poorer survival in breast cancer patients. Through retrospective immunohistochemical staining analysis, we detected higher expression of FGFR4 protein in breast cancer tissues collected from patients who were resistant to trastuzumab therapy compared with breast cancer patients who responded to treatment. An FGFR4 inhibitor (FGF401) effectively inhibits tumor growth in trastuzumab-insensitive patient-derived xenograft (PDX) tumor-bearing mice. For molecular mechanism studies, we demonstrated that HER2/FGFR4 protein complexes were detected on the cell membrane of the tumor tissues in these trastuzumab-insensitive PDX tumor tissues. After trastuzumab treatment in these drug-resistant breast cancer cells, FGFR4 translocates and enters the nucleus. However, trastuzumab-induced nuclear translocation of FGFR4/HER2-intracellular domain protein complex in trastuzumab-resistant cancer cells is blocked by FGF401 treatment. We believe that FGFR4 overexpression and complex formation with HER2 can serve as molecular markers to assist clinicians in identifying trastuzumab-resistant tumors. Our results suggest that FGF401 combined with trastuzumab as adjuvant therapy for patients with trastuzumab-resistant breast cancer may be a potential new treatment strategy.

DNA methylation-mediated FGFR1 silencing enhances NF-κB signaling: implications for asthma pathogenesis.

Fibroblast growth factor receptor 1 (FGFR1) is known to play a crucial role in the pathogenesis of asthma, although the precise mechanism remains unclear. This study aims to investigate how DNA methylation-mediated silencing of FGFR1 contributes to the enhancement of NF-κB signaling, thereby influencing the progression of asthma. RT-qPCR was utilized to assess FGFR1 mRNA levels in the serum of asthma patients and BEAS-2B, HBEpiC, and PCS-301-011 cells. CCK8 assays were conducted to evaluate the impact of FGFR1 overexpression on the proliferation of BEAS-2B, PCS-301-011, and HBEpiC cells. Dual-luciferase and DNA methylation inhibition assays were performed to elucidate the underlying mechanism of FGFR1 gene in asthma. The MassARRAY technique was employed to measure the methylation levels of the FGFR1 DNA. Elevated FGFR1 mRNA levels were observed in the serum of asthma patients compared to healthy controls. Overexpression of FGFR1 in BEAS-2B cells significantly enhanced cell proliferation and stimulated NF-ĸB transcriptional activity in HERK-293T cells. Furthermore, treatment with 5-Aza-CdR, a DNA demethylating agent, markedly increased the expression of FGFR1 mRNA in BEAS-2B, PCS-301-011, and HBEpiC cells. Luciferase activity analysis confirmed heightened NF-ĸB transcriptional activity in FGFR1-overexpressing BEAS-2B cells and BEAS-2B cells treated with 5-Aza-CdR. Additionally, a decrease in methylation levels in the FGFR1 DNA promoter was detected in the serum of asthma patients using the MassARRAY technique. Our findings reveal a potential mechanism involving FGFR1 in the progression of asthma. DNA methylation of FGFR1 inactivates the NF-ĸB signaling pathway, suggesting a promising avenue for developing effective therapeutic strategies for asthma.

Identification of mechanism of the oncogenic role of FGFR1 in papillary thyroid carcinoma.

Papillary thyroid carcinoma (PTC) is the most prevalent malignancy of the thyroid. Fibroblast growth factor receptor 1 (FGFR1) is highly expressed in PTC and works as an oncogenic protein in this disease. In this report, we wanted to uncover a new mechanism that drives overexpression of FGFR1 in PTC. Analysis of FGFR1 expression in clinical specimens and PTC cells revealed that FGFR1 expression was enhanced in PTC. Using siRNA/shRNA silencing experiments, we found that FGFR1 downregulation impeded PTC cell growth, invasion, and migration and promoted apoptosis in vitro, as well as suppressed tumor growth in vivo. Bioinformatic analyses predicted the potential USP7-FGFR1 interplay and the potential binding between YY1 and the FGFR1 promoter. The mechanism study found that USP7 stabilized FGFR1 protein via deubiquitination, and YY1 could promote the transcription of FGFR1. Our rescue experiments showed that FGFR1 re-expression had a counteracting effect on USP7 downregulation-imposed in vitro alterations of cell functions and in vivo suppression of xenograft growth. In conclusion, our study identifies the deubiquitinating enzyme USP7 and the oncogenic transcription factor YY1 as potent inducers of FGFR1 overexpression. Designing inhibitors targeting FGFR1 or its upstream inducers USP7 and YY1 may be foreseen as a promising strategy to control PTC development.

Abstract 638: FGFR4 mediates nuclear accumulation of NRF2 by binding to P62 in gastric cancer

Abstract Background: Helicobacter pylori (H. pylori) is the major cause of gastric cancer. Fibroblast growth factor receptor 4 (FGFR4) is a member of the highly conserved tyrosine kinase family known to be activated in cancer. Nuclear Factor Erythroid 2-Related Factor 2 (NRF2), a transcription factor, is essential for the antioxidant response and exhibits cytoprotective properties against cellular stress and oxidative damage. This study investigates the novel functions of FGFR4 and its role in regulating the antioxidant response in gastric tumorigenesis. Methods: We used public datasets, gastric tissues from mice and human, and gastric cancer cell lines. In vitro and in vivo H. pylori infections were performed. Western blot, RT-qPCR, Immunofluorescence, flow cytometry, Immunohistochemistry, Immunoprecipitation, Proximity ligation assay and Luciferase reporter assays were performed. Results: The analysis of a public dataset revealed that overexpression of FGFR4 is associated with an oxidative stress signature and poor survival. Gene set enrichment analysis (GSEA) showed that tissue samples with high FGFR4 levels had an enrichment of NRF2 signature genes. In vitro cell models infected with H. pylori showed an increase in reactive oxygen species (ROS). Knockdown of FGFR4 resulted in significant reductions in NRF2 protein and transcriptional activity, leading to increased ROS levels and DNA damage. Immunofluorescence analysis using various models confirmed that FGFR4 knockdown reversed the accumulation of NRF2 in the nucleus. Dysplastic and neoplastic gastric lesions in the TFF1-KO mouse model exhibited high levels of both FGFR4 and NRF2. Pharmacologic inhibition or knockdown of FGFR4 significantly decreased NRF2 levels, as well as the size and number of gastric cancer spheroids. Mechanistically, elevated levels of P62 protein were associated with FGFR4 expression. Binding between FGFR4 and P62 proteins, which competes with NRF2-KEAP1 interaction, was detected using immunoprecipitation and proximity ligation assay. Immunohistochemistry analysis on a tissue microarray showed increased FGFR4 immunostaining in HGD/Cancer samples compared to adjacent normal samples, and this increase correlated with an increase in NRF2 and P62 levels. Conclusion: These findings revealed that FGFR4 has a distinct functional role in promoting gastric carcinogenesis. FGFR4 binds to P62 to inhibit the interaction between NRF2 and KEAP1, allowing NRF2 to avoid degradation facilitating its translocation and accumulation in the nucleus. The use of FGFR4 inhibitors is a viable treatment option that warrants further research in patients with gastric cancer. Citation Format: Nadeem S. Bhat, Mohammed Soutto, Xing Zhang, Zheng Chen, Shoumin Zhu, Selma Maacha, Melanie Genoula, Dunfa Peng, Heng Lu, Oliver G McDonald, Xi Steven Chen, Longlong Cao, Zekuan Xu, Wael El-Rifai. FGFR4 mediates nuclear accumulation of NRF2 by binding to P62 in gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 638.

FGFR2 and miR-889-3p expression in oral cancer is associated with cervical lymph node metastasis.

Fibroblast growth factor receptor-2 (FGFR2) and miR-889-3p expression in oral squamous cell carcinoma (OSCC) tumours were compared to normal controls. We then examined the relationship between miR-889-3p, FGFR2 expression and patient clinicopathological features. The interaction of FGFR2 and miR-889-3p was investigated using bioinformatics. Then, OSCC tumour biopsies and normal gingiva were collected and processed for expression analysis of FGFR2-specific mRNA and miR-889-3p using real-time PCR. Immunohistochemistry evaluated the expression of the FGFR2 protein. The protein and mRNA expression levels of FGFR2 were significantly greater in tumours when contrasted with controls. Expression of miR-889-3p was significantly lower in OSCC compared to normal tissues. The FGFR2 and miR-889-3p expressions were inversely related (-0.86 and -0.73, respectively) in both cases and controls. Changes in miR-889-3p and FGFR2 expression in tumour tissues were associated with lymph node metastasis (LNM), with ~0.57 and ~3.0 folds of change in positive-LNM patients, respectively. Decreased expression of miR-889-3p in OSCC tumours suggests that miR-889-3p functions as a tumour suppressor gene. Overexpression of FGFR2 further proves the role of miR-889-3p in the regulation of the FGFR2 pathway. This was further confirmed by showing differences in miR-889-3p expression in positive and negative LNM cases.

CircNINL facilitates aerobic glycolysis, proliferation, invasion, and migration in lung cancer by sponging miR-3918 to mediate FGFR1 expression

Previously characterized as an oncogenic player in breast cancer, the function of circular RNA NINL (circNINL) in lung cancer (LC) remained elusive. This study aimed to delineate the biological role of circNINL in LC and to unveil its potential molecular mechanisms. We discovered elevated expression levels of circNINL and Fibroblast Growth Factor Receptor 1 (FGFR1) concomitant with diminished expression of microRNA-3918 (miR-3918) in LC specimens. Knockdown of circNINL led to a marked decrease in cell proliferation, migration, invasion, and aerobic glycolysis, alongside an upsurge in apoptosis in LC cells. Either downregulation of miR-3918 or overexpression of FGFR1 mitigated the suppressive impact of circNINL knockdown on LC pathogenesis. Mechanistic studies validated that circNINL served as a competitive endogenous RNA for miR-3918, thus influencing FGFR1 expression. Further, in vivo experiments using nude mouse xenograft models underscored that silencing circNINL substantially curtailed tumor growth in LC. Collectively, these findings illuminate that circNINL exacerbates LC malignancy via the miR-3918/FGFR1 axis, a process integrally linked with the activation of aerobic glycolysis.Graphical

Engineering an fgfr4 knockout zebrafish to study its role in development and disease.

Fibroblast growth factor receptor 4 (FGFR4) has a role in many biological processes, including lipid metabolism, tissue repair, and vertebrate development. In recent years, FGFR4 overexpression and activating mutations have been associated with numerous adult and pediatric cancers. As such, FGFR4 presents an opportunity for therapeutic targeting which is being pursued in clinical trials. To understand the role of FGFR4 signaling in disease and development, we generated and characterized three alleles of fgfr4 knockout zebrafish strains using CRISPR/Cas9. To generate fgfr4 knockout crispants, we injected single-cell wildtype zebrafish embryos with fgfr4 targeting guide RNA and Cas9 proteins, identified adult founders, and outcrossed to wildtype zebrafish to create an F1 generation. The generated mutations introduce a stop codon within the second Ig-like domain of Fgfr4, resulting in a truncated 215, 223, or 228 amino acid Fgfr4 protein compared to 922 amino acids in the full-length protein. All mutant strains exhibited significantly decreased fgfr4 mRNA expression during development, providing evidence for successful knockout of fgfr4 in mutant zebrafish. We found that, consistent with other Fgfr4 knockout animal models, the fgfr4 mutant fish developed normally; however, homozygous fgfr4 mutant zebrafish were significantly smaller than wildtype fish at three months post fertilization. These fgfr4 knockout zebrafish lines are a valuable tool to study the role of FGFR4 in vertebrate development and its viability as a potential therapeutic target in pediatric and adult cancers, as well as other diseases.

A novel intronic circular RNA circFGFR1int2 up-regulates FGFR1 by recruiting transcriptional activators P65/FUS and suppressing miR-4687-5p to promote prostate cancer progression

Fibroblast growth factor receptor 1 (FGFR1) is a core component of the FGFs/FGFR pathway that activates multiple signalling pathways, including ERK1/2, PI3K/AKT, PLCγ, and NF-κB. Aberrant expression of FGFR1 due to gene amplification, chromosome rearrangement, point mutation, and epigenetic deregulations, have been reported in various cancers. FGFR1 overexpression has also been reported in prostate cancer (PCa), but the underlining mechanisms are not clear. Here we report a novel circular RNA, circFGFR1int2, derived from intron 2 of FGFR1 gene, which is overexpressed in PCa and associated with tumor progression. Importantly, we show that circFGFR1int2 facilitates FGFR1 transcription by recruiting transcription activators P65/FUS and by interacting with FGFR1 promoter. Moreover, we show that circFGFR1int2 suppresses post-transcriptional inhibitory effects of miR-4687-5p on FGFR1 mRNA. These mechanisms synergistically promote PCa cell growth, migration, and invasion. Overexpression of circFGFR1int2 is significantly correlated with higher tumor grade, Gleason score, and PSA level, and is a significant unfavorable prognosticator for CRPC-free survival (CFS) (RR = 3.277, 95% confidence interval: 1.192–9.009; P = 0.021). These findings unravelled novel mechanisms controlling FGFR1 gene expression by intronic circRNA and its potential clinicopathological utility as a diagnostic or therapeutic target.Graphic

NF-κB downstream miR-1262 disturbs colon cancer cell malignant behaviors by targeting FGFR1.

Despite substantial advancements in screening, surgery, and chemotherapy, colorectal cancer remains the second most lethal form of the disease. Nuclear factor kappa B (NF-κB) signaling is a critical driver facilitating the malignant transformation of chronic inflammatory bowel diseases. In this study, deregulated miRNAs that could play a role in colon cancer are analyzed and investigated for specific functions in vitro using cancer cells and in vivo using a subcutaneous xenograft model. miRNA downstream targets are analyzed, and predicted binding and regulation are verified. miR-1262, an antitumor miRNA, is downregulated in colon cancer tissue samples and cell lines. miR-1262 overexpression suppresses colon cancer malignant behaviors in vitro and tumor development and metastasis in a subcutaneous xenograft model and a lung metastasis mouse model in vivo. miR-1262 directly targets fibroblast growth factor receptor 1 (FGFR1) and inhibits FGFR1 expression. FGFR1 overexpression shows oncogenic functions through the regulation of cancer cell proliferation, invasion, and migration; when cotransfected, lv-FGFR1 partially attenuates the antitumor effects of agomir-1262. NF-κB binds to the miR-1262 promoter region and inhibits transcription activity. The NF-κB inhibitor CAPE exerts antitumor effects; miR-1262 inhibition partially reverses CAPE effects on colon cancer cells. Conclusively, miR-1262 serves as an antitumor miRNA in colon cancer by targeting FGFR1. The NF-κB/miR-1262/FGFR1 axis modulates colon cancer cell phenotypes, including proliferation, invasion, and migration.

P53, CK20, and FGFR3 Overexpression is Associated with the Characteristics of Urothelial Cell Carcinoma of the Bladder

The aim of this study was to investigate the association between the overexpression of tumor protein (P53), cytokeratin 20 (CK20), fibroblast growth factor receptor 3 (FGFR3), biomarkers and the grading, prognosis, heterogeneity, and relapse tendency of urothelial cell carcinomas (UCCs) of the bladder. A cross-sectional study was conducted using 413 samples of Iranian patients diagnosed with UCC of the bladder. The tissue microarray technique was used to evaluate the patterns of tumor tissue. Two pathologists scored tissue staining using a semi-quantitative scoring system. The results showed that P53 was a predictor of a high-grade pattern (the area under the curve (AUC)=0.620) with a best cut-off value of 95.0 using the receiver operating characteristic (ROC) curve. CK20 was another predictor of a high-grade pattern (AUC=0.745) with a best cut-off value of 15. However, the overexpression of both biomarkers was not associated with a heterogeneous pattern and could not predict tumor-associated death or relapse. The heterogeneous (odds ratio (OR)=4.535, p-value=0.001) and non-papillary (OR= 6.363, p-value= 0.001) patterns were effective predictors of tumor recurrence among all baseline variables, including patient and tumor characteristics. FGFR3 was positive in all specimens and was not a valuable biomarker for differentiating patterns. None of the variables predicted tumor prognosis. The study findings indicate that the intensity and percentage of cell staining for P53 and CK20 in the UCC of the bladder can aid in differentiating the grading patterns. The tendency of tumor relapse can be predicted by demonstrating heterogeneous and non-papillary patterns.

FGFR3 and FGFR4 overexpression in juvenile nasopharyngeal angiofibroma: impact of smoking history and implications for personalized management.

Lifestyle factors, including smoking, have been linked to neoplastic diseases, and reports suggest an association between smoking and overexpression of FGFR (fibroblast growth factor receptor) in certain neoplasms. This study aims to assess the expression of FGFR3 and FGFR4 genes in patients with and without a history of smoking.A total of 118 participants were recruited, including 83 Juvenile Nasopharyngeal Angiofibroma (JNA) patients and 35 healthy participants, the JNA patients were further stratified as smokers and nonsmokers. Total RNA was extracted from the blood & saliva sample by using TRIzol reagent, and quantified using a Nanodrop, and then subjected to gene expression analysis of FGFR3/4 using RT-PCR. Immunohistochemistry analysis was employed using fresh biopsies of JNA to validate the findings. All experiments were performed in triplicates and analysed using the Chi-Square test (P < 0.05). Smokers exhibited significantly lower total RNA concentrations across all sample types (P < 0.001). The study revealed significant upregulation of both FGFR3/4 genes in JNA patients (P < 0.05). Moreover, FGFR3 expression was significantly higher among smokers 66% (95% CI: 53-79%) compared to non-smokers 22% (95% CI: 18-26%). Immunohistochemistry analysis demonstrated moderate to strong staining intensity for FGFR3 among smokers. The study highlights the overexpression of FGFR3/4 genes in JNA patients, with a stronger association observed among smokers. Furthermore, medical reports indicated higher rates of recurrence and bleeding intensity among smokers. These findings emphasize the potential role of FGFR3 as a key molecular factor in JNA, particularly in the context of smoking.

Circ_0008234 regulates the biological process of gallbladder carcinoma by targeting the miR-204-5p/FGFR2 axis.

Gallbladder carcinoma (GBC) is a common cancer disease with high mortality. Circular RNA_0008234 (circ_0008234) has been shown to play a key role in many tumors, including GBC. However, the function between circ_0008234 and microRNA-204-5p (miR-204-5p) in the progression of GBC has not been clarified. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expressions of circ_0008234, miR-204-5p and fibroblast growth factor receptor-2 (FGFR2) in GBC cells and tissues. Western blot was used to detect the expression of relative proteins. Cell proliferation, apoptosis, invasion and migration were detected by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, thymidine analog 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry, transwell assay and wound healing assay. Mechanically, the interaction of miR-204-5p with circ_0008234/FGFR2 was notarized by dual-luciferase reporter assay. A xenotransplantation model was established to study the role of circ_0008234 in vivo. Circ_0008234 and FGFR2 were highly expressed in GBC tissues and cells. Silencing circ_0008234 down-regulated cell proliferation, migration and invasion of NOZ and SGC-996 cells, while miR-204-5p inhibitors reversed these effects. In addition, overexpression of FGFR2 restored the cell malignant behavior of GBC cells inhibited by miR-204-5p mimic. Animal experiments confirmed the anti-tumor effect of silenced circ_0008234 in vivo. Circ_0008234 mediated GBC via the miR-204-5p/FGFR2 axis, providing a novel targeted therapy for gallbladder carcinoma.

Targeted therapy of advanced parathyroid carcinoma guided by genomic and transcriptomic profiling.

Parathyroid carcinoma (PC) is an ultra-rare malignancy with a high risk of recurrence after surgery. Tumour-directed systemic treatments for PC are not established. We used whole-genome and RNA sequencing in four patients with advanced PC to identify molecular alterations that could guide clinical management. In two cases, the genomic and transcriptomic profiles provided targets for experimental therapies that resulted in biochemical response and prolonged disease stabilization: (a) immune checkpoint inhibition with pembrolizumab based on high tumour mutational burden and a single-base substitution signature associated with APOBEC (apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like) overactivation; (b) multi-receptor tyrosine kinase inhibition with lenvatinib due to overexpression of FGFR1 (Fibroblast Growth Factor Receptor 1) and RET (Ret Proto-Oncogene) and, (c)later in the course of the disease, PARP (Poly(ADP-Ribose) Polymerase) inhibition with olaparib prompted by signs of defective homologous recombination DNA repair. In addition, our data provided new insights into the molecular landscape of PC with respect to the genome-wide footprints of specific mutational processes and pathogenic germline alterations. These data underscore the potential of comprehensive molecular analyses to improve care for patients with ultra-rare cancers based on insight into disease biology.

Inhibition of FGFR2 Signaling by Cynaroside Attenuates Liver Fibrosis.

Liver fibrosis represents a significant health hazard with a high morbidity rate and an increased risk of liver cancer. Targeting overactivated Fibroblast growth factor receptor 2 (FGFR2) is a promising strategy to counteract collagen accumulation during liver fibrosis. However, there is a shortage of drugs to specifically block the activation of FGFR2 in liver fibrosis patients. Data mining, cell validation, and animal studies showed a positive correlation between FGFR2 overexpression and liver fibrosis development. Novel FGFR2 inhibitors were screened using a microarray-based high-throughput binding analysis. The effectiveness of each candidate was validated through simulated docking, binding affinity verification, single-point mutation validation, and in vitro kinase inhibition measurements to demonstrate the ability of each inhibitor to block the catalytic pocket and reverse FGFR2 overactivation. A specific FGFR2 inhibitor, cynaroside (CYN, also known as luteoloside), was screened based on the finding that FGFR2 promotes hepatic stellate cell (HSC) activation and collagen secretion in hepatocytes. The results from cellular assays showed that CYN can inhibit FGFR2 hyperactivation resulting from its overexpression and excessive basic fibroblast growth factor (bFGF), reducing HSC activation and collagen secretion in hepatocytes. Animal experiments on a carbon tetrachloride (CCl4) mouse model and a nonalcoholic steatohepatitis mouse model indicate that CYN treatment reduces liver fibrosis during fibrosis formation. These findings suggest that CYN prevents liver fibrosis formation at the cell level and in mouse models.

FGFR2 upregulates PAI-1 via JAK2/STAT3 signaling to induce M2 polarization of macrophages in colorectal cancer

Fibroblast growth factor receptor 2 (FGFR2) is frequently activated by overexpression or mutation, and an abnormal fibroblast growth factor (FGF)/FGFR signaling pathway is associated with the occurrence, development, and poor prognosis of colorectal cancer (CRC). Our preliminary analysis found that plasminogen activator inhibitor-1 (PAI-1) expression may be related to FGF/FGFR signaling, however, their role in the tumor immune microenvironment remains unclear. In this study, we observed markedly higher PAI-1 expression in CRC patients with poor survival rates. PAI-1 is regulated by FGF/FGFR2 in colon cancer cells and is involved in M2 macrophage polarization. Mechanistically, inhibiting the JAK2/STAT3 signaling pathway could cause PAI-1 downregulation. Furthermore, the activation of phosphorylated STAT3 upregulated PAI-1. In vivo, FGFR2 overexpression in tumor-bearing mouse models suggested that a PAI-1 inhibitor could rescue FGFR2/PAI-1 axis-induced M2 macrophage polarization, which leads to effective immune activity and tumor suppression. Moreover, the combination of a PAI-1 inhibitor and anti-PD-1 therapy exhibited superior antitumor activity in mice. These findings offer novel insights into the molecular mechanisms underlying tumor deterioration and provide potential therapeutic targets for CRC treatment.

FGFR3 Mutational Activation Can Induce Luminal-like Papillary Bladder Tumor Formation and Favors a Male Sex Bias

BackgroundBladder cancer (BCa) is more common in men and presents differences in molecular subtypes based on sex. Fibroblast growth factor receptor 3 (FGFR3) mutations are enriched in the luminal papillary muscle-invasive BCa (MIBC) and non-MIBC subtypes. ObjectiveTo determine whether FGFR3 mutations initiate BCa and impact BCa male sex bias. Design, setting, and participantsWe developed a transgenic mouse model expressing the most frequent FGFR3 mutation, FGFR3-S249C, in urothelial cells. Bladder tumorigenesis was monitored in transgenic mice, with and without carcinogen exposure. Mouse and human BCa transcriptomic data were compared. InterventionMutant FGFR3 overexpression in mouse urothelium and siRNA knockdown in cell lines, and N-butyl-N(4-hydroxybutyl)-nitrosamine (BBN) exposure. Outcome measurements and statistical analysisImpact of transgene dosage on tumor frequency, synergy with BBN treatment, and FGFR3 pathway activation were analyzed. The sex-specific incidence of FGFR3-mutated tumors was evaluated in mice and humans. FGFR3 expression in FGFR3-S249C mouse urothelium and in various human epithelia was measured. Mutant FGFR3 regulation of androgen (AR) and estrogen (ESR1) receptor activity was evaluated, through target gene expression (regulon) and reporter assays. Results and limitationsFGFR3-S249C expression in mice induced low-grade papillary BCa resembling human luminal counterpart at histological, genomic, and transcriptomic levels, and promoted BBN-induced basal BCa formation. Mutant FGFR3 expression levels impacted tumor incidence in mice, and mutant FGFR3–driven human tumors were restricted to epithelia presenting high normal FGFR3 expression levels. BCa male sex bias, also found in our model, was even higher in human FGFR3-mutated tumors compared with wild-type tumors and was associated with higher AR and lower ESR1 regulon activity. Mutant FGFR3 expression inhibited both ESR1 and AR activity in mouse tumors and human cell lines, demonstrating causation only between FGFR3 activation and low ESR1 activity in tumors. ConclusionsMutant FGFR3 initiates luminal papillary BCa formation and favors BCa male sex bias, potentially through FGFR3-dependent ESR1 downregulation. Patients with premalignant lesions or early-stage BCa could thus potentially benefit from FGFR3 targeting. FGFR3 expression level in epithelia could account for FGFR3-driven carcinoma tissue specificity. Patient summaryBy developing a transgenic mouse model, we showed that gain-of-function mutations of FGFR3 receptor, among the most frequent genetic alterations in bladder cancer (BCa), initiate BCa formation. Our results could support noninvasive detection of FGFR3 mutations and FGFR3 targeting in early-stage bladder lesions.

The novel FGFR inhibitor F1-7 induces DNA damage and cell death in colon cells.

Fibroblast growth factor receptor (FGFR) signaling influenced tumour occurrence and development. Overexpression of FGFR had been observed in many types of cancers, including colon cancer. FGFR inhibitor is considered to be effective in treating colon cancer patients. First, the kinase inhibition rate was determined. MTT, western blotting, colony formation, EdU and comet assays were performed to evaluate the anti-tumour effects of F1-7 in vitro. RNA-seq and bioinformatics analysis were used for further verification. Additionally, a xenograft model was generated to investigate the anti-tumour effect of F1-7. F1-7 can inhibit the proliferation of colon cancer cells in vitro. It could significantly inhibit FGFR phosphorylation and its downstream signaling pathway. Whole-genome RNA-seq analysis found that the changed genes were not only functionally focused on MAPK signaling pathway but also related to cell apoptosis and ferroptosis. Experimental evidence demonstrated that F1-7 can directly increase the level of cellular DNA damage. The occurrence of DNA damage led to cell cycle arrest and inhibition of cell metastasis and cell apoptosis. Mouse model experiments also confirmed that F1-7 could inhibit tumour growth by inhibiting the FGFR pathway. F1-7 exhibits anti-tumour activity by inhibiting the FGFR pathway. It could be a novel therapeutic agent for targeting colon cancer cells.

Intra-tumoral FGFR2 Expression Predicts Prognosis and Chemotherapy Response in Advanced HER2-positive Gastric Cancer Patients.

This study aimed to evaluate the relationship between clinical outcomes and intra-tumoral fibroblast growth factor receptor 2 (FGFR2) expression in human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC) patients who had undergone HER2-targeted chemotherapy. A retrospective analysis was performed in 22 patients with HER2-positive GC, who had undergone systemic chemotherapy. We performed immunohistochemistry staining of FGFR2 expression using surgically resected specimens or biopsied samples and evaluated clinicopathological characteristic and overall survival (OS) in the FGFR2-negative and -positive GC groups. A total of 8 and 14 patients were placed in the FGFR2-negative and -positive group, respectively. The median OS rates were 56.2 and 16.0 months in the FGFR2-negative and -positive groups, respectively. The FGFR2-negative group had a significantly better prognosis after HER2-targeted chemotherapy [p=0.027 (log-rank test)]. The univariate analysis revealed that performing gastrectomy, response to combination chemotherapy with trastuzumab, and FGFR2 positivity were significantly correlated with OS. In a multivariate analysis, the response to combination chemotherapy with trastuzumab (p=0.008) was significantly correlated with OS. In addition, the proportions of patients who showed CR or PR in response to chemotherapy were 87.5 and 42.9% in the FGFR2-negative and -positive groups, respectively (p=0.031). HER2-positive GC patients, without overexpression of FGFR2, exhibited an improved prognosis and response rate to trastuzumab combination chemotherapy. Assessment of intra-tumoral FGFR2 expression could be helpful in predicting the prognosis and response to trastuzumab in HER2-positive GC patients.

Knockdown of lncRNA TUG1 alleviates diabetic retinal vascular dysfunction through regulating miR-524-5p/FGFR2

ABSTRACT Long noncoding RNAs (LncRNAs) have been shown to play critical roles in the development of diabetic retinopathy (DR), which is often regarded as the most frequent cause of visual loss in the world. This study investigated the effect and mechanism of lncRNA taurine-upregulated gene 1 (TUG1) in DR. Quantitative real-time polymerase chain reaction (qRT-PCR) revealed that TUG1 was upregulated in streptozotocin (STZ)-induced rat model of DR and human retinal microvascular endothelial cells (hRMECs) incubated with high glucose (HG). TUG1 suppression decreased the proliferation, migration, and angiogenesis of HG-induced hRMECs. TUG1 sponges miR-524-5p, which is downregulated in hyperglycemia. Additionally, the fibroblast growth factor receptor 2 (FGFR2) was verified as a miR-524-5p target gene and was overexpressed in HG-treated hRMECs. More notably, overexpression of FGFR2 has been shown to significantly reduce the impact of miR-524-5p overexpression. Additionally, TUG1 silencing ameliorates diabetes mellitus-induced retinal vascular impairment in vivo. Taken together, suppressing TUG1 impairs vascular function in diabetic retinas via controlling miR-524-5p and FGFR2, suggesting a possible therapy method for DR.

FGFR2 overexpression and compromised survival in diffuse-type gastric cancer in a large central European cohort.

The significance of fibroblast growth factor receptor 2 (FGFR2) in gastric cancer (GC) has been studied predominantly in Asian patient cohorts. Data on White patients are scarce. Here, we aimed to independently validate the expression and putative tumor biological significance of FGFR2 in a large non-Asian GC cohort. Immunohistochemistry (IHC) was performed on large-area tissue sections from 493 patients with GC and evaluated using the HScore. GCs with moderate and strong FGFR2 expression were studied for Fgfr2 amplification using chromogenic in situ hybridization (CISH). Median overall survival was determined using the Kaplan-Meier method. The majority [240 (99.1%)] of FGFR2-positive GCs showed a variable combination of staining intensities with marked intratumoral heterogeneity, including weak [198 (40.2%) cases], moderate [145 (29.4%)], and strong [108 (21.9%)] staining in diverse combinations. 250 (50.9%) GCs expressed no FGFR2. Fgfr2 gene amplification was found in 40% of selected cases with high protein expression and was also heterogeneous at the cell level. FGFR2 protein expression did not correlate with patient survival in the entire cohort However, using different cutoff values, a negative correlation between FGFR2-expression and patient outcome was found for diffuse-type GC. FGFR2 expression was associated with a lower tumor grade and intestinal phenotype (p≤0.0001). FGFR2-positive diffuse-type GCs classify a small subset of patients with a poor tumor specific survival (5.29±1.3 vs. 14.67±1.9 months; p = 0.004).