Expression Of Fibroblast Growth Factor Receptor Research Articles

FGFR1-4 RNA-Based Gene Alteration and Expression Analysis in Squamous Non-Small Cell Lung Cancer.

While fibroblast growth factor receptors (FGFRs) are involved in several biological pathways and FGFR inhibitors may be useful in the treatment of squamous non-small cell lung cancer (Sq-NSCLC), FGFR aberrations are not well characterized in Sq-NSCLC. We comprehensively evaluated FGFR expression, fusions, and variants in 40 fresh-frozen primary Sq-NSCLC (stage IA3–IV) samples and tumor-adjacent normal tissues using real-time PCR and next-generation sequencing (NGS). Protein expression of FGFR1–3 and amplification of FGFR1 were also analyzed. FGFR1 and FGFR4 median gene expression was significantly (p < 0.001) decreased in tumors compared with normal tissue. Increased FGFR3 expression enhanced the recurrence risk (hazard ratio 4.72, p = 0.029), while high FGFR4 expression was associated with lymph node metastasis (p = 0.036). Enhanced FGFR1 gene expression was correlated with FGFR1 protein overexpression (r = 0.75, p = 0.0003), but not with FGFR1 amplification. NGS revealed known pathogenic FGFR2,3 variants, an FGFR3::TACC3 fusion, and a novel TACC1::FGFR1 fusion together with FGFR1,2 variants of uncertain significance not previously reported in Sq-NSCLC. These findings expand our knowledge of the Sq-NSCLC molecular background and show that combining different methods increases the rate of FGFR aberrations detection, which may improve patient selection for FGFRi treatment.

Expression and clinical significance of FGFR1 and FGFR2 in laryngeal squamous cell carcinoma.

BackgroundFibroblast growth factor receptor 1 (FGFR1) and fibroblast growth factor receptor 2 (FGFR2) may be of significance in the development of laryngeal squamous cell carcinoma (SCC) tissues. Examination of the expression results of these factors may offer new insights into treatment of the disease, such as genetic and histological targeted target therapy.MethodsWe selected tissue from 30 cases of laryngeal SCC, 23 cases of adjacent normal mucosa, and 26 cases of benign laryngeal mucosal tissues from patients who received surgery at the Otolaryngology Department of the Affiliated Hospital of Chengde Medical College between September 2020 and January 2022. The laryngeal cancers included nine cases of supraglottic, 20 glottic (vocal cord), and one case of subglottic cancer, while all benign laryngeal mucosal lesions were obtained from vocal cord polyps. The expression of FGFR1 and FGFR2 was detected in 30 laryngeal cancers, 23 adjacent normal mucosa, and 26 vocal cord polyps by immunohistochemical technology [immunohistochemistry (IHC)], and the correlation analysis of their expression in laryngeal cancer was performed. P<0.05 was represented statistically significant.ResultsThe expression of FGFR1 and FGFR2 was significantly different in laryngeal SCC and the normal tissue >0.5 cm from the tumor margin (P<0.05), and between laryngeal SCC and vocal polyps (P<0.05). There was no difference in FGFR1 and FGFR2 expression (P>0.05) between normal mucosal margins and vocal cord polyp tissue, and no correlation between FGFR1 and FGFR2 in laryngeal SCC and sex, age, smoking history, alcohol consumption history, tumor diameter, tumor lymph node metastasis, tumor differentiation degree, and Tumor-Node-Metastasis (TNM) stage (P>0.05), A moderate positive correlation between FGFR1 expression and FGFR2 expression in laryngeal SCC was seen (Rs=0.499, P<0.01).ConclusionsFGFR1 and FGFR2 may participate in the occurrence of SCC of the throat: (I) positive FGFR1 and FGFR2 expressions are not associated with gender, age, smoking history, alcohol consumption history, tumor diameter, lymph node metastasis, degree of differentiation, or TNM stage. (II) FGFR2 increases successively with higher FGFR1 expression and with a positive correlation in laryngeal SCC.

Circ_SNX27 regulates hepatocellular carcinoma development via miR-637/FGFR1 axis.

Circular RNAs (circRNAs) serve as critical regulatory factors in cancer development. Nonetheless, the potential regulatory mechanism of circRNA sorting nexin 27 (circ_SNX27) in hepatocellular carcinoma (HCC) is still unknown. The circ_SNX27, microRNA-637 (miR-637), and fibroblast growth factor receptor 1 (FGFR1) levels were quantified by quantitative real-time polymerase chain reaction and western blot analysis. Next, function experiments were conducted using in vitro assays and in vivo senograft study. The relationship between miR-637 with circ_SNX27 or FGFR1 was uncovered by dual-luciferase reporter and RNA pull-down assays. The circ_SNX27 and FGFR1 levels were up-regulated, but miR-637 content was reduced in HCC. Circ_SNX27 down-regulation inhibited HCC cell proliferation, motility, and invasion and promoted apoptosis in vitro, as well as weakened tumor growth in vivo. Circ_SNX27 served as a sponge of miR-637 to promote FGFR1 expression. MiR-637 reduction abolished the restrained effect of circ_SNX27 absence on HCC cell development. Moreover, miR-637 curbed HCC cell malignant phenotype by regulating FGFR1. Circ_SNX27 contributed to HCC development via miR-637/FGFR1 axis, offering a new idea for the treatment of HCC.

The Role of the Key Differentially Mutated Gene FGFR3 in the Immune Microenvironment of Bladder Cancer.

The tumor microenvironment (TME) has been a major focus of research in recent years as a crucial factor in the development and progression of bladder cancer. Unfortunately, the precise composition of TME, particularly the immunological and stromal components, remains unknown. In this work, we downloaded the RNA-seq expression profiles and somatic mutation data of 433 bladder cancer cases from The Cancer Genome Atlas (TCGA) and then employed a comprehensive bioinformatics approach to evaluate them. Firstly, the expression profiles were used to predict the scores and then the content of immune and stromal cells via the estimate package in R software. We then identified differentially expressed genes (DEGs) and differentially mutated genes (DMGs) according to the high-stromal score cohort and low-stromal score cohort. Finally, fibroblast growth factor receptor 3 (FGFR3) was the main differentially mutated gene in bladder carcinoma that we discovered after conducting a cross-study on DEGs and DMGs. Follow-up investigation revealed that FGFR3, whose expression correlated inversely with cancer progression stage, appeared to be a protective factor in bladder cancer. The method of Gene Set Enrichment Analysis (GSEA) was employed to, respectively, interpret the expression data of FGFR3 in high and low expression lists. We observed that the genes in the low FGFR3 expression list were strongly enriched in the biological processes associated with transplantation and cell adhesion, suggesting the possible role of FGFR3 in predicting TME metastasis status in bladder cancer. Therefore, this study is aimed at investigating whether FGFR3 is promising as a biomarker of TME remodeling to explain underlying mechanisms involved in tumorigenesis and metastasis, which may help to make decisions on treatments for bladder cancer.

Uptake of Phosphate, Calcium, and Vitamin D by the Pregnant Uterus of Sheep in Late Gestation: Regulation by Chorionic Somatomammotropin Hormone.

Minerals are required for the establishment and maintenance of pregnancy and regulation of fetal growth in mammals. Lentiviral-mediated RNA interference (RNAi) of chorionic somatomammotropin hormone (CSH) results in both an intrauterine growth restriction (IUGR) and a non-IUGR phenotype in sheep. This study determined the effects of CSH RNAi on the concentration and uptake of calcium, phosphate, and vitamin D, and the expression of candidate mRNAs known to mediate mineral signaling in caruncles (maternal component of placentome) and cotyledons (fetal component of placentome) on gestational day 132. CSH RNAi Non-IUGR pregnancies had a lower umbilical vein–umbilical artery calcium gradient (p < 0.05) and less cotyledonary calcium (p < 0.05) and phosphate (p < 0.05) compared to Control RNAi pregnancies. CSH RNAi IUGR pregnancies had less umbilical calcium uptake (p < 0.05), lower uterine arterial and venous concentrations of 25(OH)D (p < 0.05), and trends for lower umbilical 25(OH)D uptake (p = 0.059) compared to Control RNAi pregnancies. Furthermore, CSH RNAi IUGR pregnancies had decreased umbilical uptake of calcium (p < 0.05), less uterine venous 25(OH)D (vitamin D metabolite; p = 0.055), lower caruncular expression of SLC20A2 (sodium-dependent phosphate transporter; p < 0.05) mRNA, and lower cotyledonary expression of KL (klotho; p < 0.01), FGFR1 (fibroblast growth factor receptor 1; p < 0.05), FGFR2 (p < 0.05), and TRPV6 (transient receptor potential vanilloid member 6; p < 0.05) mRNAs compared to CSH RNAi Non-IUGR pregnancies. This study has provided novel insights into the regulatory role of CSH for calcium, phosphate, and vitamin D utilization in late gestation.

Expression characteristics and diagnostic value of angiogenic molecules in intravenous leiomyomatosis

Objective: This study aims to analyze the clinicopathological characteristics of patients with intravenous leiomyoma (IVL), and to explore the expression characteristics and diagnostic value of angiogenesis related molecules in IVL. Methods: The clinicopathological data of 40 patients with IVL at Women's Hospital, School of Medicine, Zhejiang University from January 2013 to April 2021 were reviewed. Log-rank test was performed to compare the difference in recurrence-free survival (RFS) rates among patients with different clinicopathological characteristics. Immunohistochemistry (IHC) staining was performed on 10 angiogenesis related molecules to analyze their expression characteristics in IVL. The sensitivity and specificity of molecules with high expression rates in the diagnosis of IVL were calculated, the receiver operating characteristic curve (ROC) was plotted and the area under ROC (AUC) was calculated to evaluate the diagnostic value. Results: Median age of the 40 patients was 47 (43, 50) years. The clinical manifestations of IVL were atypical with the diagnostic accuracy of preoperative ultrasound was 12.5% (5/40), CT and/or MRI was 26.7% (8/30), and intraoperative frozen section was 30.0% (12/40). The overall recurrence rate of IVL was 10.0% (4/40). The Log-rank test showed that the cumulative recurrence-free survival rate of IVL patients with previous cesarean section (40.9%) was lower than that of those without cesarean section (96.4%) (P<0.05); and their median RFS time was shorter than those without cesarean section (16.4 months vs 22.2 months). The overall positive rates of adrenomedullin (ADM), fibroblast growth factor receptor 1 (FGFR1), vascular endothelial growth factor receptor 3 (VEGFR3) and angiogenin receptor tyrosine kinase receptor 1 (TIE1) were 65.0% (26/40), 75.0% (30/40), 57.5% (23/40) and 50.0% (20/40), respectively. FGFR1 expression intensity and positive rate were higher in tumors with a maximum diameter greater than 5 cm than in tumors with a maximum diameter smaller than 5 cm (P<0.05). The AUC of FGFR1 combined with ADM, VEGFR3, and TIE1 was 0.876 (95%CI: 0.788-0.964, P<0.001). Conclusions: There was no typical clinical manifestation of IVL. A history of the previous cesarean section indicated a lower cumulative recurrence-free survival rate and shorter recurrence interval. It was hard to diagnose IVL by sonography, radiography, or frozen section pathology. FGFR1, ADM, VEGFR3, and TIE1 were all highly expressed in IVL, and the efficacy of the combination of the four molecules in diagnosing IVL was higher than that of imaging and classical vascular endothelial markers, which are expected to be promising molecular diagnostic markers.

FGF7/FGFR2-JunB signalling counteracts the effect of progesterone in luminal breast cancer.

We have recently demonstrated that fibroblast growth factor receptor 2 (FGFR2)‐mediated signalling alters progesterone receptor (PR) activity and response of oestrogen receptor α (ER)‐positive (ER+) breast cancer (BCa) cell lines to anti‐ER agents. Little is known about whether the crosstalk between ER and PR, shown to be modulated by the hormonal background, might also be affected by FGFR2. Here, PR‐dependent behaviour of ER+ BCa cells was studied in the presence of oestrogen (E2) and progesterone (P4) and/or FGF7. In vitro analyses showed that FGF7/FGFR2 signalling: (a) abolished the effect of P4 on E2‐promoted 3D cell growth and response to tamoxifen; (b) regulated ER and PR expression and activity; (c) increased formation of ER–PR complexes; and (d) reversed P4‐triggered deregulation of ER‐dependent genes. Analysis of clinical data demonstrated that the prognostic value of FGFR2 varied between patients with different menopausal status; that is, high expression of FGFR2 was significantly associated with longer progression‐free survival (PFS) in postmenopausal patients, whereas there was no significant association in premenopausal patients. FGFR2 was found to positively correlate with the expression of JunB proto‐oncogene, AP‐1 transcription factor subunit (JUNB), an ER‐dependent gene, only in premenopausal patients. Molecular analyses revealed that the presence of JunB was a prerequisite for FGFR2‐mediated abrogation of P4‐induced inhibition of cell growth. Our results demonstrate for the first time that the FGF7/FGFR2–JunB axis abolishes the modulatory effects of PR on ER‐associated biological functions in premenopausal ER+ BCa. This may provide foundations for a better selection of patients for FGFR‐targeting therapeutic strategies.

Fibroblast Growth Factor 7 Suppresses Fibrosis and Promotes Epithelialization during Wound Healing in Mouse Fetuses.

Adult mammalian wounds leave visible scars, whereas skin wounds in developing mouse fetuses are scarless until a certain point in development when complete regeneration occurs, including the structure of the dermis and skin appendages. Analysis of the molecular mechanisms at this transition will provide clues for achieving scarless wound healing. The fibroblast growth factor (FGF) family is a key regulator of inflammation and fibrosis during wound healing. We aimed to determine the expression and role of FGF family members in fetal wound healing. ICR mouse fetuses were surgically wounded at embryonic day 13 (E13), E15, and E17. Expression of FGF family members and FGF receptor (FGFR) in tissue samples from these fetuses was evaluated using in situ hybridization and reverse transcription-quantitative polymerase chain reaction. Fgfr1 was downregulated in E15 and E17 wounds, and its ligand Fgf7 was upregulated in E13 and downregulated in E15 and E17. Recombinant FGF7 administration in E15 wounds suppressed fibrosis and promoted epithelialization at the wound site. Therefore, the expression level of Fgf7 may correlate with scar formation in late mouse embryos, and external administration of FGF7 may represent a therapeutic option to suppress fibrosis and reduce scarring.

Abstract 5849: Activation of STAT3 is mediated by FGFR4 induction via SRC signaling after H. pylori infection

Abstract Background: Gastric cancer is considered the 5th most common form of cancer and 4th leading cause of cancer-related deaths worldwide. Due to the late stage of diagnosis, gastric cancer carries poor prognosis and poor overall survival. Infection with H. pylori is the strongest known risk factor. Fibroblast Growth Factor Receptor 4 (FGFR4) belongs to a family of highly conserved tyrosine kinases. This study investigated the molecular mechanism of FGFR4 regulation in response to H. pylori infection. Methods and Results: Among all the FGFRs, FGFR4 mRNA expression level was the most significantly elevated in human gastric cancer samples as compared to normal samples, using Real-time qPCR. These results were confirmed using the TCGA and Geo database analysis, confirming that FGFR4 is highly expressed in gastric cancer. Using western blot, we found that FGFR4 is significantly expressed in dysplasia and adenocarcinoma lesions in the TFF1-KO gastric cancer mouse model. Following infection with H. pylori in in-vitro (J166, 7.13) and in-vivo (PMSS1) models, we detected a significant increase in the expression of FGFR4 at the protein and mRNA levels. We also detected activation of STAT3 in human gastric cell lines and mice gastric tissues. Furthermore, analysis of FGFR4 promoter revealed several putative binding sites for STAT3. To confirm that FGFR4 expression is dependent upon STAT3 activation, we performed ChIP assay and confirmed direct functional binding of STAT3 on FGFR4 promoter. Using the FGF19, the ligand for FGFR4, we found that FGF19-FGFR4 axis played a vital role in activating STAT3 through an SRC-dependent mechanism and discovered that there is a feedforward activation loop between FGFR4 and STAT3. Functionally, we found that FGFR4 protected against H. pylori-induced DNA damage and cell death. Conclusion: Our study established a feedforward activation loop between FGFR4 and STAT3 in response to H. pylori infection and FGFR4 could be a possible druggable moiety for future therapies in gastric cancer. Citation Format: Nadeem S. Bhat, Mohammed Soutto, Xing Zhang, Zheng Chen, Shoumin Zhu, Heng Lu, Dunfa Peng, Zekuan Xu, Wael El-Rifai. Activation of STAT3 is mediated by FGFR4 induction via SRC signaling after H. pylori infection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5849.

Exploratory analysis on crosstalk between intra-tumor immunity and FGF/FGFR pathway in clear cell renal cell carcinoma.

e16525 Background: Clear cell renal cell carcinoma (ccRCC) patients classically show good response to VEGFR inhibitors; however, the biological basis by which FGFR inhibition provides tumor response was not well understood. Here, we performed an exploratory analysis of the relationship between the FGF/FGFR pathway and intra-tumor immunity to support the effectiveness of FGFR inhibitors for ccRCC. Methods: We used whole transcriptome data and immunohistochemistry with metastatic clear cell RCC specimens from patients who were treated at the Yamagata University Hospital (n = 57). FFPE samples were prepared from the primary lesions of treatment-naive metastatic ccRCC patients. FFPE was sliced by a pathologist to evaluate the immunological microenvironment. RNA extraction and immunostaining were performed at the same site. Immuno-histological quantification was performed by automatically analysis system HALO in digital whole slide imaging. Hierarchical clustering was performed, and the cohort was divided based on the profile of the FGF and immune cells. We analyzed the cancer-specific survival based on the FGF cluster classification and investigated the relationship between FGF-FGFR expression and immune cell infiltration that were evaluated histologically. Results: RNA transcriptome data showed that FGF2 and FGF7 were widely expressed in ccRCC. Hierarchical cluster analysis based on the FGF expression profile (intrinsic FGFs were excluded) revealed that metastatic ccRCC had three distinct patterns. Cluster1 showed low FGFs expression, except for FGF2 and 7, while Cluster2 and 3 expressed multiple FGFs. Survival analysis showed Cluster2and 3 had a poor cancer-specific survival rate than Cluster1 (Logrank test, p = 0.05). However, no association was detected between the FGF cluster classification and the infiltration of immune cell count in immunohistological analysis. In comparison of the expression of each FGF subfamily and the positive cells of CD4, CD8, CD68 and CD31 (Mann–Whitney U test, p &lt; 0.05), CD4 and CD8 were higher in the cases expressing FGF20. While most FGF subfamilies have been suggested to be less associated with immune cell infiltration (excluding FGF20), further analysis among FGF receptor expression and immune signatures are ongoing. Conclusions: Our study demonstrates the possibility of intra-tumor interaction between FGF/FGFR axis and immune infiltration in ccRCC.

Ferroptosis is induced by lenvatinib through fibroblast growth factor receptor-4 inhibition in hepatocellular carcinoma.

The tyrosine kinase inhibitor lenvatinib is used to treat advanced hepatocellular carcinoma (HCC). Ferroptosis is a type of cell death characterized by the iron‐dependent accumulation of lethal lipid reactive oxygen species (ROS). Nuclear factor erythroid‐derived 2‐like 2 (Nrf2) protects HCC cells against ferroptosis. However, the mechanism of lenvatinib‐induced cytotoxicity and the relationships between lenvatinib resistance and Nrf2 are unclear. Thus, we investigated the relationship between lenvatinib and ferroptosis and clarified the involvement of Nrf2 in lenvatinib‐induced cytotoxicity. Cell viability, lipid ROS levels, and protein expression were measured using Hep3B and HuH7 cells treated with lenvatinib or erastin. We examined these variables after silencing fibroblast growth factor receptor‐4 (FGFR4) or Nrf2 and overexpressing‐Nrf2. We immunohistochemically evaluated FGFR4 expression in recurrent lesions after resection and clarified the relationship between FGFR4 expression and lenvatinib efficacy. Lenvatinib suppressed system Xc − (xCT) and glutathione peroxidase 4 (GPX4) expression. Inhibition of the cystine import activity of xCT and GPX4 resulted in the accumulation of lipid ROS. Silencing‐FGFR4 suppressed xCT and GPX4 expression and increased lipid ROS levels. Nrf2‐silenced HCC cells displayed sensitivity to lenvatinib and high lipid ROS levels. In contrast, Nrf2‐overexpressing HCC cells displayed resistance to lenvatinib and low lipid ROS levels. The efficacy of lenvatinib was significantly lower in recurrent HCC lesions with low‐FGFR4 expression than in those with high‐FGFR4 expression. Patients with FGFR4‐positive HCC displayed significantly longer progression‐free survival than those with FGFR4‐negative HCC. Lenvatinib induced ferroptosis by inhibiting FGFR4. Nrf2 is involved in the sensitivity of HCC to lenvatinib.

Profiling the Biological Characteristics and Transitions through Upper Tract Tumor Origin, Bladder Recurrence, and Muscle-Invasive Bladder Progression in Upper Tract Urothelial Carcinoma.

To evaluate biological characteristics and transitions of upper tract urothelial carcinoma (UTUC) through metachronous bladder tumors after radical nephroureterectomy (RNU), we conducted immunohistochemical (IHC) staining of tumor specimens of UTUC tumor origin, non-muscle-invasive bladder cancer (NMIBC) and MIBC progressed after intravesical recurrence (IVR), and bladder primary MIBC. Fibroblast growth factor receptor 3 (FGFR3), p53, cytokeratin 5/6 (CK5/6), and CK20 were stained to examine expression rates. After expression assessment with heatmap clustering, the overexpression of four biomarkers from UTUC origin to metachronous MIBC progression was analyzed with clinicopathological variables. We found that high CK20 and low CK5/6 expression were both observed in UTUC tumor origin and subsequent NMIBC after RNU. By investigating molecular expression in the IVR specimen, we observed that low pT stage bladder recurrence occupied the majority of CK20 high CK5/6 low expression, but would change to CK20 low CK5/6 high expression as it progressed to MIBC. UTUC metachronous MIBC has different characteristics compared with bladder primary MIBC, which comprises favorable biological features such as high FGFR3 expression, and follows favorable prognosis compared to those without FGFR3 expression. The present study demonstrated that the biological characteristics of UTUC tumor origin shifts from luminal to basal-like features with progression to MIBC, but FGFR3 expression taken over from UTUC origin may comprise a favorable entity compared to primary MIBC.

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.

LncR-133a Suppresses Myoblast Differentiation by Sponging miR-133a-3p to Activate the FGFR1/ERK1/2 Signaling Pathway in Goats.

Long noncoding RNAs (lncRNAs) are involved in a variety of biological processes and illnesses. While a considerable number of lncRNAs have been discovered in skeletal muscle to far, their role and underlying processes during myogenesis remain mostly unclear. In this study, we described a new functional lncRNA named lncR-133a. Gene overexpression and interference studies in goat skeletal muscle satellite cells (MuSCs) were used to establish its function. The molecular mechanism by which lncR-133a governs muscle differentiation was elucidated primarily using quantitative real-time PCR (qRT-PCR), Western blotting, dual-luciferase activity assays, RNA immunoprecipitation, biotin-labeled probe, and RNA fluorescence in situ hybridization analyses. LncR-133a was found to be substantially expressed in longissimus thoracis et lumborum muscle, and its expression levels changed during MuSC differentiation in goats. We validated that lncR-133a suppresses MuSC differentiation in vitro. Dual-luciferase reporter screening, Argonaute 2 (AGO2) RNA immunoprecipitation assays, biotin-labeled lncR-133a capture, and fluorescence in situ hybridization showed that lncR-133a interacted with miR-133a-3p. Additionally, miR-133a-3p facilitated MuSC differentiation, but lncR-133a reversed this effect. The luciferase reporter assay and functional analyses established that miR-133a-3p directly targets fibroblast growth factor receptor 1 (FGFR1). Moreover, lncR-133a directly reduced miR-133a-3p’s capacity to suppress FGFR1 expression, and positively regulated the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). In summary, our results suggested that lncR-133a suppresses goat muscle differentiation by targeting miR-133a-3p and activating FGFR1/ERK1/2 signaling pathway.

FGFR3 Nuclear Translocation Contributes to Proliferative Potential and Poor Prognosis in Pancreatic Ductal Adenocarcinoma.

Fibroblast growth factor receptor 3 (FGFR3) was revealed to have divergent, even opposite roles in different neoplasms. In pancreatic ductal adenocarcinoma (PDAC), its impact on biological behavior and prognosis was not well elucidated. Fibroblast growth factor receptor 3 was downregulated by RNA interference to explore its impact on cell proliferative proclivity in PDAC cells. Furthermore, tissue microarray-based immunohistochemistry for FGFR3 was performed in 326 patients with PDAC who underwent radical resection, and its clinicopathologic and prognostic implications were then evaluated. First, successful FGFR3 knockdown remarkably decreased its expression, cell proliferation, and S-phase ratio in the cell cycle in 2 PDAC cell lines, BxPC-3 and AsPC-1. Meanwhile, alterations in p-Akt, cyclin D1, cyclin B1, and p21 were also observed. Subsequently, high nuclear FGFR3 expression, but not cytoplasmic, was significantly common in tumor tissues and positively associated with N stage and dismal overall survival in the entire cohort. In addition, nuclear FGFR3 expression was also prognostic in 10 of 14 subsets. Univariate and multivariate Cox regression analyses identified nuclear expression of FGFR3 as an independent prognosticator in the entire cohort. Our data showed that FGFR3 nuclear translocation contributes to cell proliferative potential and predicts poor long-term prognosis in PDAC after surgical resection.

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).

Immunohistochemical Expression Pattern of FGFR1, FGFR2, RIP5, and HIP2 in Developing and Postnatal Kidneys of Dab1-/- (yotari) Mice.

This study aimed to explore how Dab1 gene functional silencing influences the spatial and temporal expression patterns of fibroblast growth factor receptor 1 (FGFR1), fibroblast growth factor receptor 2 (FGFR2), receptor-interacting protein kinase 5 (RIP5), and huntingtin-interacting protein 2 (HIP2) in the developing and postnatal kidneys of the yotari mice as potential determinants of normal kidney formation and function. Dab1−/− animal kidneys exhibit diminished FGFR1/FGFR2 expression in all examined developmental stages, whereas RIP5 cell immunoreactivity demonstrated negligible variation. The HIP2 expression revealed a discernible difference during the postnatal period, where we noted a significant decrease in almost all the observed kidney structures of yotari animals. An extracellular signal-regulated kinase (Erk1/2) and mammalian target of rapamycin (mTOR) expression in yotari kidneys decreased in embryonic and postnatal developmental phases for which we can hypothesize that the Erk1/2 signaling pathway in the yotari mice kidneys is dependent on Reelin with Dab1 only partially implicated in Reelin-mediated MEK/Erk1/2 activation. The impairment of FGFR1 and FGFR2 expression suggests the involvement of the observed markers in generating the CAKUT phenotype resulting in renal hypoplasia. Our study demonstrates the critical role of HIP2 in reducing cell death throughout nephrogenesis and maturation in wild-type mice and indicates a possible connection between decreased HIP2 expression in postnatal kidney structures and observed podocyte injury in yotari. Our results emphasize the crucial function of the examined markers throughout normal kidney development and their potential participation in kidney pathology and diagnostics, where they might serve as biomarkers and therapeutic targets.

LncRNA SNHG1 Promotes the Progression of Pancreatic Cancer by Regulating FGFR1 Expression via Competitively Binding to miR-497.

BackgroundLong noncoding RNA small nucleolar RNA host gene 1 (SNHG1) is dysregulated in a variety of tumors. However, little is known of its role in pancreatic cancer (PC).MethodsThe role of SNHG1 on PC cell proliferation, migration, invasion, apoptosis, and the epithelial-mesenchymal transition (EMT) were assessed in vitro using MTT, EDU, wound healing, and Transwell assays, as well as flow cytometry and western blotting. Luciferase reporter assay, western blotting, and qRT-PCR were used to examine SNHG1 regulation. Tumor growth in mice was also investigated.ResultsDownregulation of SNHG1 blocked cell proliferation, migration and invasion, and induced apoptosis in vitro, while also inhibiting the EMT, shown by changes in the biomarkers E-cadherin, N-cadherin, and Vimentin. The opposite results were observed on upregulation of SNHG1. In vivo experiments showed that downregulation of SNHG1 inhibited tumor development in nude mice. Furthermore, experiments investigating the regulatory mechanism of SNHG1 indicated that SNHG1 acted as a competitive endogenous RNA, positively regulating the expression of fibroblast growth factor receptor 1 (FGFR1) through sponging miR-497. Rescue experiments demonstrated that the effects of SNHG1 downregulation on PC cells were attenuated when simultaneously inhibiting the levels of miR-497.ConclusionsSNHG1 upregulates FGFR1 expression by sponging miR-497, which promotes the progression of PC. SNHG1 may thus be a novel target for treating PC.

Frequent FGFR1 hotspot alterations in driver-unknown low-grade glioma and mixed neuronal-glial tumors

PurposeLow-grade gliomas (LGG) and mixed neuronal-glial tumors (MNGT) show frequent MAPK pathway alterations. Oncogenic fibroblast growth factor receptor 1 (FGFR1) tyrosinase kinase domain has been reported in brain tumors of various histologies. We sought to determine the frequency of FGFR1 hotspot mutations N546 and K656 in driver-unknown LGG/MNGT and examined FGFR1 immunohistochemistry as a potential tool to detect those alterations.MethodsWe analyzed 476 LGG/MNGT tumors for KIAA-1549-BRAF fusion, IDH1/2, TERT promotor, NF1, H3F3A and the remaining cases for FGFR1 mutation frequency and correlated FGFR1 immunohistochemistry in 106 cases.Results368 of 476 LGG/MNGT tumors contained non-FGFR1 alterations. We identified 9 FGFR1 p.N546K and 4 FGFR1 p.K656E mutations among the 108 remaining driver-unknown samples. Five tumors were classified as dysembryoplastic neuroepithelial tumor (DNT), 4 as pilocytic astrocytoma (PA) and 3 as rosette-forming glioneuronal tumor (RGNT). FGFR1 mutations were associated with oligodendroglia-like cells, but not with age or tumor location. FGFR1 immunohistochemical expression was observed in 92 cases. FGFR1 immunoreactivity score was higher in PA and DNT compared to diffuse astrocytoma, but no correlation between FGFR1 mutation in tumors and FGFR1 expression level was observed.ConclusionFGFR1 hotspot mutations are the fifth most prevailing alteration in LGG/MNGT. Performing FGFR1 sequencing analysis in driver-unknown low-grade brain tumors could yield up to 12% FGFR1 N546/K656 mutant cases.

CircKCNN2 suppresses the recurrence of hepatocellular carcinoma at least partially via regulating miR-520c-3p/methyl-DNA-binding domain protein 2 axis.

BackgroundRecurrence is the major cause of hepatocellular carcinoma (HCC) death. We aimed to identify circular RNA (circRNA) with predictive and therapeutic value for recurrent HCC.MethodsTissue samples from recurrent and non‐recurrent HCC patients were subjected to circRNA sequencing and transcriptome sequencing. circKCNN2 was identified through multi‐omics analyses. The effects of circKCNN2 on HCC were evaluated in cells, animals, database of The Cancer Genome Atlas, and a cohort with 130 HCC patients. circRNA precipitation, chromatin immunoprecipitation assay, RNA pull‐down, luciferase assay, and cell experiments were applied to evaluate the interaction of circKCNN2 with miRNAs and proteins. The association between circKCNN2 and the therapeutic effect of lenvatinib was investigated in HCC cell lines and HCC tissue‐derived organoids.ResultsThe expression of circKCNN2 was downregulated in HCC tissues and predicted a favorable overall survival and recurrence‐free survival. The expression of circKCNN2 was positively correlated with the parental gene, potassium calcium‐activated channel subfamily N member (KCNN2). Nuclear transcription factor Y subunit alpha (NFYA) was proven to inhibit the promoter activity of KCNN2, downregulate the expression of KCNN2 and circKCNN2, and predict an unfavorable recurrence‐free survival. Ectopic expression of circKCNN2 inhibited HCC cell proliferation, colony formation, migration, and tumor formation in a mouse model. miR‐520c‐3p sponged by circKCNN2 could reverse the inhibitory effect of circKCNN2 on HCC cells and down‐regulate the expression of methyl‐DNA‐binding domain protein 2 (MBD2). The intratumoral expression of MBD2 predicted a favorable recurrence‐free survival. circKCNN2 down‐regulated the expression of fibroblast growth factor receptor 4 (FGFR4), which can be reversed by miR‐520c‐3p and knockdown of MBD2. Lenvatinib inhibited the expression of FGFR4 and upregulated the expression of circKCNN2 and MBD2. Ectopic expression of circKCNN2 in HCC cells enhanced the therapeutic effect of lenvatinib. However, the high inherent level of circKCNN2 in HCC cells was associated with lenvatinib resistance.ConclusionscircKCNN2, transcriptionally repressed by NFYA, suppresses HCC recurrence via the miR‐520c‐3p/MBD2 axis. Inherent level of circKCNN2 in HCC cells predisposes anti‐tumor effect of lenvatinib possibly because both circKCNN2 and lenvatinib repress the expression of FGFR4. circKCNN2 may be a promising predictive biomarker and therapeutic agent for HCC recurrence.