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Background Chronic obstructive pulmonary disease (COPD) is characterized by incomplete reversible airflow limitation and chronic inflammatory response lesions. This study mainly explored whether FGFR2 and MGAT5 polymorphisms affected the risk of COPD in the Chinese people. Methods Five variants in FGFR2 and MGAT5 were chosen and genotyped using Agena MassARRAY platform from 315 COPD patients and 314 healthy controls. The correlation of FGFR2 and MGAT5 with COPD susceptibility was evaluated with odds ratio (OR) and 95% confidence interval (CI) via logistic regression. Results We found rs2420915 enhanced the risk of COPD, while rs6430491, rs2593704 reduced the susceptibility of COPD (p p MGAT5-rs2593704 played a protective role in COPD development in different subgroups (age ≤ 70, male, smokers, and individuals with BMI ≤ 24 kg/m2). Meanwhile, rs6430491 was linked with a lower risk of COPD in nonsmoking and BMI ≤ 24 kg/m2 subgroups. Conclusions We concluded that FGFR2 and MGAT5 genetic polymorphisms are correlated with the risk of COPD in the Chinese people. These data underscored the important role of FGFR2 and MGAT5 gene in the occurrence of COPD and provided new biomarkers for COPD treatment. Trial registration: NA.

BACKGROUND Most cases of Apert syndrome (AS) are found after birth. Cases of AS diagnosed by ultrasound combined with magnetic resonance imaging (MRI) and whole exome sequencing (WES) during pregnancy are rare. CASE SUMMARY We present the case of a 34-year old female patient (gravida 2, para 1) whose fetus was diagnosed with AS during pregnancy. Fetal ultrasound performed at 30, 2/7 wk of pregnancy showed abnormalities. MRI and three-dimensional ultrasound performed at 31, 1/7 wk of pregnancy showed the possibility of AS. Chromosome examination and core family WES were conducted at 31, 5/7 wk of pregnancy. The results showed that FGFR2 in the fetus had a c.755C>G missense mutation in its nucleotide, and AS was confirmed. CONCLUSION This case highlights the importance of imaging examinations. Prenatal ultrasound combined with MRI can identify fetal morphological abnormalities accurately, which can be confirmed by WES.

Dong-Wei Fu, Ai-Chun Liu Department of Hematology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang 150081, People’s Republic of ChinaCorrespondence: Ai-Chun LiuDepartment of Hematology, Harbin Medical University, Cancer Hospital, Harbin, Heilongjiang 150081, People’s Republic of ChinaEmail liuaichun93@163.comPurpose: Currently, there is no efficient and feasible method for diffuse large B-cell lymphoma (DLBCL) in clinical practice, and the main reason is the unclear pathogenesis of DLBCL, which leads to a high fatality rate of DLBCL.Methods: Therefore, it is meaningful to explore the molecular mechanism of DLBCL and find a targeted therapeutic approach from the molecular level.Results: Long non-coding RNA (lncRNA) SBF2-AS1 was highly expressed in DLBCL tissues and cell lines. Silencing of SBF2-AS1 inhibited the viability and growth of OCI-LY-3 cells. Furthermore, SBF2-AS1 acted as a sponge of miR-494-3p and inhibited its expression. And miR-494-3p directly targeted FGFR2. Functionally, forced expression of miR-494-3p or knockdown of FGFR2 removed the promoted effects of lncRNA SBF2-AS1 on DLBCL development. In vivo tumorigenesis experiments indicated SBF2-AS1 accelerated tumor growth via miR-494-3p/FGFR2 axis.Conclusion: Our study revealed that SBF2-AS1 promoted the growth of DLBCL, which were mediated by miR-494-3p/FGFR2 axis.Keywords: diffuse large B-cell lymphoma, SBF2-AS1, miR-494-3p, FGFR2, tumorigenesis

Introduction: Biliary tract cancers (BTCs) are poor prognosis malignancies usually classified in intrahepatic cholangiocarcinoma (iCCA), extrahepatic cholangiocarcinoma, gallbladder cancer, and ampulla of Vater cancer. In the last few years, novel treatment targets have been identified in iCCA patients, including fibroblast growth factor receptor (FGFR) aberrations; thus, several FGFR inhibitors are currently being developed, some of which have already suggested interesting efficacy and adequate safety in phase I and phase II trials regarding refractory iCCA. Areas covered: This review provides an overview regarding the current scenario of FGFR2 targeted therapies in iCCA, especially focusing on the mechanism of action and clinical development of futibatinib (TAS-120), a highly selective irreversible pan-FGFR antagonist. According to the interim analysis of the FOENIX-CCA2 trial, whose results have been presented at the 2020 American Society of Clinical Oncology (ASCO) Annual Meeting, futibatinib could lead to meaningful benefit in patients affected by previously treated iCCA with FGFR2 gene fusions or other rearrangements. Expert opinion: Because of its promising and durable activity, futibatinib has the potential to become a novel therapeutic option in the treatment of iCCAs harboring FGFR2 aberrations. Further studies are warranted to confirm the efficacy of this investigational molecule.

Fibroblast growth factor receptor (FGFR) is associated with proliferation, migration, and angiogenesis of carcinomas, and FGFR signaling inhibitors are considered a key drug for the treatment of solid tumors with FGFR overexpression. Amplification of FGFR2 is reportedly identified in 3%‐10% of gastric cancers (GCs). The aim of this study is to clarify whether the identification of the circulating tumor cells (CTCs) with FGFR2 overexpression is useful to detect patients with FGFR2‐overexpressing GC. One hundred GC patients who underwent gastrectomy were enrolled. A total volume of 8 mL of peripheral blood was collected from each patient just before gastrectomy, and mononuclear cells were enriched by Ficol density gradient centrifugation. These cells were immunostained with PI/CD45/EpCAM/FGFR2. The number of CTCs with FGFR2 expression in each sample was enumerated by FACScan. The FGFR2 expression level of the resected primary tumor was assessed by immunohistochemistry. The number of FGFR2‐positive CTCs in the GC patients' peripheral blood was significantly correlated with the FGFR2 expression level of the primary GC. The relapse‐free survival of the patients with FGFR2‐positive CTCs (≥5 cells/10 mL blood) was significantly poorer (P = .018, log‐rank) than that of the patients without FGFR2‐positive CTCs (, We aim to clarify the clinical significance of FGFR2‐positive CTCs in gastric cancer. FGFR2‐positive CTCs were correlated with the FGFR2 expression level of primary GC. The detection of FGFR2‐positive CTCs might help identify an existing FGFR2‐positive tumor.

Cholangiocarcinoma is a very heterogenous cancer and “target-rich” disease. While the current classifications are based on the anatomic location of these tumors (intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, and gallbladder cancer), tumors within and across these disease groups have unique and often mutually exclusive molecular aberrations. Amongst these, fibroblast growth factor receptor 2 (FGFR2) fusion is one of the first amongst the list of “actionable” targets for which the US Food and Drug Administration just approved pemigatinib. This is for patients with cholangiocarcinoma who have received prior treatment and have FGFR2 fusion or another rearrangement. This was based on the results from the clinical trial FIGHT-202 (NCT02924376). At present, several FGFR inhibitors are actively being tested in several agnostic and tumor-specific clinical trials. Patients also have had the opportunity of getting access to some of these oral drugs through compassionate use programs. As a consequence, these patients have more options in addition to chemotherapy. These all tend to have “good” initial responses and improvement in performance status and later “acquired” mechanisms of resistance. The latter tend to often be gatekeeper mutations that bypass the inhibitory effects of these selective FGFR inhibitors and/or cause steric hindrance. These tumors, therefore, evolve on selective pressure (temporal heterogeneity). This can be captured noninvasively using “liquid biopsies” (circulating tumor DNA testing). Here we present cases (several years into treatment on average) showing the feasibility of using liquid biopsies (ctDNA testing) as well as the gain and later potential loss of intratumoral and temporal heterogeneity exhibited under selective pressure of these novel FGFR inhibitors, chemotherapy and/or locoregional therapies. Despite limitations in sample size and provider bias, it is important to identify these “exceptional responders” and/or better outcomes that may be inherent to the biology of FGFR fusion-positive cholangiocarcinomas.

Rationale: The formation of adipose-derived stem cells (ASCs) into spheres on a chitosan-coated microenvironment promoted ASCs differentiation into a mixed population of neural lineage-like cells (NLCs), but the underline mechanism is still unknown. Since the fibroblast growth factor 9 (FGF9) and fibroblast growth factor receptors (FGFRs) play as key regulators of neural cell fate during embryo development and stem cell differentiation, the current study aims to reveal the interplay of FGF9 and FGFRs for promoting peripheral nerve regeneration. Methods: Different concentration of FGF9 peptide (10, 25, 50, 100 ng/mL) were added during NLCs induction (FGF9-NLCs). The FGFR expressions and potential signaling were studied by gene and protein expressions as well as knocking down by specific FGFR siRNA or commercial inhibitors. FGF9-NLCs were fluorescent labeled and applied into a nerve conduit upon the injured sciatic nerves of experimental rats. Results: The FGFR2 and FGFR4 were significantly increased during NLCs induction. The FGF9 treated FGF9-NLCs spheres became smaller and changed into Schwann cells (SCs) which expressed S100β and GFAP. The specific silencing of FGFR2 diminished FGF9-induced Akt phosphorylation and inhibited the differentiation of SCs. Transplanted FGF9-NLCs participated in myelin sheath formation, enhanced axonal regrowth and promoted innervated muscle regeneration. The knockdown of FGFR2 in FGF9-NLCs led to the abolishment of nerve regeneration. Conclusions: Our data therefore demonstrate the importance of FGF9 in the determination of SC fate via the FGF9-FGFR2-Akt pathway and reveal the therapeutic benefit of FGF9-NLCs.

Objectives: Breast cancer tend to be more progressive with poorer prognosis in younger patients than those at an older age. Single Nucleotide Polymorphisms (SNPs) of P53 Pro72Arg, MDM2 SNP309, P21 Ser31Arg, ER SNP594, HER2 Ile655Val, and FGFR2 rs2981582 have drawn attention as genetic factors associated with cancer risk. However, there were contradictory results involving different races and their association is still unknown in Indonesian populations. This study was performed to examine the proportion of these six genes polymorphisms and their associations with age of onset of breast cancer patients in Yogyakarta, Indonesia. Methods: Biorepository DNA from 199 patients registered at Dr. Sardjito Hospital Yogyakarta from 2006-2013 were tested for polymorphisms using the PCR-RFLP method. Samples were taken from two age groups; early-onset (55 years). Chi-square tests with odds ratio were used for data analysis. Results: The mean age of the early-onset group was 36±4.2 years, while the late-onset group was 62±6.9 years. AA genotype and A allele of P21 and TT genotypes and T allele of FGFR2 were significantly more frequent and were associated with an increased risk of early-onset of breast cancer (95%CI: 2.54 and 1.59; 2.63 and 1.64, respectively). Conclusions: Our study indicates that the A allele of P21 and the allele T of FGFR2 may be associated with an increased risk of early-onset of breast cancer in Yogyakarta, Indonesia. Further analysis is needed to confirm the findings.

Background Crouzon syndrome (CS), which results from fibroblast growth factor receptor 2 mutations, is associated with craniosynostosis, exophthalmos, and other symptoms. Herein, we report the genetic abnormalities detected in a Chinese family with autosomal dominant CS, combined with luxation of the eyeball. This luxation was a consequence of the trauma to the shallow orbits. Case presentation The proband was a 4-year-old boy. He accidentally fell, following which luxation of the bulbus oculi occurred immediately. Computed tomography and magnetic resonance imaging clearly revealed ocular proptosis. Upon physical examination, the proband, his father, and grandfather had ocular proptosis, shallow orbits, and mid-face hypoplasia. However, their hands and feet were clinically normal. Genomic DNA was extracted from the peripheral blood through a polymerase chain reaction performed for the target sequence. Genetic assessments revealed a heterozygous missense mutation (c.1012G > C, p.G338R) in exon 10 of the human FGFR2, cosegregated with the disease phenotype in this family. These findings confirmed the diagnosis of CS. Discussion CS is usually caused by FGFR2 mutations. While there are a few reports of luxation of the bulbus oculi in Chinese families with CS, the ocular proptosis, shallow orbits, combined with luxation of eyeball after trauma observed in this patient were particularly interesting. Our findings enhance the current knowledge of traumatic luxation concomitant with CS.

Objective Breast cancer (BC) is a common malignancy among women worldwide. Fibroblast growth factor receptor 2 (FGFR2) rs2981582 is reported to play a vital role in BC development. However, the relationship between them remains unclear. Methods Ninety-five patients and 140 healthy controls were enrolled in the study. Plasma DNA was genotyped by the MassARRAY method. A meta-analysis was conducted to clarify the effect of FGFR2 polymorphism on BC risk. Results Our case-control study results revealed a significant difference in CC, TC, and TT genotypes between patients and controls. Logistic regression analysis showed that TT and TC genotype and the dominant mode were significantly correlated with BC development [odds ratio (OR) = 1.21, 95% confidence interval (CI): 1.050–2.27; OR = 1.81, 95% CI: 1.24–2.73; OR = 2.15, 95% CI: 1.25–5.31, respectively], even after adjusting for age, body weight, drinking, smoking, and estrogen receptor status. A meta-analysis of 15 studies showed significant differences among the dominant, recessive, heterozygote, and homozygote models between patients and controls. Conclusions Our results showed an association of FGFR2 rs2981582 polymorphism with BC in an Asian population. However, a more comprehensive study of the relationship between the polymorphism and BC is still needed.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide–drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide–drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B–DM1 can be developed into a potential PDC for tumor treatment in the future.

Simple Summary In this work, we checked the modulation of Fibroblast Growth Factor Receptors (FGFRs) along with differentiation-related and epithelial-to-mesenchymal transition (EMT)-related markers to identify expression profiles that could be predictive for actinic keratosis (AK) progression through the “differentiated” pathway. We found that the downregulation of the analyzed differentiation markers, but not the modulation of the EMT-related markers, correlated with the canonical progression of AK. In addition, the observed modulation of FGFR2 mesenchymal/epithelial isoforms compatible with FGFR2 isoform switch, as well as the upregulation of FGFR4 suggested their correlation with early steps of AK pathogenesis. In contrast, the increase of mesenchymal FGFR3c isoform expression appeared to suggest that this event correlated with late steps of AK progression. In addition, the strong modulation of filaggrin (FIL), Snail1, as well as of FGFR2c, FGFR4, and their ligand Fibroblast Growth Factor 2 (FGF2), observed in some of the keratinocytic intraepithelial neoplasia grade I (KIN I) samples, may indicate that they could be molecular markers predictive for those KIN I lesions destined to a direct progression to squamous cell carcinoma (SCC) through the “differentiated” pathway. Abstract Actinic keratosis (AK) is the ultra violet (UV)-induced preneoplastic skin lesion clinically classified in low (KIN I), intermediate (KIN II), and high (KIN III) grade lesions. In this work we analyzed the expression of Fibroblast Growth Factor Receptors (FGFRs), as well as of keratinocyte differentiation and epithelial-to-mesenchymal transition (EMT)-related markers in differentially graded AK lesions, in order to identify specific expression profiles that could be predictive for direct progression of some KIN I lesions towards squamous cell carcinoma (SCC). Our molecular analysis showed that the keratinocyte differentiation markers keratin 1 (K1), desmoglein-1 (DSG1), and filaggrin (FIL) were progressively downregulated in KIN I, II, and III lesions, while the modulation of epithelial/mesenchymal markers and the induction of the transcription factors Snail1 and Zinc finger E-box-binding homeobox 1 (ZEB1) compatible with pathological EMT, even if observable, did not appear to correlate with AK progression. Concerning FGFRs, a modulation of epithelial isoform of FGFR2 (FGFR2b) and the mesenchymal FGFR2c isoform compatible with an FGFR2 isoform switch, as well as FGFR4 upregulation were observed starting from KIN I lesions, suggesting that they could be events involved in early steps of AK pathogenesis. In contrast, the increase of FGFR3c expression, mainly appreciable in KIN II and KIN III lesions, suggested a correlation with AK late progression. Interestingly, the strong modulation of FIL, Snail1, as well as of FGFR2c, FGFR4, and of their ligand FGF2, observed in some of the KIN I samples, may indicate that they could be molecular markers predictive for those low graded lesions destined to a direct progression to SCC. In conclusion, our data point on the identification of molecular markers predictive for AK rapid progression through the “differentiated” pathway. Our results also represent an important step that, in future, will help to clarify the molecular mechanisms underlying FGFR signaling deregulation in epithelial tissues during the switch from the pre-neoplastic to the oncogenic malignant phenotype.

We present here an assessment of a &lsquo, real-life&rsquo, value of automated machine learning algorithm (AI) for examination of immunohistochemistry for fibroblast growth factor receptor-2 (FGFR2) in breast cancer (BC). Expression of FGFR2 in BC (n = 315) measured using a certified 3DHistech CaseViewer/QuantCenter software 2.3.0. was compared to the manual pathologic assessment in digital slides (PA). Results revealed: (i) substantial interrater agreement between AI and PA for dichotomized evaluation (Cohen&rsquo, s kappa = 0.61), (ii) strong correlation between AI and PA H-scores (Spearman r = 0.85, p &lt, 0.001), (iii) a small constant error and a significant proportional error (Passing&ndash, Bablok regression y = 0.51 &times, X + 29.9, p &lt, (iv) discrepancies in H-score in cases of extreme (strongest/weakest) or heterogeneous FGFR2 expression and poor tissue quality. The time of AI was significantly longer (568 h) than that of the pathologist (32 h). This study shows that the described commercial machine learning algorithm can reliably execute a routine pathologic assessment, however, in some instances, human expertise is essential.

Purpose Various aberrations in the fibroblast growth factor receptor genes FGFR1, FGFR2, and FGFR3 are found in different cancers, including breast cancer (BC). This study analyzed the impact of FGFR amplification on the BC prognosis. Methods The study included 894 BC patients. The amplification rates of FGFR1, FGFR2, and FGFR3 were evaluated on tissue microarrays using fluorescence in situ hybridization (FISH). Associations between these parameters and prognosis were analyzed using multivariate Cox regression analyses. Results FGFR1 FISH was assessable in 503 samples, FGFR2 FISH in 447, and FGFR3 FISH in 562. The FGFR1 amplification rate was 6.6% (n = 33). Increased FGFR2 copy numbers were seen in 0.9% (n = 4); only one patient had FGFR3 amplification (0.2%). Most patients with FGFR1 amplification had luminal B-like tumors (69.7%, n = 23); only 32.6% (n = 153) of patients without FGFR1 amplification had luminal B-like BC. Other patient and tumor characteristics appeared similar between these two groups. Observed outcome differences between BC patients with and without FGFR1 amplification did not achieve statistical significance; however, there was a trend toward poorer distant metastasis-free survival in BC patients with FGFR1 amplification (HR = 2.08; 95% CI 0.98 to 4.39, P = 0.05). Conclusion FGFR1 amplification occurs most frequently in patients with luminal B-like BC. The study showed a nonsignificant correlation with the prognosis, probably due to the small sample size. Further research is therefore needed to address the role of FGFR1 amplifications in early BC patients. FGFR2 and FGFR3 amplifications are rare in patients with primary BC.

Interaction between fibroblast growth factor receptor 2 (FGFR2) and estrogen/progesterone receptors (ER/PR) affects resistance to anti-ER therapies, however the prognostic value of FGFR2 in breast cancer (BCa) remains largely unexplored. We have recently showed in vitro that FGFR2-mediated signaling alters PR activity and response to anti-ER treatment. Herein, prognostic significance of FGFR2 in BCa was evaluated in relation to both ER/PR protein status and a molecular signature designed to reflect PR transcriptional activity. FGFR2 was examined in 353 BCa cases using immunohistochemistry and Nanostring-based RNA quantification. FGFR2 expression was higher in ER+PR+ and ER+PR- compared to ER&minus, PR&minus, cases (p &lt, 0.001). Low FGFR2 was associated with higher grade (p &lt, 0.001), higher Ki67 proliferation index (p &lt, 0.001), and worse overall and disease-free survival (HR = 2.34 (95% CI: 1.26&ndash, 4.34), p = 0.007 and HR = 2.22 (95% CI: 1.25&ndash, 3.93), p = 0.006, respectively). The poor prognostic value of low FGFR2 was apparent in ER+PR+, but not in ER+PR&minus, patients, and it did not depend on the expression level of PR-dependent genes. Despite the functional link between FGFR2 and ER/PR revealed by preclinical studies, the data showed a link between FGFR2 expression and poor prognosis in BCa patients.

Objective In Jordan, breast cancer (BC) affects a substantial proportion of Jordanian women, highlighting the need for studies to be carried out regarding the genetic component of the disease. The aim of the present study was to investigate the interaction between BC risk and prognosis and polymorphisms in genes (ATM, CASP8, FGFR2, FN1, IGF1, LSP1, MAP3K, MMP7, and RHOC) that were chosen for this study previously reported as having a role in the disease. Materials and methods Blood samples were collected from 242 BC patients and 231 disease-free volunteers recruited from the Jordanian population. DNA was extracted from blood and each sample was sent to the Australian Genome Research Facility for genotyping. Results The rs1219648 SNP of the FGFR2 gene was the only investigated variant to show any direct association with BC in Jordanian women (p-value = 0.04). However, the CASP8rs6760993 SNP was found to be significantly associated with BC (p-value = 0.04) when using the dominant model. Other gene polymorphisms showed varying levels of association between some investigated SNPs and different BC risk and prognostic factors. Conclusion Despite reports to the contrary in other populations, most of the investigated genes and their respective SNPs did not show any significant association with BC in Jordanian women. Our results underline the need for independent BC research to be carried out in the Jordanian population to decipher the genetic basis of the disease. .

Fibroblast growth factor receptor 2 (FGFR2) gene fusions are bona fide oncogenic drivers in 10&ndash, 15% of intrahepatic cholangiocarcinoma (CCA), yet currently there are no cell lines publically available to study endogenous FGFR2 gene fusions. The ability of clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 to generate large yet precise chromosomal rearrangements has presented the possibility of engineering endogenous gene fusions for downstream studies. In this technical report, we describe the generation of an endogenous FGFR2&ndash, Bicaudal family RNA binding protein 1 (BICC1) fusion in multiple independent cholangiocarcinoma and immortalized liver cell lines using CRISPR. BICC1 is the most common FGFR2 fusion partner in CCA, and the fusion arises as a consequence of a 58-megabase-sized inversion on chromosome 10. We replicated this inversion to generate a fusion product that is identical to that seen in many human CCA. Our results demonstrate the feasibility of generating large megabase-scale inversions that faithfully reproduce human cancer aberrations.

Yun Jiang,1 Zhancheng Wang,1 Xu Chen,1 Wei Wang,1 Xiaowei Wang2 1Department of Cardiology, The Eighth People’s Hospital of Shanghai, Shanghai 200233, China; 2Shanghai Weiang Info Tech Ltd., Shanghai 200233, China Background: The adenosine deaminase acting on RNA 1 (ADAR1) specifically deaminates adenosine to inosine in double-stranded RNA (dsRNA). Emerging evidence indicated that under hypoxia condition, such as tumor microenvironment, ADAR1 level was increased. Interestingly, we found FGFR2 was also increased under hypoxia stress. The purpose of this study was to investigate the regulation mechanism of ADAR1 and the potential role of ADAR1–FGFR2 axis in cell proliferation and apoptosis.Methods: Using human umbilical vein endothelial cells as cellular model, we explored the function of ADAR1 in regulating cell survival.Results: We found manipulation of FGFR2 activity could override the cellular effect of ADAR1, suggesting FGFR2 could be a potential effector of ADAR1. Moreover, our results revealed that PI3K-Akt pathway was involved in ADAR1–FGFR2 axis-induced cell proliferation.Conclusion: In summary, this study supported the notion that ADAR1 could play a role in tumor cell proliferation, which was mediated by FGFR2. Keywords: ADAR1, HUVEC, FGFR2, apoptosis, hypoxia, PI3K-Akt pathway

Apert syndrome (AS), the most severe form of craniosynostosis, is caused by missense mutations including Pro253Arg(P253R) of fibroblast growth factor receptor 2 (FGFR2), which leads to enhanced FGF/FGFR2-signaling activity. Surgical correction of the deformed skull is the typical treatment for AS. Because of constant maldevelopment of sutures, the corrective surgery is often executed several times, resulting in increased patient challenge and complications. Biological therapies targeting the signaling of mutant FGFR2 allele, in combination with surgery, may bring better outcome. Here we screened and found a small interfering RNA (siRNA) specifically targeting the Fgfr2-P253R allele, and we revealed that it inhibited osteoblastic differentiation and matrix mineralization by reducing the signaling of ERK1/2 and P38 in cultured primary calvarial cells and calvarial explants from Apert mice (Fgfr2+/P253R). Furthermore, AAV9 carrying short hairpin RNA (shRNA) (AAV9-Fgfr2-shRNA) against mutant Fgfr2 was delivered to the skulls of AS mice. Results demonstrate that AAV9-Fgfr2-shRNA attenuated the premature closure of coronal suture and the decreased calvarial bone volume of AS mice. Our study provides a novel practical biological approach, which will, in combination with other therapies, including surgeries, help treat patients with AS while providing experimental clues for the biological therapies of other genetic skeletal diseases. Keywords: craniosynostosis, Apert syndrome, Fgfr2, adeno-associated virus, RNAi, molecular therapy

Fibroblast growth factor 9 (FGF9) promotes cancer progression; however, its role in cell proliferation related to tumorigenesis remains elusive. We investigated how FGF9 affected MA‐10 mouse Leydig tumor cell proliferation and found that FGF9 significantly induced cell proliferation by activating ERK1/2 and retinoblastoma (Rb) phosphorylations within 15 minutes. Subsequently, the expressions of E2F1 and the cell cycle regulators: cyclin D1, cyclin E1 and cyclin‐dependent kinase 4 (CDK4) in G1 phase and cyclin A1, CDK2 and CDK1 in S‐G2/M phases were increased at 12 hours after FGF9 treatment; and cyclin B1 in G2/M phases were induced at 24 hours after FGF9 stimulation, whereas the phosphorylations of p53, p21 and p27 were not affected by FGF9. Moreover, FGF9‐induced effects were inhibited by MEK inhibitor PD98059, indicating FGF9 activated the Rb/E2F pathway to accelerate MA‐10 cell proliferation by activating ERK1/2. Immunoprecipitation assay and ChIP‐quantitative PCR results showed that FGF9‐induced Rb phosphorylation led to the dissociation of Rb‐E2F1 complexes and thereby enhanced the transactivations of E2F1 target genes, Cyclin D1, Cyclin E1 and Cyclin A1. Silencing of FGF receptor 2 (FGFR2) using lentiviral shRNA inhibited FGF9‐induced ERK1/2 phosphorylation and cell proliferation, indicating that FGFR2 is the obligate receptor for FGF9 to bind and activate the signaling pathway in MA‐10 cells. Furthermore, in a severe combined immunodeficiency mouse xenograft model, FGF9 significantly promoted MA‐10 tumor growth, a consequence of increased cell proliferation and decreased apoptosis. Conclusively, FGF9 interacts with FGFR2 to activate ERK1/2, Rb/E2F1 and cell cycle pathways to induce MA‐10 cell proliferation in vitro and tumor growth in vivo.

Aim Male breast cancer (MBC) is a rare disease and recommendations for its clinical management are often extrapolated from those for female breast cancer, even if breast cancer (BC) has different characteristics in the two sexes. The purpose of this study was to assess the influence of several individual characteristics including clinico-pathological, lifestyle and genetic factors on overall survival (OS) of a relatively large and well characterized population-based series of 166 MBCs enrolled in Tuscany. Methods We genotyped MBC cases at BRCA1/2 genes and at 9 candidate BC susceptibility SNPs. Kaplan-Meier method and multivariate Cox regression, adjusted for several individual characteristics were used. To reduce a possible selection bias related to the interval between diagnosis and enrolment of MBC cases into the study, we used the date of blood donation as the date of the start of observation for survival analysis. Results Only smoking habits had a significant effect on OS at 10 years (for current smokers, HR: 3.34; 95% CI 1.45–7.68; p = 0.004), while lymph node status fell short of reaching statistical significance (for pN positive, HR: 2.07; 95% CI 0.93–4.55; p = 0.07). In the same multivariate analysis we found a significantly higher OS in cases with FGFR2 rs2981582 variant in the dominant transmission model (HR: 0.29; 95% CI: 0.13–0.62; p = 0.028). A sensitivity analysis with left truncation showed similar results. Conclusions Our results may contribute to shed light on factors influencing MBC survival suggesting an important role for cigarette smoking and FGFR2 rs2981582 variant, and provide clues for better patient management.

Fibroblast growth factor receptor 2 (FGFR2) was demonstrated to correlate to the progression and prognosis of intrahepatic cholangiocarcinoma (ICC) by numerous evidences. However, as a well‐recognized suppressor of FGFR2 signalling, the clinical significance of Sprouty (SPRY) family of ICC has not been investigated. In our study, the expressions of SPRY1‐4 in 20 pairs of fresh tumour tissues were detected with qPCR, and in 108 cases of paraffin‐embedded tissues with immunohistochemistry. The prognostic value of SPRY family in ICC was estimated with univariate analysis and multivariate analysis. As a result, SPRY2 was identified as an independent prognostic biomarker predicting favourable prognosis of ICC. High SPRY2 expression was correlated with good differentiation of ICC. With silencing SPRY2 expression, we demonstrated that SPRY2 could suppress FGFR2‐induced ERK phosphorylation, migration, invasion and epithelial‐mesenchymal transition (EMT) under FGF1 stimulation. By overexpressing SPRY2‐wide type or SPRY2‐Y55F, the tyrosine‐55 of SPRY2 was demonstrated to be essential in suppressing ERK phosphorylation, tumour invasion and EMT of ICC cells. In conclusion, SPRY2 was correlated with favourable prognosis of ICC via suppressing FGFR2‐induced ERK phosphorylation, invasion and EMT. The phosphorylation of SPRY2‐Y55 was required in this tumour‐suppressing function of SPRY2.

The aim of this study was to investigate the expression of FGF2 and FGFR2 in patients with idiopathic pulmonary fibrosis (IPF) and lung cancer (LC) as well as their clinical significance. Reverse transcription-quantitative PCR (RT-qPCR) and western blotting were used to detect FGF2 and FGFR2 expression in LC and adjacent normal tissues of LC patients and lavage fluid of idiopathic pulmonary fibers patients and normal controls (confirmed by bronchoalveolar lavage examination). The expression levels of FGF2 mRNA and protein in the non-small cell LC tissues were significantly higher than those in the adjacent normal tissues (P0.05), but were significantly correlated with lymph node metastasis, tumor differentiation and TNM staging. FGF2 and FGFR2 proteins were highly expressed in cancer tissues of LC patients and lavage fluid of patients with IPF. The expression of FGF2 mRNA and FGFR2 mRNA was correlated with lymph node metastasis and TNM stage. The high expression levels of FGF2 mRNA and FGFR2 mRNA were associated with tumor metastasis and poor prognosis of LC patients.

WOS: 000425647900009, PubMed ID: 29483804, Apert syndrome is an autosomal dominant craniosynostosis syndrome accompanied by limb anomalies. The fibroblast growth factor receptor 2 (FGFR2) gene is responsible for the disease and two different heterozygous mutations, p.Pro253Arg and p.Ser252Trp, have been defined as responsible in the majority of cases of Apert syndrome. In this case report, two patients with Apert syndrome with two different FGFR2 gene mutations are presented. Case-1, a 4-month-old boy with craniosynostosis and syndactyly was referred to pediatric genetic clinic. The molecular analysis revealed p.Pro253Arg mutation in the FGFR2 gene, which confirmed the diagnosis of Apert syndrome. Case-2, a 16-year-old girl with developmental delay, cleft palate, syndactyly, and craniosynostosis, was also diagnosed as having Apert syndrome. A molecular diagnosis identified a p.Ser252Trp heterozygous mutation in the FGFR2 gene. Case-1 underwent surgery for craniosynostosis at age 10 months and he was developmentally normal during the 2 year follow-up period. As a conclusion, early surgical intervention should be considered in cases of Apert syndrome to prevent intellectual disability.

The altered isoform switching of the fibroblast growth factor receptor 2 (FGFR2) and aberrant expression of the mesenchymal FGFR2c isoform in epithelial cells is involved in cancer progression. We have recently described that the ectopic expression of FGFR2c in normal human keratinocytes induces epithelial-mesenchymal transition and leads to invasiveness and anchorage-independent growth. Here, we extended our analysis to the effects of this FGFR2c forced expression on human keratinocyte differentiation and stratification. Our findings demonstrated that, differently from cells overexpressing the epithelial splicing variant FGFR2b, keratinocytes ectopically expressing FGFR2c are not able to form a monolayer and display decreased expression of early differentiation markers. This impaired ability to enter the differentiation program is related to the up-modulation of the transcription factor ΔNp63. In addition, FGFR2c-expressing keratinocytes undergo defective stratification and invasion of the collagen matrix in 3D organotypic cultures, further suggesting their tumorigenic potential. Taken together, our results support the hypothesis that the receptor switching and the consequent appearance of the mesenchymal FGFR2c variant in the epithelial context would drive early steps of carcinogenesis, unbalancing the p63/FGFR interplay, and altering the paracrine response to the microenvironment.

Cancer stem cells (CSCs), which have the potential for self-renewal, differentiation and de-differentiation, undergo epigenetic, epithelial-mesenchymal, immunological and metabolic reprogramming to adapt to the tumor microenvironment and survive host defense or therapeutic insults. Intra-tumor heterogeneity and cancer-cell plasticity give rise to therapeutic resistance and recurrence through clonal replacement and reactivation of dormant CSCs, respectively. WNT signaling cascades cross-talk with the FGF, Notch, Hedgehog and TGFβ/BMP signaling cascades and regulate expression of functional CSC markers, such as CD44, CD133 (PROM1), EPCAM and LGR5 (GPR49). Aberrant canonical and non-canonical WNT signaling in human malignancies, including breast, colorectal, gastric, lung, ovary, pancreatic, prostate and uterine cancers, leukemia and melanoma, are involved in CSC survival, bulk-tumor expansion and invasion/metastasis. WNT signaling-targeted therapeutics, such as anti-FZD1/2/5/7/8 monoclonal antibody (mAb) (vantictumab), anti-LGR5 antibody-drug conjugate (ADC) (mAb-mc-vc-PAB-MMAE), anti-PTK7 ADC (PF-06647020), anti-ROR1 mAb (cirmtuzumab), anti-RSPO3 mAb (rosmantuzumab), small-molecule porcupine inhibitors (ETC-159, WNT-C59 and WNT974), tankyrase inhibitors (AZ1366, G007-LK, NVP-TNKS656 and XAV939) and β-catenin inhibitors (BC2059, CWP232228, ICG-001 and PRI-724), are in clinical trials or preclinical studies for the treatment of patients with WNT-driven cancers. WNT signaling-targeted therapeutics are applicable for combination therapy with BCR-ABL, EGFR, FLT3, KIT or RET inhibitors to treat a subset of tyrosine kinase-driven cancers because WNT and tyrosine kinase signaling cascades converge to β-catenin for the maintenance and expansion of CSCs. WNT signaling-targeted therapeutics might also be applicable for combination therapy with immune checkpoint blockers, such as atezolizumab, avelumab, durvalumab, ipilimumab, nivolumab and pembrolizumab, to treat cancers with immune evasion, although the context-dependent effects of WNT signaling on immunity should be carefully assessed. Omics monitoring, such as genome sequencing and transcriptome tests, immunohistochemical analyses on PD-L1 (CD274), PD-1 (PDCD1), ROR1 and nuclear β-catenin and organoid-based drug screening, is necessary to determine the appropriate WNT signaling-targeted therapeutics for cancer patients.

Fibroblast growth factor receptor 2 (FGFR2) is a membrane-spanning tyrosine kinase that mediates signaling for FGFs. Recent studies detected various point mutations of FGFR2 in multiple types of cancers, including breast cancer, lung cancer, gastric cancer, uterine cancer and ovarian cancer, yet the casual relationship between these mutations and tumorigenesis is unclear. Here we will discuss possible interactions between FGFR2 signaling and several major pathways through which the aberrantly activated FGFR2 signaling may result in breast cancer development. We will also discuss some recent developments in the discovery and application of therapies and strategies for breast cancers by inhibiting FGFR2 activities.

Ionizing radiation (IR) and chemotherapy are standard of care treatments for glioblastoma (GBM) patients and both result in DNA damage, however, the clinical efficacy is limited due to therapeutic resistance. We identified a mechanism of such resistance mediated by phosphorylation of PTEN on tyrosine 240 (pY240-PTEN) by FGFR2. pY240-PTEN is rapidly elevated and bound to chromatin through interaction with Ki-67 in response to IR treatment and facilitates the recruitment of RAD51 to promote DNA repair. Blocking Y240 phosphorylation confers radiation sensitivity to tumors and extends survival in GBM preclinical models. Y240F-Pten knock-in mice showed radiation sensitivity. These results suggest that FGFR-mediated pY240-PTEN is a key mechanism of radiation resistance and is an actionable target for improving radiotherapy efficacy.

Gastric Cancer (GC) is one of the most common and deadliest types of cancer in the world. To improve GC prognosis, increasing efforts are being made to develop new targeted therapies. Although FGFR2 genetic amplification and protein overexpression in GC have been targeted in clinical trials, so far no improvement in patient overall survival has been found. To address this issue, we studied genetic and epigenetic events affecting FGFR2 and its splicing regulator ESRP1 in GC that could be used as new therapeutic targets or predictive biomarkers. We performed copy number variation (CNV), DNA methylation, and RNA expression analyses of FGFR2/ESRP1 across several cohorts. We discovered that both genes were frequently amplified and demethylated in GC, resulting in increased ESRP1 expression and of a specific FGFR2 isoform: FGFR2-IIIb. We also showed that ESRP1 amplification in GC correlated with a significant decreased expression of FGFR2-IIIc, an alternative FGFR2 splicing isoform. Furthermore, when we performed a survival analysis, we observed that patients harboring diffuse-type tumors with low FGFR2-IIIc expression revealed a better overall survival than patients with FGFR2-IIIc high-expressing diffuse tumors. Our results encourage further studies on the role of ESRP1 in GC and support FGFR2-IIIc as a relevant biomarker in GC. Ipatimup integrate the i3S Research Unit, which is partially supported by FCT, the Portuguese Foundation for Science and Technology. This work was supported by: (1) FEDER?Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020?Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through Portuguese Science & Technology Foundation (FCT)/Minist?rio da Ci?ncia, Tecnologia e Inova??o in the framework of the project ?Institute for Research and Innovation in Health Sciences? (POCI-01-0145-FEDER-007274); (2) Project NORTE-01-0145-FEDER-000029 and NORTE-01-0145-FEDER-000003, supported by Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through FEDER; (3) FCT with the Grant References PTDC/BBB-ECT/2518/2014 and POCI-01-0145-FEDER-30164; (4) Project GenomePT Ref. POCI-01-0145-FEDER-022184, supported by COMPETE 2020?POCI, Lisboa Portugal Regional Operational Programme Lisboa2020, Algarve Portugal Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL 2020 Partnership Agreement, through FEDER and FCT; (5) FEDER-POCI-FCT Grant Ref. POCI-01-0145-FEDER-016390; (6) Salary support to M.F. by GenomePT Project ref POCI-01-0145-FEDER-022184; Fellowship to S.P.T. by Grant References PTDC/BBB-ECT/2518/2014. Funding: Ipatimup integrate the i3S Research Unit, which is partially supported by FCT, the Portuguese Foundation for Science and Technology. This work was supported by: (1) FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through Portuguese Science & Technology Foundation (FCT)/Ministério da Ciência, Tecnologia e Inovação in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274); (2) Project NORTE-01-0145-FEDER-000029 and NORTE-01-0145-FEDER-000003, supported by Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through FEDER; (3) FCT with the Grant References PTDC/BBB-ECT/2518/2014 and POCI-01-0145-FEDER-30164; (4) Project GenomePT Ref. POCI-01-0145-FEDER-022184, supported by COMPETE 2020—POCI, Lisboa Portugal Regional Operational Programme Lisboa2020, Algarve Portugal Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL 2020 Partnership Agreement, through FEDER and FCT; (5) FEDER-POCI-FCT Grant Ref. POCI-01-0145-FEDER-016390; (6) Salary support to M.F. by GenomePT Project ref POCI-01-0145-FEDER-022184; Fellowship to S.P.T. by Grant References PTDC/BBB-ECT/2518/2014.

Tight regulation of signaling from receptor tyrosine kinases is required for normal cellular functions and uncontrolled signaling can lead to cancer. Fibroblast growth factor receptor 2 (FGFR2) is a receptor tyrosine kinase that induces proliferation and migration. Deregulation of FGFR2 contributes to tumor progression and activating mutations in FGFR2 are found in several types of cancer. Here, we identified a negative feedback loop regulating FGFR2 signaling. FGFR2 stimulates the Ras/MAPK signaling pathway consisting of Ras-Raf-MEK1/2-ERK1/2. Inhibition of this pathway using a MEK1/2 inhibitor increased FGFR2 signaling. The putative ERK1/2 phosphorylation site at serine 780 (S780) in FGFR2 corresponds to serine 777 in FGFR1 which is directly phosphorylated by ERK1/2. Substitution of S780 in FGFR2 to an alanine also increased signaling. Truncated forms of FGFR2 lacking the C-terminal tail, including S780, have been identified in cancer and S780 has been found mutated to leucine in bladder cancer. Substituting S780 in FGFR2 with leucine increased FGFR2 signaling. Importantly, cells expressing these mutated versions of S780 migrated faster than cells expressing wild-type FGFR2. Thus, ERK1/2-mediated phosphorylation of S780 in FGFR2 constitutes a negative feedback loop and inactivation of this feedback loop in cancer cells causes hyperactivation of FGFR2 signaling, which may result in increased invasive properties.

Background Bone marrow stromal cells (BMSCs) are a heterogeneous population that participates in wound healing, immune modulation and tissue regeneration. Next generation sequencing was used to analyze transcripts from single BMSCs in order to better characterize BMSC subpopulations. Methods Cryopreserved passage 2 BMSCs from one healthy subject were cultured through passage 10. The transcriptomes of bulk BMSCs from designated passages were analyzed with microarrays and RNA sequencing (RNA-Seq). For some passages, single BMSCs were separated using microfluidics and their transcriptomes were analyzed by RNA-Seq. Results Transcriptome analysis by microarray and RNA-Seq of unseparated BMSCs from passages 2, 4, 6, 8, 9 and 10 yielded similar results; both data sets grouped passages 4 and 6 and passages 9 and 10 together and genes differentially expressed among these early and late passage BMSCs were similar. 3D Diffusion map visualization of single BMSCs from passages 3, 4, 6, 8 and 9 clustered passages 3 and 9 into two distinct groups, but there was considerable overlap for passages 4, 6 and 8 cells. Markers for early passage, FGFR2, and late passage BMSCs, PLAT, were able to identify three subpopulations within passage 3 BMSCs; one that expressed high levels of FGFR2 and low levels of PLAT; one that expressed low levels of FGFR2 and high levels of PLAT and one that expressed intermediate levels of FGFR2 and low levels of PLAT. Conclusions Single BMSCs can be separated by microfluidics and their transcriptome analyzed by next generation sequencing. Single cell analysis of early passage BMSCs identified a subpopulation of cells expressing high levels of FGFR2 that might include skeletal stem cells. Electronic supplementary material The online version of this article (10.1186/s12967-018-1766-2) contains supplementary material, which is available to authorized users.

Present study analyses the co-localisation of RIP5 with FGFR1, FGFR2 and HIP2 in the developing kidney, as RIP5 is a major determinant of urinary tract development, downstream of FGF-signaling.Paraffin embedded human kidney tissues of 16 conceptuses between the 6th-22th developmental week were analysed using double-immunofluorescence method with RIP5/FGFR1/FGFR2 and HIP2 markers. Quantification of positive cells were performed using Kruskal-Wallis test.In the 6th week of kidney development RIP5 (89.6%) and HIP2 (39.6%) are strongly expressed in the metanephric mesenchyme. FGFR1 shows moderate/strong expression in the developing nephrons (87.3%) and collecting ducts (70.5%) (p 0.05). RIP5/FGFR1 co-localized at the marginal zone and the ureteric bud with predominant FGFR1 expression. FGFR2 (26.1%) shows similar expression pattern as FGFR1 (70.5%) in the same kidney structures. RIP5/FGFR2 co-localized at the marginal zone and the collecting ducts (predominant expression of FGFR2). HIP2 is strongly expressed in collecting ducts (96.7%), and co-localized with RIP5. In 10th week, RIP5 expression decrease (74.2%), while the pattern of expression of RIP5 and FGFR1 in collecting ducts (33.4% and 91.9%) and developing nephrons (21.9% and 32.4%) (p 0.05) is similar to that in the 6th developmental week. Ureter is moderately expressing RIP5 while FGFR1 is strongly expressed in the ureteric wall. FGFR2 is strongly expressed in the collecting ducts (84.3%) and ureter. HIP2 have 81.1% positive cells in the collecting duct. RIP5/FGFR1 co-localize in collecting ducts and Henley's loop.The expression pattern of RIP5, FGFR1, FGFR2 and HIP2 in the human kidney development might indicate their important roles in metanephric development and ureteric muscle layer differentiation through FGF signaling pathways.

// Yunfei Xu 1, * , Xiaoqing Yang 2, * , Zhen Li 3 , Shuo Li 5 , Sen Guo 1 , Sayed Ismail 1 , Hongda Liu 1 , Zhihong Huang 4 , Zongli Zhang 1 , Yuxin Chen 1 , Qing Sun 2 1 Department of General Surgery, Qilu Hospital Affiliated to Shandong University, Jinan, Shandong, China 2 Department of Pathology, Qianfoshan Hospital Affiliated to Shandong University, Jinan, Shandong, China 3 Department of Neurology, Yidu Central Hospital of Weifang City, Weifang, Shandong, China 4 Department of Neurosurgery, Yidu Central Hospital of Weifang City, Weifang, Shandong, China 5 302 Hospital of People's Liberation Army, Beijing, China * These authors contributed equally to this work Correspondence to: Zongli Zhang, email: zzlzzl1900@163.com Yuxin Chen, email: cyxsdu2012@163.com Qing Sun, email: sunqqq2016@163.com , qingsw99@163.com Keywords: gastric adenocarcinoma, FGFR2, SPRY2, proliferation, invasion Received: December 26, 2015 Accepted: November 30, 2016 Published: December 16, 2016 ABSTRACT Fibroblast growth factor receptor 2 (FGFR2) has been identified as a predictive biomarker for unfavorable prognosis of gastric adenocarcinoma. As a well-defined antagonist in FGFR2-induced RAS/ERK activation, ectopic expression of sprouty (SPRY) family was reported in several kinds of cancers except gastric cancer. To explore the clinical significance of SPRY family and its correlation with FGFR2, we detected the expression of FGFR2 and SPRY family in 104 cases of gastric adenocarcinoma and subsequently analyzed their correlations with clinicopathological factors and overall survival rates by univariate and multivariate analysis. As the result, we demonstrated that both FGFR2 high-expression and SPRY2 low-expression indicated poorer prognosis of gastric adenocarcinoma. SPRY2 low-expression was significantly associated with FGFR2 high-expression, positive lymphatic invasion and metastasis. We further proved that SPRY2 could suppress FGFR2-induced ERK phosphorylation, cell proliferation and invasion with experiments in vitro and in vivo . In conclusion, we demonstrated that SPRY2 low-expression is a biomarker for unfavorable prognosis in gastric adenocarcinoma. SPRY2 can antagonize FGFR2-induced proliferation and invasion via suppressing ERK phosphorylation in gastric cancer cells, indicating SPRY2 as a potential therapeutic target for gastric adenocarcinoma treatment.

// Yafei Zhang 1 , Xianling Zeng 2 , Pengdi Liu 1 , Ruofeng Hong 1 , Hongwei Lu 1 , Hong Ji 1 , Le Lu 1 , Yiming Li 1 1 Department of General Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China 2 Department of Obstetrics and Gynecology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi’an, Shaanxi 710061, China Correspondence to: Yiming Li, email: liyimingdoc@163.com Keywords: breast cancer, FGFR2, polymorphism Received: August 08, 2016 Accepted: November 22, 2016 Published: December 09, 2016 ABSTRACT The association between fibroblast growth factor receptor 2 (FGFR2) polymorphism and breast cancer (BC) susceptibility remains inconclusive. The purpose of this systematic review was to evaluate the relationship between FGFR2 (rs2981582, rs2420946 and rs2981578) polymorphism and BC risk. PubMed, Web of science and the Cochrane Library databases were searched before October 11, 2015 to identify relevant studies. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the strength of associations. Sensitivity and subgroup analyses were conducted. Thirty-five studies published from 2007 to 2015 were included in this meta-analysis. The pooled results showed that there was significant association between all the 3 variants and BC risk in any genetic model. Subgroup analysis was performed on rs2981582 and rs2420946 by ethnicity and Source of controls, the effects remained in Asians, Caucasians, population-based and hospital-based groups. We did not carryout subgroup analysis on rs2981578 for the variant included only 3 articles. This meta-analysis of case-control studies provides strong evidence that FGFR2 (rs2981582, rs2420946 and rs2981578) polymorphisms were significantly associated with the BC risk. For rs2981582 and rs2420946, the association remained significant in Asians, Caucasians, general populations and hospital populations. However, further large scale multicenter epidemiological studies are warranted to confirm this finding and the molecular mechanism for the association need to be elucidated further.

Epileptogenic tumors affecting children and young adults are a morphologically diverse collection of neuroepithelial neoplasms that, as a group, exhibit varying levels of glial and/or neuronal differentiation. Recent advances in molecular profiling technology, including comprehensive DNA sequencing and methylation analysis, have enabled the application of more precise and biologically relevant classification schemes to these tumors. In this report, we describe a morphologically and molecularly distinct epileptogenic neoplasm, the polymorphous low-grade neuroepithelial tumor of the young (PLNTY), which likely accounts for a sizable portion of oligodendroglioma-like tumors affecting the pediatric population. Characteristic microscopic findings most notably include infiltrative growth, the invariable presence of oligodendroglioma-like cellular components, and intense immunolabeling for cluster of differentiation 34 (CD34). Moreover, integrative molecular profiling reveals a distinct DNA methylation signature for PLNTYs, along with frequent genetic abnormalities involving either B-Raf proto-oncogene (BRAF) or fibroblast growth factor receptors 2 and 3 (FGFR2, FGFR3). These findings suggest that PLNTY represents a distinct biological entity within the larger spectrum of pediatric, low-grade neuroepithelial tumors. Electronic supplementary material The online version of this article (doi:10.1007/s00401-016-1639-9) contains supplementary material, which is available to authorized users.

// Dominika Piasecka 1, 4 , Kamila Kitowska 1 , Dominika Czaplinska 2 , Kamil Mieczkowski 1 , Magdalena Mieszkowska 1 , Lukasz Turczyk 1 , Andrzej C. Skladanowski 1 , Anna J. Zaczek 2 , Wojciech Biernat 3 , Radzislaw Kordek 4 , Hanna M. Romanska 4 , Rafal Sadej 1 1 Department of Molecular Enzymology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Poland 2 Department of Cell Biology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Poland 3 Department of Pathomorphology, Medical University of Gdansk, Poland 4 Department of Pathology, Medical University of Lodz, Poland Correspondence to: Rafal Sadej, email: rsadej@gumed.edu.pl Hanna M. Romanska, email: hanna.romanska@gmail.com Keywords: progesterone receptor, FGFR2, breast cancer Received: April 12, 2016 Accepted: November 07, 2016 Published: November 12, 2016 ABSTRACT We have recently demonstrated that, fibroblast growth factor 2 (FGFR2), signalling via ribosomal S6 kinase 2 (RSK2), promotes progression of breast cancer (BCa). Loss of progesterone receptor (PR), whose activity in BCa cells can be stimulated by growth factor receptors (GFRs), is associated with poor patient outcome. Here we showed that FGF7/FGFR2 triggered phosphorylation of PR at Ser294, PR ubiquitination and subsequent receptor`s degradation via the 26S proteasome pathway in BCa cells. We further demonstrated that RSK2 mediated FGF7/FGFR2-induced PR downregulation. In addition, a strong synergistic effect of FGF7 and progesterone (Pg), reflected in the enhanced anchorage-independent growth and cell migration, was observed. Analysis of clinical material demonstrated that expression of PR inversely correlated with activated RSK (RSK-P) ( p = 0.016). Patients with RSK-P(+)/PR(–) tumours had 3.629-fold higher risk of recurrence ( p = 0.002), when compared with the rest of the cohort. Moreover, RSK-P(+)/PR(–) phenotype was shown as an independent prognostic factor ( p = 0.006). These results indicate that the FGF7/FGFR2-RSK2 axis promotes PR turnover and activity, which may sensitize BCa cells to stromal stimuli and contribute to the progression toward steroid hormone negative BCa.

// Seyoung Seo 1,* , Seong Joon Park 1,* , Min-Hee Ryu 1,* , Sook Ryun Park 1 , Baek-Yeol Ryoo 1 , Young Soo Park 2 , Young-Soon Na 3 , Chae-Won Lee 3 , Ju-Kyung Lee 3 and Yoon-Koo Kang 1 1 Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea 2 Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea 3 Asan Institute for Life Science, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea * Seyoung Seo, Seong Joon Park, Min-Hee Ryu have contributed equally to this study as first authors Correspondence to: Yoon-Koo Kang, email: // Keywords : FGFR2; amplification; advanced gastric cancer; prognosis; quantitative real-time polymerase chain reaction Received : July 20, 2016 Accepted : October 22, 2016 Published : October 27, 2016 Abstract Although Fibroblast growth factor receptor (FGFR) 2 gene amplification and its prognostic significance have been reported in resectable gastric cancers, information on these features remains limited in the metastatic setting. The presence of FGFR2 amplification was assessed in formalin-fixed, paraffin-embedded tissues using a quantitative PCR-based gene copy number assay with advanced gastric cancer cohorts. A total of 327 patients with tumor portion of ≥70% were analyzed for clinical features. Among these patients, 260 who received first-line fluoropyrimidine and platinum chemotherapy were analyzed for survival. Sixteen of 327 patients (4.9%) exhibited FGFR2 amplification. The amplification group showed associations with age

Mutations in Fibroblast Growth Factor Receptor II (FGFR2) have been identified in patients with Crouzon and Pfeiffer syndrome, among which rare mutations of the intracellular tyrosine kinase domain. Correlating subtle phenotypes with each rare mutation is still in progress. In Necker-Enfants Malades Hospital, we identified three patients harboring three different pathogenic variants of the same amino acid residue Asn-549 located in this domain: in addition to a very typical crouzonoid appearance, they all developed clinically relevant hydrocephalus, which is an inconstant feature of Crouzon and Pfeiffer syndrome. Overall, FGFR2 tyrosine kinase domain mutations account for 5/67 (7.4%) cases in our hospital. We describe a novel mutation, p.Asn549Ser, and new cases of p.Asn549His and p.Asn549Thr mutations, each reported once before. Our three cases of Asn-549 mutations, alongside with rare previously reported cases, show that these patients are at higher risk of hydrocephalus. Clinical and imaging follow-up, with possible early surgery, may help prevent secondary intellectual disability.

OncoTarget 7(44), 71429-71439 (2016). doi:10.18632/oncotarget.12198, Published by Impact Journals LLC, [S.l.]

We have previously demonstrated that fibroblast growth factor receptor 2 (FGFR2) activates ribosomal s6 kinase 2 (RSK2) in mammary epithelial cells and that this pathway promotes in vitro cell growth and migration. Potential clinical significance of FGFR2 and RSK2 association has never been investigated. Herein, we have undertaken an evaluation of a possible relationship between FGFR2/RSK2 interdependence and disease outcome in breast cancer (BCa) patients. The clinical analysis was complemented by an in vitro investigation of an involvement of RSK2 in the regulation of FGFR2 function. Primary tumour samples from 152 stage I–III BCa patients were examined for FGFR2 and RSK2 gene and protein expression. FGFR2 showed a positive correlation with RSK2 at both protein (p = 0.003) and messenger RNA (mRNA) (p = 0.001) levels. Lack of both FGFR2 and activated RSK (RSK-P) significantly correlated with better disease-free survival (DFS) (p = 0.01). Patients with tumours displaying immunoreactivity for either or both FGFR2 and RSK-P had 4.89-fold higher risk of recurrence when compared to the FGFR2/RSK-P-negative subgroup. FGFR2-RSK2 interactions were verified by co-immunoprecipitation and internalization assays in HB2 mammary epithelial cell line (characterized by high endogenous FGFR2 and RSK2 expression). In vitro analyses revealed that FGFR2 and RSK2 formed an indirect complex and that activated RSK exerted a significant impact on fibroblast growth factor 2 (FGF2)-triggered internalization of FGFR2. Our results suggest that the FGFR2-RSK2 signalling pathway is involved in pathophysiology of BCa and evaluation of FGFR2/RSK-P expression may be useful in disease prognostication. Electronic supplementary material The online version of this article (doi:10.1007/s13277-016-5266-9) contains supplementary material, which is available to authorized users.

Despite their suggested importance, the mechanistic roles of FGFR2 and gastric cancer stem cell (GCSC) marker CD44 remain unclear. We investigated cross talk between CD44 and FGFR2. FGFR2 and CD44 positively regulate each other's expression. While FGFR2 suppresses c-Myc transcription, CD44 activates it. c-Myc in turn augments FGFR2 transcription. CD44 knockdown (KD) depleted FGFR2 and other GCSC markers, decreased c-Myc and Sox2 expression, and suppressed tumor growth, whereas CD44 activation led to FGFR2 induction. FGFR2 KD decreased most GCSC marker expression, including CD44, but increased c-Myc and Sox2 expression and attenuated tumor growth. FGFR2 kinase inhibitor and FGFR2 neutralizing antibody decreased the CD44+/hi GCSC fraction. Conversely, FGFR2 overexpression increased CD44 and accelerated tumor growth in mice. FGFR2 was co-expressed and colocalized diffusively with CD44, EpCAM, and LGR5. In contrast, phospho-FGFR2 colocalized densely with CD44, forming an aggregated signaling complex that was prevented by FGFR2 inhibition. The c-Myc KD depleted FGFR2 but not CD44. Similarly to CD44+/hi phenotypes, sorted FGFR+/hi cells had larger volumes, formed more tumor spheres, grew faster in vivo with bigger tumor mass, and expressed more CD44, EpCAM, and HER2. These findings suggest that FGFR2+/hi cells have stemness properties. Moreover, in situ FGFR2 expression in patient-derived gastric cancer tissue correlated with tumorigenic potential in a xenograft model. In conclusion, CD44 and FGFR2 maintain stemness in gastric cancer by differentially regulating c-Myc transcription.

// Dawn Q. Chong 1,2 and Andrew X. Zhu 1 1 Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA 2 Division of Medical Oncology, National Cancer Centre Singapore, Singapore Correspondence to: Andrew X. Zhu, email: // Keywords : cholangiocarcinoma, genetics, IDH, FGFR2 Received : December 19, 2015 Accepted : April 10, 2016 Published : April 18, 2016 Abstract Cholangiocarcinoma (CCA) is a relatively rare malignancy that arises from the epithelial cells of the intrahepatic, perihilar and distal biliary tree. Intrahepatic CCA (ICC) represents the second most common primary liver cancer, after hepatocellular cancer. Two-thirds of the patients with ICC present with locally advanced or metastatic disease. Despite standard treatment with gemcitabine and cisplatin, prognosis remains dismal with a median survival of less than one year. Several biological plausibilities can account for its poor clinical outcomes. First, despite the advent of next generation and whole exome sequencing, no oncogenic addiction loops have been validated as clinically actionable targets. Second, the anatomical, pathological and molecular heterogeneity, and rarity of CCA confer an ongoing challenge of instituting adequately powered clinical trials. Last, most of the studies were not biomarker-driven, which may undermine the potential benefit of targeted therapy in distinct subpopulations carrying the unique molecular signature. Recent whole genome sequencing efforts have identified known mutations in genes such as epidermal growth factor receptor ( EGFR ), Kirsten rat sarcoma viral oncogene homolog ( KRAS ), v-raf murine sarcoma viral oncogene homolog ( BRAF ) and tumor protein p53 (TP53 ), novel mutations in isocitrate dehydrogenase ( IDH ), BRCA1-Associated Protein 1 ( BAP1 ) and AT-rich interactive domain-containing protein 1A ( ARID1A ), and novel fusions such as fibroblast growth factor receptor 2 ( FGFR2 ) and ROS proto-oncogene 1 ( ROS1 ). In this review, we will discuss the evolving genetic landscape of CCA, with an in depth focus on novel fusions (e.g. FGFR2 and ROS1 ) and somatic mutations (e.g. IDH1/2 ), which are promising actionable molecular targets.

// Ryuma Tokunaga 1, * , Yu Imamura 1, 2, * , Kenichi Nakamura 1 , Takatsugu Ishimoto 1 , Shigeki Nakagawa 1 , Keisuke Miyake 1 , Yu Nakaji 2, 3 , Yasuo Tsuda 2 , Masaaki Iwatsuki 1 , Yoshifumi Baba 1 , Yasuo Sakamoto 1 , Yuji Miyamoto 1 , Hiroshi Saeki 2 , Naoya Yoshida 1 , Eiji Oki 2 , Masayuki Watanabe 1, 2 , Yoshinao Oda 3 , Adam J. Bass 4, 5, 6 , Yoshihiko Maehara 2 , Hideo Baba 1 1 Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan 2 Department of Surgery and Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan 3 Department of Anatomic Pathology, Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan 4 Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA 5 Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA 6 Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA * These authors contributed equally to this work Correspondence to: Hideo Baba, e-mail: hdobaba@kumamoto-u.ac.jp Keywords: esophagogastric junction adenocarcinoma, esophageal adenocarcinoma, FGFR2, targeting therapy, amplification Received: November 02, 2015 Accepted: January 31, 2016 Published: February 27, 2016 ABSTRACT Background: Fibroblast growth factor receptor 2 (FGFR2) genetic alterations lead to tumor cell proliferation in various types of cancer. We hypothesized that FGFR2 amplification is associated with FGFR2 expression, resulting in tumor growth and poorer outcome in esophagogastric junction (EGJ) adenocarcinoma. Patients and Methods: A total of 176 consecutive chemo-naive patients with EGJ adenocarcinoma were enrolled from two academic institutions. FGFR2 amplification was examined by real-time PCR ( N = 140) and FGFR2 expression with immunohistochemical staining ( N = 176), and compared against clinicopathological factors and patient outcomes. The effects of FGFR2 inhibition or overexpression on cell proliferation, cell cycle, and apoptosis assays were investigated in EGJ adenocarcinoma cell lines. Downstream FGFR2, AKT and ERK were also examined. Results: Based on the correlation between FGFR2 levels and FGFR2 overexpression in vitro , FGFR2 amplification was defined as copy number > 3.0. In clinical samples, FGFR2 amplification and FGFR2 IHC expression were 15% and 61%, respectively. Although these two statuses were significantly correlated ( P < 0.05), only FGFR2 IHC expression was significantly associated with tumor depth (multivariate P < 0.001) and overall survival of patients (univariate P = 0.007). Supporting these findings, FGFR2 overexpression was associated with tumor cell proliferation, cell cycle progression, and anti-apoptosis. Selective inhibition of FGFR2 sufficiently suppressed tumor cell proliferation through de-phosphorylation of AKT and ERK. Conclusions: FGFR2 amplification was significantly associated with FGFR2 expression. FGFR2 expression (but not FGFR2 amplification) was associated with tumor growth and patient outcomes. Our findings support FGFR2 as a novel therapeutic target for EGJ adenocarcinoma.

PURPOSE To model keratoconus (KC) using induced pluripotent stem cells (iPSC) generated from fibroblasts of both KC and normal human corneal stroma by a viral method. METHODS Both normal and KC corneal fibroblasts from four human donors were reprogramed directly by delivering reprogramming factors in a single virus using 2A "self-cleaving" peptides, using a single polycistronic lentiviral vector coexpressing four transcription factors (Oct 4, Sox2, Klf4, and Myc) to yield iPSC. These iPS cells were characterized by immunofluorescence detection using of stem cell markers (SSEA4, Oct4, and Sox2). The mRNA sequencing was performed and the datasets were analyzed using ingenuity pathways analysis (IPA) software. RESULTS The generated stem cell-like clones expressed the pluripotency markers, SSEA4, Oct4, Sox2, Tra-1-60, and also expressed pax6. Our transcriptome analysis showed 4300 genes, which had 2-fold change and 870 genes with a q-value of

One diagnostic feature of craniosynostosis syndromes is mandibular dysgenesis. Using three mouse models of Apert, Crouzon and Pfeiffer craniosynostosis syndromes, we investigated how embryonic development of the mandible is affected by fibroblast growth factor receptor 2 (Fgfr2) mutations. Quantitative analysis of skeletal form at birth revealed differences in mandibular morphology between mice carrying Fgfr2 mutations and their littermates that do not carry the mutations. Murine embryos with the mutations associated with Apert syndrome in humans (Fgfr2+/S252W and Fgfr2+/P253R) showed an increase in the size of the osteogenic anlagen and Meckel's cartilage (MC). Changes in the microarchitecture and mineralization of the developing mandible were visualized using histological staining. The mechanism for mandibular dysgenesis in the Apert Fgfr2+/S252W mouse resulting in the most severe phenotypic effects was further analyzed in detail and found to occur to a lesser degree in the other craniosynostosis mouse models. Laser capture microdissection and RNA-seq analysis revealed transcriptomic changes in mandibular bone at embryonic day 16.5 (E16.5), highlighting increased expression of genes related to osteoclast differentiation and dysregulated genes active in bone mineralization. Increased osteoclastic activity was corroborated by TRAP assay and in situ hybridization of Csf1r and Itgb3. Upregulated expression of Enpp1 and Ank was validated in the mandible of Fgfr2+/S252W embryos, and found to result in elevated inorganic pyrophosphate concentration. Increased proliferation of osteoblasts in the mandible and chondrocytes forming MC was identified in Fgfr2+/S252W embryos at E12.5. These findings provide evidence that FGFR2 gain-of-function mutations differentially affect cartilage formation and intramembranous ossification of dermal bone, contributing to mandibular dysmorphogenesis in craniosynostosis syndromes. This article has an associated First Person interview with the joint first authors of the paper., Summary: FGFR2 gain-of-function mutations differentially affect cartilage formation and intramembranous ossification of dermal bone, resulting in abnormal embryonic osteogenesis of the mandible.

The association of the fibroblast growth factor receptor 2 gene (FGFR2) polymorphism rs2981582 with breast cancer has been extensively studied, whereas the role of this polymorphism in non-functioning pituitary adenoma (NFPA) has not been elucidated. We thus investigated a potential association of rs2981582 with NFPA. A total of 79 patients and 142 healthy control participants were enrolled in our study. DNA of the participants was extracted from peripheral blood samples and genotyped by using the MassARRAY method. We found that the AA genotype was associated with a higher risk of developing NFPA (OR = 1.743, 95%CI: 1.151–2.64, P=0.008). After adjusting for risk factors, significant difference was still observed between the two groups (OR = 1.862, 95%CI: 1.172–2.957, P=0.008). Moreover, under the assumptions of the recessive model (OR = 3.051, 95%CI: 1.403–6.635, P=0.005) and the additive model (AG: OR = 0.329, 95%CI: 0.144–0.755, P=0.009; AA: OR = 0.326, 95%CI: 0.141–0.757, P=0.009), rs2981582 was associated with an increased risk of NFPA. Our results proved that FGFR2 rs2981582 AA genotype was associated with a higher risk of NFPA. The recessive model and additive model also showed increased the risk of NFPA.

BACKGROUND/AIMS: Fibroblast growth factor receptor 2 (FGFR2) has attracted considerable interest as a therapeutic target in gastric cancer (GC). There is growing evidence to suggest that the bioavailability of the potent pro-tumor function of FGFR2 is associated with thrombospondins (TSPs). As a follow-on from our previous study, here we evaluated the potential clinical significance and mechanism of the relationship between FGFR2 and TSP4 in GC.METHODS: Expression levels of FGFR2 and TSP4 were detected by immunohistochemistry in GC tissue microarray slides. SGC7901 and MKN28 cell lines were used to confirm the relationship between FGFR2 and TSP4. In vitro cell viability, colony formation, and invasion and migration assays were performed to evaluate the effect of FGFR2-TSP4 axis on tumor cell activities. The mechanism of TSP4 regulated by FGFG2 was explored via small molecular inhibitors in vitro and a xenograft model.RESULTS: FGFR2 was shown to be markedly overexpressed in GC tissues and was correlated with a high risk of lymph node metastasis, late clinical stage, and poor prognosis. Low TSP4 expression was associated with shorter overall survival (OS) and advanced stage in GC patients. Interestingly, correlation analysis indicated that FGFR2 was negatively associated with TSP4. Indeed, in vitro and in vivo experiments suggested FGFR2 activation could downregulate TSP4 expression, which played an important role in the proliferation, invasion and migration of GC cells. We also found involvement of the PI3K-AKT-mTOR pathway in the FGFR2-TSP4 axis.CONCLUSION: The FGFR2 signal promotes human GC progression through the downregulation of TSP4 via PI3K-AKT-mTOR pathway. Our findings provide a foundation for further investigating promising therapeutic strategies for GC overexpressing FGFR2.

Whilst cross-talk between stroma and epithelium is critical for tissue development and homeostasis, aberrant paracrine stimulation can result in neoplastic transformation. Chronic stimulation of epithelial cells with paracrine Fibroblast Growth Factor 10 (FGF10) has been implicated in multiple cancers, including breast, prostate and pancreatic ductal adenocarcinoma. Here, we examine the mechanisms underlying FGF10-induced tumourigenesis and explore novel approaches to target FGF10 signaling in cancer.

Circular RNA UVRAG (circUVRAG), a type of non-coding RNA, is derived and cyclized by part of the exon from the UVRAG gene. However, the role of circUVRAG in bladder cancer (BLCA) has not been reported. The purpose of the present study was therefore to characterize the role of circUVRAG in BLCA. Bioinformatics analysis showed interactive relationships among circUVRAG, microRNA-223 (miR-223), and fibroblast growth factor receptor 2 (FGFR2). Quantitative real-time PCR was used to detect the expression of circUVRAG in BLCA cell lines. UM-UC-3 cells were stably transfected with siRNA against circUVRAG, and cell proliferation and migration ability were tested using the CCK8 assay, clone formation, and Transwell assays in vitro. Tumor xenograft formation and metastasis were determined using nude mice. Fluorescence in situ hybridization was used to confirm the subcellular localization of circUVRAG, and the luciferase reporter assay was used to confirm the relationships among circUVRAG, miR-223, and FGFR2. Results showed that circUVRAG was upregulated in BLCA cell lines. Downregulation of circUVRAG expression suppressed proliferation and metastasis both in vitro and in vivo. Downregulation of circUVRAG suppressed FGFR2 expression by "sponging" miR-223, which was confirmed by rescue experiments and luciferase reporter assay. Overall, the results showed that downregulation of circUVRAG suppressed the aggressive biological phenotype of BLCA. Taken together, silencing circular RNA UVRAG inhibited bladder cancer growth and metastasis by targeting the miR-223/FGFR2 axis, which may provide a potential biomarker and therapeutic target for the management of BLCA.

The human DEAD/H-box RNA helicase DDX6 (RCK/p54) is a protein encoded by the fusion gene from the t(11, 14)(q23, q32) chromosomal translocation observed in human B-cell lymphoma cell line RC-K8. DDX6 has a variety of functions such as translation initiation, pre-mRNA splicing, and ribosome assembly. However, details of the regulatory mechanism governing DDX6 and the functions of DDX6 are largely unknown. Previously, we reported that DDX6 is overexpressed in most malignant cell lines and clinical colorectal tumor samples and that DDX6 positively contributes to the pathogenesis of various cancers. In the current study, we aimed at revealing the function of DDX6 in HER2 and FGFR2 related human gastric cancer (GC) by using clinical samples and GC cell lines. DDX6 protein was overexpressed in about 60% of the clinical samples, HER2, in 35%, and FGFR2, in 30%, (n = 20). Interestingly, the DDX6 protein was overexpressed in all HER2-positive samples (n = 7), and in 83% (5 of 6) of the FGFR2-positive samples, which could reflect the contribution of DDX6 to the expression of HER2 and FGFR2. In the GC cell line MKN7, which has HER2 amplification, the knockdown of DDX6 by siR-DDX6 led to the decreased expression of the HER2 protein. On the other hand, the knockdown of HER2 did not influence the DDX6 expression. Similar results were also obtained for the KATO-III and HSC39 cell lines having amplified FGFR2 expression. The increased expression of DDX6 induced a significantly increased expression of the HER2 protein without increasing the mRNA expression. The results of an RNP Immunoprecipitation (RIP)-assay using GC cells indicated that the DDX6 protein acted as an RNA-binding protein for HER2 and FGFR2 mRNAs and positively regulated their post-transcriptional processes. These findings demonstrated that DDX6 was an upstream molecule that positively regulated the expression of HER2 and FGFR2 at the post-transcriptional step in GC cells.