Fibroblast Growth Factor Receptor Family Research Articles

Lenvatinib, a molecule with versatile application: from preclinical evidence to future development in anti-cancer treatment.

Lenvatinib is an emerging multi-kinase inhibitor with a preferential anti-angiogenic activity, which has shown efficacy in the treatment of renal cell carcinoma, differentiated thyroid cancer and hepatocellular carcinoma. It inhibits vascular endothelial growth factor receptor family (VEGFR1–3), fibroblast growth factor receptor family (FGFR1–4), platelet-derived growth factor receptor–alpha (PDGFRα), tyrosine-kinase receptor (KIT) and rearranged during transfection receptor (RET). In this review we have evaluated the development from bench to bedside of lenvatinib. PubMed, MEDLINE and clinicaltrials.gov are the sources of data. Furthermore, the preclinical in vitro and in vivo data, as well as efficacy and toxicity results of lenvatinib in the clinic, are presented and discussed. Treatment with lenvatinib causes side effects (hypertension, proteinuria, fatigue and diarrhea), which are predominantly related to the inhibition of angiogenesis. For these reasons, the identification of biomarkers of efficacy and resistance to lenvatinib is a key challenge in order to select responsive patients. This review provides an overview on lenvatinib's clinical use, perspectives and indications for future development.

The role of fibroblast growth factor signalling in Echinococcus multilocularis development and host-parasite interaction.

BackgroundAlveolar echinococcosis (AE) is a lethal zoonosis caused by the metacestode larva of the tapeworm Echinococcus multilocularis. The infection is characterized by tumour-like growth of the metacestode within the host liver, leading to extensive fibrosis and organ-failure. The molecular mechanisms of parasite organ tropism towards the liver and influences of liver cytokines and hormones on parasite development are little studied to date.Methodology/Principal findingsWe show that the E. multilocularis larval stage expresses three members of the fibroblast growth factor (FGF) receptor family with homology to human FGF receptors. Using the Xenopus expression system we demonstrate that all three Echinococcus FGF receptors are activated in response to human acidic and basic FGF, which are present in the liver. In all three cases, activation could be prevented by addition of the tyrosine kinase (TK) inhibitor BIBF 1120, which is used to treat human cancer. At physiological concentrations, acidic and basic FGF significantly stimulated the formation of metacestode vesicles from parasite stem cells in vitro and supported metacestode growth. Furthermore, the parasite’s mitogen activated protein kinase signalling system was stimulated upon addition of human FGF. The survival of metacestode vesicles and parasite stem cells were drastically affected in vitro in the presence of BIBF 1120.Conclusions/SignificanceOur data indicate that mammalian FGF, which is present in the liver and upregulated during fibrosis, supports the establishment of the Echinococcus metacestode during AE by acting on an evolutionarily conserved parasite FGF signalling system. These data are valuable for understanding molecular mechanisms of organ tropism and host-parasite interaction in AE. Furthermore, our data indicate that the parasite’s FGF signalling systems are promising targets for the development of novel drugs against AE.

Small Peptide Modulation of Fibroblast Growth Factor Receptor 3-Dependent Postnatal Lymphangiogenesis.

The fibroblast growth factor receptor (FGFR) family includes transmembrane receptors involved in a wide range of developmental and postdevelopmental biologic processes as well as a wide range of human diseases. In particular, FGFR3 has been implicated in the mechanism by which 9-cis retinoic acid (9-cisRA) induces lymphangiogenesis and improves lymphedema. The purpose of this study was to validate the efficacy of a novel small peptide FGFR3 inhibitor, peptide P3 (VSPPLTLGQLLS), and to elucidate the role of FGFR3 in 9-cisRA-induced lymphangiogenesis using this peptide. Peptide P3 effectively inhibited FGFR3 phosphorylation. In vitro, peptide P3-mediated FGFR3 inhibition did not decrease lymphatic endothelial cell (LEC) proliferation, migration, or tubule formation. However, peptide P3-mediated FGFR3 inhibition did block 9-cisRA-stimulated LEC proliferation, migration, and tubule formation. In vivo, peptide P3-mediated FGFR3 inhibition was sufficient to inhibit 9-cisRA-induced tracheal lymphangiogenesis. FGFR3 does not appear to be essential to nonpromoted LEC proliferation, migration, and tubule formation. However, FGFR3 may play a key role in LEC proliferation, migration, tubule formation, and postnatal in vivo lymphangiogenesis when pharmacologically induced by 9-cisRA. P3 may have the potential to be used as a precise regulatory control element for 9-cisRA-mediated lymphangiogenesis.

TAS-120 Cancer Target Binding: Defining Reactivity and Revealing the First Fibroblast Growth Factor Receptor 1 (FGFR1) Irreversible Structure.

1-[(3S)-3-[4-Amino-3-[2-(3,5-dimethoxyphenyl)ethynyl]-1H-pyrazolo[3,4-d]pyrimidin-1-yl]-1-pyrrolidinyl]-2-propen-1-one (TAS-120) is an irreversible inhibitor of the fibroblast growth factor receptor (FGFR) family, and is currently under phase I/II clinical trials in patients with confirmed advanced metastatic solid tumours harbouring FGFR aberrations. This inhibitor specifically targets the P-loop of the FGFR tyrosine kinase domain, forming a covalent adduct with a cysteine side chain of the protein. Our mass spectrometry experiments characterise an exceptionally fast chemical reaction in forming the covalent complex. The structural basis of this reactivity is revealed by a sequence of three X-ray crystal structures: a free ligand structure, a reversible FGFR1 structure, and the first reported irreversible FGFR1 adduct structure. We hypothesise that the most significant reactivity feature of TAS-120 is its inherent ability to undertake conformational sampling of the FGFR P-loop. In designing novel covalent FGFR inhibitors, such a phenomenon presents an attractive strategy requiring appropriate positioning of an acrylamide group similarly to that of TAS-120.

Targeting FGFR with BGJ398 in Breast Cancer: Effect on Tumor Growth and Metastasis.

Endocrine resistance and metastatic dissemination comprise major clinical challenges for breast cancer treatment. The fibroblast growth factor receptor family (FGFR) consists of four tyrosine kinase transmembrane receptors, involved in key biological processes. Genomic alterations in FGFR have been identified in advanced breast cancer and thus, FGFR are an attractive therapeutic target. However, the efficacy of FGFR inhibitors on in vivo tumor growth is still controversial. The purpose of this study was to evaluate the role of FGFR in tumor growth and breast cancer progression. Cell proliferation was assessed by 3H-thymidine uptake and cell counting in primary cultures of endocrine resistant mammary carcinomas and a human cell line, respectively. Tumor transplants and cell injections were used to determine in vivo growth and spontaneous metastasis. FGFR1-3 and αSMA expression were evaluated on primary tumors by immunohistochemistry. Antiprogestin resistant murine transplants and a human xenograft express high levels of total FGFR1-3. In vitro treatment with the FGFR inhibitor, BGJ398, impaired cell proliferation of resistant variants versus vehicle. In vivo, versus control, BGJ398 treatment decreased one out of four resistant tumors, however all tumors showed a decreased epithelial/stromal ratio. Finally, in a model of hormone resistant mammary cancer that spontaneously metastasizes to the lung, BGJ398 decreased the number of mice with lung metastasis. FGFR inhibitors are promising tools that require further investigation to identify sensitive tumors. These studies suggest that targeting FGFR combined with other targeted therapies will be useful to impair breast cancer progression.

Detection of Known and Novel FGFR Fusions in Non–Small Cell Lung Cancer by Comprehensive Genomic Profiling

IntroductionActivation of the fibroblast growth factor receptor (FGFR) family through fusion with various partners has been described in multiple cancer types, including NSCLC. FGFR inhibitors are currently being evaluated clinically for patients whose tumors harbor these fusions. MethodsHybrid capture–based comprehensive genomic profiling was performed on 26,054 consecutive formalin-fixed, paraffin-embedded specimens of NSCLC. ResultsFGFR fusions retaining the kinase domain were identified in 0.2% of NSCLC cases; they included 37 fibroblast growth factor receptor gene 3 (FGFR3)–transforming acidic coiled-coil containing protein 3 gene (TACC3) fusion–positive cases, two fibroblast growth factor receptor 2 (FGFR2)–shootin 1 gene (KIAA1598 [also known as SHTN1]) fusion–positive cases, one BCL2 associated athanogene 4 gene (BAG4)–fibroblast growth factor receptor 1 gene (FGFR1) fusion–positive case, and 12 novel FGFR1, FGFR2, FGFR3, and fibroblast growth factor receptor 4 gene (FGFR4) fusion–positive cases. Co-occurring EGFR or MNNG HOS Transforming gene (MET) alterations were observed in 8% of cases (four of 52), KRAS mutation was observed in three additional cases, and FGFR1 or FGFR3 amplification was observed in 10% of cases. The two patients with co-occurring EGFR mutations were previously treated with EGFR inhibitors. One patient with a novel FGFR2–leucine zipper transcription factor like 1 gene (LZTFL1) fusion had a partial response to the pan-FGFR inhibitor JNJ-42756493 and remained progression-free for 11 months. ConclusionFGFR fusions were detected by using comprehensive genomic profiling in 0.2% of NSCLCs; they occurred primarily in the absence of other known driver alterations, or in a subset of cases, as likely mechanisms of acquired resistance. One patient with a novel FGFR2 fusion had clinical benefit from an investigational FGFR inhibitor, suggesting that these alterations may predict response to targeted therapies.

Expression of FGF-2/FGFR-1 in normal mucosa, salivary gland, preneoplastic, and neoplastic lesions of the oral cavity.

Fibroblast growth factor 2 (FGF-2) is a multifunctional cytokine expressed in several tissues and involved in a wide variety of biologic activities, with one low molecular weight (LMW) protein present in the cytosol, which is secreted, acting via its receptors (FGFRs), and four high molecular weight (HMW) proteins located in the nucleus. Fibroblast growth factor receptor (FGFR) family has four (FGFR1-4) transmembrane tyrosine kinase receptors expressed on several cell types, and FGFR-1 has been indicated as a potential molecular target in several types of cancer, including oral squamous cell carcinoma (OSCC). The FGF-2/FGFR-1 expression has been studied in the oral cavity, and it was associated with the wound repair process, the development of benign and malignant salivary gland tumors, besides being related to oral potentially malignant disorders (OPMDs) and OSCC. Hence, we critically review the currently available data on FGF-2/FGFR-1 expression in the normal mucosa and lesions of the oral cavity.

Abstract A026: Expression of fibroblast growth factor receptor 1 isoforms and activation of different pathways in prostate cancer progression

Abstract Bone metastases typically develop in patients with advanced prostate cancer (PCa). Androgen deprivation is commonly used as treatment, but responses are short, and eventually the disease progresses to a castration-resistant form (CRPC). The fibroblast growth factor (FGF) axis is commonly altered during PCa progression. Our group and others have implicated the FGF axis in the pathogenesis of PCa progression in bone, identified it as a candidate target for therapy, and suggested that FGF receptor (FGFR)-1 mediates a positive feedback loop between PCa cells and bone cells. RNA sequencing studies of 183 human PCa samples indicated that the mean expression of FGFR-1 is the highest of all the FGFR family genes studied. Analyses of these FGFR-1 transcripts identified eight different protein-coding transcripts to be the most abundantly expressed with diverse human PCa tissue samples expressing different FGFR-1 isoforms. The overall goal of this project is to investigate implications of FGFR1/FGFR1 isoforms expression in the pathogenesis of PCa bone metastases. When we assessed the expression of the two best-characterized FGFR-1 isoforms (alpha (NM_023110.2) and beta (NM_023105.2), which represent the most abundant protein coding transcripts found in PCa, we observed that all patient-derived xenografts (PDXs) studied express significantly higher levels of FGFR-1 alpha than beta while PCa cell lines mostly express the beta isoform. Mining The Cancer Genome Atlas (TCGA) PCa data, we identified distinct patterns of gene expression associated with each FGFR-1 isoform (alpha and beta). Briefly, FGFR-1 beta (but not alpha) is significantly associated with pathways including the MAP-kinase signaling cascade, signaling by FGFR in disease and pathways in cancer. In vitro studies of FGF signaling activation in PCa cells expressing FGFR-1 isoforms alpha, beta or empty vector, confirmed these results. Male SCID mice injected intracardially with PC3-FGFR-1 alpha exhibited higher death rates compared to animals injected with either PC3-FGFR-1 beta or PC3-empty vector. Furthermore, higher number of metastases per mice as well as higher number of mice with bone metastases were observed in animals injected with PC3-FGFR-1 alpha. The fact that different prostate tumors express different FGFR-1 isoforms suggests that FGFR1 alpha and beta isoforms activate different genes or pathways in PCa cells and this may underlie, at least in part, PCa heterogeneity, pattern of progression, and differences in response to FGFR1 inhibitors. Further studies will warrant the understanding of the implications of FGFR-1 isoforms expression in the pathogenesis of PCa. Citation Format: Estefania Labanca, Jun Yang, Peter Shepherd, Justin Roberts, Michael Starbuck, Bradley Broom, Matthew Iyer, Christopher Logothetis, Arul Chinnaiyan, Nora Navone. Expression of fibroblast growth factor receptor 1 isoforms and activation of different pathways in prostate cancer progression [abstract]. In: Proceedings of the AACR Special Conference: Prostate Cancer: Advances in Basic, Translational, and Clinical Research; 2017 Dec 2-5; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(16 Suppl):Abstract nr A026.

Structural Alterations in Human Fibroblast Growth Factor Receptors in Carcinogenesis.

Fibroblast growth factor (FGF) plays an important role in human embryogenesis, angiogenesis, cell proliferation, and differentiation. Carcinogenesis is accompanied by aberrant constitutive activation of FGF receptors (FGFRs) resulting from missense mutation in the FGFR1-4 genes, generation of chimeric oncogenes, FGFR1-4 gene amplification, alternative splicing shift toward formation of mesenchymal FGFR isoforms, and FGFR overexpression. Altogether, these alterations contribute to auto- and paracrine stimulation of cancer cells and neoangiogenesis. Certain missense mutations are found at a high rate in urinary bladder cancer and can be used for non-invasive cancer recurrence diagnostics by analyzing urine cell pellet DNA. Chimeric FGFR1/3 and amplified FGFR1/2 genes can predict cell response to the targeted therapy in various oncological diseases. In recent years, high-throughput sequencing has been used to analyze exomes of virtually all human tumors, which allowed to construct phylogenetic trees of clonal cancer evolution with special emphasis on driver mutations in FGFR1-4 genes. At present, FGFR blockers, such as multi-kinase inhibitors, specific FGFR inhibitors, and FGF ligand traps are being tested in clinical trials. In this review, we discuss current data on the functioning of the FGFR family proteins in both normal and cancer cells, mutations in the FGFR1-4 genes, and mechanisms underlying their oncogenic potential, which might be interesting to a broad range of scientists searching for specific tumor markers and targeted anti-cancer drugs.

Placental surface area mediates the association between FGFR2 methylation in placenta and full-term low birth weight in girls

BackgroundFibroblast growth factor receptor 2 (FGFR2) gene encodes a protein of the fibroblast growth factor receptor family. FGFR2 gene expression is associated with the regulation of implantation process of placenta which plays a vital role in fetal growth. DNA methylation is widely known as a mechanism of fetal growth. However, it is unclear whether and how DNA methylation of FGFR2 gene in the placenta is associated with full-term low birth weight. This case-control study aims to explore the links between FGFR2 methylation in placenta and full-term low birth weight and to further examine the mediation effect of placental surface area on this association.ResultsWe conducted analyses for each of the five valid CpG sites at FGFR2 in 165 mother-baby pairs (86 FT-LBW vs. 79 FT-NBW) and found that per one standard deviation increase in the DNA methylation of CpG 11 at FGFR2 was associated with 1.64-fold higher risk of full-term low birth weight (OR = 1.64, 95% CI = [1.07, 2.52]) and 0.18 standard deviation decrease in placental surface area (β = − 0.18; standard error = 0.08, p = 0.02). The mediation effect of placental surface area on the association between DNA methylation and full-term low birth weight was significant in girls (OR = 1.38, 95% CI = [1.05, 1.80]) but not in boys. The estimated mediation proportion was 48.38%.ConclusionOur findings suggested that placental surface area mediated the association between DNA methylation of FGFR2 in placenta and full-term low birth weight in a sex-specific manner. Our study supported the importance of placental epigenetic changes in placental development and fetal growth.

Fibroblast growth factor receptor 1 and 3 expression is associated with regulatory PI3K/AKT kinase activity, as well as invasion and prognosis, in human laryngeal cancer.

Aberrant fibroblast growth factor receptor (FGFR) expression is thought to contribute to the development of many types of cancer. As yet, however, their impact on the course and prognosis of head and neck cancer remains to be determined. Here, we aimed to investigate the effects of expression of the FGFR family members FGFR1 and FGFR3, as well as their downstream PI3K/AKT signal-regulated kinases, on the aggressiveness and prognosis of laryngeal cancer. In total 137 surgically removed squamous cell laryngeal cancer (SCLC) and 100 matched non-cancerous laryngeal mucosa (NCLM) samples were assessed for mRNA expression using quantitative real-time PCR. The corresponding proteins were analyzed by Western blotting. SLUG expression was assessed by immunohistochemistry. The expression data were subsequently related to tumor front grading (TFG), local/nodal recurrences, prognosis and overall survival. The FGFR1, FGFR3 and PI3K/AKT kinase mRNA and protein levels were found to be significantly higher in the SCLC than the NCLM samples (p < 0.05). A high FGFR1 mRNA/protein expression level was found to be associated with an increased invasion rate, according to TFG scale and SLUG level, a high local/nodal recurrence rate and a poor prognosis (p < 0.05). Similarly, we found that a high FGFR3 mRNA/protein expression level was associated with a shorter survival time (p < 0.05). In addition, we found that high PI3K/AKT kinase mRNA/protein levels were associated with a high TFG (p < 0.05). We also found that FGFR1/3 mRNA and FGFR1 protein levels were inversely associated with overall survival (log-rank test: FGFR1 mRNA p = 0.03, FGFR3 mRNA p = 0.04, FGFR1 protein p = 0.03). Subsequent multivariate analyses revealed that high FGFR3 mRNA expression may serve as an independent poor prognostic factor (HR 2.32, 95% CI 1.03-6.59; p = 0.04). We also found that the p-PI3K regulatory kinase protein level was significantly associated with survival in the cohort studied (HR 1.78, 95% CI 0.64-8.53; p = 0.03). From our data we conclude that FGFR1 and FGFR3, as well as its downstream regulatory PI3K/AKT kinases, may serve as potential biomarkers for the invasiveness and prognosis of laryngeal cancer. The expression of FGFR1/3-PI3K/AKT regulatory pathway members may be instrumental for the identification of patients at risk for an unfavorable clinical outcome.

The Irreversible Covalent Fibroblast Growth Factor Receptor Inhibitor PRN1371 Exhibits Sustained Inhibition of FGFR after Drug Clearance.

An increasing number of cancers are known to harbor mutations, translocations, or amplifications in the fibroblast growth factor receptor (FGFR) family of kinases. The FGFR inhibitors evaluated in clinical trials to date have shown promise at treating these cancers. Here, we describe PRN1371, an irreversible covalent inhibitor of FGFR1-4 targeting a cysteine within the kinase active site. PRN1371 demonstrated strong FGFR potency and excellent kinome-wide selectivity in a number of biochemical and cellular assays, including in various cancer cell lines exhibiting FGFR alterations. Furthermore, PRN1371 maintained FGFR inhibition in vivo, not only when circulating drug levels were high but also after the drug had been cleared from circulation, indicating the possibility of sustained FGFR inhibition in the clinic without the need for continuous drug exposure. Durable tumor regression was also obtained in multiple tumor xenografts and patient-derived tumor xenograft models and was sustained even using an intermittent dosing strategy that provided drug holidays. PRN1371 is currently under clinical investigation for treatment of patients with solid tumors. Mol Cancer Ther; 16(12); 2668-76. ©2017 AACR.

Identification of an Indazole-Based Pharmacophore for the Inhibition of FGFR Kinases Using Fragment-Led de Novo Design.

Structure-based drug design (SBDD) has become a powerful tool utilized by medicinal chemists to rationally guide the drug discovery process. Herein, we describe the use of SPROUT, a de novo-based program, to identify an indazole-based pharmacophore for the inhibition of fibroblast growth factor receptor (FGFR) kinases, which are validated targets for cancer therapy. Hit identification using SPROUT yielded 6-phenylindole as a small fragment predicted to bind to FGFR1. With the aid of docking models, several modifications to the indole were made to optimize the fragment to an indazole-containing pharmacophore, leading to a library of compounds containing 23 derivatives. Biological evaluation revealed that these indazole-containing fragments inhibited FGFR1-3 in the range of 0.8-90 μM with excellent ligand efficiencies of 0.30-0.48. Some compounds exhibited moderate selectivity toward individual FGFRs, indicating that further optimization using SBDD may lead to potent and selective inhibitors of the FGFR family.

Syndromic Craniosynostosis Can Define New Candidate Genes for Suture Development or Result from the Non-specifc Effects of Pleiotropic Genes: Rasopathies and Chromatinopathies as Examples.

Craniosynostosis is a heterogeneous condition caused by the premature fusion of cranial sutures, occurring mostly as an isolated anomaly. Pathogenesis of non-syndromic forms of craniosynostosis is largely unknown. In about 15–30% of cases craniosynostosis occurs in association with other physical anomalies and it is referred to as syndromic craniosynostosis. Syndromic forms of craniosynostosis arise from mutations in genes belonging to the Fibroblast Growth Factor Receptor (FGFR) family and the interconnected molecular pathways in most cases. However it can occur in association with other gene variants and with a variety of chromosome abnormalities as well, usually in association with intellectual disability (ID) and additional physical anomalies. Evaluating the molecular properties of the genes undergoing intragenic mutations or copy number variations (CNVs) along with prevalence of craniosynostosis in different conditions and animal models if available, we made an attempt to define two distinct groups of unusual syndromic craniosynostosis, which can reflect direct effects of emerging new candidate genes with roles in suture homeostasis or a non-specific phenotypic manifestation of pleiotropic genes, respectively. RASopathies and 9p23p22.3 deletions are reviewed as examples of conditions in the first group. In particular, we found that craniosynostosis is a relatively common component manifestation of cardio-facio-cutaneous (CFC) syndrome. Chromatinopathies and neurocristopathies are presented as examples of conditions in the second group. We observed that craniosynostosis is uncommon on average in these conditions. It was randomly associated with Kabuki, Koolen-de Vries/KANSL1 haploinsufficiency and Mowat–Wilson syndromes and in KAT6B-related disorders. As an exception, trigonocephaly in Bohring-Opitz syndrome reflects specific molecular properties of the chromatin modifier ASXL1 gene. Surveillance for craniosynostosis in syndromic forms of intellectual disability, as well as ascertainment of genomic CNVs by array-CGH in apparently non-syndromic craniosynostosis is recommended, to allow for improvement of both the clinical outcome of patients and the accurate individual diagnosis.

FGFR inhibitor, AZD4547, impedes the stemness of mammary epithelial cells in the premalignant tissues of MMTV-ErbB2 transgenic mice

The fibroblast growth factor receptor (FGFR) family of receptor tyrosine kinases (RTKs) regulates signaling pathways involved in cell proliferation and differentiation. Currently, the anti-tumor properties of FGFR inhibitors are being tested in preclinical and clinical studies. Nevertheless, reports on FGFR inhibitor-mediated breast cancer prevention are sparse. In this study, we investigated the anti-cancer benefits of AZD4547, an FGFR1-3 inhibitor, in ErbB2-overexpressing breast cancer models. AZD4547 (1–5 µM) demonstrated potent anti-proliferative effects, inhibition of stemness, and suppression of FGFR/RTK signaling in ErbB2-overexpressing human breast cancer cells. To study the in vivo effects of AZD4547 on mammary development, mammary epithelial cell (MEC) populations, and oncogenic signaling, MMTV-ErbB2 transgenic mice were administered AZD4547 (2–6 mg/kg/day) for 10 weeks during the ‘risk window’ for mammary tumor development. AZD4547 significantly inhibited ductal branching and MEC proliferation in vivo, which corroborated the in vitro anti-proliferative properties. AZD4547 also depleted CD24/CD49f-sorted MEC populations, as well as the CD61highCD49fhigh tumor-initiating cell-enriched population. Importantly, AZD4547 impaired stem cell-like characteristics in primary MECs and spontaneous tumor cells. Moreover, AZD4547 downregulated RTK, mTOR, and Wnt/β-catenin signaling pathways in premalignant mammary tissues. Collectively, our data provide critical preclinical evidence for AZD4547 as a potential breast cancer preventative and therapeutic agent.

A de novo missense mutation of FGFR2 causes facial dysplasia syndrome in Holstein cattle

BackgroundSurveillance for bovine genetic diseases in Denmark identified a hitherto unreported congenital syndrome occurring among progeny of a Holstein sire used for artificial breeding. A genetic aetiology due to a dominant inheritance with incomplete penetrance or a mosaic germline mutation was suspected as all recorded cases were progeny of the same sire. Detailed investigations were performed to characterize the syndrome and to reveal its cause.ResultsSeven malformed calves were submitted examination. All cases shared a common morphology with the most striking lesions being severe facial dysplasia and complete prolapse of the eyes. Consequently the syndrome was named facial dysplasia syndrome (FDS). Furthermore, extensive brain malformations, including microencephaly, hydrocephalus, lobation of the cerebral hemispheres and compression of the brain were present. Subsequent data analysis of progeny of the sire revealed that around 0.5% of his offspring suffered from FDS.High density single nucleotide polymorphism (SNP) genotyping data of the seven cases and their parents were used to map the defect in the bovine genome. Significant genetic linkage was obtained for three regions, including chromosome 26 where whole genome sequencing of a case-parent trio revealed two de novo variants perfectly associated with the disease: an intronic SNP in the DMBT1 gene and a single non-synonymous variant in the FGFR2 gene. This FGFR2 missense variant (c.927G>T) affects a gene encoding a member of the fibroblast growth factor receptor family, where amino acid sequence is highly conserved between members and across species. It is predicted to change an evolutionary conserved tryptophan into a cysteine residue (p.Trp309Cys). Both variant alleles were proven to result from de novo mutation events in the germline of the sire.ConclusionsFDS is a novel genetic disorder of Holstein cattle. Mutations in the human FGFR2 gene are associated with various dominant inherited craniofacial dysostosis syndromes. Given the phenotypic similarities in FDS affected calves, the genetic mapping and absence of further high impact variants in the critical genome regions, it is highly likely that the missense mutation in the FGFR2 gene caused the FDS phenotype in a dominant mode of inheritance.

Abstract 1824: Endothelial mTORC2 deficiency inhibits tumor angiogenesis, tumor progression and metastasis in non-small cell lung cancer (NSCLC)

Abstract Vascular endothelial cells (ECs) are specialized components of the tumor microenvironment that orchestrates tumor growth and invasion. They form tumor-associated blood vessels (angiogenic) that supply nutrients and oxygen, remove waste products, and also provide an entry site for tumorigenic cells to spread to secondary sites in various organs. One of the major signaling events in tumor vessels is PI3K/PDK-AKT-mTOR activation. mTOR is a serine/threonine kinase that functions in two distinct complexes, mTORC1 and mTORC2,which regulate a diverse array of cellular processes including cell growth, survival and metabolism. Although mTORC1, and to lesser extent, mTORC2, has been broadly studied in cancers and diseases, little is known regarding the relative contributions of mTORC1 versus mTORC2 in tumor endothelium. Using mouse model of endothelium-specific Rictor (a mTORC2 specific cofactor) gene targeting, we discovered that endothelial Rictor deletion decreased tumor neovascularization, suppressed tumor growth, and prevented metastasis in vivo. Direct co-culture of endothelial cells and NSCLC tumor cells in vitro showed that knockdown of endothelial Rictor inhibited tumor cell proliferation while Raptor (a mTORC1 specific cofactor) depletion had a modest effect. However, loss of endothelial Rictor or Raptor both markedly decreased tumor cell extravasation in response to endothelial cells, and also inhibited tumor spheroid formation in a direct co-culture system. Furthermore, a screen of phospho-kinase arrays revealed that Raptor or Rictor depletion in endothelial cells decreased various phosphor-RTKs in tumor cells that were co-cultured with ECs, including members of the Eph receptor family, Insulin receptor family and FGF receptor family. Additionally, endothelial Rictor knockdown suppressed phosphorylation levels of nerve growth factor receptors TrkB and TrkC in tumor cells. Collectively, these data suggest that endothelial mTORC1 and mTORC2 play critical roles in regulating tumor progression through distinct signaling pathways. Note: This abstract was not presented at the meeting. Citation Format: Shan Wang. Endothelial mTORC2 deficiency inhibits tumor angiogenesis, tumor progression and metastasis in non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1824. doi:10.1158/1538-7445.AM2017-1824

Abstract 2095: E7090, a novel and selective FGFR inhibitor, for the treatment of cholangiocarcinoma cells harboring FGFR2-fusion genes

Abstract Genetic abnormalities (gene fusion, mutation and amplification) of fibroblast growth factor receptor (FGFR) family members are known to cause constitutive activation of their signaling pathways, which play an important role in proliferation, survival and migration of cancer cells, as well as tumor angiogenesis. Several recent studies have identified that FGFR2 gene fusions were found in about 10% of intrahepatic cholangiocarcinoma and acted as oncogenes. E7090, an orally available FGFR1, 2 and 3 inhibitor, whose chemical-structure and basic kinase inhibitory profile have been disclosed at AACR2015, is currently under a first-in-human study (NCT02275910). The antitumor activity of E7090 against NIH3T3 and human cholangiocarcinoma cells harboring FGFR2-fusion genes was investigated. NIH3T3 cells stably infected of five FGFR2-fusion genes (FGFR2-AHCYL1, FGFR2-BICC1 type1, FGFR2-BICC1 type2, FGFR2-TXLNA, or FGFR2-KCTD1), all of which were discovered in human intrahepatic cholangiocarcinoma patients, were successfully established and exhibited anchorage-independent cell growth in soft agar assay. E7090 revealed an inhibitory activity on soft agar colony formation of these cells with IC50 values of 0.9 to 17.3 nmol/L in a dose dependent manner. E7090 also reduced activation of downstream pathways of FGFR signaling (MAPK and STAT3) in these cells. Subcutaneous transplantation of FGFR2-BICC1 type2, FGFR2-TXLNA, or FGFR2-KCTD1 expressing cells into immune-deficient mice produced tumor growth, and then oral administration of E7090 at 12.5, 25 and 50 mg/kg showed significant tumor growth inhibition. Finally, antitumor activity of E7090 was examined in a patient derived xenograft (PDX) model of human cholangiocarcinoma harboring FGFR2-BICC1 fusion gene. E7090 also showed dose-dependent antitumor activity and more than 50% of tumor regression was achieved at a dose of 50 mg/kg. In conclusion, E7090 showed potent antitumor activity against FGFR2-fusion genes found in intrahepatic cholangiocarcinoma both in vitro and in vivo models, suggesting that E7090 may provide therapeutic opportunities for cholangiocarcinoma harboring FGFR2-fusion genes. Citation Format: Saori W. Miyano, Yasuhito Arai, Junji Matsui, Tatsuhiro Shibata. E7090, a novel and selective FGFR inhibitor, for the treatment of cholangiocarcinoma cells harboring FGFR2-fusion genes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2095. doi:10.1158/1538-7445.AM2017-2095

Abstract 1908: FGFR inhibitor, AZD4547, impedes the stemness of mammary epithelial cells in the premalignant tissues of MMTV-ErbB2 transgenic mice

Abstract The fibroblast growth factor receptor (FGFR) family (FGFR1-4) of receptor tyrosine kinases (RTKs) regulates signaling pathways involved in cell proliferation and differentiation. In particular, FGFR1 and FGFR2, which are found in the terminal end buds of developing mammary ducts, play a role in mammary development and glandular morphogenesis involving the regulation of mammary stem cells (MaSCs) in mice. As such, a number of FGFR inhibitors are being tested in preclinical studies and clinical trials for anti-tumor properties. Nevertheless, reports on FGFR inhibitor-mediated breast cancer prevention are sparse. In this study, we aimed to investigate the anti-cancer benefits of AZD4547, a small molecule inhibitor of FGFR1-3, on ErbB2-overexpressing breast cancer models. We particularly focus on the effects of AZD4547 on MaSCs and tumor-initiating cells (TICs) in the premalignant tissues of MMTV-ErbB2 transgenic mice. We first demonstrated the anti-proliferative effects of AZD4547 (1-5 µM) on human ErbB2-overexpressing breast cancer cell lines. We further showed that AZD4547 confers potent inhibition of the stemness of these breast cancer cells, as indicated by significant depletion of ALDH+ cells and impaired tumorsphere formation. To study the in vivo effects of AZD4547 on the stemness of mammary epithelial cells (MECs), MMTV-ErbB2 transgenic mice were administered AZD4547 (2-6 mg/kg/day) for 10 weeks (weeks 8-18 of age) during the ‘risk window’ for mammary tumor development. Histopathological analysis indicated that AZD4547 significantly inhibited ductal branching and MEC proliferation. To examine the effect of AZD4547 on MEC subpopulations and tissue hierarchy dynamics in the premalignant mammary tissues of this model, we performed flow cytometry analyses on the primary MECs using CD24/CD49f and CD61/CD49f cell surface markers. The results showed that AZD4547 treatment substantially reduced MaSC-derived luminal and myoepithelial cell populations. AZD4547 also selectively suppressed the CD61highCD49fhigh cell population, which is enriched with luminal progenitor cells that give rise to TICs during MMTV-ErbB2 mammary tumor development. Mammosphere and colony-forming cell (CFC) assays on primary MECs demonstrated that the stemness of these cells was also blocked by AZD4547 prior to malignant transformation. Consistently, AZD4547 inhibited the anchorage-independent growth of cells from spontaneous tumors. Moreover, we demonstrated that AZD4547 downregulated multiple pathways, including the inactivation of FGFR, EGFR, and Wnt/β-catenin signaling. Collectively, the morphogenic, MaSC/TIC, and signaling regulation associated with AZD4547 treatment provides critical evidence for AZD4547 as a breast cancer preventative and therapeutic agent, which ultimately reveals clues for more effective eradication of refractory mammary tumors. Citation Format: Qingxia Zhao, Amanda B. Parris, Erin W. Howard, Ming Zhao, Ying Xing, Zhikun Ma, Xiaohe Yang. FGFR inhibitor, AZD4547, impedes the stemness of mammary epithelial cells in the premalignant tissues of MMTV-ErbB2 transgenic mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1908. doi:10.1158/1538-7445.AM2017-1908

Abstract 5730: Increased FGFRL1 expression is associated with prostate cancer progression

Abstract Prostate cancer (PCa) is the most diagnosed cancer in men in developed countries. Fibroblast growth factor receptors (FGFRs) have been demonstrated to play an important role in PCa initiation and progression. Fibroblast growth factor receptor like 1 (FGFRL1) is the most recently identified member of the FGFR family. Its extracellular domain shares high similarity to FGFR1-4 but it lacks the cytoplasmic domain with tyrosine kinase activity. Thus, FGFRL1 is able to bind FGF ligands but the subsequent intracellular signaling cascade is defective. We observed up-regulation of FGFRL1 mRNA expression in PCa in a public genome-wide cancer transcriptome data base (cBioPortal). To validate the expression data and to investigate the putative role of upregulated FGFRL1 protein in normal prostate and PCa, tissue microarrays containing different types of benign and malignant prostate tissue were used. Altered FGFRL1 protein expression was correlated with clinical parameters; and both in vitro and in vivo experiments were applied to study the biological functions FGFRL1 in PCa cell lines. Our results confirmed that FGFRL1 expression is upregulated in PCa compared to normal prostate. More specifically, increased cytoplasmic and nuclear FGFRL1 expression was associated with high Gleason score and Ki67 expression, while membrane-associated FGFRL1 showed the opposite correlation. To investigate the effects of androgens on FGFRL1 in vitro, PCa cells were treated with dihydrotestosterone and/or MDV3100, an androgen receptor inhibitor. Dihydrotestosterone increased FGFRL1 expression and MDV3100 inhibited endogenous FGFRL1 expression, but not when stimulated by dihydrotestosterone, suggesting indirect androgen-mediated regulation. The in vitro studies also showed that FGFRL1 is able to attenuate the phosphorylation of FRS2α and ERK1/2 by FGF ligands, providing evidence for the assumed decoy function of membranous FGFRL1. However, knock-down of FGFRL1 in PC3M cells resulted in reduced cell growth in tumor xenografts. Additionally, mRNA sequencing on PC3M cells with FGFRL1 knock-down revealed differential expression of about 250 molecules, including several metalloproteinases and FGFR1, compared to control cells (FDR&amp;lt;0.1 and -1&amp;gt;logFC&amp;gt;1). In conclusion, we suggest that upregulation and altered subcellular localization of FGFRL1, in PCa, directly or indirectly, promotes tumor growth and progression. The results suggest that FGFRL1 is a potent regulator of gene expression and may be involved in diverse functions depending on its cellular localization. Citation Format: Lan Yu, Mervi Toriseva, Andrew Erickson, Heikki Seikkula, Martti Nurmi, Pekka Taimen, Peter Boström, Tuomas Mirtti, Kalle Alanen, Markku Kallajoki, Johanna Tuomela, Mattias Nees, Pirkko Härkönen. Increased FGFRL1 expression is associated with prostate cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5730. doi:10.1158/1538-7445.AM2017-5730