Mutations In Fibroblast Growth Factor Receptor Research Articles

Predictive biomarkers in bladder cancer

In the last few years, significant progress has been achieved in the therapeutic options for advanced urothelial bladder cancer. The aim of this work was to give an overview of the status and future perspective of the therapeutic options in this setting. Its focus is on the discussion of tissue-based therapy-predictive markers, which are evaluated through (molecular) pathology and thereby strengthening the role of pathology itself. Current (clinical study) data, the literature, and our own expertise were considered and summarized in the areas of therapy prediction of platinum-based chemotherapy, immunotherapy, and other therapeutic approaches. Molecular subtypes exhibit apredictive value both in platinum-based chemotherapy as well as in immunotherapy. However, further work is required to elucidate the predictive role of molecular subtypes in both settings. Changes in the DNA damage repair enzyme (DDR) genes, ERCC2, and ERBB2 as well as differences in the expression of EMMPRIN, survivin, and HMGA2 show promising results as further markers of chemotherapy efficacy. In the prediction of immunotherapy success, this mainly relates to the evaluation of the tumor mutation burden (TMB), tumor neoantigen burden (TNB), APOBEC signatures (MSig1; 3A/3B), and CD8-positive T‑effector cell signature. When using the fibroblast growth factor receptor (FGFR) inhibitor erdafitinib, which has not yet been approved in Germany, the evaluation of specific FGFR mutations and/or gene fusions by acompanion diagnostic test is mandatory in the USA.

In�vitro antitumor effects of FGFR and PI3K inhibitors on human papillomavirus positive and negative tonsillar and base of tongue cancer cell lines

Human papillomavirus positive (HPV+) tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC) have better outcomes than corresponding HPV- negative (HPV-) cancer cases. Our previous study demonstrated that fibroblast growth factor receptor 3 (FGFR3) and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit a (PIK3CA) are often mutated in HPV+ cancer. To investigate whether targeted therapy is an option for TSCC/BOTSCC, two HPV+ and one HPV- TSCC/BOTSCC cell lines were tested for their sensitivity towards FGFR and PI3K inhibitors. The HPV+ cell lines UM-SCC-47 and UPCI-SCC-154, and the HPV- cell line UT-SSC-60A were tested by competitive allele-specific TaqMan-PCR for presence/absence of frequently occurring FGFR3 and PIK3CA mutations. All cells were then treated with FGFR inhibitor AZD4547 and PI3K inhibitors BEZ235 and BKM120 alone, or with AZD4547 and BEZ235 in combination. Viability was analyzed using a WST-1 assay, cytotoxicity tested by a CellTox Green cytotoxicity assay, apoptosis analyzed by a Caspase Glo 3/7 assay and proliferation examined with the xCELLigence system. HPV+ UM-SCC-47 and UPCI-SCC-154 cells, and HPV- UT-SSC-60A cells, did not exhibit any common FGFR3 or PIK3CA mutations, but were all sensitive to FGFR inhibitor AZD4547 and PI3K inhibitors BEZ235 and BKM120. Notably, HPV+ UPCI-SCC-154 cells were more sensitive than the other two cell lines. Furthermore, when AZD4547 and BEZ235 treatment was combined in HPV+ UPCI-SCC-154 and HPV- UT-SSC-60A cells, potentiated combination effects were observed. HPV+ UM-SCC-47 and UPCI-SCC-154 cells, and HPV- UT-SSC-60A cells had no common FGFR3 or PIK3CA mutations, but were sensitive to FGFR inhibitor AZD4547, and PI3K inhibitors BEZ235 and BKM120. Furthermore, the latter two cell lines were particularly sensitive to combinations of AZD4547 and BEZ235.

Analyses of FGFR3 and PIK3CA mutations in neuroblastomas and the effects of the corresponding inhibitors on neuroblastoma cell lines.

Fibroblast growth factor receptor (FGFR)3 and phosphatidylinositol‑4,5‑bisphosphate 3‑kinase, catalytic subunit alpha (PIK3CA) mutations are found in various types of cancer, such as urinary bladder cancer, human papillomavirus‑positive tonsillar and base of the tongue squamous cell carcinoma, breast cancer and some childhood sarcomas. Several drugs can target these genes, some of which have been used for the treatment of urinary bladder cancer. Much less is known about childhood cancer. For this reason, the present study investigated the presence of such mutations in neuroblastomas (NBs) and tested NB cell lines for sensitivity to FGFR and phosphoinositide 3‑kinase (PI3K) inhibitors. In total, 29NBs were examined for the presence of the three most common FGFR3 and PIK3CA mutations using a competitive allele‑specific TaqMan PCR (CAST‑PCR). Furthermore, the SK‑N‑AS, SK‑N‑BE(2)‑C, SK‑N‑DZ, SK‑N‑FI and SK‑N‑SH NB cell lines (where SK‑N‑DZ had a deletion of PIK3C2G, none had FGFR mutations according to the Cancer Program's Dependency Map, but some were chemoresistant), were tested for sensitivity to FGFR (AZD4547) and PI3K (BEZ235 and BKM120) inhibitors by viability, cytotoxicity, apoptosis and proliferation assays. CAST‑PCR detected one FGFR3 mutation in 1/29NBs. Following treatment with FGFR and PI3K inhibitors, a decrease in viability and proliferation was observed in the majority, but not all, the cell lines. Following combination treatment with both drugs, the sensitivity of all cell lines was increased. On the whole, the findings of this study demonstrate that FGFR3 and PIK3CA mutations are uncommon in patients with NB. However, certain NB cell lines are rather sensitive to both FGFR and PI3K inhibitors alone, and even more so when the different drugs are used in combination.

1988P - Identification of novel and known FGFR gene fusions in Chinese non-small cell lung cancer

BackgroundOncogenic fibroblast growth factor receptor (FGFR) gene fusions have been described in diverse tumor histology. FGFR inhibitors including erdafitinib have demonstrated promising results in patients whose tumors harbor FGFR gene fusions or mutations. We hereby assessed the frequency of FGFR rearrangements in the Chinese non-small cell lung cancer (NSCLC) population. MethodsA total of 10,966 NSCLC patients whose tumor specimen and/or circulating cell-free DNA (cfDNA) submitted for genomic profiling by hybridization capture-based targeted next-generation sequencing (NGS) of exons and introns of cancer related genes were retrospectively reviewed. Patients’ clinical characteristics and treatment history were retrieved from the database for further evaluation. ResultsFGFR fusions retaining the intact kinase domain were identified in 0.11% (12/10966) of NSCLC cases examined, including 9 fibroblast growth factor receptor 3 (FGFR3)-transforming acidic coiled-coil containing protein 3 gene (TACC3) fusion-positive cases that was mostly reported in solid tumors, one fibroblast growth factor receptor 2 (FGFR2)-internexin neuronal intermediate filament protein α gene (INA) fusion that was previously reported in gliomas, one novel fibroblast growth factor receptor 4 (FGFR4)-Rap guanine nucleotide exchange factor like 1 gene (RAPGEFL1) fusion case, and one novel fibroblast growth factor receptor 1 (FGFR1) gene fusion involving the 5’UTR of Solute Carrier Family 20 Member 2 gene (SLC20A2) which may possibly drive the overexpression of FGFR1. Concomitant EGFR mutations or EGFR amplification were observed in 6 patients, four of which were previously treated with EGFR tyrosine kinase inhibitors (TKIs), but disease progressed prior to NGS tests. FGFR fusions may arise as resistance mechanism to EGFR TKI therapies in patients who carried founder EGFR alterations. No other known concurrent driver mutations were detected in the remaining 6 cases. ConclusionsWe hereby report a frequency of FGFR fusions of 0.11% in a large Chinses NSCLC population involving known and novel FGFR gene fusion partners including TACC3, INA, RAPGEFL1, and SLC20A2. Oncogenic FGFR fusions may arise as mechanisms of acquired resistance. Legal entity responsible for the studyGeneseeq Technology Inc. FundingHas not received any funding. DisclosureQ. Ou: Full / Part-time employment, NA: Geneseeq Technology Inc. X. Wu: Leadership role, NA: Geneseeq Technology Inc. X. Wang: Full / Part-time employment, NA: Nanjing Geneseeq Technology Inc. Y.W. Shao: Leadership role, NA: Geneseeq Technology Inc. All other authors have declared no conflicts of interest.

141P - A comprehensive pan-cancer study of FGFR aberrations in Chinese cancer patients

BackgroundAberrations in fibroblast growth factor receptors (FGFR) are common in multiple cancers, making them highly promising therapeutic targets. Optimal application of FGFR inhibitors requires a comprehensive understanding of the prevalence and types of FGFR mutations, which may vary significantly among ethnicities. Such analysis has not been conducted in Chinese pan-cancer. This study investigated the prevalence and the distribution of FGFR aberrations in Chinese cancer patients. MethodsWe screened genomic profiling results of plasma or tissue samples from 10,582 patients spanning 16 cancer types: lung, breast, gastric, hepatobiliary, pancreatic, soft tissue sarcoma, esophageal, ovarian, colorectal, head and neck, renal, endometrial, osteogenic sarcoma, cervical, melanoma and lymphoma. ResultsOf the 10,582 patients screened, we observed 745 patients with FGFR aberrations, revealing an overall prevalence of 7.03%. Approximately, 3.78% harbored FGFR amplification, 2.73% had other mutations and 0.53% had fusions. A majority (56.78%) of patients had FGFR1 aberrations, followed by 17.72%, 14.43% and 2.82% with FGFR3, FGFR2 and FGFR4 aberrations, respectively. Furthermore, 8.46% of patients with aberrations in more than 1 FGFR gene. The most common type of aberrations was amplification (53.69%), followed by other mutations (38.79%) and fusions (5.64%). Concurrent FGFR fusion and amplification occurred in 1.88% patients. Of the 16 cancer types, except for head and neck cancer, osteogenic sarcoma, renal carcinoma, and lymphoma, all other cancer types had FGFR aberrations detected with colorectal cancer (31.03%) having the highest prevalence. Other relatively commonly affected cancers included: gastric cancer (16.78%), breast cancer (14.27%) and esophageal cancer (12.68%). FGFR1 amplification was the most common genetic alteration in CRC, breast cancer and lung cancer. FGFR2 amplification was more commonly seen in gastric cancer. Of the patients with FGFR aberrations, 57 patients, spanning 9 cancer types, had fusions. Among them, breast cancer patients are more likely to have concurrent FGFR amplification than other cancer types (p<0.001). ConclusionsOur study provides a comprehensive view of FGFR aberrations in Chinese cancer patients. Legal entity responsible for the studyYang Gao. FundingKey Research and Development Program of Hunan province (2016JC2039). DisclosureAll authors have declared no conflicts of interest.

Crouzon’s syndrome: a new surgical approach

Crouzon’s syndrome is a rare genetic disorder characterized by distinctive malformations of the skull and facial region, premature cranial suture closure is the most common skull abnormality, optic disc edema and proptosis are among the most common ocular findings. It is a genetic disorder of gene FGFR-2 (Fibroblast Growth Factor Receptor-2) in 95% of cases, and in 5% of cases, FGFR-3 (Fibroblast Growth Factor Receptor-3) mutation occurs.Once a suture becomes fused, growth perpendicular to that suture becomes restricted and the fused bones act as a single body structure. Compensatory growth occurs at the remaining open sutures to allow continued brain growth, resulting in abnormal bone growth and producing facial deformities.In the new born child, some potential problems that may need to be addressed include respiratory difficulties, feeding problems, neurologic complications such as hydrocephalus and the potential risk of developmental delay.We represent a literature review and a rare case of Crouzon’s Syndrome, who wanted facial correction to be done at the age of 24years. We planned two stage surgical procedure, for correction of facial deformity.Â

Clinical and Radiologic Evaluation of an Individual with Hypochondroplasia and a Novel FGFR3 Mutation

Hypochondroplasia (HCH), a skeletal dysplasia caused by mutations in the fibroblast growth factor receptor 3 ( FGFR3 ) gene, is characterized by disproportionate short stature. The p.Asn540Lys (p.N540K) mutation accounts for ∼50 to 70% of cases of HCH, but novel FGFR3 mutations are described. We present a family with disproportionately short stature and mild radiologic findings seen in a major public pediatric hospital in Argentina. A previously undescribed heterozygous missense variant in FGFR3, NM_000142.4:667C > T; p.(Arg223Cys) was identified. The predicted phenotype correlates well with the mild auxologic and radiologic characteristics observed. In this case, disproportionately short stature raised the suspicion of skeletal dysplasia.

The impact of chemo- and radiotherapy treatments on selfish de novo FGFR2 mutations in sperm of cancer survivors.

STUDY QUESTIONWhat effect does cancer treatment have on levels of spontaneous selfish fibroblast growth factor receptor 2 (FGFR2) point mutations in human sperm?SUMMARY ANSWERChemotherapy and radiotherapy do not increase levels of spontaneous FGFR2 mutations in sperm but, unexpectedly, highly-sterilizing treatments dramatically reduce the levels of the disease-associated c.755C > G (Apert syndrome) mutation in sperm.WHAT IS KNOWN ALREADYCancer treatments lead to short-term increases in gross DNA damage (chromosomal abnormalities and DNA fragmentation) but the long-term effects, particularly at the single nucleotide resolution level, are poorly understood. We have exploited an ultra-sensitive assay to directly quantify point mutation levels at the FGFR2 locus.STUDY DESIGN, SIZE, DURATION‘Selfish’ mutations are disease-associated mutations that occur spontaneously in the sperm of most men and their levels typically increase with age. Levels of mutations at c.752–755 of FGFR2 (including c.755C > G and c.755C > T associated with Apert and Crouzon syndromes, respectively) in semen post-cancer treatment from 18 men were compared to levels in pre-treatment samples from the same individuals (n = 4) or levels in previously screened population controls (n = 99).PARTICIPANTS/MATERIALS, SETTING, METHODSCancer patients were stratified into four different groups based on the treatments they received and the length of time for spermatogenesis recovery. DNA extracted from semen samples was analysed using a previously established highly sensitive assay to identify mutations at positions c.752–755 of FGFR2. Five to ten micrograms of semen genomic DNA was spiked with internal controls for quantification purposes, digested with MboI restriction enzyme and gel extracted. Following PCR amplification, further MboI digestion and a nested PCR with barcoding primers, samples were sequenced on Illumina MiSeq. Mutation levels were determined relative to the spiked internal control; in individuals heterozygous for a nearby common single nucleotide polymorphism (SNP), mutations were phased to their respective alleles.MAIN RESULTS AND THE ROLE OF CHANCEPatients treated with moderately-sterilizing alkylating regimens and who recovered spermatogenesis within <3 years after therapy (Group 3, n = 4) or non − alkylating chemotherapy and/or low gonadal radiation doses (Group 1, n = 4) had mutation levels similar to untreated controls. However, patients who had highly-sterilizing alkylating treatments (i.e. >5 years to spermatogenesis recovery) (Group 2, n = 7) or pelvic radiotherapy (Group 4, n = 3) exhibited c.755C > G mutation levels at or below background. Two patients (A and B) treated with highly-sterilizing alkylating agents demonstrated a clear reduction from pre-treatment levels; however pre-treatment samples were not available for the other patients with low mutation levels. Therefore, although based on their age we would expect detectable levels of mutations, we cannot exclude the possibility that these patients also had low mutation levels pre-treatment. In three patients with low c.755C > G levels at the first timepoint post-treatment, we observed increasing mutation levels over time. For two such patients we could phase the mutation to a nearby polymorphism (SNP) and determine that the mutation counts likely originated from a single or a small number of mutational events.LIMITATIONS, REASONS FOR CAUTIONThis study was limited to 18 patients with different treatment regimens; for nine of the 18 patients, samples from only one timepoint were available. Only 12 different de novo substitutions at the FGFR2 c.752–755 locus were assessed, two of which are known to be disease associated.WIDER IMPLICATIONS OF THE FINDINGSOur data add to the body of evidence from epidemiological studies and experimental data in humans suggesting that male germline stem cells are resilient to the accumulation of spontaneous mutations. Collectively, these data should provide physicians and health-care professionals with reassuring experimental-based evidence for counselling of male cancer patients contemplating their reproductive options several years after treatment.STUDY FUNDING/COMPETING INTEREST(S)This work was primarily supported by grants from the Wellcome (grant 091182 to AG and AOMW; grant 102 731 to AOMW), the University of Oxford Medical Sciences Division Internal Fund (grant 0005128 to GJM and AG), the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre Programme (to AG) and the US National Institutes of Health (to MLM). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. None of the authors has any conflicts of interest to declare.TRIAL REGISTRATION NUMBERNA

FGFR3S249C mutation promotes chemoresistance by activating Akt signaling in bladder cancer cells.

Fibroblast growth factor receptor 3 (FGFR3) is a high frequency mutant gene in bladder cancer (BCa) and has become a promising therapeutic target due to its involvement in cell proliferation and migration. However, whether and how FGFR3 mutations affects BCa cell chemosensitivity is unknown. The current study aimed to elucidate the role of the FGFR3S249C mutation in the development of chemoresistance in BCa cells. The results revealed that 97-7 (FGFR3S249C) cells had decreased sensitivity to cisplatin compared with 5637 (FGFR3WT) and T24 (FGFR3WT) cells. The ratio of phosphorylated-Akt/total-Akt was higher in 97-7 (FGFR3S249C) cells, which was reversed by knockdown of FGFR3. Furthermore, inhibition of Akt signaling by GDC0068 or LY294002 increased the cisplatin sensitivity of 97-7 (FGFR3S249C) cells. GDC0068 or LY294002 was also revealed to augment the effects of cisplatin on 97-7 (FGFR3S249C) cell proliferation and apoptosis. The results of the present study demonstrated that the FGFR3S249C mutation promotes chemoresistance in BCa cells by activating the Akt signaling pathway. The FGFR3S249C mutation may therefore be used as a predictor of chemosensitivity in patients with BCa.

SWOG S1400D (NCT02965378), a Phase II Study of the Fibroblast Growth Factor Receptor Inhibitor AZD4547 in Previously Treated Patients With Fibroblast Growth Factor Pathway–Activated Stage IV Squamous Cell Lung Cancer (Lung-MAP Substudy)

BackgroundS1400D is a biomarker-driven therapeutic substudy of Lung-MAP evaluating the fibroblast growth factor (FGF) receptor (FGFR) inhibitor AZD4547 in patients with FGF pathway-activated squamous cell. This is the first phase II trial to evaluate AZD4547 as a targeted approach in patients with previously treated FGFR-altered squamous cell NSCLC and is the first demonstration of successful implementation and conduct of a national umbrella protocol in this disease setting. MethodsEligible patients had tumoral FGFR alteration or mutation and had progressive disease after at least one line of platinum-based systemic therapy. Patients received AZD4547 80 mg twice daily orally. Primary endpoint was response by Response Evaluation Criteria in Solid Tumors version 1.1; secondary endpoints included progression-free survival, overall survival, and duration of response (DoR). ResultsNinety-two patients were assigned to S1400D, 43 were enrolled, and 27 AZD4547-treated patients were evaluable. Evaluable patients were predominantly white (n = 24, 89%), median age 66 years (range, 49–88 years old), and female (n = 7, 26%). FGFR alterations included FGFR1 amplification (n = 23; 85%), FGFR3 amplification (n = 2; 7%), FGFR3 S249C (n = 2; 7%), and FGFR3 fusion (n = 1; 4%). Treatment with ADZ4547 was well tolerated; grade 3 adverse events occurred in six patients, and one patient had grade 4 sepsis. Of 27 response-evaluable patients, 1 patient with FGFR3 S249C had unconfirmed partial response with a DoR of 1.5 months and 1 patient with FGFR1 amplification had a confirmed partial response with a DoR of 2.9 months (7%, 95% confidence interval [CI]: 0%–17%). Median progression-free survival and overall survival for the AZD4547-treated cohort were 2.7 months (95% CI: 1.4– 4.5 months) and 7.5 months (95% CI: 3.7–9.3 months). ConclusionsAZD4547 had an acceptable safety profile but minimal activity in this predominantly FGFR1/FGFR3–amplified cohort. Evaluation of other targeted agents in Lung-MAP is ongoing.

Cancer Mutations in FGFR2 Prevent a Negative Feedback Loop Mediated by the ERK1/2 Pathway.

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.

Correlation between FGFR mutation and PD-L1 expression of urinary bladder cancers: A real-world based biomarker study.

e16030 Background: Programmed cell death (PD)-1 / PD-ligand 1 (PD-L1) inhibitors have made a breakthrough mainly in the treatment of PD-L1 positive advanced urothelial bladder cancer (UBC). The effect of Fibroblast Growth Factor Receptor 3 (FGFR3) mutation on the treatment outcomes of PD-L1 treatment still remains unclear. Our goal was to assess the frequency of FGFR mutations in different tumor stages, in relation with PD-L1 status. Methods: Enrolled patients were diagnosed with UBC and underwent radical cystectomy between 2006-2016 at the University of Szeged, Hungary. FGFR3 mutation analysis by targeted next-generation sequencing and PD-L1 (28-8 DAKOR and SP142 VentanaR) tests were carried out from the most infiltrative area of tumors, in T0 cases from the earlier resection samples. The treatment and survival data were collected from the National Health Insurance Fund (NHIF), Hungary. Independence between covariates was tested using chi-square tests, survival analysis was performed using Kaplan-Meier models and Cox proportional hazards regression. Results: 215 of all 310 UBC samples (T0:19 (8.8%); superficial 43(20%); muscle invasive 41(19%); extraorgan 112 (52%)) could be tested for both PD-L1 and FGFR successfully. Pairwise dependency between tumor stage, FGFR3 mutation status and PD-L1 expression were all found to be significant (p &lt; 0.01). In cases of less advanced diseases FGFR mutation was more often detected. We have found that FGFR mutated samples are less likely to be PD-L1 positive than wild type ones. The effect of all covariates on survival was found to be in accordance with the effect of tumor stage. Conclusions: FGFR alteration frequency varied with stage of disease, with higher positivity rates in early stages, but that lower PD-L1 expression was observed in FGFR mutant patients across disease stages.

Nuclear Fibroblast Growth Factor Receptor Signaling in Skeletal Development and Disease.

Fibroblast growth factor receptor (FGFR) signaling regulates proliferation and differentiation during development and homeostasis. While membrane-bound FGFRs play a central role in these processes, the function of nuclear FGFRs is also critical. Here, we highlight mechanisms for nuclear FGFR translocation and the effects of nuclear FGFRs on skeletal development and disease. Full-length FGFRs, internalized by endocytosis, enter the nucleus through β-importin-dependent mechanisms that recognize the nuclear localization signal within FGFs. Alternatively, soluble FGFR intracellular fragments undergo nuclear translocation following their proteolytic release from the membrane. FGFRs enter the nucleus during the cellular transition between proliferation and differentiation. Once nuclear, FGFRs interact with chromatin remodelers to alter the epigenetic state and transcription of their target genes. Dysregulation of nuclear FGFR is linked to the etiology of congenital skeletal disorders and neoplastic transformation. Revealing the activities of nuclear FGFR will advance our understanding of 20 congenital skeletal disorders caused by FGFR mutations, as well as FGFR-related cancers.

ETV5 links the FGFR3 and Hippo signalling pathways in bladder cancer

Activating mutations of fibroblast growth factor receptor 3 (FGFR3) are common in urothelial carcinoma of the bladder (UC). Silencing or inhibition of mutant FGFR3 in bladder cancer cell lines is associated with decreased malignant potential, confirming its important driver role in UC. However, understanding of how FGFR3 activation drives urothelial malignant transformation remains limited. We have previously shown that mutant FGFR3 alters the cell-cell and cell-matrix adhesion properties of urothelial cells, resulting in loss of contact-inhibition of proliferation. In this study, we investigate a transcription factor of the ETS-family, ETV5, as a putative effector of FGFR3 signalling in bladder cancer. We show that FGFR3 signalling induces a MAPK/ERK-mediated increase in ETV5 levels, and that this results in increased level of TAZ, a co-transcriptional regulator downstream of the Hippo signalling pathway involved in cell-contact inhibition. We also demonstrate that ETV5 is a key downstream mediator of the oncogenic effects of mutant FGFR3, as its knockdown in FGFR3-mutant bladder cancer cell lines is associated with reduced proliferation and anchorage-independent growth. Overall this study advances our understanding of the molecular alterations occurring during urothelial malignant transformation and indicates TAZ as a possible therapeutic target in FGFR3-dependent bladder tumours.

FGFR3 mutation as a prognostic indicator in patients with urothelial carcinoma: A systematic review and meta-analysis.

411 Background: Mutations in the fibroblast growth factor receptor-3 (FGFR3) have been implicated in urothelial tumorigenesis. The role of FGFR3 inhibitors in urothelial carcinoma is being explored in clinical trials. Here we explore the association between FGFR3 mutations and survival in urothelial carcinoma. Methods: We conducted a systemic review of electronic databases to identify studies published 1985-2018. Studies were included if they described the associated between FGFR3 mutations and outcomes of non-muscle invasive (NMI) and muscle invasive (MI) urothelial carcinomas. We used a composite endpoint of progression-free and recurrence-free survival (PRFS). Analysis was performed in Revman software. Hazard ratios (HR) and the 95% confidence intervals (CI) were obtained and entered; and then weighted and pooled in a meta-analysis with random effect modelling. The statistical tests were two sided. Results: Twelve retrospective and prospective studies comprising a total of 2162 patients were included. Analysis was done for two groups. The first group, included 1651 patients with NMI urothelial carcinomas; 886 (53.6%) of these had FGFR3 mutation. Compared to FGFR3 wild type, FGFR3 mutation did not influence PRFS (HR = 1.01, CI = 0.79-1.29, p = 0.95); I2 42%. In the second analysis, 511 patients with NMI and MI urothelial carcinomas were evaluated; 30% (n = 151) of which had FGFR3 mutation. In this group, FGFR3 mutation was not associated with PRFS (HR = 1.46, CI = 0.45-4.71, p = 0.53); I2 90%. Conclusions: Our meta-analysis does not show an association between FGFR3 mutation status and PRFS in urothelial carcinoma. [Table: see text]

Abstract P5-04-25: Characterization of FGFR1/2 genetic alterations reveals novel fusions of FGFR1 in Chinese breast cancer

Abstract Background: Deregulation of fibroblast growth factor receptor 1 (FGFR1) signalling has been extensively studied in various tumor types, and has been implicated in driving endocrine resistance in breast cancer. Genetic alterations of FGFR1, especially FGFR1 amplification, is one of particularly important mechanisms leading to enhanced FGFR signaling in breast cancer. However, the prevalence of FGFR1/2 genetic variations in Chinese breast cancer patients has not been well explored. Methods: To investigate the characteristics of FGFR1 and FGFR2 genetic variations in Chinese breast cancer, we employed customized next-generation sequencing panel to screen the somatic mutation or copy number variations of FGFR1/2 in primary breast cancer tissues by using two ongoing breast cancer Cohorts, in which we have recruited 289 of early breast cancer patients (EBC Cohort) and 74 of advanced breast cancer patients (ABC Cohort). Results: In EBC Cohort, we found FGFR1 amplification in 9.0% (26/289) patients and FGFR2 amplification in 2.1% (6/289) patients, and also found 3 of somatic FGFR1 mutations (FGFR1 p.W4C; p.E334K; p.V396I ) and 2 of FGFR2 mutations (FGFR2 p.S702L; p.Y779*). Unlike the comparable prevalence of FGFR2 genetic variations in 2.8% (8/289) of EBC Cohort and 2.7% (2/74; one amplification event and one FGFR2 p.E499D mutation) of ABC Cohort, there were more FGFR1 genetic alterations in ABC Cohort (27%; 20/74 patients; p&amp;lt;0.001), including 19 events of FGFR1 amplification and 1 of FGFR1 c.2186+20G&amp;gt;A intron mutation. More importantly, we identified 5 novel FGFR1 fusion genes in our cohorts, including TACC1-FGFR1, FGFR1-KCNU1, FGFR1-MIR1268A, FGFR1-LZTS1-AS1 and FGFR1-RNF5P1. Although FGFR1-TACC1 fusion gene has been previously reported in breast cancer and TACC1 is fused to the C-terminal of FGFR1 protein leading to aberrant activation of FGFR1, we found TACC1 was fused to the N-terminal of FGFR1 at exon 6 of FGFR1 in our study. In addition, we identified and verified FGFR1-MIR1268A fusion gene at mRNA level using RNA-seq analysis, and further found this fusion gene might result in the truncation of FGFR1. Conclusions: Collectively, we characterized the prevalence of FGFR1/2 genetic alterations in Chinese breast cancer, and identified 5 of novel FGFR1 fusion genes. The potential roles for novel FGFR1 fusion genes in regulating breast cancer cellular biology and in affecting the efficacy of endocrine therapy have been under the investigation in our laboratory, and the result from which will help us better elucidate the molecular mechanism of FGFR1 in driving the resistance of endocrine therapy. This study was supported by funding from National Natural Science Foundation of China (Grant No. 81602645), Guangdong Provincial Natural Science Foundation (Grant No. 2016A030313768) and Research Funds from Guangzhou Science and Technology Bureau (Grant No. 201707010418 and 201804010430). Citation Format: Wang Y, Guo L, Cao L, Jia M, Wen L, Ren C, Zhang G, Liao N. Characterization of FGFR1/2 genetic alterations reveals novel fusions of FGFR1 in Chinese breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-04-25.

Nuclear FGFR2 regulates musculoskeletal integration within the developing limb.

Bent bone dysplasia syndrome (BBDS), a congenital skeletal disorder caused by dominant mutations in fibroblast growth factor receptor 2 (FGFR2), is characterized by bowed long bones within the limbs. We previously showed that the FGFR2 mutations in BBDS enhance nuclear and nucleolar localization of the receptor; however, exactly how shifts in subcellular distribution of FGFR2 affect limb development remained unknown. Targeted expression of the BBDS mutations in the lateral plate mesoderm of the developing chick induced angulated hindlimbs, a hallmark feature of the disease. Whole-mount analysis of the underlying skeleton revealed bent long bones with shortened bone collars and, in severe cases, dysmorphic epiphyses. Epiphyseal changes were also correlated with joint dislocations and contractures. Histological analysis revealed that bent long bones and joint defects were closely associated with irregularities in skeletal muscle patterning and tendon-to-bone attachment. The spectrum of limb phenotypes induced by the BBDS mutations were recapitulated by targeted expression of wild-type FGFR2 appended with nuclear and nucleolar localization signals. Our results indicate that the bent long bones in BBDS arise from disruptions in musculoskeletal integration and that increased nuclear and nucleolar localization of FGFR2 plays a mechanistic role in the disease phenotype. 248:233-246, 2019. © 2018 Wiley Periodicals, Inc.

Acanthosis nigricans in a Chinese girl with FGFR3 K650\u2009T mutation: a case report and literature review

BackgroundAcanthosis nigricans (AN) is a clinical manifestation featured by velvety brown plaques in skin folds that occurs in some hereditary and syndromic disorders. Fibroblast growth factor receptor 3 (FGFR3) mutations have been identified as one of the genetic causes of inherited AN.Case presentationA 17-year-old Chinese female had presented generalized acanthosis nigricans since she was 4 years old. She yielded no family history of short stature or AN. Apart from a short stature, no skeletal defects, neurological defects or other abnormalities were found. To identify the aetiology of the clinically diagnosed AN, we screened the proband for genetic mutations using whole exome sequencing. A heterozygous mutation (c.1949A > C, p.Lys650Thr) in FGFR3 was found in the proband. To date, 26 cases of AN harbouring this specific gene mutation have been reported in the literature, and only one child carried a de novo mutation instead of inheriting the specific mutation from their parents. The present case is the first-reported Chinese patient with isolated AN with a de novo K650 T mutation in FGFR3.ConclusionsWe reported a new case of AN caused by a heterozygous mutation (c.1949A > C, p.K650 T) in FGFR3, and review the past reports of AN with the same gene mutation. Sequencing of the FGFR3 gene is a feasible approach to identify the aetiology of AN, especially for early onset extensive AN.

Detection of G338R FGFR2 mutation in a Vietnamese patient with Crouzon syndrome.

Crouzon syndrome is a rare autosomal dominant genetic disorder, which causes the premature fusion of the cranial suture. Fibroblast growth factor receptor 2 (FGFR2) mutations are well-known causatives of Crouzon syndrome. The current study aimed to assess the FGFR2 gene associated with Crouzon syndrome in a Vietnamese family of three generations and to characterize their associated clinical features. The family included in the present study underwent complete clinical examination. A patient was clinically examined and presented with typical features of Crouzon syndrome including craniosynostosis, shallow orbits, ocular proptosis and midface hypoplasia. However the patient had normal hands and feet, a normal hearing ability and normal intelligence. Genomic DNA collected from all family members (except from a 16 week-old-foetus) and 200 unrelated control subjects from the same population was extracted from leukocytes obtained from peripheral blood samples. Genomic DNA was extracted from the 16-week-old foetus via the amniotic fluid of the mother. All coding sequences of FGFR2 were amplified via polymerase chain reaction and directly sequenced. A heterozygous FGFR2 missense mutation (c.1012G>C, p.G338R) in exon 10 was identified in the patient with Crouzon but not in other family members, the 16 week-old-foetus or the controls. This mutation was therefore determined to be the causative agent of Crouzon syndrome. In addition, a novel heterozygous silent mutation (c.1164C>T, p.I388I) in exon 11 of the FGFR2 gene was identified in the patient with Crouzon, his mother and the 16-week-old fetus, but not in other family members. The mutation in exon 10 of FGRF2 was confirmed via restriction-enzyme digestion. The gain of the BsoBI site confirmed the FGFR2 mutation in exon 10 of the patient with Crouzon. This molecular finding may provide useful information to aid clinicians in the diagnosis of Crouzon syndrome and may also aid early prenatal diagnoses.

Targeted therapies for advanced bladder cancer: new strategies with FGFR inhibitors.

Inhibitors of fibroblast growth factor receptor (FGFR) represent an outstanding treatment approach for selected patients with urothelial cancer (UC). These agents are changing the clinical approach to a subgroup of UC, the luminal-papillary subtype, characterized by FGFR mutations, fusions, or amplification. In this review, we provide an overview of the results of recent clinical trials on FGFR tyrosine kinase inhibitors (TKIs) currently in clinical development for the treatment of UC: erdafitinib, rogaratinib, infigratinib, and the monoclonal antibody vofatamab. The Food and Drug Administration recently granted accelerated approval to erdafitinib for patients with advanced UC with alterations of FGFR2 or FGFR3 after progression on platinum-based chemotherapy. We also look at future therapeutic options of combination regimens with immune-checkpoint inhibitors as strategies for improving the antitumor effects of this class of drug, and for preventing or delaying the development of resistance.