Fibroblast Growth Factor Receptor Gene Research Articles

Mild achondroplasia/hypochondroplasia with acanthosis nigricans, normal development, and a p.Ser348Cys FGFR3 mutation

Pathogenic allelic variants in the fibroblast growth factor receptor 3 (FGFR3) gene have been associated with a number of phenotypes including achondroplasia, hypochondroplasia, thanatophoric dysplasia, Crouzon syndrome with acanthosis nigricans (Crouzonodermoskeletal syndrome), and SADDAN (severe achondroplasia with developmental delay and acanthosis nigricans). Crouzon syndrome with acanthosis nigricans is caused by the pathogenic variant c.1172C>A (p.Ala391Glu) in the FGFR3 gene. The p.Lys650Thr pathogenic variant in FGFR3 has been linked to acanthosis nigricans without significant craniofacial or skeletal abnormalities. Recently, an infant with achondroplasia and a novel p.Ser348Cys FGFR3 mutation was reported. We describe the clinical history of an 8-year-old child with a skeletal dysplasia in the achondroplasia-hypochondroplasia spectrum, acanthosis nigricans, typical development, and the recently described p.Ser348Cys FGFR3 mutation.

A Functional Genetic Screen Identifies the Phosphoinositide 3-kinase Pathway as a Determinant of Resistance to Fibroblast Growth Factor Receptor Inhibitors in FGFR Mutant Urothelial Cell Carcinoma

Activating mutations and translocations of the FGFR3 gene are commonly seen in urothelial cell carcinoma (UCC) of the bladder and urinary tract. Several fibroblast growth factor receptor (FGFR) inhibitors are currently in clinical development and response rates appear promising for advanced UCC. A common problem with targeted therapeutics is intrinsic or acquired resistance of the cancer cells. To find potential drug targets that can act synergistically with FGFR inhibition, we performed a synthetic lethality screen for the FGFR inhibitor AZD4547 using a short hairpin RNA library targeting the human kinome in the UCC cell line RT112 (FGFR3-TACC3 translocation). We identified multiple members of the phosphoinositide 3-kinase (PI3K) pathway and found that inhibition of PIK3CA acts synergistically with FGFR inhibitors. The PI3K inhibitor BKM120 acted synergistically with inhibition of FGFR in multiple UCC and lung cancer cell lines having FGFR mutations. Consistently, we observed an elevated PI3K-protein kinase B pathway activity resulting from epidermal growth factor receptor or Erb-B2 receptor tyrosine kinase 3 reactivation caused by FGFR inhibition as the underlying molecular mechanism of the synergy. Our data show that feedback pathways activated by FGFR inhibition converge on the PI3K pathway. These findings provide a strong rationale to test FGFR inhibitors in combination with PI3K inhibitors in cancers harboring genetic activation of FGFR genes.

Fibroblast Growth Factor Receptor 1 (FGFR1), Partly Related to Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) and Microvessel Density, is an Independent Prognostic Factor for Non-Small Cell Lung Cancer.

BackgroundThis study aimed to explore the correlation between FGFR1 and clinical features, including survival analysis and the promotion of angiogenesis by fibroblast growth factor receptor 1 (FGFR1) and vascular endothelial growth factor receptor 2 (VEGFR2). FGFR1 gene amplification has been found in non-small cell lung cancer (NSCLC). However, the prognostic value of FGFR1 and the correlation between FGFR1 and clinical features are still controversial.Material/MethodsA total of 92 patients with NSCLC who underwent R0 resection between July 2006 and July 2008 were enrolled in the study. The expression of FGFR1, VEGFR2, and CD34 was detected by immunohistochemistry. The correlations between the aforementioned markers and the patients’ clinical features were analyzed by the chi-square test. The impact factors of prognosis were evaluated by Cox regression analyses.ResultsThe expression ratios of FGFR1 and VEGFR2 were 26.1% and 43.4%, respectively. The intensity of FGFR1 expression was related to VEGFR2 and histopathology. To some extent, the average microvessel density (MVD) had correlation to the expression of FGFR1 and VGEFR2. The pathological stages III–IV and high expression of FGFR1 were found to be independent prognostic factors.ConclusionsThe expression intensity of FGFR1 and VEGFR2 was associated with MVD, and the expression of FGFR1 is one of the independent prognostic indicators for NSCLC.

Thanatophoric Dysplasia; a Rare Case Report on a Congenital Anomaly

The rare form of skeletal dysplasia is thanatophoric dysplasia. The meaning for thanatophoric dysplasia is death bearing which is derived from Greek word. It occurs 1in 20,000 to 50,000. It is mainly due to mutations in the fibroblast growth factor receptor 3gene. Features of thanatophoric dysplasia are frontal bossing, prominent eyes, narrow thorax, protruded abdomen and bowed legs. The knowledge about this condition is useful in the fields of Anatomy, Paediatrics, Obstetrics and Gynaecology, Ultrasonagraphy and Genetics, for future research purpose.

Acanthosis nigricans in a Japanese boy with hypochondroplasia due to a K650T mutation in FGFR3.

.Acanthosis nigricans (AN) is observed in some cases of skeletal dysplasia. However, AN has occasionally been reported in patients with hypochondroplasia (HCH), and a clinical diagnosis is sometimes difficult when its physical and radiological features are mild. Mutations in the gene encoding the fibroblast growth factor receptor 3 (FGFR3) have been identified as the cause of some types of skeletal dysplasia, which is diagnostically useful. Here, we report the case of a 3-yr-old Japanese boy who presented with AN. His height, weight, head circumference, and arm span were 91.7 cm (–1.95 SD), 16.3 kg, 54.0 cm (+2.6 SD), and 88.0 cm, respectively. In addition to the AN, he also exhibited a mild height deficit and macrocephaly, which prompted a search for FGFR3 mutations, although no skeletal disproportion, exaggerated lumbar lordosis, or facial dysmorphism was observed, and only slight radiological abnormalities were noted. A definitive diagnosis of HCH was made based on FGFR3 gene analysis, which detected a heterozygous K650T mutation. Insulin insensitivity was not found to have contributed to the development of AN. In individuals with AN, careful assessments for symptoms of HCH are important, regardless of the presence or absence of a short stature, and FGFR3 gene analysis is recommended in such cases.

Targeting and Regulating of an Oncogene via Nanovector Delivery of MicroRNA using Patient-Derived Xenografts.

In precision cancer nanomedicine, the key is to identify the oncogenes that are responsible for tumorigenesis, based on which these genetic drivers can be each specifically regulated by a nanovector-directed, oncogene-targeted microRNA (miRNA) for tumor suppression. Fibroblast Growth Factor Receptor 3 (FGFR3) is such an oncogene. The molecular tumor-subtype harboring FGFR3 genomic alteration has been identified via genomic sequencing and referred to as the FGFR3-driven tumors. This genomics-based tumor classification provides further rationale for the development of the FGFR3-targeted miRNA replacement therapy in treating patients with FGFR3 gene abnormity. However, successful miRNA therapy has been hampered by lacking of an efficient delivery vehicle. In this study, a nanovector is developed for microRNA-100 (miR-100) -mediated FGFR3 regulation. The nanovector is composed of the mesoporous magnetic clusters that are conjugated with ternary polymers for efficient miRNA in-vivo delivery. The miRNA-loading capacity of the nanovector is found to be high due to the polycation polymer functionalized mesoporous structure, showing excellent tumor cell transfection and pH-sensitive miRNA release. Delivery of miR-100 to cancer cells effectively down-regulates the expression of FGFR3, inhibits cell proliferation, and induces cell apoptosis in vitro. Patient-derived xenografts (PDXs) are used to evaluate the efficacy of miRNA delivery in the FGFR3-driven tumors. Notably, sharp contrasts are observed between the FGFR3-driven tumors and those without FGFR3 genomic alteration. Only the FGFR3-driven PDXs are significantly inhibited via miR-100 delivery while the non-FGFR3-driven PDXs are not affected, showing promise of precision cancer nanomedicine.

An mRNA Gene Expression–Based Signature to Identify FGFR1-Amplified Estrogen Receptor–Positive Breast Tumors

Fibroblast growth factor receptor 1 (FGFR1) amplification drives poor prognosis and is an emerging therapeutic target. We sought to construct a multigene mRNA expression signature to efficiently identify FGFR1-amplified estrogen receptor-positive (ER+) breast tumors. Five independent breast tumor series were analyzed. Genes discriminative for FGFR1 amplification were screened transcriptome-wide by receiver operating characteristic analyses. The METABRIC series was leveraged to construct/evaluate four approaches to signature composition. A locked-down signature was validated with 651 ER+formalin-fixed, paraffin-embedded tissues (the University of British Columbia-tamoxifen cohort). A NanoString nCounter assay was designed to profile selected genes. For a gold standard, FGFR1 amplification was determined by fluorescent in situ hybridization (FISH). Prognostic effects of FGFR1 amplification were assessed by survival analyses. Eight 8p11-12 genes (ASH2L, BAG4, BRF2, DDHD2, LSM1, PROSC, RAB11FIP1, and WHSC1L1) together with the a priori selected FGFR1 gene, highly discriminated FGFR1 amplification (area under the receiver operating characteristic curve ≥0.82, all genes and all cohorts). The nine-gene signature Call-FGFR1-amp accurately identified FGFR1 FISH-amplified ER+tumors in the University of British Columbia-tamoxifen cohort (specificity,0.94; sensitivity,0.96) and exhibited prognostic effects (disease-specific survival hazard ratio, 1.57; 95% CI, 1.14-2.16; P=0.005). Call-FGFR1-amp includes several understudied 8p11-12 amplicon-driven oncogenes and accurately identifies FGFR1-amplified ER+breast tumors. Our study demonstrates an efficient approach to diagnosing rare amplified therapeutic targets with FISH as a confirmatory assay.

FGFR gene alterations in lung squamous cell carcinoma are potential targets for the multikinase inhibitor nintedanib.

Fibroblast growth factor receptor (FGFR) gene alterations are relatively frequent in lung squamous cell carcinoma (LSCC) and are a potential targets for therapy with FGFR inhibitors. However, little is known regarding the clinicopathologic features associated with FGFR alterations. The angiokinase inhibitor nintedanib has shown promising activity in clinical trials for non‐small cell lung cancer. We have now applied next‐generation sequencing (NGS) to characterize FGFR alterations in LSCC patients as well as examined the antitumor activity of nintedanib in LSCC cell lines positive for FGFR1 copy number gain (CNG). The effects of nintedanib on the proliferation of and FGFR signaling in LSCC cell lines were examined in vitro, and its effects on tumor formation were examined in vivo. A total of 75 clinical LSCC specimens were screened for FGFR alterations by NGS. Nintedanib inhibited the proliferation of FGFR1 CNG‐positive LSCC cell lines in association with attenuation of the FGFR1–ERK signaling pathway in vitro and in vivo. FGFR1 CNG (10.7%), FGFR1 mutation (2.7%), FGFR2 mutation (2.7%), FGFR4 mutation (5.3%), and FGFR3 fusion (1.3%) were detected in LSCC specimens by NGS. Clinicopathologic features did not differ between LSCC patients positive or negative for FGFR alterations. However, among the 36 patients with disease recurrence after surgery, prognosis was significantly worse for those harboring FGFR alterations. Screening for FGFR alterations by NGS warrants further study as a means to identify patients with LSCC recurrence after surgery who might benefit from nintedanib therapy.

FGFR3 silencing by siRNA inhibits invasion of A549 cells.

The present study identified that fibroblast growth factor receptor 3 (FGFR3) was significantly upregulated in bone metastasis of lung adenocarcinoma. RNA interference (RNAi) is a powerful approach for treating a wide range of human diseases, including cancer, through downregulating the expression of selected genes. In the present study, the invasiveness of A549 cells cultured in vitro was altered by small interfering (si)RNA targeting FGFR3, and the regulatory effect of silencing FGFR3 on the expression levels of E-cadherin and matrix metalloproteinase (MMP)9 was investigated. Human lung adenocarcinoma A549 cells were transfected with synthetic specific siRNAs targeting a fragment of the FGFR3 gene (namely, siRNA-855, siRNA-1447 and siRNA-2076) or with negative control (NC) siRNA. Cells were divided into five groups (A, siRNA-855 group; B, siRNA-1447 group; C, siRNA-2076 group; D, NC-siRNA group; and E, blank control group). The effect of the above siRNAs targeting FGFR3 on the invasion capacity of A549 cells was detected by Transwell assay. siRNAs against FGFR3 were transfected into A549 cells with by Lipofectamine® 2000, and the expression levels of FGFR3, E-cadherin and MMP9 were measured by reverse transcription-quantitative polymerase chain reaction and western blot assay. The experimental findings indicated that the expression levels of FGFR3 and MMP9 were significantly reduced in the siRNA-FGFR3-transfected groups (A-C groups), compared with those in the D and E groups (P<0.01). In addition, the expression levels of E-cadherin were markedly elevated in the A-C groups, compared with those in the D and E groups (P<0.01). There was no significant difference in E-cadherin expression between the A-C groups, or between the D and E groups (P>0.05). These results indicated that siRNA-FGFR3 was able to decrease the invasiveness of A549 cells, inhibit the expression of MMP9 and increase the expression of E-cadherin by downregulating the expression of FGFR3. Taken together, the results of the present study indicated that the upregulation of E-cadherin expression and the downregulation of MMP9 expression are able to inhibit the migration of A549 cells, and siRNA silencing FGFR3 acts as a tumor suppressor in these cells.

Genetic variants in FGFR2 and TNRC9 genes are associated with breast cancer risk in Pakistani women.

Single nucleotide polymorphisms (SNPs) lead to genetic differences in breast cancer (BC) susceptibility among women from different ethnicities. The present study aimed at investigating the involvement of SNPs of three genes, including fibroblast growth factor receptor2 (FGFR2), trinucleotide-repeat-containing9 (TNRC9) and mitogen-activated protein kinase kinase kinase1 (MAP3K1), as risk factors for the development of BC. A case‑control study (90‑100 cases; 90‑100 controls) was performed to evaluate five genetic variants of three genes, including FGFR2 (SNPs: rs1219648, rs2981582), TNRC9 (SNPs: rs8051542, rs3803662) and MAP3K1 (SNP: rs889312) as BC risk factors in Pakistani women. Significant associations were observed between BC risk and two SNPs of FGFR2 [rs2981582 (P=0.005), rs1219648 (P=9.08e‑006)] and one SNP of TNRC9 [rs3803662) (P=0.012)] in Pakistani women. On examining the different interactions of these SNPs with various clinicopathological characteristics, all three associated genetic variants, rs2981582 rs1219648 and rs3803662, exhibited a greater predisposition to sporadic, in comparison to familial, BC. Furthermore, there was an increased effect of BC risk between haplotype combinations of the two SNPs of FGFR2 (rs2981582 and rs1219648) in Pakistani women. The results of the present study suggest that variants of FGFR2 and TNRC9 may contribute to the genetic susceptibility of BC in Pakistani women.

Fibroblast Growth Factor Receptor (FGFR): A New Target for Non-small Cell Lung Cancer Therapy.

Lung cancer is still the leading cause of cancer related death worldwide. Fibroblast growth factor receptor (FGFR) is a tirosine-kinase receptor that is seen to be amplified or mutated in non-small cell lung cancer (NSCLC) and it plays a crucial role in tumour development and maintenance. The authors analyzed the state of the art of FGFR by reviewing the current literature. Fibroblast growth factor (FGF)-FGFR pathway and their aberrations are described, with the evaluation of their possible prognostic role in NSCLC and in particular in squamous cell carcinomas, in which FGFR is more often amplified. New therapeutic agents targeting FGFR signaling have been developed and are now in clinical evaluation. Dysregulation of FGF signaling in tumour cells is related to FGFR gene amplification or mutation, although it is still uncertain which of these aberrations represents a real predictor of response to specific inhibitors. However, recent evidence has questioned whether FGFR is a real target in squamous cell histology. The effectiveness of FGFR inhibitors is also still unclear since there are no clinical data on selected patients. Moreover, the management of specific side effects related to inhibition of the physiological role of FGF should be more thorough.

Interactions between FGFR2 and RSK2-implications for breast cancer prognosis.

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 materialThe online version of this article (doi:10.1007/s13277-016-5266-9) contains supplementary material, which is available to authorized users.

Abstract 4933: In Situ analysis of FGFR2 RNA and comparison with FGFR2 gene copy number by dual-color in situ hybridization in a large cohort of gastric cancer patients

Abstract Gastric cancer is the 3rd most common cause of cancer-related mortality worldwide, thus new treatment options are urgently needed. In gastric cancer, over-expression of the tumor-promoting tyrosine kinase receptor fibroblast growth factor receptor 2 (FGFR2) has been described, representing a potential therapeutic target. FGFR2 expression in gastric cancer has been reported to be heterogeneous. Most methods for detection of RNA in FFPE (formalin fixed paraffin embedded) do not provide spatial resolution for assessment of tumor heterogeneity. Here we used a novel RNA in situ technique called RNAscope. The technology allows visual investigation of FGFR2 transcription on FFPE slides. Samples from 1036 gastric adenocarcinoma patients who underwent surgery in National Cancer Center Hospital East (Chiba, Japan) were assembled in tissue micro-arrays and analyzed by RNAscope. A total of 578 samples were also analyzed by DISH to determine gene amplification. Using these tissue based methods we were able to assess the localization and heterogeneity of both FGFR2 gene amplification and RNA expression. Strong FGFR2 gene amplification (FGFR2:CEN10 &amp;gt;10) was detected in 2% of 578 samples. Moderate FGFR2 gene amplification (FGFR2:CEN10 between 2 and 10) was seen in 8% of the samples. High FGFR2 RNA expression (score 4+) was seen in 4% of 718 evaluable samples. Gene amplification and RNA expression were closely correlated. All samples with dense clusters of score 4+ RNA showed FGFR2:CEN10 ratios &amp;gt;10. The identical tumor areas showed high gene amplification and RNA expression. FGFR2 RNA and gene amplification was highly heterogeneous in the tissue. Only 0.4% of the samples showed homogeneous FGFR2 expression in &amp;gt;80% of the tumor cells. High RNA expression intensity was associated with a more homogeneous expression pattern compared to moderate FGFR2 expression. In early stage I/II gastric cancer samples with score 4+ RNA expression are mostly of the differentiated type. RNA score 4+ patients of grade III/IV gastric cancer were mostly of undifferentiated histology. In a subset of 195 samples with available data cMet IHC 3+ and Her2 positivity status were not mutually exclusive with regards to FGFR2 RNA Score 4+ expression. In a multivariant analysis FGFR2 RNA expression was associated with patient outcome. Gastric cancer patients with score 4+ RNA expression had a shorter progression free survival compared to patients with score 0-3. Interestingly, there was a trend for patients with homogeneous score 3+ RNA expression, but not heterogeneous score 3+ expression, to show shorter PFS and OS suggesting that patients with high intensity or homogeneous FGFR2 RNA expression may define a subgroup of patients with gastric cancer. Patients with homogenous or strong focal FGFR2 expression might therefore be candidates for FGFR2 directed therapies in gastric cancer. Citation Format: Yasutoshi Kuboki, Christoph A. Schatz, Sabine Jabusch, Karl Koechert, Janine Feng, Sabine Wittemer-Rump, Karl Ziegelbauer, Thomas Krahn, Akiko Nagatsuma, Atsushi Ochiai. In Situ analysis of FGFR2 RNA and comparison with FGFR2 gene copy number by dual-color in situ hybridization in a large cohort of gastric cancer patients. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4933.

Abstract 116: Study of TERT promoter and FGFR3 mutations in upper-tumor urothelial carcinomas

Abstract Background: Mutations in the promoter of the telomerase reverse transcriptase (TERT) and fibroblast growth factor receptor 3 (FGFR3) genes represent the most recurrent somatic alterations in urothelial carcinomas of the bladder. However, data regarding frequency and prognostic values of these alterations in upper-tumor urothelial carcinoma (UTUC) remain limited. Methods: DNA was extracted from 31 UTUC including 12 cases arising in the ureter and 19 in renal pelvis. Somatic mutations of TERT promoter and FGFR3 gene were assessed by Sanger sequencing. The generated sequences were analyzed by seqscape and mutational status of each of those genes were correlated with clinico-pathological tumor features. Disease-free survival and overall survival were estimated using the Kaplan-Meier method. Results: Median patient's age was 72 years (range: 41-83) with a male predominance (90.3%). Mutation status of TERT and FGFR3 were obtained in all tumors. Out of 31 UTUC, 81% were classified as high-grade including 56% which were muscle-invasive (≥pT2). TERT and FGFR3 mutations were detected in 19 (61%) and 14 (46%) tumors, respectively. Of note, 8 (26%) out of them harbored both mutations. In the TERT-mutated subgroup, we observed higher incidence of men as compared to TERT non-mutated subgroup (p = 0.04); in addition, we did not identify any other significant differences regarding other clinico-pathological features. This was also the case for FGFR3 mutations, although we observed a higher frequency in tumors arising in the ureter (66.6%) as compared to those located in renal pelvis (28.5%) (p = 0.11). Neither mutations of FGFR3 nor TERT were associated with progression-free survival and patient's overall survival. Conclusion: Our study identified a high rate of somatic mutations in FGFR3 and TERT which were similar between muscle-invasive and non-muscle invasive tumors as well as between tumors arising in the ureter or renal pelvis. As targeted inhibitors are being investigated in this setting, these results might have implications for patient's management. Citation Format: Roger Mouawad, Souheyla Bensalma, Xiaoping Su, Frederick Allanic, Eva Comperat, Morgan Rouprêt, JeanPhillipe Spano, Gabriel Malouf, David Khayat. Study of TERT promoter and FGFR3 mutations in upper-tumor urothelial carcinomas. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 116.

Abstract 3990: FGFR3 mutations as novel oncogenic targets

Abstract Fibroblast growth factors (FGFs) are a family of homologous secreted glycoproteins involved in signaling pathways responsible for embryonic development, cell proliferation, survival, and migration. FGF activity is mediated by four transmembrane fibroblast growth factor receptors (FGFRs) which are receptor tyrosine kinases. Typically, FGF binding induces FGFR dimerization, leading to phosphorylation of the intracellular tyrosine kinase domain. This leads to downstream activation of multiple signaling pathways, including the mitogen-activated protein kinase (MAPK), PI3K/AKT, signal transducer and activator of transcription (STAT), and phospholipase-C-γ cascades. Deregulated FGFR activity, through mutations or translocations, is often associated with oncogenic events. Aberrations in FGFR genes have been observed in several tumor types including bladder, gastric, colorectal, ovarian, and hematologic cancers. To date, several FGFR3 mutations have been identified in bladder cancer. In this study, we developed a TaqMan qRT-PCR-based approach to detect four FGFR3 mutations in formalin-fixed paraffin embedded tissue (FFPET) samples. Cell lines overexpressing FGFR3 mutations were generated to determine impact on cell signaling, and sensitivity to the small-molecule pan-FGFR inhibitor JNJ-42756493. To determine the role and significance of these FGFR3 mutations in cancer, mutation expression constructs were designed and individually transfected into normal rat kidney epithelial cells. Cells harboring the FGFR3 mutations exhibited anchorage-independent growth, increased proliferation, and showed increased sensitivity to the FGFR inhibitor JNJ-42756493 in vitro compared to parental lines. These findings underline the oncogenic potential of the FGFR3 mutation genes and highlight their unique potential as predictive biomarkers in the selection of patients for FGFR-targeted therapy. Citation Format: Gabriela Martinez Cardona, Dana Gaffney, Katherine Bell, Joseph Portale, Matthew Dunworth, Matthew Lorenzi, Suso Platero, Jayaprakash Karkera. FGFR3 mutations as novel oncogenic targets. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3990.

Abstract CT080: A phase II study of JNJ-42756493, a pan-FGFR tyrosine kinase inhibitor, in patients with metastatic or unresectable urothelial cancer (UC) harboring FGFR gene alterations

Abstract Background: Current treatment options for metastatic UC remain limited, and tolerability is a concern in many patients. Alterations in the fibroblast growth factor receptor (FGFR) pathway are implicated in development of non-muscle-invasive bladder cancer; FGFR3 mutations or FGFR translocations are present in ∼10-20% of patients with metastatic UC. Treatment with pan-FGFR (FGFR1-4) inhibitor JNJ-42756493 resulted in promising antitumor activity in a phase 1 trial in patients with advanced solid tumors, including 3 partial responses among 8 patients with UC (Tabernero J, et al. J Clin Oncol. 2015). Safety was manageable and as anticipated with a potent FGFR inhibitor. This phase 2 open-label study of JNJ-42756493 (NCT02365597) is being conducted to determine efficacy and safety of 2 different dose regimens in patients with metastatic or unresectable UC with specific FGFR translocations or mutations. Methods: Eligible patients must have disease progression following chemotherapy for metastatic or surgically unresectable UC or relapse within 12 months of the last dose of neoadjuvant/adjuvant chemotherapy. There is no limit on number of prior lines of treatment. Prior immunotherapy (eg, programmed-death 1/death-ligand 1 inhibitor) is allowed. Enrollment of cisplatin-ineligible (chemotherapy naïve) pts is allowed. Patients must have measurable disease (Response Evaluation Criteria In Solid Tumors version 1.1); Eastern Cooperative Oncology Group performance status ? 2; and adequate bone marrow, liver, and kidney function (creatinine clearance ? 40 mL/min). Patients with uncontrolled cardiovascular disease or baseline phosphate persistently above the upper limit of normal are not eligible. Eligible patients are randomized to 1 of 2 oral dose regimens of JNJ-42756493 in a 28-day cycle: an intermittent (10 mg/day for 7 days followed by 7 days off drug) or a continuous (6 mg/day) regimen until a dose regimen is selected. Approximately 110 patients will be treated at the selected dose regimen. Primary end point is objective response rate; secondary end points include progression-free survival, duration of response, overall survival, safety, biomarker, and pharmacokinetic assessments. This trial is currently enrolling in 14 countries. Citation Format: Arlene O. Siefker-Radtke, Begoña Mellado, Karel Decaestecker, John M. Burke, Anne O’ Hagan, Anjali Avadhani, Bob Zhong, Ademi Santiago-Walker, Peter De Porre, Sabine Brookman-May, Jesus Garcia-Donas. A phase II study of JNJ-42756493, a pan-FGFR tyrosine kinase inhibitor, in patients with metastatic or unresectable urothelial cancer (UC) harboring FGFR gene alterations. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT080.

FGFR3-TACC3 fusion in solid tumors: mini review.

Fibroblast growth factor receptors (FGFR) are transmembrane kinase proteins with growing importance in cancer biology given the frequency of molecular alterations and vast interface with multiple other signaling pathways. Furthermore, numerous FGFR inhibitors in clinical development demonstrate the expanding therapeutic relevance of this pathway. Indeed, results from early phase clinical trials already indicate that a subset of patients with advanced tumors derive benefit from FGFR targeted therapies. FGFR gene aberrations and FGFR gene rearrangements are relatively rare in solid malignancies. The recently described FGFR3-TACC3 fusion protein has a constitutively active tyrosine kinase domain and promotes aneuploidy. We summarize the prevalence data on FGFR3-TACC3 fusions among different histological tumor types and the preliminary evidence that this rearrangement represents a targetable molecular aberration in some patients with solid tumors.

FGFR inhibitors: Effects on cancer cells, tumor microenvironment and whole-body homeostasis (Review).

Fibroblast growth factor (FGF)2, FGF4, FGF7 and FGF20 are representative paracrine FGFs binding to heparan-sulfate proteoglycan and fibroblast growth factor receptors (FGFRs), whereas FGF19, FGF21 and FGF23 are endocrine FGFs binding to Klotho and FGFRs. FGFR1 is relatively frequently amplified and overexpressed in breast and lung cancer, and FGFR2 in gastric cancer. BCR-FGFR1, CNTRL-FGFR1, CUX1-FGFR1, FGFR1OP-FGFR1, MYO18A-FGFR1 and ZMYM2-FGFR1 fusions in myeloproliferative neoplasms are non-receptor-type FGFR kinases, whereas FGFR1-TACC1, FGFR2-AFF3, FGFR2-BICC1, FGFR2-PPHLN1, FGFR3-BAIAP2L1 and FGFR3-TACC3 fusions in solid tumors are transmembrane-type FGFRs with C-terminal alterations. AZD4547, BGJ398 (infigratinib), Debio-1347 and dovitinib are FGFR1/2/3 inhibitors; BLU9931 is a selective FGFR4 inhibitor; FIIN-2, JNJ-42756493, LY2874455 and ponatinib are pan-FGFR inhibitors. AZD4547, dovitinib and ponatinib are multi-kinase inhibitors targeting FGFRs, colony stimulating factor 1 receptor (CSF1R), vascular endothelial growth factor (VEGF)R2, and others. The tumor microenvironment consists of cancer cells and stromal/immune cells, such as cancer-associated fibroblasts (CAFs), endothelial cells, M2-type tumor-associating macrophages (M2-TAMs), myeloid-derived suppressor cells (MDSCs) and regulatory T cells. FGFR inhibitors elicit antitumor effects directly on cancer cells, as well as indirectly through the blockade of paracrine signaling. The dual inhibition of FGF and CSF1 or VEGF signaling is expected to enhance the antitumor effects through the targeting of immune evasion and angiogenesis in the tumor microenvironment. Combination therapy using tyrosine kinase inhibitors (FGFR or CSF1R inhibitors) and immune checkpoint blockers (anti-PD-1 or anti-CTLA-4 monoclonal antibodies) may be a promising choice for cancer patients. The inhibition of FGF19-FGFR4 signaling is associated with a risk of liver toxicity, whereas the activation of FGF23-FGFR4 signaling is associated with a risk of heart toxicity. Endocrine FGF signaling affects the pathophysiology of cancer patients who are prescribed FGFR inhibitors. Whole-genome sequencing is necessary for the detection of promoter/enhancer alterations of FGFR genes and rare alterations of other genes causing FGFR overexpression. To sustain the health care system in an aging society, a benefit-cost analysis should be performed with a focus on disease-free survival and the total medical cost before implementing genome-based precision medicine for cancer patients.

FGFR1 as a prognostic biomarker and potential therapeutic target in head and neck squamous cell carcinoma.

6057Background: FGFR1 (fibroblast growth factor receptor 1) is a promising therapeutic target in multiple types of solid tumors, including head and neck squamous cell carcinoma (HNSCC). FGFR inhibitors have shown great therapeutic value in preclinical models. However, resistance remains a major setback. In this study we have investigated the prognostic value of FGFR1 expression in HNSCC, the therapeutic relevance of targeting FGFR with AZD4547, and potential resistant mechanisms. Methods: Immunohistochemistry and fluorescence in situ hybridization were applied on tissue microarrays to investigate FGFR1 protein expression and FGFR1 gene copy-numbers in 452 HNSCC. The sensitivity of HNSCC cell lines to AZD4547, either as single or combination treatment with gefitinib, was assessed using long-term colony formation assays and biochemical analysis. Results: FGFR1 protein overexpression occurred in 82% (36/44) of HPV-positive HNSCC and 75% (294/392) of HPV-negative HNSCC and relates with poor overall survival a...

A phase 2 study of JNJ-42756493, a pan-FGFR tyrosine kinase inhibitor, in patients (pts) with metastatic or unresectable urothelial cancer (UC) harboring FGFR gene alterations.

TPS4575Background: Current treatment options for metastatic UC remain limited, and tolerability is a concern in many pts. Alterations in the fibroblast growth factor receptor (FGFR) pathway are imp...