Targeting Fibroblast Growth Factor Receptor 1 for Treatment of Soft-Tissue Sarcoma

Abstract

Altered FGFR1 signaling has emerged as a therapeutic target in epithelial malignancies. In contrast, the role of FGFR1 in soft-tissue sarcoma (STS) has not been established. Prompted by the detection and subsequent therapeutic inhibition of amplified FGFR1 in a patient with metastatic leiomyosarcoma, we investigated the oncogenic properties of FGFR1 and its potential as a drug target in patients with STS. The frequency of amplification and overexpression, as assessed by FISH, microarray-based comparative genomic hybridization and mRNA expression profiling, SNP array profiling, and RNA sequencing, was determined in three patient cohorts. The sensitivity of STS cell lines with or without FGFR1 alterations to genetic and pharmacologic FGFR1 inhibition and the signaling pathways engaged by FGFR1 were investigated using viability assays, colony formation assays, and biochemical analysis. Increased copy number was detected in 74 of 190 (38.9%; cohort 1), 13 of 79 (16.5%; cohort 2), and 80 of 254 (31.5%; cohort 3) patients. overexpression occurred in 16 of 79 (20.2%, cohort 2) and 39 of 254 (15.4%; cohort 3) patients. Targeting of FGFR1 by RNA interference and small-molecule inhibitors (PD173074, AZD4547, BGJ398) revealed that the requirement for FGFR1 signaling in STS cells is dictated by FGFR1 expression levels, and identified the MAPK-ERK1/2 axis as critical FGFR1 effector pathway. These data identify as a driver gene in multiple STS subtypes and support FGFR1 inhibition, guided by patient selection according to the FGFR1 expression and monitoring of MAPK-ERK1/2 signaling, as a therapeutic option in this challenging group of diseases..

Precision oncology based on omics data: The NCT Heidelberg experience

“…This study revealed that FGFR inhibitor sensitivity in STS models is primarily determined by FGFR1 expression levels and supports further evaluation of FGFR inhibitor therapy in this group of diseases. 37 These first individual reports about successful personalized treatments and translational research projects originating from the MASTER program not only underscore the clinical need for broad testing of common genetic variants in rare and unclassifiable tumors, but also demonstrate the multitude of opportunities for translational research opened up by comprehensive genomic profiling in a clinical context.…”

Protein Tyrosine Phosphatase Receptor Type G (PTPRG) Controls Fibroblast Growth Factor Receptor (FGFR) 1 Activity and Influences Sensitivity to FGFR Kinase Inhibitors

“…The following antibodies were used: rabbit anti-FGFR1 (ab76464), rabbit antiClathrin heavy chain (ab21679), mouse anti-COTL1 (ab187608), and rabbit anti-SLC20A1 (ab177147) from Abcam; rabbit anti-FGFR1 (2144-1) from Epitomics; rabbit anti-VAMP4 (136002) from SYSY; mouse anti-phospho-FGFR (Tyr653/654) (#3476), rabbit anti-FGFR1 (#9740), rabbit anti-DYKDDDDK (FLAG) tag (#2368), rabbit anti-phospho-PLCG1 (Tyr783) (#14008), mouse anti-phospho-ERK1/2 (Thr202/Tyr204) (#9106), rabbit anti-RSK2 (#5528), rabbit anti-OAS1 (#14498) and rabbit anti-PTPN1 (#5311) from Cell Signaling Technology; mouse anti--tubulin (T6557), and mouse anti-FLAG M2 antibody (F-1804) from Sigma-Aldrich; mouse anti-EEA1 (610456) from BD transduction laboratories; rabbit anti-phospho-PLCG1 (Tyr783) (sc-12943-R), rabbit anti-FRS2 (sc-8318), and mouse anti-PLCG1 (sc-7290) from Santa Cruz Biotechnology; rabbit anti-HA epitope tag (600-401-384) from Rockland; mouse anti-MYC Tag (05-724) from Merck Millipore, human anti-EEA1 7 reading frame and XhoI and ApaI flanking sites into pEGFP-N1 cut with XhoI and ApaI using pcDNA3-hFGFR1 as template. pcDNA3-SBP-FGFR1 was made by introducing a sequence coding for the streptavidin-binding peptide (SBP) after the signal peptide in FGFR1 using a GeneArt Strings DNA fragment (Thermo Fisher Scientific).…”

“…FGFR overexpression and activating 4 mutations have recently been demonstrated to play an important role in several types of cancer, including sarcoma (e.g. osteosarcoma, rhabdomyosarcoma (RMS) and soft tissue sarcoma) (4)(5)(6)(7)(8). In addition, the FGFR-specific downstream signaling adaptor, the FGFR substrate 2 (FRS2), is overexpressed in liposarcoma and renders these cells sensitive to FGFR inhibitors (9, 10).…”

The integration of genomics testing and functional proteomics in the era of personalized medicine

“…RTKs are representative protooncogenes that are activated in various types of human cancers due to gene amplification, gene fusions, mutations in the coding region, or other alterations in the promoter/enhancer regions [8]. For example, FGFR family genes, including FGFR1, FGFR2, FGFR3, and FGFR4, are aberrantly activated in a variety of human cancers, such as breast cancer [9], cholangiocarcinoma [10], endometrial uterine cancer [11], gastric cancer [12], lung cancer [13], soft-tissue sarcoma [14], and urothelial carcinoma [15].…”