Fibroblast Growth Factor Receptor Research Articles

Influence of temperature on embryonic development of Pontastacus leptodactylus freshwater crayfish, and characterization of growth and osmoregulation related genes

Narrow clawed crayfish, Pontastacus (Astacus) leptodactylus, represents an ecologically and economically valuable freshwater species. Despite the high importance of artificial breeding for conservation purpose and aquaculture potential, hatching protocols have not been developed so far in this species. Further, limited knowledge exists regarding the artificial egg incubation, the temperature effect on embryonic development, hatching synchronization and hatching rate. In the present study we investigated the temperature increase (from 17 oC to 22oC) effects in two different embryonic developmental stages of P. leptodactylus. Furthermore, two primer pairs for the Fibroblast Growth Factor Receptor 4 (FGFR4) gene cDNA amplification were successfully designed, characterising for the first time the FGFR4 gene in P. leptodactylus in relation to different developmental stages and temperatures. Apart from the FGFR4 gene, the Na+/K+-ATPase α-subunit expression was also explored. Both the FGFR4 and Na+/K+-ATPase α-subunit expression levels were higher in embryos closer to hatching. Egg incubation at 22oC for seven days led to significant increase of FGFR4 expression in embryos from earlier developmental stages. Nevertheless, temperature increase did not affect FGFR4 expression in eggs from latter developmental stages and Na+/K+-ATPase α-subunit expression in all developmental stages. Temperature increase represents therefore probably a promising strategy for accelerating hatching in freshwater crayfish particularly in early developmental stages. Specifically, our results indicate that FGFR4 expression increased in embryonic stages closer to hatching and that temperature influences significantly its expression in embryos from earlier developmental stages. Overall, these findings can provide a better understanding of artificial egg incubation of P. leptodactylus, and therefore can be employed for the effective management of this species, both for economic and biodiversity retention reasons.

Curcumin Alone and Combined With PI3K Inhibitors Elicits Positive Effects on Oropharyngeal Cancer Cell Lines Regardless of HPV Status.

Human papillomavirus positive (HPV+) oropharyngeal squamous cell carcinoma (OPSCC) is rising in incidence. Compared to HPV-negative (HPV-) OPSCC, HPV+ cases have a better 5-year survival. With its severe side-effects, today's chemoradiotherapy has not improved outcome compared to radiotherapy alone, so new therapies are needed. Mutations in phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), fibroblast growth factor receptor 3 (FGFR3) and cell division cycle 27 (CDC27) are found in HPV+ OPSCC, and in vitro targeted therapy combining PI3K and FGFR inhibitors showed synergistic effects. Here the effects of targeting CDC27 with curcumin with/without various inhibitors or cisplatin on OPSCC cell lines were examined. Curcumin was administered to HPV+ OPSCC cell lines CU-OP-2, CU-OP-3 and CU-OP-20, and HPV- CU-OP-17 with/without PI3K, cyclin-dependent kinase 4/6, FGFR, poly (ADP-ribose) polymerase or WEE1 inhibitors (BYL719, PD-0332991, JNJ-42756493, BMN-673 and MK-1775, respectively), or cisplatin. The cell lines were then assessed for 72 h after treatment for viability, proliferation and cytotoxicity. Curcumin led to dose-dependent responses with reduced viability and proliferation; upon combining it with BYL719, additional positive effects were found for most OPSCC lines grown as monolayers, and these effects were validated in CU-OP-2 cells grown as spheroids. Curcumin with MK-1775 or PD-0332991 also elicited some positive effects on CU-OP-2 and CU-OP-17 cells. Curcumin alone led to dose-dependent responses and when combined with BYL719, positive effects were revealed, as they were when it was combined with MK-1775 or PD-0332991, suggesting a potential use of some of these combinations for HPV+ OPSCC.

Muscle-Invasive Bladder Cancer With Hydronephrosis Exhibits a High Frequency of Mutations in Fibroblast Growth Factor Receptor 3 Gene.

Recent studies have reported conflicting findings regarding the significance of hydronephrosis (HN) in muscle-invasive bladder cancer (MIBC). The molecular characteristics of MIBC with HN are unclear, therefore, we aimed to address the gaps in previous research and elucidate HN's molecular significance in patients with MIBC. Clinical, genetic, and imaging information on bladder cancer patients enrolled in The Cancer Genome Atlas were obtained from public databases to analyze the association between the presence of hydronephrosis and genetic alterations and molecular subtyping. A total of 108 patients who underwent total cystectomy for MIBC at the Hiroshima University Hospital were enrolled in the study to verify the association between HN and renal function with patient prognosis. We observed a statistically significant difference in the distribution of molecular subtypes (p=0.0146). The proportion of patients with the luminal papillary subtype was approximately twice as high in patients with HN (48.8%) than in those without HN (25.0%). The mutation frequency of fibroblast growth factor receptor (FGFR) 3 was approximately three-fold higher in patients with HN (20.9%) than in those without HN (7.1%). Multivariate analysis, which considered HN and estimated glomerular filtration rate as confounding factors in our MIBC cohort, revealed that reduced renal function, but not HN, was an independent predictor for overall survival. MIBC presenting HN exhibits a high frequency of mutations in the FGFR3 gene. In addition, not HN itself, but reduced renal function due to HN may worsen the prognosis for MIBC.

Single-nucleus transcriptomics of epicardial adipose tissue from female pigs reveals effects of exercise training on resident innate and adaptive immune cells

BackgroundCoronary artery disease (CAD) is a leading cause of death in women. Epicardial adipose tissue (EAT) secretes cytokines to modulate coronary artery function, and the release of fatty acids from EAT serves as a readily available energy source for cardiomyocytes. However, despite having beneficial functions, excessive amounts of EAT can cause the secretion of proinflammatory molecules that increase the instability of atherosclerotic plaques and contribute to CAD progression. Although exercise mitigates CAD, the mechanisms by which exercise impacts EAT are unknown. The Yucatan pig is an excellent translational model for the effects of exercise on cardiac function. Therefore, we sought to determine if chronic aerobic exercise promotes an anti-inflammatory microenvironment in EAT from female Yucatan pigs.MethodsSexually mature, female Yucatan pigs (n = 7 total) were assigned to sedentary (Sed, n = 3) or exercise (Ex, n = 4) treatments, and coronary arteries were occluded (O) with an ameroid to mimic CAD or remained non-occluded (N). EAT was collected for bulk (n = 7 total) and single nucleus transcriptomic sequencing (n = 2 total, 1 per exercise treatment).ResultsBased on the bulk transcriptomic analysis, exercise upregulated S100 family, G-protein coupled receptor, and CREB signaling in neurons canonical pathways in EAT. The top networks in EAT affected by exercise as measured by bulk RNA sequencing were SRC kinase family, fibroblast growth factor receptor, Jak-Stat, and vascular endothelial growth factor. Single nucleus transcriptomic analysis revealed that exercise increased the interaction between immune, endothelial, and mesenchymal cells in the insulin-like growth factor pathway and between endothelial and other cell types in the platelet endothelial cell adhesion molecule 1 pathway. Sub-clustering revealed nine cell types in EAT, with fibroblast and macrophage populations predominant in O-Ex EAT and T cell populations predominant in N-Ex EAT. Unlike the findings for exercise alone as a treatment, there were not increased interactions between endothelial and mesenchymal cells in O-Ex EAT. Coronary artery occlusion impacted the most genes in T cells and endothelial cells. Genes related to fatty acid metabolism were the most highly upregulated in non-immune cells from O-Ex EAT. Sub-clustering of endothelial cells revealed that N-Ex EAT separated from other treatments.ConclusionsAccording to bulk transcriptomics, exercise upregulated pathways and networks related to growth factors and immune cell communication. Based on single nucleus transcriptomics, aerobic exercise increased cell-to-cell interaction amongst immune, mesenchymal, and endothelial cells in female EAT. Yet, exercise was minimally effective at reversing alterations in gene expression in endothelial and mesenchymal cells in EAT surrounding occluded arteries. These findings lay the foundation for future work focused on the impact of exercise on cell types in EAT.

Epithelial UNC-23 limits mechanical stress to maintain glia-neuron architecture in C. elegans

For an organ to maintain correct architecture and function, its diverse cellular components must coordinate their size and shape. Although cell-intrinsic mechanisms driving homotypic cell-cell coordination are known, it is unclear how cell shape is regulated across heterotypic cells. We find that epithelial cells maintain the shape of neighboring sense-organ glia-neuron units in adult Caenorhabditis elegans (C.elegans). Hsp co-chaperone UNC-23/BAG2 prevents epithelial cell shape from deforming, and its loss causes head epithelia to stretch aberrantly during animal movement. In the sense-organ glia, amphid sheath (AMsh), this causes progressive fibroblast growth factor receptor (FGFR)-dependent disruption of the glial apical cytoskeleton. Resultant glial cell shape alteration causes concomitant shape change in glia-associated neuron endings. Epithelial UNC-23 maintenance of glia-neuron shape is specific both spatially, within a defined anatomical zone, and temporally, in a developmentally critical period. As all molecular components uncovered are broadly conserved across central and peripheral nervous systems, we posit that epithelia may similarly regulate glia-neuron architecture cross-species.

Targeting FGFR1 by β,β-dimethylacrylalkannin suppresses the proliferation of colorectal cancer in cellular and xenograft models

BackgroundColorectal cancer (CRC) continues to be a major global health challenge, ranking as a top cause of cancer-related mortality. Alarmingly, the five-year survival rate for CRC patients hovers around a mere 10–30 %. The disruption of fibroblast growth factor receptor (FGFRs) signaling pathways is significantly implicated in the onset and advancement of CRC, presenting a promising target for therapeutic intervention in CRC management. Further investigation is essential to comprehensively elucidate FGFR1′s function in CRC and to create potent therapies that specifically target FGFR1. PurposeThis study aims to demonstrate the oncogenic role of FGFR1 in colorectal cancer and to explore the potential of β,β-dimethylacrylalkannin (β,β-DMAA) as a therapeutic option to inhibit FGFR1. MethodsIn this research, we employed a comprehensive suite of techniques including tissue array, kinase profiling, computational docking, knockdown assay to predict and explore the inhibitor of FGFR1. Furthermore, we utilized kinase assay, pull-down, cell proliferation tests, and Patient derived xenograft (PDX) mouse models to further investigate a novel FGFR1 inhibitor and its impact on the growth of CRC. ResultsIn our research, we discovered that FGFR1 protein is markedly upregulated in colorectal cancer tissues, suggesting a significant role in regulating cellular proliferation, particularly in patients with colorectal cancer. Furthermore, we conducted a computational docking, kinase profiling analysis, simulation and identified that β,β-DMAA could directly bind with FGFR1 within ATP binding pocket domain. Cell-based assays confirmed that β,β-DMAA effectively inhibited the proliferation of colon cancer cells and also triggered cell cycle arrest, apoptosis, and altered FGFR1-mediated signaling pathways. Moreover, β,β-DMAA effectively attenuated the development of PDX tumors in mice that were FGFR1-positive, with no notable toxicity observed. In summary, our study highlights the pivotal role of FGFR1 in colorectal cancer, suggesting that inhibiting FGFR1 activity could be a promising strategy for therapeutic intervention. We present strong evidence that targeting FGFR1 with β,β-DMAA is a viable approach for the management of colorectal cancer. Given its low toxicity and high efficacy, β,β-DMAA, as an FGFR1 inhibitor, warrants further investigation in clinical settings for the treatment of FGFR1-positive tumors.

RAPID resistance to BET inhibitors is mediated by FGFR1 in glioblastoma

Bromodomain and extra-terminal domain (BET) proteins are therapeutic targets in several cancers including the most common malignant adult brain tumor glioblastoma (GBM). Multiple small molecule inhibitors of BET proteins have been utilized in preclinical and clinical studies. Unfortunately, BET inhibitors have not shown efficacy in clinical trials enrolling GBM patients. One possible reason for this may stem from resistance mechanisms that arise after prolonged treatment within a clinical setting. However, the mechanisms and timeframe of resistance to BET inhibitors in GBM is not known. To identify the temporal order of resistance mechanisms in GBM we performed quantitative proteomics using multiplex-inhibitor bead mass spectrometry and demonstrated that intrinsic resistance to BET inhibitors in GBM treatment occurs rapidly within hours and involves the fibroblast growth factor receptor 1 (FGFR1) protein. Additionally, small molecule inhibition of BET proteins and FGFR1 simultaneously induces synergy in reducing GBM tumor growth in vitro and in vivo. Further, FGFR1 knockdown synergizes with BET inhibitor mediated reduction of GBM cell proliferation. Collectively, our studies suggest that co-targeting BET and FGFR1 may dampen resistance mechanisms to yield a clinical response in GBM.

Design, synthesis and biological evaluation of novel 2-hydroxy-1 H-indene-1,3(2 H)-dione derivatives as FGFR1 inhibitors

Fibroblast growth-factor receptor (FGFR) is a potential target for cancer therapy. We synthesised a novel series of FGFR1 inhibitors bearing quinoline, quinoxalin and isoquinoline using a synthetic strategy employing a one pot reaction, yielding 2-hydroxy-1H-indene-1,3(2H)-dione. Structural elucidation via IR, NMR and HRMS analyses is complemented by a proposed mechanistic pathway. All newly-synthesised compounds were evaluated in vitro for their inhibitory activities against FGFR-1. The most potent derivatives were 9a, 9b, 9c and 7b with IC50 = 5.7, 3.3, 4.1 and 3.1 μM, respectively, supported by molecular docking studies which probed the binding interactions of these compounds within the active site of the kinase.

Predictive and Prognostic Biomarkers and Tumor Antigens for Targeted Therapy in Urothelial Carcinoma.

Urothelial carcinoma (UC) is the fourth most prevalent cancer amongst males worldwide. While patients with non-muscle-invasive disease have a favorable prognosis, 25% of UC patients present with locally advanced disease which is associated with a 10-15% 5-year survival rate and poor overall prognosis. Muscle-invasive bladder cancer (MIBC) is associated with about 50% 5 year survival when treated by radical cystectomy or trimodality therapy; stage IV disease is associated with 10-15% 5 year survival. Current therapeutic modalities for MIBC include neoadjuvant chemotherapy, surgery and/or chemoradiation, although patients with relapsed or refractory disease have a poor prognosis. However, the rapid success of immuno-oncology in various hematologic and solid malignancies offers new targets with tremendous therapeutic potential in UC. Historically, there were no predictive biomarkers to guide the clinical management and treatment of UC, and biomarker development was an unmet need. However, recent and ongoing clinical trials have identified several promising tumor biomarkers that have the potential to serve as predictive or prognostic tools in UC. This review provides a comprehensive summary of emerging biomarkers and molecular tumor targets including programmed death ligand 1 (PD-L1), epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), fibroblast growth factor receptor (FGFR), DNA damage response and repair (DDR) mutations, poly (ADP-ribose) polymerase (PARP) expression and circulating tumor DNA (ctDNA), as well as their clinical utility in UC. We also evaluate recent advancements in precision oncology in UC, while illustrating limiting factors and challenges related to the clinical application of these biomarkers in clinical practice.

Dapagliflozin promotes browning of white adipose tissue through the FGFR1-LKB1-AMPK signaling pathway

BackgroundObesity is associated with a wide variety of metabolic disorders that impose significant burdens on patients and society. The “browning” phenomenon in white adipose tissue (WAT) has emerged as a promising therapeutic strategy to combat metabolic disturbances. However, though the anti-diabetic drug dapagliflozin (DAPA) is thought to promote “browning,” the specific mechanism of this was previously unclear.MethodsIn this study, C57BL/6 J male mice were used to establish an obesity model by high-fat diet feeding, and 3T3-L1 cells were used to induce mature adipocytes and to explore the role and mechanism of DAPA in “browning” through a combination of in vitro and in vivo experiments.ResultsThe results show that DAPA promotes WAT "browning" and improves metabolic disorders. Furthermore, we discovered that DAPA activated "browning" through the fibroblast growth factor receptors 1-liver kinase B1-adenosine monophosphate-activated protein kinase signaling pathway.ConclusionThese findings provide a rational basis for the use of DAPA in treating obesity by promoting the browning of white adipose tissue.

Elucidating the Role of Wildtype and Variant FGFR2 Structural Dynamics in (Dys)Function and Disorder.

The fibroblast growth factor receptor 2 (FGFR2) gene is one of the most extensively studied genes with many known mutations implicated in several human disorders, including oncogenic ones. Most FGFR2 disease-associated gene mutations are missense mutations that result in constitutive activation of the FGFR2 protein and downstream molecular pathways. Many tertiary structures of the FGFR2 kinase domain are publicly available in the wildtype and mutated forms and in the inactive and activated state of the receptor. The current literature suggests a molecular brake inhibiting the ATP-binding A loop from adopting the activated state. Mutations relieve this brake, triggering allosteric changes between active and inactive states. However, the existing analysis relies on static structures and fails to account for the intrinsic structural dynamics. In this study, we utilize experimentally resolved structures of the FGFR2 tyrosine kinase domain and machine learning to capture the intrinsic structural dynamics, correlate it with functional regions and disease types, and enrich it with predicted structures of variants with currently no experimentally resolved structures. Our findings demonstrate the value of machine learning-enabled characterizations of structure dynamics in revealing the impact of mutations on (dys)function and disorder in FGFR2.

Discovery of N-(4-((6-(3,5- Dimethoxyphenyl)-9H-purine derivatives as irreversible covalent FGFR inhibitors

Fibroblast growth factor receptor (FGFR) is an attractive target for cancer therapy, but existing FGFR inhibitors appear to hardly meet the demand for clinical application. Herein, a number of irreversible covalent FGFR inhibitors were designed and synthesized by selecting several five- and six-membered azaheterocycles as parent scaffold with different substituents to take over the hydrophobic region in the active pocket of FGFR proteins. Among the resulting target compounds, III-30 showed the most potent effect on enzyme activity inhibition and anti-proliferative activity against the tested cancer cell lines. Significantly, III-30 could inhibit the enzyme activity by achieving irreversible covalent binding with FGFR1 and FGFR4 proteins. It could also regulate FGFR-mediated signaling pathway and mitochondrial apoptotic pathway to promote cancer cell apoptosis and inhibit cancer cell invasion and metastasis. Moreover, III-30 had a good metabolic stability and showed relatively potent anti-tumor activity in the MDA-MB-231 xenograft tumor mice model.

Predictive insights into plant-based compounds as fibroblast growth factor receptor 1 inhibitors: a combined molecular docking and dynamics simulation study

The discovery of novel therapeutic agents with potent anticancer activity remains a critical challenge in drug development. Natural products, particularly bioactive phytoconstituents derived from plants, have emerged as promising sources for anticancer drug discovery. In this study, we used virtual screening techniques to explore the potential of bioactive phytoconstituents as inhibitors of fibroblast growth factor receptor 1 (FGFR1), a key signaling protein implicated in cancer progression. We used virtual screening techniques to analyze phytoconstituents extracted from the IMPPAT 2.0 database. Our primary objective was to discover promising inhibitors of FGFR1. To ensure the selection of promising candidates, we initially filtered the molecules based on their physicochemical properties. Subsequently, we performed binding affinity calculations, PAINS, ADMET, and PASS filters to identify nontoxic and highly effective hits. Through this screening process, one phytocompound, namely Mundulone, emerged as a potential lead. This compound demonstrated an appreciable affinity for FGFR1 and exhibited specific interactions with the ATP-binding site residues. To gain further insights into the conformational dynamics of Mundulone and the reference FGFR1 inhibitor, Lenvatinib, we conducted time-evolution analyses employing 200 ns molecular dynamics simulations (MDS) and essential dynamics. These analyses provided valuable information regarding the dynamic behavior and stability of the compounds in complexes with FGFR1. Overall, the findings indicate that Mundulone exhibits promising binding affinity, specific interactions, and favorable drug profiles, making it a promising lead candidate. Further experimental analysis will be necessary to confirm its effectiveness and safety profiles for therapeutic advancement in the cancer field. Communicated by Ramaswamy H. Sarma

Role of liver FGF21-KLB signaling in ketogenic diet-induced amelioration of hepatic steatosis

BackgroundThe effectiveness of ketogenic diet (KD) in ameliorating fatty liver has been established, although its mechanism is under investigation. Fibroblast growth factor 21 (FGF21) positively regulates obesity-associated metabolic disorders and is elevated by KD. FGF21 conventionally initiates its intracellular signaling via receptor β-klotho (KLB). However, the mechanistic role of FGF21-KLB signaling for KD-ameliorated fatty liver remains unknown. This study aimed to delineate the critical role of FGF21 signaling in the ameliorative effects of KD on hepatic steatosis.MethodsEight-week-old C57BL/6 J mice were fed a chow diet (CD), a high-fat diet (HFD), or a KD for 16 weeks. Adeno-associated virus-mediated liver-specific KLB knockdown mice and control mice were fed a KD for 16 weeks. Phenotypic assessments were conducted during and after the intervention. We investigated the mechanism underlying KD-alleviated hepatic steatosis using multi-omics and validated the expression of key genes.ResultsKD improved hepatic steatosis by upregulating fatty acid oxidation and downregulating lipogenesis. Transcriptional analysis revealed that KD dramatically activated FGF21 pathway, including KLB and fibroblast growth factor receptor 1 (FGFR1). Impairing liver FGF21 signaling via KLB knockdown diminished the beneficial effects of KD on ameliorating fatty liver, insulin resistance, and regulating lipid metabolism.ConclusionKD demonstrates beneficial effects on diet-induced metabolic disorders, particularly on hepatic steatosis. Liver FGF21-KLB signaling plays a critical role in the KD-induced amelioration of hepatic steatosis.

Safety and efficacy of anlotinib combined with taxane and lobaplatin in neoadjuvant treatment of clinical stage II/III triple-negative breast cancer in China (the neoALTAL trial): a single-arm, phase 2 trial

Anlotinib is a new type of tyrosine kinase inhibitor that targets vascular endothelial growth factor receptors 1/2/3, platelet-derived growth factor receptors α/β, and fibroblast growth factor receptors 1-4 and c-Kit, with a broad spectrum of inhibitory effects on tumor angiogenesis and growth. It has been proven effective in HER2-negative metastatic breast cancer, but its efficacy in early-stage triple-negative breast cancer (TNBC) is unknown. This phase 2 study aims to evaluate the efficacy and safety of adding anlotinib to neoadjuvant chemotherapy in patients with TNBC. Patients with clinical stage II/III TNBC were treated with 5 cycles of anlotinib (12mg, d1-14, q3w) plus 6 cycles of taxanes (docetaxel 75 mg/m2 ,d1, q3w or nab-paclitaxel 125 mg/m2, d1 and d8, q3w) and lobaplatin (30 mg/m2, d1, q3w), followed by surgery. The primary endpoint was pathological complete response (pCR; ypT0/is ypN0) and the secondary endpoints include breast pCR (bpCR), axillary pCR (apCR), residual cancer burden (RCB), objective response rate (ORR), survival, and safety. Exploratory endpoints were efficacy biomarkers based on Fudan University Shanghai Cancer Center Immunohistochemical (FUSCC IHC) classification for TNBC and next-generation sequencing (NGS) of DNA from tumor tissue and blood samples of patients with 425-gene panel. This trial is registered with www.chictr.org.cn (ChiCTR2100043027). From Jan 2021 to Aug 2022, 48patients were assessed and 45 were enrolled. All patients received at least one dose of study treatment and underwent surgery. The median age was 48.5 years (SD: 8.7), 71% were nodal involved, and 20% had stage III. In the intention-to-treat population, 26 out of 45patients achieved pCR (57.8%; 90% CI, 44.5%-70.3%), and 39 achieved residual cancer burden class 0-I (86.7%; 95% CI, 73.2%-94.9%). The bpCR and apCR rate were 64.4% (29/45) and 71.9% (23/32), respectively. No recurrence or metastasis occurred during the short-term follow-up. Based on the FUSCC IHC-based subtypes, the pCR rates were 68.8% (11/16) for immunomodulatory subtype, 58.3% (7/12) for basal-like immune-suppressed subtype and 33.3% (4/12) for luminal androgen receptor subtype, respectively. NGS revealed that the pCR were 77% (10/13) and 50% (14/28) in MYC-amplified and wild-type patients, respectively, and 78% (7/9) and 53% (17/32) in gBRCA1/2-mutated and wild-type patients, respectively. The median follow-up time of the study was 14.9 months (95% CI: 13.5-16.3 months). There was no disease progression or death during neoadjuvant therapy. No deaths occurred during postoperative follow-up. In the safety population (N=45), Grade 3 or 4 treatment emergent adverse events occurred in 29patients (64%), and the most common events were neutropenia (38%), leukopenia (27%), thrombocytopenia (25%), anemia (13%), and hypertension (13%), respectively. The addition of anlotinib to neoadjuvant chemotherapy showed manageable toxicity and encouraging antitumor activity for patients with clinical stage II/III TNBC. Chongqing Talents Project, Chongqing Key Project of Technology Innovation and Application Development and Chongqing Outstanding Youth Natural Science Foundation.

Development of Highly Potent and Selective Covalent FGFR4 Inhibitors Based on SNAr Electrophiles.

Fibroblast growth factor receptor 4 (FGFR4) is thought to be a driver in several cancer types, most notably in hepatocellular carcinoma. One way to achieve high potency and isoform selectivity for FGFR4 is covalently targeting a rare cysteine (C552) in the hinge region of its kinase domain that is not present in other FGFR family members (FGFR1-3). Typically, this cysteine is addressed via classical acrylamide electrophiles. We demonstrate that noncanonical covalent "warheads" based on nucleophilic aromatic substitution (SNAr) chemistry can be employed in a rational manner to generate highly potent and (isoform-)selective FGFR4 inhibitors with a low intrinsic reactivity. Key compounds showed low to subnanomolar potency, efficient covalent inactivation kinetics, and excellent selectivity against the other FGFRs, the kinases with an equivalent cysteine, and a representative subset of the kinome. Moreover, these compounds achieved nanomolar potencies in cellular assays and demonstrated good microsomal stability, highlighting the potential of SNAr-based approaches in covalent inhibitor design.

Phase 1b Trial Evaluating Tolerability and Activity of Targeted Fibroblast Growth Factor Receptor Inhibition in Localized Upper Tract Urothelial Carcinoma.

We initiated a biomarker-informed preoperative study of infigratinib, a fibroblast growth factor receptor (FGFR) inhibitor, in patients with localized upper tract urothelial carcinoma (UTUC), a population with high unmet needs and tumor with a high frequency of FGFR3 alterations. Patients with localized UTUC undergoing ureteroscopy or nephroureterectomy/ureterectomy were enrolled on a phase 1b trial (NCT04228042). Once-daily infigratinib 125 mg by mouth × 21 days (28-day cycle) was given for 2 cycles. Tolerability was monitored by Bayesian design and predefined stopping boundaries. The primary endpoint was tolerability, and the secondary endpoint was objective response based on tumor mapping, done after endoscopic biopsy and post-trial surgery. Total planned enrollment: 20 patients. Targeted sequencing performed using a NovaSeq 6000 solid tumor panel. From May 2021 to November 2022, 14 patients were enrolled, at which point the trial was closed due to termination of all infigratinib oncology trials. Two patients (14.3%) had treatment-terminating toxicities, well below the stopping threshold. Responses occurred in 6 (66.7%) of 9 patients with FGFR3 alterations. Responders had median tumor size reduction of 67%, with 3 of 5 patients initially planned for nephroureterectomy/ureterectomy converted to ureteroscopy. Median follow-up in responders was 24.7 months (14.9-28.9). In this first trial of targeted therapy for localized UTUC, FGFR inhibition was well tolerated and had significant activity in FGFR3 altered tumors. Renal preservation was enabled in a substantial proportion of participants. These data support the design of a biomarker-driven phase 2 trial of FGFR3 inhibition in this population with significant unmet clinical needs.

Low-dose infigratinib increases bone growth and corrects growth plate abnormalities in an achondroplasia mouse model.

Achondroplasia (ACH), the most common form of disproportionate short stature, is caused by gain-of-function point mutations in fibroblast growth factor receptor 3 (FGFR3). Abnormally elevated activation of FGFR3 modulates chondrocyte proliferation and differentiation via multiple signaling pathways, such as the MAPK pathway. Using a mouse model mimicking ACH (Fgfr3Y367C/+), we have previously shown that daily treatment with infigratinib (BGJ398), a selective and orally bioavailable FGFR1-3 inhibitor, at a dose of 2mg/kg, significantly increased bone growth. In this study, we investigated the activity of infigratinib administered at substantially lower doses (0.2 and 0.5mg/kg, given once daily) and using an intermittent dosing regimen (1mg/kg every 3days). Following a 15-day treatment period, these low dosages were sufficient to observe significant improvement of clinical hallmarks of ACH such as growth of the axial and appendicular skeleton and skull development. Immunohistological labeling demonstrated the positive impact of infigratinib on chondrocyte differentiation in the cartilage growth plate and the cartilage end plate of the vertebrae. Macroscopic and microcomputed analyses showed enlargement of the foramen magnum area at the skull base, thus improving foramen magnum stenosis, a well-recognized complication in ACH. No changes in FGF23 or phosphorus levels were observed, indicating that the treatment did not modify phosphate homeostasis. This proof-of-concept study demonstrates that infigratinib administered at low doses has the potential to be a safe and effective therapeutic option for children with ACH.

Abstract LB162: Tinengotinib in patients with advanced solid tumors harboring actionable FGFR1-3 mutations

Abstract Background: Fibroblast growth factor receptor (FGFR) alterations occur across various malignancies and are potent oncogenic drivers in multiple tumor types. FGFR inhibitors have demonstrated efficacy in several cancers with FGFR alterations. Tinengotinib is a novel kinase inhibitor with high potency to a variety of FGFR 1/2/3 kinase domain mutations and has shown promising efficacy in several ongoing clinical studies. Here, we present pooled data of tinengotinib in previously treated solid tumor patients (pts) with actionable FGFR1-3 mutations from four trials (NCT03654547, NCT04742959, NCT04919642, NCT05253053). Methods: Eligible pts received tinengotinib orally once daily (daily dose ranging from 5-12mg) until disease progression. Analyses of best overall response (BOR) rate, disease control rate (DCR), median progression-free survival (mPFS), median duration of response (mDOR) and treatment-related adverse events (TRAEs) were performed. Results: As of 3-Aug-2023, 53 solid tumor pts with actionable FGFR1-3 mutations were enrolled between Dec-2019 to Aug-2023 in the US and China. The median follow-up time was 14.5 (range, 3.3-43.8) months. Median age was 58 years (range, 29-83). Most pts were female (62%), had ECOG of 1 (68%) and were heavily pretreated with 55% having ≥3 lines of prior antitumor therapy. The most frequent FGFR mutation enrolled was in FGFR2 (77%) followed by FGFR1 (19%) and FGFR3 (11%). 25 pts (47%) had received prior therapy with FGFR inhibitor. A total of 45 pts were efficacy-evaluable, including cholangiocarcinoma (CCA, n=25), colon cancer (n=5), breast cancer (n=3), prostate cancer (n=3), head and neck cancer (n=3), urothelial cancer (n=3), pancreatic cancer (n=1), gastric cancer (n=1) and leiomyosarcoma (n=1). mPFS reached 6.83 (95% CI, 4.90-8.34) months. Partial responses were observed in 16/45 (35.6%) pts across 6 distinct tumor types, including CCA, breast, prostate, urothelium, colon and head and neck cancer. mDOR was 6.74 (95% CI, 3.52-9.46) months. For 44 pts with measurable target lesions per RECISTv1.1, the BOR rate and DCR were 36.4% and 86.4%, respectively. For 22 pts with prior FGFR inhibitor, mPFS was 5.98 (95% CI, 3.75-9.10) months and their BOR rate and DCR were 40.9% and 86.4%. TRAEs were reported in 46 (86.8%) pts, with 13 (24.5%) Grade (G) 1-2, 30 (56.6%) G3, 2 (3.8%) G4, and no G5. The most common TRAEs (≥20%) were hypertension, stomatitis, diarrhea, nausea, blood thyroid stimulating hormone increased, fatigue and anemia. Side effects were manageable and reversible with dose hold and/or dose reduction. Conclusions: We observed promising clinical benefit with tinengotinib in heavily pretreated solid tumor pts with FGFR1-3 mutations. The side effects profile was manageable and no new safety signals have been identified. Further research is planned to evaluate the safety and efficacy of tinengotinib in pts with FGFR1-3 mutations across a wider variety of tumor types. Citation Format: Sarina A. Piha-Paul, Chih-Yi "Andy" Liao, Lionel Fonkoua, Amit MahipaI, Sanjay Goel, Christos Fountzilas, Lin Shen, Daneng Li, Dustin Deming, Farshid Dayyani, Weiqing Han, Zuoxing Niu, Jean Fan, Peng Peng, Hui Wang, Peng Huang, Frank Wu, Milind Javle. Tinengotinib in patients with advanced solid tumors harboring actionable FGFR1-3 mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB162.

Fibroblast growth factor receptor inhibitors mitigate the neuropathogenicity of Borrelia burgdorferi or its remnants ex vivo.

In previous studies, we showed that fibroblast growth factor receptors (FGFRs) contribute to inflammatory mediator output from primary rhesus microglia in response to live Borrelia burgdorferi. We also demonstrated that non-viable B. burgdorferi can be as pathogenic as live bacteria, if not more so, in both CNS and PNS tissues. In this study we assessed the effect of live and non-viable B. burgdorferi in inducing FGFR expression from rhesus frontal cortex (FC) and dorsal root ganglion (DRG) tissue explants as well as their neuronal/astrocyte localization. Specific FGFR inhibitors were also tested for their ability to attenuate inflammatory output and apoptosis in response to either live or non-viable organisms. Results show that in the FC, FGFR2 was the most abundantly expressed receptor followed by FGFR3 and FGFR1. Non-viable B. burgdorferi significantly upregulated FGFR3 more often than live bacteria, while the latter had a similar effect on FGFR1, although both treatments did affect the expressions of both receptors. FGFR2 was the least modulated in the FC tissues by the two treatments. FGFR1 expression was more prevalent in astrocytes while FGFR2 and FGFR3 showed higher expression in neurons. In the DRG, all three receptor expressions were also seen, but could not be distinguished from medium controls by immunofluorescence. Inhibition of FGFR1 by PD166866 downregulated both inflammation and apoptosis in both FC and DRG in response to either treatment in all the tissues tested. Inhibition of FGFR1-3 by AZD4547 similarly downregulated both inflammation and apoptosis in both FC and DRG in response to live bacteria, while with sonicated remnants, this effect was seen in one of the two FC tissues and 2 of 3 DRG tissues tested. CCL2 and IL-6 were the most downregulated mediators in the FC, while in the DRG it was CXCL8 and IL-6 in response to FGFR inhibition. Downregulation of at least two of these three mediators was observed to downregulate apoptosis levels in general. We show here that FGFR inhibition can be an effective anti-inflammatory treatment in antibiotic refractive neurological Lyme. Alternatively, two biologics may be needed to effectively curb neuroinflammation and pathology in the CNS and PNS.