Fibroblast Growth Factor Receptor Research Articles

Network pharmacology, molecular docking and molecular dynamics simulation of chalcone scaffold-based compounds targeting breast cancer receptors

Compounds with a chalcone scaffold-based structure have demonstrated promising anticancer biological activity. However, the molecular interactions between chalcone scaffold-based compounds and breast cancer-associated proteins remain unclear. Through network pharmacology, molecular docking, and molecular dynamics (MD) simulation analyses, compounds with a chalcone scaffold-based structure were evaluated for their interaction with potential breast cancer targets. The compounds were retrieved from the ASINEX database, resulting in 575,302 compounds. A total of 342 compounds with chalcone scaffold-based structures were discovered. From the 342 compounds that was analysed, ten were chosen due to their adherence to Lipinski’s rule, having an appropriate range of lipophilicity (LOGP), and topological polar surface area (TPSA), and absence of any toxicity. Based on target intersection, 50 target genes were found and subjected to protein-protein interaction (PPI), gene ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. Four target genes were found to be involved in the breast cancer pathway. Consequently, molecular docking was utilised to analyse the molecular interactions between the compounds and four target protein receptors. Compound 211 exhibited the highest binding affinities for the epidermal growth factor receptor (EGFR), fibroblast growth factor receptor 1 (FGFR1), oestrogen receptor (ESR1), and cyclin dependent kinase 6 (CDK6) with values of −8.95 kcal/mol, −8.60 kcal/mol, −10.33 kcal/mol, and −9.90 kcal/mol, respectively. During MD simulation, compound 211 and its respective proteins were stable, compact, and had minimal flexibility. The findings provide foundations for future studies into the interaction underlying the anti-breast cancer potential of compounds with chalcone-based scaffold structures. Communicated by Ramaswamy H. Sarma

Molecular features of gastrointestinal stromal tumors “wild-type” (<i>KIT/PDGFRA</i> WT)

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. Their main features are the expression of CD117 (KIT) and mutations of KIT or PDGFRA in 85 % of patients. however, 10–15 % of adult GIST and 85 % of pediatric GIST do not have KIT/PDGFRA mutations (KIT/PDGFRA WT GIST or “wild-type” GIST). The prognosis and clinical course of these tumors and GIST with KIT/PDGFRA mutations differ. “Wild-type” GIST are quite heterogeneous group of tumors in terms of clinical phenotype, genetic etiology, and molecular pathways. Gastrointestinal stromal tumors are divided into SDH-deficient and SDH-competent based on the succinate dehydrogenase (SDH) complex. SDH-deficient GIST occur predominantly in children and young patients with Carney–Stratakis syndrome and Carney triad; there are also sporadic tumors. More than half of SDH-deficient GIST contain mutations in SDHA, SDHB, SDHD or SDHC, while the rest are caused by hypermethylation of the SDHC promoter. SDH-competent “wild-type” GIST include tumors with BRAF, RAS, or NF1 mutations that activate the RAS-RAF-MAPK pathway and KIT/PDGFRA/SDH/RAS-P WT GIST subtype or “quadruple wild type” GIST. The genomic profiles of these tumors and GIST with KIT/PDGFRA mutation or SDH deficiency differ significantly. One of the features of “quadruple wild type” GIST is activation of the FGFR (fibroblast growth factor receptors) signaling pathway due to chimeric FGFR, FGFR mutations, or overexpression of FGF (fibroblast growth factor). Another feature is chimeric genes containing fragments of NTRK, BRAF, FGFR and other genes that behave as oncogene drivers. In “quadruple wild-type” GIST the somatic mutations in TP53, MAX, MEN1, CTNND2, CHD4, ARIDIA and other genes were revealed as well as in the cell cycle genes RB1, CDK4, CDKN1B. There is no specific treatment for patients with “wild-type” GIST; the choice of drug is determined by the genetic disorder. There is a need to improve our understanding of the molecular mechanisms underlying the different GIST subtypes to develop more effective therapeutic approaches.

Durable response from fibroblast growth factor receptor inhibition in intrahepatic cholangiocarcinoma terminated by metachronous acute myeloid leukemia: a case report

IntroductionAdvances in the treatment of biliary tract cancer have been made possible through gains in genomic and epigenetic tumor understanding. The use of fibroblast growth factor receptor inhibitor has enabled significant clinical improvement in a specific group of patients with intrahepatic cholangiocarcinoma, some of whom with very durable responses.Case presentationWe present the case of a 69-year-old Caucasian patient with advanced intrahepatic cholangiocarcinoma who received the therapy with selective oral inhibitor of fibroblast growth factor receptor 1, 2, and 3 pemigatinib after multiple previous chemotherapies. This resulted in a durable stable disease condition for 15 months with good tolerability. The diagnosis of acute myeloid leukemia was an unanticipated serious adverse event, in which the impact of fibroblast growth factor receptor inhibition could not yet be determined due to inadequate data.ConclusionsIt is still possible to achieve durable tumor response in advanced previously treated intrahepatic cholangiocarcinoma through targeted therapies. The prolonged progression free survival means that there could be an increased risk of secondary malignancy in this patient group, which necessitates diagnostic and therapeutic strategies.

FGFs function in regulating myoblasts differentiation in spotted sea bass (Lateolabrax maculatus)

Fibroblast growth factors (FGFs) are a family of structurally related peptides that regulate processes such as cell proliferation, differentiation, and damage repair. In our previous study, fibroblast growth factor receptor 4 (fgfr4) was detected in the most significant quantitative trait loci (QTL), when identified of QTLs and genetic markers for growth-related traits in spotted sea bass. However, knowledge of the function of fgfr4 is lacking, even the legends to activate the receptor is unknown in fish. To remedy this problem, in the present study, a total of 33 fgfs were identified from the genomic and transcriptomic databases of spotted sea bass, of which 10 were expressed in the myoblasts. According to the expression pattern during myoblasts proliferation and differentiation, fgf6a, fgf6b and fgf18 were selected for further prokaryotic expression and purification. The recombinant proteins FGF6a, FGF6b and FGF18 were found to inhibit myoblast differentiation. Overall, our results provide a theoretical basis for the molecular mechanisms of growth regulation in economic fish such as spotted sea bass.

Case Report: Thanatophoric dysplasia

Thanatophoric dysplasia (TD) is a rare and lethal skeletal dysplasia caused by a de novo mutation in the fibroblast growth factor receptor 3 gene (FGFR3), with a frequency range of 1 in 20,000 to 50,000. We report a case of a 19-year-old primigravida from rural Nepal who presented with ultrasonographic findings suggestive of TD at 26 weeks and three days of gestation. The pregnancy was terminated due to the lethal nature of the condition. Accurate prenatal diagnosis and comprehensive counselling are paramount for families affected by this condition. This case has been reported due to its rarity, with the aim of raising awareness among healthcare professionals about this devastating condition.

Comparative transcriptomic analyses of brain-liver-muscle in channel catfish (Ictalurus punctatus) with differential growth rate

Growth is an important economically trait for aquatic animals. The popularity of farmed channel catfish (Ictalurus punctatus) in China has recently surged, prompting a need for research into the genetic mechanisms that drive growth and development to expedite the selection of fast-growing variants. In this study, the brain, liver and muscle transcriptomes of channel catfish between fast-growing and slow-growing groups were analyzed using RNA-Seq. Totally, 63, 110 and 86 differentially expressed genes (DEGs) were from brain, liver and muscle tissues. DEGs are primarily involved in growth, development, metabolism and immunity, which are related to the growth regulation of channel catfish, such as growth hormone receptor b (ghrb), fibroblast growth factor receptor 4 (fgfr4), bone morphogenetic protein 1a (bmp1a), insulin-like growth factor 2a (igf2a), collagen, type I, alpha 1a (col1a1a), acyl-CoA synthetase long chain family member 2 (acsl2) and caveolin 1 (cav1). This study advances our knowledge of the genetic mechanisms accounting for differences in growth rate and offers crucial gene resources for future growth-related molecular breeding programs in channel catfish.

Molecular Basis of Tumorigenesis of Bladder Cancer and Emerging Concepts in Developing Therapeutic Targets.

Advanced urothelial carcinoma (UC) is an aggressive disease whose mutagenic processes are yet to be elucidated. Targeted therapies are urgently needed, but the road from bench to bedside is slowly progressing. In this review, we discuss urothelial carcinoma etiology, along with the most recent advances in UC candidate targeted therapies. A comprehensive database search was performed. We aimed to review the most recent updates on UC genomics and targeted therapies. Pre-clinical as well as clinical studies were included. Our review highlights the advances in understanding the molecular basis of urothelial tumorigenesis, including smoking, chemical parasitic carcinogens, inheritance, and APOBEC3 editing enzymes. We discussed how these factors contributed to the current mutational landscape of UC. Therapeutic options for UC are still very limited. However, several promising therapeutic approaches are in development to leverage our knowledge of molecular targets, such as targeting fibroblast growth factor receptors (FGFR), DNA damage repair pathways, and HER2. Blindly testing targeted therapies based on other cancer data is not sufficient. UC-specific biomarkers are needed to precisely use the appropriate drug for the appropriate population. More efforts to understand UC biology and evolution are urgently needed.

Identification of potential drug molecules against fibroblast growth factor receptor 3 (FGFR3) by multi-stage computational-biophysics correlate

The fibroblast growth factor receptor 3 (FGFR3) is warranted as a promising therapeutic target in bladder cancer as it is described in 75% of papillary bladder tumors. Considering this, the present study was conducted to use different approaches of computer-aided drug discovery (CADD) to identify the best binding compounds against the active pocket of FGFR3. Compared to control pyrimidine derivative, the study identified three promising lead structures; BDC_24037121, BDC_21200852, and BDC_21206757 with binding energy value of −14.80 kcal/mol, −12.22 kcal/mol, and −11.67 kcal/mol, respectively. The control molecule binding energy score was −9.85 kcal/mol. The compounds achieved deep pocket binding and produced balanced interactions of hydrogen bonds and van der Waals. The FGFR3 enzyme residues such as Leu478, Lys508, Glu556, Asn562, Asn622, and Asp635. The molecular dynamic (MD) simulation studies additionally validated the docked conformation stability with respect to FGFR3 with a mean root mean square deviation (RMSD) value of < 3 Å. The root mean square fluctuation (RMSF) complements the complexes structural stability and the residues showed less fluctuation in the presence of compounds. The Poisson–Boltzmann or generalized Born and surface area continuum solvation (MM/PBSA and MM/GBSA) methods revalidated compounds better binding and highlighted van der Waals energy to dominate the overall net energy. The docked stability was additionally confirmed by WaterSwap and AMBER normal mode entropy energy analyses. In a nutshell, the compounds shortlisted in this study are promising in term of theoretical binding affinity for FGFR3 but experimental validation is needed.Communicated by Ramaswamy H. Sarma

Combined achondroplasia and short stature homeobox-containing (SHOX) gene deletion in a Danish infant

Short stature or shortening of the limbs can be the result of a variety of genetic variants. Achondroplasia is the most common cause of disproportionate short stature and is caused by pathogenic variants in the fibroblast growth factor receptor 3 gene (FGFR3).Short stature homeobox (SHOX) deficiency is caused by loss or defects of the SHOX gene or its enhancer region. It is associated with a spectrum of phenotypes ranging from normal stature to Léri-Weill dyschondrosteosis characterized by mesomelia and short stature or the more severe Langer mesomelic dysplasia in case of biallelic SHOX deficiency.Little is known about the interactions and phenotypic consequences of achondroplasia in combination with SHOX deficiency, as the literature on this subject is scarce, and no genetically confirmed clinical reports exist. We present the clinical findings in an infant girl with concurrent achondroplasia and SHOX deficiency. We conclude that the clinical findings in infancy are phenotypically compatible with achondroplasia, with no features of the SHOX deficiency evident. This may change over time, as some features of SHOX deficiency only become evident later in life.

Chronic Iodine Intake Excess Damages the Structure of Articular Cartilage and Epiphyseal Growth Plate.

This study aimed to explore the influence of excess iodine on the articular cartilage and epiphyseal growth plate in rats. Wistar rats (n = 200) were randomly divided into five groups with 40 rats in each: normal iodine (NI), 5-fold high iodine group (5HI), 10-fold high iodine group (10HI), 50-fold high iodine group (50HI), and 100-fold high iodine group (100HI). The rats were executed in 6 and 12months. 24-h urinary iodine concentration (UIC) was monitored by arsenic-cerium catalytic spectrophotometry. The chemiluminescence method was used to determine the thyroid function. The pathological changes in the epiphyseal plate, articular cartilage, and thickness of the epiphyseal plate were observed. The mRNA expression of collagen II (ColII), collagen X, matrix metalloproteinase-13 (MMP-13), and fibroblast growth factor receptor 1 in articular chondrocytes was detected by RT-PCR. 24-h UIC increased as iodine intake increased. In the 12th month, there was a significant increase in serum sTSH and a decrease in serum FT4 in HI groups, compared to the NI group. There was a decrease in the number of proliferating cells in the epiphyseal plate and an increase in the number of mast cell layers. The chondrocytes appeared disorganized, and the tidal lines were disturbed or even broken. Growth plate thickness decreased with increasing iodine intake. Compared with the NI group, ColII and MMP-13 mRNA expression in chondrocytes in all HI groups significantly increased. Chronic iodine overdose increases the risk of hypothyroidism. Chronic iodine overdose leads to abnormal morphology of epiphyseal growth plates and articular cartilage, increasing the risk of osteoarthritis.

Derazantinib Inhibits the Bioactivity of Keloid Fibroblasts via FGFR Signaling.

Keloids are common benign cutaneous pathological fibrous proliferation diseases, which are difficult to cure and easily recur. Studies have shown that fibroblast growth factor receptor-1 (FGFR1) was enhanced in pathological fibrous proliferation diseases, such as cirrhosis and idiopathic pulmonary fibrosis (IPF), suggesting the FGFR1 pathway has potential for keloid treatment. Derazantinib is a selective FGFR inhibitor with antiproliferative activity in in vitro and in vivo models. The present study determined the effects of derazantinib on human keloid fibroblasts (KFs). Cell viability assay, migration assay, invasion assay, immunofluorescence staining, quantitative polymerase chain reaction, Western blot analysis, HE staining, Masson staining, and immunohistochemical analysis were used to analyze the KFs and keloid xenografts. In this study, we found that derazantinib inhibited the proliferation, migration, invasion, and collagen production of KFs in vitro. The transcription and expression of plasminogen activator inhibitor-1 (PAI-1), which is closely related to collagen deposition and tissue fibrosis, was significantly inhibited. Also, derazantinib inhibited the expression of FGFR1 and PAI-1 and reduced the weight of the implanted keloid from the xenograft mice model. These findings suggest that derazantinib may be a potent therapy for keloids via FGFR signaling.

Suppression of BMP signaling restores mitral cell development impaired by FGF signaling deficits in mouse olfactory bulb

Fibroblast growth factors (FGFs) and bone morphogenic proteins (BMPs) play various important roles in the development of the central nervous system. However, the roles of FGF and BMP signaling in the development of the olfactory bulb (OB) are largely unknown. In this study, we first showed the expression of FGF receptors (FGFRs) and BMP receptors (BMPRs) in OB RGCs, radial glial cells (RGCs) in the developing OB, which generate the OB projection neurons, mitral and tufted cells. When the FGF signaling was inhibited by a dominant-negative form of FGFR1 (dnFGFR1), OB RGCs accelerated their state transition to mitral cell precursors without affecting their transcription cascade and fate. However, the mitral cell precursors could not radially migrate to form the mitral cell layer (MCL). In addition, FGF signaling inhibition reduced the expression of a BMP antagonist, Noggin, in the developing OB. When BMP signaling was suppressed by the ectopic expression of Noggin or a dominant-negative form of BMPR1a (dnBMPR1a) in the developing OB, the defect in MCL formation caused by the dnFGFR1 was rescued. However, the dnBMPR1a did not rescue the accelerated state transition of OB RGCs. These results demonstrate that FGF signaling is important for OB RGCs to maintain their self-renewal state and MCL formation. Moreover, the suppression of BMP signaling is required for mitral cells to form the MCL. This study sheds new light on the roles of FGFs and BMPs in OB development.

From nature to cancer therapy: Evaluating the Streptomyces clavuligerus secondary metabolites for potential protein kinase inhibitors.

The study aimed to evaluate the antioxidant, protein kinase inhibitory (PKIs) potential, cytotoxicity activity of Streptomyces clavuligerus extract. DPPH assay revealed a robust free radical scavenging capacity (IC50 28.90 ± 0.24 µg/mL) of organic extract with a maximum inhibition percentage of 61 ± 1.04%. PKIsassay revealed the formation of a whitish bald zone by S. clavuligerus extracts which indicates the presence of PKIs. The cytotoxicity activity of organic fraction of extract through Sulforhodamine B assay on MCF-7, Hop-62, SiHa, and PC-3 cell lines demonstrated the lowest GI50 value against the MCF-7 cell line followed by the PC-3 cell line, showing potent growth inhibitory potential against human breast cancer and human prostate cancer cell line. HR-LCMS analysis identified multiple secondary metabolites from the organic and aqueous extracts of S. clavuligerus when incubated at 30°C under 200 rpm for 3 days. All the secondary metabolites were elucidated for their potential to inhibit RTKs by molecular docking, molecular dynamic simulation, MM/GBSA calculations, and free energy approach. It revealed the superior inhibitory potential of epirubicin (Epi) and dodecaprenyl phosphate-galacturonic acid (DPGA) against fibroblast growth factors receptor (FGFR). Epi also exhibited excellent inhibitory activity against the platelet-derived growth factor receptor (PDGFR), while DPGA effectively inhibited the vascular endothelial growth factor receptor.Additionally, the presence Epiin S. clavuligerus extract was validated through the HPLC technique. Thus, our findings highlight a superior inhibitory potential of Epiagainst FGFR and PDGFR RTKs than the FDA-approved drug.

FGF19/FGFR4 signaling contributes to hepatocellular carcinoma survival and immune escape by regulating IGF2BP1-mediated expression of PD-L1

Immune-checkpoint blockade (ICB) therapies have been widely used in clinical treatment of cancer patients, but only 20–30% of patients benefit from immunotherapy. Therefore, it is important to decipher the molecular mechanism of resistance to ICB and develop new combined treatment strategies. PD-L1 up-regulation in tumor cells contributes to the occurrence of immune escape. Increasing evidence shows that its transcription level is affected by multiple factors, which limits the objective response rate of ICB. Fibroblast growth factor 19 (FGF19), a member of the fibroblast growth factor family, is widely involved in the malignant progression of many tumors by binding to fibroblast growth factor receptor 4 (FGFR4). In this study, we confirmed that FGF19 acts as a driver gene in hepatocellular carcinoma (HCC) progression by binding to FGFR4. The up-regulation of FGF19 and FGFR4 in HCC is associated with poor prognosis. We found that FGF19/FGFR4 promoted the proliferation and invasion of HCC cells by driving IGF2BP1 to promote PD-L1 expression. Knockdown of FGFR4 significantly reduced the expression of IGF2BP1/PD-L1 and inhibited the proliferation and invasion of HCC cells. These biological effects are achieved by inhibiting the PI3K/AKT pathway. The combination of FGFR4 knockdown and anti-PD-1 antibody greatly suppressed tumor growth and enhanced the sensitivity of immunotherapy, highlighting the clinical significance of FGF19/FGFR4 activation in immunotherapy.

In vitro and in vivo pharmacokinetics, disposition, and drug-drug interaction potential of tinengotinib (TT-00420), a promising investigational drug for treatment of cholangiocarcinoma and other solid tumors

Early-stage clinical evaluation of tinengotinib (TT-00420) demonstrated encouraging preliminary efficacies in multiple types of refractory cancers, including fibroblast growth factor receptors (FGFR) inhibitors relapsed cholangiocarcinoma (CCA), castrate-resistant prostate cancer (CRPC), and HR+/HER2- breast cancer and triple negative breast cancer (TNBC). To further evaluate drug-like properties of the drug candidate, it is imperative to understand its metabolism and pharmacokinetic properties. This manuscript presented the investigation results of in vitro permeability, plasma protein binding, metabolic stability, metabolite identification, and drug-drug interaction of tinengotinib. Preclinical ADME (absorption, distribution, excretion, and metabolism) studies in rats and dogs was also conducted using a radioactive labeled tinengotinib, [14C]tinengotinib. Tinengotinib was found to have high permeability and high plasma protein binding and equally distributed between blood and plasma. There were no unique metabolites in human liver microsomes and tinengotinib showed moderate hepatic clearance. Tinengotinib is neither a potential inhibitor nor an inducer of P450 enzymes at clinically relevant concentrations, and unlikely to cause drug-drug interactions when used in combination with other drugs mediated by a key transporter, either as victim or perpetrator. Taken together, tinengotinib demonstrated a minimal risk of clinically relevant drug-drug interactions. Tinengotinib showed good oral bioavailability and dose-dependent exposures in both rat and dog after oral administration. The total radioactivity was largely distributed in the gastrointestinal system and liver, and tinengotinib could not easily pass through the blood-brain barrier. The major drug-related component in rat and dog plasma was unchanged drug (>89 %) with primary route of elimination via feces (>93 % of the dose) and minor via renal excretion (<4 % of the dose). Tinengotinib metabolism is mediated largely by CYP3A4, with minor contributions from CYP2D6 and CYP2C8. Major metabolic pathways include oxidation, oxidative cleavage of the morpholine ring, glucuronide and glutathione conjugations. The overall preclinical pharmacokinetics profile supported the selection and development of tinengotinib as a clinical candidate.

Abstract A165: FGFR alterations in pediatric cancers: Opportunity for targeted therapy

Abstract Introduction: The Fibroblast Growth Factor Receptor (FGFR) family consists of four members, FGFR1–4, and is involved in regulating cell proliferation, survival, and differentiation. FGFR alterations, such as fusions, mutations and amplification, have been found in multiple adult cancers, for which several FGFR inhibitors are in clinical development. Although cancer is a leading cause of death in children, the understanding of genetic causes of pediatric cancers is urgently lacking and the progress in developing targeted therapy in children significantly lags that in adults. This study aimed to uncover the FGFR alterations in pediatric cancers and provide preclinical rationale for FGFR inhibitors as potential therapy in children with cancer. Methods: The prevalence of FGFR alterations in pediatric cancers such as neuroblastoma (NB) , gliomas and sarcomas was calculated based on systematic queries of multiple cancer databases that house real-world molecular profiling data. A pan-FGFR inhibitor, BGJ398, was used as a tool compound for FGFR inhibition. Effect of BGJ398 on cell proliferation was tested by Incucyte in a panel of 12 NB cell lines. Cell migration, survival and signaling pathway modulation were carried out in a subset of NB lines. Results: The overall rates of genomic alterations (fusions, mutations and amplification) of FGFR1, 2, 3 and 4 in pediatric cancers are 0.5%, 0.1%, 1.1% and 0.8%, respectively, with pediatric gliomas exhibiting higher rates in all subtypes. Although FGFR genomic alterations are rare (&amp;lt;0.1%) in neuroblastoma and rhabdoid sarcoma, overexpression of FGFR1-4 is observed in subsets of these tumors. In pediatric glioma, FGFR1, 2, 3 and 4 alterations are found in 1%, 1.6%, 2.1% and 0.9% tumor samples, respectively, and the mutation profile substantially differs from that of adult glioma. Dose-dependent inhibition of cell proliferation and migration, as well as induction of cell death, were achieved with BGJ398 treatment in a panel of NB cells, accompanied by inhibition of MAPK pathway and induction of apoptosis. Conclusions: Adult and pediatric cancers share common mechanisms of FGFR activation, but differ in overall alteration rates and in relative abundance of specific aberrations. Preliminary preclinical data indicates the therapeutic potential of FGFR inhibitors in the treatment of certain pediatric cancers. Citation Format: Ivan Li, Yuchen Huo, Gary Li, Peter Zage. FGFR alterations in pediatric cancers: Opportunity for targeted therapy [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A165.

Does subtyping of high-grade pulmonary neuroendocrine carcinomas have an impact on therapy selection?

Small cell lung cancer (SCLC) and large cell neuroendocrine carcinomas (LCNEC) are characterized by a rapid progressive course. Therapy for SCLC has not much changed for decades, and in LCNEC controversies exist, favoring either SCLC-like or non-small cell lung cancer (NSCLC)-like therapy. Three subtypes of SCLC identified in cell cultures, namely ASCL1, NeuroD1, and POU2F3 have been confirmed by immunohistochemistry. The fourth type based on the expression of YAP1 was questioned, and another type, inflamed SCLC, was proposed. SCLC and LCNEC samples were investigated by immunohistochemistry for different subtypes. Additionally, immunohistochemical markers as potential tools to identify patients who might respond to targeted treatment were investigated. For validation a biopsy set was added. ASCL1, NeuroD1, and POU2F3 were expressed in different percentages in SCLC and LCNEC. Similar percentages of expression were found in biopsies. ATOH was expressed in combination with one of the subtypes. YAP1 and TAZ were expressed in some SCLC and LCNEC cases. HES1 expression was seen in few cases. Predominantly stroma cells expressed programmed cell death ligand 1 (PD-L1). The dominant MYC protein was N-MYC. Aurora kinase A (AURKA) was expressed in the majority of both carcinomas, whereas fibroblast growth factor receptor 2 (FGFR2) in few. SCLC and LCNEC can be subtyped into ASCL1-, NeuroD1-, and POU2F3-positive types. AURKA expression and positivity for N-MYC protein was not associated with subtypes. AURKA and FGFR2 are both possible targets for inhibition in SCLC and LCNEC, but patients' selection should be based on expression of the enzyme. Combined chemo- and immunotherapy might be decided by PD-L1 staining of stroma cells.

Abstract LB_B04: Deciphering FGFR3-TACC3 oncogenic fusions

Abstract Chromosomal rearrangements of the fibroblast growth factor receptor (FGFR) genes that give rise to fusions are one of several mechanisms by which the FGF/FGFR signaling axis can become deregulated and result in enhanced signaling in cancer. We have previously identified truncation of exon (E) 18 of FGFR2 as a potent single-driver alteration in cancer, independently of the rearrangement (RE) partner. In contrast, the same does not appear to hold true for its E18-truncated ortholog FGFR3. We mined human oncogenomic datasets from Hartwig Medical Foundation (&amp;gt;2,500 WGS profiles) and Foundation Medicine (&amp;gt;200,000 hybrid-capture panel-seq profiles) for alterations affecting FGFR3. Examination of the structural variants affecting FGFR3 uncovered that 85% of all E18-truncating FGFR3 REs involved transforming acidic coiled-coil-containing protein 3 (TACC3) as the downstream fusion partner gene, while REs with intergenic regions and other known protein-encoding genes were much less frequent. Additionally, there was a clear predominance of self-interacting domains (95%) among all FGFR3 RE partners, with the coiled-coil domain being the most recurrent, suggesting enhanced receptor dimerization and downstream signaling capacity for the majority of the FGFR3 fusions. Our findings led to the generation of a compendium of FGFR3 structural variants which we then functionally tested. In vitro testing of mouse mammary epithelial cells expressing Fgfr3ΔE18-Tacc3E7-E16 fusion variants showed that both E18-truncation and a fusion partner were required for 3D outgrowth and signaling induction. In vivo evaluation of the oncogenic capacity of Fgfr3 variants using somatic delivery of lentiviruses to the mouse mammary gland via intraductal injection and lung via intratracheal injection found that Fgfr3ΔE18-Tacc3E7-E16 fusion variants rapidly induced mammary and lung tumor formation in wild-type and Wap-Cre;Cdh1F/F, and in wild-type and Trp53F/F mice, respectively. In contrast, Fgfr3full-length(FL), Fgfr3ΔE18 and Fgfr3FL–Tacc3E7-E16 were non-tumorigenic. Noteworthy, mammary tumors driven by Fgfr3ΔE18-Tacc3E7-E16 fusions were sensitive to the FGFR inhibitor AZD4547 during a drug intervention study. In summary, our findings show that E18-truncating FGFR3 alterations are recurrent across human cancers and, as opposed to FGFR2 E18-truncating alterations, FGFR3 appears to depend both on E18-truncation and an additional fusion partner with dimerizing capacity. Notably, TACC3 is the most recurrent 3’ fusion partner across all FGFR3 E18-truncating alterations, and somatic tumor modeling has shown that Fgfr3ΔE18-Tacc3 fusions drive mouse mammary and lung tumorigenesis, and are sensitive to FGFR targeted therapy. Citation Format: Julia Yemelyanenko, Jinhyuk Bhin, Sjoerd Klarenbeek, Ji-Ying Song, Catrin Lutz, Marieke van de Ven, Shridar Ganesan, Lodewyk F. A. Wessels, Daniel Zingg, Jos Jonkers. Deciphering FGFR3-TACC3 oncogenic fusions [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_B04.

Discovery and development of quinazoline compounds as irreversible pan-fibroblast growth factor receptor inhibitors with potent antitumor activities

Abnormal activation of fibroblast growth factor receptors (FGFRs) results in the development and progression of multiple cancer types. Therefore, it is an attractive target for tumor therapy, and many efforts have been directed to the discovery of irreversible FGFR inhibitors over the last decade. Using a quinazoline scaffold, we used structure-based drug design to obtain a series of novel covalent pan-FGFR inhibitors. One of the representative compounds, I-11, showed remarkable enzymatic activity toward FGFR1–4 (FGFR1/2/3/4, IC50 = 5.6/2.2/8.5/4.6 nM) and strongly suppressed the proliferation of Huh7 HCC cells (IC50 = 6.35 nM). Further, I-11 exhibited reasonable PK profiles (F = 57.5 %) and showed significant antitumor effects in the Huh-7 xenograft model without obvious changes in body weight. Overall, I-11 was identified as a potential pan-FGFR inhibitor for cancer therapy and deserved further research.

Heparin-binding epidermal growth factor and fibroblast growth factor 2 rescue Müller glia-derived progenitor cell formation in microglia- and macrophage-ablated chick retinas.

Recent studies have demonstrated the impact of pro-inflammatory signaling and reactive microglia/macrophages on the formation of Müller glial-derived progenitor cells (MGPCs) in the retina. In chick retina, ablation of microglia/macrophages prevents the formation of MGPCs. Analyses of single-cell RNA-sequencing chick retinal libraries revealed that quiescent and activated microglia/macrophages have a significant impact upon the transcriptomic profile of Müller glia (MG). In damaged monocyte-depleted retinas, MG fail to upregulate genes related to different cell signaling pathways, including those related to Wnt, heparin-binding epidermal growth factor (HBEGF), fibroblast growth factor (FGF) and retinoic acid receptors. Inhibition of GSK3β, to simulate Wnt signaling, failed to rescue the deficit in MGPC formation, whereas application of HBEGF or FGF2 completely rescued the formation of MGPCs in monocyte-depleted retinas. Inhibition of Smad3 or activation of retinoic acid receptors partially rescued the formation of MGPCs in monocyte-depleted retinas. We conclude that signals produced by reactive microglia/macrophages in damaged retinas stimulate MG to upregulate cell signaling through HBEGF, FGF and retinoic acid, and downregulate signaling through TGFβ/Smad3 to promote the reprogramming of MG into proliferating MGPCs.