Growth Factor Receptor Function Research Articles

Determination of FGFR1 Functions in Cytarabine Treatment of Acute Myeloid Leukemia Through Bioinformatics Analysis

Aim: Among the most prevalent subtypes of acute leukemia is acute myeloid leukemia (LAML). Consequently, it is essential to understand the molecular causes of LAML and find its predictive and diagnostic biomarkers. The aim of this study is to determine the molecular functions of fibroblast growth factor receptor 1(FGFR1) involved in LAML pathogenesis and its potential therapeutic effect for AML treatment. Methods: The molecular docking interaction of the Cytarabine with its target FGFR1 was examined. The Gene Expression Profiling Interactive Analysis, version 2 (GEPIA2), and UALCAN tools database were used to obtain the LAML gene expression datasets. Gene functional annotation was performed to investigate the DEGs' possible role. Using the Interactive Gene database retrieval tool (STRING) and a few chosen hub modules from the GeneMANIA database, the protein- protein interaction (PPI) network were constructed. A survival analysis was performed on the effects of hub genes on the overall survival of LAML patients. Results: As a result of docking, a strong interaction was observed between cytarabine and FGFR1. It has been discovered that cytarabine can reverse FGFR1 expression. The survival study results showed an association between the prognosis of AML patients and one of the central genes, FGFR1. Conclusion: The expression profile and functions of FGFR1 were determined in LAML patients. It has been shown that FGFR1 can be a viable therapeutic target for LAML and a possible biomarker for diagnosis.

Abstract 1510: Cell-cell contacts regulate HER2 cellular localization and the transitions between migration and proliferation in breast cancer cells

Abstract Introduction: Epithelial-to-mesenchymal transition (EMT) is widely recognized as the primary mechanism regulating invasion and metastatic dissemination in carcinomas. In contrast, the mechanisms triggering single disseminated cancer cells (DCC) to reacquire their epithelial identity at ectopic sites, initiating metastasis formation, remain unclear. Since we had previously noted that HER2 expression levels and cellular density impact on migration and proliferation, we sought to determine whether they are involved in molecular mechanisms regulating transitions between proliferation and migration. Methods: To control HER2 expression levels we generated inducible cell models. Cell density was assessed by the number of cell-cell contacts or by the number of cells per area. Pathway analyses were performed by gene expression analysis, protein interactions by western blotting and mass spectrometry. Migration and proliferation were analyzed by functional assays including in vitro live cell imaging. Results: Migrating epithelial cells undergo reduced protein trafficking, resulting in a perinuclear deposition of HER2. This was accompanied by increased calcium ion regulation via phospholipase-C in the endoplasmic reticulum (ER). Upon the establishment of cell-cell contacts, particularly between cells expressing desmosome cadherin proteins, HER2 is redirected to the cell surface through direct physical binding with desmoplakin, facilitating proliferation signals. Then, PIP2 to PIP3 is converted through the activation of the PI3K pathway, concomitant with the upregulation of PDPK1. The PH domain of PDPK1 exhibits a high binding affinity to PIP2 molecules. Consequently, membrane localization of HER2 significantly diminishes PIP2 availability for the PLC pathway, redirecting cells towards proliferation. Patient sample analysis confirmed the loss of membrane-bound HER2 in solitary circulating tumor cells (CTCs), which was paralleled by increased plakoglobin, elevated ZEB1, and reduced KI67 protein levels. Conclusion: Cell-cell contacts determine the cellular localization and function of growth factor receptors like HER2. Single disseminating cancer cells therefore need to establish such contacts at metastatic sites to activate proliferation programs. Our data are in line with findings that circulating tumor cell clusters are associated with higher metastatic rates, the impact of specific metastatic niches for outgrowth and have implementation for the targeting of single DCC. Citation Format: Hedayatollah Hosseini, Saba Sameri, Shabnam Shahrivari, Carolina Fisch, Miriam Kokal, Michael Schletter, Paul Sylvester Hahn, Lisa Seider, Marisa Schübel, Durdam Das, Martin Hoffmann, Christian Werno, Kathrin Weidele, Vladan Milosevic, Arne Östman, Shamim Sarhadi, Joachim Wegener, Stefanie Michaelis, Florian Weber, Astrid Bruckmann, Ernst R. Tamm, Yuting Li, Christoph A. Klein. Cell-cell contacts regulate HER2 cellular localization and the transitions between migration and proliferation in breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1510.

Progress on the EGFR pathway drives targeted therapy for NSCLC

Epidermal growth factor receptor (EGFR) is a key tyrosine kinase receptor that regulates cell survival, proliferation, division, and differentiation. The mutation of the EGFR gene is one of the most common gene mutations responsible for non-small cell lung cancer (NSCLC). Extensive research has been done in the field. Several key EGFR signaling pathways control cell activity, such as MAPK/EPK, PI3K/Akt/mTOR, and JAK/STAT pathways. Mutation of EGFR can cause abnormal activation of signaling cascades, leading to constant cell growth and division, eventually causing tumor growth. Understanding the function of epidermal growth factor receptor and EGFR signaling pathways contributes to the development of targeted treatment for lung cancer. Therefore, through recent research and analysis on the mechanism of action and related pathways of EGFR, this article finds that EGFR tyrosine kinase inhibitor (TKI), a commonly used drug to treat lung cancer, is one of the most effective treatment and it has high potential. However, resistance to TKIs caused by secondary mutations has become a crucial challenge. Novel generations of TKI and combination therapies are needed.

Detection of the de novo Pro253Arg Mutation of Fibroblast Growth Factor Receptor 2 (FGFR2) in a Pediatric Patient with Congenital Hand Anomaly

Congenital hand deformities are a group of birth defects related to abnormal development of soft, cartilage, or bone tissues in the hands. Recent studies have indicated that the most usual reason of congenital hand anomalies are due to the genetic factors. In this study, we sequenced the exome of a 2.5-year-old female patient case with bilateral hand deformity. Results revealed that the patient did not carry mutations in the expression region of the GLI3 and SHH genes. However, the patient did have a heterozygous mutation: FGFR2: c.C758G, p.P253R. Sanger sequencing confirmed this was a de novo mutation as it was not detected in the parents. In silico analyses indicated that P253R has a potential effect to alter the structure and function of the fibroblast growth factor receptor, consequently disrupting the processes involved in the formation and development of bone and cartilage tissues. Overall, this research will contribute to a better understanding of the role and functionality of the FGF molecular signaling network in the development and synthesis of bone and cartilage tissues, particularly during the embryonic stage.

Spectroscopic Characterization, Quantum Chemical, Molecular Docking, Antibacterial and Anticancer Studies on Ethyl Coumarin-3-Carboxylate: an Antibacterial and Lung Cancer Agent

The detailed theoretical and experimental (FT-IR, FT-Raman, UV-visible) spectroscopy analyses of the Ethyl Coumarin-3-Carboxylate (ECC) molecule were carried out. The ECC compound’s pharmacological properties were also investigated, utilizing antibacterial and anticancer activity investigations. Initially, the ECC molecule was optimized by the density functional theory B3LYP method with a 6-311 G++ (d,p) basis set using the Gaussian 09 W program. The optimized molecular structure provides the harmonic vibrational frequencies of the ECC molecule. The observed and computed vibrational wavenumbers were assigned and found to be well correlated. UV-Vis absorption spectrum analysis indicates that the molecule contains π →π* and n → π* electronic transitions. The Frontier molecular orbital analysis confirmed the molecular reactivity and bioactivity of ECC, while the Mulliken atomic charge distribution analysis pinpointed the molecule’s reactive sites. Antibacterial testing demonstrated the ECC compound’s inhibitory effect on various bacterial strains, with a particular impact on Klebsiella pneumonia. In vitro, anticancer assessments showcased ECC's stronger inhibitory effects on A549 lung cancer cell lines compared to HeLa cervical cancer cell lines. Additionally, in silico molecular docking investigations provided further validation that the ECC compound can inhibit the function of the epidermal growth factor receptor, a factor associated with lung cancer. As a result, this study lays the foundation for the development of novel drugs for lung cancer treatment.

Defective cathepsin Z affects EGFR expression and causes autosomal dominant palmoplantar keratoderma.

The abnormal function of epidermal growth factor receptor (EGFR) has recently been shown to underlie various disorders of cornification. To delineate the genetic basis of a novel dominant form of palmoplantar keratoderma (PPK). Whole-exome (WES) and direct sequencing, quantitative real-time polymerase chain reaction, protein modelling, confocal immunofluorescence microscopy, immunoblotting, three-dimensional skin equivalents and an enzyme activity assay were used to delineate the genetic basis of a novel dominant form of PPK. WES revealed heterozygous variants (c.274T > C and c.305C > T) in CTSZ (encoding cathepsin Z) in four individuals (belonging to three unrelated families) with focal PPK. Bioinformatics and protein modelling predicted the variants to be pathogenic. Previous studies have suggested that EGFR expression may be subject to cathepsin regulation. Immunofluorescence revealed reduced cathepsin Z expression in the upper epidermal layers and concomitant increased epidermal EGFR expression in patients harbouring CTSZ variants. Accordingly, human keratinocytes transfected with constructs expressing PPK-causing variants in CTSZ displayed reduced cathepsin Z enzymatic activity, as well as increased EGFR expression. In line with the role played by EGFR in the regulation of keratinocyte proliferation, human keratinocytes transfected with the PPK-causing variants showed significantly increased proliferation that was abolished upon exposure to erlotinib, an EGFR inhibitor. Similarly, downregulation of CTSZ resulted in increased EGFR expression and increased proliferation in human keratinocytes, suggestive of a loss-of-function effect of the pathogenic variants. Finally, three-dimensional organotypic skin equivalents grown from CTSZ-downregulated cells showed increased epidermal thickness and EGFR expression as seen in patient skin; here, too, erlotinib was found to rescue the abnormal phenotype. Taken collectively, these observations attribute to cathepsin Z a hitherto unrecognized function in epidermal differentiation.

Synthesis and Characterization of 8-Amino-6-Methoxy Quinolinium 2,4-Dinitrophenolate: DFT, Molecular Docking, Antimicrobial, and In Vitro Cytotoxicity Evaluation Studies

Quinoline and its derivatives are well recognized for their anticancer activities and pharmacological properties. In this work, the compound 8-Amino-6-methoxyquinolinium 2,4-dinitrophenolate (8A6MQDNP) was synthesized and characterized using FT-IR, FT-Raman, and UV–Vis spectroscopic techniques. The optimized molecular structure, structural properties, and harmonic vibrational frequencies of the molecule were calculated using the DFT/B3LYP method with a cc-pVTZ basis set using the Gaussian 09 software. The observed and calculated vibrational wavenumbers were assigned and correlated well each other. The UV–Vis spectral analysis reveals the π to π* and n to π* electronic transitions of the molecule. The title molecule’s bioactivity is confirmed by frontier molecular orbital (FMOs) analysis; also the intramolecular charge transfer occurred from the quinoline ring to the dinitrophenol. Molecular electrostatic potential surface analysis verifies the FMOs results. The bioactivity of the molecule was confirmed by the natural bond orbital analysis. The Mulliken atomic charge distribution indicates the molecule’s chemical reactivity. Furthermore, the antibacterial results show that the 8A6MQDNP compound can inhibit the development of the tested bacterial strains, most notably the staphylococcus aureus bacterial strain. In vitro cytotoxicity test demonstrates that the 8A6MQDNP compound suppresses the development of A549 cancer cell lines more than HeLa cancer cell lines. Molecular docking investigation confirms that the title molecule inhibits the function of the epidermal growth factor receptor, which has been associated with lung cancer. As a result, the current study paves the way for the development of novel drugs for the treatment of lung cancer.

RETRACTED: Chitosan-alginate nanoparticles of cabazitaxel: Design, dual-receptor targeting and efficacy in lung cancer model

Cabazitaxel (CZT) loaded chitosan-alginate based (CSA) nanoparticles were developed with dual targeting functions of both folate receptor and epidermal growth factor receptor (EGFR) using ionic gelation technique. The chitosan-folate conjugate was synthesized, and characterized by using FTIR, NMR and Mass spectroscopy. The physicochemical parameters and morphology of all CSA nanoparticles were examined. The degree of conjugation of folic acid and cetuximab (CTXmab) was determined by UV–Visible spectroscopy and Bradford assay, respectively. Moreover, XPS analysis also supported the presence of the ligands on nanoparticles. The cellular-uptake study performed on A-549 cells demonstrated a significant enhancement in the uptake of dual-receptor targeted CSA nanoparticles than non-targeted and single-receptor targeted CSA nanoparticles. Further, CZT-loaded dual receptors targeted CSA nanoparticles also showed significantly lower IC50 values (~38 folds) than the CZT control against A-549 cells. Further, in-vivo histopathological evaluations of dual receptor-targeted CSA nanoparticles have demonstrated better safety in Wistar rats. Moreover, its treatment on the Benzo(a)pyrene (B(a)P) induced lung cancer mice model has showed the enhanced anticancer efficacy of CZT with a prolonged survival rate.

MiR-335 promotes corneal neovascularization by Targeting EGFR

BackgroundCorneal neovascularization (CRNV) is a severe threat to the vision of people. MicroRNA-335 (miR-335) has the function of facilitating angiogenesis. However, whether miR-335 regulates the progression of CRNV remains unclear.MethodsThe miR-335 expressions in CRNV rats induced by corneal suture and HUVECs induced by b-FGF were detected by quantitative real-time PCR. For the miR-335 function, wound healing and tube formation assays were performed. For the miR-335 mechanism, a dual-luciferase reporter gene assay was conducted. Besides, for the epidermal growth factor receptor (EGFR) function, Cell Counting Kit-8 and wound healing assays were performed. Meanwhile, the rescue assay was used to assess the miR-335/EGFR function in the migration and angiogenesis of b-FGF-treated HUVECs.ResultsFunctionally, the miR-335 knockdown weakened the migration and angiogenesis of b-FGF-treated HUVECs, while the miR-335 overexpression showed an opposite trend. Mechanistically, miR-335 interacted with EGFR and negatively regulated the expression of EGFR. The rescue assay illustrated that miR-335 regulated the migration and angiogenesis of b-FGF-treated HUVECs through EGFR.ConclusionsIn general, our data confirmed that miR-335 facilitated the process of CRNV by targeting EGFR.

CD82 palmitoylation site mutations at Cys5+Cys74 affect EGFR internalization and metabolism through recycling pathway.

Tetraspanin CD82 often participates in regulating the function of epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor (c-Met). Palmitoylation is a post-translational modification that contributes to tetraspanin web formation and affects tetraspanin-dependent cell signaling. However, the molecular mechanisms by which CD82 palmitoylation affects the localization and stability of EGFR and c-Met have not yet been elucidated. This study focuses on the expression and distribution of EGFR and c-Met in breast cancer as well as the related metabolic pathways and molecular mechanisms associated with different CD82 palmitoylation site mutations. The results show that CD82 with a palmitoylation mutation at Cys5+Cys74 can promote the internalization of EGFR. EGFR is internalized and strengthened by direct binding to CD82 with the tubulin assistance and located at the recycling endosome. After studying the recycling pathway marker proteins Rab11a and FIP2, we found that formation of the EGFR/CD82/Rab11a/FIP2 complex promotes the internalization and metabolism of EGFR through the recycling pathway and results in the re-expression of EGFR and CD82 on the cell membrane.

Tympanic membrane reconstruction of a persistent perforation associated with massive myringosclerosis in a girl with achondroplasia – case report

Achondroplasia is a genetic disease connected with improper function of fibroblast growth factor receptor 3 (FGFR3) resulting in musculoskeletal disorders. Apart from characteristic musculoskeletal abnormalities (short statute with short proximal limb segments, prominent forehead, midface hypoplasia and a depressed nasal bridge) and generalized hypotonia it also affects otolaryngological field in a form of sleep-related upper respiratory tract disorders (obstructive and central apnea) and conductive hearing loss. This is the result of anatomical phenotype, together with Eustachian tube dysfunction. Interestingly, up to 25% of children with achondroplasia may fail hearing screening in one or both ears. In most cases laryngological disorders require surgical procedures, usually adenotomy, adenotonsillectomy, tonsillectomy or tube placement. Such surgical interventions increase the risk of complications, especially when repeated. We would like to present a case of a girl with achondroplasia that was qualified for myringoplasty because of persistent tympanic membrane perforation due to surgical extrusion of persistent ventilation tube, with associated massive myryngoslerosis.

Physiological functions of keratinocyte epidermal growth factor receptors and their role in the development of skin toxicity during targeted cancer therapy

The binding of epidermal growth factor (EGFR) receptors is a good target for the treatment of lung, colon, pancreatic, head and neck cancers. The adverse events that develop as a result of therapy, in the form of lesions of the skin and mucous membranes, is a serious problem for the doctor to choose a long-term treatment strategy. The developing symptoms of skin toxicity, as skin problems in patients are often called, are worrisome and often affect the quality of life and compliance with the treatment regimen. Thus, it is important for doctors to know the prerequisites and ways to manage skin toxicity associated with the use of tyrosine kinase receptor inhibitors of epidermal growth factor.
 The mechanism and consequences of EGF receptor activation are described to explain the development of undesirable skin toxicity associated with inhibition of the epidermal growth factor receptor.

Ultrasound-Mediated Cavitation Enhances EGFR-Targeting PLGA-PEG Nano-Micelle Delivery for Triple-Negative Breast Cancer Treatment.

Simple SummaryTriple-negative breast cancer (TNBC) with negative expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2) is considered to be associated with poorer outcomes and a higher risk of recurrence or metastasis owing to a lack of effective targeted therapeutic drugs. The epidermal growth factor receptor (EGFR) functions is a driver of disease progression in most of TNBC that represents a viable target that can be leveraged to guide the intra-tumoral delivery of chemotherapeutic drugs in TNBC patients. Moreover, ultrasound-mediated cavitation (UMC) strategies increase tissue permeability and extravasation through nuclei-dependent cavitation via sonoporation, thus enabling drugs to better enter target tissues. In this research, a combination of active, targeting nano-micelles and UMC was able to inhibit TNBC tumor growth effectively at lower concentrations while reducing treatment-related toxicity. Thus, this is a very promising treatment strategy in the clinical therapy with TNBC and other cancer types.Triple-negative breast cancer (TNBC) is highly recurring and metastatic breast cancer with overexpressing epidermal growth factor receptor (EGFR). Herein, a series of in vitro and in vivo analyses were used to explore the therapeutic effect of EGFR-targeting nano-micelles (PLGA-PEG/DOX@anti-EGFR) combined with ultrasound-mediated cavitation (UMC). The prepared nano-micelle drug carriers have good biocompatibility and can greatly increase the drug accumulation in tumor regions, thereby reducing off-target toxicity while enhancing anti-tumor efficacy. Moreover, an in vivo analysis of the practical utility of this treatment modality was conducted by using SonoVueTM microbubbles to achieve cavitation under different power intensity levels, with an ultrasonic power intensity of 0.5 W/cm2 maximizing the intra-tumoral blood perfusion. Relative to PLGA-PEG@DOX/anti-EGFR nano-micelles treatment alone, the combination with UMC was better able to suppress tumor growth even at low concentrations. As such, combining actively targeted drug-carrier molecules with UMC represents an effective approach to enhancing therapeutic efficacy while reducing the adverse, systemic effects associated with DOX and other chemotherapeutic drugs, and it can be considered as a promising clinical prospect in the treatment of TNBC.

Abstract 120: Compartmentalized functions of epidermal growth factor receptor (EGFR) in tumorigenesis and malignant phenotypes

Abstract Previous studies demonstrated that nuclear EGFR is associated with malignancy and resistance to tyrosine kinase inhibitor (TKI). To decipher the cellular compartmentalized functions and underlying mechanism of EGFR, we generated EGFR mutants at nuclear translocation signal (NLS) and nuclear export signal (NES). The results showed that EGFR NLS mutant with decreased nuclear translocation sensitized the cancer cells to TKI and impaired invasiveness and stemness of the cancer cells. In contrast, EGFR NES mutant with increased nuclear accumulation promoted aggressiveness of the cancer cells including TKI resistance. Next, we generated genetically engineered mouse model (GEMM) to validate the resulting phenotypes of the EGFR mutants. To this end, CRISPR-Cas9-mediated genome editing approach was used for generating EGFR mutant knock-in mouse, which harbors an internalization-deficient mutation (EGFRLL/AA), pro-nuclear (NES) mutation (EGFRL749P(S)) and the dual mutations. Upon EGF stimulation nuclear EGFR (nEGFR) accumulation in the hepatocytes from EGFRL749P heterozygous mice was increased. Conversely, a significant reduction of nEGFR was observed in the hepatocyte from EGFTRLL/AA homozygous mice. We found that germline expression of EGFRL749P(S) gave rise to deficiency in breeding. However, EGFRLL/AA mutant mice displayed no gross abnormal even in homozygous offspring, suggesting that depletion of nEGFR has no significant phenotype. We failed to generate homozygotes of EGFR NES mutant mice due to embryonic lethality. Of note, the female and male founders and F1 EGFRL798P(S) mice developed tumors with huge spleen. The IHC staining results indicated that the infiltrating lymphocytes in liver, stomach and kidney were B cells. The latency of the B cell lymphomagenesis was from 17 to 23 months, and tumor incidence of F1 offspring of EGFRL749P(S) knock-in mice was 10 of 15 (66.7%). These findings indicated that single allele mutation in EGFR NES domain is capable of driving lymphomagenesis, suggesting that the EGFR NES mutant possesses a strong oncogenic activity. Surprisingly, by searching database of EGFR mutation in human tumors (Cosmic database https://cancer.sanger.ac.uk/cosmic ), we noticed that among the somatic mutations in EGFR gene the gene amplification represents only small part of the gene alternations in human cancers, and EGFR L747P and L747S mutation occur in the lung cancer patients with intrinsic TKI resistance. In addition, the majority of human B lymphocyte originated tumors harboring EGFR NES mutation are also heterozygotes. Cosmic database shows that somatic mutations at the EGFR NES region occur in the patients with plasma cell lymphoma. Taken together, our findings suggest that nEGFR contributes to malignant potential of the tumors and EGFR with NES mutation is a tumor driver. Citation Format: Lei Nie, Junwei Hou, Yu-Yi Chu, Ying-Nai Wnag, Li-Chuan Chan, Longfei Huo, Paul Chiao, Shao-Chun Wang, Mien-Chie Hung, Michael Wang. Compartmentalized functions of epidermal growth factor receptor (EGFR) in tumorigenesis and malignant phenotypes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 120.

Aging Regulated Through a Stability Model of Insulin/Insulin Growth Factor Receptor Function.

Mutations of the insulin-like receptor in Drosophila extend lifespan. New research suggests this receptor operates in two modes. The first extends lifespan while slowing reproduction and reducing growth. The second strongly extends lifespan without impairing growth or reproduction; it confers longevity assurance. The mutation that confers longevity assurance resides in the kinase insert domain, which contains a potential SH2 binding site for substrate proteins. We apply a recent model for the function of receptor tyrosine kinases to propose how insulin receptor structure can modulate aging. This concept hypothesizes that strong insulin-like ligands promote phosphorylation of high threshold substrate binding sites to robustly induce reproduction, which impairs survival as a consequence of trade-offs. Lower levels of receptor stimulation provide less kinase dimer stability, which reduces reproduction and extends lifespan by avoiding reproductive costs. Environmental conditions that favor diapause alter the expression of insulin ligands to further repress the stability of the interacting kinase domains, block phosphorylation of low threshold substrates and thus induce a unique molecular program that confers longevity assurance. Mutations of the insulin receptor that block low-phosphorylation site interactions, such as within the kinase insert domain, can extend lifespan while maintaining overall dimer stability. These flies are long-lived while maintaining reproduction and growth. The kinase insert domain of Drosophila provides a novel avenue from which to seek signaling of the insulin/insulin-like growth factor system of humans that modulate aging without impacting reproduction and growth, or incurring insulin resistance pathology.

Enriched Environment Promotes Adult Hippocampal Neurogenesis through FGFRs.

The addition of new neurons to existing neural circuits in the adult brain remains of great interest to neurobiology because of its therapeutic implications. The premier model for studying this process has been the hippocampal dentate gyrus in mice, where new neurons are added to mature circuits during adulthood. Notably, external factors such as an enriched environment (EE) and exercise markedly increase hippocampal neurogenesis. Here, we demonstrate that EE acts by increasing fibroblast growth factor receptor (FGFR) function autonomously within neurogenic cells to expand their numbers in adult male and female mice. FGFRs activated by EE signal through their mediators, FGFR substrate (FRS), to induce stem cell proliferation, and through FRS and phospholipase Cγ to increase the number of adult-born neurons, providing a mechanism for how EE promotes adult neurogenesis.SIGNIFICANCE STATEMENT How the environment we live in affects cognition remains poorly understood. In the current study, we explore the mechanism underlying the effects of an enriched environment on the production of new neurons in the adult hippocampal dentate gyrus, a brain area integral in forming new memories. A mechanism is provided for how neural precursor cells in the adult mammalian dentate gyrus respond to an enriched environment to increase their neurogenic output. Namely, an enriched environment acts on stem and progenitor cells by activating fibroblast growth factor receptor signaling through phospholipase Cγ and FGF receptor substrate proteins to expand the pool of precursor cells.

Role of GM3 ganglioside in the pathology of some progressive human diseases and prognostic importance of serum anti-GM3 antibodies

Glycosphingolipids (gangliosides) have been characterized as important biological molecules with a key role as regulators in many physiological processes on cellular, tissue, organ, and organism levels. The deviations in their normal amounts, production, and metabolism are very often related to the development of many multi-factor socially important diseases. GM3 ganglioside, as a small molecule, plays important roles in the cascade regulatory pathways in the pathology of many disorders like neurodegenerative diseases, autoimmune diseases, inflammation, diabetes, malignant transformation, and others. Ganglioside GM3 and its derivatives are membrane-bound glycosphingolipids composed of an oligosaccharide head structure containing one sialic acid residue. These molecules transduce signals involved in cell surface events, including the phosphorylation of transmembrane receptors. This ganglioside is the most widely distributed among tissues, and it serves as a precursor for most of the more complex ganglioside species. GM3 inhibits the function of fibroblast growth factor receptor, and cell growth is regulated by GM3-enriched microdomain. GM3 is thought to inhibit immunologic functions, such as the proliferation and production of cytokines by T cells. On the other hand, the anti-ganglioside antibodies (AGAs) are important in many acquired demyelinating immunemediated neuropathies, like Multiple sclerosis (MS), Guillain–Barré syndrome (GBS) and its variation, Miller–Fisher syndrome (MFS) and could be suggested as important diagnostic and prognostic markers about the describe diseases and their etiology. We show that the complexes of anti-ganglioside antibodies to GM3 (detected by ELISA) may be useful diagnostic and prognostic tool markers for autoimmune diseases, neurodegenerative disorders, malignancy, diabetes, and inflammation. Our pilot studies suggest increased serum IgG anti-GM3 antibodies titers in patients with secondary progressive MS (SPMS), throat cancer, elder people with diabetes (89–96 years), old Lewis rats (30–33 months), and in the serum of subjected on lead intoxication BALB/c mice treated by salinomycin. We observed no changes in the titers in healthy elder people (89–96 years), in 70-year-old woman on dialysis, in relapsing-remitting MS (RRMS) patients on long-term treatment with Glatiramer acetate, Laquinimod, and Interferons, as well as in 18– 22 months old Wistar rats and subjected on lead intoxication BALB/c mice treated by monensin and dimercaptosuccinic acid (DMSA). Considerable decrease of serum GM3 in early MS correlate with early damage and severe destruction of the blood–brain barrier, which provides impetus to initiate early therapy.

Abstract PO-042: FGFR1 expression correlates inversely with the in vitro and in vivo efficacy of FGFR inhibitors in pancreatic cancer

Abstract Aberrant functions of fibroblast growth factor receptors (FGFR) have been implicated in the tumor progression of pancreatic cancer (PaCA). However, the mechanisms of FGFR action and the therapeutic utilities of FGFR inhibitors (FGFRi) in PaCA remain largely under-investigated. Here the mechanisms of FGFR inhibition in PaCA were investigated using pan-FGFRi that are under clinical development and specific shRNA against individual FGFRs. FGFRi treatment, such as BGJ398 and AZD4547, significantly inhibited cell proliferation, migration, and invasion, and cell expression of key markers associated with cell survival and invasiveness was suppressed, in multiple PaCA cell lines. Gemcitabine (Gem) is the standard-of-care for PaCA, and the development of Gem resistance (GemR) compromises its efficacy, thereby Gem only provides modest survival benefits. We found that FGFRi was effective in inhibiting cell proliferation, migration of strongly GemR cells and tumors (named as MIA-GR8 cells and MIA-GR8 tumors) that were all derived by increasing Gem exposure from MIA PaCa-2 cells in vitro and selected by Gem in vivo. These results suggest its potential clinical utility as a class of alternative drug candidates in tumors that acquired GemR. Downregulation of GemR markers mediated by FGFRi treatment in GemR cells also suggested its therapeutic application of FGFRi in combination with Gem, in order to overcome GemR. Mechanistically, the molecular mechanisms of individual FGFR were investigated. shRNA-mediated inhibition of FGFR2 or FGFR3 did not decrease cell growth, and the overexpression of FGFR1 promoted cell migration rather than proliferation. Furthermore, the efficacy of FGFRi treatment was investigated in multiple cell lines and patient-derived xenograft. The inhibitory effects of BGJ398 in PANC-1 cell growth and migration were compromised by exogenic overexpression of FGFR1, and its efficacy on cell viability suppression was correlated with FGFR1 in multiple cell lines. In patient-derived xenografts, the efficacy of FGFRi on tumor growth inhibition was also correlated with FGFR1 expression. These data provide evidence that precision medicine which targets FGFR using FGFRi in PaCA tumors which express relatively modest or low amount of FGFR1 could be more effective than that with a high FGFR1 expression. Citation Format: Qingxiang Lin, Andrea Serratore, Eugene Kandel, Robert M. Straubinger. FGFR1 expression correlates inversely with the in vitro and in vivo efficacy of FGFR inhibitors in pancreatic cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2020 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2020;80(22 Suppl):Abstract nr PO-042.

PDGFRB as a potential therapeutic target of ankylosing spondylitis: validation following bioinformatics analysis

Ankylosing spondylitis (AS) is a chronic, progressive, and inflammatory disease that mainly affects the central axis joint. Although this disease has already been well documented and studied, its pathogenesis is still not well understood. This study aimed to screen and identify key candidate genes involved in the progression of AS. For this purpose, expression profiles of GSE39340 and GSE41038 were downloaded from the Gene Expression Omnibus and displayed in the form of volcano plots and heatmaps. Differentially expressed genes (DEGs) were identified by the Limma package in R and functional enrichment analyses were performed. Moreover, STRING and Cytoscape were utilized to construct protein-protein interaction (PPI) networks and screen significant modules. Immunohistochemistry (IHC) in tissue chips of AS and normal human synovial tissues was performed to confirm the major proteins associated with its development. Western blotting (WB) and alizarin red staining were applied to validate the expression level of platelet-derived growth factor receptor beta (PDGFRB) and function during osteogenesis differentiation of fibroblasts in AS. A total of 256 DEGs were screened, including 191 up-regulated genes and 65 down-regulated genes. The enriched functions of these identified genes mainly included adherens junction, focal adhesion, and cell-substrate adherens junction. The pathways most highly associated with the progression of AS were TGF-β signaling pathway, the Hippo signaling pathway, and the AGE-RAGE signaling pathway. In addition, IHC showed that mitogen-activated protein kinase 1 (MAPK1), C-X-C motif chemokine receptor 4 (CXCR4), and PDGFRB were highly expressed in AS. PDGFRB was found upregulated during osteogenesis of fibroblasts and stimulates osteogenesis in AS. These findings may improve our understanding of the molecular mechanisms controlling AS. Pharmacological targeting of PDGFRB may initiate a possible suppression of bone formation in AS.

Abstract 5197: A systems approach to evaluating the effects of two EGFR-targeted therapies on cellular models of human skin and lung cancer using an integrated imaging and analysis platform and the rapid quantification of multiple key biomarkers

Abstract The physiological function of the epidermal growth factor receptor (EGFR) is to regulate epithelial tissue development and homeostasis, but its overexpression and activation are strongly linked to oncogenesis and tumor progression in a variety of human cancers. Many EGFR-targeted therapies have been developed which alone have proven to be effective, but resistance often develops, indicating a need for more studies probing the efficacy of combinatorial drug treatments. These studies will further require the discovery and characterization of biomarkers that can predict therapeutic efficacy and resistance. The purpose of this study was to examine the effects of individual and combined treatment with two classical EGFR-targeted therapies with different modes of action on cellular models of human skin cancer and non-small cell lung carcinoma (NSCLC). We characterized the effects of a two-day treatment with varying concentrations of EGF on cellular health and proliferation and on the expression of several key biomarker proteins in A431 and A549 cell lines. We then examined the individual and combined effects of treatment with the tyrosine kinase inhibitor (TKI) gefitinib and the humanized monoclonal antibody cetuximab. Cellular growth, proliferation and health were assessed with ATPlite luminescence assays and well-imaging and cytometry measures using a high-throughput multimodal imager and plate reader. Biomarkers measured included EGFR, immune checkpoint proteins (PD-L1 and CD276/B7-H3), chemokines (IL-8/CXCL8 and GRO-α/CXCL1), a protease inhibitor (TIMP-2), and growth factor (VEGF). All these biomarker proteins were rapidly assessed using AlphaLISA no-wash, mix-and-read assays on 5 μL samples collected from the same wells of the culture plate. We observed that EGF treatment resulted in decreased EGFR expression and upregulation of PD-L1 protein in a dose-dependent manner in both culture models. CD276, VEGF and TIMP-2 expression levels, however, were upregulated with EGF treatment only in the A431 cells. Complex drug treatment effects on biomarker expression are presented. In addition, treatment effects on EGFR phosphorylation and downstream signaling pathways (including MEK/ERK and AKT) were probed using AlphaLISA SureFire Ultra phosphorylation assays and demonstrate the different pathways effected by either drug or a combination of both. These data illustrate the effects of EGFR stimulation on the expression of an array of biomarkers and signaling pathways and in the cellular tolerance for individual and combined treatment with two EGFR-targeted therapies with different mechanisms of action between two different cellular models of human cancer. Citation Format: Jeanine M. Hinterneder, Lauren Berstler, Adam Carlson, Jen Carlstrom. A systems approach to evaluating the effects of two EGFR-targeted therapies on cellular models of human skin and lung cancer using an integrated imaging and analysis platform and the rapid quantification of multiple key biomarkers [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5197.