EGF Receptor Research Articles

Targeted Nanofitin-drug conjugates achieve efficient tumor delivery and therapeutic effect in an EGFR-positive mouse xenograft model.

Adjusting the molecular size, the valency and the pharmacokinetics of drug conjugates are as many leverages to improve their therapeutic window, notably by affecting tumor penetration, renal clearance and short systemic exposure. In that regard, small tumor-targeting ligands are gaining attention. In this study, we demonstrate the benefits of the small Nanofitin alternative scaffolds (7 kDa) as selective tumor-targeting modules for the generation of drug conjugates, focusing on Nanofitins B10 and D8 directed against the Epithelial Growth Factor Receptor (EGFR). Owing to their small size and monovalent format, the two Nanofitins displayed a fast and deep tumor penetration in EGFR-positive A431 xenografts in BALB/c nude mice after intravenous administration, yielding to a targeting of respectively 67.9%±14.1 and 98.9%±0.7 of the tumor cells as demonstrated by immunohistochemistry. Conjugation with the monomethyl auristatin E toxin provided homogeneous Nanofitin-drug conjugates, with an overall yield of ≥97%, for in vivo assessment in a curative xenograft model using bioluminescent, EGFR-positive, A431 cells in BALB/c nude mice. Internalization was found critical for efficient release of the toxin. Hence, the intravenous administration of the D8-based construct showed significant anti-tumor effect in vivo as determined by monitoring tumor volumes and bioluminescence levels over 2 months.

Caffeic acid phenethyl ester surmounts acquired resistance of AZD9291 in non-small cell lung cancer cells.

Epithelial growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the first-line therapy for EGFR mutated non-small cell lung cancer (NSCLC); however, resistance rapidly develops. The objective of this study was therefore to establish and characterize a gefitinib resistant NSCLC line (HCC827GR) and evaluate the therapeutic effects of natural products in combination with third-generation EGFR-TKI, AZD9291. The IC50 of gefitinib and AZD9291 in HCC827GR were significantly higher than those of HCC827 (p < 0.05). Furthermore, anchorage-independent colony assay indicated that HCC827GR cells were more aggressive than their predecessors. This was reflected by the gene/protein expression changes observed in HCC827GR versus HCC827 profiled by cancer drug resistance real-time polymerase chain reaction (RT-PCR) array and Western blot. Three natural products were screened and caffeic acid phenethyl ester (CAPE) exhibited the most significant combinative cytotoxic effect with AZD9291. Specifically, flow cytometry revealed that AZD9291 + CAPE considerably increased the fraction of cell in pre-G1 of the cell cycle and caspase-Glo3/7 assay showed a dramatic increase in apoptosis when compared to AZD9291 alone. Furthermore, Western blot showed significant downregulation of p-EGFR/p-AKT in HCC827GR cells treated with AZD9291 + CAPE as compared to AZD9291. Moreover, it is evident that AZD9291 + CAPE specifically resulted in a marked reduction in the protein expressions of the cell-proliferation-related genes p21, cyclin D1, and survivin. Finally, refined RT-PCR/Western blot data indicated that AZD9291 + CAPE may at least partially exert its synergistic effects via the PLK2 pathway. Together, these results suggest that CAPE is a clinically relevant compound to aid AZD9291 in treating EGFR-TKI resistant cells through modulating critical genes/proteins involved in cancer resistance/therapy.

Steric-Deficient Oligoglycine Surrogates Facilitate Multivalent and Bifunctional Nanobody Synthesis via Combined Sortase A Transpeptidation and Click Chemistry.

Conferring multifunctional properties to proteins via enzymatic approaches has greatly facilitated recent progress in protein nanotechnology. In this regard, sortase (Srt) A transpeptidation has facilitated many of these developments due to its exceptional specificity, mild reaction conditions, and complementation with other bioorthogonal techniques, such as click chemistry. In most of these developments, Srt A is used to seamlessly tether oligoglycine-containing molecules to a protein of interest that is equipped with the enzyme's recognition sequence, LPXTG. However, the dependence on oligoglycine attacking nucleophiles and the associated cost of certain derivatives (e.g., cyclooctyne) limit the utility of this approach to lab-scale applications only. Thus, the quest to identify appropriate alternatives and understand their effectiveness remains an important area of research. This study identifies that steric and nucleophilicity-associated effects influence Srt A transpeptidation when two oligoglycine surrogates were examined. The approach was further used in complementation with click chemistry to synthesize bivalent and bifunctional nanobody conjugates for application in epithelial growth factor receptor targeting. The overall technique and tools developed here may facilitate the advancement of future nanotechnologies.

Identification of EGF Receptor and Thrombospondin-1 as Endogenous Targets of ER-Associated Degradation Enhancer EDEM1 in HeLa Cells.

Secretory and membrane proteins are vital for cell activities, including intra- and intercellular communication. Therefore, protein quality control in the endoplasmic reticulum (ER) is an essential and crucial process for eukaryotic cells. Endoplasmic reticulum-associated degradation (ERAD) targets misfolded proteins during the protein maturation process in the ER and leads to their disposal. This process maintains the ER productive function and prevents misfolded protein stress (i.e., ER stress). The ERAD-stimulating factor ER degradation-enhancing α mannosidase-like 1 protein (EDEM1) acts on misfolded proteins to accelerate ERAD, thereby maintaining the productivity of the ER. However, the detail mechanism underlying the function of EDEM1 in ERAD is not completely understood due to a lack of established physiological substrate proteins. In this study, we attempted to identify substrate proteins for EDEM1 using siRNA. The matrix component thrombospondin-1 (TSP1) and epidermal growth factor receptor (EGFR) were identified as candidate targets of EDEM1. Their protein maturation status and cellular localization were markedly affected by knockdown of EDEM1. We also showed that EDEM1 physically associates with EGFR and enhances EGFR degradation via ERAD. Our data highlight the physiological role of EDEM1 in maintaining specific target proteins and provide a potential approach to the regulation of expression of clinically important proteins.

A Novel and Versatile Microfluidic Device for Cell Assays under Radio Frequency Exposure.

Wound healing is a complex process composed of different stages, which involves extensive communication between the different cellular factors of the extracellular matrix (ECM). The radio frequency electromagnetic field (RF-EMF) has been used to accelerate the wound-healing process and it has been found to enhance cell alignment and mobility. The conventional methods for cell mobility analysis in an electromagnetic field generated by a radiation source are not advisable due to the low-precision, nonuniform distribution of the field, low efficiency of the analysis in batch and the lack of system integration for autonomous on-body operation. Here, a novel and versatile electromagnetic exposure system integrated with a microfluidic chip was fabricated to explore the EMF-induced response. A gradient electromagnetic field in a two-dimensional plane has been successfully established in the microchambers placed along the field line. In this work, by deploying our radiation experiments in vitro, we validated the on-chip monitoring of cell response to exposure. This electromagnetic field was simulated and human amniotic epithelial cells (HAECs) were cultured in different microchambers for continuous exposure to the electromagnetic field excited by a monopole RF antenna (1.8 GHz). New protrusions were generated and an obvious increase in filopodia with the increased field intensity was investigated. Meanwhile, the variation in intracellular Ca2+ concentration under the electromagnetic field was examined. The inhibitory effect of the Ca2+ circulation was further inspected to reveal the potential downstream signaling pathway in the RF-EMF-related bioassay, suggesting that cytoskeletal dynamics of cells under exposure are highly associated with the EGF receptor (EGFR)-cytoskeleton downstream signaling pathway. Finally, the field-induced cell elongation and alignment parallel to the field direction were observed. Additionally, the subsequent recovery (field withdrawal) and re-establishment (field re-exposure) were explored. These results indicated that this reliable and versatile exposure system for bioassay could achieve precise and high-throughput detection of the RF-EMF-induced cytoskeletal reorganization in vitro and evaluate the possible health risk from RF-EMF exposure.

Dissecting the Methylomes of EGFR-Amplified Glioblastoma Reveals Altered DNA Replication and Packaging, and Chromatin and Gene Silencing Pathways.

Glioblastoma IDH wildtype is the most frequent brain tumor in adults. It shows a highly malignant behavior and devastating outcomes. To date, there is still no targeted therapy available; thus, patients' median survival is limited to 12-15 months. Epithelial growth factor receptor (EGFR) is an interesting targetable candidate in advanced precision medicine for brain tumor patients. In this study, we performed integrated epigenome-wide DNA-methylation profiling of 866,895 methylation specific sites in 50 glioblastoma IDH wildtype samples, comparing EGFR amplified and non-amplified glioblastomas. We found 9849 significantly differentially methylated CpGs (DMCGs) with Δβ ≥ 0.1 and p-value < 0.05 in EGFR amplified, compared to EGFR non-amplified glioblastomas. Of these DMCGs, 2380 were annotated with tiling (2090), promoter (117), gene (69) and CpG islands (104); 7460 are located at other loci. Interestingly, the list of differentially methylated genes allocated eleven functionally relevant RNAs: five miRNAs (miR1180, miR1255B1, miR126, miR128-2, miR3125), two long non-coding RNAs (LINC00474, LINC01091), and four antisense RNAs (EPN2-AS1, MNX1-AS2, NKX2-2-AS1, WWTR1-AS1). Gene ontology (GO) analysis showed enrichment of "DNA replication-dependent nucleosome assembly", "chromatin silencing at rDNA", "regulation of gene silencing by miRNA", "DNA packaging", "posttranscriptional gene silencing", "gene silencing by RNA", "negative regulation of gene expression, epigenetic", "regulation of gene silencing", "protein-DNA complex subunit organization", and "DNA replication-independent nucleosome organization" pathways being hypomethylated in EGFR amplified glioblastomas. In summary, dissecting the methylomes of EGFR amplified and non-amplified glioblastomas revealed altered DNA replication, DNA packaging, chromatin silencing and gene silencing pathways, opening potential novel targets for future precision medicine.

Comparison of EGFR (Epithelial Growth Factor Receptor) expression as a protein marker in Oral Erosive &amp; Reticular Lichen Planus and Oral Epithelial Dysplasia

Comparison of EGFR (Epithelial Growth Factor Receptor) expression as a protein marker in Oral Erosive &amp; Reticular Lichen Planus and Oral Epithelial Dysplasia

An ELISA Test Able to Predict the Development of Oral Cancer: The Significance of the Interplay between Steroid Receptors and the EGF Receptor for Early Diagnosis.

Oral disorders including non-homogeneous leukoplakia, erythroplakia, erosive lichen planus, and many others can potentially progress to oral squamous cell carcinoma (OSCC). Currently, the late diagnosis of OSCC contributes to high mortality rates, emphasizing the need for specific markers and early intervention. In this study, we present a novel, quick, sensitive, and non-invasive method for the early detection and screening of oral cancer, enabling the qualitative assessment of neoplastic forms even before the onset of symptoms. Our method directly examines the expression of oral cancer biomarkers, such as the epithelial growth factor receptor (EGFR), and steroid receptors, including the androgen receptor (AR) and the estrogen receptor (ER). The crosstalk between sexual hormones and the EGF receptor plays a crucial role in the progression of different types of cancers, including head and neck squamous cell carcinoma. To implement our method, we developed a kit box comprising nine wells or stations, each containing buffers, lysis systems, and dried/lyophilized antibodies stored at room temperature. The kit includes instruments for sample collection and a PVDF strip (Immobilon) with specific primary antibodies immobilized on it. These antibodies capture the target proteins from cytological samples. Additionally, complementary tools are provided to ensure efficient utilization and optimal test performance. The technique can be performed outside the laboratory, either "patient side" with an instant chemocolorimetric response or with a digital reader utilizing the enzyme-linked immunosorbent assay (ELISA) method.

Leveraging innate immunity with AFM24, a novel CD16A and epidermal growth factor receptor (EGFR) bispecific innate cell engager: Interim results for the non-small cell lung cancer (NSCLC) cohort.

2533 Background: Patients with EGFR mutant NSCLC who progress on or after small molecule EGFR inhibitors have only limited treatment options. AFM24 is a tetravalent, bispecific innate cell engager that binds EGFR on solid tumor cells and CD16A on NK cells to redirect and enhance antitumor antibody-dependent cellular cytotoxicity, thus acting independently of the EGFR downstream signaling pathway and EGFR expression levels. The Phase 1 dose escalation phase of the presented study (NCT04259450) established the recommended Phase 2 dose of AFM24 monotherapy at 480 mg based on tolerability, receptor occupancy, and pharmacokinetics (PK). Correlative science data revealed an activation and enrichment of immune cells in the tumor microenvironment. Methods: The Phase 2a expansion phase is evaluating 480 mg AFM24 in patients with EGFR mutant NSCLC, relapsed or refractory to ≥1 prior lines of therapy; EGFR-positivity is defined as positive staining for EGFR in ≥1% of tumor cells per local immunohistochemistry assay. The study follows Simon’s two-stage design. The primary endpoint is overall response rate per local RECIST v1.1; secondary endpoints include safety, PK, and immunogenicity. Efficacy per iRECIST is an exploratory endpoint. AFM24 is administered intravenously once weekly in a 28-day cycle. Tumor assessments are performed at initial screening, cycles 2, 4, 6, 8, and every 3 cycles thereafter. Results: As of December 2022, 14 patients (median [range] age 55 [37–82]; 12 male; 11 Asian, 3 White) were enrolled; the median number of prior therapies was 2.5 (1–12). Median treatment duration with AFM24 was 6.7 weeks (1.0–26.1). Best objective response in 10 evaluable patients was confirmed partial response in 1 patient (change from baseline –45%); 4 patients exhibited stable disease, 1 was confirmed. Tumor shrinkage occurred in 2 patients with stable disease (–6%, –18%). The tumor control rate was 50%. Treatment-related adverse events (TRAEs) were reported in 13 patients; infusion related reactions (IRRs, 12), dermatitis acneiform, neutrophil count decreased, decreased appetite, and myalgia (2 each) were most common. Grade ≥3 TRAEs occurred in 4 patients and included decreased neutrophil count (2), lymphopenia, and IRR (1 each). Grade 5 pneumonitis was observed in 1 patient with disease progression and multiple comorbidities; relation to AFM24 could not be ruled out. As of January 2023, enrollment is ongoing; results of the interim analysis will be presented. Conclusions: AFM24 demonstrated clinical activity and acceptable safety in heavily pretreated patients with EGFR mutant NSCLC. The novel mechanism of action of AFM24 could add to the therapeutic options for patients with EGFR expressing tumors and is under clinical evaluation as a single agent and in combination with atezolizumab or autologous NK cells. Clinical trial information: NCT04259450 .

Newly Synthesized Arylazo Derivatives Induce Apoptosis and G2/M Cell Cycle Arrest With Molecular Docking Validation in Human Cancer Cell Lines.

We reported herein the synthesis of novel arylazo derivatives 3a-e incorporating isoquinoline moiety. A coupling reaction of 2-(6,7-dimethoxy-3,4-dihydroisoquinolin-1-yl)acetonitrile 1 with diazotized heterocyclic amines 2 in ethanol in the presence of sodium acetate to give arylazo derivatives 3a-e. Cytotoxic effect of five arylazo derivatives on breast carcinoma MCF7 and hepatocellular carcinoma HepG2 was carried out, followed by molecular and functional-based assays, to estimate the anticancer effect of these compounds. The fibroblast growth factor receptor (FGFR) and epithelial growth factor receptor (EGFR) were found to interact and bind with the compounds 3a and 3d through several hydrophobic and hydrogen bonds, which were validated by molecular docking. The two promising compounds 3a and 3d demonstrated various anticancer potential activities on tumorigenesis, cytotoxicity, and apoptotic effects, exhibited in the deregulation of the expression of different genes involved in apoptotic and anti-apoptotic mechanisms, cell cycle arrest at G2/M, and induction of apoptosis in both cell lines.

Survival outcomes of young patients under 40 with breast cancer in Asian countries according to subtype: An international multicenter cohort study.

562 Background: The incidence of young Asian women with breast cancer has been increasing but these patients are underrepresented in global data. We analyzed the epidemiology and outcomes of the young Asian patients with breast cancer in different subtypes with clinically unmet need. Methods: Female patients of age 20 years or older diagnosed with early breast cancer of stage I, II, or III from the prospective cohort of the Asian Breast Cancer Cooperative Group (ABCCG) were analyzed. For comparison, data of patients with early breast cancer from Surveillance, Epidemiology, and End Results Program (SEER) cancer registry was used. The patients were divided into three age groups: young (below 40 years), alleged premenopausal mid-age (40-49 years), and alleged postmenopausal elderly (50 years and older). Multivariable Cox proportional-hazard models for survivals were adjusted with age, subtypes consisting of hormone receptor (HR) and human epithelial growth factor receptor 2 (HER2) status, histologic grade, T stage, nodal status, and countries. Patients diagnosed in 2000–2010 were censored at 6 years for comparability with SEER database. Results: Total 45,021 patients with breast cancer from Asian countries, 496,332 of SEER Whites and 18,279 from SEER non-Whites were included. The median age at diagnosis was younger in Asians compared to SEER Whites and non-Whites (51, 62, 58 years, respectively). Among subtypes, HR-positive and HER2-negative breast cancer was more frequent among SEER Whites and SEER non-Whites, compared to Asians (75.89%, 73.38% vs. 65.75%, respectively). In the young group, HR-positive and HER2-negative breast cancer was prevalent in Asians and SEER non-Whites, compared to SEER Whites (61.2% and 59.8% vs. 54.7%, respectively). In the elderly group, the proportion of HR-positive breast cancer increased in SEER Whites, while that of triple-negative breast cancer (TNBC) increased in Asians. Elderly group showed the worst survival in all subtypes and in all populations. In Asian population, the mid-age group of the patients with HR-positive and HER2-negative breast cancer showed significantly superior overall survival (OS) than the young group (6 year OS 96.6% vs. 94.4%; hazard ratio 0.62, 95% confidence interval 0.50-0.76; p&lt;0.001). Similarly, young patients in SEER Whites also showed early decline of survival curve compared those in mid-age group (89.1% vs. 94.0%, p&lt;0.001), while young patients of SEER non-Whites showed equivalent prognosis to those in mid-age group (92.4% vs. 95.0%, p=0.118). Conclusions: Young Asian breast cancer patients diagnosed with HR-positive and HER2-negative subtypes, but not HER2-positive or TNBC subtypes, are more likely to have worse survival outcomes than those in mid-age. Further studies on young patients with breast cancer are needed for tailored treatments among different subtypes and ethnic groups.

How Driver Oncogenes Shape and Are Shaped by Alternative Splicing Mechanisms in Tumors.

The development of RNA sequencing methods has allowed us to study and better understand the landscape of aberrant pre-mRNA splicing in tumors. Altered splicing patterns are observed in many different tumors and affect all hallmarks of cancer: growth signal independence, avoidance of apoptosis, unlimited proliferation, invasiveness, angiogenesis, and metabolism. In this review, we focus on the interplay between driver oncogenes and alternative splicing in cancer. On one hand, oncogenic proteins-mutant p53, CMYC, KRAS, or PI3K-modify the alternative splicing landscape by regulating expression, phosphorylation, and interaction of splicing factors with spliceosome components. Some splicing factors-SRSF1 and hnRNPA1-are also driver oncogenes. At the same time, aberrant splicing activates key oncogenes and oncogenic pathways: p53 oncogenic isoforms, the RAS-RAF-MAPK pathway, the PI3K-mTOR pathway, the EGF and FGF receptor families, and SRSF1 splicing factor. The ultimate goal of cancer research is a better diagnosis and treatment of cancer patients. In the final part of this review, we discuss present therapeutic opportunities and possible directions of further studies aiming to design therapies targeting alternative splicing mechanisms in the context of driver oncogenes.

Insights into the leveraging of GABAergic signaling in cancer therapy.

Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain of adult mammals. Several studies have demonstrated that the GABAergic system may regulate tumor development via GABA receptors, downstream cyclic adenosine monophosphate (cAMP) pathway, epithelial growth factor receptor (EGFR) pathway, AKT pathway, mitogen-activated protein kinase (MAPK) or extracellular signal-related kinases (ERK) pathway, and matrix metalloproteinase (MMP) pathway, although the exact mechanism is unclear. Pioneering studies reported that GABA signaling exists and functions in the cancer microenvironment and has an immunosuppressive effect that contributes to metastasis and colonization. This article reviews the molecular structures and biological functions of GABAergic components correlated with carcinogenesis, the mechanisms underlying GABAergic signaling that manipulate the proliferation and invasion of cancer cells, and the potential GABA receptor agonists and antagonists for cancer therapy. These molecules may provide an avenue for the development of specific pharmacological components to prevent the growth and metastasis of various cancers.

An unanticipated discourse of HB-EGF with VANGL2 signaling during embryo implantation

Implantation is the first direct encounter between the embryo and uterus during pregnancy, and Hbegf is the earliest known molecular signaling for embryo-uterine crosstalk during implantation. The downstream effectors of heparin-binding EGF (HB-EGF) in implantation remain elusive due to the complexity of EGF receptor family. This study shows that the formation of implantation chamber (crypt) triggered by HB-EGF is disrupted by uterine deletion of Vangl2, a key planar cell polarity component (PCP). We found that HB-EGF binds to ERBB2 and ERBB3 to recruit VANGL2 for tyrosine phosphorylation. Using in vivo models, we show that uterine VAGL2 tyrosine phosphorylation is suppressed in Erbb2/Erbb3 double conditional knockout mice. In this context, severe implantation defects in these mice lend support to the critical role of HB-EGF-ERBB2/3-VANGL2 in establishing a two-way dialogue between the blastocyst and uterus. In addition, the result addresses an outstanding question how VANGL2 is activated during implantation. Taken together, these observations reveal that HB-EGF regulates the implantation process by influencing uterine epithelial cell polarity comprising VANGL2.

AQP3-Dependent PI3K/Akt Modulation in Breast Cancer Cells.

Aquaporin 3 (AQP3) is a peroxiporin, a membrane protein that channels hydrogen peroxide in addition to water and glycerol. AQP3 expression also correlates with tumor progression and malignancy and is, therefore, a potential target in breast cancer therapy. In addition, epithelial growth factor receptor (EGFR) plays an important role in breast cancer. Therefore, we investigated whether disruption of the lipid raft harboring EGFR could affect AQP3 expression, and conversely, whether AQP3 silencing would affect the EGFR/phosphoinositide-3-kinase (PI3K)/Protein kinase B (PKB or Akt) signaling pathway in breast cancer cell lines with different malignant capacities. We evaluated H2O2 uptake, cell migratory capacity, and expression of PI3K, pAkt/Akt in three breast cancer cell lines, MCF7, SkBr3, and SUM159PT, and in the nontumorigenic breast epithelial cell line MCF10A. Our results show different responses between the tested cell lines, especially when compared to the nontumorigenic cell line. Neither lipid raft disruption nor EGF stimuli had an effect on PI3K/Akt pathway in MCF10A cell line. AQP3-silencing in SkBr3 and SUM159PT showed that AQP3 can modulate PI3K/Akt activation in these cells. Interestingly, SUM159PT cells increase nuclear factor-E2-related factor 2 (NRF2) in response to lipid raft disruption and EGF stimuli, suggesting an oxidative-dependent response to these treatments. These results suggest that in breast cancer cell lines, AQP3 is not directly related to PI3K/Akt pathway but rather in a cell-line-dependent manner.

Abstract LB238: Image-based phenotypic profiling of a chemogenomic screening library identifies nobel targets of known inhibitors

Abstract The gene encoding epidermal growth factor receptor (EGFR) is a major driver gene in cancer. Many drugs targeting EGFR-associated molecules have been developed, yet many have failed in clinical trials due to a lack of efficacy and/or unexpected side effects. In this study, I used image-based phenotypic profiling to screen a pharmacologically active compound library with the aim of identifying new druggable targets in the EGFR pathway. As anticipated, the phenotypic screen identified compounds that produce phenotypes resulting from targeting a known specific molecule or pathway. The assay also showed that compounds with diverse known mechanisms of action produced similar, EGFR-related cellular phenotypes. Biochemical assays revealed that those compounds share a previously unappreciated common target/pathway, showing that the image-based assay can identify new target molecules that are independent of the compound’s known target. Citation Format: Kenji Tanabe. Image-based phenotypic profiling of a chemogenomic screening library identifies nobel targets of known inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB238.

Engineered synthetic nanobody-based biosensors for electrochemical detection of epidermal growth factor receptor

Two engineered synthetic nanobody-based nanobiocomposite platforms were developed for label-free electrochemical detection of the epithelial growth factor receptor (EGFR) biomarker. Screen-printed carbon electrodes (SPCE) were decorated either with NiO nanoparticles (NPs) or poly(thiophene acetic acid) (PTAA) to link the anti-EGFR nanobody (Nb) and form nanobiocomposites for detecting the EGFR biomarker by electrochemical impedance spectroscopy (EIS). The nanoarchitectures were prepared by in situ electrosynthesis of NiO NPs or PTAA layers at SPCEs. A modified version of the 9G8 Nb (Nb9G8m), specific for the EGFR (anti-EGFR), was designed and produced as the nanobiosensor bioreceptor. This Nb was engineered to provide a hexahistidine tag (6xHis-tag) and a lysine (Lys) dual functionality to form a (6xHis-tag)/Ni2+ or Lys/PTAA interface. The biosensing interfaces were characterized by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, cyclic voltammetry, and EIS. The nanobody/nanobiocomposite-based biosensors detected EGFR proteins in a linear range from 0.25 to 50 μg mL−1 and 0.5 to 50 μg mL−1, with limits of detection of 0.46 μg mL−1 and 1.14 μg mL−1, for NiO- and PTAA-based platforms, respectively. The biosensing platforms offer high simplicity, specificity, and selectivity to detect EGFR, but Nbs can be readily engineered to detect other (glycol)proteins. Finally, as a proof of concept, the EGFR was detected in several tumor cell lines, differentiating biomarker expression among them.

Essential oil of lemon myrtle (Backhousia citriodora) induces S-phase cell cycle arrest and apoptosis in HepG2 cells

Ethnopharmacological relevanceLemon myrtle (Backhousia citriodora F.Muell.) leaves, whether fresh or dried, are used traditionally in folk medicine to treat wounds, cancers, skin infections, and other infectious conditions. However, the targets and mechanisms related to anti-cancer effect of lemon myrtle are unavailable. In our study, we found that the essential oil of lemon myrtle (LMEO) showed anti-cancer activity in vitro, and we initially explored its mechanism of action. Materials and methodsWe analyzed the chemical compositions of LMEO by GC-MS. We tested the cytotoxicity of LMEO on various cancer cell lines using the MTT assay. Network pharmacology was used also to analyze the targets of LMEO. Moreover, the mechanisms of LMEO were investigated through scratch assay, flow cytometry analysis, and western blot in the HepG2 liver cancer cell line. ResultsLMEO showed cytotoxicity on various cancer cell lines with values of IC50 40.90 ± 2.23 (liver cancer HepG2 cell line), 58.60 ± 6.76 (human neuroblastoma SH-SY5Y cell line), 68.91 ± 4.62 (human colon cancer HT-29 cell line) and 57.57 ± 7.61 μg/mL (human non-small cell lung cancer A549 cell line), respectively. The major cytotoxic chemical constituent in LMEO was identified as citrals, which accounted for 74.9% of the content. Network pharmacological analysis suggested that apurinic/apyrimidinic endodeoxyribonuclease 1 (APEX1), androgen receptor (AR), cyclin-dependent kinases 1 (CDK1), nuclear factor erythroid 2-related factor 2 (Nrf-2), fatty acid synthase (FASN), epithelial growth factor receptor (EGFR), estrogen receptor 1 (ERα) and cyclin-dependent kinases 4 (CDK4) are potential cytotoxic targets of LMEO. These targets are closely related to cell migration, cycle and apoptosis. Notley, the p53 protein had the highest confidence to co-associate with the eight common targets, which was further confirmed by scratch assay, flow cytometry analysis, and western blot in the HepG2 liver cancer cell line. LMEO significantly inhibited the migration of HepG2 cells in time-dependent and dose-dependent manner. Moreover, LMEO caused a S-phase blocking on HepG2 cells and promoted apoptosis in the meanwhile. Western blot results indicated that p53 protein, Cyclin A2 and Bax proteins were up-regulated, while Cyclin E1 and Bcl-2 proteins were down-regulated. ConclusionLMEO showed cytotoxicity in various cancer cell lines in vitro. Pharmacological networks showed LMEO to have multi-component and multi-targeting effects that are related to inhibit migration of HepG2 cells, and affect cell cycle S-phase arrest and apoptosis through modulation of p53 protein.

Abstract 5141: Macrophage transcriptomic signature validation in scRNA seq and overall survival differences in urothelial carcinoma

Abstract Introduction: While the prognostic value of immune system biomarkers has been well explored, role of cancer associated macrophages in bladder cancer(BC) is unclear due to lack of consistent results, coupled with tissue nonspecific transcriptomic signature. Methodology: Data acquisition from 3,936 patients of The Cancer Genome Atlas (TCGA) in addition to Gene Expression Omninus (GEO) data sets GSE13507, GSE16945, GSE48277, GSE32894, GSE149582, as well as European Genotype Phenotype EGAS000001004507 was obtained. Tumor associated macrophages M1 and M2 were defined utilizing 188 and 159 gene expression profiles via xCell computational algorithm. To obtain bladder tissue residence macrophage signatures, scRNA seq was performed on tissue collected from surgical resection of 5 HG bladder cancer patients and 2 healthy controls. CellRanger software package with default parameters was utilized giving a total of 8,068 cells. FindAllMarkers was utilized for integration of DEG genes (cancer vs control) among the cluster and identification of BC macrophage specific markers. Endpoint of OS were measured in months from the time of cystectomy to follow up. Results: Surprisingly, presence of M1 infiltration was found to be associated with improved OS in two out of eight cohorts only (GSE32894, GSE70691, p&amp;lt;0.001), while the remainder detected no significant difference. Similarly, no association with OS was detected among all 8 cohorts with M2 infiltration. To improve our understanding of tissue specific markers of macrophage population in bladder, we then analyzed macrophage clusters detected within scRNAseq of BC patients compared to healthy. Gene ontology enrichment analysis of functions within tumor specific macrophages demonstrated an exaggerated expression of mTORC1 signaling, PI3K/AKT/mTOR signaling, TGF beta and EGF receptor pathways compared to non-cancer controls. Reanalysis of 22 tissue specific markers for M1/M2 infiltration showed no difference in any of the 8 cohorts with M1 high vs low infiltration. Similarly, addition of M2 infiltration as predictive marker yielded no further associations with OS in all but one cohort (GSE32894, p=0.00041), where high M2 tumor presence was associated with improved OS. Conclusion: Our study represents the largest TAMs evaluation of BC across 8 cohorts with additional scRNA seq exploration of tissue specific signatures, demonstrating no association with OS in bladder cancer. Citation Format: Laura Bukavina, Spencer Bell, Daniel Geynisman, Ilaha Isali, Daniel Ranti, John Sfakianos, Henkel Valentine, Adam Calaway, Alexander Kutikov, Andres Correa, Robert Uzzo, Lee Ponsky, Philip Abbosh. Macrophage transcriptomic signature validation in scRNA seq and overall survival differences in urothelial carcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5141.

Abstract 164: Development of a living biobank of breast cancer organoids

Abstract Introduction: Breast cancer is one of the most frequently diagnosed cancers among women, with a high mortality rate. More than 20 different subtypes of breast cancer are identified. Advancement in patient-derived organoid technology makes it possible to preserve cellular, structural, and tissue microenvironment, which mimics the tissue in vivo. The present study aims to develop a cryopreserved (living) tumor biobank from patient-derived tumor breast tissues. Eventually, biobank organoids will be used to test treatment options outside of patients, in a dish, and provide information on what treatments the patient responds to. Method: Patient-derived organoids (PDOs) were bio-fabricated using an unsorted tumor and normal cell suspension in a collagen-based hydrogel. Immune-enhanced tumor organoids (iTOs) were also bio-fabricated using patient-matched PMBCs and tumor cells. Breast cancer living biobanks were developed by freezing organoids in cryopreservation solutions and reestablishing them in growth media compatible with breast organoids. Histological staining for hormone receptors and Her2 receptor markers was performed. Organoids were cultured for seven days, followed by treatment with chemotherapy (Paclitaxel, Doxorubicin, and Sulphonamide) and immunotherapy (Nivolumab, Pembrolizumab, and Atezolizumab), and assessed for cell viability. Results: H&amp;E staining showed the characteristics of the breast tissue with well-defined acini. In tumor organoids, acini were somewhat perturbed compared to normal breast organoids. Immunofluorescence staining showed the expression of breast biomarkers, including EGF receptor 2 (HER2), Progesterone receptor (PR), and Estrogen receptor (ER). Zona occludin 2 and keratin 19 expression in luminal cells and expression of Keratin 14 and P63 in basal cells, suggesting correct polarization in the organoids. Immunofluorescence staining of iTOs, with T cell markers including CD3, CD4, and CD8, indicated that immune cells remained viable in the iTOs. Drug responses to Doxorubicin, Paclitaxel, Sulphonamide and a combination of Doxorubicin-Paclitaxel showed significant inhibition of cell growth in normal and tumor organoids (p&amp;lt; 0.04). Treatment of breast iTOs showed moderate responses to nivolumab (n=11) and pembrolizumab (n=5), with a 63%-100% efficacy (P &amp;lt; 0.05) respectively. No responses were observed for Atezolizumab (n=5). Drug responses of biobank organoids showed comparable drug sensitivities to their fresh, non-frozen counterparts, suggesting that biobank organoids retain physiological relevant information and can be used for testing new drug therapies. Conclusion: Breast cancer organoids recapitulate the histological features of breast tissue in culture and respond to chemotherapy and immunotherapy. In the future, patient-derived breast tumor organoids can be cryopreserved and serve as living biobanks to provide a platform for personalized medicine. Citation Format: Nadeem Wajih, Richard Erali, Edward A. Levine, Konstantinos Votanopoulos, Shay Soker. Development of a living biobank of breast cancer organoids [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 164.