Epidermal Growth Factor Tyrosine Kinase Research Articles

Abstract 1866: Discovery of mutation-independent EGFR degrading bispecific antibodies that suppress tumor growth in preclinical tumor models

Abstract Extracellular targeted protein degradation (eTPD) has emerged as a promising new drug modality focused on targeted elimination of extracellular and transmembrane proteins. In contrast to intracellular protein degraders, such as proteolysis targeting chimeras (PROTACs) and molecular glues which require ubiquitin-proteosome cellular degradation pathways, extracellular protein degraders can additionally harness endosomal-lysosomal protein degradation. Two recently published examples of extracellular protein degraders include AbTACs (antibody-based PROTAC) which co-engage a protein of interest (POI) and transmembrane E3 ligases, and KineTACs (cytokine receptor-targeting chimeras) which utilize endogenous cytokine receptors to degrade extracellular POIs. These bispecific antibody degrader platforms not only have advantageous pharmacological and drug-like manufacturing properties, but can also be engineered for tissue-specificity and to address multiple complementary targets, with the goal of increased efficacy and decreased toxicity. To that end, we have greatly expanded the extracellular degrader repertoire beyond AbTACs and KineTACs, with a novel bispecific antibody degrader platform called TrainTACs (tissue receptor antigen internalization targeting chimeras). To demonstrate the potential of this novel extracellular degrading platform, we developed degraders for the canonical receptor tyrosine kinase epidermal growth factor receptor (EGFR). EGFR is an oncogenic driver, that has been clinically validated in lung, colorectal and head and neck cancers, but patient benefit has been limited by treatment-related acquired resistance mutations and on-target/off-tumor dose-limiting toxicities. The potential of our TrainTACs, AbTACs and KineTACs to overcome the limitations of current therapeutic modalities was assessed. Gene expression profiles from tumor and normal tissues were evaluated to identify potential degraders co-expressed with EGFR in tumors. More than 70 unique bispecific antibody constructs spanning 20 receptors were generated and screened in tumor cell-based assays to evaluate EGFR antagonism, internalization, and degradation. TrainTACs, AbTACs and KineTACs degraded EGFR in multiple tumor cell lines covering a range of EGFR mutations. Degradation of EGFR led to deep inhibition of EGFR signaling, robust inhibitory effects on tumor spheroids, and in xenograft mouse tumor models. In conclusion, eTPD represents a promising new drug modality, and TrainTACs, AbTACs and KineTACs have expanded the toolbox of extracellular targeted protein degraders that can be utilized in a target-, tissue- and disease-specific manner. Citation Format: Jonathan Sitrin, Lisa Marshall, Hai Tran, Kenneth Ng, Kimberly Hoi, Josef Gramespacher, Zhong Huang, Andy Goodrich, Filomena Housley, May Dayao, Man-Tzu Wang, Katarina Pance, Aleysha Chen, Kevin Carlin, Lichao Zhang, James Lee, Rami Hannoush, Ken Flanagan, Maia Vinogradova, Isaac Rondon, Shyra Gardai. Discovery of mutation-independent EGFR degrading bispecific antibodies that suppress tumor growth in preclinical tumor models [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 1866.

IMesCuCl/TBHP system for aqueous oxidative amidation: Synthesis of new amide derivatives as EGFR targeting anti-breast cancer agents and computational studies

A base free and aqueous synthesis of some new 1,4-benzoxazinone-tetrazole containing amides via tert‑butyl hydroperoxide (TBHP) mediated oxidative coupling of 2-(5-(2-(3-oxo-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)ethyl)-2H-tetrazol-2-yl)acetaldehyde (10) with anilines (11a-n) under (1,3-dimesityl-2,3-dihydro-1H-imidazol-2-yl)copper(I) chloride (IMesCuCl) catalysis was reported herein for the first time. All these compounds (12a-n) were screened for their in vitro anti-breast cancer activity against two human breast cancer cell lines (MDA-MB-231 and MCF-7). Out of all, compound 12g showed greater activity than the Erlotinib on two cell lines with IC50 values in the range of 4.12–7.03 μg/mL. As well, compounds 12a and 12c showed greater activity than the Erlotinib on MCF-7 with IC50 values <4.5 μg/mL. The tyrosine kinase Epidermal Growth Factor Receptor (EGFR) inhibition studies revealed that compound 12g showed almost similar potency (IC50 = 0.47 μM) with the Erlotinib (IC50 = 0.41μM). Molecular docking studies revealed that compounds 12a, 12c and 12g showed encouraging binding energies and inhibition constants on EGFR (PDB ID-4HJO) than the Erlotinib. Finally, the most potent compound 12g was characterized by density functional theory (DFT) with B3LYP/6–311++ G (d, p) basis set. The structural parameters were obtained from geometry optimization. Molecular electrostatic potential (MEP) and highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gap and Mulliken atomic charges were calculated.

Abstract 12757: Osimertinib-Associated Cardiotoxicity: Insights Into Echocardiographic Changes and Patients at Increased Risk

Introduction: Osimertinib is a third-generation epidermal growth factor (EGFR) tyrosine kinase inhibitor used in the treatment of EGFR-mutant non-small cell lung cancer (NSCLC). While osimertinib has known cardiotoxicity risks, there is a paucity of detailed transthoracic echocardiographic (TTE) changes and known predictors. Hypothesis: Osimertinib is associated with TTE changes other than reduced EF in patients with NSCLC; further, those with pre-existing cardiac risk factors may be at increased risk of cardiotoxicity. Methods: Single-center retrospective analysis of patients with NSCLC with available TTEs after starting osimertinib between 2007-2022. Cardiac event (any grade ≥2 cardiac common terminology criteria for adverse events [CTCAE]) cumulative incidence was estimated and Fine and Gray regressions performed (adjusting for non-cardiac death as a competing risk). Results: In total, 85 patients were included (mean age was 68 years, 67% female). Median interval between osimertinib initiation and first follow-up TTE was 17.6 months. After a median follow-up of 35 months, 17 patients developed grade ≥2 CTCAE (2-year cumulative incidence, 19.2%; 95% confidence interval [CI]: 11%-29%). These CTCAEs include QTc prolongation (n = 10), EF decline of ≤50% or ≥10% drop from baseline (n = 5), new valvular regurgitation/stenosis on imaging (n = 5), and supraventricular arrhythmia (n = 3). A pre-treatment TTE was available for 38 patients prior to osimertinib initiation. Comparing post- vs pre-osimertinib TTEs, there was significant LVEF decline (58 ± 11% vs 61 ± 8%), increased diastolic dysfunction (40% vs 32%, mitral regurgitation (49% vs 24%), and tricuspid regurgitation (45% vs 24%), all p &lt;0.01. On multivariable analysis, preexisting arrhythmias (hazard ratio [HR] 3.90; 95% CI 1.11-1.13; p = 0.034) and BMI (HR 1.07, 95% CI 1.00-1.14; p = 0.04) were associated with an increased risk of cardiac events. Conclusions: Osimertinib was associated with a nearly 20% 2-year cumulative incidence of cardiac events and multiple echocardiographic changes. BMI is a potential modifiable risk factor to mitigate Osimertinib-associated cardiac events. These findings highlight the need for close surveillance in these higher cardiac-risk patients with NSCLC.

Designing and In silico Studies of Novel Hybrid of 1,3,4-oxadiazole-chalcone Derivatives as EGFR Inhibitors.

The tyrosine kinase epidermal growth factor receptor (TK-EGFR) has recently been identified as a useful target for anticancer treatments. The major concern for current EGFR inhibitors is resistance due to mutation, which can be overcome by combining more than one pharmacophore into a single molecule. In the present study, various hybrids of 1,3,4-oxadiazole-chalcone derivatives were gauged for their EGFR inhibitory potential. The design of 1,3,4-oxadiazole-chalcone hybrid derivatives was carried out and in-silico studies, viz., molecular docking, ADME, toxicity, and molecular simulation, were performed as EGFR inhibitors. Twenty-six 1,3,4-oxadiazole-chalcone hybrid derivatives were designed using the combi-lib tool of the V life software. AutoDock Vina software was used to perform in silico docking studies, while SwissADME and pkCSM tools were used to analyse molecules for ADME and toxicity. Desmond software was used to run the molecular simulation. Around 50% of molecules have shown better binding affinity as compared to standard and co-crystallized ligands. Molecule 11 was found to be a lead molecule that has the highest binding affinity, good pharmacokinetics, good toxicity estimates and better protein-ligand stability.

3D-QSAR and Molecular Docking Studies of Pyrimidine-based EGFR Inhibitors

Abstract: Epidermal growth factor tyrosine kinase receptor (EGFR) is expressed in a variety of tumors and has become a new target for anti-cancer drugs. In recent years, small molecule inhibitors targeting EGFR have been reported extensively. In this study, the structure–activity relationship of 119 pyrimidine EGFR inhibitors were studied based on comparative field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMISA). Performant models with high predictive ability were constructed (CoMFA model: q2 = 0.574, r 2 = 0.970, SEE = 0.163, F = 407.252; CoMSIA model: q2 = 0.575, r 2 = 0.968, SEE = 0.171, F = 286.102), according to which 9 new EGFR inhibitors were designed. MD simulation (100 ns) on the docked complex of compound N7 (the most active compound) shows that the small molecule binds with the protein stably. MM/PBSA calculation provided the binding free energy of the compound N7, -37.18 kcal·mol-1, lower than the original ligand. Newly designed molecules showed promising results in ADMET prediction. These results will provide valuable guidance for the design of novel EGFR inhibitors

Coumarin-Piperazine Tethered 1,2,3-Triazoles: EGFR Targeting Anti-Breast Cancer Evaluation and Molecular Docking Studies

We synthesized a new series of coumarin-piperazine 1,2,3-triazole hybrids (7a–7n) and screened for their in vitro anti-breast cancer activity against MCF-7, MDA-MB-468, and MDA-MB-231 cancer cell lines. The results revealed that compound 7f showed superior activity against all cell lines than the standard drug 5-fluorouracil. As well, compounds 7e, 7h, and 7k showed greater activity against MCF-7 than the positive control. Furthermore, 7f and 7h showed higher potency in inhibiting tyrosine kinase epidermal growth factor receptor (EGFR) than the standard drug erlotinib. Finally, in silico molecular docking studies on EGFR (PDB ID-4HJO) revealed that compounds 7e, 7f, 7h, and 7k possess good binding energies and inhibition constants as compared to erlotinib.

Coevolution-based computational approach to detect resistance mechanism of epidermal growth factor receptor

Tyrosine kinase epidermal growth factor receptor (EGFR) correlates the neoplastic cell metastasis, angiogenesis, neoplastic incursion, and apoptosis. Due to the involvement of EGFR in these biological processes, it becomes a most potent target for treating non-small cell lung cancer (NSCLC). The tyrosine kinase inhibitors (TKI) have endorsed high efficacy and anticipation to patients but unfortunately, within a year of treatment, drug targets develop resistance due to mutations. The present study detected the compensatory mutations in EGFR to know the evolutionary mechanism of drug resistance. The results of this study demonstrate that compensatory mutations enlarge the drug-binding pocket which may lead to the altered orientation of the ligand (gefitinib and erlotinib) causing drug resistance. This indicates that coevolutionary forces play a significant role in fine-tuning the structure of EGFR protein against the drugs. The analysis provides insight into the evolution-induced structural aspects of drug resistance changes in EGFR which in turn be useful in designing drugs with better efficacy.

Organocatalytic [3+2] Cycloaddition Reaction: Synthesis of Fully Decorated Sulfonyl 1,2,3‐Triazoles as Potent EGFR Targeting Anticancer Agents**

AbstractA general strategy was developed for the synthesis of new fully decorated sulfonyl1,2,3‐triazolyl imidazoles from β‐ketosulfones and several aryl sulfonyl azides using the ramachary organocatalytic cycloaddition method. Organocatalytic [3+2] cycloaddition reaction of β‐ketosulfone acts as an internal alkyne, as reported for the synthesis of sulfonyl‐1,2,3‐triazolyl imidazoles at 80 °C in good to excellent yields of products in the presence of catalytic amounts of pyrrolidine (10 mol %). In vitro anticancer activity of all these derivatives revealed that four compounds like 4‐((5‐(4‐methoxyphenyl)‐4‐((1‐methyl‐1H‐imidazol‐2‐yl) sulfonyl)‐1H‐1,2,3‐triazol‐1‐yl)sulfonyl) benzonitrile, 5‐(4‐methoxyphenyl)‐4‐((1‐methyl‐1H‐imidazol‐2‐yl)sulfonyl)‐1‐((4‐nitro phenyl) sulfonyl)‐1H‐1,2,3‐triazole,4‐((4‐((1‐methyl‐1H‐imidazol‐2‐yl) sulfonyl)‐5‐(4‐nitrophenyl)‐1H‐1,2,3‐triazol‐1‐yl)sulfonyl)benzonitrile, and 1‐((4‐chlorophenyl)sulfonyl)‐4‐((1‐methyl‐1H‐imidazol‐2‐yl) sulfonyl)‐5‐(4‐nitrophenyl)‐1H‐1,2,3‐triazole was active against three human cancer cell lines: MCF‐7, MDA‐MB‐231, and A‐549. Later, the results of the inhibitory assay of potent compounds against the tyrosine kinase epidermal growth factor receptor revealed that compounds 1‐((4‐chlorophenyl)sulfonyl)‐5‐(4‐methoxyphenyl)‐4‐((1‐methyl‐1H‐imidazol‐2‐yl)sulfonyl)‐1H‐1,2,3‐triazole and 1‐((4‐chlorophenyl) sulfonyl)‐4‐((1‐methyl‐1H‐imidazol‐2‐yl) sulfonyl)‐5‐(4‐nitrophenyl)‐1H‐1,2,3‐triazole showed more potency than the reference drug erlotinib.

EGF, TGF-α and Amphiregulin Differently Regulate Endometrium-Derived Mesenchymal Stromal/Stem Cells.

The prototypical receptor tyrosine kinase epidermal growth factor receptor (EGFR) is regulated by a set of its ligands, which determines the specificity of signaling and intracellular fate of the receptor. The EGFR signaling system is well characterized in immortalized cell lines such as HeLa derived from tumor tissues, but much less is known about EGFR function in untransformed multipotent stromal/stem cells (MSCs). We compared the effect of epidermal growth factor (EGF), transforming growth factor-α (TGF-α) and amphiregulin (AREG) on physiological responses in endometrial MSCs (enMSC) and HeLa cells. In addition, using Western blotting and confocal microscopy, we studied the internalization and degradation of EGFR stimulated by the three ligands in these cell lines. We demonstrated that unlike HeLa, EGF and TGF-α, but not AREG, stimulated enMSC proliferation and prevented decidual differentiation in an EGFR-dependent manner. In HeLa cells, EGF targeted EGFR for degradation, while TGF-α stimulated its recycling. Surprisingly, in enMSC, both ligands caused EGFR degradation. In both cell lines, AREG-EGFR internalization was not registered. In HeLa cells, EGFR was degraded within 2 h, restoring its level in 24 h, while in enMSC, degradation took more than 4-8 h, and the low EGFR level persisted for several days. This indicates that EGFR homeostasis in MSCs may differ significantly from that in immortalized cell lines.

Synthesis and biological evaluation of pyrido[3,2,1-ij][1,2,3]triazolo[4,5-c] quinolinones: PEG-400 mediated one-pot reaction under ultrasonic irradiation

A general strategy was developed for the synthesis of fused pyrido[3,2,1-ij] [1–3]triazolo[4,5-c]quinolinones from 1-(3-iodoprop-2-yn-1-yl)-4-methylquinolin-2(1H)-one and several azides using ultrasound irradiation in PEG-400 medium. In vitro anticancer activity of all these derivatives against MCF-7 (breast) and A-549 (alveolar carcinoma) cancer cell lines using the MTT assay. Among all the tested compounds, 4e, 4f, and 4j displayed remarkable cytotoxic activity against both cancer cell lines as compared to the remaining compounds. In specific, compound 4f showed superior activity against A-549 cell lines than the standard drug Erlotinib. Later, the results of inhibitory assay of potent compounds 4e, 4f, and 4j against the tyrosine kinase epidermal growth factor receptor (EGFR) revealed that compound 4f shows equipotent activity of the reference drug erlotinib.

T Cells in Colorectal Cancer: Unravelling the Function of Different T Cell Subsets in the Tumor Microenvironment.

Therapeutic options for metastatic colorectal cancer (mCRC) are very limited, and the prognosis using combination therapy with a chemotherapeutic drug and a targeted agent, e.g., epidermal growth factor receptor or tyrosine kinase, remains poor. Therefore, mCRC is associated with a poor median overall survival (mOS) of only 25-30 months. Current immunotherapies with checkpoint inhibitor blockade (ICB) have led to a substantial change in the treatment of several cancers, such as melanoma and non-small cell lung cancer. In CRC, ICB has only limited effects, except in patients with microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) tumors, which comprise about 15% of sporadic CRC patients and about 4% of patients with metastatic CRC. The vast majority of sporadic CRCs are microsatellite-stable (MSS) tumors with low levels of infiltrating immune cells, in which immunotherapy has no clinical benefit so far. Immunotherapy with checkpoint inhibitors requires the presence of infiltrating T cells into the tumor microenvironment (TME). This makes T cells the most important effector cells in the TME, as evidenced by the establishment of the immunoscore-a method to estimate the prognosis of CRC patients. The microenvironment of a tumor contains several types of T cells that are anti-tumorigenic, such as CD8+ T cells or pro-tumorigenic, such as regulatory T cells (Tregs) or T helper 17 (Th17) cells. However, even CD8+ T cells show marked heterogeneity, e.g., they can become exhausted, enter a state of hyporesponsiveness or become dysfunctional and express high levels of checkpoint molecules, the targets for ICB. To kill cancer cells, CD8+ T cells need the recognition of the MHC class I, which is often downregulated on colorectal cancer cells. In this case, a population of unconventional T cells with a γδ T cell receptor can overcome the limitations of the conventional CD8+ T cells with an αβT cell receptor. γδ T cells recognize antigens in an MHC-independent manner, thus acting as a bridge between innate and adaptive immunity. Here, we discuss the effects of different T cell subsets in colorectal cancer with a special emphasis on γδ T cells and the possibility of using them in CAR-T cell therapy. We explain T cell exclusion in microsatellite-stable colorectal cancer and the possibilities to overcome this exclusion to enable immunotherapy even in these "cold" tumors.

Organocatalytic [3 + 2] Cycloaddition Reaction: Synthesis of Fully Decorated Sulfonyl-1,2,3-Triazolyl Pyrimidines as Potent Anticancer and EGFR Inhibitors

A general strategy was developed for the synthesis of new fully decorated sulfonyl1,2,3-triazolyl pyrimidines (6a–6j and 8a–8f) from 2-((6-methyl-2-(methylsulfonyl)pyrimidin-4-yl)sulfonyl)-1-(4-nitrophenyl)ethanone and several azides in the presence of catalytic amounts of organocatalyst. Ramachary OrgAKC reaction of β-ketosulfone (4) acts as an internal alkyne as reported for the synthesis of sulfonyl-1,2,3-triazolyl pyrimidines at 80 °C in good to excellent yields of products in the presence of catalytic amounts of pyrrolidine (10 mol %). In vitro anticancer activity of all these derivatives revealed that six compounds like 6d, 6e, 6g, 6h, 8c, and 8d were active against three human cancer cell lines like breast carcinoma, cervical carcinoma, and alveolar carcinoma. In specific, compounds 6g and 6h showed superior activity against tested cell lines compared to the standard drug erlotinib. Later, the results of inhibitory assay of potent compounds 6d, 6e, 6g, 6h, 8c, and 8d against the tyrosine kinase epidermal growth factor receptor (EGFR) revealed that compounds 6g and 6h showed more potency than the reference drug erlotinib.

NOTCH4ΔL12_16 sensitizes lung adenocarcinomas to EGFR-TKIs through transcriptional down-regulation of HES1

Resistance to epidermal growth factor tyrosine kinase inhibitors (EGFR-TKI) remains one of the major challenges in lung adenocarcinoma (LUAD) therapy. Here, we find an increased frequency of the L12_16 amino acid deletion mutation in the signal peptide region of NOTCH4 (NOTCH4ΔL12_16) in EGFR-TKI-sensitive patients. Functionally, exogenous induction of NOTCH4ΔL12_16 in EGFR-TKI -resistant LUAD cells sensitizes them to EGFR-TKIs. This process is mainly mediated by the reduction of the intracellular domain of NOTCH4 (NICD4) caused by the NOTCH4ΔL12_16 mutation, which results in a lower localization of NOTCH4 in the plasma membrane. Mechanistically, NICD4 transcriptionally upregulates the expression of HES1 by competitively binding to the gene promoter relative to p-STAT3. Because p-STAT3 can downregulate the expression of HES1 in EGFR-TKI-resistant LUAD cells, the reduction of NICD4 induced by NOTCH4ΔL12_16 mutation leads to a decrease in HES1. Moreover, inhibition of the NOTCH4-HES1 pathway using inhibitors and siRNAs abolishes the resistance of EGFR-TKI. Overall, we report that the NOTCH4ΔL12_16 mutation sensitizes LUAD patients to EGFR-TKIs through transcriptional down-regulation of HES1 and that targeted blockade of this signaling cohort could reverse EGFR-TKI -resistance in LUAD, providing a potential approach to overcome resistance to EGFR-TKI -therapy.

Synthesis, docking and evaluation of novel fused pyrimidine compounds as possible lead compounds with antibacterial and antitumor activities.

Reaction of a series of hydrazonoyl chlorides with substituted aminopyrimidines afforded good selectivity in most cases leading either to formation of new imidazo[1,2-a]pyrimidine derivatives, or regioisomeric hydrazonamide adducts. The compounds were evaluated for antibacterial and anticancer activities. Screening against E. Coli, P. aeruginosa, S. aureus, S. epidermidis, B. subtilis and K. rhizophila did identify several different compound types with MIC of 0.1-0.4 mg/mL. Anticancer evaluation against a HeLa cell line identified one imidazo[1,2-a]pyrimidine lead. An in silico target fishing analysis suggest three possible high value protein targets, Tankyrase-2 (Tank-2), Cyclin-dependent kinase (CDK2) and Epidermal growth factor tyrosine kinase receptor (EGFR), with modelling fit against co-crystallized known ligands. This provides a new structural family lead for further investigation of molecular targets and potential SAR activity development.

Novel CDK12/13 Inhibitors AU-15506 and AU-16770 Are Potent Anti-Cancer Agents in EGFR Mutant Lung Adenocarcinoma with and without Osimertinib Resistance.

Osimertinib is a third-generation epidermal growth factor receptor and tyrosine kinase inhibitor (EGFR-TKI) approved for the treatment of lung adenocarcinoma patients harboring EGFR mutations. However, acquired resistance to this targeted therapy is inevitable, leading to disease relapse within a few years. Therefore, understanding the molecular mechanisms of osimertinib resistance and identifying novel targets to overcome such resistance are unmet needs of cancer patients. Here, we investigated the efficacy of two novel CDK12/13 inhibitors, AU-15506 and AU-16770, in osimertinib-resistant EGFR mutant lung adenocarcinoma cells in culture and xenograft models in vivo. We demonstrate that these drugs, either alone or in combination with osimertinib, are potent inhibitors of osimertinib-resistant as well as -sensitive lung adenocarcinoma cells in culture. Interestingly, only the CDK12/13 inhibitor in combination with osimertinib, although not as monotherapy, suppresses the growth of resistant tumors in xenograft models in vivo. Taken together, the results of this study suggest that inhibition of CDK12/13 in combination with osimertinib has the potential to overcome osimertinib resistance in EGFR mutant lung adenocarcinoma patients.

Abstract 2551: CASC4 drives anoikis resistance in high grade serous ovarian cancer through recycling of EGFR

Abstract Introduction: Ovarian cancer is the deadliest gynecological malignancy, and accounts for over 150,000 deaths per year worldwide. The high grade serous ovarian cancer (HGSOC) subtype accounts for almost 60% of ovarian cancers and is the deadliest. HGSOC originates in the fimbria of the fallopian tube and disseminates through the peritoneal cavity. Survival of tumor cells in the peritoneal fluid requires cells to resist anoikis (anchorage-independent apoptosis). CRISPR/Cas9 and transcriptomic screens identified the Golgi protein CASC4 (GOLM2, H63) as a “driver” of anoikis resistance. As CASC4 is highly uncharacterized in literature, we sought to determine how CASC4 confers anoikis resistance to HGSOC cells. Methods: Mining of publicly available ovarian cancer datasets (TCGA) showed that CASC4 is associated with worse clinical outcomes, such as worse overall survival and increased resistance to platinum-based chemotherapies. For experiments, we used HGSOC cell lines PEO1, CaOV3, and OVCAR3 with shRNA-mediated CASC4 knockdowns (CASC4 KD), cultured in forced suspension. Results: Culturing cells in suspension, to recapitulate the peritoneal fluid environment in vitro, showed that CASC4 KD hampers cell proliferation and colony formation ability, and increases apoptosis. Additionally, a Reverse Phase Protein Assay (RPPA) showed that CASC4 KD results in significant changes in proteins known to be localized to the cell surface or secreted, including decreased protein levels of the receptor tyrosine kinase (RTK) Epidermal Growth Factor Receptor (EGFR), an initiator of several oncogenic signaling pathways. A paralog of CASC4, GOLM1, is known to drive hepatocellular carcinoma through various mechanisms, such as the recycling of internalized RTKs, including EGFR. Indeed, our experiments showed that CASC4 KD in ovarian cancer cells leads to decreased EGFR levels and decreased EGFR recycling. Conclusion: Knocking down CASC4 results in decreased survivability in suspension, decreased EGFR levels at the plasma membrane, and decreased recycling of EGFR. Further elucidating mechanisms of CASC4-dependent anoikis resistance could lead to the development of novel therapeutic approaches, such as inhibitory peptides, and may assist in developing newer biomarkers for predicting ovarian cancer malignancy. Citation Format: Jaidev Bapat, Lindsay W. Brubaker, Zachary L. Watson, Tomomi M. Yamamoto, Benjamin G. Bitler. CASC4 drives anoikis resistance in high grade serous ovarian cancer through recycling of EGFR [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 2551.

Salicylanilides and Their Anticancer Properties.

Salicylanilides are pharmacologically active compounds with a wide spectrum of biological effects. Halogenated salicylanilides, which have been used for decades in human and veterinary medicine as anthelmintics, have recently emerged as candidates for drug repurposing in oncology. The most prominent example of salicylanilide anthelmintic, that is intensively studied for its potential anticancer properties, is niclosamide. Nevertheless, recent studies have discovered extensive anticancer potential in a number of other salicylanilides. This potential of their anticancer action is mediated most likely by diverse mechanisms of action such as uncoupling of oxidative phosphorylation, inhibition of protein tyrosine kinase epidermal growth factor receptor, modulation of different signaling pathways as Wnt/β-catenin, mTORC1, STAT3, NF-κB and Notch signaling pathways or induction of B-Raf V600E inhibition. Here we provide a comprehensive overview of the current knowledge about the proposed mechanisms of action of anticancer activity of salicylanilides based on preclinical in vitro and in vivo studies, or structural requirements for such an activity.

Identification of a novel peptide ligand for the cancer-specific receptor mutation EGFRvIII using high-throughput sequencing of phage-selected peptides

We report here the selection and characterization of a novel peptide ligand using phage display targeted against the cancer-specific epidermal growth factor tyrosine kinase receptor mutation variant III (EGFRvIII). This receptor is expressed in several kinds of cancer: ovarian cancer, breast cancer and glioblastoma, but not in normal tissues. A 12-mer random peptide library was screened against EGFRvIII. Phage-selected peptides were sequenced in high-throughput by next generation sequencing (NGS), and their diversity was studied to identify highly abundant clones expected to bind with the highest affinities to EGFRvIII. The enriched peptides were characterized and their binding capacity towards stable cell lines expressing EGFRvIII, EGFR wild type (EGFR WT), or a low endogenous level of EGFR WT was confirmed by flow cytometry analysis. The best peptide candidate, VLGREEWSTSYW, was synthesized, and its binding specificity towards EGFRvIII was validated in vitro. Additionally, computational docking analysis suggested that the identified peptide binds selectively to EGFRvIII. The novel VLGREEWSTSYW peptide is thus a promising EGFRvIII-targeting agent for future applications in cancer diagnosis and therapy.

Undertreatment with Osimertinib in patient with multiple chemical sensitivity. A case report.

Multiple chemical sensitivity (MCS), is a syndrome characterised by increased sensitivity to the exposure of environmental chemicals (1). There are considerable difficulties in reaching a good estimate of the prevalence of disease and the main pathogenetic hypotheses take into account both the organic and psychiatric/psychological factors. Treatment with epidermal growth factor tyrosine kinase receptor inhibitors (tkis), like Osimertinib, results in improved progression-free survival (PFS) compared to chemotherapy, in Non-small-cell lung carcinoma (NSCLC) with epidermal growth factor receptor (EGFR) mutation (2). We describe the case of a 74 year old woman with history of MCS and fibromyalgia in treatment with Osimertinib for EGFR-mutated NSCLC. Patient initially refused any form of active therapy for lung cancer, but thanks to teamwork and the important support of the psychologist, the patient decided to start treatment with Osimertinib at a reduced dose, not 80 mg but 40 mg. Subsequently, after few days , of his own free will and without informing the staff physicians, the patient changed the treatment schedule by taking one quarter of the dose of the medicine every other day, justifying this choice in therapeutic modification because of her fear and intolerance to any type of medicine and/ or chemical substance, being influenced by MCS. Despite the changes in the treatment plan, a PET scan performed after two months showed a sigificative lung response and the stability of bone metastases. Discussion. Our case describes a significative response with Osimertinib despite the change in dosage and schedule in a patient with MCS. Our experience deserves to be considered in the light of its particularity and uniqueness as it shows an excellent response to treatment with Osimertinib despite the change made to the dosage and schedule, in a patient presenting in her medical history this rare pathological condition: MCS syndrome.

DFT Investigation, Hirshfield Analysis and Molecular Docking of Cu(II) Complex of O‐Vanillin Based Ligand

AbstractIn this work, electronic structure and intermolecular interaction of a literature reported, biologically active Cu(II) complex comprising of a Schiff base ligand containing o‐vanillin and 2‐aminothiazole moieties is presented. Hirshfeld surface analysis is performed to comprehend the close contacts between two neighbouring molecules. The geometry of the complex is optimized using Density Functional Theory. Further, HOMO and LUMO energies, chemical reactivity parameters and molecular electrostatic potential (MEP) are investigated. The interaction energy calculation from Hirshfeld surface analysis indicates that the complex is stabilized by dispersion energy which is major contributing factor in stabilizing the complex. The intermolecular interaction in the complex having 57 % contribution from H−H interaction. To investigate the anticancer potential of the complex, binding studies with Epidermal Growth Factor Receptor(EGFR) and Tyrosine Kinase (TRK) receptor was performed by molecular docking analysis. Complex has shown good free energy of binding against both the target molecules which is −11.71&amp;−10.56 Kcal/mol respectively along with significant inhibition constant. The mode of interaction is predominantly hydrogen bonding, hydrophobic interactions along with a few salt bridges. These results predict excellent anticancer potential of this category of metal complexes.