Construction of a novel cell-based assay for the evaluation of anti-EGFR drug efficacy against EGFR mutation

Multimodal scanning of genetic variants with base and prime editing

Mutational scanning connects genetic variants to phenotype, enabling the interrogation of protein functions, interactions and variant pathogenicity. However, current methodologies cannot efficiently engineer customizable sets of diverse genetic variants in endogenous loci across cellular contexts in high throughput. Here, we combine cytosine and adenine base editors and a prime editor to assess the pathogenicity of a broad spectrum of variants in the epithelial growth factor receptor gene (EGFR). Using pooled base editing and prime editing guide RNA libraries, we install tens of thousands of variants spanning the full coding sequence of EGFR in multiple cell lines and assess the role of these variants in tumorigenesis and resistance to tyrosine kinase inhibitors. Our EGFR variant scan identifies important hits, supporting the robustness of the approach and revealing underappreciated routes to EGFR activation and drug response. We anticipate that multimodal precision mutational scanning can be applied broadly to characterize genetic variation in any genetic element of interest at high and single-nucleotide resolution.

Erlotinib regulates short-term memory, tau/Aβ pathology, and astrogliosis in mouse models of AD

Introduction

Erlotinib is an epidermal growth factor receptor (EGFR) inhibitor that is approved by the FDA to treat non-small cell lung cancer (NSCLC). Several membrane receptors, including EGFR, interact with amyloid β (Aβ), raising the possibility that erlotinib could have therapeutic effects on Alzheimer's disease (AD). However, the effects of erlotinib on Aβ/tau-related pathology and cognitive function in mouse models of AD and its mechanisms of action have not been examined in detail.

Methods

To investigate the effects of erlotinib on cognitive function and AD pathology, 3 to 6-month-old PS19 mice and 3 to 3.5-month-old 5xFAD mice and WT mice were injected with vehicle (5% DMSO + 10% PEG + 20% Tween80 + 65% D.W.) or erlotinib (20 mg/kg, i.p.) daily for 14 or 21 days. Then, behavioral tests, Golgi staining, immunofluorescence staining, western blotting ELISA, and real-time PCR were conducted.

Results and discussion

We found that erlotinib significantly enhanced short-term spatial memory and dendritic spine formation in 6-month-old P301S tau transgenic (PS19) mice. Importantly, erlotinib administration reduced tau phosphorylation at Ser202/Thr205 (AT8) and Thr231 (AT180) and further aggregation of tau into paired helical fragments (PHFs) and neurofibrillary tangles (NFTs) in 3-month-old and/or 6-month-old PS19 mice by suppressing the expression of the tau kinase DYRK1A. Moreover, erlotinib treatment decreased astrogliosis in 6-month-old PS19 mice and reduced proinflammatory responses in primary astrocytes (PACs) from PS19 mice. In 3- to 3.5-month-old 5xFAD mice, erlotinib treatment improved short-term spatial memory and hippocampal dendritic spine number and diminished Aβ plaque deposition and tau hyperphosphorylation. Furthermore, erlotinib-treated 5xFAD mice exhibited significant downregulation of astrocyte activation, and treating PACs from 5xFAD mice with erlotinib markedly reduced cxcl10 (reactive astrocyte marker) and gbp2 (A1 astrocyte marker) mRNA levels and proinflammatory cytokine mRNA and protein levels. Taken together, our results suggest that erlotinib regulates tau/Aβ-induced AD pathology, cognitive function, and Aβ/tau-evoked astrogliosis and therefore could be a potent therapeutic drug for ameliorating AD symptoms.

Effects of N361 Glycosylation on Epidermal Growth Factor Receptor Biological Function

Epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase that is frequently modified by glycosylation post-translationally. In cancer, EGFR amplifications and hotspot mutations such as L858R that promote proliferation have been detected in a significant fraction of non-small cell lung carcinomas and breast adenocarcinomas. Molecular dynamic simulations suggested that glycosylation at asparagine residue 361 (N361) promotes dimerization and ligand binding. We stably expressed glycosylation-deficient mutant EGFR N361A, with or without the oncogenic mutation L858R. Immunofluorescence and flow cytometry demonstrated that the mutants were each well expressed at the cell membrane. N361A decreased proliferation relative to wild-type EGFR as well as decreased sensitivity to ligands. Proximity ligation assays measuring co-localization of EGFR with its binding partner HER2 in cells revealed that N361A mutations increased co-localization. N361A, located near the binding interface for the EGFR inhibitor necitumumab, desensitized cells expressing the oncogenic EGFR L858R to antibody-based inhibition. These findings underline the critical relevance of post-translational modifications on oncogene function.

The cell line models to study tyrosine kinase inhibitors in non-small cell lung cancer with mutations in the epidermal growth factor receptor: A scoping review

Non-Small Cell Lung Cancer (NSCLC) represents ∼85% of all lung cancers and ∼15-20% of them are characterized by mutations affecting the Epidermal Growth Factor Receptor (EGFR). For several years now, a class of tyrosine kinase inhibitors was developed, targeting sensitive mutations affecting the EGFR (EGFR-TKIs). To date, the main burden of the TKIs employment is due to the onset of resistance mutations. This scoping review aims to resume the current situation about the cell line models employed for the in vitro evaluation of resistance mechanisms induced by EGFR-TKIs in oncogene-addicted NSCLC. Adenocarcinoma results the most studied NSCLC histotype with the H1650, H1975, HCC827 and PC9 mutated cell lines, while Gefitinib and Osimertinib the most investigated inhibitors. Overall, data collected frame the current advancement of this topic, showing a plethora of approaches pursued to overcome the TKIs resistance, from RNA-mediated strategies to the innovative combination therapies.

Lung cancer organoids: models for preclinical research and precision medicine

Lung cancer is a malignancy with high incidence and mortality rates globally, and it has a 5-year survival rate of only 10%-20%. The significant heterogeneity in clinical presentation, histological features, multi-omics findings, and drug sensitivity among different lung cancer patients necessitate the development of personalized treatment strategies. The current precision medicine for lung cancer, primarily based on pathological and genomic multi-omics testing, fails to meet the needs of patients with clinically refractory lung cancer. Lung cancer organoids (LCOs) are derived from tumor cells within tumor tissues and are generated through three-dimensional tissue culture, enabling them to faithfully recapitulate in vivo tumor characteristics and heterogeneity. The establishment of a series of LCOs biobanks offers promising platforms for efficient screening and identification of novel targets for anti-tumor drug discovery. Moreover, LCOs provide supplementary decision-making factors to enhance the current precision medicine for lung cancer, thereby addressing the limitations associated with pathology-guided approaches in managing refractory lung cancer. This article presents a comprehensive review on the construction methods and potential applications of LCOs in both preclinical and clinical research. It highlights the significance of LCOs in biomarker exploration, drug resistance investigation, target identification, clinical precision drug screening, as well as microfluidic technology-based high-throughput drug screening strategies. Additionally, it discusses the current limitations and future prospects of this field.

TAS2940, a novel brain-penetrable pan-ERBB inhibitor, for tumors with HER2 and EGFR aberrations

Genetic alterations in human epidermal growth factor receptor type 2 (HER2)/epidermal growth factor receptor (EGFR) are commonly associated with breast and lung cancers and glioblastomas. Cancers with avian erythroblastosis oncogene B (ERBB) deregulation are highly metastatic and can cause primary brain tumors. Currently, no pan-ERBB inhibitor with remarkable brain penetration is available. Here, TAS2940, a novel irreversible pan-ERBB inhibitor with improved brain penetrability, was evaluated for its efficacy against several ERBB aberrant cancer models. The selectivity of TAS2940 was evaluated by enzymatic kinase assays. The inhibitory effects of TAS2940 against ERBB genetic alterations were examined using MCF10A cells expressing various HER2 or EGFR mutations and other generic cell lines harboring deregulated ERBB expression. In vivo efficacy of TAS2940 was examined following oral treatment in subcutaneous or intracranial xenograft cancer models. TAS2940 was highly potent against cells harboring HER2/EGFR alterations. TAS2940 could selectively inhibit phosphorylation of targets and the growth of cancer cells with ERBB aberrations in vitro. TAS2940 also inhibited tumor growth in xenograft mouse models with ERBB aberrations: HER2 amplification, HER2/EGFR exon 20 insertions, and EGFR vIII mutation. TAS2940 was effective in the intracranial xenograft models of HER2/EGFR cancers and improved the survival of these mice. TAS2940 has promising therapeutic effects in preclinical study against cancers harboring HER2/EGFR mutations, especially metastatic and primary brain tumors. Our results highlight potential novel strategies against lung cancers with brain metastases harboring HER2/EGFR exon 20 insertions and glioblastomas with EGFR aberrations.

Characteristics of clinical trials for non-small cell lung cancer therapeutic vaccines registered on ClinicalTrials.gov

Background

Even after complete surgical treatment or chemotherapy, Non-Small Cell Lung Cancer (NSCLC) patients are also at substantial risk for recurrence and spread trend. Therapeutic cancer vaccination could increase the anti-tumor immune response and prevent tumor relapse. This study aimed to assess the characteristics of NSCLC therapeutic vaccines registered on ClinicalTrials.gov.

Methods

We conducted a cross-sectional, descriptive study of clinical trials for Non-Small Cell Lung Cancer Therapeutic Vaccines Registered on ClinicalTrials.gov (https://clinicaltrials.gov/) through March 17, 2022.

Results

This study encompassed 117 registered trials included for data analysis. The number of trials was significantly correlated with a beginning year (r = 0.504, P < 0.010). Of these trials, 45.30% were completed, 12.82% were terminated, and 8.55% were withdrawn. More than half of trials (52.99%) were funded by industry, and more than half of trials (52.14%) were located in economically developed North America. Regarding study designs of these trials, 27.35% were randomized, 52.14% were single group assignment, 83.76% were without masking, 35.90% were phase 1, and more than half of the trials (56.41%) recruited less than 50 participants. The highest proportion of vaccine types was protein/peptide vaccines (41.88%). Regarding TNM staging, the highest proportion of the trials is stage III-IV (26.50%).

Conclusion

The number of clinical trials about the cancer therapeutic vaccines was sustained an increase in recent years. The main characteristic of clinical trials for NSCLC therapeutic vaccines is lack of randomized control, lack of mask, and recruiting less than 50 participants. In recent years, the protein/peptide vaccines for NSCLC active immunotherapy have been well studied.

In vitro cytotoxicity and docking study of novel symmetric and asymmetric dihydropyridines and pyridines as EGFR tyrosine kinase inhibitors

Quinolines have a weighty effect as anticancer agents and 1,4-DHPs have demonstrated efficacy as anticancer agents in several studies, as well. New hybrid models of symmetric and asymmetric 1,4-DHPs and pyridines linked at C₃ of 2-chloroquinoline as a new anticancer scaffold, were designed and synthesized. Hantszch 1,4-DHPs method was adopted for chemical synthesis. MTT assay was performed for the evaluation of cytotoxicity, and EGFR tyrosine kinase assay was performed to investigate binding to our selected compounds, measured by ELISA. The IC₅₀ expressed in µM values revealed that compounds 4a,b, and 5i,k showed the best results against the tested four cell lines than the reference drug 5-Flurouuracil. Compound 5k displayed the most potent cytotoxic activity with IC₅₀  values in the low µM range (12.03 ± 1.51: 20.09 ± 2.16 µM), compared with 5-Fu IC₅₀ range (40.74 ± 2.46: 63.81 ± 2.69 µM). The incorporation of 2-chloroquinoline at C₃ to C₄ of 1,4-DHP could be proposed as an anticancer scaffold rather than its analogous pyridines. Ester fragments connected to 1,4-DHPs ring as a lipophilic part are essential for anticancer activity. The chirality at C₄ improved the anticancer activity. The hydrogen and halogen bond facilitated protein-ligand binding mode and affinity.

Osteopontin improves sensitivity to tyrosine kinase inhibitor in lung adenocarcinoma in vitro by promoting epidermal growth factor receptor phosphorylation

PURPOSE

Tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptor (EGFR) improve the prognosis of lung adenocarcinoma (LUAD). However, the factors affecting its clinical efficacy remain unclear. This study aimed to determine the correlation between Osteopontin (OPN) and EGFR, and explore the inhibitory effect of first-generation TKI gefitinib on LUAD cells.

METHODS

The correlation between OPN and EGFR was determined through bioinformatics technology, and the clinical information as well as samples of related patients were collected to verify the relationship between them. Using three different NSCLC cell lines A549, H1299 and PC9, we studied the effects of OPN expression and EGFR phosphorylation on the first-generation TKI's efficacy in vitro.

RESULTS

Our data revealed that OPN staining positively linked to a more advanced clinical stage. Compared with the control group, LUAD cells with elevated OPN levels are more sensitive to the growth inhibitory effect of TKI. Knocking down of OPN decreased the response of cells to gefitinib. Besides, OPN also upregulated the phosphorylation of EGFR, thereby affecting the effect of TKI.

CONCLUSION

OPN enhanced the sensitivity of LUAD cells to gefitinib by promoting EGFR phosphorylation. OPN may be a potential target for evaluating TKI efficacy and a potential target for molecular therapy.

Total Synthesis and Structural Revision of Cyclotetrapeptide Asperterrestide A

The structural revision of cyclotetrapeptide asperterrestide A has been achieved based on total synthesis and molecular modeling. For these studies, (2 R,3 S)-MePhe(3-OH) and (2 S,3 S)-MePhe(3-OH) suitably protected for peptide synthesis were prepared via a stereoselective reduction of a ketone precursor derived from L- or d-serine, using L-selectride or DIBAL-H. The synthesis of the proposed structure of asperterrestide A (1a) was accomplished by solution-phase synthesis of a linear precursor followed by macrolactamization. The NMR spectra of our synthetic 1a were not identical to those reported for the natural compound. Molecular modeling studies suggested that the correct structure 1b was the one in which the stereochemistry at the α-positions of the Ala and MePhe(3-OH) residues is the opposite to that of the proposed structure. This was confirmed by the total synthesis of 1b and its subsequent structural characterization.

An In Vitro System for Evaluating Molecular Targeted Drugs Using Lung Patient-Derived Tumor Organoids

Patient-derived tumor organoids (PDOs) represent a promising preclinical cancer model that better replicates disease, compared with traditional cell culture models. We have established PDOs from various human tumors to accurately and efficiently recapitulate the tissue architecture and function. Molecular targeted therapies with remarkable efficacy are currently in use against various tumors. Thus, there is a need for in vitro functional-potency assays that can be used to test the efficacy of molecular targeted drugs and model complex interactions between immune cells and tumor cells to evaluate the potential for cancer immunotherapy. This study represents an in vitro evaluation of different classes of molecular targeted drugs, including small-molecule inhibitors, monoclonal antibodies, and an antibody-drug conjugate, using lung PDOs. We evaluated epidermal growth factor receptor and human epidermal growth factor receptor 2 (HER2) inhibitors using a suitable high-throughput assay system. Next, the antibody-dependent cellular cytotoxicity (ADCC) activity of an anti-HER2 monoclonal antibody was evaluated to visualize the interactions of immune cells with PDOs during ADCC responses. Moreover, an evaluation system was developed for the immune checkpoint inhibitors, nivolumab and pembrolizumab, using PDOs. Our results demonstrate that the in vitro assay systems using PDOs were suitable for evaluating molecular targeted drugs under conditions that better reflect pathological conditions.

TAS0728, A Covalent-binding, HER2-selective Kinase Inhibitor Shows Potent Antitumor Activity in Preclinical Models

Activated HER2 is a promising therapeutic target for various cancers. Although several reports have described HER2 inhibitors in development, no covalent-binding inhibitor selective for HER2 has been reported. Here, we report a novel compound TAS0728 that covalently binds to HER2 at C805 and selectively inhibits its kinase activity. Once TAS0728 bound to HER2 kinase, the inhibitory activity was not affected by a high ATP concentration. A kinome-wide biochemical panel and cellular assays established that TAS0728 possesses high specificity for HER2 over wild-type EGFR. Cellular pharmacodynamics assays using MCF10A cells engineered to express various mutated HER2 genes revealed that TAS0728 potently inhibited the phosphorylation of mutated HER2 and wild-type HER2. Furthermore, TAS0728 exhibited robust and sustained inhibition of the phosphorylation of HER2, HER3, and downstream effectors, thereby inducing apoptosis of HER2-amplified breast cancer cells and in tumor tissues of a xenograft model. TAS0728 induced tumor regression in mouse xenograft models bearing HER2 signal-dependent tumors and exhibited a survival benefit without any evident toxicity in a peritoneal dissemination mouse model bearing HER2-driven cancer cells. Taken together, our results demonstrated that TAS0728 may offer a promising therapeutic option with improved efficacy as compared with current HER2 inhibitors for HER2-activated cancers. Assessment of TAS0728 in ongoing clinical trials is awaited (NCT03410927).

Identification of RFC5 as a novel potential prognostic biomarker in lung cancer through bioinformatics analysis

Lung cancer is the leading cause of mortalities among all types of cancer. Therefore, the screening of biomarkers that are related with the progression of lung cancer is crucial for early diagnosis and efficient therapy of lung cancer. In the present study, bioinformatic analysis identified replication factor C 5 (RFC5) as a potential novel oncogene in lung cancer. RFC5 functions as a clamp loader and is involved in DNA replication and repair. Analysis of public databases and reverse transcription-quantitative polymerase chain reaction indicated that RFC5 was significantly increased in tumor tissues compared with adjacent normal tissues. A high RFC5 expression was observed to be associated with more aggressive malignant clinicopathological features, including higher T stage, more advanced regional lymph node metastasis and a higher probability of relapse. Notably, there were notable differences in overall survival (OS), first progression and post-progression survival between the high RFC5 expression group and low RFC5 expression group. Univariate and multivariate Cox regression analyses indicated that RFC5 was an independent risk factor that was associated with poorer OS and disease-free survival. According to GSEA, several gene sets that are associated with cell cycle and DNA damage were enriched in the RFC5 overexpression group, which indicated that RFC5 might promote the proliferation of lung cancer cells. Our finding indicated that RFC5 might be a novel prognostic biomarker of lung cancer, and it might be serve as a potential diagnosis and therapy target for lung cancer in the future.

Optimization Of Cancer Treatment Through Overcoming Drug Resistance

Cancer Drug resistance is a medical concern that requires extensive research and a thorough understanding in order to overcome. Remarkable achievements related to this field have been accomplished and further work is needed in order to optimize the cure for cancer and serve as the basis for precise medicine with few or no side effects.

EGFR tyrosine kinase inhibitor HS-10182 increases radiation sensitivity in non-small cell lung cancers with EGFR T790M mutation

Objective:

To investigate the potential of HS-10182, a second-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), as a radiosensitizer in non-small cell lung cancer (NSCLC).

Methods:

Two cell lines of NSCLCs, A549 that possesses wild-type (WT) EGFRs and H1975 that possesses EGFR L858R/T790M double mutations, were treated with HS-10182 at various concentrations, and cell viabilities were determined using the MTS assay. The cells were tested by clonogenic survival assays to identify the radiosensitivity of both groups. Western blot was performed to analyze the expression of phosphorylated EGFR, AKT, DNA-dependent protein kinase, and catalytic subunit (DNA-PKcs) proteins. Immunofluorescence analyses were performed to examine the formation and changes in nuclear γ-H2AX foci. Cell apoptosis was examined by flow cytometry and Western blots for cleaved caspase-3, -8, -9, and cleaved poly ADP-ribose polymerase (PARP). Furthermore, we established xenograft models in mice and the effects of different treatments on tumor growth were then assessed.

Results:

Clonogenic survival assays revealed that HS-10182 significantly enhanced the radiosensitivity of H1975 cells but not A549 cells [dose enhancement ratios (DERs)=2.36 (P < 0.05) vs. 1.43 (P > 0.05)]. Western blot results showed that HS-10182 increased the levels of cleaved caspase-3, -8, -9, and cleaved PARP in H1975 cells but not in A549 cells. In addition, flow cytometry analysis showed that HS-10182 enhanced irradiation-induced apoptosis in H1975. Immunofluorescence results found that HS-10182 increased the average number of γ-H2AX foci after irradiation in H1975 cells, but not in A549 cells. Combined radiation and HS-10182 treatment increased the expression of DNA-PKcs but this increase was more significant in H1975 cells than in A549 cells. Moreover, HS-10182 suppressed the increased expression of Rad50 in H1975 cells in response to irradiation. In vivo experiments found that the combined therapy significantly inhibited tumor growth.

Conclusions:

HS-10182 enhances the radiosensitivity of H1975 cells which is possibly because that HS-10182 could enhance irradiation-induced apoptosis, increase irradiation-induced DNA damage, and cause a delay in DNA damage repair. Our findings suggest that radiotherapy combined HS-10182 is a novel treatment for lung cancer cells which have acquired the T790M mutation. HS-10182 could be brought to the clinic as a radiosensitizer in NSCLCs with the EGFR T790M mutation.