Overcoming therapy resistance in EGFR-mutant lung cancer

The study of primary and acquired resistance to first-line osimertinib to improve the outcome of EGFR-mutated advanced Non-small cell lung cancer patients: the challenge is open for new therapeutic strategies

The development of targeted therapy in epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) patients has radically changed their clinical perspectives. Current first-line standard treatment for advanced disease is commonly considered third-generation tyrosine kinase inhibitors (TKI), osimertinib. The study of primary and acquired resistance to front-line osimertinib is one of the main burning issues to further improve patients' outcome. Great heterogeneity has been depicted in terms of duration of clinical benefit and pattern of progression and this might be related to molecular factors including subtypes of EGFR mutations and concomitant genetic alterations. Acquired resistance can be categorized into two main classes: EGFR-dependent and EGFR-independent mechanisms and specific pattern of progression to first-line osimertinib have been demonstrated. The purpose of the manuscript is to provide a comprehensive overview of literature about molecular resistance mechanisms to first-line osimertinib, from a clinical perspective and therefore in relationship to emerging therapeutic approaches.

Tenovin 3 induces apoptosis and ferroptosis in EGFR 19del non small cell lung cancer cells

Epidermal growth factor receptor (EGFR) exon 19 deletion is a major driver for the drug resistance of non-small cell lung cancer (NSCLC). Identification small inhibitor capable of selectively inhibiting EGFR-19del NSCLC is a desirable strategy to overcome drug resistance in NSCLC. This study aims to screen an inhibitor for EGFR exon 19 deletion cells and explore its underlying mechanism. High through-put screen was conducted to identify an inhibitor for EGFR-19del NSCLC cells. And tenovin-3 was identified as a selective inhibitor of PC9 cells, an EGFR-19del NSCLC cells. Tenovin-3 showed particular inhibition effect on PC9 cells proliferation through inducing apoptosis and ferroptosis. Mechanistically, tenovin-3 might induce the apoptosis and ferroptosis of PC9 cells through mitochondrial pathway, as indicated by the change of VDAC1 and cytochrome c (cyt c). And bioinformatics analyses showed that the expression levels of SLC7A11 and CPX4 were correlated with NSCLC patient's survival. Our findings provide evidences for tenovin-3 to be developed into a novel candidate agent for NSCLC with EGFR exon 19 deletion. Our study also suggests that inducing ferroptosis may be a therapeutic strategy for NSCLC with EGFR exon 19 deletion.

Targeting solid tumor antigens with chimeric receptors: cancer biology meets synthetic immunology

Chimeric antigen receptor (CAR) T cell therapy is a medical breakthrough in the treatment of B cell malignancies. There is intensive focus on developing solid tumor-targeted CAR-T cell therapies. Although clinically approved CAR-T cell therapies target B cell lineage antigens, solid tumor targets include neoantigens and tumor-associated antigens (TAAs) with diverse roles in tumor biology. Multiple early-stage clinical trials now report encouraging signs of efficacy for CAR-T cell therapies that target solid tumors. We review the landscape of solid tumor target antigens from the perspective of cancer biology and gene regulation, together with emerging clinical data for CAR-T cells targeting these antigens. We then discuss emerging synthetic biology strategies and their application in the clinical development of novel cellular immunotherapies.

Germline USP36 Mutation Confers Resistance to EGFR-TKIs by Upregulating MLLT3 Expression in Patients with Non-Small Cell Lung Cancer

PURPOSE

Although somatic mutations were explored in depth, limited biomarkers were found to predict the resistance of EGFR tyrosine kinase inhibitors (EGFR-TKI). Previous studies reported N6-methyladenosine (m6A) levels regulated response of EGFR-TKIs; whether the germline variants located in m6A sites affected resistance of EGFR-TKIs is still unknown.

EXPERIMENTAL DESIGN

Patients with non-small cell lung cancer (NSCLC) with EGFR-activating mutation were enrolled to investigate predictors for response of EGFR-TKIs using a genome-wide-variant-m6A analysis. Bioinformatics analysis and series of molecular biology assays were used to uncover the underlying mechanism.

RESULTS

We identified the germline mutation USP36 rs3744797 (C > A, K814N) was associated with survival of patients with NSCLC treated with gefitinib [median progression-free survival (PFS): CC vs. CA, 16.30 vs. 10.50 months, P < 0.0001, HR = 2.45] and erlotinib (median PFS: CC vs. CA, 14.13 vs. 9.47 months, P = 0.041, HR = 2.63). Functionally, the C > A change significantly upregulated USP36 expression by reducing its m6A level. Meanwhile, rs3744797_A (USP36 MUT) was found to facilitate proliferation, migration, and resistance to EGFR-TKIs via upregulating MLLT3 expression in vitro and in vivo. More importantly, MLLT3 and USP36 levels are tightly correlated in patients with NSCLC, which were associated with prognosis of patients. Mechanistically, USP36 MUT stabilized MLLT3 by deubiquitinating MLLT3 in nucleoli and consequently activating its downstream signaling (HIF1α and Snai). Furthermore, inhibition of MLLT3 alleviated USP36 variant-induced EGFR-TKIs resistance in EGFR-mutant NSCLC.

CONCLUSIONS

These findings characterized rs3744797 as an oncogenic variant in mediating EGFR-TKI resistance and tumor aggressiveness through deubiquitinating MLLT3, highlighting the variant as a predictive biomarker for EGFR-TKI response in NSCLC.

NEAT1_1 confers gefitinib resistance in lung adenocarcinoma through promoting AKR1C1-mediated ferroptosis defence

Gefitinib is one of the most extensively utilized epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) for treating advanced lung adenocarcinoma (LUAD) patients harboring EGFR mutation. However, the emergence of drug resistance significantly compromised the clinical efficacy of EGFR-TKIs. Gaining further insights into the molecular mechanisms underlying gefitinib resistance holds promise for developing novel strategies to overcome the resistance and improve the prognosis in LUAD patients. Here, we identified that the inhibitory efficacy of gefitinib on EGFR-mutated LUAD cells was partially dependent on the induction of ferroptosis, and ferroptosis protection resulted in gefitinib resistance. Among the ferroptosis suppressors, aldo-keto reductase family 1 member C1 (AKR1C1) exhibited significant upregulation in gefitinib-resistant strains of LUAD cells and predicted poor progression-free survival (PFS) and overall survival (OS) of LUAD patients who received first-generation EGFR-TKI treatment. Knockdown of AKR1C1 partially reversed drug resistance by re-sensitizing the LUAD cells to gefitinib-mediated ferroptosis. The decreased expression of miR-338-3p contributed to the aberrant upregulation of AKR1C1 in gefitinib-resistant LUAD cells. Furthermore, upregulated long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1_1 (NEAT1_1) sponged miR-338-3p to neutralize its suppression on AKR1C1. Dual-luciferase reporter assay and miRNA rescue experiment confirmed the NEAT1_1/miR-338-3p/AKR1C1 axis in EGFR-mutated LUAD cells. Gain- and loss-of-function assays demonstrated that the NEAT1_1/miR-338-3p/AKR1C1 axis promoted gefitinib resistance, proliferation, migration, and invasion in LUAD cells. This study reveals the effects of NEAT1_1/miR-338-3p/AKR1C1 axis-mediated ferroptosis defence in gefitinib resistance in LUAD. Thus, targeting NEAT1_1/miR-338-3p/AKR1C1 axis might be a novel strategy for overcoming gefitinib resistance in LUAD harboring EGFR mutation.

Adeno-to-squamous transition drives resistance to KRAS inhibition in LKB1 mutant lung cancer

KRASG12C inhibitors (adagrasib and sotorasib) have shown clinical promise in targeting KRASG12C-mutated lung cancers; however, most patients eventually develop resistance. In lung patients with adenocarcinoma with KRASG12C and STK11/LKB1 co-mutations, we find an enrichment of the squamous cell carcinoma gene signature in pre-treatment biopsies correlates with a poor response to adagrasib. Studies of Lkb1-deficient KRASG12C and KrasG12D lung cancer mouse models and organoids treated with KRAS inhibitors reveal tumors invoke a lineage plasticity program, adeno-to-squamous transition (AST), that enables resistance to KRAS inhibition. Transcriptomic and epigenomic analyses reveal ΔNp63 drives AST and modulates response to KRAS inhibition. We identify an intermediate high-plastic cell state marked by expression of an AST plasticity signature and Krt6a. Notably, expression of the AST plasticity signature and KRT6A at baseline correlates with poor adagrasib responses. These data indicate the role of AST in KRAS inhibitor resistance and provide predictive biomarkers for KRAS-targeted therapies in lung cancer.

Molecular features and clinical outcomes of EGFR-mutated, MET-amplified non-small-cell lung cancer after resistance to dual-targeted therapy

Background

Some studies of dual-targeted therapy (DTT) targeting epidermal growth factor receptor (EGFR) and mesenchymal-epithelial transition (MET) have shown promising efficacy in non-small-cell lung cancer (NSCLC). Consequently, patient management following DTT resistance has gained significance. However, the underlying resistance mechanisms and clinical outcomes in these patients remain unclear.

Objectives

This study aimed to delineate the molecular characteristics and survival outcomes of patients with NSCLC harboring EGFR mutations and acquired MET amplification after developing resistance to DTT.

Design

We conducted a retrospective analysis of patients with NSCLC with EGFR mutations and acquired MET amplification who exhibited resistance to EGFR/MET DTT.

Methods

Next-generation sequencing (NGS) was performed on patients with available tissue samples before and/or after the development of resistance to DTT. Stratified analyses were carried out based on data sources and subsequent salvage treatments. Univariate/multivariate Cox regression models and survival analyses were employed to explore potential independent prognostic factors.

Results

The study included 77 NSCLC patients, with NGS conducted on 19 patients. We observed many resistance mechanisms, including EGFR-dependent pathways (4/19, 21.1%), MET-dependent pathways (2/19, 10.5%), EGFR/MET co-dependent pathways (2/19, 10.5%), and EGFR/MET-independent resistance mechanisms (11/19, 57.9%). Post-progression progression-free survival (pPFS) and post-progression overall survival (pOS) significantly varied among patients who received the best supportive care (BSC), targeted therapy, or chemotherapy (CT), with median pPFS of 1.5, 3.9, and 4.9 months, respectively (p = 0.003). Median pOS were 2.3, 7.7, and 9.2 months, respectively (p < 0.001). The number of treatment lines following DTT resistance and the Eastern Cooperative Oncology Group performance status emerged as the independent prognostic factors.

Conclusion

This study revealed a heterogeneous landscape of resistance mechanisms to EGFR/MET DTT, with a similar prevalence of on- and off-target mechanisms. Targeted therapy or CT, as compared to BSC, exhibited the potential to improve survival outcomes for patients with advanced NSCLC following resistance to DTT.

Identification of ATAD3A as a key regulator in non-small cell lung cancer by promoting STAT3-induced cell proliferation and tumor angiogenesis

Malignant proliferation and abundant angiogenesis are major causes of lung adenocarcinoma (LUAD) with high morbidity and mortality. Therefore, the exploration of the key regulatory mechanisms of malignant proliferation and angiogenesis in LUAD provides an opportunity for the development of targeted precision therapy. In this study, we found that the high expression of ATPase family AAA domain-containing protein 3A (ATAD3A) in LUAD was positively associated with the poor survival of patients, while its high expression was positively associated with the angiogenesis of LUAD. Further knockdown of ATAD3A in LUAD significantly inhibited cell proliferation and suppressed expression of vascular endothelial growth factor A, FGF-2, ANG-1, and TGF-β. The opposite effect was observed with ATAD3A overexpression. Furthermore, ATAD3A knockdown significantly inhibited tumor growth and angiogenesis in an in vivo subcutaneous xenograft tumor model. Mechanistic studies suggest that ATAD3A may promote signal transducer and activator of transcription 3 activation, a key signal regulating lung cancer cell proliferation and transcriptional secretion of proangiogenic factors. Therefore, targeted inhibition of ATAD3A may be an effective strategy for LUAD therapy, and ATAD3A may be a potential biomarker for predicting malignant progression.

MUC1-C Is a Common Driver of Acquired Osimertinib Resistance in NSCLC

INTRODUCTION

Osimertinib is an irreversible EGFR tyrosine kinase inhibitor approved for the first-line treatment of patients with metastatic NSCLC harboring EGFR exon 19 deletions or L858R mutations. Patients treated with osimertinib invariably develop acquired resistance by mechanisms involving additional EGFR mutations, MET amplification, and other pathways. There is no known involvement of the oncogenic MUC1-C protein in acquired osimertinib resistance.

METHODS

H1975/EGFR (L858R/T790M) and patient-derived NSCLC cells with acquired osimertinib resistance were investigated for MUC1-C dependence in studies of EGFR pathway activation, clonogenicity, and self-renewal capacity.

RESULTS

We reveal that MUC1-C is up-regulated in H1975 osimertinib drug-tolerant persister cells and is necessary for activation of the EGFR pathway. H1975 cells selected for stable osimertinib resistance (H1975-OR) and MGH700-2D cells isolated from a patient with acquired osimertinib resistance are found to be dependent on MUC1-C for induction of (1) phospho (p)-EGFR, p-ERK, and p-AKT, (2) EMT, and (3) the resistant phenotype. We report that MUC1-C is also required for p-EGFR, p-ERK, and p-AKT activation and self-renewal capacity in acquired osimertinib-resistant (1) MET-amplified MGH170-1D #2 cells and (2) MGH121 Res#2/EGFR (T790M/C797S) cells. Importantly, targeting MUC1-C in these diverse models reverses osimertinib resistance. In support of these results, high MUC1 mRNA and MUC1-C protein expression is associated with a poor prognosis for patients with EGFR-mutant NSCLCs.

CONCLUSIONS

Our findings reveal that MUC1-C is a common effector of osimertinib resistance and is a potential target for the treatment of osimertinib-resistant NSCLCs.

Small cell lung cancer transformations from non-small cell lung cancer: Biological mechanism and clinical relevance

Lung cancer is a leading cause of cancer deaths worldwide, consisting of two major histological subtypes: small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC). In some cases, NSCLC patients may undergo a histological transformation to SCLC during clinical treatments, which is associated with resistance to targeted therapy, immunotherapy, or chemotherapy. The review provides a comprehensive analysis of SCLC transformation from NSCLC, including biological mechanism, clinical relevance, and potential treatment options after transformation, which may give a better understanding of SCLC transformation and provide support for further research to define better therapy options.

Factors associated with prolonged progression-free survival of patients treated with first-line afatinib for advanced epidermal growth factor receptor-mutated non-small cell lung cancer

BACKGROUND

This study aimed to investigate the factors associated with prolonged progression-free survival (PFS) (>36 months) of advanced non-small cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) mutations treated with first-line afatinib.

METHODS

We performed a retrospective analysis of data of patients with advanced EGFR-mutated NSCLC receiving first-line afatinib at two tertiary care referral centers, Linkou and Kaohsiung Chang Gung Memorial Hospital, in Taiwan between June 2014 and April 2022.

RESULTS

The data of 546 treatment-naïve EGFR-mutated advanced NSCLC patients were analyzed. Median PFS and overall survival were 14.5 months and 27.2 months, respectively. The PFS of 462 patients (84.6%) was less than 36 months and of 84 patients (15.4%) was more than 36 months. The PFS > 36 months group had a significantly higher percentage of patients with uncommon mutations (p = 0.002). The PFS ≤36 months group had significantly higher incidences of bone, liver, and adrenal metastases (all p < 0.05) and a higher rate of multiple distant metastases. Multivariate logistic regression analysis showed that liver metastasis was negatively and independently associated with prolonged PFS (adjusted odds ratio = 0.246 [95% CI: 0.067-0.908], p = 0.035). The median overall survival of the PFS >36 months group was 46.0 months and that of the PFS ≤36 months group was 22.9 months (log-rank test, p < 0.001).

CONCLUSIONS

We found that EGFR-mutated NSCLC patients receiving first-line afatinib were prone to shorter PFS if they had distant organ metastasis, especially liver metastasis.

Detecting EGFR gene amplification using a fluorescence in situ hybridization platform based on digital microfluidics

Signal transduction mediated by epidermal growth factor receptor (EGFR) gene affects the proliferation, invasion, metastasis, and angiogenesis of tumor cells. In particular, non-small cell lung cancer (NSCLC) patients with increased in copy number of EGFR gene are often sensitive to tyrosine kinase inhibitors. Despite being the standard for detecting EGFR amplification in the clinic, fluorescence in situ hybridization (FISH) traditionally involves repetitive and complex benchtop procedures that are not only time consuming but also require well-trained personnel. To address these limitations, we develop a digital microfluidics-based FISH platform (DMF-FISH) that automatically implements FISH operations. This system mainly consists of a DMF chip for reagent operation, a heating array for temperature control and a signal processing system. With the capability of automatic droplet handling and efficient temperature control, DMF-FISH performs cell digestion, gradient elution, hybridization and DAPI staining without manual intervention. In addition to operational feasibility, DMF-FISH yields comparable performance with the benchtop FISH protocol but reducing the consumption of DNA probe by 87 % when tested with cell lines and clinical samples. These results highlight unique advantages of the fully automated DMF-FISH system and thus suggest its great potential for clinical diagnosis and personalized therapy of NSCLC.

Clinical characteristics of patients treated with immune checkpoint inhibitors in EGFR-mutant non-small cell lung cancer: CS-Lung-003 prospective observational registry study

PURPOSE

Immune checkpoint inhibitors (ICIs) are ineffective against epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC). This study aimed to investigate the clinical characteristics of patients who were treated or not treated with ICIs, and of those who benefit from immunotherapy in EGFR-mutant NSCLC.

METHODS

We analyzed patients with unresectable stage III/IV or recurrent NSCLC harboring EGFR mutations using a prospective umbrella-type lung cancer registry (CS-Lung-003).

RESULTS

A total of 303 patients who met the eligibility criteria were analyzed. The median age was 69 years; 116 patients were male, 289 had adenocarcinoma, 273 had major mutations, and 67 were treated with ICIs. The duration of EGFR-TKI treatment was longer in the Non-ICI group than in the ICI group (17.1 vs. 12.7 months, p < 0.001). Patients who received ICIs for more than 6 months were categorized into the durable clinical benefit (DCB) group (24 patients), and those who received ICIs for less than 6 months into the Non-DCB group (43 patients). The overall survival in the DCB group exhibited longer than the Non-DCB group (69.3 vs. 47.1 months), and an equivalent compared to that in the Non-ICI group (69.3 vs. 68.9 months). Multivariate analysis for time to next treatment (TTNT) of ICIs showed that a poor PS was associated with a shorter TTNT [hazard ratio (HR) 3.309; p < 0.001]. Patients who were treated with ICIs and chemotherapy combination were associated with a longer TTNT (HR 0.389; p = 0.003). In addition, minor EGFR mutation was associated with a long TTNT (HR 0.450; p = 0.046).

CONCLUSION

ICIs were administered to only 22% of patients with EGFR-mutated lung cancer, and they had shorter TTNT of EGFR-TKI compared to other patients. ICI treatment should be avoided in EGFR mutated lung cancer with poor PS but can be considered for lung cancer with EGFR minor mutations. Pathological biomarker to predict long-term responders to ICI are needed.

Plasma ddPCR for the detection of MET amplification in advanced NSCLC patients: a comparative real-world study

Background

Mesenchymal-epithelial transition (MET) amplification is a crucial oncogenic driver and a resistance mechanism to epidermal growth factor receptor tyrosine kinase inhibitors (TKIs) of non-small-cell lung cancer (NSCLC). Fluorescence in situ hybridization (FISH) is the gold standard for MET amplification detection. However, it is inapplicable when tissue samples are unavailable.

Objective

This study assessed the performance of plasma droplet digital polymerase chain reaction (ddPCR) in MET amplification detection in NSCLC patients.

Design and methods

A total of 87 NSCLC patients were enrolled, and 94 paired tissue and plasma samples were analyzed for the concordance between FISH and plasma ddPCR/tissue next-generation sequencing (NGS) in detecting MET amplification. In addition, the efficacy of patients with MET amplification using different detection methods who were treated with MET-TKIs was evaluated.

Results

Plasma ddPCR showed substantial concordance with FISH (74.1% sensitivity, 92.5% specificity, and 87.2% accuracy with a kappa value of 0.68) and outperformed tissue NGS (kappa value of 0.64) in MET amplification detection. Combined plasma ddPCR and tissue NGS showed substantial concordance with FISH (92.3% sensitivity, 89.2% specificity, and an accuracy of 90.1% with a kappa value of 0.77). The efficacy is comparable in these NSCLC patients with MET amplification detected by FISH and plasma ddPCR who were treated with MET-TKIs.

Conclusion

Plasma ddPCR is a potentially reliable method for detecting MET amplification in advanced NSCLC patients. Combined plasma ddPCR and tissue NGS might be an alternative or complementary method to MET amplification detection.

RELAY, Erlotinib Plus Ramucirumab in Untreated, EGFR-Mutated, Metastatic NSCLC: Outcomes by EGFR Exon 19 Deletion Variants

Introduction

EGFR gene mutations are drivers of NSCLC. The RELAY double-blind, placebo (PBO)-controlled phase 3 study revealed superior progression-free survival (PFS) for ramucirumab plus erlotinib (RAM + ERL) versus PBO (PBO + ERL) in patients with untreated advanced NSCLC and an EGFR-activating mutation. This exploratory analysis evaluated potential associations between EGFR exon 19 deletion (ex19del) variants and clinical outcomes.

Methods

Patients (N = 449) were randomized (1:1) to RAM plus ERL or PBO plus ERL. Plasma samples were collected at baseline, on treatment, and at 30-day post-study treatment discontinuation follow-up. Baseline and treatment-emergent gene alterations were investigated by Guardant360 next-generation sequencing. Patients with a valid baseline plasma sample and ex19del were included (RAM + ERL, n = 62; PBO + ERL, n = 72).

Results

The most common ex19del variant was E746_A750del (67.2%); EGFR E746 deletions (E746del) occurred more frequently than L747 deletions (74.6% versus 25.4%, respectively). TP53 mutations were the most frequently co-occurring baseline gene alterations. With treatment arms combined, median PFS was 18.0 months versus 12.5 months for patients with uncommon (non-E746_A750del, n = 44) versus common (E746_A750del, n = 90) ex19del variants (hazard ratio [HR] = 1.657 [95% confidence interval or CI:1.044-2.630]). Median PFS was longer with RAM plus ERL versus PBO plus ERL for patients with the common (15.2 versus 9.9 mo; HR = 0.564 [95% CI: 0.344-0.926]) and E746del (15.4 versus 9.9 mo; HR = 0.587 [95% CI: 0.363-0.951]) variants. Treatment-emergent post-progression EGFR T790M rates were higher in the common versus uncommon and E746del versus L747 deletion subgroups.

Conclusions

RAM plus ERL provides benefit and improves treatment outcomes for patients with metastatic NSCLC with EGFR ex19del variants.

Design, synthesis and biological evaluation of potent epidermal growth factor receptor tyrosine kinase (EGFR-TK) inhibitors against resistance mutation for lung cancer treatment

In this study, we identified a newly synthesized compound 7o with potent inhibition on EGFR primary mutants (L858R, Del19) and drug-resistant mutant T790M with nanomolar IC50 values. 7o showed strong antiproliferative effects against EGFR mutant-driven non-small cell lung cancer (NSCLC) cells such as H1975, PC-9 and HCC827, over cells expressing EGFRWT. Molecular docking was performed to investigate the possible binding modes of 7o inside the binding site of EGFRL858R/T790M and EGFRWT. Analysis of cell cycle evidenced that 7o induced cell cycle arrest in G1 phases in the EGFR mutant cells, H1975 and PC-9, which resulted in decreased S-phase populations. Moreover, compound 7o induced cancer cell apoptosis in in vitro assays. In addition, 7o inhibited cellular phosphorylation of EGFR. In vivo, oral administration of 7o caused rapid tumor regression in H1975 xenograft model. Therefore, 7o might deserve further optimization as cancer treatment agent for EGFR mutant-driven NSCLC.

Valproic acid increased the efficacy of EGFR TKIs on EGFR/TP53 co-mutated lung cancers and downregulated mutant-p53 levels

The TP53 tumor suppressor is the most frequently mutated gene in human cancers. For p53-targeted therapy, one of the strategies was targeting mutant p53 for degradation. In EGFR-mutated lung cancer patients, concurrent TP53 mutation was associated with faster resistance to EGFR-TKIs. In this study, we discovered that valproic acid (VPA), a widely prescribed antiseizure medication, had a synergic effect on sensitive as well as acquired resistant lung cancers with EGFR/TP53 co-mutation in combination with EGFR-TKIs. In both in vitro and in vivo models, VPA greatly improved the efficacy of EGFR-TKIs, including forestalling the occurrence of acquired resistance and increasing the sensitivity to EGFR-TKIs. Mechanistically, VPA dramatically promoted degradation of mutant p53 in both sensitive and acquired resistant cells while inhibited mutant TP53 mRNA transcription only in sensitive cells. Together, this study suggested that VPA combination treatment could have beneficial effects on EGFR-mutant lung cancers with concurrent p53 mutation in both early and late stages, expanding the potential clinical applications for VPA.

Covalent inhibition of epidermal growth factor receptor using a long-lived iridium(III)-afatinib probe

The overexpression and overactivation of epidermal growth factor receptor (EGFR) are frequently observed in human cancers, including squamous cell carcinoma and adenocarcinoma. In this study, a covalent EGFR probe was developed by conjugating afatinib to an iridium(III) scaffold. Complex 1 showed enhanced luminescence in living epidermoid squamous carcinoma A431 cells compared to other cell lines, via engaging EGFR as confirmed via CETSA and knockdown experiments. Moreover, complex 1 inhibited downstream targets of EGFR in cellulo with repression persisting after removal of the complex, indicating an irreversible mode of inhibition. Finally, complex 1 showed potent antiproliferative activity against A431 cells with comparable potency to afatinib alone. To our knowledge, complex 1 is the first EGFR covalent inhibitor based on an iridium scaffold reported in the literature, with the potential to be further explored as a theranostic agent in the future.

Vaccine antibodies against a synthetic epidermal growth factor variant enhance the antitumor effects of inhibitors targeting the MAPK/ERK and PI3K/Akt pathways

BACKGROUND

The EGFR pathway is involved in intrinsic and acquired resistance to a wide variety of targeted therapies in cancer. Vaccination represents an alternative to the administration of anti-EGFR monoclonal antibodies, such as cetuximab or panitumumab. Here, we tested if anti-EGF antibodies generated by vaccination (anti-EGF VacAbs) could potentiate the activity of drugs targeting the ERK/MAPK and PI3K/Akt pathways.

METHODS

Non-small cell lung cancer (NSCLC), colorectal cancer (CRC) and melanoma cell lines harboring KRAS, NRAS, BRAF and PIK3CA mutations were used. Anti-EGF VacAbs were obtained by immunizing rabbits with a fusion protein containing a synthetic, highly mutated variant of human EGF. Cell viability was determined by MTT, total and phosphorylated proteins by Western blotting, cell cycle distribution and cell death by flow cytometry and emergence of resistance by microscopic examination in low density cultures.

RESULTS

Anti-EGF VacAbs potentiated the antiproliferative effects of MEK, KRAS G12C, BRAF, PI3K and Akt inhibitors in KRAS, NRAS, BRAF and PIK3CA mutant cells and delayed the appearance of resistant clones in vitro. The effects of anti-EGF VacAbs were comparable or superior to those of panitumumab and cetuximab. The combination of anti-EGF VacAbs with the targeted inhibitors effectively suppressed EGFR downstream pathways and sera from patients immunized with an anti-EGF vaccine also blocked activation of EGFR effectors.

CONCLUSIONS

Anti-EGF VacAbs enhance the antiproliferative effects of drugs targeting the ERK/MAPK and PIK3CA/Akt pathways. Our data provide a rationale for clinical trials testing anti-EGF vaccination combined with inhibitors selected according to the patient's genetic profile.

QL1706 (anti-PD-1 IgG4/CTLA-4 antibody) plus chemotherapy with or without bevacizumab in advanced non-small cell lung cancer: a multi-cohort, phase II study

First-line chemoimmunotherapy (with or without bevacizumab) has improved outcomes in advanced non-small cell lung cancer (NSCLC). Here, this open-label, multi-cohort phase II study (NCT05329025) was done to investigate the safety and efficacy of QL1706 (a single bifunctional MabPair product against PD-1 and CTLA-4) and chemotherapy with or without bevacizumab in this population. Patients were enrolled into five different cohorts based on genotype (cohorts 1-4, epidermal growth factor receptor [EGFR] wild-type; cohort 5, EGFR-mutant and progressed on EGFR-tyrosine kinase inhibitors [TKIs]). Between June 11, 2021 and December 29, 2021, 91 patients were enrolled. Most frequent treatment-related adverse events (TRAEs) included decreased appetite (60 [65.9%]), anemia (60 [65.9%]), infusion-related reactions (48 [52.7%]), and pruritus (44 [48.4%]). Grade ≥ 3 TRAEs occurred in 30 (33.0%) patients. Twenty-seven (45%) patients with wild-type EGFR achieved partial response (PR) (objective response rate [ORR] = 45%) and had a median progression-free survival (mPFS) of 6.8 months (95% CI: 5.2-9.7). For 31 patients harboring mutated EGFR, 17 (54.8%) achieved PR (ORR = 54.8%), with an mPFS of 8.5 months (95% CI: 5.72-not evaluable). Overall, QL1706 plus chemotherapy, regardless of having bevacizumab, was generally tolerable and had promising antitumor activity for EGFR wild-type advanced NSCLC in first-line setting. Moreover, QL1706 plus chemotherapy and bevacizumab showed favorable antitumor activity for patients who had EGFR mutated NSCLC but failed in TKI therapy, demonstrating a potential for treating this population.

4″-Alkyl EGCG Derivatives Induce Cytoprotective Autophagy Response by Inhibiting EGFR in Glioblastoma Cells

Epidermal growth factor receptor (EGFR)-targeted therapy has been proven vital in the last two decades for the treatment of multiple cancer types, including nonsmall cell lung cancer, glioblastoma, breast cancer and head and neck squamous cell carcinoma. Unfortunately, the majority of approved EGFR inhibitors fall into the drug resistance category because of continuous mutations and acquired resistance. Recently, autophagy has surfaced as one of the emerging underlying mechanisms behind resistance to EGFR-tyrosine kinase inhibitors (TKIs). Previously, we developed a series of 4″-alkyl EGCG (4″-Cn EGCG, n = 6, 8, 10, 12, 14, 16, and 18) derivatives with enhanced anticancer effects and stability. Therefore, the current study hypothesized that 4″-alkyl EGCG might induce cytoprotective autophagy upon EGFR inhibition, and inhibition of autophagy may lead to improved cytotoxicity. In this study, we have observed growth inhibition and caspase-3-dependent apoptosis in 4″-alkyl EGCG derivative-treated glioblastoma cells (U87-MG). We also confirmed that 4″-alkyl EGCG could inhibit EGFR in the cells, as well as mutant L858R/T790M EGFR, through an in vitro kinase assay. Furthermore, we have found that EGFR inhibition with 4″-alkyl EGCG induces cytoprotective autophagic responses, accompanied by the blockage of the AKT/mTOR signaling pathway. In addition, cytotoxicity caused by 4″-C10 EGCG, 4″-C12 EGCG, and 4″-C14 EGCG was significantly increased after the inhibition of autophagy by the pharmacological inhibitor chloroquine. These findings enhance our understanding of the autophagic response toward EGFR inhibitors in glioblastoma cells and suggest a potent combinatorial strategy to increase the therapeutic effectiveness of EGFR-TKIs.

Targeting HER3 to overcome EGFR TKI resistance in NSCLC

Receptor tyrosine kinases (RTKs) play a crucial role in cellular signaling and oncogenic progression. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) have become the standard treatment for advanced non-small cell lung cancer (NSCLC) patients with EGFR-sensitizing mutations, but resistance frequently emerges between 10 to 14 months. A significant factor in this resistance is the role of human EGFR 3 (HER3), an EGFR family member. Despite its significance, effective targeting of HER3 is still developing. This review aims to bridge this gap by deeply examining HER3's pivotal contribution to EGFR TKI resistance and spotlighting emerging HER3-centered therapeutic avenues, including monoclonal antibodies (mAbs), TKIs, and antibody-drug conjugates (ADCs). Preliminary results indicate combining HER3-specific treatments with EGFR TKIs enhances antitumor effects, leading to an increased objective response rate (ORR) and prolonged overall survival (OS) in resistant cases. Embracing HER3-targeting therapies represents a transformative approach against EGFR TKI resistance and emphasizes the importance of further research to optimize patient stratification and understand resistance mechanisms.

Preclinical Modeling of Pathway-Targeted Therapy of Human Lung Cancer in the Mouse

Animal models, particularly genetically engineered mouse models (GEMMs), continue to have a transformative impact on our understanding of the initiation and progression of hematological malignancies and solid tumors. Furthermore, GEMMs have been employed in the design and optimization of potent anticancer therapies. Increasingly, drug responses are assessed in mouse models either prior, or in parallel, to the implementation of precision medical oncology, in which groups of patients with genetically stratified cancers are treated with drugs that target the relevant oncoprotein such that mechanisms of drug sensitivity or resistance may be identified. Subsequently, this has led to the design and preclinical testing of combination therapies designed to forestall the onset of drug resistance. Indeed, mouse models of human lung cancer represent a paradigm for how a wide variety of GEMMs, driven by a variety of oncogenic drivers, have been generated to study initiation, progression, and maintenance of this disease as well as response to drugs. These studies have now expanded beyond targeted therapy to include immunotherapy. We highlight key aspects of the relationship between mouse models and the evolution of therapeutic approaches, including oncogene-targeted therapies, immunotherapies, acquired drug resistance, and ways in which successful antitumor strategies improve on efficiently translating preclinical approaches into successful antitumor strategies in patients.

Concurrent Tissue and Circulating Tumor DNA Molecular Profiling to Detect Guideline-Based Targeted Mutations in a Multicancer Cohort

Importance

Tissue-based next-generation sequencing (NGS) of solid tumors is the criterion standard for identifying somatic mutations that can be treated with National Comprehensive Cancer Network guideline-recommended targeted therapies. Sequencing of circulating tumor DNA (ctDNA) can also identify tumor-derived mutations, and there is increasing clinical evidence supporting ctDNA testing as a diagnostic tool. The clinical value of concurrent tissue and ctDNA profiling has not been formally assessed in a large, multicancer cohort from heterogeneous clinical settings.

Objective

To evaluate whether patients concurrently tested with both tissue and ctDNA NGS testing have a higher rate of detection of guideline-based targeted mutations compared with tissue testing alone.

Design, Setting, and Participants

This cohort study comprised 3209 patients who underwent sequencing between May 2020, and December 2022, within the deidentified, Tempus multimodal database, consisting of linked molecular and clinical data. Included patients had stage IV disease (non-small cell lung cancer, breast cancer, prostate cancer, or colorectal cancer) with sufficient tissue and blood sample quantities for analysis.

Exposures

Received results from tissue and plasma ctDNA genomic profiling, with biopsies and blood draws occurring within 30 days of one another.

Main Outcomes and Measures

Detection rates of guideline-based variants found uniquely by ctDNA and tissue profiling.

Results

The cohort of 3209 patients (median age at diagnosis of stage IV disease, 65.3 years [2.5%-97.5% range, 43.3-83.3 years]) who underwent concurrent tissue and ctDNA testing included 1693 women (52.8%). Overall, 1448 patients (45.1%) had a guideline-based variant detected. Of these patients, 9.3% (135 of 1448) had variants uniquely detected by ctDNA profiling, and 24.2% (351 of 1448) had variants uniquely detected by solid-tissue testing. Although largely concordant with one another, differences in the identification of actionable variants by either assay varied according to cancer type, gene, variant, and ctDNA burden. Of 352 patients with breast cancer, 20.2% (71 of 352) with actionable variants had unique findings in ctDNA profiling results. Most of these unique, actionable variants (55.0% [55 of 100]) were found in ESR1, resulting in a 24.7% increase (23 of 93) in the identification of patients harboring an ESR1 mutation relative to tissue testing alone.

Conclusions and Relevance

This study suggests that unique actionable biomarkers are detected by both concurrent tissue and ctDNA testing, with higher ctDNA identification among patients with breast cancer. Integration of concurrent NGS testing into the routine management of advanced solid cancers may expand the delivery of molecularly guided therapy and improve patient outcomes.

The mechanistic role of NAT10 in cancer: Unraveling the enigmatic web of oncogenic signaling

N-acetyltransferase 10 (NAT10), a versatile enzyme, has gained considerable attention as a significant player in the complex realm of cancer biology. Its enigmatic role in tumorigenesis extends across a wide array of cellular processes, impacting cell growth, differentiation, survival, and genomic stability. Within the intricate network of oncogenic signaling, NAT10 emerges as a crucial agent in multiple cancer types, such as breast, lung, colorectal, and leukemia. This compelling research addresses the intricate complexity of the mechanistic role of NAT10 in cancer development. By elucidating its active participation in essential physiological processes, we investigate the regulatory role of NAT10 in cell cycle checkpoints, coordination of chromatin remodeling, and detailed modulation of the delicate balance between apoptosis and cell survival. Perturbations in NAT10 expression and function have been linked to oncogenesis, metastasis, and drug resistance in a variety of cancer types. Furthermore, the bewildering interactions between NAT10 and key oncogenic factors, such as p53 and c-Myc, are deciphered, providing profound insights into the molecular underpinnings of cancer pathogenesis. Equally intriguing, the paradoxical role of NAT10 as a potential tumor suppressor or oncogene is influenced by context-dependent factors and the cellular microenvironment. This study explores the fascinating interplay of genetic changes, epigenetic changes, and post-translational modifications that shape the dual character of NAT10, revealing the delicate balance between cancer initiation and suppression. Taken together, this overview delves deeply into the enigmatic role of NAT10 in cancer, elucidating its multifaceted roles and its complex interplay with oncogenic networks.

Detecting acquired V-Raf murine sarcoma viral oncogene homolog B1 V600E mutation associated with osimertinib resistance in epidermal growth factor receptor-mutant lung adenocarcinoma: A case report

Osimertinib has demonstrated efficacy as the first- and second-line treatment for advanced non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) gene mutations. However, EGFR-mutant NSCLC cells often acquire resistance to osimertinib. V-Raf murine sarcoma viral oncogene homolog B1 (BRAF) mutation (BRAF V600E) was detected in a re-biopsy (LC-SCRUM-TRY testing) of a patient with advanced lung adenocarcinoma who was resistant to osimertinib treatment. Currently, the patient is receiving dabrafenib/trametinib combination therapy and is under observation; a slight shrinking effect of cancer has been observed.

MYC expression and fatty acid oxidation in EGFR-TKI acquired resistance

This report expands on our previous research, highlighting a unique inverse correlation between MYC expression in tumor cells and immune cells during the development of EGFR-TKI resistance. It is observed that MYC expression and fatty acid oxidation (FAO) metabolism in tissue-resident memory (TRM) CD8 + T cells are significantly impaired. These findings offer new insights into the mechanisms of TKI resistance. Although the study is preliminary, it suggests caution when interpreting the effectiveness of MYC inhibitors in reversing TKI resistance, especially when immune factors are not considered.

Amivantamab plus chemotherapy with and without lazertinib in EGFR-mutant advanced NSCLC after disease progression on osimertinib: primary results from the phase III MARIPOSA-2 study

BACKGROUND

Amivantamab plus carboplatin-pemetrexed (chemotherapy) with and without lazertinib demonstrated antitumor activity in patients with refractory epidermal growth factor receptor (EGFR)-mutated advanced non-small-cell lung cancer (NSCLC) in phase I studies. These combinations were evaluated in a global phase III trial.

PATIENTS AND METHODS

A total of 657 patients with EGFR-mutated (exon 19 deletions or L858R) locally advanced or metastatic NSCLC after disease progression on osimertinib were randomized 2 : 2 : 1 to receive amivantamab-lazertinib-chemotherapy, chemotherapy, or amivantamab-chemotherapy. The dual primary endpoints were progression-free survival (PFS) of amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy versus chemotherapy. During the study, hematologic toxicities observed in the amivantamab-lazertinib-chemotherapy arm necessitated a regimen change to start lazertinib after carboplatin completion.

RESULTS

All baseline characteristics were well balanced across the three arms, including by history of brain metastases and prior brain radiation. PFS was significantly longer for amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy versus chemotherapy [hazard ratio (HR) for disease progression or death 0.48 and 0.44, respectively; P < 0.001 for both; median of 6.3 and 8.3 versus 4.2 months, respectively]. Consistent PFS results were seen by investigator assessment (HR for disease progression or death 0.41 and 0.38 for amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy, respectively; P < 0.001 for both; median of 8.2 and 8.3 versus 4.2 months, respectively). Objective response rate was significantly higher for amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy versus chemotherapy (64% and 63% versus 36%, respectively; P < 0.001 for both). Median intracranial PFS was 12.5 and 12.8 versus 8.3 months for amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy versus chemotherapy (HR for intracranial disease progression or death 0.55 and 0.58, respectively). Predominant adverse events (AEs) in the amivantamab-containing regimens were hematologic, EGFR-, and MET-related toxicities. Amivantamab-chemotherapy had lower rates of hematologic AEs than amivantamab-lazertinib-chemotherapy.

CONCLUSIONS

Amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy improved PFS and intracranial PFS versus chemotherapy in a population with limited options after disease progression on osimertinib. Longer follow-up is needed for the modified amivantamab-lazertinib-chemotherapy regimen.

Nanomedicine Combats Drug Resistance in Lung Cancer

Lung cancer is the second most prevalent cancer and the leading cause of cancer-related death worldwide. Surgery, chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy are currently available as treatment methods. However, drug resistance is a significant factor in the failure of lung cancer treatments. Novel therapeutics have been exploited to address complicated resistance mechanisms of lung cancer and the advancement of nanomedicine is extremely promising in terms of overcoming drug resistance. Nanomedicine equipped with multifunctional and tunable physiochemical properties in alignment with tumor genetic profiles can achieve precise, safe, and effective treatment while minimizing or eradicating drug resistance in cancer. Here, this work reviews the discovered resistance mechanisms for lung cancer chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy, and outlines novel strategies for the development of nanomedicine against drug resistance. This work focuses on engineering design, customized delivery, current challenges, and clinical translation of nanomedicine in the application of resistant lung cancer.

Splice-Switching Antisense Oligonucleotides Targeting Extra- and Intracellular Domains of Epidermal Growth Factor Receptor in Cancer Cells

Cancer is one of the leading causes of death globally. Epidermal growth factor receptor is one of the proteins involved in cancer cell proliferation, differentiation, and invasion. Antisense oligonucleotides are chemical nucleic acids that bind to target messenger ribonucleic acid and modulate its expression. Herein, we demonstrate the efficacy of splice-modulating antisense oligonucleotides to target specific exons in the extracellular (exon 3) and intracellular (exon 18, 21) domains of epidermal growth factor receptor. These antisense oligonucleotides were synthesized as 25mer 2'-O methyl phosphorothioate-modified ribonucleic acids that bind to complementary specific regions in respective exons. We found that PNAT524, PNAT525, PNAT576, and PNAT578 effectively skipped exon 3, exon 18, and exon 21 in glioblastoma, liver cancer, and breast cancer cell lines. PNAT578 treatment also skipped partial exon 19, complete exon 20, and partial exon 21 in addition to complete exon 21 skipping. We also found that a cocktail of PNAT576 and PNAT578 antisense oligonucleotides performed better than their individual counterparts. The migration potential of glioblastoma cancer cells was reduced to a greater extent after treatment with these antisense oligonucleotides. We firmly believe that using these splice-modulating antisense oligonucleotides in combination with existing EGFR-targeted therapies could improve therapeutic outcomes.

Epigallocatechin gallate circumvents drug-induced resistance in non-small-cell lung cancer by modulating glucose metabolism and AMPK/AKT/MAPK axis

Upon prolonged use of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in non-small-cell lung cancer (NSCLC), acquired drug resistance inevitably occurs. This study investigates the combined use of EGFR-TKIs (gefitinib or osimertinib) with epigallocatechin gallate (EGCG) to overcome acquired drug resistance in NSCLC models. The in vitro antiproliferative effects of EGFR-TKIs and EGCG combination in EGFR-mutant parental and resistant cell lines were evaluated. The in vivo efficacy of the combination was assessed in xenograft mouse models derived from EGFR-TKI-resistant NSCLC cells. We found that the combined use of EGFR-TKIs and EGCG significantly reversed the Warburg effect by suppressing glycolysis while boosting mitochondrial respiration, which was accompanied by increased cellular ROS and decreased lactate secretion. The combination effectively activated the AMPK pathway while inhibited both ERK/MAPK and AKT/mTOR pathways, leading to cell cycle arrest and apoptosis, particularly in drug-resistant NSCLC cells. The in vivo results obtained from mouse tumor xenograft model confirmed that EGCG effectively overcame osimertinib resistance. This study revealed that EGCG suppressed cancer bypass survival signaling and altered cancer metabolic profiles, which is a promising anticancer adjuvant of EGFR-TKIs to overcome acquired drug resistance in NSCLC.

Harnessing G-quadruplex ligands for lung cancer treatment: A comprehensive overview

Lung cancer (LC) remains a leading cause of mortality worldwide, and new therapeutic strategies are urgently needed. One such approach revolves around the utilization of four-stranded nucleic acid secondary structures, known as G-quadruplexes (G4), which are formed by G-rich sequences. Ligands that bind selectively to G4 structures present a promising strategy for regulating crucial cellular processes involved in the progression of LC, rendering them potent agents for lung cancer treatment. In this review, we offer a summary of recent advancements in the development of G4 ligands capable of targeting specific genes associated with the development and progression of lung cancer.

Cerebrospinal fluid circulating tumor DNA contributes to the detection and characterization of leptomeningeal metastasis in non-small cell lung cancer

PURPOSE

Cerebrospinal fluid (CSF) has revealed the unique genetic characteristics of leptomeningeal metastasis (LM) from non-small cell lung cancer (NSCLC). However, the research in this area is still very limited.

METHODS

Patients with LM from NSCLC (n = 80) were retrospectively analyzed. Circulating tumor DNA (ctDNA) in CSF was tested by next-generation sequencing (NGS), with paired extracranial tissue or plasma samples included for comparison. An independent non-LM cohort (n = 100) was also analyzed for comparative purposes. Clinical outcomes were compared with Kaplan-Meier log-rank test and Cox proportional hazards methodologies.

RESULTS

An overwhelming 93.8% of patients carried druggable mutations in NSCLC LM, with EGFR (78.8%) being the most prevalent. Notably, 4 patients who tested negative for driver genes in extracranial samples surprisingly showed EGFR mutations in their CSF and subsequently benefited from targeted therapy. There was a clear difference in genetic profiles between CSF and extracranial samples, with CSF showing more driver gene detections, increased Copy Number Variations (CNVs), and varied resistance mechanisms among individuals. Abnormalities in cell-cycle regulatory molecules were highly enriched in LM (50.9% vs 31.0%, p = 0.017), and CDKN2A/2B deletions were identified as an independent poor prognostic factor for LM patients, with a significant reduction in median OS (p = 0.013), supported by multivariate analysis (HR 2.63, 95% CI 1.32-5.26, p = 0.006).

CONCLUSIONS

CSF-based ctDNA analysis is crucial for detecting and characterizing genetic alterations in NSCLC LM. The distinct genetic profiles in CSF and extracranial tissues emphasize the need for personalized treatment approaches.

Root Extract of Trichosanthes kirilowii Suppresses Metastatic Activity of EGFR TKI-Resistant Human Lung Cancer Cells by Inhibiting Src-Mediated EMT

The roots of Trichosanthes kirilowii (TK) have been used in traditional oriental medicine for the treatment of respiratory diseases. In this study, we investigated whether an ethanolic root extract of TK (ETK) can regulate the metastatic potency of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI)-resistant human lung cancer cells. The relative migration and invasion abilities of erlotinib-resistant PC9 (PC9/ER) and gefitinib-resistant PC9 (PC9/GR) cells were higher than those of parental PC9 cells. Mesenchymal markers were overexpressed, whereas epithelial markers were downregulated in resistant cells, suggesting that resistant cells acquired the EMT phenotype. ETK reduced migration and invasion of resistant cells. The expression levels of N-cadherin and Twist were downregulated, whereas Claudin-1 was upregulated by ETK, demonstrating that ETK suppresses EMT. As a molecular mechanism, Src was dephosphorylated by ETK. The anti-metastatic effect of ETK was reduced by transfecting PC9/ER cells with a constitutively active form of c-Src. Dasatinib downregulated N-cadherin, Twist, and vimentin, suggesting that Src regulates EMT in resistant cells. Notably, CuB played a key role in mediating the anti-metastatic activity of ETK. Collectively, our results demonstrate that ETK can attenuate the metastatic ability of EGFR-TKI-resistant lung cancer cells by inhibiting Src-mediated EMT.

Circ_16601 facilitates Hippo pathway signaling via the miR-5580-5p/FGB axis to promote my-CAF recruitment in the TME and LUAD progression

BACKGROUND

Lung cancer represents a significant public health issue in China, given its high incidence and mortality rates. Circular RNAs (circRNAs) have been recently proposed to participate in the development and progression of tumors. Nevertheless, their particular roles in the pathogenesis of lung adenocarcinoma (LUAD), the tumor microenvironment (TME), and the underlying molecular mechanisms are still not well understood.

METHODS

High-throughput sequencing was used to analyze the circRNAs expression profiles in 7 pairs of human LUAD tissues. shRNA was used to knockdown the YAP1 and FGB genes. RNA sequencing and RT-qPCR were performed to classify the regulatory effects of circ_16601 in LUAD cells. The progression effect of circ_16601 on lung cancer was investigated in vitro and in vivo.

RESULTS

The circ_16601 is significantly elevated in LUAD tissues compared to adjacent normal lung tissues, and its high expression is positively associated with poor prognosis in LUAD patients. Additionally, circ_16601 overexpression promotes LUAD cell proliferation in vitro and increases xenograft tissue growth in mice in vivo; circ_16601 also could recruit fibroblasts to cancer associate fibroblasts. Mechanistically, circ_16601 can directly bind to miR-5580-5p, preventing its ability to degrade FGB mRNA and enhancing its stability. Subsequently, circ_16601 promotes the activation of the Hippo pathway in a YAP1-dependent manner, leading to LUAD progression.

CONCLUSIONS

Our findings shed valuable insights into the regulatory role of circ_16601 in LUAD progression and highlight its potential as a diagnostic and therapeutic target in LUAD. Overall, this study provides theoretical support to improve the prognosis and quality of life of patients suffering from this devastating disease.

Comparison of gene mutation profile in different lung adenocarcinoma subtypes by targeted next-generation sequencing

BACKGROUND

Disease prognosis after resection of lung cancer could be affected by pathological subtypes. In this study, we investigated the difference of gene variation and significantly altered pathways between adenocarcinoma in situ (AIS)/microinvasive adenocarcinoma (MIA) and invasive adenocarcinoma (IAC) subtypes to reveal the molecular mechanism of prognosis differences.

METHODS

Sixty one tumor tissues were subjected to DNA extraction and customized 136 gene targeted next-generation sequencing. Comparisons between groups were performed with two-sided Fisher's exact test for categorical variables and two-tailed unpaired t test for numerical variables.

RESULTS

A total of 402 somatic mutations involved in 70 genes were detected in all these samples, and 74.29% of these genes were mutated in at least two samples. PMS2, ARID1A, EGFR, and POLE were the most frequently mutated genes. ALK_EML4 fusion was observed in one IAC patient and RET_ KIF5B fusion in one AIS patient. A significant higher proportion of patients with TP53 gene mutation was observed in the IAC group (P = 0.0057). The average onset age in IAC group is 62.48 years, which is greater than other subtypes (P = 0.0166). It revealed that mutations in genes involved in the mTOR signaling pathway (56.52% vs 26.32%, P = 0.0288) and Hippo signaling pathway (34.78% vs 10.53%, P = 0.0427) were significantly enriched in IAC subtypes, suggesting the key involvement of mTOR and Hippo signaling pathways in lung tumor development and malignant progression.

CONCLUSIONS

This study revealed the heterogeneity of gene mutations and significantly altered pathways between different lung cancer subtypes, suggesting the potential mechanism of different prognosis.

Suppressing c-FOS expression by G-quadruplex ligands inhibits osimertinib-resistant non-small cell lung cancer

BACKGROUND

Osimertinib is the first-line therapy for patients with non-small cell lung cancer harboring epidermal growth factor receptor-activating alterations. Although osimertinib has been shown to elicit profound patient responses, cancer cells frequently develop additional alterations that sustain their proliferation capacity. This acquired resistance represents a substantial hurdle in precision medicine for patients with lung cancer.

METHODS

The biological and cellular properties of the G-quadruplex ligand BMVC-8C3O and its anticancer activities were evaluated in non-small cell lung carcinomas. In addition, combined treatment with BMVC-8C3O and osimertinib was evaluated for its effects on the growth of osimertinib-resistant tumors in vivo.

RESULTS

We demonstrate that BMVC-8C3O effectively suppresses c-FOS expression by stabilizing G-rich sequences located at the c-FOS promoter. The suppression c-FOS expression by BMVC-8C3O increases the sensitivity of acquired resistant cancer cells to osimertinib. Combining BMVC-8C3O and osimertinib has a synergistic effect in inhibiting the growth of acquired resistant cancers both in vitro and in mouse models. The combined inhibitory effect is not limited to BMVC-8C3O, either: several G-quadruplex ligands show varying levels of inhibition activity. We also show that simultaneous inhibition of both the c-FOS and PI3K/AKT pathways by BMVC-8C3O and osimertinib synergistically inhibits the growth of acquired resistant cancer cells.

CONCLUSION

These findings unveil a synthetic lethal strategy to prevent and inhibit epidermal growth factor receptor-altered lung cancers with acquired osimertinib resistance. G-quadruplex ligands have the potential to be integrated into current osimertinib-based treatment regimens.

20 years since the approval of first EGFR-TKI, gefitinib: Insight and foresight

Epidermal growth factor receptor (EGFR) actively involves in modulation of various cancer progression related mechanisms including angiogenesis, differentiation and migration. Therefore, targeting EGFR has surfaced as a prominent approach for the treatment of several types of cancers, including non-small cell lung cancer (NSCLC), pancreatic cancer, glioblastoma. Various first, second and third generation of EGFR tyrosine kinase inhibitors (EGFR-TKIs) have demonstrated effectiveness as an anti-cancer therapeutics. However, rapid development of drug resistance and mutations still remains a major challenge for the EGFR-TKIs therapy. Overcoming from intrinsic and acquired resistance caused by EGFR mutations warrants the further exploration of alternative strategies and discovery of novel inhibitors. In this review, we delve into the breakthrough discoveries have been made in previous 20 years, and discuss the currently ongoing efforts aimed to circumvent the chemo-resistance. We also highlight the new challenges, limitations and future directions for the development of improved therapeutic approaches such as fourth-generation EGFR-TKIs, peptides, nanobodies, PROTACs etc.

Association between pretreatment C-reactive protein level and survival in non-small cell lung cancer patients treated with immune checkpoint inhibitors: A meta-analysis

BACKGROUND

Current evidence suggests that C-reactive protein (CRP) levels may affect cancer prognosis. However, the effect of CRP has not been validated in immunotherapy recipients with non-small cell lung cancer (NSCLC). Therefore, we performed a meta-analysis to explore the prognostic value of CRP level in patients with NSCLC treated with immune checkpoint inhibitors.

METHODS

PubMed, Web of Science, Embase, and Scopus databases were systematically retrieved for eligible publications, and hazard ratios (HRs) with corresponding 95% confidence intervals (95%CIs) were extracted and merged to evaluate the correlation between pretreatment CRP levels and overall survival (OS) and progression-free survival (PFS). Subgroup and sensitivity analyses were conducted to confirm these findings.

RESULTS

Thirty-five cohorts consisting of 4698 patients were included in the primary analysis. Pooled results demonstrated that a higher pretreatment CRP level is associated with worse OS and PFS (OS: HR = 1.13, 95 %CI:1.09-1.18; PFS: HR = 1.16, 95 %CI:1.10-1.22). These findings remained robust after further statistical analyses.

CONCLUSION

Pretreatment CRP level could be a promising biomarker for NSCLC immunotherapy. However, prospective studies are required to validate these findings.

Comprehensive genomic profiling of Japanese patients with thoracic malignancies: A single-center retrospective study

BACKGROUND

Few studies have been conducted on comprehensive genomic profiling (CGP) panels in Japanese patients with thoracic malignancies after completing standard treatment. Consequently, its value in clinical practice remains unclear.

METHODS

We conducted a retrospective study of Japanese patients with thoracic malignancies who underwent CGP between June 2019 and November 2022 at our hospital. We evaluated the detection rate of actionable genetic alterations and percentage of patients who received genomically-matched therapy. Furthermore, we examined the value of the CGP panel in patients who underwent multiplex gene-panel testing prior to their initial treatment. This study was performed in accordance with the principles of the Declaration of Helsinki.

RESULTS

The study included 56 patients, of whom 47 (83.9%) had actionable genetic alterations and 8 (14.3%) received genomically-matched therapy. Of these, four patients were treated with approved drugs and three patients were treated with investigational agents. In addition, one patient was treated with approved drugs using the patient-directed care system. Of the 17 patients who had multiplex gene-panel testing performed at the start of their initial therapy, two (11.8%) were newly identified by the CGP panel and subsequently received genomically-matched therapy. EGFR L718Q and MET amplification were observed in two of the seven patients with epidermal growth factor receptor-tyrosine kinase inhibitor resistance.

CONCLUSIONS

The CGP panel could identify genetic alterations, thereby facilitating genomically-matched therapy, even in patients with thoracic malignancies who could not be identified using multiplex gene-panel testing.

Local control strategies for management of NSCLC with oligoprogressive disease

Progresses of systemic treatments in advanced non-small cell lung cancer (NSCLC), such as immune checkpoint blockers (ICB) and targeted therapies, led to the increased incidence of oligoprogressive disease (OPD). The OPD is a subtype of oligometastatic disease (OMD) defined as a progression of a limited number of lesions during systemic treatment exposure. The hypothesis was formulated that local radical treatments (LRT) could eradicate progressive lesions resulting from resistant clones, ultimately leading to systemic treatment sensitivity restoration. Recently published international consensuses and guidelines aim to obtain a uniform definition of OMD NSCLC, to standardize the inclusion of these patients in future clinical trials, as well as their management in daily practice. Although there is no specific definition of OPD, LRT strategies in OPD are supported after reporting promising results. Both retrospective and preliminary prospective randomized data of LRT for patients with OPD NSCLC are encouraging. More clinical and translational data are needed for selecting best scenarios where LRT should be delivered. In this review, we analyze the current available literature on LRT for patients with OPD in advanced NSCLC and discuss about future trial design and challenges.

EGFR TKI resistance in lung cancer cells using RNA sequencing and analytical bioinformatics tools

Epidermal Growth Factor Receptor (EGFR) signaling and EGFR mutations play key roles in cancer pathogenesis, particularly in the development of drug resistance. For the ∼20% of all non-small cell lung cancer (NSCLC) patients that harbor an activating mutation, EGFR tyrosine kinase inhibitors (TKIs) provide initial clinical responses. However, long-term efficacy is not possible due to acquired drug resistance. Despite a gradually increasing knowledge of the mechanisms underpinning the development of resistance in tumors, there has been very little success in overcoming it and it is probable that many additional mechanisms are still unknown. Herein, publicly available RNASeq (RNA sequencing) datasets comparing lung cancer cell lines treated with EGFR TKIs until resistance developed with their corresponding parental cells and protein array data from our own EGFR TKI treated xenograft tumors, were analyzed for differential gene expression, with the intent to investigate the potential mechanisms of drug resistance to EGFR TKIs. Pathway analysis, as well as structural disorder analysis of proteins in these pathways, revealed several key proteins, including DUSP1, DUSP6, GAB2, and FOS, that could be targeted using novel combination therapies to overcome EGFR TKI resistance in lung cancer.

Comparison and Validation of Rapid Molecular Testing Methods for Theranostic Epidermal Growth Factor Receptor Alterations in Lung Cancer: Idylla versus Digital Droplet PCR

Targeting EGFR alterations, particularly the L858R (Exon 21) mutation and Exon 19 deletion (del19), has significantly improved the survival of lung cancer patients. From now on, the issue is to shorten the time to treatment. Here, we challenge two well-known rapid strategies for EGFR testing: the cartridge-based platform Idylla™ (Biocartis) and a digital droplet PCR (ddPCR) approach (ID_Solution). To thoroughly investigate each testing performance, we selected a highly comprehensive cohort of 39 unique del19 (in comparison, the cbioportal contains 40 unique del19), and 9 samples bearing unique polymorphisms in exon 19. Additional L858R (N = 24), L861Q (N = 1), del19 (N = 63), and WT samples (N = 34) were used to determine clear technical and biological cutoffs. A total of 122 DNA samples extracted from formaldehyde-fixed samples was used as input. No false positive results were reported for either of the technologies, as long as careful droplet selection (ddPCR) was ensured for two polymorphisms. ddPCR demonstrated higher sensitivity in detecting unique del19 (92.3%, 36/39) compared to Idylla (67.7%, 21/31). However, considering the prevalence of del19 and L858R in the lung cancer population, the adjusted theranostic values were similar (96.51% and 95.26%, respectively). ddPCR performs better for small specimens and low tumoral content, but in other situations, Idylla is an alternative (especially if a molecular platform is absent).

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.

New Generations of Tyrosine Kinase Inhibitors in Treating NSCLC with Oncogene Addiction: Strengths and Limitations

Tyrosine kinase inhibitors (TKIs) revolutionized the treatment of patients with advanced or metastatic non-small cell lung cancer (NSCLC) harboring most driver gene alterations. Starting from the first generation, research rapidly moved to the development of newer, more selective generations of TKIs, obtaining improved results in terms of disease control and survival. However, the use of novel generations of TKIs is not without limitations. We reviewed the main results obtained, as well as the ongoing clinical trials with TKIs in oncogene-addicted NSCLC, together with the biology underlying their potential strengths and limitations. Across driver gene alterations, novel generations of TKIs allowed delayed resistance, prolonged survival, and improved brain penetration compared to previous generations, although with different toxicity profiles, that generally moved their use from further lines to the front-line treatment. However, the anticipated positioning of novel generation TKIs leads to abolishing the possibility of TKI treatment sequencing and any role of previous generations. In addition, under the selective pressure of such more potent drugs, resistant clones emerge harboring more complex and hard-to-target resistance mechanisms. Deeper knowledge of tumor biology and drug properties will help identify new strategies, including combinatorial treatments, to continue improving results in patients with oncogene-addicted NSCLC.

The effect of PLK1 inhibitor in osimertinib resistant non-small cell lung carcinoma cells

OBJECTIVES

To investigate the effects of PLK1 inhibitors on osimertinib-resistant non-small cell lung carcinoma (NSCLC) cells and the anti-tumor effect combined with osimertinib.

METHODS

An osimertinib resistant NCI-H1975 cell line was induced by exposure to gradually increasing drug concentrations. Osimertinib-resistant cells were co-treated with compounds from classical tumor pathway inhibitor library and osimertinib to screen for compounds with synergistic effects with osimertinib. The Gene Set Enrichment Analysis (GSEA) was used to investigate the activated signaling pathways in osimertinib-resistant cells; sulforhodamine B (SRB) staining was used to investigate the effect of PLK1 inhibitors on osimertinib-resistant cells and the synergistic effect of PLK1 inhibitors combined with osimertinib.

RESULTS

Osimertinib-resistance in NCI-H1975 cell (resistance index=43.45) was successfully established. The PLK1 inhibitors GSK 461364 and BI 2536 had synergistic effect with osimertinib. Compared with osimertinib-sensitive cells, PLK1 regulatory pathway and cell cycle pathway were significantly activated in osimertinib-resistant cells. In NSCLC patients with epidermal growth factor receptor mutations treated with osimertinib, PLK1 mRNA levels were negatively correlated with progression free survival of patients (R=－0.62, P<0.05), indicating that excessive activation of PLK1 in NSCLC cells may cause cell resistant to osimertinib. Further in vitro experiments showed that IC50 of PLK1 inhibitors BI 6727 and GSK 461364 in osimertinib-resistant cells were lower than those in sensitive ones. Compared with the mono treatment of osimertinib, PLK1 inhibitors combined with osimertinib behaved significantly stronger effect on the proliferation of osimertinib-resistant cells.

CONCLUSIONS

PLK1 inhibitors have a synergistic effect with osimertinib on osimertinib-resistant NSCLC cells which indicates that they may have potential clinical value in the treatment of NSCLC patients with osimertinib resistance.

Resistance of Lung Cancer to EGFR-Specific Kinase Inhibitors: Activation of Bypass Pathways and Endogenous Mutators

Epidermal growth factor receptor (EGFR)-specific tyrosine kinase inhibitors (TKIs) have changed the landscape of lung cancer therapy. For patients who are treated with the new TKIs, the current median survival exceeds 3 years, substantially better than the average 20 month survival rate only a decade ago. Unfortunately, despite initial efficacy, nearly all treated patients evolve drug resistance due to the emergence of either new mutations or rewired signaling pathways that engage other receptor tyrosine kinases (RTKs), such as MET, HER3 and AXL. Apparently, the emergence of mutations is preceded by a phase of epigenetic alterations that finely regulate the cell cycle, bias a mesenchymal phenotype and activate antioxidants. Concomitantly, cells that evade TKI-induced apoptosis (i.e., drug-tolerant persister cells) activate an intrinsic mutagenic program reminiscent of the SOS system deployed when bacteria are exposed to antibiotics. This mammalian system imbalances the purine-to-pyrimidine ratio, inhibits DNA repair and boosts expression of mutation-prone DNA polymerases. Thus, the net outcome of the SOS response is a greater probability to evolve new mutations. Deeper understanding of the persister-to-resister transformation, along with the development of next-generation TKIs, EGFR-specific proteolysis targeting chimeras (PROTACs), as well as bispecific antibodies, will permit delaying the onset of relapses and prolonging survival of patients with EGFR+ lung cancer.

JMJD5 inhibits lung cancer progression by facilitating EGFR proteasomal degradation

Aberrant activation of epidermal growth factor receptor (EGFR) signaling is closely related to the development of non-small cell lung cancer (NSCLC). However, targeted EGFR therapeutics such as tyrosine kinase inhibitors (TKIs) face the challenge of EGFR mutation-mediated resistance. Here, we showed that the reduced JmjC domain-containing 5 (JMJD5) expression is negatively associated with EGFR stability and NSCLC progression. Mechanically, JMJD5 cooperated with E3 ligase HUWE1 to destabilize EGFR and EGFR TKI-resistant mutants for proteasomal degradation, thereby inhibiting NSCLC growth and promoting TKI sensitivity. Furthermore, we identified that JMJD5 can be transported into recipient cells via extracellular vesicles, thereby inhibiting the growth of NSCLC. Together, our findings demonstrate the tumor-suppressive role of JMJD5 in NSCLC and suggest a putative therapeutic strategy for EGFR-related NSCLC by targeting JMJD5 to destabilize EGFR.

Precision Oncology Comes of Age: Designing Best-in-Class Small Molecules by Integrating Two Decades of Advances in Chemistry, Target Biology, and Data Science

Small-molecule drugs have enabled the practice of precision oncology for genetically defined patient populations since the first approval of imatinib in 2001. Scientific and technology advances over this 20-year period have driven the evolution of cancer biology, medicinal chemistry, and data science. Collectively, these advances provide tools to more consistently design best-in-class small-molecule drugs against known, previously undruggable, and novel cancer targets. The integration of these tools and their customization in the hands of skilled drug hunters will be necessary to enable the discovery of transformational therapies for patients across a wider spectrum of cancers.

SIGNIFICANCE

Target-centric small-molecule drug discovery necessitates the consideration of multiple approaches to identify chemical matter that can be optimized into drug candidates. To do this successfully and consistently, drug hunters require a comprehensive toolbox to avoid following the "law of instrument" or Maslow's hammer concept where only one tool is applied regardless of the requirements of the task. Combining our ever-increasing understanding of cancer and cancer targets with the technological advances in drug discovery described below will accelerate the next generation of small-molecule drugs in oncology.