Treatments for EGFR-mutant non-small cell lung cancer (NSCLC): The road to a success, paved with failures

Design, synthesis and biological evaluation of a new series of imidazothiazole-hydrazone hybrids as dual EGFR and Akt inhibitors for NSCLC therapy

In search of small molecules for targeted therapy of non-small cell lung carcinoma (NSCLC), an efficient four-step synthetic route was followed for the synthesis of new imidazothiazole-hydrazone hybrids, which were assessed for their cytotoxic effects on human lung adenocarcinoma (A549) and human lung fibroblast (CCD-19Lu) cells. Among them, compounds 4, 6, 13, 16, 17 and 21 exhibited selective cytotoxic activity against A549 cell line. In vitro mechanistic studies were performed to assess their effects on apoptosis, caspase-3, cell cycle, EGFR and Akt in A549 cells. Compounds 6, 16, 17 and 21 promoted apoptotic cell death more than erlotinib. According to the in vitro data, it is quite clear that compound 6 promotes apoptosis through caspase-3 activation and arrests the cell cycle at the G0/G1 phase in A549 cells. Compounds 16 and 17 arrested the cell cycle at the S phase, whereas compounds 4, 13 and 21 caused the cell cycle arrest at the G2/M phase. The most effective EGFR inhibitor in this series was found as compound 13, followed by compounds 17 and 16. Furthermore, Akt inhibitory effects of compounds 16 and 17 in A549 cells were close to that of GSK690693. In particular, it can be concluded that the cytotoxic and apoptotic effects of compounds 16 and 17 are associated with their inhibitory effects on both EGFR and Akt. Molecular docking studies suggest that compounds 16 and 17 interact with crucial amino acid residues in the binding sites of human EGFR (PDB ID: 1M17) and Akt2 (PDB ID: 3D0E). Based on the in silico data, both compounds are predicted to possess favorable oral bioavailability and drug-likeness. Further studies are required to benefit from these compounds as anticancer agents for targeted therapy of NSCLC.

Mechanisms of resistance to tyrosine kinase inhibitor-targeted therapy and overcoming strategies

Tyrosine kinase inhibitor (TKI)-targeted therapy has revolutionized cancer treatment by selectively blocking specific signaling pathways crucial for tumor growth, offering improved outcomes with fewer side effects compared with conventional chemotherapy. However, despite their initial effectiveness, resistance to TKIs remains a significant challenge in clinical practice. Understanding the mechanisms underlying TKI resistance is paramount for improving patient outcomes and developing more effective treatment strategies. In this review, we explored various mechanisms contributing to TKI resistance, including on-target mechanisms and off-target mechanisms, as well as changes in the tumor histology and tumor microenvironment (intrinsic mechanisms). Additionally, we summarized current therapeutic approaches aiming at circumventing TKI resistance, including the development of next-generation TKIs and combination therapies. We also discussed emerging strategies such as the use of dual-targeted antibodies and PROteolysis Targeting Chimeras. Furthermore, we explored future directions in TKI-targeted therapy, including the methods for detecting and monitoring drug resistance during treatment, identification of novel targets, exploration of dual-acting kinase inhibitors, application of nanotechnologies in targeted therapy, and so on. Overall, this review provides a comprehensive overview of the challenges and opportunities in TKI-targeted therapy, aiming to advance our understanding of resistance mechanisms and guide the development of more effective therapeutic approaches in cancer treatment.

Custom-Designed Probes for the Accurate Determination of Epidermal Growth Factor Receptor Mutations and Their Allelic Configuration

The identification of single nucleotide polymorphisms (SNPs) is of paramount importance for disease diagnosis and clinical prognostication. In the context of nonsmall cell lung cancer (NSCLC), the emergence of resistance mutations, exemplified by the epidermal growth factor receptor (EGFR) T790 M and C797S, is intricately linked to the therapeutic efficacy of EGFR tyrosine kinase inhibitors (EGFR-TKIs). Herein, a highly efficient and specific SNP detection platform for T790 M and C797S mutations has been engineered through the integration of an asymmetric polymerase chain reaction (PCR) and an ingeniously tailored four-way junction (4WJ) probe. Notably, a molecular beacon (MB) probe was judiciously designed to discern the allelic configuration of these mutations. The administration of first- and third-generation EGFR-TKIs demonstrates therapeutic efficacy solely when the mutations are in the trans configuration, characterized by a low fluorescence signal. In contrast, significant fluorescence by the MB probe is indicative of the C797S mutation being in a cis arrangement with T790M, thereby rendering the cells refractory to the therapeutic interventions of both first- and third-generation EGFR-TKIs. The assay is capable of concurrently detecting two point-mutations and ascertaining their allelic positions in a single test within 1.5 h, enhancing both efficiency and simplicity. It also exhibits high accuracy in the identification of clinical samples, offering promising implications for therapeutic guidelines. By enabling tailored treatment plans based on specific genetic profiles, our approach not only advances the precision of NSCLC treatment strategies but also marks a significant contribution to personalized medicine.

Addition of bevacizumab to EGFR tyrosine kinase inhibitors in advanced NSCLC: an updated systematic review and meta-analysis

Background: The synergistic effects of antiangiogenic inhibitor bevacizumab and epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) therapy were encouraging in patients with EGFR-mutant advanced NSCLC, though some controversy remains. The specific subgroup of patients who might benefit most from the EGFR-TKI and bevacizumab combination therapy is yet to be determined. Methods: Randomized clinical trials (RCTs) that had compared the clinical efficacy of EGFR-TKI and bevacizumab combination therapy with EGFR-TKI monotherapy in treating EGFR-mutant advanced NSCLC patients published before 23 December 2022 were searched in the Cochrane, PubMed and Embase. We performed a meta-analysis for the overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and treatment-related adverse events with a grade equal or more than 3 (grade≥3 TRAEs). Subgroup analyses of PFS and OS stratified by clinical characteristics and treatment were conducted. Results: We included 10 RCTs involving 1520 patients. Compared with EGFR-TKI monotherapy, addition of bevacizumab to EGFR-TKI resulted in a significantly higher PFS (hazard ratio (HR) = 0.74, 95% confidence interval (95% CI): 0.62-0.87)) and ORR (risk ratio (RR) = 1.07, 95% CI: 1.01-1.13). However, no significant difference in OS (HR = 0.96, 95% CI: 0.83-1.12) was noticed. Patients with EGFR-mutant advanced NSCLC receiving combination therapy showed PFS improvement regardless of gender (male or female), Eastern Cooperative Oncology Group performance status (0 or 1), baseline central nervous system (CNS) metastasis (presence or absence) and EGFR mutation type (19del or 21L858R). Subgroup analyses showed that, with the treatment of bevacizumab and EGFR-TKI, patients who ever smoked achieved significantly better OS and PFS benefits (HR = 0.68, 95% CI: 0.48-0.95; HR = 0.59, 95% CI: 0.46-0.74, respectively), and those aged <75 years and the Asian population had significantly prolonged PFS (HR = 0.69, 95% CI: 0.52-0.91; HR = 0.71, 95% CI: 0.58-0.87; respectively). The superiority of EGFR-TKI and bevacizumab combination therapy against EGFR-TKI monotherapy in improving PFS was more significant in the erlotinib regimen subgroup. The risk of grade≥3 TRAEs was remarkably higher in the combination therapy group (HR = 1.73, 95% CI: 1.39-2.16). Conclusion: Addition of bevacizumab to EGFR-TKI therapy provided significantly better PFS and ORR for EGFR-mutant advanced NSCLC patients, though with higher risk of grade≥3 TRAEs. Patients who ever smoked, aged <75 years, and Asian population might benefit more from the combination regimen. Systematic Review Registration: This systematic review and meta-analysis was registered in the PROSPERO database (CRD42023401926).

Sijunzi Tang improves gefitinib resistance by regulating glutamine metabolism

Lung cancer is a major health concern and significant barrier to human well-being and social development. Although targeted therapy has shown remarkable progress in the treatment of lung cancer, the emergence of drug resistance has limited its clinical efficacy. Sijunzi Tang (SJZ) is a classical Chinese herbal formula known for tonifying qi and nourishing the lungs, has been recognized for its potential in lung cancer management. However, the underlying mechanism of its combined use with anti-cancer drugs remains unclear. Here, we investigated the anti-lung cancer efficacy and underlying mechanisms of the combination of gefitinib and SJZ in gefitinib-resistant human lung adenocarcinoma cells (PC-9/GR). We conducted in vitro and in vivo experiments using histopathology and targeted metabolomics approaches. Our results demonstrated that the combination of SJZ and gefitinib exhibited synergistic effects on tumor growth inhibition in PC-9/GR-bearing nude mice. Notably, the co-administration of SJZ and gefitinib synergistically promoted tumor cell apoptosis, potentially through the regulation of BAX and BCL-2 expression. Immunohistochemistry and western blot analysis found down-regulation of GLS, GS, and SLC1A5 expression in the co-administration group compared to the control and the individual treatment groups. Targeted metabolomics revealed significant alterations in the plasma glutamine metabolic markers glutamine, alanine, succinate, glutamate, and pyruvate. Of the glutamine metabolism markers measured in tumor tissues, glutamine and pyruvate demonstrated significant differences across the treatment groups. These findings suggest that administration of SJZ improves gefitinib resistance in the treatment of lung cancer without toxic effects. Moreover, SJZ may affect glutamine metabolism by regulating key targets involved in glutamine metabolism (SLC1A5, GLS, and GS) and modulating the levels of related metabolic markers, ultimately reducing gefitinib resistance.

EGFR-T790M Mutation-Derived Interactome Rerouted EGFR Translocation Contributing to Gefitinib Resistance in Non-Small Cell Lung Cancer

Secondary mutation, T790M, conferring tyrosine kinase inhibitors (TKIs) resistance beyond oncogenic epidermal growth factor receptor (EGFR) mutations presents a challenging unmet need. Although TKI-resistant mechanisms are intensively investigated, the underlying responses of cancer cells adapting drug perturbation are largely unknown. To illuminate the molecular basis linking acquired mutation to TKI resistance, affinity purification coupled mass spectrometry was adopted to dissect EGFR interactome in TKI-sensitive and TKI-resistant non-small cell lung cancer cells. The analysis revealed TKI-resistant EGFR-mutant interactome allocated in diverse subcellular distribution and enriched in endocytic trafficking, in which gefitinib intervention activated autophagy-mediated EGFR degradation and thus autophagy inhibition elevated gefitinib susceptibility. Alternatively, gefitinib prompted TKI-sensitive EGFR translocating toward cell periphery through Rab7 ubiquitination which may favor efficacy to TKIs suppression. This study revealed that T790M mutation rewired EGFR interactome that guided EGFR to autophagy-mediated degradation to escape treatment, suggesting that combination therapy with TKI and autophagy inhibitor may overcome acquired resistance in non-small cell lung cancer.

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

Resistance to epidermal growth factor tyrosine kinase inhibitors (EGFR-TKI) remains one of the major challenges in lung adenocarcinoma (LUAD) therapy. Here, we find an increased frequency of the L12_16 amino acid deletion mutation in the signal peptide region of NOTCH4 (NOTCH4^ΔL12_16) in EGFR-TKI-sensitive patients. Functionally, exogenous induction of NOTCH4^ΔL12_16 in EGFR-TKI -resistant LUAD cells sensitizes them to EGFR-TKIs. This process is mainly mediated by the reduction of the intracellular domain of NOTCH4 (NICD4) caused by the NOTCH4^ΔL12_16 mutation, which results in a lower localization of NOTCH4 in the plasma membrane. Mechanistically, NICD4 transcriptionally upregulates the expression of HES1 by competitively binding to the gene promoter relative to p-STAT3. Because p-STAT3 can downregulate the expression of HES1 in EGFR-TKI-resistant LUAD cells, the reduction of NICD4 induced by NOTCH4^ΔL12_16 mutation leads to a decrease in HES1. Moreover, inhibition of the NOTCH4-HES1 pathway using inhibitors and siRNAs abolishes the resistance of EGFR-TKI. Overall, we report that the NOTCH4^ΔL12_16 mutation sensitizes LUAD patients to EGFR-TKIs through transcriptional down-regulation of HES1 and that targeted blockade of this signaling cohort could reverse EGFR-TKI -resistance in LUAD, providing a potential approach to overcome resistance to EGFR-TKI -therapy.

Drug-drug interaction potential of SH-1028, a third-generation EGFR-TKI: in vitro and clinical trials

SH-1028 is an irreversible third-generation EGFR tyrosine kinase inhibitor (EGFR-TKI) for the treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC). Considering the possibility of combination therapy in patients with NSCLC, we investigated the drug-drug interaction (DDI) potential of SH-1028 both in vitro and in clinical trials. The in vitro studies were conducted to determine the potential of SH-1028 as a substrate, inducer, or inhibitor of cytochrome P450 (CYP) subtypes. A phase I drug-drug interaction study in healthy volunteers was performed to evaluate the impact of co-administering rifampicin (a strong CYP3A4 inducer) and itraconazole (a strong CYP3A4 inhibitor) on the pharmacokinetics of SH-1028. The in vitro experiments showed that SH-1028 was mainly metabolized by CYP3A4. The activities of CYP1A2, 2B6, 2C19, 2D6 and 3A4 enzymes were slightly inhibited in vitro with SH-1028. SH-1028 has no obvious induction effect on CYP1A2 and CYP2B6 activities, but has potential induction effect on CYP3A4 mRNA expression. However, SH-1028 may not induce or inhibit human CYPs significantly at the clinically expected dose (200 mg). The geometric mean ratios of pharmacokinetic parameters and their corresponding 90% confidence intervals for SH-1028 in combination and alone did not fall within the range of 80-125%. It is speculated that itraconazole and rifampicin affect the metabolism of SH-1028. In the clinical application of SH-1028, special attention should be paid to the interaction between SH-1028 and drugs or foods that affect the activity of CYP3A4. (Clinical trial registration number: CTR20210558).

Forkhead box L2 is a target of miR-133b and plays an important role in the pathogenesis of non-small cell lung cancer

BACKGROUND

Forkhead box L2 (FOXL2) has been recognized as a transcription factor in the progression of many malignancies, but its role in non-small cell lung cancer (NSCLC) remains unclear. This research clarified on the role of FOXL2 and the specific molecular mechanism in NSCLC.

METHODS

RNA and protein levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting assays. Cell proliferation was examined by cell counting kit-8 (CCK-8) and clonogenic assays. Transwell and wound healing assays were used to detect cell invasion and migration. Cell cycle alterations were assessed by flow cytometry. The relationship between FOXL2 and miR-133b was verified by dual-luciferase reporter assays. In vivo metastasis was monitored in the tail vein-injected mice.

RESULTS

FOXL2 was upregulated in NSCLC cells and tissues. Downregulation of FOXL2 restrained cell proliferation, migration, and invasion and arrested the cell cycle of NSCLC cells. Moreover, FOXL2 promoted the epithelial-mesenchymal transition (EMT) process of NSCLC cells by inducing the transforming growth factor-β (TGF-β)/Smad signaling pathway. miR-133b directly targeted the 3'-UTR of FOXL2 and negatively regulated FOXL2 expression. Knockdown of FOXL2 blocked metastasis in vivo.

CONCLUSIONS

miR-133b downregulates FOXL2 by targeting the 3'-UTR of FOXL2, thereby inhibiting cell proliferation, EMT and metastasis induced by the TGF-β/Smad signaling pathway in NSCLC. FOXL2 may be a potential molecular target for treating NSCLC.

Safety, efficacy, and pharmacokinetics of SH-1028 in EGFR T790M-positive advanced non-small cell lung cancer patients: A dose-escalation phase 1 study

BACKGROUND

SH-1028 is a new third-generation EGFR tyrosine kinase inhibitors (TKI) to benefit patients with EGFR T790M-mutated NSCLC. Here, the authors report its clinical safety, preliminary efficacy, and pharmacokinetic (PK) profile for the first time.

METHODS

Patients with EGFR T790M mutation, locally advanced non-small cell lung cancer (NSCLC), or metastatic NSCLC who had progressed after previous EGFR TKI therapy were eligible. Patients received SH-1028 at five oral dose levels (60 mg, 100 mg, 200 mg, 300 mg, and 400 mg) once daily until disease progression, unacceptable toxicity, or patient withdrawal. The primary end points were the safety, dose-limiting toxicity (DLT), maximum-tolerated dose (MTD), and PK profile. Secondary end points included objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), etc. RESULTS: Data cut off on December 31, 2020, a total of 20 patients were enrolled during the trial, two of three patients in 300 mg cohort experienced a DLT, and no DLT was observed in 240 mg cohort, 240 mg was determined to be the MTD of SH-1028. A total of 95.0% (19 of 20) of patients reported treatment-related adverse events (TRAEs), and the incidence of serious adverse events was 20.0% (4 of 20). The ORR and DCR of the 200 mg cohort were 75% (95% confidence interval [CI], 19.41-99.37) and 75.0% (95% CI, 19.41-99.37), respectively. The overall ORR was 40% (95% CI, 19.12-63.95), and DCR was 70.0% (95% CI, 45.72-88.11). According to the PK profile, the dosage regimen for future studies was determined as 200 mg once daily.

CONCLUSIONS

SH-1028 showed a manageable safety and promising antitumor activity in patients with EGFR T790M mutation at the dose of 200 mg once daily.

PLAIN LANGUAGE SUMMARY

Lung cancer has a high morbidity and mortality, with an estimated 1.8 million deaths in 2020. Non-small cell lung cancer accounts for approximately 85% of lung cancer. First- or second-generation EGFR TKIs' weak selectivity often led to the occurrence of treatment-related adverse events, such as interstitial lung disease, rash, diarrhea, etc., along with acquired drug resistance within approximately 1 year. A dose of 200 mg of SH-1028 once daily showed a preliminary antitumor activity with manageable safety in patients with EGFR T790M mutation.

Liquid Biopsy for Lung Cancer: Up-to-Date and Perspectives for Screening Programs

Lung cancer is the deadliest cancer worldwide. Tissue biopsy is currently employed for the diagnosis and molecular stratification of lung cancer. Liquid biopsy is a minimally invasive approach to determine biomarkers from body fluids, such as blood, urine, sputum, and saliva. Tumor cells release cfDNA, ctDNA, exosomes, miRNAs, circRNAs, CTCs, and DNA methylated fragments, among others, which can be successfully used as biomarkers for diagnosis, prognosis, and prediction of treatment response. Predictive biomarkers are well-established for managing lung cancer, and liquid biopsy options have emerged in the last few years. Currently, detecting EGFR p.(Tyr790Met) mutation in plasma samples from lung cancer patients has been used for predicting response and monitoring tyrosine kinase inhibitors (TKi)-treated patients with lung cancer. In addition, many efforts continue to bring more sensitive technologies to improve the detection of clinically relevant biomarkers for lung cancer. Moreover, liquid biopsy can dramatically decrease the turnaround time for laboratory reports, accelerating the beginning of treatment and improving the overall survival of lung cancer patients. Herein, we summarized all available and emerging approaches of liquid biopsy-techniques, molecules, and sample type-for lung cancer.

Effects of voriconazole and fluconazole on the pharmacokinetics of almonertinib in rats by UPLC-MS/MS

Almonertinib was included in the first-line treatment of non-small cell lung cancer with EGFR T790M mutations by the Chinese Society of Clinical Oncology in 2021. Considering that immunocompromised lung cancer patients are prone to opportunistic fungal infections, and most triazole antifungal drugs are moderate or strong inhibitors of CYP3A4, this study was conducted to develop and validate an accurate and rapid ultra-performance liquid chromatography tandem mass spectrometry method for quantifying almonertinib in plasma and for investigating the pharmacokinetic changes of almonertinib caused by voriconazole and fluconazole in rats. After liquid-liquid extraction with tert-butyl methyl ether, an XSelect HSS T3 column (2.1 × 100 mm, 2.5 μm, Waters) was used for the chromatographic separation of almonertinib and sorafenib-D₃ (internal standard). The analytes were detected using an AB Sciex Triple Quad 5,500 mass spectrometer in the positive ionization mode. The method exhibited great linearity (0.5-200 ng/ml, r > 0.997) and stability under the established experimental conditions. All validation experiments were in accordance with the guidelines, and the results were all within the acceptable limits. This method was successfully applied to the researches of pharmacokinetics and drug interactions for almonertinib in rats. Voriconazole and fluconazole significantly altered the pharmacokinetic profiles of almonertinib and increased the systemic exposure of almonertinib in rats to different degrees, but further human trials should be conducted to validate the results.

FBP1 induced by β-elemene enhances the sensitivity of gefitinib in lung cancer

BACKGROUND

β-elemene is known to play a critical role in tumorigenesis as well as tyrosine kinase inhibitor (TKI) resistance in lung cancer. However, the biological function and molecular mechanism remain largely unknown.

METHODS

In this study, the common genes involved in gefitinib resistance and β-elemene were identified using bioinformatic analysis. The expression of FBP1 was examined by qRT-PCR and Western blot analysis. Cell proliferation, flow cytometry, clone formation and IC50 assays were performed to assess the effects of β-elemene and FBP1. Western blot analysis was used to evaluate apoptosis-related gene expression. Finally, in vivo experiments were conducted to assess the crucial role of FBP1 in gefitinib-resistant HCC827/GR cells in nude mice.

RESULTS

Screening analysis demonstrated that fructose-1,6-bisphosphatase (FBP1) was induced by β-elemene and downregulated in gefitinib-resistant lung cells. Functionally, overexpression of FBP1 inhibited proliferation and gefitinib resistance and promoted apoptosis of PC9/GR and HCC827/GR cells in vitro. Mechanistically, FBP1 impeded the nuclear translocation of p-STAT3. The FBP1/STAT3 axis was required for FBP1-mediated apoptosis-related gene expression. In vivo experiments further confirmed the enhanced effects of FBP1 on lung cancer cell sensitivity to gefitinib.

CONCLUSION

Our research indicated that β-elemene suppressed proliferation and enhanced sensitivity to gefitinib by inducing apoptosis through the FBP1/STAT3 axis in gefitinib-resistant lung cancer cells.

PLGA-Based Nanomedicine: History of Advancement and Development in Clinical Applications of Multiple Diseases

Research on the use of biodegradable polymers for drug delivery has been ongoing since they were first used as bioresorbable surgical devices in the 1980s. For tissue engineering and drug delivery, biodegradable polymer poly-lactic-co-glycolic acid (PLGA) has shown enormous promise among all biomaterials. PLGA are a family of FDA-approved biodegradable polymers that are physically strong and highly biocompatible and have been extensively studied as delivery vehicles of drugs, proteins, and macromolecules such as DNA and RNA. PLGA has a wide range of erosion times and mechanical properties that can be modified. Many innovative platforms have been widely studied and created for the development of methods for the controlled delivery of PLGA. In this paper, the various manufacturing processes and characteristics that impact their breakdown and drug release are explored in depth. Besides different PLGA-based nanoparticles, preclinical and clinical applications for different diseases and the PLGA platform types and their scale-up issues will be discussed.

Icotinib derivatives as tyrosine kinase inhibitors with anti-esophageal squamous carcinoma activity

Previous report showed that a variety of icotinib derivatives bearing different 1,2,3-triazole moieties, which could be readily prepared via copper (I)-catalyzed cycloaddition (CuAAC) reaction between icotinib and different azides, exhibited interesting activity against different lung cancer cell lines such as H460, H1975, H1299, A549 or PC-9. To further expand the application scope of the compounds and to validate the function of triazole groups in drug design, the anti-cancer activity of these compounds against esophageal squamous carcinoma (ESCC) cells was tested herein. Preliminary MTT experiments suggested that these compounds were active against different ESCC cell lines such as KYSE70, KYSE410, or KYSE450 as well as their drug-resistant ones. Especially, compound 3l showed interesting anticancer activity against these cell lines. The mode of action was studied via molecular docking, SPR experiments and other biochemical studies, and 3l exhibited higher binding potential to wild-type EGFR than icotinib did. In vivo anticancer study showed that 3l could inhibit tumor growth of cell-line-derived xenografts in ESCC. Study also suggested that 3l was a potent inhibitor for EGFR-TK pathway. Combining these results, 3l represents a promising lead compound for the design of anti-cancer drugs against ESCC.

Survival of Lung Cancer Patients by Histopathology in Taiwan from 2010 to 2016: A Nationwide Study

Objective: Lung cancer poses a tremendous threat to the modern world. According to Taiwan’s Ministry of Health and Welfare, lung cancer took first place in total cancer deaths in 2021. This study investigated the overall lung cancer survival based on histopathology between 2010 and 2016 in Taiwan. Method: Data from 2010 to 2016 was collected from the Taiwan Cancer Registry (TCR). The characteristics and overall survival of 71,334 lung cancer patients were analyzed according to the tumor, node, metastasis (TNM) 7th staging system. Univariate and multivariate analyses were performed to identify differences in 1-year, 3-year, and 5-year survival between different histopathologies of lung cancer. Results: The 1-year overall survival rate increased from 54.07% in 2010 to 66.14% in 2016. The 3-year overall survival rate increased from 26.57% in 2010 to 41.12% in 2016 in all patients. Among the histopathologies of lung cancer, 3-year overall survival of adenocarcinoma patients increased the most and largely contributed to the increased 3-year overall survival of all lung cancer patients. Conclusions: The introduction of target therapy has led to a tremendous increase in overall survival for lung adenocarcinoma patients. However, target therapy differs by histopathology. Choosing the right target therapy and determining the correct histopathology of lung cancer is a pivotal key in increasing the overall survival of patients. Together with immune therapy, the landscape of lung cancer treatments is changing.

Development of a Nomogram Based on 3D CT Radiomics Signature to Predict the Mutation Status of EGFR Molecular Subtypes in Lung Adenocarcinoma: A Multicenter Study

Background

This study aimed to noninvasively predict the mutation status of epidermal growth factor receptor (EGFR) molecular subtype in lung adenocarcinoma based on CT radiomics features.

Methods

In total, 728 patients with lung adenocarcinoma were included, and divided into three groups according to EGFR mutation subtypes. 1727 radiomics features were extracted from the three-dimensional images of each patient. Wilcoxon test, least absolute shrinkage and selection operator regression, and multiple logistic regression were used for feature selection. ROC curve was used to evaluate the predictive performance of the model. Nomogram was constructed by combining radiomics features and clinical risk factors. Calibration curve was used to evaluate the goodness of fit of the model. Decision curve analysis was used to evaluate the clinical applicability of the model.

Results

There were three, two, and one clinical factor and fourteen, thirteen, and four radiomics features, respectively, which were significantly related to each EGFR molecular subtype. Compared with the clinical and radiomics models, the combined model had the highest predictive performance in predicting EGFR molecular subtypes [Del-19 mutation vs. wild-type, AUC=0.838 (95% CI, 0.799-0.877); L858R mutation vs. wild-type, AUC=0.855 (95% CI, 0.817-0.894); and Del-19 mutation vs. L858R mutation, AUC=0.906 (95% CI, 0.869-0.943), respectively], and it has a stable performance in the validation set [AUC was 0.813 (95% CI, 0.740-0.886), 0.852 (95% CI, 0.790-0.913), and 0.875 (95% CI, 0.781-0.929), respectively].

Conclusion

Our combined model showed good performance in predicting EGFR molecular subtypes in patients with lung adenocarcinoma. This model can be applied to patients with lung adenocarcinoma.

Combining EGFR-TKI With SAHA Overcomes EGFR-TKI-Acquired Resistance by Reducing the Protective Autophagy in Non-Small Cell Lung Cancer

Nowadays, lung cancer has the highest mortality worldwide. The emergence of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has greatly improved the survival of patients with non-small cell lung cancer (NSCLC) having EGFR-TKI-sensitive mutations. Unfortunately, acquired resistance happens for most patients. In the present research, we found that EGFR-TKIs (such as gefitinib and osimertinib) can induce autophagy in NSCLC cell lines. Compared with parental sensitive cells, drug-resistant cells have higher autophagy activity. The use of an autophagy inhibitor could enhance the toxicity of gefitinib and osimertinib, which indicates that the enhancement of protective autophagy might be one of the mechanisms of EGFR-TKI resistance in NSCLC. In addition, increased autophagy activity is associated with decreased enhancer of zeste homolog 2 (EZH2) expression. Knockdown of EZH2 or EZH2 inhibitor treatment could lead to increased autophagy in NSCLC cells, indicating that EZH2 is a negative regulator of autophagy. We revealed that the increase in autophagy caused by the reduction of EZH2 was reversed in vitro and in vivo when combining gefitinib or osimertinib with suberoylanilide hydroxamic acid (SAHA), a broad-spectrum histone deacetylase inhibitor (HDACi). In conclusion, our results indicated that the combination of EGFR-TKIs and SAHA may be a new strategy to overcome EGFR-TKIs acquired resistance.

Targeting nicotinamide N-methyltransferase overcomes resistance to EGFR-TKI in non-small cell lung cancer cells

Activating mutations of epidermal growth factor receptor (EGFR) contributes to the progression of non-small cell lung cancer (NSCLC). EGFR tyrosine kinase inhibitor (TKI)-targeted therapy has become the standard treatment for NSCLC patients with EGFR-mutations. However, acquired resistance to these agents remains a major obstacle for managing NSCLC. Here, we investigated a novel strategy to overcome EGFR TKI resistance by targeting the nicotinamide N-methyltransferase (NNMT). Using iTRAQ-based quantitative proteomics analysis, we identified that NNMT was significantly increased in EGFR-TKI-resistant NSCLC cells. Moreover, we found that NNMT expression was increased in EGFR-TKI-resistant NSCLC tissue samples, and higher levels were correlated with shorter progression-free survival in EGFR-TKI-treated NSCLC patients. Knockdown of NNMT rendered EGFR-TKI-resistant cells more sensitive to EGFR-TKI, whereas overexpression of NNMT in EGFR-TKI-sensitive cells resulted in EGFR-TKI resistance. Mechanically, upregulation of NNMT increased c-myc expression via SIRT1-mediated c-myc deacetylation, which in turn promoted glycolysis and EGFR-TKI resistance. Furthermore, we demonstrated that the combination of NNMT inhibitor and EGFR-TKI strikingly suppressed the growth of EGFR-TKI-resistant NSCLC cells both in vitro and in vivo. In conclusion, our research indicated that NNMT overexpression is important for acquired resistance to EGFR-TKI and that targeting NNMT might be a potential therapeutic strategy to overcome resistance to EGFR TKI.

CWHM-1008 Induces Apoptosis and Protective Autophagy through the Akt/mTOR Axis in LUAD Cells

Recent studies have revealed that antiparasitic agents showed promising inhibitory effects on tumors, raising a possibility that repositioning this class of drugs may shed new light on clinical therapy against tumors. CWHM-1008 is a novel class of antimalarial drug; however, the inhibitory impact of CWHM-1008 on lung adenocarcinoma (LUAD) cells remains unclear. This study aimed to explore the anticancer effect and underlying mechanisms of CWHM-1008 on LUAD cells in vitro and in vivo. Human LUAD cells, H358 and A549, were treated with varying concentrations of CWHM-1008 at different lengths of time. Cell viability, colony formation, cell count, flow cytometry findings, microtubule-associated protein-1 light chain 3-green- (LC3-) GFP/RFP adenovirus infection status, and the expression of apoptosis and autophagy-related proteins were examined. Potential effects of an autophagy inhibitor (LY294002) and constitutively active Akt plasmid (CA-Akt) on CWHM-1008-induced apoptosis were also examined. Our results showed that CWHM-1008 significantly inhibited proliferation, induced apoptosis, and enhanced autophagy flux by blocking the RAC-alpha serine/threonine-protein kinase/the mammalian target of rapamycin (Akt/mTOR) axis in two LUAD cells. In addition, autophagy inhibited by LY294002 or CA-Akt transfection accelerated CWHM-1008-induced apoptosis in those LUAD cells. Moreover, CWHM-1008 significantly inhibited the growth and induced apoptosis of A549 cell in nude mice in vivo. The present findings provide new insights into anticancer properties of CWHM-1008, suggesting that it may be an adjuvant treatment for LUAD treatment, warranting further study.

A New Series of Indeno[1,2-c]pyrazoles as EGFR TK Inhibitors for NSCLC Therapy

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death throughout the world. Due to the shortcomings of traditional chemotherapy, targeted therapies have come into prominence for the management of NSCLC. In particular, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) therapy has emerged as a first-line therapy for NSCLC patients with EGFR-activating mutations. In this context, new indenopyrazoles, which were prepared by an efficient microwave-assisted method, were subjected to in silico and in vitro assays to evaluate their potency as EGFR TK-targeted anti-NSCLC agents. Compound 4 was the most promising antitumor agent towards A549 human lung adenocarcinoma cells, with an IC₅₀ value of 6.13 µM compared to erlotinib (IC₅₀ = 19.67 µM). Based on its low cytotoxicity to peripheral blood mononuclear cells (PBMCs), it can be concluded that compound 4 exerts selective antitumor action. This compound also inhibited EGFR TK with an IC₅₀ value of 17.58 µM compared to erlotinib (IC₅₀ = 0.04 µM) and induced apoptosis (56.30%). Taking into account in silico and in vitro data, compound 4 stands out as a potential EGFR TKI for the treatment of NSCLC.

ECE2 is a prognostic biomarker associated with m6A modification and involved in immune infiltration of lung adenocarcinoma

BACKGROUND

The targeted therapy for lung cancer relies on prognostic genes and requires further research. No research has been conducted to determine the effect of endothelin-converting enzyme 2 (ECE2) in lung cancer.

METHODS

We analyzed the expression of ECE2 in lung adenocarcinoma (LUAD) and normal adjacent tissues and its relationship with clinicopathological characteristics from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus database (GEO). Immunohistochemical staining was used to further validate the findings. GO/KEGG enrichment analysis and gene set enrichment analysis (GSEA) of ECE2 co-expression were performed using R software. Data from TIMER, the GEPIA database, and TCGA were analyzed to determine the relationship between ECE2 expression and LUAD immune infiltration. To investigate the relationship between ECE2 expression levels and LUAD m6A modification, TCGA data and GEO data were analyzed.

RESULTS

ECE2 is highly expressed in various cancers including LUAD. ECE2 showed high accuracy in distinguishing tumor and normal sample results. The expression level of ECE2 in LUAD was significantly correlated with tumor stage and prognosis. GO/KEGG enrichment analysis showed that ECE2 was closely related to mitochondrial gene expression, ATPase activity and cell cycle. GSEA analysis showed that ECE2-related differential gene enrichment pathways were related to mitotic cell cycle, MYC pathway, PLK1 pathway, DNA methylation pathway, HIF1A pathway and Oxidative stress-induced cellular senescence. Analysis of the TIMER, GEPIA database, and TCGA datasets showed that ECE2 expression levels were significantly negatively correlated with B cells, CD4+ cells, M2 macrophages, neutrophils, and dendritic cells. TCGA and GEO datasets showed that ECE2 was significantly associated with m6A modification-related genes HNRNPC, IGF2BP1, IGF2BP3 and RBM1.

CONCLUSION

ECE2 is associated with m6A modification and immune infiltration and is a prognostic biomarker in LUAD.

Circ_SETD3 regulates gefitinib sensitivity and tumor progression by miR-873-5p-dependent regulation of APPBP2 in non-small cell lung cancer

Previous data have shown the prominent clinical efficacy of gefitinib in non-small cell lung cancer (NSCLC) patients. However, its therapeutic efficacy is limited because of the development of gefitinib resistance. This research is designed to investigate the role of circRNA SET domain containing 3, actin histidine (circ_SETD3) in the sensitivity of NSCLC to gefitinib. The expression of circ_SETD3, microRNA-873-5p (miR-873-5p) and amyloid protein-binding protein 2 (APPBP2) was detected by qRT-PCR. Protein expression was determined by western blot analysis or immunohistochemistry assay. The half-maximal inhibitory concentration of gefitinib was determined by 3-(4,5-Dimethylthazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell proliferation was investigated by 5-Ethynyl-29-deoxyuridine (EdU), cell colony formation and MTT assays. Cell apoptosis was analyzed by Annexin V-fluorescein isothiocyanate and propidium iodide double staining assay. Transwell assay was employed to evaluate cell migration and invasion. Additionally, the binding relationship between miR-873-5p and circ_SETD3 or APPBP2 was predicted by starbase online database, and identified by a dual-luciferase reporter assay. Further, circ_SETD3 silencing-mediated effect on tumor sensitivity to gefitinib in vivo was confirmed by xenograft mouse model experiment. Circ_SETD3 and APPBP2 expression were upregulated, while miR-873-5p was downregulated in gefitinib-resistant NSCLC tissues and cells compared with gefitinib-sensitive NSCLC tissues or cells. Reduced expression of circ_SETD3 repressed gefitinib resistance, proliferation, migration and invasion, but induced apoptosis of gefitinib-resistant NSCLC cells. Additionally, circ_SETD3 modulated gefitinib sensitivity and tumor development by binding to miR-873-5p. APPBP2 upregulation attenuated miR-873-5p-mediated gefitinib sensitivity and NSCLC progression. Furthermore, circ_SETD3 absence improved tumor sensitivity to gefitinib in vivo. Circ_SETD3 knockdown improved gefitinib sensitivity and repressed NSCLC cell malignancy via miR-873-5p/APPBP2 axis, which provides a theoretical basis for using circ_SETD3-based therapeutic strategies to improve NSCLC sensitivity to gefitinib.

Synthesis and preliminary structure-activity relationship study of 3-methylquinazolinone derivatives as EGFR inhibitors with enhanced antiproliferative activities against tumour cells

In this paper, a set of 3-methylquniazolinone derivatives were designed, synthesised, and studied the preliminary structure-activity relationship for antiproliferative activities. All target compounds performed significantly inhibitory effects against wild type epidermal growth factor receptor tyrosine kinase (EGFRwt-TK) and tumour cells (A431, A549, MCF-7, and NCI-H1975). In particular, compound 4d 3-fluoro-N-(4-((3-methyl-4-oxo-3,4-dihydroquinazolin-2-yl)methoxy)phenyl)benzamide showed higher antiproliferative activities against all tumour cells than Gefitinib (IC50 of 3.48, 2.55, 0.87 and 6.42 μM, respectively). Furthermore, compound 4d could induce apoptosis of MCF-7 cells and arrest in G2/M phase at the tested concentration. Molecular docking and ADMET studies showed that compound 4d could closely form many hydrogen bonds with EGFRwt-TK. Therefore, compound 4d is potential to develop as novel anti-cancer drug.

Drug resistance of targeted therapy for advanced non-small cell lung cancer harbored EGFR mutation: from mechanism analysis to clinical strategy

PURPOSE

Non-small cell lung cancer (NSCLC) accounts for about 85% in all cases of lung cancer. In recent years, molecular targeting drugs for NSCLC have been developed rapidly. The epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have changed the paradigm of cancer therapy from empirical cytotoxic chemotherapy to molecular-targeted cancer therapy. Currently, there are three generations of EGFR-TKIs, all of which have achieved good efficacy in clinical therapy. However, most patients developed drug resistance after 6-13 months EGFR-TKIs treatment. Therefore, a comprehensive understanding of EGFR-TKIs resistance mechanisms is of vital importance for clinical management of NSCLC.

METHODS

Relevant data and information about the topic were obtained by searching PubMed (Medline), Web of Science and Google Scholar using the subject headings, such as "NSCLC", "EGFR-TKIs resistance", "EGFR mutations", "human epidermal growth factor receptor-2 (HER2/erbB-2)", "hepatocyte growth factor (HGF)", "vascular endothelial growth factor (VEGF)", "insulin-like growth factor 1 (IGF-1)", "epithelial-mesenchymal transition (EMT)", "phosphatase and tensin homolog (PTEN)", "RAS mutation", "BRAF mutation", "signal transducer and activator of transcription 3 (STAT3)", and "tumor microenvironment", etc. RESULTS: The mechanisms for EGFR-TKIs resistance include EGFR mutations, upregulation of HER2, HGF/c-MET, VEGF IGF1, EMT and STAT3 pathways, mutations of PTEN, RAS and BRAF genes, and activation of other by-pass pathways. These mechanisms are interconnected and can be potential targets for the treatment of NSCLC.

CONCLUSION

In this review, we discuss the mechanisms of EGFR-TKIs drug resistance and the clinical strategies to overcome drug resistance from the perspective of EGFR-TKIs combined treatment.

MiR-873-5p: A Potential Molecular Marker for Cancer Diagnosis and Prognosis

miR-873 is a microRNA located on chromosome 9p21.1. miR-873-5p and miR-873-3p are the two main members of the miR-873 family. Most studies focus on miR-873-5p, and there are a few studies on miR-873-3p. The expression level of miR-873-5p was down-regulated in 14 cancers and up-regulated in 4 cancers. miR-873-5p has many targeted genes, which have unique molecular functions such as catalytic activity, transcription regulation, and binding. miR-873-5p affects cancer development through the PIK3/AKT/mTOR, Wnt/β-Catenin, NF-κβ, and MEK/ERK signaling pathways. In addition, the target genes of miR-873-5p are closely related to the proliferation, apoptosis, migration, invasion, cell cycle, cell stemness, and glycolysis of cancer cells. The target genes of miR-873-5p are also related to the efficacy of several anti-cancer drugs. Currently, in cancer, the expression of miR-873-5p is regulated by a variety of epigenetic factors. This review summarizes the role and mechanism of miR-873-5p in human tumors shows the potential value of miR-873-5p as a molecular marker for cancer diagnosis and prognosis.

Radiomic Feature-Based Nomogram: A Novel Technique to Predict EGFR-Activating Mutations for EGFR Tyrosin Kinase Inhibitor Therapy

Objectives

To develop and validate a radiomic feature-based nomogram for preoperative discriminating the epidermal growth factor receptor (EGFR) activating mutation from wild-type EGFR in non-small cell lung cancer (NSCLC) patients.

Material

A group of 301 NSCLC patients were retrospectively reviewed. The EGFR mutation status was determined by ARMS PCR analysis. All patients underwent nonenhanced CT before surgery. Radiomic features were extracted (GE healthcare). The maximum relevance minimum redundancy (mRMR) and LASSO, were used to select features. We incorporated the independent clinical features into the radiomic feature model and formed a joint model (i.e., the radiomic feature-based nomogram). The performance of the joint model was compared with that of the other two models.

Results

In total, 396 radiomic features were extracted. A radiomic signature model comprising 9 selected features was established for discriminating patients with EGFR-activating mutations from wild-type EGFR. The radiomic score (Radscore) in the two groups was significantly different between patients with wild-type EGFR and EGFR-activating mutations (training cohort: P<0.0001; validation cohort: P=0.0061). Five clinical features were retained and contributed as the clinical feature model. Compared to the radiomic feature model alone, the nomogram incorporating the clinical features and Radscore exhibited improved sensitivity and discrimination for predicting EGFR-activating mutations (sensitivity: training cohort: 0.84, validation cohort: 0.76; AUC: training cohort: 0.81, validation cohort: 0.75). Decision curve analysis demonstrated that the nomogram was clinically useful and surpassed traditional clinical and radiomic features.

Conclusions

The joint model showed favorable performance in the individualized, noninvasive prediction of EGFR-activating mutations in NSCLC patients.

TPD7 inhibits the non-small cell lung cancer HCC827 cell growth by regulating EGFR signalling pathway

Non-small cell lung cancer (NSCLC) accounts for 85% of lung cancer cases, and is characterized by more insensitivity to chemotherapy and poor prognosis. Epidermal growth factor receptor (EGFR) has been confirmed as a tumorigenic driving factor of NSCLC. Taspine has been proved effective in the inhibition of malignant tumours. Here, we found TPD7, a novel taspine derivative, exerted most inhibitory effect on EGFR-dependent HCC827 cells and investigated the underling mechanism. In addition, TPD7 could block cell cycle at G0/G1 phase of HCC827 cells by regulating the expression of cyclin D1 and cyclin E. Furthermore, TPD7 induced HCC827 cell apoptosis by regulating the expression of BCL-2 family proteins. Further study revealed that TPD7 could down-regulate the phosphorylation of EGFR and downstream members. TPD7 might present a potential EGFR inhibitor in the treatment of NSCLC.

Overcoming anti-cancer drug resistance via restoration of tumor suppressor gene function

The cytotoxic anti-cancer drugs cisplatin, paclitaxel, doxorubicin, 5-fluorouracil (5-FU), as well as targeted drugs including imatinib, erlotinib, and nivolumab, play key roles in clinical cancer treatment. However, the frequent emergence of drug resistance severely comprosises their anti-cancer efficacy. A number of studies indicated that loss of function of tumor suppressor genes (TSGs) is involved in the development of cancer drug resistance, apart from decreased drug influx, increased drug efflux, induction of anti-apoptosis mechanisms, alterations in tumor microenvironment, drug compartmentalization, enhanced DNA repair and drug inactivation. TSGs are involved in the pathogenesis of tumor formation through regulation of DNA damage repair, cell apoptosis, autophagy, proliferation, cell cycle progression, and signal transduction. Our increased understanding of TSGs in the past decades demonstrates that gene mutation is not the only reason that leads to the inactivation of TSGs. Loss of function of TSGs may be based on the ubiquitin-proteasome pathway, epigenetic and transcriptional regualtion, post-translation modifications like phosphorylation as well as cellular translocation of TSGs. As the above processes can constitute"druggable targets", these mechanisms provide novel therapeutic approaches in targeting TSGs. Some small molecule compounds targeting these approaches re-activated TSGs and reversed cancer drug resistance. Along this vein, functional restoration of TSGs is a novel and promising approach to surmount cancer drug resistance. In the current review, we draw a scenario based on the role of loss of function of TSGs in drug resistance, on mechanisms leading to inactivation of TSGs and on pharmacological agents acting on these mechanisms to overcome cancer drug resistance. This review discusses novel therapeutic strategies targeting TSGs and offers possible modalities to conquer cancer drug resistance.

EML4-ALK-mediated activation of the JAK2-STAT pathway is critical for non-small cell lung cancer transformation

BACKGROUND

The echinoderm microtubule-associated protein-like-4 anaplastic lymphoma kinase (EML4-ALK) fusion gene was identified in a subset of non-small cell lung cancer (NSCLC) patients. They responded positively to ALK inhibitors. This study aimed to characterize the mechanisms triggered by EML4-ALK to induce NSCLC transformation.

METHODS

HEK293 and NIH3T3 cells were transfected with EML4-ALK variant 3 or pcDNA3.1-NC. H2228 cells were transfected with siRNA-EML4-ALK or siRNA-NC. Cell viability and proliferation were measured by the CCK-8 and EdU methods, respectively. Flow cytometry revealed apoptosis. Gene expression profiles were generated from a signaling pathway screen in EML4-ALK-regulated lung cancer cells and verified by qPCR and Western blotting. The co-immunoprecipitation and immunohistochemistry/ immunofluorescence determined the interaction and colocalization of JAK2-STAT pathway components with EML4-ALK.

RESULTS

Microarray identified several genes involved in the JAK2-STAT pathway. JAK2 and STAT6 were constitutively phosphorylated in H2228 cells. EML4-ALK silencing downregulated phosphorylation of STAT6. Expression of EML4-ALK in HEK293 and NIH3T3 cells activated JAK2, STAT1, STAT3, STAT5, and STAT6. In EML4-ALK-transfected HEK293 cells and EML4-ALK-positive H2228 cells, activated STAT6 and JAK2 colocalized with ALK. STAT3 and STAT6 were phosphorylated and translocated to the nucleus of H2228 cells following IL4 or IL6 treatment. Apoptosis increased, while cell proliferation and DNA replication decreased in H2228 cells following EML4-ALK knockdown. In contrast, HEK293 cell viability increased following EML4-ALK overexpression, while H2228 cell viability significantly decreased after treatment with ALK or JAK-STAT pathway inhibitors.

CONCLUSIONS

Our data suggest that the aberrant expression of EML4-ALK leads to JAK2-STAT signaling pathway activation, which is essential for the development of non-small cell lung cancer.

SH-1028, An Irreversible Third-Generation EGFR TKI, Overcomes T790M-Mediated Resistance in Non-Small Cell Lung Cancer

SH-1028 is an irreversible third-generation EGFR TKI. Both SH-1028 and osimertinib have a pyrimidine structure (a typical mutant-selective EGFR TKI structure). Compared with osimertinib, SH-1028 is modified on the indole ring, thus resulting in a more stable 6,7,8,9-tetrahydro-pyrrolo [1, 2-a] indol structure. In this study, we explored the anti-tumor effect of SH-1028 in vitro and in vivo, the inhibition of cell signal, such as EGFR and ERK phosphorylation, and verified the relationship between the pharmacokinetics and pharmacodynamic responses. Firstly, SH-1028 selectively inhibited EGFR sensitive and resistant mutations, with up to 198-fold more effective compared with wild-type EGFR cells. Then, in mouse xenograft models, oral administration of SH-1028 at a daily dose of 5 mg/kg significantly inhibited proliferation of tumor cells with EGFR sensitive mutation (exon 19 del) and resistant mutation (T790 M) for consecutive 14 days, with no TKI-induced weight loss. Moreover, SH-1028 exhibited good bioavailability, and was distributed extensively from the plasma to the tissues. The main metabolite of SH-1028, Imp3, was tested and showed no wild-type EGFR inhibition or off-target effects. In conclusion, SH-1028 is a new third-generation EGFR inhibitor that exhibits potent activity against EGFR sensitive and resistant (T790 M) mutations.

Enhancing the Therapeutic Efficacy of Gefitinib in Human Non-Small-Cell Lung Cancer through Drug Combination

The interaction between tumor cells and the tumor microenvironment (TME) significantly influences tumorigenesis, so TME-targeted therapy has attracted widespread attention. We have previously demonstrated that the combination of dipyridamole, bestatin, and dexamethasone (DBD mix, DBDx) is effective against heterogeneous human pancreatic cancer and hepatocellular carcinoma in mouse xenograft models. To further expand the therapeutic potential of this drug combination, herein, we investigated the antitumor efficacy and the underlying mechanism of DBDx and the combination of DBDx and gefitinib in different mouse xenograft models of human non-small-cell lung cancer (NSCLC). Three human cancer cell lines H460, PG, and A431 were used to determine the apoptosis and growth inhibition induced by DBDx, gefitinib, and their combinations. Changes in epidermal growth factor receptor (EGFR) signaling pathway-related proteins were analyzed following treatment using western blotting. In vitro, DBDx strongly inhibited the proliferation of tumor cells, whereas the combined treatment exhibited a significant synergistic effect. Compared with DBDx, the combination treatment further induced apoptosis and downregulated the expression of molecules associated with EGFR signaling pathway. In vivo, compared with DBDx alone, the combination treatment distinctly inhibited tumor growth in mouse xenograft models of human NSCLC. Overall, our results indicate that the combination of DBDx and gefitinib in the treatment of human NSCLC is very promising, which warrants further translational studies.

Concurrent use of metformin enhances the efficacy of EGFR-TKIs in patients with advanced EGFR-mutant non-small cell lung cancer-an option for overcoming EGFR-TKI resistance

Background

Resistance is almost inevitable and is still a major obstacle in epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy. Only limited relevant clinical studies evaluated the therapeutic effects by combing metformin and EGFR-TKIs in non-small cell lung cancer (NSCLC) patients. Therefore, we evaluated the efficacy of concurrent use of metformin with EGFR-TKIs, and assessed whether the addition of metformin may improve clinical outcomes and delay the occurrence of EGFR-TKI resistance.

Methods

We conducted cell proliferation and apoptosis assay for investigation of metformin in combination with EGFR-TKIs to overcome EGFR-TKI resistance in vitro. Furthermore, we retrospectively reviewed clinicopathological characteristics and therapeutic outcomes of EGFR-mutant advanced NSCLC diabetic patients who received EGFR-TKIs with or without concurrent use of metformin.

Results

In vitro experiment, metformin showed synergistic interaction both with gefitinib in PC9R (CI =0.77) and with osimertinib in PC9R/OR (CI =0.77) in proliferation inhibition assay. Metformin can also augment apoptosis effect of these TKI-resistant cells to EGFR-TKIs. In retrospective cohort, a total of 85 patients were identified (cohort A), in which 28 patients had concurrent use of metformin. The objective response rate in metformin use group was significantly higher (85.7% vs. 47.4%, P=0.001). The median progression-free survival (PFS) and overall survival (OS) in metformin use group were significantly longer (21.6 vs. 9.2 months, P=0.000; 48.4 vs. 36.6 months, P=0.049). Further analysis revealed that metformin obviously prolonged the median PFS2 of osimertinib treatment among patients who progressed to prior line EGFR-TKIs due to secondary EGFR T790M mutation (cohort B).

Conclusions

Our study suggest that concurrent use of metformin could be beneficial to EGFR-mutant NSCLC patients treated with either first-line EGFR-TKIs or second-line osimertinib.

Blocking Aerobic Glycolysis by Targeting Pyruvate Dehydrogenase Kinase in Combination with EGFR TKI and Ionizing Radiation Increases Therapeutic Effect in Non-Small Cell Lung Cancer Cells

Simple Summary

Non-small cell lung cancer (NSCLC) patients harboring oncogenic mutations in the epidermal growth factor receptor (EGFR) inevitably develop resistance to targeted EGFR tyrosine kinase inhibitors (TKI) therapy. To support malignant features associated with cancer development and therapy resistance, the cancer cells adapt their metabolic rate and pathways. As an example, aerobic glycolysis, where the cells use glycolysis in the presence of oxygen, is frequently seen. Here we show that targeting aerobic glycolysis represents a promising strategy in cancer therapeutics.

Abstract

Increased glycolytic activity is a hallmark of cancer initiation and progression and is often observed in non-small cell lung cancer (NSCLC). Pyruvate dehydrogenase (PDH) complex acts as a gatekeeper between glycolysis and oxidative phosphorylation, and activation of PDH is known to inhibit glycolytic activity. As part of a standard therapeutic regimen, patients with NSCLC harboring oncogenic mutations in the epidermal growth factor receptor (EGFR) are treated with EGFR tyrosine kinase inhibitors (EGFR TKIs). Independent of good initial response, development of resistance to this therapy is inevitable. In the presented work, we propose that inhibition of glycolysis will add to the therapeutic effects and possibly prevent development of resistance against both EGFR TKIs and ionizing radiation in NSCLC. Analysis of transcriptome data from two independent NSCLC patient cohorts identified increased expression of pyruvate dehydrogenase kinase 1 (PDHK1) as well as upregulated expression of genes involved in glucose metabolism in tumors compared to normal tissue. We established in vitro models of development of resistance to EGFR TKIs to study metabolism and determine if targeting PDHK would prevent development of resistance to EGFR TKIs in NSCLC cells. The PDHK1 inhibitor dichloroacetate (DCA) in combination with EGFR TKIs and/or ionizing radiation was shown to increase the therapeutic effect in our NSCLC cell models. This mechanism was associated with redirected metabolism towards pyruvate oxidation and reduced lactate production, both in EGFR TKI sensitive and resistant NSCLC cells. Using DCA, the intracellular pool of pyruvate available for lactic fermentation becomes limited. Consequently, pyruvate is redirected to the mitochondria, and reinforces mitochondrial activity. Addition of DCA to cell culture deacidifies the extracellular microenvironment as less lactate is produced and excreted. In our study, we find that this redirection of metabolism adds to the therapeutic effect of EGFR TKI and ionizing radiation in NSCLC.

Akt kinase LANCL2 functions as a key driver in EGFR-mutant lung adenocarcinoma tumorigenesis

Epidermal growth factor receptor (EGFR) is a key oncogene in lung adenocarcinoma (LUAD). Resistance to EGFR tyrosine kinase inhibitors is a major obstacle for EGFR-mutant LUAD patients. Our gene chip array, quantitative polymerase chain reaction validation, and shRNA-based high-content screening identified the Akt kinase lanthionine synthetase C-like protein 2 (LANCL2) as a pro-proliferative gene in the EGFR-mutant LUAD cell line PC9. Therefore, we investigated whether LANCL2 plays a role in promoting cell proliferation and drug resistance in EGFR-mutant LUAD. In silico clinical correlation analysis using the Cancer Genome Atlas Lung Adenocarcinoma dataset revealed a positive correlation between LANCL2 and EGFR expression and an inverse relationship between LANCL2 gain-of-function and survival in LUAD patients. The EGFR-mutant LUAD cell lines PC9 and HCC827 displayed higher LANCL2 expression than the non-EGFR-mutant cell line A549. In addition, LANCL2 was downregulated following gefitinib+pemetrexed combination therapy in PC9 cells. LANCL2 knockdown reduced proliferation and enhanced apoptosis in PC9, HCC827, and A549 cells in vitro and suppressed murine PC9 xenograft tumor growth in vivo. Notably, LANCL2 overexpression rescued these effects and promoted gefitinib + pemetrexed resistance in PC9 and HCC827 cells. Pathway analysis and co-immunoprecipitation followed by mass spectrometry of differentially-expressed genes in LANCL2 knockdown cells revealed enrichment of several cancer signaling pathways. In addition, Filamin A and glutathione S-transferase Mu 3 were identified as two novel protein interactors of LANCL2. In conclusion, LANCL2 promotes tumorigenic proliferation, suppresses apoptosis, and promotes gefitinib+pemetrexed resistance in EGFR-mutant LUAD cells. Based on the positive association between LANCL2, EGFR, and downstream Akt signaling, LANCL2 may be a promising new therapeutic target for EGFR-mutant LUAD.

Exosomal Delivery of FTO Confers Gefitinib Resistance to Recipient Cells through ABCC10 Regulation in an m6A-dependent Manner

Gefitinib is suitable for the treatment of locally advanced or metastatic non-small cell lung cancer. However, the development of acquired resistance limits its long-term efficacy in regardless of significant clinical benefit to patients. Therefore, to elucidate the mechanism of gefitinib resistance in addition to target gene mutation may greatly increase its clinical efficacy. It was found first that N ⁶-methyladenosine RNA demethylase FTO was significantly enriched in serum exosomes of gefitinib-resistant (GR) patients compared with that of gefitinib-sensitive (GS) patients through exosomal RNA sequencing. Meanwhile, the average m⁶A proportion in GR patients was significantly lower when compared with that in GS patients. Besides, GR cell-derived exosome internalization attenuated the total m⁶A abundance and gefitinib sensitivity of PC9 cells. Not only FTO knockdown enhanced the gefitinib sensitivity of GR cells but also FTO reduction in donor exosomes alleviated the acquired resistance of recipient PC9 cells. GR cell-derived exosomal-FTO promoted ABCC10 of recipient cells in a m⁶A-dependent manner. FTO/YTHDF2/ABCC10 axis played a role in intercellular transmission of GR cell-derived exosome-mediated gefitinib resistance both in vitro and in vivo. In general, this research showed that m⁶A modification was involved in the decrease of gefitinib sensitivity. GR cell-derived exosomes could decrease gefitinib sensitivity of recipient cells in exosomal delivery of FTO-dependent manner. FTO/YTHDF2/ABCC10 axis played a role in intercellular transmission of GR cell-derived exosome-mediated gefitinib resistance. IMPLICATIONS: Our results elucidated another potential molecular mechanism of gefitinib resistance in non-small cell lung cancer besides secondary EGFR mutations.

Recent advances of dual FGFR inhibitors as a novel therapy for cancer

Fibroblast growth factor receptor (FGFR) includes four highly conserved transmembrane receptor tyrosine kinases (FGFR1-4). FGF and FGFR regulate many biological processes, such as angiogenesis, wound healing and tissue regeneration. The abnormal expression of FGFR is related to the tumorigenesis, tumor progression and drug resistance of anti-tumor treatments in many types of tumors. Nowadays there are many anti-cancer drugs targeting FGFR. However, traditional single-target anti-tumor drugs are easy to acquire drug resistance. The therapeutic effect can be enhanced by simultaneously inhibiting FGFR and another target (such as VEGFR, EGFR, PI3K, CSF-1R, etc.). We know drug combination can bring problems such as drug interactions. Therefore, the development of FGFR dual target inhibitors is an important direction. In this paper, we reviewed the research on dual FGFR inhibitors in recent years and made brief comments on them.

Downregulation of breast cancer resistance protein by long-term fractionated radiotherapy sensitizes lung adenocarcinoma to SN-38

Chemotherapy is usually the subsequent treatment for non-small cell lung cancer patients with acquired radioresistance after long-term fractionated radiotherapy. However, few studies have focused on the selection of chemotherapeutic drugs to treat lung adenocarcinoma patients with radioresistance. Our study compared the sensitivity changes of lung adenocarcinoma cells to conventional chemotherapeutic drugs under radioresistant circumstances by using three lung adenocarcinoma cell models, which were irradiated with fractionated X-rays at a total dose of 60 Gy. The results showed that the toxicities of paclitaxel, docetaxel and SN-38 were increased in radioresistant cells. The IC₅₀ values of docetaxel and SN-38 decreased 0 ~ 3 times and 3 ~ 36 times in radioresistant cells, respectively. Notably, the A549 radioresistant cells were approximately 36 times more sensitive to SN-38 than the parental cells. Further results revealed that the downregulation of the efflux transporter BCRP by long-term fractionated irradiation was an important factor contributing to the increased cytotoxicity of SN-38. In addition, the reported miRNAs and transcriptional factors that regulate BCRP did not participate in the downregulation. In conclusion, these results presented important data on the sensitivity changes of lung adenocarcinoma cells to chemotherapeutic drugs after acquiring radioresistance and suggested that irinotecan (the prodrug of SN-38) might be a promising drug candidate for lung adenocarcinoma patients with acquired radioresistance.

[Advances and Challenges of Local Thermal Ablation in Non-small Cell Lung Cancer]

非小细胞肺癌（non-small cell lung cancer, NSCLC）是原发性肺癌的主要类型，手术切除、放化疗、靶向治疗及免疫治疗等是其主要的治疗模式。近年来，热消融在各期NSCLC的临床应用中受到越来越多的关注。热消融作为一种安全、高效的局部治疗手段，合理的临床应用可以给NSCLC患者带来更多的临床获益。然而其在NSCLC中的应用仍然存在许多尚待研究探讨的问题。本文对近年来热消融在NSCLC中的应用现状作以综述，旨在探讨目前存在的争议问题和未来研究方向。

Real-world use of osimertinib for epidermal growth factor receptor T790M-positive non-small cell lung cancer in Japan

Objective

Adverse drug reactions (ADRs) during real-world osimertinib use were investigated in Japan.

Methods

Patients with epidermal growth factor receptor (EGFR) T790M-positive non-small cell lung cancer treated with second-line or later oral osimertinib per the Japanese package insert (80 mg once daily) were included. Data were collected between 28 March 2016 and 31 August 2018.

Results

The median observation period in the safety analysis population (n = 3578) was 343.0 days. ADRs (defined as adverse events whose causality to osimertinib could not be denied by the attending physicians or manufacturer) were reported in 58.1% (2079/3578) of patients. ADRs of interstitial lung disease events were reported in 6.8% (245/3578; Grade ≥ 3, 2.9% [104/3578]) of patients, of whom 29 (11.8%) died (0.8% of patients overall). ADRs of QT interval prolonged, liver disorder and haematotoxicity were reported in 1.3% (45/3578; Grade ≥ 3, 0.1% [5/3578]), 5.9% (212/3578; Grade ≥ 3, 1.0% [35/3578]) and 11.4% (409/3578; Grade ≥ 3, 2.9% [104/3578]) of patients, respectively. In the efficacy analysis population (n = 3563), 119 (3.3%) patients had complete responses, 2373 (66.6%) had partial responses and 598 (16.8%) had stable disease. The objective response rate was 69.9%; disease control rate was 86.7%; and median progression-free survival (PFS) was 12.3 months. At 6 and 12 months, PFS rates were 77.4% (95% confidence interval [CI], 75.9–78.9) and 53.2% (95% CI, 51.3–55.1) and overall survival rates were 88.3% (95% CI, 87.2–89.4) and 75.4% (95% CI, 73.8–77.0), respectively.

Conclusions

These data support the currently established benefit-risk assessment of osimertinib in this patient population.

Real-World Evaluation of Factors for Interstitial Lung Disease Incidence and Radiologic Characteristics in Patients With EGFR T790M-positive NSCLC Treated With Osimertinib in Japan

INTRODUCTION

Using real-world Japanese postmarketing data, we characterized interstitial lung disease (ILD) development during the second- or later-line osimertinib treatment for EGFR mutation-positive NSCLC. Retrospective radiologic image evaluation of patients developing ILD was also performed.

METHODS

Patients who had ILD events reported as an adverse drug reaction by their physicians and who were assessed as having developed ILD as assessed by an ILD expert committee in Japan were included.

RESULTS

Among 3578 patients, 252 ILD events were reported in 245 patients (6.8%) by their attending physicians. The median (range) time to the first onset of ILD after osimertinib treatment initiation was 63.0 (5-410) days, and 29 patients with a fatal outcome were reported. The ILD expert committee assessed 231 of 3578 patients (6.5%) as having ILD. A previous history of nivolumab therapy (adjusted OR: 2.84; 95% confidence interval: 1.98-4.07) and a history or concurrence of ILD (3.51; 2.10-5.87) were identified as factors potentially associated with ILD onset during osimertinib treatment. In patients who had received a previous nivolumab treatment, the number and proportion of patients developing ILD were highest for patients who discontinued nivolumab treatment within the first month before initiating osimertinib; trends for decreasing incidence and proportion were observed, with an increasing duration between the end of nivolumab treatment and the initiation of osimertinib treatment.

CONCLUSIONS

The frequency of ILD was consistent with the known osimertinib safety profile in the Japanese population. A history or concurrence of ILD and history of previous nivolumab therapy are factors potentially associated with ILD onset during osimertinib treatment.

Metformin Overcomes Acquired Resistance to EGFR TKIs in EGFR-Mutant Lung Cancer via AMPK/ERK/NF-κB Signaling Pathway

Background: The major limitation of EGFR TKIs in EGFR-mutant lung cancer therapy is the development of acquired resistance. The underlying mechanisms remain unknown in about 30% of cases. NF-κB activation was encountered in the acquired resistance to EGFR TKIs. Unfortunately, none of NF-κB inhibitors has been clinically approved. The most commonly used antidiabetic drug metformin has demonstrated antitumor effects associated with NF-κB inhibition. Therefore, in this study, metformin was examined for its antitumor and antiresistance effects and underlying mechanisms.

Methods:In vitro and in vivo EGFR-mutant lung cancer models with acquired resistance to EGFR TKIs were used.

Results: We found that NF-κB was activated in EGFR-mutant lung cancer cells with acquired resistance to EGFR TKIs. Metformin inhibited proliferation and promoted apoptosis of lung cancer cells, especially those with acquired EGFR TKI resistance. Moreover, metformin reversed and delayed acquired resistance to EGFR TKIs as well as suppressed cancer stemness in EGFR-mutant lung cancer. Mechanistically, those effects of metformin were associated with activation of AMPK, resulting in the inhibition of downstream ERK/NF-κB signaling.

Conclusions: Our data provided novel and further molecular rationale and preclinical data to support combination of metformin with EGFR TKIs to treat EGFR-mutant lung cancer patients, especially those with acquired resistance.

LncRNA RMRP Promotes Cell Proliferation and Invasion Through miR-613/NFAT5 Axis in Non-Small Cell Lung Cancer

Background

The abnormal expression of RMRP and miR-613 was respectively associated with the pathogenesis of lung cancer, but the role of the RMRP/miR-613 axis in NSCLC has not been studied.

Methods

In this report, we measured the levels of RMRP in clinical NSCLC samples and cell lines. The target gene of RNA was predicted by online tools and verified by Luciferase reporter assay. Moreover, the function and regulatory mechanism of RMRP in the progression of cancer were further investigated.

Results

Our data showed that the expression of RMRP in NSCLC tissues and cell lines was both up-regulated. Functionally, RMRP promoted the proliferation and metastasis of A549 and H1299 cells. Luciferase reporter assay confirmed that RMRP was the sponger of miR-613, and NFAT5 is the direct target of miR-613. Functional acquisition and loss-of-function strategies further confirmed that RMRP induces the up-regulation of NFAT5 expression through competitive binding with miR-613, leading to promote the progression and metastasis potential of lung cancer cells.

Conclusion

Collectively, our findings emphasized the importance of RMRP in the development of NSCLC, which may provide a new therapeutic target and potential diagnostic biomarker for NSCLC therapy.

PI3K-AKT-mTOR pathway alterations in advanced NSCLC patients after progression on EGFR-TKI and clinical response to EGFR-TKI plus everolimus combination therapy

Background

Several mechanisms including abnormal activation of PI3K-AKT-mTOR pathway have been proved to generate acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC). In this study, we investigated the genomic characteristics of PI3K pathway activated in NSCLC patients after progression on EGFR-TKIs and whether both targeting EGFR and PI3K pathway could overcome resistance.

Methods

A total of 605 NSCLC cases with a history of EGFR TKI treatment were reviewed, in which 324 patients harboring EGFR mutations were confirmed progression on at least one EGFR TKI and finally enrolled. Tumor tissues or blood samples were collected at the onset of TKI progression for next generation sequencing (NGS). Six EGFR mutant patients with co-occurring mutations in PI3K pathway were retrospectively collected to assess the effect of EGFR TKI plus everolimus, a mTOR inhibitor.

Results

Forty-nine (14.9%) patients resistant to EGFR TKIs have at least one genetic variation in PI3K pathway. PIK3CA, PTEN and AKT1 variations were detected in 31 (9.5%), 18 (5.5%) and 3 (0.9%) of patients, respectively. No significant differences were observed in distribution of PI3K pathway alterations among patients with different EGFR mutations (EGFR exon19 deletion mutations/EGFR L858R/uncommon EGFR mutations) and among patients resistant to different EGFR TKIs. For patients treated with everolimus and EGFR-TKI, five (5/6, 83.3%) achieved stable disease (SD) and one (1/6, 16.7%) didn’t receive disease control. The median progression-free survival (PFS) was 2.1 months (95% confidence interval, 1.35–4.3 months, range, 0.9–4.4 months). The most common adverse events were dental ulcer (6/6), rash (1/6).

Conclusions

Our study revealed that PI3K pathway was activated in at least 14.9% in EGFR-TKI resistant patients. EGFR-TKIs plus everolimus showed limited antitumor activity in EGFR mutant NSCLC patients with PI3K pathway aberrations.

MiR-1299 Impedes the Progression of Non-Small-Cell Lung Cancer Through EGFR/PI3K/AKT Signaling Pathway

Background

Non-small-cell lung cancer (NSCLC) is one of the most malignant tumors. In which, numerous miRNAs had been reported to participate in the pathogenesis. However, the expression and function of miR-1299 in NSCLC are not clear.

Methods

To explore the roles of miR-1299 in NSCLC, we detected the levels of miR-1299 in clinical samples of NSCLC and investigated the role of miR-1299 in the regulation of the NSCLC cells proliferation, metastasis, and EMT. Luciferase reporter assay was employed to verify the target of miR-1299. Additionally, the proliferation, metastasis, and EMT of A549 and H1299 cells were analyzed after the overexpression and knockdown of miR-1299.

Results

We found that the miR-1299 expression negatively corresponded with the clinical stage and overall survival in NSCLC patients. Overexpression of miR-1299 inhibited the migration, invasion, and EMT of A549 and H1975 cells. Meanwhile, we proved that miR-1299 is the sponge of EGFR. Besides, our results suggested that miR-1299 inhibits the progression of NSCLC cells through the PI3K/Akt signal pathway.

Conclusion

We demonstrated that miR-1299 inhibits the progression of NSCLC through the EGFR/PI3K/Akt signal pathway. Therapeutic intervention targeting the miR-1299 may provide a potential strategy for the treatment of NSCLC.

Identification of MMP1 as a potential gene conferring erlotinib resistance in non-small cell lung cancer based on bioinformatics analyses

BACKGROUND

Non-small cell lung cancer (NSCLC) is the major type of lung cancer with high morbidity and poor prognosis. Erlotinib, an inhibitor of epidermal growth factor receptor (EGFR), has been clinically applied for NSCLC treatment. Nevertheless, the erlotinib acquired resistance of NSCLC occurs inevitably in recent years.

METHODS

Through analyzing two microarray datasets, erlotinib resistant NSCLC cells microarray (GSE80344) and NSCLC tissue microarray (GSE19188), the differentially expressed genes (DEGs) were screened via R language. DEGs were then functionally annotated by Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, which up-regulated more than 2-folds in both datasets were further functionally analyzed by Oncomine, GeneMANIA, R2, Coremine, and FunRich.

RESULTS

We found that matrix metalloproteinase 1 (MMP1) may confer the erlotinib therapeutic resistance in NSCLC. MMP1 highly expressed in erlotinib-resistant cells and NSCLC tissues, and it associated with poor overall survival. In addition, MMP1 may be associated with COPS5 and be involve in an increasing transcription factors HOXA9 and PBX1 in erlotinib resistance.

CONCLUSIONS

Generally, these results demonstrated that MMP1 may play a crucial role in erlotinib resistance in NSCLC, and MMP1 could be a prognostic biomarker for erlotinib treatment.

Non-small cell lung cancer patients with ex19del or exon 21 L858R mutation: distinct mechanisms, different efficacies to treatments

With the development of antitumor therapies, different treatment methods including monotherapy and combined therapy have achieved clinical efficacy in advanced epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC) patients. Exon 19 deletion (ex19del) and exon 21 L858R mutation are common sensitive subtypes of EGFR mutation. However, potential distinct mechanisms are found from several dimensions including molecular structures, biological behaviors, concomitant mutations, resistance mechanisms and tumor mutation burdens. More evidence indicates the prognostic difference of EGFR subgroups. This review focused on the progress of potential distinct mechanisms and outcomes in clinical trials of advanced NSCLC patients with ex19del or exon 21 L858R mutation.

Exosomal long non-coding RNA MSTRG.292666.16 is associated with osimertinib (AZD9291) resistance in non-small cell lung cancer

Acquired resistance of osimertinib is encountered in clinic treatment of non-small cell lung cancer (NSCLC). However, the molecular mechanisms of osimertinib resistance are not fully revealed. This study aimed to investigate the roles of exosomes in delivering osimertinib resistance in NSCLC. Exosomes were successfully isolated. LncRNA sequencing identified a total of 123 differentially expressed lncRNAs, including 45 upregulated lncRNAs and 78 downregulated lncRNAs. The relative expression level of lncRNA MSTRG.292666.16 was significantly upregulated in osimertinib-resistant plasma, osimertinib-resistant H1975R cells and their derived exosomes, compared with those in osimertinib- sensitive plasma, H1975 cells and exosomes (P < 0.05). Besides, osimertinib-resistant exosomes could regulate gene expressions induced by osimertinib, including miRNA-21, miRNA-125b, TGFβ, ARF6 and c-Kit. Osimertinib-resistant exosomes could be taken up by osimertinib-sensitive H1975 cells and resulting in osimertinib-resistance in vivo. Knockdown of lncRNA MSTRG.292666.16 decreased osimertinib resistance of H1975R cells. Our results suggest that exosomal lncRNA MSTRG.292666.16 might be associated with osimertinib resistance in NSCLC.