Transformation from non-small-cell lung cancer to small-cell lung cancer: molecular drivers and cells of origin

Exploring the association between aging, ferroptosis, and common age-related diseases

Aging is a natural biological process that is characterized by the progressive decline in physiological functions and an increased vulnerability to age-related diseases. The aging process is driven by different cell and molecular mechanisms. It has recently been shown that aging is associated with heightened vulnerability to ferroptosis (an intracellular iron-dependent form of programmed cell death). This susceptibility arises from various factors including oxidative stress, impaired antioxidant defences, and dysregulated iron homeostasis. The progressive decline in cellular antioxidant capacity and the accumulation of damaged components contribute to the increased susceptibility of aging cells to ferroptosis. Dysregulation of key regulators involved in ferroptosis, such as glutathione peroxidase 4 (GPX4), iron regulatory proteins, and lipid metabolism enzymes, further exacerbates this vulnerability. The decline in cellular defence mechanisms against ferroptosis during aging contributes to the accumulation of damaged cells and tissues, ultimately resulting in the manifestation of age-related diseases. Understanding the intricate relevance between aging and ferroptosis holds significant potential for developing strategies to counteract the detrimental effects of aging and age-related diseases. This will subsequently act to mitigate the negative consequences of aging and improving overall health in the elderly population. This review aims to clarify the relationship between aging and ferroptosis, and explores the underlying mechanisms and implications for age-related disorders, including neurodegenerative, cardiovascular, and neoplastic diseases. We also discuss the accumulating evidence suggesting that the imbalance of redox homeostasis and perturbations in iron metabolism contribute to the age-associated vulnerability to ferroptosis.

Molecular mechanisms and therapeutic strategies for small‑cell lung cancer transformation after TKI therapy in EGFR‑mutated lung adenocarcinoma (Review)

Lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutations is a common subtype of non-small cell lung cancer (NSCLC). Although it responds well to EGFR-tyrosine kinase inhibitors (EGFR-TKIs), acquired resistance to EGFR-TKIs inevitably occurs, which limits the use of the EGFR-TKIs. One resistance mechanism is small-cell transformation, which refers to the histological switch of EGFR-mutant lung adenocarcinoma to a small-cell lung cancer phenotype following TKI exposure. Small cell transformation is associated with a poor prognosis and requires different treatment modalities compared with NSCLC. The molecular mechanisms underlying small cell transformation are not fully elucidated, but may involve the loss of tumor suppressor genes, such as RB1 and TP53, and the activation of neuroendocrine pathways. In the present review, the current advances in the molecular characteristics and therapeutic regimens for small-cell transformation in patients with EGFR-mutated lung adenocarcinoma who are resistant to EGFR-TKIs, are summarized.

Challenges of small cell lung cancer heterogeneity and phenotypic plasticity

Small cell lung cancer (SCLC) is an aggressive neuroendocrine malignancy with ~7% 5-year overall survival reflecting early metastasis and rapid acquired chemoresistance. Immunotherapy briefly extends overall survival in ~15% cases, yet predictive biomarkers are lacking. Targeted therapies are beginning to show promise, with a recently approved delta-like ligand 3 (DLL3)-targeted therapy impacting the treatment landscape. The increased availability of patient-faithful models, accumulating human tumour biobanks and numerous comprehensive molecular profiling studies have collectively facilitated the mapping and understanding of substantial intertumoural and intratumoural heterogeneity. Beyond the almost ubiquitous loss of wild-type p53 and RB1, SCLC is characterized by heterogeneously mis-regulated expression of MYC family members, yes-associated protein 1 (YAP1), NOTCH pathway signalling, anti-apoptotic BCL2 and epigenetic regulators. Molecular subtypes are based on the neurogenic transcription factors achaete-scute homologue 1 (ASCL1) and neurogenic differentiation factor 1 (NEUROD1), the rarer non-neuroendocrine transcription factor POU class 2 homeobox 3 (POU2F3), and immune- and inflammation-related signatures. Furthermore, SCLC shows phenotypic plasticity, including neuroendocrine-to-non-neuroendocrine transition driven by NOTCH signalling, which is associated with disease progression, chemoresistance and immune modulation and, in mouse models, with metastasis. Although these features pose substantial challenges, understanding the molecular vulnerabilities of transcription factor subtypes, the functional relevance of plasticity and cell cooperation offer opportunities for personalized therapies informed by liquid and tissue biomarkers.

Single-cell multimodal analysis reveals tumor microenvironment predictive of treatment response in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) constitutes over 80% of lung cancer cases and remains a leading cause of cancer-related mortality worldwide. Despite the advent of immune checkpoint inhibitors, their efficacy is limited to 27 to 45% of patients. Identifying likely treatment responders is essential for optimizing healthcare and improving quality of life. We generated multiplex immunofluorescence (mIF) images, histopathology, and RNA sequencing data from human NSCLC tissues. Through the analysis of mIF images, we characterized the spatial organization of 1.5 million cells based on the expression levels for 33 biomarkers. To enable large-scale characterization of tumor microenvironments, we developed NucSegAI, a deep learning model for automated nuclear segmentation and cellular classification in histology images. With this model, we analyzed the morphological, textural, and topological phenotypes of 45.6 million cells across 119 whole-slide images. Through unsupervised phenotype discovery, we identified specific lymphocyte phenotypes predictive of immunotherapy response. Our findings can improve patient stratification and guide selection of effective therapeutic regimens.

Epigenomic analysis identifies DTP subpopulation using HOPX to develop targeted therapy resistance in lung adenocarcinoma

Genomic studies have identified oncogenic drivers in lung cancer, enabling effective targeted therapies. However, patients who initially respond inevitably experience regrowth. The drug-tolerant persister (DTP) stage is a key source of non-genetic resistance, yet its epigenetic regulation remains unclear. Using single-cell chromatin accessibility profiling (scATAC-seq), we identified two distinct DTP subpopulations in EGFR- and KRAS-inhibited models. The integrative network and pathway analysis revealed that one subpopulation is associated with cell cycle, while the other is enriched in developmental pathways. HOPX was the most enriched alveolar signature gene in the latter. It was transiently upregulated with cytoplasmic-to-nuclear translocation, and its deletion significantly delayed DTP regrowth. Mechanistically, HOPX regulates NF-κB activation and repressive histone modifications. Combining targeted therapy with NF-κB or histone-methyltransferase inhibitors nearly abolished DTP regrowth. These findings highlight a potential anti-relapse strategy by targeting developmental pathways to modulate key lineage factors during lung regeneration in patients relapsing on targeted therapy.

Overexpression or knockdown of the P2X7 receptor regulates the progression of non-small cell lung cancer, involving GSK-3β and JNK signaling pathways

Studies have indicated that P2X7 receptor are involved in the progression of non-small cell lung cancer (NSCLC). Therefore, this study sought to explore how modulating P2X7 receptor expression levels affect the biological function of NSCLC and its underlying mechanisms. Recombinant plasmids with P2X7 receptor overexpression or knockdown were constructed and transfected into LLC and LA795 cells, and the biological function changes of these two cells were assessed in vitro. Subsequently, stable cell lines (overexpression or knockdown of P2X7 receptor) were screened, and their tumorigenicity was detected in vivo. The findings of this study demonstrate that both LLC and LA795 cells expressed functional P2X7 receptors, and overexpression of P2X7 receptors promoted the migration and invasion of LLC and LA795 cells. Conversely, the knockdown of the P2X7 receptor yielded contrasting effects. The mechanism involved phosphatidylinositol 3-kinase/protein kinase B/glycogen synthase kinase 3 beta (PI3K/Akt/GSK-3β), c-Jun N-terminal kinase (JNK) signaling pathway and epithelial-mesenchymal transition (EMT). In addition, the knockdown of the P2X7 receptor suppressed cell proliferation and promoted apoptosis in both cells (LLC and LA795). In vivo experiments corroborated these findings, demonstrating that overexpression of the P2X7 receptor promoted tumor growth while its knockdown inhibited tumor growth. The expression levels of related signaling proteins (PI3K/Akt/GSK-3β, JNK, and EMT) in vivo were consistent with the trends observed in vitro. In conclusion, our results suggest that downregulating P2X7 receptor expression can effectively suppress tumor growth, invasion, and migration in NSCLC. Our results suggest that the P2X7 receptor has the potential as a therapeutic target for NSCLC.

Evaluating the polypharmacological potency of indenopyrazole against lung cancer oxidoreductase, chaperone, transferase, and hydrolase proteins

Lung cancer, the deadliest malignancy worldwide, causes 2.2 million cases and 1.8 million deaths annually, accounting for 18% of cancer deaths. Limited early detection, unaffordable treatments, and drug resistance lead to low survival rates, highlighting the urgent need for developing effective, resistance-proof therapies. In this study, we docked the DrugBank library against Lung Cancer Oxidoreductase, Chaperone, Transferase, and Hydrolase Proteins to identify a multitargeted drug candidate, resulting in identifying a promising drug candidate named Indenopyrazole with docking and MM\GBSA scores ranging from -7.337 to -11.62 and -17.82 to -60.38 kcal/mol, respectively. We also evaluated the interaction pattern of the drug candidate with Molecular Interaction Fingerprints and found that the most interacting residues with its counts are 4TRP, 3ASP, 3GLN, 3GLU, 3LYS, 3PHE, and 3TYR. The pharmacokinetics and comparison with standard values supported the candidate, followed by the density functional theory computations. The study was also validated for the WaterMap for water thermodynamics, and its role in binding pockets has also supported the idea that Indenopyrazole has a multitargeted potency. Further, we extended our studies with 100ns MD Simulation in water to analyse the deviations, fluctuations, and intermolecular interactions, and all the 1000 trajectories were evaluated for total complex energy and binding free energy with MM\GBSA concluding wonderful promising results in support of Indenopyrazole as a multitargeted drug candidate-however, its efficacy needs to be experimentally validated.

Evaluating the polypharmacological potency of FEDPN from ChEMBL BioAssays against lung cancer EGFR, ALK, TrkA and KRAS proteins

Lung cancer causes over 2.2 million cases and 1.8 million deaths annually, and the survival rate remains dismal despite therapeutic advancements, highlighting the urgent need for novel drugs. Current single-target treatments are often ineffective due to complex cancer mechanisms and rapid resistance, underscoring the necessity for multitargeted drugs which target multiple pathways simultaneously, enhance therapeutic outcomes, reduce resistance, and significantly improve patient survival. Our study has innovative strategies imperative to achieve these goals and revolutionise lung cancer treatment. In this study, we downloaded the Lung Cancer BioAssays from ChEMBL, categorised them in Active and Inactive, and selected the Active to preprocess, followed by preparing with LigPrep for docking and chosen transferase, and hydrolase proteins (EGFR, ALK, TrkA and KRAS) involved in lung cancer pathways and docked them which identified the best candidate among Active BioAssays 5-fluoro-(2R*,3S*)-2,3-bis(4-hydroxyphenyl)pentanenitrile (FEDPN) as a multitargeted drug candidate. We also evaluated the results with MIFs, which identified VAL, GLU, GLY, LEU, LYS, THR, and TYR as the most interacted residues. We also performed the DFT studies followed by 5 ns WaterMap computations to understand FEDPN's stability, precise interactions, and water thermodynamics on the interacting site. Also, we performed a 100 ns MD simulation in the TIP3P water model and analysed deviation, fluctuations within 2 Å, and many intermolecular interactions followed by binding free energy computations and analysis that supported the results. The complete study backed FEDPN's multitargeted potency-however, experimental studies are needed before its use.

APOBEC3 Activity Promotes the Survival and Evolution of Drug-Tolerant Persister Cells during EGFR Inhibitor Resistance in Lung Cancer

APOBEC mutagenesis is one of the most common endogenous sources of mutations in human cancer and is a major source of genetic intratumor heterogeneity. High levels of APOBEC mutagenesis are associated with poor prognosis and aggressive disease across diverse cancers, but the mechanistic and functional impacts of APOBEC mutagenesis on tumor evolution and therapy resistance remain relatively unexplored. To address this, we investigated the contribution of APOBEC mutagenesis to acquired therapy resistance in a model of EGFR-mutant non-small cell lung cancer. We find that inhibition of EGFR in lung cancer cells leads to a rapid and pronounced induction of APOBEC3 expression and activity. Functionally, APOBEC expression promotes the survival of drug-tolerant persister cells (DTP) following EGFR inhibition. Constitutive expression of APOBEC3B alters the evolutionary trajectory of acquired resistance to the EGFR inhibitor gefitinib, making it more likely that resistance arises through de novo acquisition of the T790M gatekeeper mutation and squamous transdifferentiation during the DTP state. APOBEC3B expression is associated with increased expression of the squamous cell transcription factor ΔNp63 and squamous cell transdifferentiation in gefitinib-resistant cells. Knockout of p63 in gefitinib-resistant cells reduces the expression of the ΔNp63 target genes IL-1α/β and sensitizes these cells to the third-generation EGFR inhibitor osimertinib. These results suggest that APOBEC activity promotes acquired resistance by facilitating evolution and transdifferentiation in DTPs and that approaches to target ΔNp63 in gefitinib-resistant lung cancers may have therapeutic benefit.

SIGNIFICANCE

APOBEC mutagenesis is a common source of genetic heterogeneity in cancer, and APOBEC mutational signatures are enriched in metastatic and drug-resistant tumors. However, the mechanisms through which APOBEC3 enzymes promote tumor evolution remain unknown. In this study, we show that APOBEC3 activity contributes to the development of therapy-resistant cancer cells by promoting evolution of DTP cells. These findings offer insights into the role of APOBEC mutagenesis in cancer progression.

LSD1 inhibition attenuates targeted therapy-induced lineage plasticity in BRAF mutant colorectal cancer

BACKGROUND

BRAF activating mutations occur in approximately 10% of metastatic colorectal cancer (CRCs) and are associated with worse prognosis in part due to an inferior response to standard chemotherapy. Standard of care for patients with refractory metastatic BRAFV600E CRC is treatment with BRAF and EGFR inhibitors and recent FDA approval was given to use these inhibitors in combination with chemotherapy for patients with treatment naïve metastatic BRAFV600E CRC. Lineage plasticity to neuroendocrine cancer is an emerging mechanism of targeted therapy resistance in several cancer types. Enteroendocrine cells (EECs), the neuroendocrine cell of the intestine, are uniquely present in BRAF mutant CRC as compared to BRAF wildtype CRC.

METHODS

BRAF plus EGFR inhibitor treatment induced changes in cell composition were determined by gene expression, imaging and single cell approaches in multiple models of BRAF mutant CRC. Furthermore, multiple clinically relevant inhibitors of the lysine demethylase LSD1 were tested to determine which inhibitor blocked the changes in cell composition.

RESULTS

Combined BRAF and EGFR inhibition enriched for EECs in all BRAF mutant CRC models tested. Additionally, EECs and other secretory cell types were enriched in a subset of BRAFV600E CRC patient samples following targeted therapy. Importantly, inhibition of LSD1 with a clinically relevant inhibitor attenuated targeted therapy-induced EEC enrichment through blocking the interaction of LSD1, CoREST2 and STAT3.

CONCLUSIONS

Our findings that BRAF plus EGFR inhibition induces lineage plasticity in BRAFV600E CRC represents a new paradigm for how resistance to BRAF plus EGFR inhibition occurs. Additionally, our finding that LSD1 inhibition blocks lineage plasticity has the potential to improve responses to BRAF plus EGFR inhibitor therapy in patients.

Small Extracellular Vesicle (sEV) Uptake from Lung Adenocarcinoma and Squamous Cell Carcinoma Alters T-Cell Cytokine Expression and Modulates Protein Profiles in sEV Biogenesis

BACKGROUND

Despite advances in immunotherapy, non-small-cell lung carcinoma (NSCLC)'s clinical success is limited, possibly due to substantial immunological alterations in advanced cancer patients. This study examines the immunomodulatory effects of sEVs derived from lung adenocarcinoma (ADC) and squamous cell carcinoma (SCC) on T cells.

METHODS

SEVs were isolated from lung cancer cell lines and Jurkat-E6.1. SEV size and morphology were analyzed by NTA and TEM, respectively, while Western blotting confirmed sEV markers. SEV uptake was assessed, followed by resazurin assay, RNA isolation, quantification, cDNA preparation, RT-PCR, nano LC-MS, and bioinformatic analysis, before and after treating Jurkat-E6.1 cells with sEVs from A549 and SKMES1.

RESULTS

Cancer-derived sEVs were efficiently internalized by immune cells, reducing T-cell viability. The real-time PCR analysis showed downregulation of KI67, BCL2, BAX, TNFA, IL6, TGFβ, and IL10, suggesting reduced proliferation, dysregulated apoptosis, and impaired inflammatory and immunosuppressive signaling, and the upregulation of GZMB and IL2 suggests retained cytotoxic potential but possibly dysfunctional T-cell activation. Proteomic analysis revealed 39 differentially abundant proteins (DAPs) in ADC-treated T cells and 276 in SCC-treated T cells, with 19 shared DAPs. Gene Ontology (GO) analysis of these DAPs highlighted processes such as sEV biogenesis, metabolic pathways, and regulatory functions, with ADC sEVs influencing NAD metabolism, ECM binding, and oxidoreductase activity, while SCC sEVs affected mRNA stability, amino acid metabolism, and cadherin binding. The cytoplasmic colocalization suggests the presence of these proteins in the cellular and extracellular lumen, indicating the potential of further release of these proteins in the vesicles by T cells.

CONCLUSION

Lung cancer-derived sEVs regulate T-cell activities through immunoregulatory signaling. The molecular interactions between sEVs and immune cells can reveal novel tumor immune regulatory mechanisms and therapeutic targets.

EGFR-mutant lung adenocarcinoma transformed into small cell Lung cancer: A case report and literatures review

Advances in molecular biology have positioned epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) as highly effective therapies for patients with EGFR-mutant carcinomas. However, the inevitable emergence of acquired resistance significantly limits their long-term efficacy. Among resistance mechanisms, the transformation of lung adenocarcinoma to small cell lung cancer (SCLC) following EGFR-TKIs therapy is an uncommon but clinically important phenomenon contributing to treatment failure. We present a case of SCLC transformation in a patient with EGFR-mutant lung adenocarcinoma after 8 months of first-line osimertinib therapy. Following 4 cycles of etoposide combined with lobaplatin chemotherapy, adenocarcinoma cells regained predominance, illustrating a dynamic histological shift between adenocarcinoma and SCLC phenotypes. Subsequent treatment with 2 cycles of chemotherapy plus osimertinib resulted in disease stabilization. However, multiple brain metastases were identified 3 months after completing 6 cycles of chemotherapy. This case underscores the bidirectional histological plasticity between lung adenocarcinoma and SCLC during treatment and highlights the critical importance of repeated biopsies for guiding management strategies in the context of resistance. We also provide a comprehensive review of the clinical manifestations, underlying mechanisms, predictive biomarkers, and therapeutic approaches for SCLC transformation.

The mechanism of E3 ubiquitin ligase HERC1 regulating ferroptosis in lung adenocarcinoma cells

OBJECTIVE

Lung adenocarcinoma (LUAD) is the most prevalent subtype of lung cancer. Herein, we probed into the role of E3 ubiquitin protein ligase family member 1 (HERC1) in promoting ferroptosis and inhibiting LUAD cell proliferation by regulating RAF proto-oncogene serine/threonine-protein kinase (C-RAF).

METHODS

In cultured human normal lung epithelial cells and non-small cell lung adenocarcinoma cell lines, HERC1 expression was determined by RT-qPCR and Western blot tests. PC-9 and Calu-3 cells were transfected with oe-HERC1, oe-C-RAF or their negative controls. Reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), and Fe2+ levels were assessed by biochemical assays. Cell viability, death, and proliferation were evaluated by CCK-8, LDH and colony formation assays, followed by assessments of HERC1-C-RAF interaction, C-RAF ubiquitin level, and C-RAF protein stability.

RESULTS

HERC1 was poorly expressed in LUAD cells. HERC1 promoted LUAD cell ferroptosis and repressed their proliferation and migration, corresponding to reduced levels of system xc-, GPX4, and GSH, as well as elevated levels of ROS, MDA, Fe2+, and ACSL4. LUAD cells overexpressing HERC1 displayed decreased C-RAF protein level, HERC1-C-RAF interaction, elevated C-RAF ubiquitin level, and accelerated C-RAF protein degradation, indicating that HERC1 facilitated C-RAF ubiquitin degradation and attenuated C-RAF protein stability via interaction with C-RAF. C-RAF overexpression partially abrogated the regulatory impact of HERC1 on LUAD cell ferroptosis and proliferation.

CONCLUSION

HERC1 expedites C-RAF ubiquitin degradation by interacting with C-RAF, which consequently promotes ferroptosis, thereby inhibiting LUAD cell proliferation.

Brief Report: The Genomic Landscape of Small Cell Lung Cancer in Never-Smoking Patients

BACKGROUND

Small cell lung cancer (SCLC) predominantly develops in patients with significant smoking history, and patients who have no history of tobacco exposure remain understudied. Prior reports have suggested that SCLC in never-smoking patients may have unique genomic traits.

METHODS

We retrospectively analyzed records from the Tempus clinicogenomic database to identify SCLC patients reporting "never smoking" (NS, n = 54) or "current/former smoking" (C/FS, n = 608) status. Tumors were sequenced with the Tempus xT assay, including a targeted 648-gene DNA panel and whole exome capture RNA-seq. Tumor immune cell infiltration was estimated from RNA expression data and PD-L1 expression status was determined by immunohistochemistry.

RESULTS

Compared with CF/S patients, NS patients were more likely to be female (70% vs. 55%). Tumors of NS patients had a lower prevalence of TP53 mutations (59% vs. 85%) but no significant difference in RB1 mutations (57% vs. 63%). NS patients had a higher prevalence of EGFR (26% vs. 2.6%), PIK3CA (15% vs. 3.6%), and OS9 (5.6% vs. 0.0%) mutations. Similar findings were observed even after removing cases of transformation from non-small cell lung cancer (NSCLC) or combined SCLCNSCLC presentations. In addition, tumors of NS patients had a lower tumor mutation burden and decreased immune cell infiltration, including by CD4+ and CD8+ T cells.

CONCLUSION

The mutational landscape of SCLC in NS patients significantly differs from that of C/FS patients, suggesting that the occurrence of SCLC in NS patients may represent a distinct genomic entity.

Increasing cisplatin exposure promotes small-cell lung cancer transformation after a shift from glucose metabolism to fatty acid metabolism

OBJECTIVES

Lung cancer is a leading cause of global cancer mortality. Clinical observations reveal that histological transformation from non-small cell lung cancer (NSCLC) to small cell lung cancer (SCLC) is accompanied by mutations in TP53 and RB1. By applying gradually increasing cisplatin concentrations to mimic the escalating drug pressure within the tumor microenvironment, this study investigated the link between phenotypic transformation to SCLC in cisplatin-resistant human lung adenocarcinoma cells and alterations in cellular energy production pathways.

MATERIALS AND METHODS

We established two cisplatin-resistant NSCLC cell lines with varying resistance levels. RNAseq analyses identified TP53 and RB1 gene mutations. Comprehensive functional assays were performed to characterize A549/DDP1 μg/mL and A549/DDP3 μg/mL cells, focusing on proliferation and migratory capabilities. Cellular bioenergetics were assessed through glycolysis and oxidative phosphorylation analyses. Western blotting was employed to examine epithelial-mesenchymal transition (EMT), glucose metabolism, and lipid metabolism markers. Cell cycle distribution was analyzed by flow cytometry. Additionally, a xenograft mouse model was developed for in vivo validation.

RESULTS

TP53 and RB1 mutations were associated with cisplatin concentration-dependent phenotypic transformation, with A549/DDP cells acquiring a more aggressive SCLC-like phenotype (In the article we call the A549/DDPSCLC cells). Analysis of cell bioenergetics profiling and Western blot analyses revealed enhanced glucose metabolism in A549/DDP1 μg/mL cells, while A549/DDPSCLC cells exhibited predominant lipid metabolism. Compound3K and Etomoxir specifically inhibit the activity of PKM2 and CPT1A, respectively, with Etomoxir demonstrating substantially inhibited A549/DDPSCLC cells growth and more cell cycle arrest in the G0/G1 phase. Combinatorial of Compound3K and Etomoxir effectively induced cell death in A549/DDPSCLC phenotype cells in vitro. Etomoxir alone or combined with Compound3K significantly inhibited tumor growth in vivo, with enhanced efficacy in the combination group.

CONCLUSIONS

This study provides the first evidence of cisplatin concentration-dependent metabolic reprogramming during NSCLC-to-SCLC transformation. We identified a phenotypic transition from NSCLC to SCLC accompanied by a metabolic shift from glucose to fatty acid metabolism, offering new insights into therapeutic strategies for treatmentresistant lung cancer.

Deep Clustering-Based Metabolic Stratification of Non-Small Cell Lung Cancer Patients Through Integration of Somatic Mutation Profile and Network Propagation Algorithm

As a common malignancy of the lower respiratory tract, non-small cell lung cancer (NSCLC) represents a major oncological challenge globally, characterized by high incidence and mortality rates. Recent research highlights the critical involvement of somatic mutations in the onset and development of NSCLC. Stratification of NSCLC patients based on somatic mutation data could facilitate the identification of patients likely to respond to personalized therapeutic strategies. However, stratification of NSCLC patients using somatic mutation data is challenging due to the sparseness of this data. In this study, based on sparse somatic mutation data from 4581 NSCLC patients from the Memorial Sloan Kettering Cancer Center (MSKCC) database, we systematically evaluate the metabolic pathway activity in NSCLC patients through the application of network propagation algorithm and computational biology algorithms. Based on these metabolic pathways associated with prognosis, as recognized through univariate Cox regression analysis, NSCLC patients are stratified using the deep clustering algorithm to explore the optimal classification strategy, thereby establishing biologically meaningful metabolic subtypes of NSCLC patients. The precise NSCLC metabolic subtypes obtained from the network propagation algorithm and deep clustering algorithm are systematically evaluated and validated for survival benefits of immunotherapy. Our research marks progress towards developing a universal approach for classifying NSCLC patients based solely on somatic mutation profiles, employing deep clustering algorithm. The implementation of our research will help to deepen the analysis of NSCLC patients' metabolic subtypes from the perspective of tumor microenvironment, providing a strong basis for the formulation of more precise personalized treatment plans.

A Recurrent Small Cell Lung Carcinoma Harboring an EML4-ALK Fusion Mutation with Sustained Response to Ensartinib: A Case Report

Small cell lung cancer (SCLC) is an aggressive neuroendocrine tumor. Lung cancer patients with ALK and EML4 fusions respond significantly to ALK inhibitors. The EML4-ALK fusion gene mutation is the result of an inversion of chromosome 2, which juxtaposes the 5 end of the EML4 gene with the 3 end of the ALK gene. In SCLC, the frequency of fusion genes is very low, and to the best of our knowledge, only four cases of ALK fusion gene mutations in SCLC have been reported. In this report, we describe the treatment of a 74-year-old female patient with SCLC who developed recurrence of hilar lymph node metastasis three years after surgical resection. Postoperative NGS showed that this patient is a SCLC patient harboring a rare EML4-ALK fusion mutation, and a satisfactory 43-month overall survival (OS) was achieved after treatment with ensartinib targeting the EML4-ALK fusion gene mutation. The ALK-TKI may be a new treatment option for these patients. This article provides a therapeutic reference.

Disentangling the effects of various risk factors and trends in lung cancer mortality

Lung cancer is a leading cause of mortality in oncological classifications, yet the impact of various risk factors on lung cancer mortality (LCM) in non-smokers remains unclear. This study aims to weigh out the diverse impact of multiple risk factors on LCM rates and identify trends in LCM rates worldwide. We initially employed Random Forest Tree (RFT) and Gradient Boosting Regression (GBR) to identify common primary factors influencing LCM. After eliminating four common primary factors, a comparative analysis between partial and Pearson correlations was conducted to filter out significant factors in the correlations between risk factors and LCM rates across 204 countries from 2005 to 2019. The findings show that excluding the impacts of occupational exposure to arsenic, smoking, residential radon, occupational exposure to silica, occupational exposure to asbestos, high systolic blood pressure, secondhand smoke, child wasting, and alcohol use had a considerably greater impact on LCM than particular matter pollution (PM2.5). Furthermore, a Multiple Joinpoint Regression analysis identified increasing trends of LCM rates in the 142 countries (e.g., China and India); decreasing trends in 38 countries (e.g., Denmark and Norway), and stable trends in 24 countries (e.g., Sudan, Mali, and Australia). This research suggests that in addition to considering the effects of occupational exposure to arsenic, smoking, residential radon, and occupational exposure to silica on LCM rates, occupational exposure to asbestos, high systolic blood pressure, secondhand smoke, child wasting, and alcohol use should be considered in lung cancer prevention strategies, especially in countries with increasing trends of LCM rates.

Partial transformation from non-small cell lung cancer to small cell lung cancer: a case report and literatures review

A fraction of lung adenocarcinoma patients with gene mutations who receive targeted therapy would experience acquired resistance and undergo small cell lung cancer (SCLC) transformation. The mechanisms behind the transformation of tumor pathological types and the treatment strategies are not fully clear. There have been case reports of the transformation from adenocarcinoma to SCLC, but the partial transformation from adenocarcinoma to SCLC has not been reported. We reported a case of a patient with partial transformation from lung adenocarcinoma to SCLC for the first time. The patient was diagnosed as lung adenocarcinoma with epidermal growth factor receptor (EGFR) 19 exon mutation and Tumor protein p53 (TP53) mutation. She received Epithelial growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) treatment. However, the tumor progression occurred and the lung aspiration pathology revealed a transformation from non-small cell lung cancer (NSCLC) to SCLC. The treatment regimen was changed to cisplatin and etoposide (EP) chemotherapy, resulting in a 2-month PFS. It was worth mentioning that adenocarcinoma cells were found in the patient's emerging pericardial effusion, suggesting the co-existence of both adenocarcinoma and SCLC components. This is the first report of partial transformation from NSCLC to SCLC in the context of definitive pathology. It highlights that when no more pathological biopsy is feasible, we should be alert to the partial transformation and adopt the appropriate treatment.

Transformation of lung adenocarcinoma to small cell lung cancer following osimertinib treatment: a case report and literature review

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) effectively treat EGFR-mutant lung adenocarcinoma, demonstrating initial efficacy but eventually leading to acquired resistance. Small cell transformation is a rare resistance mechanism to EGFR-TKIs in lung adenocarcinoma, which can complicate clinical diagnosis and treatment. We present a patient with lung adenocarcinoma who underwent a prior pneumonectomy and adjuvant chemotherapy and was treated with osimertinib after the recurrence of lung cancer. Small cell transformation occurred approximately 20 months after starting osimertinib treatment. After this transformation, the patient underwent lung radiotherapy and cisplatin-etoposide chemotherapy, which stabilized the disease. Following the confirmation of small cell lung cancer (SCLC) via thyroid puncture, treatments with irinotecan, irinotecan plus atezolizumab, thyroid radiotherapy, adrenal radiotherapy, and head radiotherapy were sequentially administered, yet the disease continued to progress. The patient succumbed to the disease in May 2023 because of progression and organ failure, with an overall survival of 52.7 months, including 16 months post small cell transformation. This case highlights the possibility of osimertinib causing lung adenocarcinoma to transform into SCLC and underscores rebiopsies' importance in identifying resistance mechanisms to EGFR-TKIs. Increased levels of neuron-specific enolase and pro-gastrin releasing peptide can signal early transformation into SCLC.

Clonal driver neoantigen loss under EGFR TKI and immune selection pressures

Neoantigen vaccines are under investigation for various cancers, including epidermal growth factor receptor (EGFR)-driven lung cancers1,2. We tracked the phylogenetic history of an EGFR mutant lung cancer treated with erlotinib, osimertinib, radiotherapy and a personalized neopeptide vaccine (NPV) targeting ten somatic mutations, including EGFR exon 19 deletion (ex19del). The ex19del mutation was clonal, but is likely to have appeared after a whole-genome doubling (WGD) event. Following osimertinib and NPV treatment, loss of the ex19del mutation was identified in a progressing small-cell-transformed liver metastasis. Circulating tumour DNA analyses tracking 467 somatic variants revealed the presence of this EGFR wild-type clone before vaccination and its expansion during osimertinib/NPV therapy. Despite systemic T cell reactivity to the vaccine-targeted ex19del neoantigen, the NPV failed to halt disease progression. The liver metastasis lost vaccine-targeted neoantigens through chromosomal instability and exhibited a hostile microenvironment, characterized by limited immune infiltration, low CXCL9 and elevated M2 macrophage levels. Neoantigens arising post-WGD were more likely to be absent in the progressing liver metastasis than those occurring pre-WGD, suggesting that prioritizing pre-WGD neoantigens may improve vaccine design. Data from the TRACERx 421 cohort3 provide evidence that pre-WGD mutations better represent clonal variants, and owing to their presence at multiple copy numbers, are less likely to be lost in metastatic transition. These data highlight the power of phylogenetic disease tracking and functional T cell profiling to understand mechanisms of immune escape during combination therapies.

Anlotinib induced ferroptosis through the p53/xCT/GPX4 pathway in non-small cell lung cancer

Anlotinib, an anti-angiogenic agent, has demonstrated significant anti-tumor effects in non-small cell lung cancer (NSCLC). However, whether anlotinib exerts its anti-tumor activity in NSCLC through ferroptosis, and its underlying mechanisms, remain unclear. This study revealed that anlotinib effectively inhibited the proliferation of NSCLC cells in a time- and dose-dependent manner. Treatment with anlotinib resulted in increased levels of ferroptosis targets (lipid reactive oxygen species and malondialdehyde) and p53 protein expression, while decreasing glutathione levels and the protein expression of solute carrier family 7 member 11 (xCT) and glutathione peroxidase 4 (GPX4). Notably, the ferroptosis inhibitor, Ferrostatin-1 (Fer-1), or the p53 inhibitor, Pifithrin-α (PFT-α), reversed the observed effects on ferroptosis induction in NSCLC cells. Consistently, our in vivo studies showed accelerated tumor growth rates for the anlotinib/Fer-1 group and the anlotinib/PFT-α group compared with administration of anlotinib alone. However, anlotinib-induced ferroptosis was suppressed in p53-deficient cells. Collectively, these findings confirm that anlotinib exerts potent anti-tumor effects both in vitro and in vivo by inducing ferroptosis by modulating the p53/xCT/GPX4 pathway specifically within NSCLC cells.

Advances of PET/CT in Target Delineation of Lung Cancer Before Radiation Therapy

In the clinical management of lung cancer, radiotherapy remains a cornerstone of multimodal treatment strategies, often used alongside surgery or in combination with systemic therapies such as chemotherapy, tyrosine kinase inhibitors, and immune checkpoint inhibitors. While conventional imaging modalities like computed tomography (CT) and magnetic resonance imaging (MRI) continue to play a central role in staging, response assessment, and radiotherapy planning, advanced imaging techniques, particularly [18F]FDG PET/CT, are being increasingly integrated into routine clinical practice. These advanced techniques address the limitations of standard imaging by providing insight into molecular and metabolic tumor characteristics, enabling precise tumor visualization, accurate target volume delineation, and early treatment response assessment. This review examines the role of radiotherapy in the multidisciplinary management of lung cancer, detailing current concepts of morphological and functional imaging for staging and treatment planning. It also highlights the growing importance of PET-based radiotherapy planning, emphasizing its contributions to target volume definition and predictive value for treatment outcomes. Recent methodological advances, including the integration of artificial intelligence (AI), radiomics, technical innovations, and novel PET ligands, are discussed, highlighting their potential to improve the precision, efficacy, and personalization of lung cancer radiotherapy planning.

Optimizing Bi-LSTM networks for improved lung cancer detection accuracy

Lung cancer remains a leading cause of cancer-related deaths worldwide, with low survival rates often attributed to late-stage diagnosis. To address this critical health challenge, researchers have developed computer-aided diagnosis (CAD) systems that rely on feature extraction from medical images. However, accurately identifying the most informative image features for lung cancer detection remains a significant challenge. This study aimed to compare the effectiveness of both hand-crafted and deep learning-based approaches for lung cancer diagnosis. We employed traditional hand-crafted features, such as Gray Level Co-occurrence Matrix (GLCM) features, in conjunction with traditional machine learning algorithms. To explore the potential of deep learning, we also optimized and implemented a Bidirectional Long Short-Term Memory (Bi-LSTM) network for lung cancer detection. The results revealed that the highest performance using hand-crafted features was achieved by extracting GLCM features and utilizing Support Vector Machine (SVM) with different kernels, reaching an accuracy of 99.78% and an AUC of 0.999. However, the deep learning Bi-LSTM network surpassed both methods, achieving an accuracy of 99.89% and an AUC of 1.0000. These findings suggest that the proposed methodology, combining hand-crafted features and deep learning, holds significant promise for enhancing early lung cancer detection and ultimately improving diagnosis systems.

Baseline retinoblastoma transcriptional corepressor 1 (Rb1) functional inactivation is a pre-requisite but not sufficient for small-cell histological transformation in epidermal growth factor receptor (EGFR) mutant lung adenocarcinomas post-tyrosine kinase inhibitor therapy

Small-cell transformation is an uncommon mechanism of tyrosine receptor kinase inhibitor (TKI) resistance in epidermal growth factor receptor (EGFR)-mutant lung adenocarcinomas. This study aims to assess the dynamic changes in the molecular landscape and Rb1 functional status in EGFR-mutant lung adenocarcinomas transforming to small-cell carcinomas post-treatment with EGFR-TKIs. This is an ambispective study (2019-2023) wherein the baseline and post-TKI biopsies of EGFR-mutant lung adenocarcinomas with small-cell transformation were subject to Rb1 immunohistochemistry and 72-gene targeted panel next-generation sequencing. Rb1-deficiency was defined as Rb1 protein loss or Rb1retained/p16high/Cyclin-D1low protein expression profile with RB1 mutations. A cohort of EGFR-mutant lung adenocarcinomas without small-cell transformation was included for Rb1 status comparison. Small-cell transformation was diagnosed in 9 patients (10%, 9/84) on their post-TKI biopsy. All their tested baseline adenocarcinoma (n = 7) and post-TKI small-cell carcinoma (n = 9) samples were Rb1-deficient, with additional TP53 (11/11) and PTEN mutations (2/11). Eighteen paired samples from 9 patients without small-cell transformation revealed Rb1-deficiency in one patient (1/9) only. Baseline functional inactivation of Rb1 is nearly universal in EGFR-mutant adenocarcinomas transforming to small-cell carcinomas post-EGFR TKI suggesting that Rb1 loss is prerequisite for small-cell transformation. However, it is likely not sufficient as not all adenocarcinomas with baseline Rb1 loss transform into small-cell carcinomas. Except for TP53 and PTEN, recurrent mutations in other common oncogenes tested were not detected at baseline or at progression. Within the limitation of a small sample size, specific molecular events that drive small-cell transformation remain unclear.

Case report: A patient with EGFR L861Q positive adenosquamous lung carcinoma transforming into large cell neuroendocrine cancer after treatment with Almonertinib

Almonertinib, a third-generation epidermal growth factor receptor tyrosine kinase inhibitor, is selective for both epidermal growth factor receptor tyrosine kinase inhibitor-sensitizing and T790M resistance mutations. However, resistance to the third-generation EGFR-TKIs is still inevitable. Econdary EGFR mutations, and bypass pathway activation have been reported with Almonertinib therapy. This article presents a rare case report of a patient with EGFR L861Q positive adenosquamous lung carcinoma who transformed into large cell neuroendocrine carcinoma following treatment with Almonertinib. The patient exhibited disease progression 8 months after initiating Almonertinib treatment, and a blood genetic test revealed mutations in EGFR L861Q and EGFR L858R. A subsequent lung biopsy after progression confirmed the diagnosis of large cell neuroendocrine carcinoma, and subsequently treatment with cisplatin and etoposide was effective. Transformation into neuroendocrine carcinoma is one of the mechanisms behind resistance to Almonertinib in adenosquamous lung carcinoma. EGFR mutations may persist even after transformation into neuroendocrine carcinoma. For non-small cell lung cancer patients undergoing Almonertinib therapy, this case report emphasizes the importance of performing a timely pathological biopsy upon the emergence of resistance.

Case report: Personalized management of treatment resistance in advanced NSCLC patients with mutated epidermal growth factor receptor: special examples and literature review

The treatment landscape of non-small cell lung cancer (NSCLC) has shifted significantly from empirical, histology-driven, and clinician-directed cytotoxic regimens to a stratified approach predicated on molecular profiling of tumor genetics and immune biomarkers, by the former can indicate targeted therapy that bull's eye hits the arrow, while the latter can hint the benefit amplitude of immune checkpoint inhibitors (ICBs). While third-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) have become the cornerstone of frontline therapy for patients harboring classic sensitive EGFR mutations, all tumors ultimately develop acquired resistance to these approaches, which can be categorized into three primary mechanism subclasses. The first subclass involves the acquisition of target mutations that lead to changes in the kinase domain, thereby hindering drug binding. The second mechanism, known as bypass resistance, entails tumor clones utilizing alternative signaling pathways for proliferation. Lastly, the third acquired mechanism pertains to histological transformation, such as the emergence of small cell lung cancer (SCLC) clones. The transformation of pathological types has brought great confusion to the clinical diagnosis and treatment process. We report a case of advanced lung adenocarcinoma with EGFR-sensitive mutation that transformed into small cell lung cancer after EGFR-TKIs treatment. Subsequent treatment revealed the presence of both adenocarcinoma and small cell carcinoma through needle biopsies at various metastatic sites. Based on the pathological, the patient received combination therapy with anlotinib at different times and achieved a long survival time.

The analysis of molecular classification of pulmonary neuroendocrine tumors and relationship between YAP1 and efficacy

A novel molecular classification for small cell lung cancer (SCLC) has been established utilizing the transcription factors achaete-scute homologue 1 (ASCL1), neurogenic differentiation factor 1 (NeuroD1), POU class 2 homeobox 3 (POU2F3), and yes-associated protein 1 (YAP1). This classification was predicated on the transcription factors. Conversely, there is a paucity of information regarding the distribution of these markers in other subtypes of pulmonary neuroendocrine tumors (PNET). Clinical and survival data for PNET patients were gathered from January 2008 to December 2020. Immunohistochemical analysis was employed to evaluate the expression. The relationship between YAP1 expression and outcomes in patients with pulmonary large cell neuroendocrine carcinoma (LCNEC) was examined. Data from low-grade PNET patients who had previously undergone immunotherapy were retrospectively gathered and analyzed. The ASCL1 positive rate was markedly elevated in SCLC (7.1% vs. 60%; P < 0.001) and LCNEC patients (7.1% vs. 38.5%; P = 0.034) compared to PC patients. The YAP1-positive rate was elevated in LCNEC compared to SCLC (43.6% vs. 20%, P = 0.028) and pulmonary carcinoid (PC) patients (43.6% vs. 21.4%; P = 0.021). The DLL3-positive rate in SCLC patients was greater than in SCLC and PC patients (37.1% vs. 23.1% vs. 0%; P = 0.028, P = 0.021). A significant level of tumor heterogeneity was noted, with SCLC and LCNEC patients exhibiting markedly higher heterogeneity than PC patients (65.7% vs. 56.3% vs. 21.4%; P = 0.005, P = 0.025). In patients with LCNEC, YAP1 positivity exhibited no correlation with PD-L1 expression (17.1% vs. 45.7%, P = 0.518). Tumor heterogeneity was also noted in transformed SCLC, with no significant differences in the expression levels of transcription factors between transformed and traditional SCLC. In 13 LCNEC patients with a history of ICI application, YAP1 exhibited no significant effect on PFS (P = 0.331) or OS (P = 0.17) in the subgroup analysis of LCNEC patients. Among the 14 patients with low-grade PNET who underwent immunotherapy, the disease control rate was 85.7%. Patients with high-grade PNET have high levels of expression of ASCL1 and DLL3, whereas patients with LCNEC have high levels of expression of YAP1. With regard to the transcription factor level, it was found that patients with SCLC and LCNEC had a much higher degree of tumor heterogeneity than those with PC. In patients with LCNEC who were receiving monotherapy of ICIs or chemotherapy in combination with ICIs, the expression of YAP1 did not appear to have any clear impact on the prognosis. This is due to the limited sample size of the study, which requires additional investigation. When compared to the expression of TFs in regular SCLC, the expression of TFs in converted SCLC is comparable.

Recurrence as a small cell lung cancer transformation in a resected stage IIIA EGFR-mutated non-small cell lung cancer treated with adjuvant osimertinib: a case report

Background

Based on improvements in recurrence-free and overall survival, osimertinib is now widely used as an adjuvant treatment in stage II-IIIA non-small cell lung cancer (NSCLC) presenting with a common epithelial growth factor receptor (EGFR) mutation. Histological transformation is a well-known resistance mechanism to osimertinib in EGFR-mutated metastatic NSCLC, but we currently have insufficient data on recurrence mechanisms in the adjuvant context. We present here the case of a patient treated with adjuvant osimertinib and presenting a small cell lung cancer (SCLC) transformation as a recurrence.

Case Description

A 54-year-old man, never-smoker and with no previous medical history, underwent right superior lobectomy with lymph node resection for a pT3N1M0 [stage IIIA, tumor-node-metastasis (TNM) 8th edition] adenocarcinoma. Programmed death-ligand 1 (PD-L1) negative with an EGFR exon 19 deletion. The patient received 4 cycles of adjuvant chemotherapy before starting adjuvant osimertinib 80 mg. After 35 months of adjuvant osimertinib the patient had a local recurrence and the re biopsy showed an SCLC transformation, underlining the importance of careful surveillance and biopsy at the time of recurrence in EGFR-mutated NSCLC.

Conclusions

this case report provides evidence of SCLC transformation while on adjuvant osimertinib, in a pT3N1 EGFR, RB1 and TP53-mutated pulmonary adenocarcinoma. This highlights the importance of biopsy on recurrence and the transformation potential of the EGFR, RB1 and TP53-mutated adenocarcinomas.

Targeting KAT6A/B as a New Therapeutic Strategy for Cancer Therapy

The lysine acetyltransferase 6A (KAT6A, MOZ, MYST3) is a member of the MYST family of protein acetyltransferases, which are essential for different biological processes such as craniofacial, embryonic, stem cell development, and hematopoiesis. KAT6A is an oncogene in human acute myeloid leukemia (AML), and KAT6A overexpression in AML is associated with metastases and poor prognoses. Furthermore, KAT6A mutations play an important role in cancer formation and progression and result in therapeutic resistance in both hematopoietic malignancies and solid tumors. In this review, we discuss the structural and biological functions of KAT6A and summarize the influence of KAT6A in the development of various tumors. In addition, the recent KAT6A/B inhibitors, their anticancer activities, challenges, and perspective of developing KAT6A/B inhibitors as anticancer drug candidates were introduced.

Brigatinib treatment in a patient with advanced NSCLC with XPO1-ALK fusion: a case report

Patients with ALK-rearranged non-small cell lung cancer (NSCLC) who are treated with ALK tyrosine kinase inhibitors (ALK TKIs) have better prognoses. In this case report, we provide evidence of a novel ALK fusion, XPO1-ALK (intergenic), identified by next-generation DNA sequencing in a patient with advanced lung cancer. After 5 months of brigatinib targeted therapy, the patient clearly experienced tumor disintegration, and this treatment resulted in partial remission. To date, this patient has experienced 5 months of progression-free survival after brigatinib treatment. In addition to reporting the identification of a novel ALK fusion, XPO1-ALK (intergenic), and the sensitivity and safety of brigatinib treatment for lung cancer, this study increased the list of known ALK fusion partners in ALK-positive NSCLC. This case report has a significant clinical reference.

Macrophage-derived extracellular vesicles as new players in chronic non-communicable diseases

Macrophages are innate immune cells present in all tissues and play an important role in almost all aspects of the biology of living organisms. Extracellular vesicles (EVs) are released by cells and transport their contents (micro RNAs, mRNA, proteins, and long noncoding RNAs) to nearby or distant cells for cell-to-cell communication. Numerous studies have shown that macrophage-derived extracellular vesicles (M-EVs) and their contents play an important role in a variety of diseases and show great potential as biomarkers, therapeutics, and drug delivery vehicles for diseases. This article reviews the biological functions and mechanisms of M-EVs and their contents in chronic non-communicable diseases such as cardiovascular diseases, metabolic diseases, cancer, inflammatory diseases and bone-related diseases. In addition, the potential application of M-EVs as drug delivery systems for various diseases have been summarized.

Neuroendocrine Transformation as a Mechanism of Resistance to Targeted Lung Cancer Therapies: Emerging Mechanisms and Their Therapeutic Implications

Lung cancer is the leading cause of cancer-related deaths worldwide, highlighting a major clinical challenge. Lung cancer is broadly classified into two histologically distinct subtypes, termed small cell lung cancer (SCLC) or non-small cell lung cancer (NSCLC). Identification of various oncogenic drivers of NSCLC has facilitated the development of targeted therapies that have dramatically improved patient outcomes. However, acquired resistance to these targeted therapies is common, which ultimately results in patient relapse. Several on-target and off-target resistance mechanisms have been described for targeted therapies in NSCLC. One common off-target mechanism of resistance to these therapies is histological transformation of the initial NSCLC into SCLC, a highly aggressive form of lung cancer that exhibits neuroendocrine histology. This mechanism of resistance presents a significant clinical challenge, since there are very few treatments available for these relapsed patients. Although the phenomenon of NSCLC-to-SCLC transformation was described almost 20 years ago, only recently have we begun to understand the mechanisms underlying this therapy-driven response. These recent discoveries will be key to identifying novel biomarkers and therapeutic strategies to improve outcomes of patients that undergo NSCLC-to-SCLC transformation. Here, we highlight these recent advances and discuss the potential therapeutic strategies that they have uncovered to target this mechanism of resistance.

Discovery of novel PDGFR inhibitors targeting non-small cell lung cancer using a multistep machine learning assisted hybrid virtual screening approach

Non-Small Cell Lung Cancer (NSCLC) is a formidable global health challenge, responsible for the majority of cancer-related deaths worldwide. The Platelet-Derived Growth Factor Receptor (PDGFR) has emerged as a promising therapeutic target in NSCLC, given its crucial involvement in cell growth, proliferation, angiogenesis, and tumor progression. Among PDGFR inhibitors, avapritinib has garnered attention due to its selective activity against mutant forms of PDGFR, particularly PDGFRA D842V and KIT exon 17 D816V, linked to resistance against conventional tyrosine kinase inhibitors. In recent years, Machine Learning has emerged as a powerful tool in pharmaceutical research, offering data-driven insights and accelerating lead identification for drug discovery. In this research article, we focus on the application of Machine Learning, alongside the RDKit toolkit, to identify potential anti-cancer drug candidates targeting PDGFR in NSCLC. Our study demonstrates how smart algorithms efficiently narrow down large screening collections to target-specific sets of just a few hundred small molecules, streamlining the hit discovery process. Employing a Machine Learning-assisted virtual screening strategy, we successfully preselected 220 compounds with potential PDGFRA inhibitory activity from a vast library of 1.048 million compounds, representing a mere 0.013% of the original library. To validate these candidates, we employed traditional genetic algorithm-based virtual screening and docking methods. Remarkably, we found that ZINC000002931631 exhibited comparable or even superior inhibitory potential against PDGFRA compared to Avapritinib, which highlights the value of our Machine Learning approach. Moreover, as part of our lead validation studies, we conducted molecular dynamic simulations, revealing critical molecular-level interactions responsible for the conformational changes in PDGFRA necessary for substrate binding. Our study exemplifies the potential of Machine Learning in the drug discovery process, providing a more efficient and cost-effective means of identifying promising drug candidates for NSCLC treatment. The success of this approach in preselecting compounds with potent PDGFRA inhibitory potential highlights its significance in advancing personalized and targeted therapies for cancer treatment.

Cell-free and extrachromosomal DNA profiling of small cell lung cancer

Small cell lung cancer (SCLC) is highly aggressive with poor prognosis. Despite a relative prevalence of circulating tumour DNA (ctDNA) in SCLC, liquid biopsies are not currently implemented, unlike non-SCLC where cell-free DNA (cfDNA) mutation profiling in the blood has utility for guiding targeted therapies and assessing minimal residual disease. cfDNA methylation profiling is highly sensitive for SCLC detection and holds promise for disease monitoring and molecular subtyping; cfDNA fragmentation profiling has also demonstrated clinical potential. Extrachromosomal DNA (ecDNA), that is often observed in SCLC, promotes tumour heterogeneity and chemotherapy resistance and can be detected in blood. We discuss how these cfDNA profiling modalities can be harnessed to expand the clinical applications of liquid biopsy in SCLC.

Determination of osimertinib concentration in rat plasma and lung/brain tissues

OBJECTIVES

The aim of this study was to establish an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the detection of osimertinib in rat plasma, lung and brain tissues.

METHODS

Forty-eight rats were randomly divided into an experimental group (receiving osimertinib at doses of 5, 8, and 10 mg/kg) and a control group. After continuous intragastric administration for 15 days, samples of blood, lung, and brain tissue were collected. Chromatographic separation was achieved using a BEH C18 column with gradient elution, employing a mobile phase of water (containing 0.1% (v/v) formic acid) and acetonitrile. The concentration of osimertinib in the samples was determined using an AB SCIEX 5500 triple quadrupole mass spectrometer operated in positive electrospray ionization (ESI+) and multiple reaction monitoring (MRM) mode.

RESULTS

A UPLC-MS/MS analytical method for determining osimertinib concentrations was successfully established and validated. A linear relationship was observed for osimertinib concentrations in plasma within the range of 1-300 ng/mL, and in lung and brain tissues within the range of 0.5-50 ng/mL. The selectivity, accuracy, precision, matrix effect, extraction recovery, and stability all meet the requirements of methodological validation criteria.

CONCLUSIONS

A rapid and sensitive UPLC-MS/MS method was developed and validated for quantifying osimertinib concentrations in rat plasma, lung, and brain tissues, providing a valuable tool for pharmacokinetic and tissue distribution studies.

Transdifferentiation of Secretory Carcinoma to Metaplastic Carcinoma at Metastatic Site

Secretory carcinoma is a rare breast tumor driven by ETV6::NTRK3 fusion. It has characteristic morphologic features and identification of these tumors is critical as these patients may benefit from TRK inhibitors. Morphologic shift upon treatment has not been reported in secretory carcinoma or other NTRK-driven tumors. Herein we describe a patient with secretory carcinoma showing transdifferentiation into metaplastic carcinoma (spindle cell and squamous cell carcinoma) at the metastatic site following treatment. Identification of these morphologic shifts is crucial for accurate classification and identification of potential resistant mechanisms.

Synergistic inhibitory effect of atmospheric pressure plasma and berberine on non‑small cell lung cancer cells via inducing apoptosis

BACKGROUND

Non-small cell lung cancer (NSCLC) is a type of lung cancer, the incidence and mortality rate have been high, and the use of monotherapy is easy to make patients develop tolerance. Atmospheric pressure plasma (APP) is an emerging technology for killing cancer cells in recent years, and combination of berberine (BBR) mechanism has not been fully elucidated for NSCLC. The article's primary goal is to investigate the effect of combination on NSCLC and its associated characterization.

METHODS AND RESULTS

Antiproliferative effects were detected by cell viability assay and colony formation, and flow cytometry analysis of apoptosis and cycling showed that the combination synergistically induced apoptosis. Then, extracellular reactive oxygen species (ROS)levels and DCFH-DA-based kits examined intracellular ROS levels, and their effects on mitochondrial membrane potential were measured. Study reveals that co-induced apoptosis is associated with ROS accumulation. Subsequently, Western blotting (WB) detected the expression of epidermal growth factor receptor (EGFR), and the important signaling pathway proteins Ras/ERK and AKT/mTOR. Results showed that it could downregulation of EGFR protein expression and inhibit of activation of ERK/AKT signaling pathways. Simultaneous wound healing assay and epithelial-to-mesenchymal transition (EMT) marker detection were performed for the assessment of migration and EMT ability of NSCLC cells. Combination therapy inhibited migration and EMT of NSCLC cells.

CONCLUSION

The results of this study show that the combination can synergistically induce apoptosis of NSCLC by regulating ROS production. EGFR downregulation and AKT/ERK signaling pathway inhibition are linked to the synergistic effect.

The molecular subtypes of small cell lung cancer defined by key transcription factors and their clinical significance

BACKGROUND

Lung cancer, a prevalent and deadly malignancy, is classified into small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). SCLC is further subdivided into four molecular subtypes-SCLC-A, SCLC-N, SCLC-P, and SCLC-I-based on key transcription factor expression.

METHODS

Immunohistochemistry (IHC) was used to assess ASCL1, NEUROD1, and POU2F3 expression in tumor tissues. The H-Score quantified these results. Clinical characteristics, overall survival (OS), progression-free survival (PFS), and treatment responses were analyzed by subtype, and sensitivity to different treatments was assessed. Risk factors were identified through univariate and multivariate analyses.

RESULTS

IHC and H-Score analysis showed that POU2F3 expression was mutually exclusive with ASCL1 or NEUROD1. Subtype distribution was as follows: SCLC-A (40 %), SCLC-N (33 %), SCLC-P (7 %), and SCLC-I (20 %). There were no significant differences in baseline characteristics, OS (p = 0.829), or PFS (p = 0.924) among subtypes. However, the SCLC-I subtype showed a trend toward improved outcomes with platinum-based doublet chemotherapy plus immune checkpoint inhibitors. Multivariate COX regression identified M stage (HR: 1.72, 95 % CI: 1.13-2.63, p = 0.012) and bone metastasis at diagnosis (HR: 1.58, 95 % CI: 1.02-2.43, p = 0.040) as independent risk factors.

CONCLUSION

This study confirmed the SCLC subtyping based on key transcription factors. While no significant differences in OS and PFS among subtypes were found, the SCLC-I subtype showed potential benefit from platinum-based chemotherapy combined with immune checkpoint inhibitors. M stage and bone metastasis at diagnosis were identified as independent risk factors for SCLC.

Integrative study of lung cancer adeno-to-squamous transition in EGFR TKI resistance identifies RAPGEF3 as a therapeutic target

Although adeno-to-squamous transition (AST) has been observed in association with resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) in clinic, its causality, molecular mechanism and overcoming strategies remain largely unclear. We here demonstrate that squamous transition occurs concomitantly with TKI resistance in PC9-derived xenograft tumors. Perturbation of squamous transition via DNp63 overexpression or knockdown leads to significant changes in TKI responses, indicative of a direct causal link between squamous transition and TKI resistance. Integrative RNA-seq, ATAC-seq analyses and functional studies reveal that FOXA1 plays an important role in maintaining adenomatous lineage and contributes to TKI sensitivity. FOXM1 overexpression together with FOXA1 knockout fully recapitulates squamous transition and TKI resistance in both PC9 xenografts and patient-derived xenograft (PDX) models. Importantly, pharmacological inhibition of RAPGEF3 combined with EGFR TKI efficiently overcomes TKI resistance, especially in RAPGEF3high PDXs. Our findings provide novel mechanistic insights into squamous transition and therapeutic strategy to overcome EGFR TKI resistance in lung cancer.

APOBEC3 activity promotes the survival and evolution of drug-tolerant persister cells during acquired resistance to EGFR inhibitors in lung cancer

APOBEC mutagenesis is one of the most common endogenous sources of mutations in human cancer and is a major source of genetic intratumor heterogeneity. High levels of APOBEC mutagenesis are associated with poor prognosis and aggressive disease across diverse cancers, but the mechanistic and functional impacts of APOBEC mutagenesis on tumor evolution and therapy resistance remain relatively unexplored. To address this, we investigated the contribution of APOBEC mutagenesis to acquired therapy resistance in a model of EGFR-mutant non-small cell lung cancer. We find that inhibition of EGFR in lung cancer cells leads to a rapid and pronounced induction of APOBEC3 expression and activity. Functionally, APOBEC expression promotes the survival of drug-tolerant persister cells (DTPs) following EGFR inhibition. Constitutive expression of APOBEC3B alters the evolutionary trajectory of acquired resistance to the EGFR inhibitor gefitinib, making it more likely that resistance arises through de novo acquisition of the T790M gatekeeper mutation and squamous transdifferentiation during the DTP state. APOBEC3B expression is associated with increased expression of the squamous cell transcription factor ΔNp63 and squamous cell transdifferentiation in gefitinib-resistant cells. Knockout of p63 in gefitinib-resistant cells reduces the expression of the ΔNp63 target genes IL1α/β and sensitizes these cells to the third-generation EGFR inhibitor osimertinib. These results suggest that APOBEC activity promotes acquired resistance by facilitating evolution and transdifferentiation in DTPs, and suggest that approaches to target ΔNp63 in gefitinib-resistant lung cancers may have therapeutic benefit.

Histological transformation in lung adenocarcinoma: Insights of mechanisms and therapeutic windows

Histological transformation from lung adenocarcinoma (ADC) to small cell lung carcinoma (SCLC), large cell neuroendocrine carcinoma (LCNEC), squamous cell carcinoma (SCC), and sarcomatoid carcinoma (PSC) after targeted therapies is recognized as a mechanism of resistance in ADC treatments. Patients with transformed lung cancer typically experience a poor prognosis and short survival time. However, effective treatment options for these patients are currently lacking. Therefore, understanding the mechanisms underlying histological transformation is crucial for the development of effective therapies. Hypotheses including intratumoral heterogeneity, cancer stem cells, and alteration of suppressor genes have been proposed to explain the mechanism of histological transformation. In this review, we provide a comprehensive overview of the known molecular features and signaling pathways of transformed tumors, and summarized potential therapies based on previous findings.

Targeting Dual Immune Checkpoints PD-L1 and HLA-G by Trispecific T Cell Engager for Treating Heterogeneous Lung Cancer

Immunotherapy targeting immune checkpoints (ICPs), such as programmed death-ligand-1 (PD-L1), is used as a treatment option for advanced or metastatic non-small cell lung cancer (NSCLC). However, overall response rate to anti-PD-L1 treatment is limited due to antigen heterogeneity and the immune-suppressive tumor microenvironment. Human leukocyte antigen-G (HLA-G), an ICP as well as a neoexpressed tumor-associated antigen, is previously demonstrated to be a beneficial target in combination with anti-PD-L1. In this study, a nanobody-based trispecific T cell engager (Nb-TriTE) is developed, capable of simultaneously binding to T cells, macrophages, and cancer cells while redirecting T cells toward tumor cells expressing PD-L1- and/or HLA-G. Nb-TriTE shows broad spectrum anti-tumor effects in vitro by augmenting cytotoxicity mediated by human peripheral blood mononuclear cells (PBMCs). In a humanized immunodeficient murine NSCLC model, Nb-TriTE exhibits superior anti-cancer potency compared to monoclonal antibodies and bispecific T cell engagers. Nb-TriTE, at the dose with pharmacoactivity, does not induce additional enhancement of circulating cytokines secretion from PMBCs. Nb-TriTE effectively prolongs the survival of mice without obvious adverse events. In conclusion, this study introduces an innovative therapeutic approach to address the challenges of immunotherapy and the tumor microenvironment in NSCLC through utilizing the dual ICP-targeting Nb-TriTE.

LSD1 inhibition attenuates targeted therapy-induced lineage plasticity in BRAF V600E colorectal cancer

BRAF activating mutations occur in approximately 10% of metastatic colorectal cancer (CRCs) and are associated with worse prognosis due to an inferior response to standard chemotherapy. Standard of care for patients with refractory metastatic BRAF V600E CRC is treatment with BRAF and EGFR inhibitors. However, responses are not durable. Lineage plasticity to neuroendocrine cancer is an emerging mechanism of targeted therapy resistance in several cancer types. Enteroendocrine cells (EECs), the neuroendocrine cell of the intestine, are uniquely present in BRAF V600E CRC as compared to BRAF wildtype CRC. Here, we demonstrated that combined BRAF and EGFR inhibition enriches for EECs in several models of BRAF V600E CRC. Additionally, EECs and other secretory cell types were enriched in a subset of BRAF V600E CRC patient samples following targeted therapy. Importantly, inhibition of the lysine demethylase LSD1 with a clinically relevant inhibitor attenuated targeted therapy-induced EEC enrichment through blocking the interaction of LSD1, CoREST2 and STAT3.

Statement of Significance

Our findings that BRAF plus EGFR inhibition induces lineage plasticity in BRAF V600E CRC represents a new paradigm for how resistance to BRAF plus EGFR inhibition occurs and our finding that LSD1 inhibition blocks lineage plasticity has the potential to improve responses to BRAF plus EGFR inhibitor therapy in patients.

Fibroin nanodisruptor with Ferroptosis-Autophagy synergism is potent for lung cancer treatment

Chemotherapy agents for lung cancer often cause apoptotic resistance in cells, leading to suboptimal therapeutic outcomes. FIN56 can be a potential treatment for lung cancer as it induces non-apoptotic cell death, namely ferroptosis. However, a bottleneck exists in FIN56-induced ferroptosis treatment; specifically, FIN56 fails to induce sufficient oxidative stress and may even trigger the defense system against ferroptosis, resulting in poor therapeutic efficacy. To overcome this, this study proposed a strategy of co-delivering FIN56 and piperlongumine to enhance the ferroptosis treatment effect by increasing oxidative stress and connecting with the autophagy pathway. FIN56 and piperlongumine were encapsulated into silk fibroin-based nano-disruptors, named FP@SFN. Characterization results showed that the particle size of FP@SFN was in the nanometer range and the distribution was uniform. Both in vivo and in vitro studies demonstrated that FP@SFN could effectively eliminate A549 cells and inhibit subcutaneous lung cancer tumors. Notably, ferroptosis and autophagy were identified as the main cell death pathways through which the nano-disruptors increased oxidative stress and facilitated cell membrane rupture. In conclusion, nano-disruptors can effectively enhance the therapeutic effect of ferroptosis treatment for lung cancer through the ferroptosis-autophagy synergy mechanism, providing a reference for the development of related therapeutics.

Sarcomatoid carcinoma transformation in oral undifferentiated carcinoma following sequential immune combined targeted therapy: a case report

The diagnosis and treatment of head and neck undifferentiated carcinoma (HNUC) present significant challenges. Herein, we present the case of a patient with advanced HNUC who underwent conversion surgery following treatment with a combination of pembrolizumab and nimotuzumab. During therapy, histological transformation from undifferentiated to sarcomatoid carcinoma was detected at the primary site. This case not only highlights the potential of immune combination-targeted therapy to reduce tumour burden and increase the surgical options for patients, but also reveals the complex alterations in tumour biology that may occur during treatment. It emphasizes the necessity for routine pathological assessments throughout the therapeutic regimen to guide personalised therapeutic strategies and optimise patient prognoses.

Peptide-Conjugated Vascular Endothelial Extracellular Vesicles Encapsulating Vinorelbine for Lung Cancer Targeted Therapeutics

Lung cancer is one of the major cancer types and poses challenges in its treatment, including lack of specificity and harm to healthy cells. Nanoparticle-based drug delivery systems (NDDSs) show promise in overcoming these challenges. While conventional NDDSs have drawbacks, such as immune response and capture by the reticuloendothelial system (RES), extracellular vesicles (EVs) present a potential solution. EVs, which are naturally released from cells, can evade the RES without surface modification and with minimal toxicity to healthy cells. This makes them a promising candidate for developing a lung-cancer-targeting drug delivery system. EVs isolated from vascular endothelial cells, such as human umbilical endothelial-cell-derived EVs (HUVEC-EVs), have shown anti-angiogenic activity in a lung cancer mouse model; therefore, in this study, HUVEC-EVs were chosen as a carrier for drug delivery. To achieve lung-cancer-specific targeting, HUVEC-EVs were engineered to be decorated with GE11 peptides (GE11-HUVEC-EVs) via a postinsertional technique to target the epidermal growth factor receptor (EGFR) that is overexpressed on the surface of lung cancer cells. The GE11-HUVEC-EVs were loaded with vinorelbine (GE11-HUVEC-EVs-Vin), and then characterized and evaluated in in vitro and in vivo lung cancer models. Further, we examined the binding affinity of ABCB1, encoding P-glycoprotein, which plays a crucial role in chemoresistance via the efflux of the drug. Our results indicate that GE11-HUVEC-EVs-Vin effectively showed tumoricidal effects against cell and mouse models of lung cancer.

Transcriptomic Heterogeneity of EGFR-Mutant Non-Small Cell Lung Cancer Evolution Toward Small-Cell Lung Cancer

PURPOSE

Histologic transformation from EGFR-mutant non-small cell lung cancer (NSCLC) to small-cell lung cancer (SCLC) is a key mechanism of resistance to EGFR tyrosine kinase inhibitors (TKI). However, transcriptomic changes between NSCLC and transformed SCLC (t-SCLC) remain unexplored.

EXPERIMENTAL DESIGN

We conducted whole-transcriptome analysis of 59 regions of interest through the spatial profiling of formalin-fixed, paraffin-embedded tissues obtained from 10 patients (lung adenocarcinoma, 22; combined SCLC/NSCLC, 7; and t-SCLC, 30 regions of interests). Transcriptomic profiles and differentially expressed genes were compared between pre- and post-transformed tumors.

RESULTS

Following EGFR-TKI treatment, 93.7% (15/16) of t-SCLC components evolved into neuroendocrine-high subtypes (SCLC-A or SCLC-N). The transition to t-SCLC occurred regardless of EGFR-TKI treatment and EGFR mutational status, with a notable decrease in EGFR expression (P < 0.001) at both mRNA and protein levels. Pathway analysis revealed that gene overexpression was related to epigenetic alterations in t-SCLC. Interestingly, histone deacetylase inhibitors restored EGFR expression in SNU-2962A cells and their organoid model. The synergistic effects of third-generation EGFR-TKI osimertinib and the histone deacetylase inhibitor fimepinostat were validated in both in vitro and in vivo models.

CONCLUSIONS

Our study demonstrated that most t-SCLC cases showed neuronal subtypes with low EGFR expression. Differentially expressed gene analysis and t-SCLC preclinical models identified an epigenetic modifier as a promising treatment strategy for t-SCLC.