Overcoming tyrosine kinase inhibitor resistance in lung cancer brain metastasis with CTLA4 blockade

The fibroinflammatory response in cancer

Fibroinflammation refers to the highly integrated fibrogenic and inflammatory responses mediated by the concerted function of fibroblasts and innate immune cells in response to tissue perturbation. This process underlies the desmoplastic remodelling of the tumour microenvironment and thus plays an important role in tumour initiation, growth and metastasis. More specifically, fibroinflammation alters the biochemical and biomechanical signalling in malignant cells to promote their proliferation and survival and further supports an immunosuppressive microenvironment by polarizing the immune status of tumours. Additionally, the presence of fibroinflammation is often associated with therapeutic resistance. As such, there is increasing interest in targeting this process to normalize the tumour microenvironment and thus enhance the treatment of solid tumours. Herein, we review advances made in unravelling the complexity of cancer-associated fibroinflammation that can inform the rational design of therapies targeting this.

Refining Lung Cancer Brain Metastasis Models for Spatiotemporal Dynamic Research and Personalized Therapy

Lung cancer brain metastasis (LCBM) is a major contributor to cancer-related mortality, with a median survival of 8-16 months following diagnosis, despite advances in therapeutic strategies. The development of clinically relevant animal models is crucial for understanding the metastatic cascade and assessing therapies that can penetrate the blood-brain barrier (BBB). This review critically evaluates five primary LCBM modeling approaches-orthotopic implantation, intracardiac injection, stereotactic intracranial injection, carotid artery injection, and tail vein injection-focusing on their clinical applicability. We systematically compare their ability to replicate human metastatic pathophysiology and highlight emerging technologies for personalized therapy screening. Additionally, we analyze breakthrough strategies in central nervous system (CNS)-targeted drug delivery, including microparticle targeted delivery systems designed to enhance brain accumulation. By incorporating advances in single-cell omics and AI-driven metastasis prediction, this work provides a roadmap for the next generation of LCBM models, aimed at bridging preclinical and clinical research.

Targeting immune checkpoints in hepatocellular carcinoma therapy: toward combination strategies with curative potential

Hepatocellular carcinoma (HCC) is a primary liver cancer characterized by poor immune cell infiltration and a strongly immunosuppressive microenvironment. Traditional treatments have often yielded unsatisfactory outcomes due to the insidious onset of the disease. Encouragingly, the introduction of immune checkpoint inhibitors (ICIs) has significantly transformed the approach to HCC treatment. Moreover, combining ICIs with other therapies or novel materials is considered the most promising opportunity in HCC, with some of these combinations already being evaluated in large-scale clinical trials. Unfortunately, most clinical trials fail to meet their endpoints, and the few successful ones also face challenges. This indicates that the potential of ICIs in HCC treatment remains underutilized, prompting a reevaluation of this promising therapy. Therefore, this article provides a review of the role of immune checkpoints in cancer treatment, the research progress of ICIs and their combination application in the treatment of HCC, aiming to open up avenues for the development of safer and more efficient immune checkpoint-related strategies for HCC treatment.

Strategies Beyond 3rd EGFR-TKI Acquired Resistance: Opportunities and Challenges

The seminal identification of epidermal growth factor receptor (EGFR) mutations as pivotal oncogenic drivers in non-small cell lung cancer (NSCLC) has catalyzed the evolution of biomarker-guided therapeutic paradigms for advanced disease. Currently, third-generation EGFR tyrosine kinase inhibitors (EGFR-TKI) have revolutionized first-line treatment for advanced EGFR-mutated NSCLC, yet acquired resistance remains an inevitable and formidable clinical challenge. This review systematically summarizes molecular mechanisms underlying treatment resistance, with a focus on clinical challenges associated with central nervous system (CNS) metastases. Therapeutic resistance mechanisms are categorized into EGFR-dependent (on-target) pathways, typified by acquired kinase domain mutations (e.g., C797S), and EGFR-independent (off-target) pathways, involving compensatory activation of parallel signaling effectors (e.g., MET amplification, HER2 activation) or phenotypic transformation. We further evaluated contemporary diagnostic modalities for identifying resistance drivers and appraised emerging therapeutic strategies, including fourth-generation EGFR-TKI, various combination therapies, and antibody-drug conjugates (ADCs), and so forth, with emphasis on ongoing clinical trials that may transform the existing treatment paradigm. By synthesizing preclinical and clinical insights, this review aims to advance mechanistic understanding and propose therapeutic strategies to overcome acquired resistance to third-generation EGFR-TKI in first-line treatment.

Single-cell profiling uncovers the intricate pathological niche diversity in brain, lymph node, bone, and adrenal metastases of lung cancer

PURPOSE

The aim of this study is to explore the pathological niche of cancer metastasis and the site-specific interactions between tumor cells and the microenvironment, understand the mechanisms driving metastasis progression and identify potential therapeutic targets.

METHODS

Data from four lung cancer metastasis datasets (GSE123902, GSE131907, GSE148071, and GSE186344) were downloaded and subjected to stringent quality control and filtering. Cell types were identified using canonical markers, and pseudotime trajectory analysis was performed to evaluate cell differentiation. Functional and pathway enrichment analyses, including ssGSEA and GO/KEGG, were conducted. CellphoneDB was used to analyze intercellular communication, ranking receptor-ligand interactions based on communication strength.

RESULTS

Eleven cell types were identified after quality control, revealing significant heterogeneity and site-specific functionality in lung cancer metastases. CTLs showed notable activity in antigen presentation and T-cell differentiation pathways, with DNAJB1⁺ CTLs playing a dominant role in cytotoxicity and immune regulation. B cells, myeloid cells, and CAFs were involved in immune modulation, defense, and matrix remodeling through specific signaling pathways. Tumor cell subclusters drove proliferation, migration, and immune evasion via immune-regulatory, Hippo, and TGF-beta pathways. No overlapping pathways were observed across metastatic sites. Cell communication analysis identified PPIA-BSG and APP-CD74 as key axes in brain and lymph node metastases, while FN1-Integrin and CTLA4-CD86 dominated in bone and adrenal metastases, respectively.

CONCLUSIONS

In summary, this study highlights the functional heterogeneity and site-specific interactions of cells in lung cancer metastases, providing insights into the mechanisms shaping metastatic niches and potential therapeutic strategies.

Cancer brain metastasis: molecular mechanisms and therapeutic strategies

Brain metastases (BMs) are the most common intracranial tumors in adults and the major cause of cancer-related morbidity and mortality. The occurrence of BMs varies according to the type of primary tumors with most frequence in lung cancer, melanoma and breast cancer. Among of them, lung cancer has been reported to have a higher risk of BMs than other types of cancers with 40 ~ 50% of such patients will develop BMs during the course of disease. BMs lead to many neurological complications and result in a poor quality of life and short life span. Although the treatment strategies were improved for brain tumors in the past decades, the prognosis of BMs patients is grim. Poorly understanding of the molecular and cellular characteristics of BMs and the complicated interaction with brain microenvironment are the major reasons for the dismal prognosis of BM patients. Recent studies have enhanced understanding of the mechanisms of BMs. The newly identified potential therapeutic targets and the advanced therapeutic strategies have brought light for a better cure of BMs. In this review, we summarized the mechanisms of BMs during the metastatic course, the molecular and cellular landscapes of BMs, and the advances of novel drug delivery systems for overcoming the obstruction of blood-brain barrier (BBB). We further discussed the challenges of the emerging therapeutic strategies, such as synergistic approach of combining targeted therapy with immunotherapy, which will provide vital clues for realizing the precise and personalized medicine for BM patients in the future.

Single-Cell RNA Sequencing in Unraveling Acquired Resistance to EGFR-TKIs in Non-Small Cell Lung Cancer: New Perspectives

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have demonstrated remarkable efficacy in treating non-small cell lung cancer (NSCLC), but acquired resistance greatly reduces efficacy and poses a significant challenge to patients. While numerous studies have investigated the mechanisms underlying EGFR-TKI resistance, its complexity and diversity make the existing understanding still incomplete. Traditional approaches frequently struggle to adequately reveal the process of drug resistance development through mean value analysis at the overall cellular level. In recent years, the rapid development of single-cell RNA sequencing technology has introduced a transformative method for analyzing gene expression changes within tumor cells at a single-cell resolution. It not only deepens our understanding of the tumor microenvironment and cellular heterogeneity associated with EGFR-TKI resistance but also identifies potential biomarkers of resistance. In this review, we highlight the critical role of single-cell RNA sequencing in lung cancer research, with a particular focus on its application to exploring the mechanisms of EGFR-TKI-acquired resistance in NSCLC. We emphasize its potential for elucidating the complexity of drug resistance mechanism and its promise in informing more precise and personalized treatment strategies. Ultimately, this approach aims to advance NSCLC treatment toward a new era of precision medicine.

Comprehensive review of signaling pathways and therapeutic targets in gastrointestinal cancers

Targeted therapy, the milestone in the development of human medicine, originated in 2004 when the FDA approved the first targeted agent bevacizumab for colorectal cancer treatment. This new development has resulted from drug developers moving beyond traditional chemotherapy, and several trials have popped up in the last two decades with an unprecedented speed. Specifically, EGF/EGFR, VEGF/VEGFR, HGF/c-MET, and Claudin 18.2 therapeutic targets have been developed in recent years. Some targets previously thought to be undruggable are now being newly explored, such as the RAS site. However, the efficacy of targeted therapy is extremely variable, especially with the emergence of new drugs and the innovative use of traditional targets for other tumors in recent years. Accordingly, this review provides an overview of the major signaling pathway mechanisms and recent advances in targeted therapy for gastrointestinal cancers, as well as future perspectives.

CD146 promotes resistance of NSCLC brain metastases to pemetrexed via the NF-κB signaling pathway

Introduction

Pemetrexed is a first line drug for brain metastases from lung cancer, either as monotherapy or combined with other drugs. The frequent occurrence of initial and acquired resistance to pemetrexed results in limited treatment effectiveness in brain metastases. CD146 was recently found to play important roles in chemoresistance and tumor progression. However, the underlying mechanisms of CD146's effects in pemetrexed resistance remain undefined.

Method and results

Sensitivity to pemetrexed was assessed with a preclinical brain metastasis (BM) model based on lung adenocarcinoma PC9 cells. The role and mechanism of CD146 in pemetrexed resistance in non-small cell lung cancer (NSCLC) brain metastasis were explored in vitro and in vivo. A subpopulation of brain metastatic cells derived from progenitor PC9 cells (PC9-BrMS) was significantly resistant to pemetrexed. CD146 levels were significantly increased in pemetrexed resistant brain metastases, while CD146 inhibition suppressed pemetrexed resistance in BM cells. Mechanistically, CD146 mediated pemetrexed resistance in brain metastatic cells by promoting DNA damage repair, maintaining normal cell cycle progression, and regulating the NF-KB pathway to counter apoptosis, and these effects was based on increased DNA damage, cell cycle arrest, and occurrence of apoptosis after CD146 inhibition as well as the reemergence of pemetrexed resistance after CD146 restoration.

Discussion

In summary, this study revealed that the resistance of NSCLC brain metastatic cells to PEM was dependent on CD146.Thus CD146 might be targeted in clinic to overcome pemetrexed resistance in brain metastases from NSCLC.

Mechanisms of Low MHC I Expression and Strategies for Targeting MHC I with Small Molecules in Cancer Immunotherapy

Major histocompatibility complex (MHC) class I load antigens and present them on the cell surface, which transduces the tumor-associated antigens to CD8+ T cells, activating the acquired immune system. However, many tumors downregulate MHC I expression to evade immune surveillance. The low expression of MHC I not only reduce recognition by- and cytotoxicity of CD8+ T cells, but also seriously weakens the anti-tumor effect of immunotherapy by restoring CD8+ T cells, such as immune checkpoint inhibitors (ICIs). Accumulated evidence suggested that restoring MHC I expression is an effective strategy for enhancing tumor immunotherapy. This review focuses on mechanisms underlying MHC I downregulation include gene deletion and mutation, transcriptional inhibition, reduced mRNA stability, increased protein degradation, and disruption of endocytic trafficking. We also provide a comprehensive review of small molecules that restore or upregulate MHC I expression, as well as clinical trials involving the combination of ICIs and these small molecule drugs.

TKI resistance in brain metastasis: A CTLA4 state of mind

Resistance to tyrosine kinase inhibitors (TKIs) in lung cancer brain metastasis (LCBM) remains a clinical challenge. Recently in Cancer Cell, Fu et al. reveal how TKIs reshape the immune microenvironment of LCBM and propose CTLA4 blockade as a promising strategy to overcome resistance.