Three subtypes of lung cancer fibroblasts define distinct therapeutic paradigms

Apoptosis inhibition reprograms alveolar myofibroblasts toward ductal myofibroblasts

The epithelial tree of the lung is shaped proximo-distally by airway smooth muscle cells (ASMCs), ductal myofibroblasts (DMFs), and, transiently, alveolar myofibroblasts (AMFs). Lineage tracing and snapshot imaging suggest the clearance of AMFs via apoptosis post-alveologenesis, although definitive evidence is lacking. Here, we generate an inducible BCL2 overexpression mouse allele to inhibit AMF apoptosis. Using three independent Cre drivers and single-cell RNA-seq, we show that BCL2-rescued AMFs persist around distal alveolar ducts and alveoli and, unexpectedly, mature toward DMFs. Both normal DMFs and rescued DMF-like cells upregulate contractile proteins in a house dust mite-induced asthma model. Our findings demonstrate the apoptotic clearance of AMFs, as well as fate plasticity and pathophysiological convergence of lung mesenchymal cells of the epithelial axis.

Macrophages and fibroblasts as regulators of the immune response in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the few cancers that has yet to benefit from immunotherapies. This is primarily a result of its characteristic 'cold' tumor microenvironment composed of cancer-associated fibroblasts (CAFs), a dense network of extracellular matrix and several immune cell types, the most abundant of which are the tumor-associated macrophages (TAMs). Advances in single-cell and spatial technologies have elucidated the vast functional heterogeneity of CAFs and TAMs, their symbiotic relationship and their cooperative role in the tumor microenvironment. In this Review, we provide an overview of the heterogeneity of CAFs and TAMs, how they establish an immunosuppressive microenvironment and their collaboration in the remodeling of the extracellular matrix. Finally, we examine why the impact of immunotherapy in PDAC has been limited and how a detailed molecular and spatial understanding of the combined role of CAFs and TAMs is paramount to the design of effective therapies.

Characterization of cancer-associated fibroblasts and their spatial architecture reveals heterogeneity and survival associations in classic Hodgkin lymphoma

Cancer-associated fibroblasts (CAFs) are a heterogeneous population of stromal cells, which modulate the immune system and can have both pro- and anti-tumorigenic effects. In classic Hodgkin lymphoma (cHL), the role of CAFs has remained largely undefined. We applied multiplexed immunofluorescence imaging and spatial analysis on tumor samples from two independent cHL patient cohorts (n = 131 and n = 148) to study CAFs and their interactions with Hodgkin Reed-Sternberg (HRS) and tumor microenvironment (TME) cells at the single-cell resolution. We show that higher proportions of CAFs are associated with favorable outcomes, independent of the clinical covariables. In contrast, a subset of CD45+ immune cells with strong fibroblast-activation protein positivity, classified as macrophages, was less abundant in nodular sclerosis subtype and associated with worse outcomes. Neighborhood analysis allowed for the identification of colocalization or regional exclusion of phenotypically defined cell types and recurrent cellular neighborhoods. Despite the positive impact of CAF proportions on survival, patients with enrichment of platelet-derived growth factor receptor beta (PDGFRB)-positive CAFs in the vicinity of HRS cells had worse survival in both cohorts, independent of the clinical determinants. Our findings distinguish various subsets of CAFs and macrophages impacting survival in cHL and underscore the importance of the spatial arrangements in the TME.

Cancer-associated fibroblasts promote EGFR-TKI resistance via the CTHRC1/glycolysis/H3K18la positive feedback loop

Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) remains a major challenge in the treatment of lung cancer. Cancer associated fibroblasts (CAFs) play a key role in promoting resistance to anti-cancer therapies. This study identified a subpopulation of CAFs characterized by the overexpression of collagen triple helix repeat-containing 1 (CTHRC1) through single-cell RNA sequencing of lung cancer patients undergoing EGFR-TKI treatment. These CTHRC1+ CAFs were enriched in drug-resistant tumors. Mechanistically, CTHRC1+ CAFs enhance the glycolytic activity of cancer cells by activating the TGF-β/Smad3 signaling pathway. Excess lactate produced in the process of glycolysis further upregulates CTHRC1 expression in CAFs through histone lactylation, creating a positive feedback loop that sustains EGFR-TKI resistance. The study also demonstrated that Gambogenic Acid, a natural compound, can disrupt this feedback loop, thereby improving the efficacy of EGFR-TKI therapy. Additionally, the presence of CTHRC1+ CAFs in tumor tissues could serve as a biomarker for predicting the response to EGFR-TKI therapy and patient prognosis. Overall, this study highlights the significant role of CAFs in EGFR-TKI resistance and suggests that targeting CTHRC1+ CAFs could be a promising strategy to overcome drug resistance in lung cancer.

ALK in cancer: from function to therapeutic targeting

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase (RTK) that acts as an oncogenic driver in solid and haematological malignancies in both children and adults. Although ALK-expressing (ALK+) tumours show strong initial responses to the series of ALK inhibitors currently available, many patients will develop resistance. In this Review, we discuss recent advances in ALK oncogenic signalling, together with existing and promising new modalities to treat ALK-driven tumours, including currently approved ALK-directed therapies, namely tyrosine kinase inhibitors, and novel approaches such as ALK-specific immune therapies. Although ALK inhibitors have changed the management and clinical history of ALK+ tumours, they are still insufficient to cure most of the patients. Therefore, more effort is needed to further improve outcomes and prevent the tumour resistance, recurrence and metastatic spread that many patients with ALK+ tumours experience. Here, we outline how a multipronged approach directed against ALK and other essential pathways that sustain the persistence of ALK+ tumours, together with potent or specific immunotherapies, could achieve this goal. We envision that the lessons learned from treating ALK+ tumours in the clinic could ultimately accelerate the implementation of innovative combination therapies to treat tumours driven by other tyrosine kinases or oncogenes with similar properties.

Multifactorial stroma-mediated resistance is a major contributor to residual disease under targeted therapies in lung cancers

Despite inducing strong and durable clinical responses, targeted therapies do not eliminate advanced cancers, as a subset of tumor cells survives within residual tumors, eventually developing resistance. The ability of tumor cells to avoid therapeutic elimination can be mediated both by cell-intrinsic and microenvironmental mechanisms. Whilst the specific molecular mediators of cell-intrinsic and microenvironmental resistance are well understood, their relative contribution to in vivo therapeutic responses remains poorly defined. Using spatial histological inferences from experimental models of ALK+ NSCLC, we found that peristromal niches protected tumor cells from therapeutic elimination in vivo, enabling in vivo persistence. Whereas the development of bona fide resistance is associated with the development of the development of cell-intrinsic resistance, relapse of tumor growth reflects a combined effect of both cell-intrinsic and microenvironmental mechanisms. Mechanistically, the protective effect of the peristromal niche is not reducible to a single mechanism, instead reflecting a combined effect of multiple juxtacrine and paracrine mediators. The lack of reducibility to a single molecular mediator presents an obvious challenge to the therapeutic paradigms of targeting individual resistance mechanisms. We found that this challenge could be mitigated by shifting the therapeutic focus to orthogonal collateral sensitivities of residual tumors. Exploiting adaptive upregulation of HER2, associated with both cell-intrinsic and microenvironmental persistence, using the antibody-drug conjugate T-DXd strongly enhanced the effect of targeted therapies and suppressed the development of resistance.

Using Cancer-Associated Fibroblasts as a Shear-Wave Elastography Imaging Biomarker to Predict Anti-PD-1 Efficacy of Triple-Negative Breast Cancer

In the clinical setting, the efficacy of single-agent immune checkpoint inhibitors (ICIs) in triple-negative breast cancer (TNBC) remains suboptimal. Therefore, there is a pressing need to develop predictive biomarkers to identify non-responders. Considering that cancer-associated fibroblasts (CAFs) represent an integral component of the tumor microenvironment that affects the stiffness of solid tumors on shear-wave elastography (SWE) imaging, wound healing CAFs (WH CAFs) were identified in highly heterogeneous TNBC. This subtype highly expressed vitronectin (VTN) and constituted the majority of CAFs. Moreover, WH CAFs were negatively correlated with CD8+ T cell infiltration levels and influenced tumor proliferation in the Eo771 mouse model. Furthermore, multi-omics analysis validated its role in immunosuppression. In order to non-invasively classify patients as responders or non-responders to ICI monotherapy, a deep learning model was constructed to classify the level of WH CAFs based on SWE imaging. As anticipated, this model effectively distinguished the level of WH CAFs in tumors. Based on the classification of the level of WH CAFs, while tumors with a high level of WH CAFs were found to exhibit a poor response to anti programmed cell death protein 1 (PD-1) monotherapy, they were responsive to the combination of anti-PD-1 and erdafitinib, a selective fibroblast growth factor receptor (FGFR) inhibitor. Overall, these findings establish a reference for a novel non-invasive method for predicting ICI efficacy to guide the selection of TNBC patients for precision treatment in clinical settings.

Benign non-immune cells in tumor microenvironment

The tumor microenvironment (TME) is a highly complex and continuous evolving ecosystem, consisting of a diverse array of cellular and non-cellular components. Among these, benign non-immune cells, including cancer-associated fibroblasts (CAFs), adipocytes, endothelial cells (ECs), pericytes (PCs), Schwann cells (SCs) and others, are crucial factors for tumor development. Benign non-immune cells within the TME interact with both tumor cells and immune cells. These interactions contribute to tumor progression through both direct contact and indirect communication. Numerous studies have highlighted the role that benign non-immune cells exert on tumor progression and potential tumor-promoting mechanisms via multiple signaling pathways and factors. However, these benign non-immune cells may play different roles across cancer types. Therefore, it is important to understand the potential roles of benign non-immune cells within the TME based on tumor heterogeneity. A deep understanding allows us to develop novel cancer therapies by targeting these cells. In this review, we will introduce several types of benign non-immune cells that exert on different cancer types according to tumor heterogeneity and their roles in the TME.

PI3 expression predicts recurrence after chemotherapy with DNA-damaging drugs in gastric cancer

Despite recent advances in gastric cancer therapy, chemotherapy resistance and lack of methods for selecting combination regimens remain major problems. Organoids, which provide a culture system that more closely resembles tumor cell organization than traditional cell lines, can be established from surgical specimens with a high success rate and are widely used for drug sensitivity assays. In this study, we aimed to identify a novel biomarker for predicting multidrug resistance using gastric cancer organoids (GCOs). We evaluated 5-fluorouracil or oxaliplatin-resistant GCOs to find novel biomarkers that reflect multidrug resistance in gastric cancer. To examine the resistance mechanisms, RNA-sequencing analysis and ex vivo drug sensitivity testing were performed. The association of biomarkers with patient prognosis and chemotherapy efficacy was evaluated using three original cohorts with a total of 230 cases. The results were also validated with two independent public cohorts and single-cell RNA sequence data. Increased expression of peptidase inhibitor 3 (PI3) was detected in all 5-fluorouracil or oxaliplatin-resistant GCOs. Our findings suggest a potential association of PI3 expression with ribosome biosynthesis and RNA metabolism under organoid conditions. We also found that PI3 overexpression promoted 5-fluorouracil/oxaliplatin/cisplatin resistance but not paclitaxel resistance. Immunohistochemical evaluation of PI3 expression revealed that the PI3-positive gastric cancer group had a poorer outcome, especially in terms of time to recurrence. PI3 positivity was also an independent predictor of relapse after chemotherapy with DNA-damaging agents. PI3 promotes DNA-damaging drug resistance through multiple downstream regulations related to RNA and ribosomal metabolism. PI3 may be useful as a biomarker for the therapeutic selection of non-DNA-damaging agents. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Cancer-Associated Fibroblasts as the "Architect" of the Lung Cancer Immune Microenvironment: Multidimensional Roles and Synergistic Regulation with Radiotherapy

Cancer-associated fibroblasts (CAFs), as the "architect" of the immune microenvironment in lung cancer, play a multidimensional role in tumor progression and immune regulation. In this review, we summarize the heterogeneity of the origin and the molecular phenotype of CAFs in lung cancer, and explore the complex interactions between CAFs and multiple components of the tumor microenvironment, including the regulatory relationships with innate immune cells (e.g., tumor-associated macrophages, tumor-associated neutrophils), adaptive immune cells (e.g., T cells), and extracellular matrix (ECM). CAFs significantly influence tumor progression and immunomodulation through the secretion of cytokines, remodeling of the ECM, and the regulation of immune cell function significantly affects the immune escape and treatment resistance of tumors. In addition, this review also deeply explored the synergistic regulatory relationship between CAF and radiotherapy, revealing the key role of CAF in radiotherapy-induced remodeling of the immune microenvironment, which provides a new perspective for optimizing the comprehensive treatment strategy of lung cancer. By comprehensively analyzing the multidimensional roles of CAF and its interaction with radiotherapy, this review aims to provide a theoretical basis for the precise regulation of the immune microenvironment and clinical treatment of lung cancer.

Phosphorylation of MET Is Upregulated in Metastatic Sites of Renal Cell Carcinoma: Possible Role of MET and Hepatocyte Growth Factor Activation-Targeted Combined Therapy

Background: Increased expression of MET and hepatocyte growth factor (HGF)-related molecules has been positively correlated with poor prognosis in renal cell carcinoma (RCC). In the current study, the expression and phosphorylation of MET in metastatic RCC (mRCC) are determined by immunohistochemistry, and the therapeutic effect of MET and HGF activation-targeting agents for RCC cell lines is analyzed. Methods: Immunohistochemistry was performed for 76 formalin-fixed paraffin-embedded specimens (primary tumor: 32, metastatic site: 44). The therapeutic effect of capmatinib (MET-I) and SRI-31215 (inhibitor of HGF-activating proteases: HGFA-I) was determined based on the inhibition of MET phosphorylation, cell proliferation, and cell migration in 786-O and caki-1 cell lines. Results: Increased expression and phosphorylation of MET were observed in both primary tumor and metastatic sites; however, phosphorylation was significantly upregulated in metastatic sites (p = 0.0001). In an assay of RCC cell lines, the strongest inhibition of MET phosphorylation, cell proliferation, and migration was confirmed with the combined used of MET-I and HGFA-I. Conclusions: Phosphorylation of MET was significantly upregulated in metastasis, which suggested the importance of downregulation in the treatment of mRCC. Our findings suggest that dual inhibition of MET and HGF activation may offer a promising strategy for mRCC treatment, warranting further clinical validation.

Extracellular Vesicles Secreted by Cancer-Associated Fibroblasts Drive Non-Invasive Cancer Cell Progression to Metastasis via TGF-β Signalling Hyperactivation

Metastasis is the leading cause of cancer-related deaths. Cancer-associated fibroblasts (CAFs) are abundant components within the tumour microenvironment, playing critical roles in metastasis. Although increasing evidence supports a role for small extracellular vesicles (sEVs) in this process, their precise contribution and molecular mechanisms remain unclear, compromising the development of antimetastatic therapies. Here, we establish that CAF-sEVs drive metastasis by mediating CAF-cancer cell interaction and hyperactivating TGF-β signalling in tumour cells. Metastasis is abolished by genetically targeting CAF-sEV secretion and consequent reduction of TGF-β signalling in cancer cells. Pharmacological treatment with dimethyl amiloride (DMA) decreases CAFs' sEV secretion, reduces TGF-β signalling levels in tumour cells and abrogates metastasis and tumour self-seeding. This work defines a new mechanism required by CAFs to drive cancer progression, supporting the therapeutic targeting of EV trafficking to disable the driving forces of metastasis.

Solid Predominant Histology and High Podoplanin Expression in Cancer-Associated Fibroblast Predict Primary Resistance to Osimertinib in EGFR-Mutated Lung Adenocarcinoma

Introduction

Resistance to EGFR tyrosine kinase inhibitors is influenced by tumor-intrinsic and -extrinsic factors. We investigated the impact of tumor cell histology and tumor microenvironment on the efficacy of osimertinib.

Methods

We evaluated surgically resected adenocarcinoma from patients treated with first-line osimertinib at the National Cancer Center Hospital East (2016-2023), evaluating clinicopathologic characteristics, tumor cell histology, podoplanin expression in cancer-associated fibroblasts (CAFs) identified by immunohistochemistry, and outcomes. We also investigated HGF mRNA expression levels, using The Cancer Genome Atlas Program and Singapore Oncology Data Portal cohorts.

Results

The study included 93 patients. Solid (n = 19) versus non-solid predominant (n = 74) histology was not associated with worse disease-free survival after surgery (p = 0.12), but was significantly associated with worse progression-free survival (PFS) and overall survival following osimertinib treatment (p = 0.026, p = 0.004). Similarly, high-podoplanin (n = 31) versus low-podoplanin (n = 62) expression in CAFs was not associated with worse disease-free survival after surgery (p = 0.65), but was significantly associated with worse PFS and showed a trend towards worse overall survival following osimertinib treatment (p < 0.001, p = 0.11). In the multivariable analysis, solid predominant histology and high-podoplanin expression in CAFs were independently associated with worse PFS. In the cohorts of The Cancer Genome Atlas Program and Singapore Oncology Data Portal, EGFR-mutated lung adenocarcinoma with solid predominant histology or high-podoplanin expression exhibited significantly higher HGF expression.

Conclusions

Solid predominant histology and high-podoplanin expression in CAFs predicted osimertinib resistance, potentially guiding the selection of patients for more intensive treatments beyond osimertinib monotherapy.

Targeting the Tumor Microenvironment in EGFR-Mutant Lung Cancer: Opportunities and Challenges

Tyrosine kinase inhibitors (TKIs) have transformed the treatment of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer. However, treatment resistance remains a major challenge in clinical practice. The tumor microenvironment (TME) is a complex system composed of tumor cells, immune and non-immune cells, and non-cellular components. Evidence indicates that dynamic changes in TME during TKI treatment are associated with the development of resistance. Research has focused on identifying how each component of the TME interacts with tumors and TKIs to understand therapeutic targets that could address TKI resistance. In this review, we describe how TME components, such as immune cells, fibroblasts, blood vessels, immune checkpoint proteins, and cytokines, interact with EGFR-mutant tumors and how they can promote resistance to TKIs. Furthermore, we discuss potential strategies targeting TME as a novel therapeutic approach.

Promotion Mechanisms of Stromal Cell-Mediated Lung Cancer Development Within Tumor Microenvironment

Lung cancer, with its high incidence and mortality rates, has garnered significant attention in the medical community. The tumor microenvironment (TME), composed of tumor cells, stromal cells, extracellular matrix, surrounding blood vessels, and other signaling molecules, plays a pivotal role in the development of lung cancer. Stromal cells within the TME hold potential as therapeutic targets for lung cancer treatment. However, the precise and comprehensive mechanisms by which stromal cells contribute to lung cancer progression have not been fully elucidated. This review aims to explore the mechanisms through which stromal cells in the tumor microenvironment promote lung cancer development, with a particular focus on how immune cells, tumor-associated fibroblasts, and endothelial cells contribute to immune suppression, inflammation, and angiogenesis. The goal is to provide new insights and potential strategies for the diagnosis and treatment of lung cancer.

Functional heterogeneity of fibroblasts in primary tumors and metastases

Cancer-associated fibroblasts (CAFs) are abundant components of the tumor microenvironment (TME) of most solid malignancies and have emerged as key regulators of cancer progression and therapy response. Although recent technological advances have uncovered substantial CAF molecular heterogeneity at the single-cell level, defining functional roles for most described CAF populations remains challenging. With the aim of bridging CAF molecular and functional heterogeneity, this review focuses on recently identified functional interactions of CAF subtypes with malignant cells, immune cells, and other stromal cells in primary tumors and metastases. Dissecting the heterogeneous functional crosstalk of specific CAF populations with other components is starting to uncover candidate combinatorial strategies for therapeutically targeting the TME and cancer progression.

Combined blockade of GPX4 and activated EGFR/HER3 bypass pathways inhibits the development of ALK-inhibitor-induced tolerant persister cells in ALK-fusion-positive lung cancer

Cancers can develop resistance to treatment with ALK tyrosine kinase inhibitors (ALK-TKIs) via emergence of a subpopulation of drug-tolerant persister (DTP) cells that can survive initial drug treatment long enough to acquire genetic aberrations. DTP cells are thus a potential therapeutic target. We generated alectinib-induced DTP cells from a patient-derived ALK+ non-small-cell lung cancer (NSCLC) cell line and screened 3114 agents in the anticancer compounds library (TargetMol). We identified phospholipid hydroperoxide glutathione peroxidase GPX4 as being involved in promoting the survival of DTP cells. GPX4 was found to be upregulated in DTP cells and to promote cell survival by suppressing reactive oxygen species (ROS) accumulation; GPX4 inhibitors blocked this upregulation and facilitated ROS-mediated cell death. Activated bypass signals involving epidermal growth factor receptor (EGFR)/receptor tyrosine-protein kinase erbB-3 (HER3) were also identified in DTP cells, and co-treatment with EGFR-TKI plus ALK-TKI enhanced ROS levels. Triple combination with an ALK-TKI plus a bypass pathway inhibitor plus a GPX4 inhibitor suppressed cell growth and induced intracellular ROS accumulation more greatly than did treatment with each agent alone. The combined inhibition of ALK plus inhibition of activated bypass signals plus inhibition of GPX4 may be a potent therapeutic strategy for patients with ALK+ NSCLC to prevent the development of resistance to ALK-TKIs and lead to tumor eradication.

Optimizing Osimertinib for NSCLC: Targeting Resistance and Exploring Combination Therapeutics

Non-small-cell lung cancer (NSCLC) is a leading cause of cancer-related deaths worldwide, with epidermal growth factor receptor (EGFR) mutations present in a substantial proportion of patients. Third-generation EGFR tyrosine kinase inhibitors (EGFR TKI), exemplified by osimertinib, have dramatically improved outcomes by effectively targeting the T790M mutation-a primary driver of acquired resistance to earlier-generation EGFR TKI. Despite these successes, resistance to third-generation EGFR TKIs inevitably emerges. Mechanisms include on-target mutations such as C797S, activation of alternative pathways like MET amplification, histologic transformations, and intricate tumor microenvironment (TME) alterations. These resistance pathways are compounded by challenges in tolerability, adverse events, and tumor heterogeneity. In light of these hurdles, this review examines the evolving landscape of combination therapies designed to enhance or prolong the effectiveness of third-generation EGFR TKIs. We explore key strategies that pair osimertinib with radiotherapy, anti-angiogenic agents, immune checkpoint inhibitors, and other molecularly targeted drugs, and we discuss the biological rationale, preclinical evidence, and clinical trial data supporting these approaches. Emphasis is placed on how these combinations may circumvent diverse resistance mechanisms, improve survival, and maintain a favorable safety profile. By integrating the latest findings, this review aims to guide clinicians and researchers toward more individualized and durable treatment options, ultimately enhancing both survival and quality of life for patients with EGFR-mutated NSCLC.

Drug Delivery System Targeting Cancer-Associated Fibroblast for Improving Immunotherapy

Cancer-associated fibroblasts (CAFs) are a heterogeneous population of non-malignant cells that play a crucial role in the tumor microenvironment, increasingly recognized as key contributors to cancer progression, metastasis, and treatment resistance. So, targeting CAFs has always been considered an important part of cancer immunotherapy. However, targeting CAFs to improve the efficacy of tumor therapy is currently a major challenge. Nanomaterials show their unique advantages in the whole process. At present, nanomaterials have achieved significant accomplishments in medical applications, particularly in the field of cancer-targeted therapy, showing enormous potential. It has been confirmed that nanomaterials can not only directly target CAFs, but also interact with the tumor microenvironment (TME) and immune cells to affect tumorigenesis. As for the cancer treatment, nanomaterials could enhance the therapeutic effect in many ways. Therefore, in this review, we first summarized the current understanding of the complex interactions between CAFs and TME, immune cells, and tumor cells. Next, we discussed common nanomaterials in modern medicine and their respective impacts on the TME, CAFs, and interactions with tumors. Finally, we focus on the application of nano drug delivery system targeting CAFs in cancer therapy.

Cancer associated fibroblasts drive epithelial to mesenchymal transition and classical to basal change in pancreatic ductal adenocarcinoma cells with loss of IL-8 expression

Pancreatic ductal adenocarcinoma (PDAC) carries an extremely poor prognosis, in part resulting from cellular heterogeneity that supports overall tumorigenicity. Cancer associated fibroblasts (CAF) are key determinants of PDAC biology and response to systemic therapy. While CAF subtypes have been defined, the effects of patient-specific CAF heterogeneity and plasticity on tumor cell behavior remain unclear. Here, multi-omics was used to characterize the tumor microenvironment (TME) in tumors from patients undergoing curative-intent surgery for PDAC. In these same patients, matched tumor organoid and CAF lines were established to functionally validate the impact of CAFs on the tumor cells. CAFs were found to drive epithelial-mesenchymal transition (EMT) and a switch in tumor cell classificiaton from classical to basal subtype. Furthermore, we identified CAF-specific interleukin 8 (IL-8) as an important modulator of tumor cell subtype. Finally, we defined neighborhood relationships between tumor cell and T cell subsets.

Cancer-associated fibroblasts: heterogeneity, tumorigenicity and therapeutic targets

Cancer, characterized by its immune evasion, active metabolism, and heightened proliferation, comprises both stroma and cells. Although the research has always focused on parenchymal cells, the non-parenchymal components must not be overlooked. Targeting cancer parenchymal cells has proven to be a formidable challenge, yielding limited success on a broad scale. The tumor microenvironment(TME), a critical niche for cancer cell survival, presents a novel way for cancer treatment. Cancer-associated fibroblast (CAF), as a main component of TME, is a dynamically evolving, dual-functioning stromal cell. Furthermore, their biological activities span the entire spectrum of tumor development, metastasis, drug resistance, and prognosis. A thorough understanding of CAFs functions and therapeutic advances holds significant clinical implications. In this review, we underscore the heterogeneity of CAFs by elaborating on their origins, types and function. Most importantly, by elucidating the direct or indirect crosstalk between CAFs and immune cells, the extracellular matrix, and cancer cells, we emphasize the tumorigenicity of CAFs in cancer. Finally, we highlight the challenges encountered in the exploration of CAFs and list targeted therapies for CAF, which have implications for clinical treatment.

Heterogeneity and therapeutic implications of cancer-associated fibroblasts in lung cancer: Recent advances and future perspectives

Lung cancer is a leading cause of cancer-related mortality. The tumor microenvironment is a complex and heterogeneous cellular environment surrounding tumor cells, including cancer-associated fibroblasts (CAFs), blood vessels, immune cells, the extracellular matrix, and various cytokines secreted by cells. CAFs are highly heterogeneous and play crucial roles in lung cancer. This review highlights recent advances in the understanding of CAFs in lung cancer, focusing on their heterogeneity and functions in tumorigenesis, progression, angiogenesis, invasion, metastasis, therapy resistance, tumor immune suppression, and targeted therapy responses. Additionally, we explore the underlying mechanisms and the potential of CAFs as a target in the development of innovative therapies for lung cancer.

Integrating bulk RNA-seq and scRNA-seq analyses revealed the function and clinical value of thrombospondins in colon cancer

Background

Acting as mediators in cell-matrix and cell-cell communication, matricellular proteins play a crucial role in cancer progression. Thrombospondins (TSPs), a type of matricellular glycoproteins, are key regulators in cancer biology with multifaceted roles. Although TSPs have been implicated in anti-tumor immunity and epithelial-mesenchymal transition (EMT) in several malignancies, their specific roles to colon cancer remain elusive. Addressing this knowledge gap is essential, as understanding the function of TSPs in colon cancer could identify new therapeutic targets and prognostic markers.

Methods

Analyzing 1981 samples from 10 high-throughput datasets, including six bulk RNA-seq, three scRNA-seq, and one spatial transcriptome dataset, our study investigated the prognostic relevance, risk stratification value, immune heterogeneity, and cellular origin of TSPs, as well as their influence on cancer-associated fibroblasts (CAFs). Utilizing survival analysis, unsupervised clustering, and functional enrichment, along with multiple correlation analyses of the tumor-microenvironment (TME) via Gene Set Variation Analysis (GSVA), spatial localization, Monocle2, and CellPhoneDB, we provided insights into the clinical and cellular implications of TSPs.

Results

First, we observed significant upregulation of THBS2 and COMP in colon cancer, both of which displayed significant prognostic value. Additionally, we detected a significant positive correlation between TSPs and immune cells, as well as marker genes of EMT. Second, based on TSPs expression, patients were divided into two clusters with distinct prognoses: the high TSPs expression group (TSPs-H) was characterized by pronounced immune and stromal cell infiltration, and notably elevated T-cell exhaustion scores. Subsequently, we found that THBS2 and COMP may be associated with the differentiation of CAFs into pan-iCAFs and pan-dCAFs, which are known for their heightened matrix remodeling activities. Moreover, THBS2 enhanced CAFs communication with vascular endothelial cells and monocyte-macrophages. CAFs expressing THBS2 (THBS2+ CAFs) demonstrated higher scores across multiple signaling pathways, including angiogenic, EMT, Hedgehog, Notch, Wnt, and TGF-β, when compared to THBS2- CAFs. These observations suggest that THBS2 may be associated with stronger pro-carcinogenic activity in CAFs.

Conclusions

This study revealed the crucial role of TSPs and the significant correlation between THBS2 and CAFs interactions in colon cancer progression, providing valuable insights for targeting TSPs to mitigate cancer progression.

In-silico identification and exploration of small molecule coumarin-1,2,3-triazole hybrids as potential EGFR inhibitors for targeting lung cancer

Globally, lung cancer is a significant public health concern due to its role as the leading cause of cancer-related mortalities. The promising target of EGFR for lung cancer treatment has been identified, providing a potential avenue for more effective therapies. The purpose of the study was to design a library of 1843 coumarin-1,2,3-triazole hybrids and screen them based on a designed pharmacophore to identify potential inhibitors targeting EGFR in lung cancer with minimum or no side effects. Pharmacophore-based screening was carried out and 60 hits were obtained. To gain a better understanding of the binding interactions between the compounds and the targeted receptor, molecular docking was conducted on the 60 screened compounds. In-silico ADME and toxicity studies were also conducted to assess the drug-likeness and safety of the identified compounds. The results indicated that coumarin-1,2,3-triazole hybrids COUM-0849, COUM-0935, COUM-0414, COUM-1335, COUM-0276, and COUM-0484 exhibit dock score of - 10.2, - 10.2, - 10.1, - 10.1, - 10, - 10 while reference molecule - 7.9 kcal/mol for EGFR (PDB ID: 4HJO) respectively. The molecular docking and molecular dynamics simulations revealed that the identified compounds formed stable interactions with the active site of EGFR, indicating their potential as inhibitors. The in-silico ADME and toxicity studies showed that the compounds had favorable drug-likeness properties and low toxicity, further supporting their potential as therapeutic agents. Finally, we performed DFT studies on the best-selected ligands to gain further insights into their electronic properties. The findings of this study provide important insights into the potential of coumarin-1,2,3-triazole hybrids as promising EGFR inhibitors for the management of lung cancer.

The Clinical Significance of Cancer-Associated Fibroblasts Classification in Non-Small Cell Lung Cancer

Malignant cells flourish within a specialized environment known as the tumor microenvironment (TME) [...].

Single-cell resolution spatial analysis of antigen-presenting cancer-associated fibroblast niches

Recent studies have identified a unique subtype of cancer-associated fibroblasts (CAFs) termed antigen-presenting CAFs (apCAFs), which remain the least understood CAF subtype. To gain a comprehensive understanding of the origin and function apCAFs, we construct a fibroblast molecular atlas across 14 types of solid tumors. Our integration study unexpectedly reveals two distinct apCAF lineages present in most cancer types: one associated with mesothelial-like cells and the other with fibrocytes. Using a high-resolution single-cell spatial imaging platform, we characterize the spatial niches of these apCAF lineages. We find that mesothelial-like apCAFs are located near cancer cells, while fibrocyte-like apCAFs are associated with tertiary lymphoid structures. Additionally, we discover that both apCAF lineages can up-regulate the secreted protein SPP1, which facilitates primary tumor formation and peritoneal metastasis. Taken together, this study offers an unprecedented resolution in analyzing apCAF lineages and their spatial niches.

Advances and prospects in tumor infiltrating lymphocyte therapy

Tumor-infiltrating lymphocyte (TIL) therapy in adoptive T-cell therapy (ACT) has already caused durable regression in a variety of cancer types due to T-cell persistence, clinical activity, and duration of objective response and safety. TILs are composed of polyclonal effector T-cells specific to heterogenetic tumor antigens, reasonably providing a promising means for tumor therapy. In addition, their expansion in vitro can release them from the suppressive tumor microenvironment. Even though significant advances have been made in the procedure of TIL therapy, from TIL isolation, modification, expansion, and infusion back to the patient to target the tumor, strategy optimization is always ongoing to overcome drawbacks such as a complex process, options for the lineage differentiation status of TILs, and sufficient trafficking of TILs to the tumor. In this review, we summarize the current advances of TIL therapy, raise problem-based optimization strategies, and provide future perspectives on next-generation TIL therapy as a potential avenue for enhancing cell-based immunotherapy.

Intrahepatic IgA complex induces polarization of cancer-associated fibroblasts to matrix phenotypes in the tumor microenvironment of HCC

BACKGROUND AND AIMS

Cancer-associated fibroblasts (CAFs) play key roles in the tumor microenvironment. IgA contributes to inflammation and dismantling antitumor immunity in the human liver. In this study, we aimed to elucidate the effects of the IgA complex on CAFs in Pil Soo Sung the tumor microenvironment of HCC.

APPROACH AND RESULTS

CAF dynamics in HCC tumor microenvironment were analyzed through single-cell RNA sequencing of HCC samples. CAFs isolated from 50 HCC samples were treated with mock or serum-derived IgA dimers in vitro. Progression-free survival of patients with advanced HCC treated with atezolizumab and bevacizumab was significantly longer in those with low serum IgA levels ( p <0.05). Single-cell analysis showed that subcluster proportions in the CAF-fibroblast activation protein-α matrix were significantly increased in patients with high serum IgA levels. Flow cytometry revealed a significant increase in the mean fluorescence intensity of fibroblast activation protein in the CD68 + cells from patients with high serum IgA levels ( p <0.001). We confirmed CD71 (IgA receptor) expression in CAFs, and IgA-treated CAFs exhibited higher programmed death-ligand 1 expression levels than those in mock-treated CAFs ( p <0.05). Coculture with CAFs attenuated the cytotoxic function of activated CD8 + T cells. Interestingly, activated CD8 + T cells cocultured with IgA-treated CAFs exhibited increased programmed death-1 expression levels than those cocultured with mock-treated CAFs ( p <0.05).

CONCLUSIONS

Intrahepatic IgA induced polarization of HCC-CAFs into more malignant matrix phenotypes and attenuates cytotoxic T-cell function. Our study highlighted their potential roles in tumor progression and immune suppression.

The axis of tumor-associated macrophages, extracellular matrix proteins, and cancer-associated fibroblasts in oncogenesis

The extracellular matrix (ECM) is a complex, dynamic network of multiple macromolecules that serve as a crucial structural and physical scaffold for neighboring cells. In the tumor microenvironment (TME), ECM proteins play a significant role in mediating cellular communication between cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs). Revealing the ECM modification of the TME necessitates the intricate signaling cascades that transpire among diverse cell populations and ECM proteins. The advent of single-cell sequencing has enabled the identification and refinement of specific cellular subpopulations, which has substantially enhanced our comprehension of the intricate milieu and given us a high-resolution perspective on the diversity of ECM proteins. However, it is essential to integrate single-cell data and establish a coherent framework. In this regard, we present a comprehensive review of the relationships among ECM, TAMs, and CAFs. This encompasses insights into the ECM proteins released by TAMs and CAFs, signaling integration in the TAM-ECM-CAF axis, and the potential applications and limitations of targeted therapies for CAFs. This review serves as a reliable resource for focused therapeutic strategies while highlighting the crucial role of ECM proteins as intermediates in the TME.

RNA-seq and bulk RNA-seq data analysis of cancer-related fibroblasts (CAF) in LUAD to construct a CAF-based risk signature

Angiogenesis, metastasis, and resistance to therapy are all facilitated by cancer-associated fibroblasts (CAFs). A CAF-based risk signature can be used to predict patients' prognoses for Lung adenocarcinoma (LUAD) based on CAF characteristics. The Gene Expression Omnibus (GEO) database was used to gather signal-cell RNA sequencing (scRNA-seq) data for this investigation. The GEO and TCGA databases were used to gather bulk RNA-seq and microarray data for LUAD. The scRNA-seq data were analyzed using the Seurat R program based on the CAF markers. Our goal was to use differential expression analysis to discover differentially expressed genes (DEGs) across normal and tumor samples in the TCGA dataset. Pearson correlation analysis was utilized to discover prognostic genes related with CAF, followed by univariate Cox regression analysis. Using Lasso regression, a risk signature based on CAF-related prognostic genes was created. A nomogram model was created based on the clinical and pathological aspects. 5 CAF clusters were identified in LUAD, 4 of which were associated with prognosis. From 2811 DEGs, 1002 genes were found to be significantly correlated with CAF clusters, which led to the creation of a risk signature with 8 genes. These 8 genes were primarily connected with 41 pathways, such as antigen paocessing and presentation, apoptosis, and cell cycle. Meanwhile, the risk signature was significantly associated with stromal and immune scores, as well as some immune cells. Multivariate analysis revealed that risk signature was an independent prognostic factor for LUAD, and its value in predicting immunotherapeutic outcomes was confirmed. A novel nomogram integrating the stage and CAF-based risk signature was constructed, which exhibited favorable predictability and reliability in the prognosis prediction of LUAD. CAF-based risk signatures can be effective in predicting the prognosis of LUAD, and they may provide new strategies for cancer treatments by interpreting the response of LUAD to immunotherapy.

Mechanism exploration and model construction for small cell transformation in EGFR-mutant lung adenocarcinomas

Small-cell lung cancer (SCLC) transformation accounts for 3-14% of resistance in EGFR-TKI relapsed lung adenocarcinomas (LUADs), with unknown molecular mechanisms and optimal treatment strategies. We performed transcriptomic analyses (including bulk and spatial transcriptomics) and multiplex immunofluorescence on pre-treated samples from LUADs without transformation after EGFR-TKI treatment (LUAD-NT), primary SCLCs (SCLC-P) and LUADs with transformation after EGFR-TKI treatment (before transformation: LUAD-BT; after transformation: SCLC-AT). Our study found that LUAD-BT exhibited potential transcriptomic characteristics for transformation compared with LUAD-NT. We identified several pathways that shifted during transformation, and the transformation might be promoted by epigenetic alterations (such as HDAC10, HDAC1, DNMT3A) within the tumor cells instead of within the tumor microenvironment. For druggable pathways, transformed-SCLC were proved to be less dependent on EGF signaling but more relied on FGF signaling, while VEGF-VEGFR pathway remained active, indicating potential treatments after transformation. We also found transformed-SCLC showed an immuno-exhausted status which was associated with the duration of EGFR-TKI before transformation. Besides, SCLC-AT exhibited distinct molecular subtypes from SCLC-P. Moreover, we constructed an ideal 4-marker model based on transcriptomic and IHC data to predict SCLC transformation, which obtained a sensitivity of 100% and 87.5%, a specificity of 95.7% and 100% in the training and test cohorts, respectively. We provided insights into the molecular mechanisms of SCLC transformation and the differences between SCLC-AT and SCLC-P, which might shed light on prevention strategies and subsequent therapeutic strategies for SCLC transformation in the future.

Single-cell and spatial omics unravel the spatiotemporal biology of tumour border invasion and haematogenous metastasis

Solid tumours exhibit a well-defined architecture, comprising a differentiated core and a dynamic border that interfaces with the surrounding tissue. This border, characterised by distinct cellular morphology and molecular composition, serves as a critical determinant of the tumour's invasive behaviour. Notably, the invasive border of the primary tumour represents the principal site for intravasation of metastatic cells. These cells, known as circulating tumour cells (CTCs), function as 'seeds' for distant dissemination and display remarkable heterogeneity. Advancements in spatial sequencing technology are progressively unveiling the spatial biological features of tumours. However, systematic investigations specifically targeting the characteristics of the tumour border remain scarce. In this comprehensive review, we illuminate key biological insights along the tumour body-border-haematogenous metastasis axis over the past five years. We delineate the distinctive landscape of tumour invasion boundaries and delve into the intricate heterogeneity and phenotype of CTCs, which orchestrate haematogenous metastasis. These insights have the potential to explain the basis of tumour invasion and distant metastasis, offering new perspectives for the development of more complex and precise clinical interventions and treatments.

Identification and Validation of a Prognostic Signature Based on Fibroblast Immune-related Genes to Predict the Prognosis and Therapeutic Response of renal clear cell carcinoma by Integrated Analysis of Single-Cell and Bulk RNA Sequencing Data

Background: The importance of fibroblasts in cancer progression is becoming more acknowledged, particularly the significance of their immune-related genes. However, the precise roles these genes play in fibroblasts throughout tumor development remains unclear. Exploring how these genes function in advancing kidney renal clear cell carcinoma (KIRC) could provide answers to these uncertainties. Material and method: The Cancer Genome Atlas (TCGA) database served as the source of data for KIRC patients. We distinguished fibroblast immune-related genes (FIGs), which are used to construct risk score. Further analysis conducted including enrichment analysis, assessment of tumor mutation burden (TMB), evaluation of tumor microenvironment (TME), analysis of immune cell infiltration, and drug sensitivity prediction. Result: The risk score using 6 FIGs effectively predicts the outcomes for KIRC patients. Nomogram which is based on the risk score and clinical data, demonstrated superior predictive performance compared to the version without the risk score. Enrichment analysis identified that coagulation pathway predominates in high-risk group, the protein secretion pathway is prevalent in low-risk patients' cohort. The adverse prognosis in high-risk patient cohort could be linked to an elevated TMB. TME analysis showed that high-risk group's tumor tissues contain more immune and stromal cells. Furthermore, the amount of regulatory T cells increases with the risk score. Low-risk group response better to immunotherapy. Finally, RT-qPCR confirmed the differential expression of FIGs in KIRC patients. Conclusion: This risk score and nomogram are valuable tools assessing KIRC patients' prognosis. Poorer prognosis in high-risk categories may have relationship with activation of coagulation pathway and a higher TMB.

3D cell culture models in research: applications to lung cancer pharmacology

Lung cancer remains one of the leading causes of cancer-related mortality worldwide, necessitating innovative research methodologies to improve treatment outcomes and develop novel strategies. The advent of three-dimensional (3D) cell cultures has marked a significant advancement in lung cancer research, offering a more physiologically relevant model compared to traditional two-dimensional (2D) cultures. This review elucidates the various types of 3D cell culture models currently used in lung cancer pharmacology, including spheroids, organoids and engineered tissue models, having pivotal roles in enhancing our understanding of lung cancer biology, facilitating drug development, and advancing precision medicine. 3D cell culture systems mimic the complex spatial architecture and microenvironment of lung tumours, providing critical insights into the cellular and molecular mechanisms of tumour progression, metastasis and drug responses. Spheroids, derived from commercialized cell lines, effectively model the tumour microenvironment (TME), including the formation of hypoxic and nutrient gradients, crucial for evaluating the penetration and efficacy of anti-cancer therapeutics. Organoids and tumouroids, derived from primary tissues, recapitulate the heterogeneity of lung cancers and are instrumental in personalized medicine approaches, supporting the simulation of in vivo pharmacological responses in a patient-specific context. Moreover, these models have been co-cultured with various cell types and biomimicry extracellular matrix (ECM) components to further recapitulate the heterotypic cell-cell and cell-ECM interactions present within the lung TME. 3D cultures have been significantly contributing to the identification of novel therapeutic targets and the understanding of resistance mechanisms against conventional therapies. Therefore, this review summarizes the latest findings in drug research involving lung cancer 3D models, together with the common laboratory-based assays used to study drug effects. Additionally, the integration of 3D cell cultures into lung cancer drug development workflows and precision medicine is discussed. This integration is pivotal in accelerating the translation of laboratory findings into clinical applications, thereby advancing the landscape of lung cancer treatment. By closely mirroring human lung tumours, these models not only enhance our understanding of the disease but also pave the way for the development of more effective and personalized therapeutic strategies.

Cancer-associated fibroblasts: a versatile mediator in tumor progression, metastasis, and targeted therapy

Tumor microenvironment (TME) has been demonstrated to play a significant role in tumor initiation, progression, and metastasis. Cancer-associated fibroblasts (CAFs) are the major component of TME and exhibit heterogeneous properties in their communication with tumor cells. This heterogeneity of CAFs can be attributed to various origins, including quiescent fibroblasts, mesenchymal stem cells (MSCs), adipocytes, pericytes, endothelial cells, and mesothelial cells. Moreover, single-cell RNA sequencing has identified diverse phenotypes of CAFs, with myofibroblastic CAFs (myCAFs) and inflammatory CAFs (iCAFs) being the most acknowledged, alongside newly discovered subtypes like antigen-presenting CAFs (apCAFs). Due to these heterogeneities, CAFs exert multiple functions in tumorigenesis, cancer stemness, angiogenesis, immunosuppression, metabolism, and metastasis. As a result, targeted therapies aimed at the TME, particularly focusing on CAFs, are rapidly developing, fueling the promising future of advanced tumor-targeted therapy.

Molecular and epigenetic ex vivo profiling of testis cancer-associated fibroblasts and their interaction with germ cell tumor cells and macrophages

Germ cell tumors (GCT) are the most common solid tumors in young men of age 15 - 40. In previous studies, we profiled the interaction of GCT cells with cells of the tumor microenvironment (TM), which showed that especially the 3D interaction of fibroblasts (FB) or macrophages with GCT cells influenced the growth behavior and cisplatin response as well as the transcriptome and secretome of the tumor cells, suggesting that the crosstalk of these cells with GCT cells is crucial for tumor progression and therapy outcome. In this study, we shed light on the mechanisms of activation of cancer-associated fibroblasts (CAF) in the GCT setting and their effects on GCT cells lines and the monocyte cell line THP-1. Ex vivo cultures of GCT-derived CAF were established and characterized molecularly and epigenetically by performing DNA methylation arrays, RNA sequencing, and mass spectrometry-based secretome analysis. We demonstrated that the activation state of CAF is influenced by their former prevailing tumor environment in which they have resided. Hereby, we postulate that seminoma (SE) and embryonal carcinoma (EC) activate CAF, while teratoma (TER) play only a minor role in CAF formation. In turn, CAF influence proliferation and the expression of cisplatin sensitivity-related factors in GCT cells lines as well as polarization of in vitro-induced macrophages by the identified effector molecules IGFBP1, LGALS3BP, LYVE1, and PTX3. Our data suggests that the vital interaction of CAF with GCT cells and with macrophages has a huge influence on shaping the extracellular matrix as well as on recruitment of immune cells to the TM. In conclusion, therapeutically interfering with CAF and / or macrophages in addition to the standard therapy might slow-down progression of GCT and re-shaping of the TM to a tumor-promoting environment. Significance: The interaction of CAF with GCT and macrophages considerably influences the microenvironment. Thus, therapeutically interfering with CAF might slow-down progression of GCT and re-shaping of the microenvironment to a tumor-promoting environment.

Targeting therapy-persistent residual disease

Disease relapse driven by acquired drug resistance limits the effectiveness of most systemic anti-cancer agents. Targeting persistent cancer cells in residual disease before relapse has emerged as a potential strategy for enhancing the efficacy and the durability of current therapies. However, barriers remain to implementing persister-directed approaches in the clinic. This Perspective discusses current preclinical and clinical complexities and outlines key steps toward the development of clinical strategies that target therapy-persistent residual disease.

Breast Cancer Stem Cells Upregulate IRF6 in Stromal Fibroblasts to Induce Stromagenesis

The microenvironment of a cancer stem cell (CSC) niche is often found in coexistence with cancer-associated fibroblasts (CAFs). Here, we show the first in-depth analysis of the interaction between primary triple-negative breast cancer stem cells (BCSCs) with fibroblasts. Using 2D co-culture models with specific seeding ratios, we identified stromal fibroblast aggregation at the BCSC cluster periphery, and, on closer observation, the aggregated fibroblasts was found to encircle BCSC clusters in nematic organization. In addition, collagen type I and fibronectin accumulation were also found at the BCSC-stromal periphery. MACE-Seq analysis of BCSC-encapsulating fibroblasts displayed the transformation of stromal fibroblasts to CAFs and the upregulation of fibrosis regulating genes of which the Interferon Regulatory Factor 6 (IRF6) gene was identified. Loss of function experiments with the IRF6 gene decreased fibroblast encapsulation around BCSC clusters in 2D co-cultures. In BCSC xenografts, fibroblast IRF6 expression led to an increase in the stromal area and fibroblast density in tumors, in addition to a reduction in necrotic growth. Based on our findings, we propose that fibroblast IRF6 function is an important factor in the development of the stromal microenvironment and in sustaining the BCSC tumor niche.

Cancer-associated fibroblasts confer ALK inhibitor resistance in EML4-ALK -driven lung cancer via concurrent integrin and MET signaling

Cancer-associated fibroblasts (CAFs) are associated with tumor progression and modulate drug sensitivity of cancer cells. However, the underlying mechanisms are often incompletely understood and crosstalk between tumor cells and CAFs involves soluble secreted as well as adhesion proteins. Interrogating a panel of non-small cell lung cancer (NSCLC) cell lines driven by EML4-ALK fusions, we observed substantial CAF-mediated drug resistance to clinical ALK tyrosine kinase inhibitors (TKIs). Array-based cytokine profiling of fibroblast-derived conditioned- media identified HGF-MET signaling as a major contributor to CAF-mediated paracrine resistance that can be overcome by MET TKIs. However, 'Cell Type specific labeling using Amino acid Precursors' (CTAP)-based expression and phosphoproteomics in direct coculture also highlighted a critical role for the fibronectin-integrin pathway. Flow cytometry analysis confirmed activation of integrin β1 (ITGB1) in lung cancer cells by CAF coculture. Treatment with pharmacological inhibitors, cancer cell-specific silencing or CRISPR-Cas9-mediated knockout of ITGB1 overcame adhesion protein-mediated resistance. Concurrent targeting of MET and integrin signaling effectively abrogated CAF-mediated resistance of EML4-ALK -driven NSCLC cells to ALK TKIs in vitro . Consistently, combination of the ALK TKI alectinib with the MET TKI capmatinib and/or the integrin inhibitor cilengitide was significantly more efficacious than single agent treatment in suppressing tumor growth using an in vivo EML4-ALK -dependent allograft mouse model of NSCLC. In summary, these findings emphasize the complexity of resistance-associated crosstalk between CAFs and cancer cells, which can involve multiple concurrent signaling pathways, and illustrate how comprehensive elucidation of paracrine and juxtacrine resistance mechanisms can inform on more effective therapeutic approaches.

CAFs and T cells interplay: The emergence of a new arena in cancer combat

The interaction between the immune system and the tumor matrix has a huge impact on the progression and treatment of cancer. This paper summarizes and discusses the crosstalk between T cells and cancer-associated fibroblasts (CAFs). CAFs can also produce inhibitors that counteract the function of T cells and promote tumor immune escape, while T cells can also engage in complex two-way interactions with CAFs through direct cell contact, the exchange of soluble factors such as cytokines, and the remodeling of the extracellular matrix. Precise targeted intervention can effectively reverse tumor-promoting crosstalk between T cells and CAFs, improve anti-tumor immune response, and provide a new perspective for cancer treatment. Therefore, it is important to deeply understand the mechanism of crosstalk between T cells and CAFs. This review aims to outline the underlying mechanisms of these interactions and discuss potential therapeutic strategies that may become fundamental tools in the treatment of cancer, especially hard-to-cure cancers.

Cancer-associated fibroblast-derived colony-stimulating factor 2 confers acquired osimertinib resistance in lung adenocarcinoma via promoting ribosome biosynthesis

Acquired resistance is a major obstacle to the therapeutic efficacy of osimertinib in lung adenocarcinoma (LUAD), but the underlying mechanisms are still not fully understood. Cancer-associated fibroblasts (CAFs) are the most abundant stromal cell type in LUAD tumor-microenvironment (TME) and have emerged as a key player in chemoresistance. However, the function of CAFs in osimertinib resistance is still unclear. Here, we showed that CAFs derived from osimertinib-resistant LUAD tissues (CAFOR) produced much more colony-stimulating factor 2 (CSF2) than those isolated from osimertinib-sensitive tissues. CAFOR-derived CSF2 activated the Janus kinase 2 (JAK2)/Signal transducer and activator of transcription 3 (STAT3) signaling pathway and upregulated lnc-CSRNP3 in LUAD cells. Lnc-CSRNP3 then promoted the expression of nearby gene CSRNP3 by recruiting chromodomain helicase DNA binding protein 9 (CHD9) and inhibited the phosphatase activity of the serine/threonine protein phosphatase 1 catalytic subunit α (PP1α), thereby induced osimertinib resistance by enhancing ribosome biogenesis. Collectively, our study reveals a critical role for CAFs in the development of osimertinib resistance and identifies the CSF2 pathway as an attractive target for monitoring osimertinib efficacy and overcoming osimertinib resistance in LUAD.

Novel molecular subtypes of METex14 non-small cell lung cancer with distinct biological and clinical significance

Not all MET exon 14 skipping (METex14) NSCLC patients benefited from MET inhibitors. We hypothesized an inter-tumoral heterogeneity in METex14 NSCLC. Investigations at genomic and transcriptomic level were conducted in METex14 NSCLC samples from stage I-III and recurrent/metastatic patients as discovery and validation cohort. Four molecular subtypes were discovered. MET-Driven subtype, with the worst prognosis, displayed MET overexpression, enrichment of MET-related pathways, and higher infiltration of fibroblast and regulatory T cells. Immune-Activated subtype having the most idea long-term survival, had higher tertiary lymphoid structures, spatial co-option of PD-L1+ cancer cells, and GZMK+ CD8+ T cell. FGFR- and Bypass-Activated subtypes displayed FGFR2 overexpression and enrichments of multiple oncogenic pathways respectively. In the validation cohort, patients with MET-Driven subtype had better response to MET inhibitors than those with MET overexpression. Thus, molecular subtypes of METex14 NSCLC with distinct biological and clinical significance may indicate more precise therapeutic strategies for METex14 NSCLC patients.

Comprehensive integrated single-cell RNA sequencing analysis of brain metastasis and glioma microenvironment: Contrasting heterogeneity landscapes

Understanding the specific type of brain malignancy, source of brain metastasis, and underlying transformation mechanisms can help provide better treatment and less harm to patients. The tumor microenvironment plays a fundamental role in cancer progression and affects both primary and metastatic cancers. The use of single-cell RNA sequencing to gain insights into the heterogeneity profiles in the microenvironment of brain malignancies is useful for guiding treatment decisions. To comprehensively investigate the heterogeneity in gliomas and brain metastasis originating from different sources (lung and breast), we integrated data from three groups of single-cell RNA-sequencing datasets obtained from GEO. We gathered and processed single-cell RNA sequencing data from 90,168 cells obtained from 17 patients. We then employed the R package Seurat for dataset integration. Next, we clustered the data within the UMAP space and acquired differentially expressed genes for cell categorization. Our results underscore the significance of macrophages as abundant and pivotal constituents of gliomas. In contrast, lung-to-brain metastases exhibit elevated numbers of AT2, cytotoxic CD4+ T, and exhausted CD8+ T cells. Conversely, breast-to-brain metastases are characterized by an abundance of epithelial and myCAF cells. Our study not only illuminates the variation in the TME between brain metastasis with different origins but also opens the door to utilizing established markers for these cell types to differentiate primary brain metastatic cancers.

Refining the optimal CAF cluster marker for predicting TME-dependent survival expectancy and treatment benefits in NSCLC patients

The tumor microenvironment (TME) plays a pivotal role in the onset, progression, and treatment response of cancer. Among the various components of the TME, cancer-associated fibroblasts (CAFs) are key regulators of both immune and non-immune cellular functions. Leveraging single-cell RNA sequencing (scRNA) data, we have uncovered previously hidden and promising roles within this specific CAF subgroup, paving the way for its clinical application. However, several critical questions persist, primarily stemming from the heterogeneous nature of CAFs and the use of different fibroblast markers in various sample analyses, causing confusion and hindrance in their clinical implementation. In this groundbreaking study, we have systematically screened multiple databases to identify the most robust marker for distinguishing CAFs in lung cancer, with a particular focus on their potential use in early diagnosis, staging, and treatment response evaluation. Our investigation revealed that COL1A1, COL1A2, FAP, and PDGFRA are effective markers for characterizing CAF subgroups in most lung adenocarcinoma datasets. Through comprehensive analysis of treatment responses, we determined that COL1A1 stands out as the most effective indicator among all CAF markers. COL1A1 not only deciphers the TME signatures related to CAFs but also demonstrates a highly sensitive and specific correlation with treatment responses and multiple survival outcomes. For the first time, we have unveiled the distinct roles played by clusters of CAF markers in differentiating various TME groups. Our findings confirm the sensitive and unique contributions of CAFs to the responses of multiple lung cancer therapies. These insights significantly enhance our understanding of TME functions and drive the translational application of extensive scRNA sequence results. COL1A1 emerges as the most sensitive and specific marker for defining CAF subgroups in scRNA analysis. The CAF ratios represented by COL1A1 can potentially serve as a reliable predictor of treatment responses in clinical practice, thus providing valuable insights into the influential roles of TME components. This research marks a crucial step forward in revolutionizing our approach to cancer diagnosis and treatment.

Neoadjuvant sintilimab plus chemotherapy in EGFR-mutant NSCLC: Phase 2 trial interim results (NEOTIDE/CTONG2104)

The clinical efficacy of neoadjuvant immunotherapy plus chemotherapy remains elusive in localized epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC). Here, we report interim results of a Simon's two-stage design, phase 2 trial using neoadjuvant sintilimab with carboplatin and nab-paclitaxel in resectable EGFR-mutant NSCLC. All 18 patients undergo radical surgery, with one patient experiencing surgery delay. Fourteen patients exhibit confirmed radiological response, with 44% achieving major pathological response (MPR) and no pathological complete response (pCR). Similar genomic alterations are observed before and after treatment without influencing the efficacy of subsequent EGFR-tyrosine kinase inhibitors (TKIs) in vitro. Infiltration and T cell receptor (TCR) clonal expansion of CCR8+ regulatory T (Treg)hi/CXCL13+ exhausted T (Tex)lo cells define a subtype of EGFR-mutant NSCLC highly resistant to immunotherapy, with the phenotype potentially serving as a promising signature to predict immunotherapy efficacy. Informed circulating tumor DNA (ctDNA) detection in EGFR-mutant NSCLC could help identify patients nonresponsive to neoadjuvant immunochemotherapy. These findings provide supportive data for the utilization of neoadjuvant immunochemotherapy and insight into immune resistance in EGFR-mutant NSCLC.

Single-cell analyzing of tumor microenvironment and cell adhesion between early and late-stage lung cancer

Lung adenocarcinoma (LUAD) is a highly heterogeneous disease that threaten human life with serious incidence and high mortality. High heterogeneity of tumor microenvironment (TME) was reported in multiple studies. However, the factor of controlling the tumor migration progression between eary and late-stage LUAD is still not fully understood. In this study, we conducted a comprehensive analysis of single-cell RNA sequencing (scRNA-seq) data of LUAD obtained from the GEO database. The identification of cell clusters revealed significant expansion of epithelial cells in late-stage patients. Interpretation of the cell-cell communication results between early-stage and late-stage patient samples indicated that early tumor cells may interact with epithelial cells through the TGF-β pathway to promote tumor progression. The cell cycle analysis demonstrated a significant increase in the number of cells in the G2 and M phases in late-stage lung cancer. Further analysis using Non-negative Matrix Factorization (NMF) revealed early-stage cell-specific gene features involved in cell adhesion-related biological processes. Among these, the Tensin (TNS) gene family, particularly TNS1, showed high expression in epithelial cells and fibroblasts of early-stage samples, specifically associated with cell adhesion. Survival analysis using TCGA database for LUAD demonstrated that patients with high expression of TNS1 exhibited significantly higher overall survival rates compared to those with low expression. Immunofluorescence experiments have demonstrated co-expression of TNS1 with fibroblast and tumor cell markers (α-SMA and EPCAM). Immunohistochemistry experiments further validated the significantly higher expression levels of TNS1 in early-stage LUAD tissues compared to late-stage lung cancer tissues (P<0.05). Pathway experiments have shown that early-stage tumor patients with high expression of TNS1 exhibit stronger phosphorylation levels of Akt and mTOR, indicating a more potent activation of the Akt/mTOR signaling pathway. In conclusion, the results of this study demonstrate that TNS1 is an adhesive molecule in the immune microenvironment of early-stage tumor cells, and it may serve as a novel prognostic marker for lug cancer.

Non-small cell lung cancer cells and concomitant cancer therapy induce a resistance-promoting phenotype of tumor-associated mesenchymal stem cells

Introduction

The tumor microenvironment gained attraction over the last decades as stromal cells significantly impact on tumor development, progression and metastasis, and immune evasion as well as on cancer therapy resistance. We previously reported that lung-resident mesenchymal stem cells (MSCs) were mobilized and activated in non-small cell lung cancer (NSCLC) progression and could even mediate radiation resistance in co-cultured NSCLC cells.

Methods

We investigated how MSCs were affected by NSCLC cells in combination with cancer (radiation) therapy in indirect co-cultures using tumor-conditioned medium and Transwells or direct three-dimensional NSCLC-MSC spheroid co-cultures in order to unravel the resistance-mediating action of tumor-associated MSCs.

Results

Although no obvious phenotypic and functional alterations in MSCs following NSCLC co-culture could be observed, MSC senescence was induced following co-applied radiotherapy (RT). Global gene expression profiling, in combination with gene set enrichment analysis upon treatment, was used to confirm the senescent phenotype of irradiated MSC and to reveal relevant senescence-associated secretory phenotype (SASP) factors that could meditate NSCLC RT resistance. We identified senescent tumor-associated MSC-derived serine proteinase inhibitor (serpin) E1/PAI1 as potential SASP factor mediating NSCLC progression and RT resistance.

Discussion

Specified intra-tumor-stroma interactions and cell type-specific pro-tumorigenic functions could not only improve lung cancer classification but could even be used for a more precise profiling of individual patients, finally paving an additional way for the discovery of potential drug targets for NSCLC patients.

Dissecting the Spatially Restricted Effects of Microenvironment-Mediated Resistance on Targeted Therapy Responses

The response of tumors to anti-cancer therapies is defined not only by cell-intrinsic therapy sensitivities but also by local interactions with the tumor microenvironment. Fibroblasts that make tumor stroma have been shown to produce paracrine factors that can strongly reduce the sensitivity of tumor cells to many types of targeted therapies. Moreover, a high stroma/tumor ratio is generally associated with poor survival and reduced therapy responses. However, in contrast to advanced knowledge of the molecular mechanisms responsible for stroma-mediated resistance, its effect on the ability of tumors to escape therapeutic eradication remains poorly understood. To a large extent, this gap of knowledge reflects the challenge of accounting for the spatial aspects of microenvironmental resistance, especially over longer time frames. To address this problem, we integrated spatial inferences of proliferation-death dynamics from an experimental animal model of targeted therapy responses with spatial mathematical modeling. With this approach, we dissected the impact of tumor/stroma distribution, magnitude and distance of stromal effects. While all of the tested parameters affected the ability of tumor cells to resist elimination, spatial patterns of stroma distribution within tumor tissue had a particularly strong impact.

Cancer-associated fibroblasts: heterogeneity and their role in the tumor immune response

In recent decades, many reports have been published on the composition and function of the tumor microenvironment (TME), among which cancer-associated fibroblasts (CAFs) have received much attention. CAFs have different degrees of heterogeneity in terms of their origin, phenotype, and function and can be divided into different subpopulations. These subgroups may play different roles in the occurrence and development of tumors. In addition, CAFs are closely associated with tumor immunity and have been found to regulate immune cell activity and to suppress the tumor immune response. In this review, we systematize the heterogeneity and characteristics of CAFs, discuss how specific CAF subgroups contribute to cancer progression by inducing an immunosuppressive microenvironment, and finally, we examine the future clinical applications of CAF subgroups.

miR-200-mediated inactivation of cancer-associated fibroblasts via targeting of NRP2-VEGFR signaling attenuates lung cancer invasion and metastasis

Cancer-associated fibroblasts (CAFs) play a substantial role in promoting cancer cell motility, drug resistance, angiogenesis, and metastasis; therefore, extensive research has been conducted to determine their mode of activation. We aimed to identify whether miRNA-200 (miR-200), a widely recognized suppressor of epithelial-mesenchymal transition, prevents CAFs from promoting cancer progression. Overexpression of miR-200 prevented CAFs from promoting lung cancer cell migration, invasion, tumorigenicity, and metastasis. Additionally, miR-200 suppressed the ability of CAFs to recruit and polarize macrophages toward the M2 phenotype, as well as the migration and tube formation of vascular endothelial cells. NRP2, a co-receptor of vascular endothelial growth factor receptor (VEGFR), was confirmed to be a target of miR-200, which mediates the functional activity of miR-200 in CAFs. NRP2-VEGFR signaling facilitates the secretion of VEGF-D and pleiotrophin from CAFs, leading to the activation of cancer cell migration and invasion. These findings suggest that miR-200 remodels CAFs to impede cancer progression and metastasis and that miR-200 and NRP2 are potential therapeutic targets in the treatment of lung cancer.