Diversity and Biology of Cancer-Associated Fibroblasts

Tumor organoids in cancer medicine: from model systems to natural compound screening

CONTEXT

The advent of tissue engineering and biomedical techniques has significantly advanced the development of three-dimensional (3D) cell culture systems, particularly tumor organoids. These self-assembled 3D cell clusters closely replicate the histopathological, genetic, and phenotypic characteristics of primary tissues, making them invaluable tools in cancer research and drug screening.

OBJECTIVE

This review addresses the challenges in developing in vitro models that accurately reflect tumor heterogeneity and explores the application of tumor organoids in cancer research, with a specific focus on the screening of natural products for antitumor therapies.

METHODS

This review synthesizes information from major databases, including Chemical Abstracts, Medicinal and Aromatic Plants Abstracts, ScienceDirect, Google Scholar, Scopus, PubMed and Springer Link. Publications were selected without date restrictions, using terms such as 'organoid', 'natural product', 'pharmacological', 'extract', 'nanomaterial' and 'traditional uses'. Articles related to agriculture, ecology, synthetic work or published in languages other than English were excluded.

RESULTS AND CONCLUSIONS

The review identifies key challenges related to the efficiency and variability of organoid generation and discusses ongoing efforts to enhance their predictive capabilities in drug screening and personalized medicine. Recent studies utilizing patient-derived organoid models for natural compound screening are highlighted, demonstrating the potential of these models in developing new classes of anticancer agents. The integration of natural products with patient-derived organoid models presents a promising approach for discovering novel anticancer compounds and elucidating their mechanisms of action.

A microfluidic co-culture platform for lung cancer cells electrotaxis study under the existence of stromal cells

Tumor metastasis is an important reason for the poor prognosis and high mortality in cancer patients. As major component of stromal cells in tumor microenvironment, cancer-associated fibroblasts (CAFs) secreted various factors to promote tumor metastasis. Studies have indicated that endogenous direct current electric field (dcEF) around tumor tissue induced directional migration of cancer cells. However, the regulatory effect of CAFs on cancer migration under dcEF stimulation is still unknown. In this study, a two-layers polydimethylsiloxane (PDMS)-based microfluidic chip was fabricated. The introduction of concave structures achieved the non-contacted co-culture of different cell types, and parallel channels in the chip provided stable and homogeneous dcEF. Cells electrotactic response was evaluated under co-culture circumstance. The results showed that CAFs exhibited directional migration towards anode under dcEF stimulation, while A549 cells had a trend of directional migration towards cathode. The co-existence of CAFs and dcEF significantly enhanced the motility and cathodal migration of A549 cells, suggesting synergistic influences of chemotaxis from CAFs and electrotaxis from dcEF stimulation. Moreover, we demonstrated that lung normal fibroblasts acquired CAFs properties after stimulated by dcEF, characterizing by increasing gene expression of α-SMA and IL-6. Overall, Our device and study provide new insight for tumor electrotaxis in complex microenvironment.

Pan-cancer analysis identifies EIPR1 as a potential prognostic and immunological biomarker for lung adenocarcinoma and its functional validation

BACKGROUND

EARP and GARP complex-interacting protein 1 (EIPR1) may be a new oncogene in tumors, influencing the prognosis and invasion of cancer. However, a systematic analysis of the function of EIPR1 in various cancers remains vacant. Thus, we proceeded with a comprehensive analysis to ascertain the role of EIPR1 among various cancers.

METHODS

We explored EIPR1 expression in pan-cancer, and its association with clinical stage, survival, gene mutations and methylation by the TIMER 2.0, GEPIA2, cBioPortal, and UALCAN. The protein-protein interaction (PPI) network, immune infiltration, and immune checkpoint assessments of EIPR1 was performed using the STRING and SangerBox. The role of EIPR1 expression in lung adenocarcinoma (LUAD) was explored by the R software. The impact of EIPR1 expression on LUAD progression was studied through in vitro assays.

RESULTS

EIPR1 was overexpressed in most cancers and revealed as a potential prognostic biomarker in tumors, involving in tumorigenesis by affecting its methylation and gene mutations. The immune infiltration and immune checkpoints of tumors were related to the expression of EIPR1. Additionally, EIPR1 expression affected the survival, diagnosis, clinicopathological features, tumor microenvironment, and drug sensitivity of LUAD patients. Validation studies demonstrated that EIPR1 knockdown suppressed the malignant growth, invasion, and migration of LUAD cells.

CONCLUSIONS

This study delivers an extensive landscape for the oncogenesis and immunological characteristics of EIPR1, which reveals that EIPR1 may serve as a potential biological target for future prognosis and immune treatment in tumors, especially in LUAD.

The function of microRNA related to cancer-associated fibroblasts in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignant tumor characterized by a poor prognosis. A prominent feature of PDAC is the rich and dense stroma present in the tumor microenvironment (TME), which significantly hinders drug penetration. Cancer-associated fibroblasts (CAFs), activated fibroblasts originating from various cell sources, including pancreatic stellate cells (PSCs) and mesenchymal stem cells (MSCs), play a critical role in PDAC progression and TME formation. MicroRNAs (miRNAs) are small, single-stranded non-coding RNA molecules that are frequently involved in tumorigenesis and progression, exhibiting either oncolytic or oncogenic activity. Increasing evidence suggests that aberrant expression of miRNAs can mediate interactions between cancer cells and CAFs, thereby providing novel therapeutic targets for PDAC treatment. In this review, we will focus on the potential roles of miRNAs that target CAFs or CAFs-derived exosomes in PDAC progression, highlighting the feasibility of therapeutic strategies aimed at restoring aberrantly expressed miRNAs associated with CAFs, offering new pathways for the clinical management of PDAC.

Spatial distribution and activation changes of T cells in pancreatic tumors according to KRAS mutation subtype

To enhance immunotherapy efficacy in pancreatic cancer, it is crucial to characterize its immune landscape and identify key factors driving immune alterations. To achieve this, we quantitatively analyzed the immune microenvironment using multiplex immunohistochemistry, assessing the spatial relationships between immune and tumor cells to correlate with patient survival rates and oncological factors. Additionally, through Whole Exome Sequencing analysis based on public data, we explored genetic mutations that could drive these compositions. Finally, we validated T cell (Tc) migration mechanisms using patient-derived tumor organoids with induced KRAS mutation subtypes. Through this approach, we obtained the following meaningful results. First, immune cells in pancreatic cancer are denser in stromal regions than near tumor cells, with higher Tc distribution linked to increased patient survival rates. Second, the distance between tumor and Tc was within 100 μm, with higher Tc density found within 15-30 μm of the tumor cells. Third, while increasing CAF levels correspond to higher Tc density, higher ECM density tends to decrease Tc presence. Fourth, compared to KRAS G12D, KRAS G12V mutation increases various immune cells, notably Tc, which is closely linked to a dramatic rise in vascular cells. Finally, Tc migration was enhanced in tumor organoids with the G12V mutation, attributed to a reduction in the secretion of immunosuppressive cytokines. Our results indicate that KRAS mutation subtypes influence immune cell composition and function in the pancreatic cancer microenvironment, leading to varied immunotherapy responses. This underscores the need for personalized immune therapeutics and research models specific to KRAS mutations.

APOC1 expressed in macrophages promotes the pulmonary metastasis of colorectal cancer via CCL2/CCL5

Metastasis is the main cause of death in colorectal cancer (CRC), and the lungs are common sites of metastasis. However, there is little effective target to intervene colorectal cancer pulmonary metastasis (CCPM), especially on its unique immune microenvironment. In this study, sixteen genes were identified as core CCPM-related differentially expressed genes (DEGs) between CRC and CCPM. Three genes including Apolipoprotein C1 (APOC1) were associated with prognosis, stage and metastasis of CRC. In immunohistochemistry, APOC1 was mainly expressed in macrophages, and expressed more in CCPM than CRC. Patients with synchronous CCPM, higher stage, poorer OS and CCPM-free interval tended to have higher expression. In experiments in vitro, knockdown of APOC1 in macrophages reduced the migration, invasion, and epithelial-mesenchymal transition of CRC cells. Knockdown of APOC1 in macrophages significantly decreased secretion of chemokines like CCL2 and CCL5. The pro-metastatic effect of macrophages expressing APOC1 was partially blocked by the antibodies of CCL2 and CCL5. Activation of STAT3 was a key process in APOC1's regulation of CCL2 and CCL5. In experiments in vivo, knockdown of APOC1 in macrophages reduced pulmonary metastasis. To conclude, APOC1 is one of core CCPM-related DEGs and associated with the metastasis and survival of CRC. Macrophages expressing APOC1 promote the CCPM by APOC1-STAT3-CCL2/CCL5 axis. APOC1 and macrophages expressing APOC1 play vital roles and may be potential therapeutic targets in CCPM.

Circ847 upregulation via CAFs suppresses salivary adenoid cystic carcinoma progression through VIM-EMT

Salivary adenoid cystic carcinoma (SACC) is prone to metastasis, which strongly affects its prognosis. Cancer-associated fibroblasts (CAFs) play important roles in SACC metastasis. The purpose of this study was to identify and explore the key regulatory mechanisms of the altered expression of circRNAs in SACC CAFs. In this study, we found that circRNA-847 (circ847) expression was inhibited by pretreatment with SACC CAFs. Cell function experiments confirmed that the downregulation of circ847 promoted the proliferation and metastasis of SACC cells and that overexpression of circ847 induced the opposite effects. Mechanistically, circ847 can bind to vimentin and regulate its stability, thereby regulating epithelial-mesenchymal transition (EMT)-related signaling. Histological staining of SACC patient specimens also confirmed that the expression of circ847 was negatively correlated with SACC lymph node and lung metastasis. As a proof of concept, we successfully inhibited SACC progression and metastasis in sciatic nerve invasion models and lung metastasis models of SACC by treating the mice with nanoparticle-encapsulated circ847 plasmids to induce circ847 overexpression. This study demonstrated that circ847 expression is inhibited by CAFs. Restoring the expression of circ847 can effectively inhibit the progression of SACC, providing new research ideas for the study of effective prevention and treatment strategies for SACC and the prediction of SACC distant metastasis risk and prognosis.

SMAD4 and KRAS Status Shapes Cancer Cell-Stromal Cross-Talk and Therapeutic Response in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) contains an extensive stroma that modulates response to therapy, contributing to the dismal prognosis associated with this cancer. Evidence suggests that PDAC stromal composition is shaped by mutations within malignant cells, but most previous work has focused on preclinical models driven by KrasG12D and mutant Trp53. Elucidation of the contribution of additional known oncogenic drivers, including KrasG12V mutation and Smad4 loss, is needed to increase the understanding of malignant cell-stromal cell cross-talk in PDAC. In this study, we used single-cell RNA sequencing to analyze the cellular landscape of Trp53-mutant mouse models driven by KrasG12D or KrasG12V, in which Smad4 was wild type or deleted. KrasG12DSmad4-deleted PDAC developed a fibro-inflammatory rich stroma with increased malignant JAK/STAT cell signaling and enhanced therapeutic response to JAK/STAT inhibition. SMAD4 loss in KrasG12V PDAC differently altered the tumor microenvironment compared with KrasG12D PDAC, and the malignant compartment lacked JAK/STAT signaling dependency. Thus, malignant cell genotype affects cancer cell and stromal cell phenotypes in PDAC, directly affecting therapeutic efficacy. Significance: SMAD4 loss differentially impacts malignant cell-stromal cell signaling and treatment sensitivity of pancreatic tumors driven by KRASG12D or KRASG12V, highlighting the importance of understanding genotype-phenotype relationships for precision therapy.

The transcriptional regulators GATA6 and TET1 regulate the TGF-β pathway in cancer-associated fibroblasts to promote breast cancer progression

Cancer-associated fibroblasts (CAFs) are pivotal drivers of tumor progression, yet the molecular mechanisms underlying their activation remain incompletely understood. Here, we identified the TET1/SMAD4/GATA6 regulatory axis as a central mechanism governing CAF transformation and function in breast cancer. Through integrative in vitro and in vivo models, we demonstrated that TET1, an epigenetic modulator, demethylates the SMAD4 promoter, enhancing SMAD4 expression. SMAD4 transcriptionally upregulates GATA6, which amplifies TGF-β signaling by directly activating the TGF-β promoter, establishing a self-reinforcing feedforward loop critical for CAF identity and stromal-tumor crosstalk. GATA6 and TET1 were significantly upregulated in breast CAFs compared to normal fibroblasts (NFs) and TGF-β-induced CAFs. Loss- or gain-of-function experiments revealed that these regulators control CAF survival, marker expression, and secretion of pro-tumorigenic factors. Knockdown of GATA6 or TET1 reduced CAF-mediated migration and invasion of breast cancer cells in vitro, while their overexpression enhanced cancer cell aggressiveness. Mechanistically, TET1-mediated epigenetic remodeling and GATA6-driven transcriptional activation converge on the TGF-β/SMAD pathway, sustaining CAF activation. In vivo, tumors derived from GATA6- or TET1-depleted CAFs exhibited reduced growth, proliferation, and CAF engraftment, underscoring their role in tumor progression. These findings position GATA6 and TET1 as promising targets to disrupt CAF-driven tumorigenesis, offering novel strategies for breast cancer treatment. By unraveling the epigenetic-transcriptional interplay within the tumor microenvironment, this study advances our understanding of stromal reprogramming and its implications for precision oncology.

Spatial mapping of gene signatures in H&E-stained images: a proof of concept for interpretable predictions using additive multiple instance learning

The relative abundance of cancer-associated fibroblast (CAF) subtypes influences a tumor's response to treatment, especially immunotherapy. However, the gene expression signatures associated with these CAF subtypes have yet to realize their potential as clinical biomarkers. Here, we describe an interpretable machine learning (ML) approach, additive multiple instance learning (aMIL), to predict bulk gene expression signatures from hematoxylin and eosin (H&E)-stained whole slide images (WSI), focusing on an immunosuppressive LRRC15+ CAF-enriched TGFβ-CAF signature. aMIL models accurately predicted TGFβ-CAF across various cancer types. Tissue regions contributing most highly to slide-level predictions of TGFβ-CAF were evaluated by ML models characterizing spatial distributions of diverse cell and tissue types, stromal subtypes, and nuclear morphology. In breast cancer, regions contributing most to TGFβ-CAF-high predictions ("excitatory") were localized to cancer stroma with high fibroblast density and mature collagen fibers. Regions contributing most to TGFβ-CAF-low predictions ("inhibitory") were localized to cancer epithelium and densely inflamed stroma. Fibroblast and lymphocyte nuclear morphology also differed between excitatory and inhibitory regions. Thus, aMIL enables a data-driven link between histologic features and transcription, offering biological interpretability beyond typical black-box models.

CXCL12 alone is enough to Reprogram Normal Fibroblasts into Cancer-Associated Fibroblasts

Cancer-associated fibroblasts (CAFs) are critical components of the tumor microenvironment (TME), playing significant roles in regulating cancer progression. However, the underlying mechanism of CAFs activation remains elusive. In this study, we aim to investigates the mechanisms by which CAFs promote the conversion of normal fibroblasts (NFs) to CAFs in lung cancer, with a focus on the role of p53 mutations and the CXCL12/STAT3 signaling axis. We found that CAFs significantly induced NFs to acquire CAFs properties (called CEFs), including upregulation of α-SMA and Vimentin, enhanced proliferation and migration, and increased ability to promote lung cancer cell migration. In vivo, CEFs accelerated A549 xenograft growth and induced spontaneous lung metastasis. CXCL12 was identified as a key factor in NFs-to-CEFs conversion, with its expression positively correlated with CAFs markers in lung cancer. Further investigation confirmed that CXCL12 is sufficient to reprogram NFs into CAFs through the STAT3 pathway. Notably, inhibiting CXCL12 signaling and the STAT3 pathway reduced the conversion of NFs to CAFs, thereby hindering lung cancer progression progression both in vitro and in vivo. Our study reveals CAFs could promote the conversion of NFs to CAFs-like cells through the CXCL12/STAT3 axis, enhancing tumor growth and metastasis in lung cancer. Therefore, inhibition of the CXCL12/STAT3 axis is a promising strategy for the treatment of lung cancers and other CXCL12-dependent malignancies.

Cancer-associated fibroblasts gene signature: a novel approach to survival prediction and immunotherapy guidance in colon cancer

Background

Fibroblasts can regulate tumour development by secreting various factors. For COAD survival prediction and CAFs-based treatment recommendations, it is critical to comprehend the heterogeneity of CAFs and find biomarkers.

Methods

We identified fibroblast-associated specific marker genes in colon adenocarcinoma by single-cell sequencing analysis. A fibroblasts-related gene signature was developed, and colon adenocarcinoma patients were classified into high-risk and low-risk cohorts based on the median risk score. Additionally, the impact of these risk categories on the tumor microenvironment was evaluated. The ability of CAFGs signature to assess prognosis and guide treatment was validated using external cohorts. Ultimately, we verified MAN1B1 expression and function through in vitro assays.

Results

Relying on the bulk RNA-seq and scRNA-seq data study, we created a predictive profile with 11 CAFGs. The profile effectively differentiated survival differences among cohorts of colon adenocarcinoma patients. The nomogram further effectively predicted the prognosis of COAD patients, with low-risk patients having a better prognosis. A higher immune infiltration rate and lower IC50 values of anticancer drugs were significant in the high-risk group. In cellular experiments, Following MAN1B1 knockdown, in cell assays, the colony formation, migration, and invasion ability of HCT116 and HT29 cell lines decreased.

Conclusion

Our CAFG signature provides important insights into the role of CAF cells in influencing COAD prognosis. It may also serve as a guide for selecting immunotherapy options and predicting chemotherapy responses in COAD patients.

Targeting B4GALT3 in BMSCs-EVs for Therapeutic Control of HCC via NF-κB pathway inhibition

Examining the communications in the tumor microenvironment (TME) specific to hepatocellular carcinoma (HCC), this exploration looks into the role played by beta-1,4-Galactosyltransferase III (B4GALT3) in bone marrow mesenchymal stromal cell-derived extracellular vesicles (BMSCs-EVs) regarding the NF-κB pathway and the triggering of cancer-associated fibroblasts (CAF). Through a multidisciplinary approach combining transcriptome sequencing, bioinformatic analysis, and various experimental models, the involvement of B4GALT3 in regulating CAF activity by modulating NF-κB signaling was brought to light in our study. The outcomes suggest that targeting B4GALT3 could impede HCC cell migration and invasion, promote apoptosis, and dampen tumor progression and metastasis, offering novel insights into potential therapeutic strategies for combating HCC.

Fibroblast atlas: Shared and specific cell types across tissues

Understanding the heterogeneity of fibroblasts depends on decoding the complexity of cell subtypes, their origin, distribution, and interactions with other cells. Here, we integrated 249,156 fibroblasts from 73 studies across 10 tissues to present a single-cell atlas of fibroblasts. We provided a high-resolution classification of 18 fibroblast subtypes. In particular, we revealed a previously undescribed cell population, TSPAN8+ chromatin remodeling fibroblasts, characterized by high expression of genes with functions related to histone modification and chromatin remodeling. Moreover, TSPAN8+ chromatin remodeling fibroblasts were detectable in spatial transcriptome data and multiplexed immunofluorescence assays. Compared with other fibroblast subtypes, TSPAN8+ chromatin remodeling fibroblasts exhibited higher scores in cell differentiation and resident fibroblast, mainly interacting with endothelial cells and T cells through ligand VEGFA and receptor F2R, and their presence was associated with poor prognosis. Our analyses comprehensively defined the shared and specific characteristics of fibroblast subtypes across tissues and provided a user-friendly data portal, Fibroblast Atlas.

Development and validation of basement membrane-related signatures for predicting postoperative recurrence, tumor microenvironment and drug candidates in chordomas

BACKGROUND

Skull base chordoma is a rare and aggressive bone tumor with a poor prognosis. The basement membrane (BM) plays an pivotal role in tumor progression. However, the involvement of BM-related genes in assessing the prognosis and influencing the biological behavior of skull base chordomas remains unclear.

METHODS

Patients with skull base chordoma undergoing endoscopic endonasal surgery were included in the study (77 patients for bulk transcriptome sequencing and 6 patients for single-cell RNA sequencing). A BM-related genes signature was established and validated using bulk transcriptome data. Additionally, we investigated the oncogenic potential of a key BM-related gene in chordoma cells in vitro.

RESULTS

A prognostic signature consisting of five BM-related genes was identified through LASSO Cox regression analysis. The accuracy and reliability of this signature were validated by the validation cohort. Multivariate Cox analysis and a nomogram demonstrated that the risk score serves as an independent and reliable prognostic factor for skull base chordoma. Moreover, the BM-related gene signature was significantly associated with the immune microenvironment, immune checkpoint expression, and drug sensitivity. Single-cell RNA sequencing analysis revealed both the chordoma tumor cell and the fibroblast contributed to the overall BM signature. Finally, in vitro experiments demonstrated that the knockdown of ITGB3, the hub gene in the signature, inhibited the proliferation and migration of chordoma cells via the PI3K-Akt pathway.

CONCLUSION

This study explored the critical role of BM-related genes in skull base chordoma, which affected postoperative recurrence and maligant behavior of chordoma via the PI3K-Akt signaling pathway.

Cancer-associated fibroblasts: multidimensional players in liver cancer

Cancer-associated fibroblasts (CAFs), the most abundant stromal cells in the tumor microenvironment (TME), control tumor growth through production and organization of the extracellular matrix (ECM) for a long time. However, the results from different studies that have focused on targeting CAFs to disturb tumor progression are extremely controversial. Recent studies using advanced single-cell RNA sequencing technology (scRNAseq) combined with multiple genetically engineered mouse models have identified diverse CAF subpopulations in the premalignant liver microenvironment (PME) of hepatocellular carcinoma (HCC) and TME of intrahepatic cholangiocarcinoma (ICC), providing a deeper understanding of the exact roles of each CAF subpopulation in cancer development. This review focuses on the specific protein markers, signaling pathways, and functions of various emerging CAF subclusters that contribute to the development of ICC and HCC. Elucidating the role and regulation of CAF subpopulations under different pathophysiological conditions will facilitate the discovery of new therapeutics that modulate CAF activity.

The NLRP1 Emerges as a Promising Therapeutic Target and Prognostic Biomarker Across Multiple Cancer Types: A Comprehensive Pan-Cancer Analysis

INTRODUCTION

Nod-like receptor family pyrin domain containing 1 (NLRP1) serves as the central component of the inflammasome complex and has emerged as a potential contributor to cancer development. Despite accumulating evidence, a comprehensive assessment of NLRP1 across various cancer types has yet to be undertaken.

METHODS

Several databases have evaluated NLRP1 expression across various cancer types in The Cancer Genome Atlas (TCGA). Additionally, studies have investigated the correlation between NLRP1 and various survival metrics, infiltration of cancer-associated fibroblasts, genetic alterations, drug sensitivity, and promoter methylation. Furthermore, research has explored the potential roles of NLRP1 and its interactions with other proteins.

RESULTS

Our analysis revealed decreased expression of NLRP1 in BLCA, BRCA, KICH, LUAD, LUSC, PRAD, and UCEC tumor tissues compared to normal tissues. We identified a significant correlation between NLRP1 expression and various cancer survival parameters, genetic mutations, and immune infiltration of cancer-associated fibroblasts. Furthermore, we observed that NLRP1 expression is regulated by promoter DNA methylation in ESCA. Abnormal expression of NLRP1 was associated with decreased sensitivity to multiple anti-tumor drugs and small compounds. NLRP1 was found to be involved in pathways associated with T cell receptors and chemokines.

CONCLUSIONS

Reduced NLRP1 expression contributes to cancer progression and holds potential as a crucial biomolecular marker for diagnostic, prognostic, and personalized therapeutic interventions across different malignancies.

The FBXW7-KMT2 axis in cancer-associated fibroblasts controls tumor growth via an epigenetic-paracrine mechanism

F-box and WD repeat domain-containing 7 (FBXW7) is a tumor suppressor that targets various oncoproteins for degradation, but its role in modulating cancer-associated fibroblasts (CAFs) in the tumor microenvironment remains elusive. Here, we report that FBXW7 expression is gradually downregulated in CAFs during the progression of human pancreatic and lung cancers. Mechanically, FBXW7 inhibits histone lysine methyltransferase 2 (KMT2) methyltransferase activity via retinoblastoma binding protein 5 (RbBP5) binding, whereas FBXW7 depletion abrogates the binding to activate KMT2, leading to increased H3K4 methylations and global upregulation of gene expression. Activation of the interleukin-17 (IL-17) signaling pathway triggers the secretion of cytokines and chemokines to promote migration, invasion, and sphere formation of lung cancer cells. Coinjection of Fbxw7-depleted mouse embryonic fibroblasts with cancer cells enhances in vivo tumor growth, demonstrating a paracrine effect. Hypoxia downregulates CAF FBXW7 via ETS proto-oncogene 1 (ETS1) to increase H3K4 methylation, whereas conditioned media from hypoxia-exposed CAFs promotes migration and invasion of pancreatic cancer cells, highlighting FBXW7's tumor-suppressing role through KMT2 inactivation.

Single-Cell Analysis Reveals Histone Deacetylation Factor Guide Intercellular Communication of Tumor Microenvironment that Contribute to Colorectal Cancer Progression and Immunotherapy

In this study, single-cell RNA-seq data were collected to analyze the characteristics of Histone deacetylation factor (HDF). The tumor microenvironment (TME) cell clusters related to prognosis and immune response were identified by using CRC tissue transcriptome and immunotherapy cohorts from public repository. We explored the expression characteristics of HDF in stromal cells, macrophages, T lymphocytes, and B lymphocytes of the CRC single-cell dataset TME and further identified 4 to 6 cell subclusters using the expression profiles of HDF-associated genes, respectively. The regulatory role of HDF-associated genes on the CRC tumor microenvironment was explored by using single-cell trajectory analysis, and the cellular subtypes identified by biologically characterized genes were compared with those identified by HDF-associated genes. The interaction of HDF-associated gene-mediated microenvironmental cell subtypes and tumor epithelial cells were explored by using intercellular communication analysis, revealing the molecular regulatory mechanism of tumor epithelial cell heterogeneity. Based on the expression of feature genes mediated by HDF-related genes in the microenvironment T-cell subtypes, enrichment scoring was performed on the feature gene expression in the CRC tumor tissue transcriptome dataset. It was found that the feature gene scoring of microenvironment T-cell subtypes (HDF-TME score) has a certain predictive ability for the prognosis and immunotherapy benefits of CRC tumor patients, providing data support for precise immunotherapy in CRC tumors.

Construction and significance of a breast cancer prognostic model based on cuproptosis-related genotyping and lncRNAs

BACKGROUND/PURPOSE

Cuproptosis may play a significant role in breast cancer (BC). We aimed to investigate the prognostic impact of cuproptosis-related lncRNAs in BC.

METHODS

Consensus clustering analysis categorized TCGA-BRCA samples into 3 clusters, followed by survival and immune analyses of the 3 clusters. LASSO-COX analysis was performed on cuproptosis-related lncRNAs differentially expressed in BC to construct a BC prognostic model. Gene Ontology/Kyoto Encyclopedia of Genes and Genomes (GO/KEGG) enrichment, immune, and drug prediction analyses were performed on the high-risk and low-risk groups. Cell experiments were conducted to analyze the results of drug prediction and two cuproptosis-related lncRNAs (AC104211.1 and LINC01863).

RESULTS

Significant differences were observed in survival outcomes and immune infiltration levels among the three clusters (p < 0.05). The validation of the model showed significant differences in survival outcomes between the high-risk and low-risk groups in both the training and validation sets (p < 0.05). Differential mRNAs between the two groups were significantly enriched in the Neuroactive ligand-receptor interaction and cAMP signaling pathway. Additionally, significant differences were found in immune infiltration levels, human leukocyte antigen (HLA) expression, Immunophenoscore (IPS) scores, and Tumor Immune Dysfunction and Exclusion (TIDE) scores between the two groups (p < 0.05). Drug prediction and corresponding cell experimental results showed that Trametinib, 5-fluorouracil, and AICAR significantly inhibited the viability of MCF-7 cells (p < 0.05). AC104211.1 and LINC01863 were found to impact the proliferation of BC cells.

CONCLUSION

The risk-scoring model obtained in this study may serve as a robust prognostic biomarker, potentially aiding in clinical decision-making for BC patients.

Unveiling the Role of the Cellular Tumor Microenvironment and the Therapeutic Targets it Provides in Cutaneous T-Cell Lymphoma

PURPOSE OF REVIEW

Cutaneous T-Cell Lymphoma (CTCL) poses challenges both in diagnosis and prognosis. The purpose of this review is to address the role of profiling immune and non-immune cells in the tumor microenvironment (TME) as it provides information for better diagnosis, prognosis, biomarker discovery, and personalized treatment strategies.

RECENT FINDINGS

Recent evidence suggests that the progression of CTCL is closely linked to the Tumor Microenvironment (TME) which comprises various cell types including immune cells, stromal cells, blood vessels, and the extracellular matrix. Cell profiling within the TME demonstrates the perplexity of intracellular communication of the different cell fates and their mediators as the disease progresses. CTCL as a rare form of non-Hodgkin lymphoma often misdiagnosed due to its similarity to other skin conditions. It encompasses diseases like Mycosis fungoides (MF) and Sézary Syndrome (SS), with the latter being more severe. Advances in studying the TME have shown its pivotal role in CTCL progression, highlighting the need for comprehensive cell profiling to enhance diagnosis, prognosis, and treatment personalization.

Pan-Cancer Analysis Shows that KIFC2 is a Potential Prognostic and Immunotherapeutic Biomarker for Multiple Cancer Types Including Bladder Cancer

KIFC2 plays an important role in prostate cancer progression and chemotherapy resistance, but the mechanism of its involvement in other malignancies remains unclear. Therefore, this study aimed to analyze and validate the mechanism of effect of KIFC2 in multiple tumors. Bioinformatic analysis was performed in conjunction with multiple databases (The Cancer Genome Atlas, Genotype-Tissue Expression Project, Human Protein Atlas, etc.) to fully explore the potential role of KIFC2 within individual tumors and to analyze the correlation with major research components such as prognosis, mutations, and the tumor microenvironment. The expression of KIFC2 demonstrates a significant correlation with the prognosis, clinical phenotype, tumor mutational burden, microsatellite instability, and tumor microenvironment across various malignancies and is associated with the modulation of diverse functional and signaling pathways. The differences in the expression of KIFC2 in the bladder cancer tissues (14 pairs) were statistically significant. The pan-cancer analysis in this study revealed the multifunctionality of KIFC2 in a variety of tumors, indicating a possible prognostic predictor and potential therapeutic target for tumors.

Tumor Microenvironment On-A-Chip and Single-Cell Analysis Reveal Synergistic Stromal-Immune Crosstalk on Breast Cancer Progression

Solid tumors develop within a complex environment called the tumor microenvironment (TME), which is sculpted by the presence of other cells, such as cancer-associated fibroblasts (CAFs) and immune cells like macrophages (Mφs). Despite the presence of immune cells, tumor cells orchestrate a tumor-supportive environment through intricate interaction with the components of the TME. However, the specific mechanism by which this intercellular dialogue is regulated is not fully understood. To that end, the development of an organotypic 3D breast TME-on-a-chip (TMEC) model, integrated with single-cell RNA sequencing analysis, is reported to mechanistically evaluate the progression of triple-negative breast cancer (TNBC) cells in the presence of patient-derived CAFs and Mφs. Extensive functional assays, including invasion and morphometric characterization, reveal the synergistic influence of CAFs and Mφs on tumor cells. Furthermore, gene expression and pathway enrichment analyses identify the involvement of the KYNU gene, suggesting a potential immune evasion mechanism through the kynurenine pathway. Lastly, the pharmacological targeting of the identified pathway is investigated.

Serum Mac2-binding protein glycosylated isomer (M2BPGi) as a prognostic biomarker in pancreatic ductal adenocarcinoma: iCAFs-derived M2BPGi drives tumor invasion

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a poor prognosis. Mac2-binding protein glycosylated isomer (M2BPGi), a known biomarker for liver fibrosis, is also elevated in other fibrotic tissues. However, its role in PDAC remains unexplored. This study investigates the potential of M2BPGi as a prognostic biomarker for PDAC and elucidates its role in cancer progression.

METHODS

We analyzed serum M2BPGi levels in 83 PDAC patients and 60 healthy controls, examining the relationship with clinical outcomes. Tissue immunostaining and in vitro experiments were conducted to investigate M2BPGi-secreting cells and its role.

RESULTS

Serum M2BPGi levels were significantly higher in PDAC patients than in controls (0.98 vs. 0.59, p < 0.0001). Notably, elevated serum M2BPGi was associated with worse progression-free survival (144 days vs. 260 days, p = 0.017) and overall survival (OS) (245 days vs. 541 days, p < 0.001) following chemotherapy. Multivariable Cox regression analysis further confirmed that a high serum M2BPGi level is an independent risk factor for OS (HR: 2.44, 95% CI 1.26-4.74, p = 0.008). Immunostaining revealed that M2BPGi is secreted by both cancer cells and cancer-associated fibroblasts (CAFs), with high M2BP expression in CAFs correlating with poor prognosis. Furthermore, M2BPGi-secreting CAFs exhibited characteristics of inflammatory CAFs. M2BPGi directly activated mTOR signaling and epithelial-mesenchymal transition in PDAC cells, enhancing their invasive and migratory capabilities.

CONCLUSIONS

Our findings identify M2BPGi as a promising prognostic biomarker for PDAC. Moreover, we demonstrate that inflammatory CAFs promote tumor invasion and contribute to poor outcomes by secreting M2BPGi, revealing a novel mechanism of PDAC progression.

Transitional CXCL14+ cancer-associated fibroblasts enhance tumour metastasis and confer resistance to EGFR-TKIs, revealing therapeutic vulnerability to filgotinib in lung adenocarcinoma

BACKGROUND

The heterogeneity of cancer-associated fibroblasts (CAFs) has become a crucial focus in understanding cancer biology and treatment response, revealing distinct subpopulations with specific roles in tumor pathobiology. CAFs have also been shown to promote resistance in lung cancer cells to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs). However, the specific CAF subsets responsible for driving tumor advancement and resistance to EGFR-TKIs in lung adenocarcinoma (LUAD) remain poorly understood.

METHODS

We integrate multiple scRNA-seq datasets to identify cell subclusters most relevant to tumor stage, patient survival, and EGFR-TKIs response. Additionally, in vitro and in vivo experiments, clinical tissue sample immunohistochemistry and patient plasma ELISA experiments are performed to validate key findings in independent LUAD cohorts.

RESULTS

By analyzing multiple scRNA-seq and spatial transcriptomic datasets, we identified a unique subset of CXCL14+ myofibroblastic CAFs (myCAFs), emerging during the early differentiation phase of pan-cancer invasiveness-associated THBS2⁺ POSTN⁺ COL11A1⁺ myCAFs. Notably, plasma levels of CXCL14 in LUAD patients correlate significantly with tumor stage. Mechanistically, this subset enhances tumor aggressiveness through epithelial-to-mesenchymal transition and angiogenesis. Among standard treatment regimens, transitional CXCL14+ myCAFs specifically confer resistance to EGFR-TKIs, while showing no significant impact on chemotherapy or immunotherapy outcomes. Through a pharmacological screen of FDA-approved drugs, we identified Filgotinib as an effective agent to counteract the EGFR-TKIs resistance conferred by this CAF subset.

CONCLUSIONS

In summary, our study highlights the role of the differentiated stage from transitional CXCL14+ myCAFs to invasiveness-associated myCAFs in driving tumor progression and therapy resistance in LUAD, positioning Filgotinib as a promising targeted therapy for this process. These insights may enhance patient stratification and inform precision treatment strategies in LUAD.

KEY POINTS

Single-cell analysis identifies transitional CXCL14+ myofibroblastic cancer-associated fibroblasts (myCAFs) predominantly exist in the advanced-stage lung adenocarcinoma (LUAD). Transitional CXCL14+ myCAFs fuel metastasis by promoting epithelial-mesenchymal transition (EMT) and angiogenesis on the spatial level. CXCL14 is a potential diagnostic marker for LUAD patients and predict the occurrence of metastasis. Transitional CXCL14+ myCAFs induce the resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and JAK1 inhibitor, filgotinib could reverse the effect.

PPY-Induced iCAFs Cultivate an Immunosuppressive Microenvironment in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is characterized by cancer cells surrounded by affluent stromal components, which may underlie their limited response to various therapeutic interventions, including immunotherapy. Inflammatory cancer-associated fibroblasts (iCAFs), a crucial subset of CAFs within the PDAC microenvironment, play a pivotal role in shaping an immunosuppressive microenvironment. In this study, single-cell RNA sequencing analysis is performed to screen for cancer cells-secreted proteins associated with iCAF induction, and PPY (pancreatic polypeptide) is validated as a potent inducer. Unlike previously reported iCAF inducers, PPY is a gastrointestinal hormone predominantly expressed in the pancreas, suggesting that targeting it may have minimal systemic effects. Multiplex immunohistochemistry (mIHC) on human PDAC tissue microarrays, orthotopic allograft mouse models, and co-culture experiments are utilized to validate the crucial role of PPY in iCAF induction. Mechanistic studies integrating mRNA sequencing, immunoprecipitation-mass spectrometry, and molecular docking reveal that PPY induces iCAFs by activating the non-canonical NF-κB pathway through EGFR. Importantly, targeting PPY enhanced the efficacy of anti-PD-1 immunotherapy in KPC (KrasLSL-G12D/+; Trp53LSL-R172H/+; Pdx1-Cre) mice, as evidenced by reduced tumor burden on PET-CT imaging and improved survival. This research is expected to provide a novel strategy for improving immunotherapy in PDAC by targeting a key inducer of iCAFs.

The role of chloride intracellular channel 4 in tumors

Tumors are among the most predominant health problems in the world, and the annual incidence of cancer is increasing globally; therefore, there is an urgent need to identify effective therapeutic targets. Chloride intracellular channel 4 (CLIC4) belongs to the family of chloride intracellular channels (CLICs), which are widely expressed in various tissues and organs, such as the brain, lung, pancreas, colorectum, and ovary, and play important roles in promoting apoptosis, promoting angiogenesis, maintaining normal proliferation of endothelial cells, and regulating the assembly and reconstruction of the cytoskeleton. The expression and function of CLIC4 in tumors varies. It has been reported that CLIC4 is low expressed in gastric cancer, skin cancer and prostate cancer, suggesting a tumor suppressor role. Interestingly, CLIC4 is overexpressed in pancreatic, ovarian and breast cancers, indicating a cancer-promoting role. CLIC4 expression is dysregulated in some solid tumors, which may be because CLIC4 is involved in the growth, migration or invasion of some cancer cells through various mechanisms. Regulation of CLIC4 expression may be a potential therapeutic strategy for some tumors. CLIC4 may be a promising therapeutic target and a biomarker for some cancers. In this study, we review the role of CLIC4 in several cancers and its value in the diagnosis and treatment of tumors.

Diversity and heterogeneity in human pancreaticobiliary maljunction revealed by single-cell RNA sequencing

PURPOSE

The etiology and pathogenesis of pancreaticobiliary maljunction (PBM) remain unclear, thus a comprehensive investigation of cellular diversity and microenvironmental differences is pivotal to elucidate the mechanisms driving PBM.

METHODS

We performed single-cell RNA sequencing on bile duct tissues from six patients, including three with PBM and three without (non-PBM). Pathway enrichment, transcription factor analysis, and cell-cell communication were analyzed to explore cellular interactions and functional states.

RESULTS

A total of 90,996 single cells and 11 distinct cell lineages were identified, revealing significant differences in cellular composition between the two groups. PBM group was characterized by a higher proportion of endothelial cells and fibroblasts, while B and T cells were less abundant. Three subtypes of fibroblasts, antigen-presenting, inflammatory, and myofibroblastic cancer-associated fibroblasts, with the myofibroblast subtype being predominant in PBM. We found heightened activity of the WNT and TWEAK signaling pathways in PBM, as well as increased ligand-receptor interactions between fibroblasts and other cell types, including epithelial and endothelial cells.

CONCLUSION

Fibroblasts play a central role in driving fibrosis and tissue remodeling in PBM through specific signaling pathways. These insights provide a foundation for future therapeutic strategies aimed at modulating fibroblast activity to prevent or mitigate fibrosis in PBM.

FOS-driven inflammatory CAFs promote colorectal cancer liver metastasis via the SFRP1-FGFR2-HIF1 axis

Rationale: Cancer-associated fibroblasts (CAFs) exhibit diverse functions, yet their roles in colorectal cancer liver metastasis (CRLM) remain poorly understood. Methods: Through integrated analysis of single-cell RNA sequencing and spatial transcriptomics from colorectal cancer patients (CRCP: non-metastatic primary tumors; CRCM: metastatic primary tumors with liver metastases), combined with in vitro and in vivo models to investigate the role of CAFs in CRLM. In vitro experiments included six groups to reveal the role of SFRP1-producing CAFs, comprising PBS (control) and recombinant human SFRP1 (rhSFRP1) treated SW480 cells, PBS (control) and recombinant mouse SFRP1 (rmSFRP1) treated CT26 cells, and conditioned medium (CM) derived from CAF-NC and CAF-Sfrp1 treated CT26 cells. Preclinical models were further employed to elucidate the role of SFRP1 in CRLM. Subcutaneous xenografts models were constructed from PBS (control) and rhSFRP1 treated SW480 cells. For orthotopic tumor metastasis models, CT26 cells were pre-cultured with CAF-NC or CAF-Sfrp1 and then orthotopically injected into BALB/c mice. Results: We identified an inflammatory CAF subtype (CFD+ iCAFs) associated with poor clinical outcomes, advanced staging, and metastasis. Transcriptional regulation analysis revealed FOS-mediated differentiation of CFD+ iCAFs drives SFRP1 overexpression. In vitro and in vivo experiments confirmed that SFRP1-producing CAFs promote tumor stemness and epithelial-mesenchymal transition (EMT). Mechanistically, SFRP1 from CFD+ iCAFs binds FGFR2, activating the HIF1 signaling pathway to enhance tumor stemness, EMT, and CRLM progression. Conclusion: This study highlights CFD+ iCAFs as key regulators of tumor-stromal interactions and identifies SFRP1 as a potential therapeutic target in CRLM.

Protocol to purify and culture human pancreatic cancer cells from patient-derived xenografts

Pancreatic ductal adenocarcinoma (PDAC) exhibits extensive inter- and intratumoral heterogeneity, along with a significant stromal component. This protocol outlines steps to generate patient-derived xenografts (PDXs), isolate and enrich human PDAC epithelial cells, and verify their identity using droplet digital PCR (ddPCR) and human-specific markers. It provides a robust approach for culturing cancer epithelial cells to develop a human PDAC model system. For complete details on the use and execution of this protocol, please refer to Grygoryev et al.1.

TGF-β-mediated activation of fibroblasts in cervical cancer: implications for tumor microenvironment and prognosis

Background

Cervical cancer (CC) is a prevalent female malignancy strongly influenced by the tumor microenvironment (TME). This study focuses on the role of TGF-β signaling in cancer-associated fibroblasts (CAFs) and its interaction with immune cells, aiming to elucidate its impact on CC progression.

Methods

The TME of CC patients was analyzed using scRNA-seq data and we identified the major cell types in the TME with a focus on the activation of the TGF-β signaling pathway in fibroblasts. Gene modules related to the TGF-β signaling pathway were identified by Weighted correlation network analysis (WGCNA). Using The Cancer Genome Atlas Cervical Squamous Cell Carcinoma and Endocervical Adenocarcinoma (TCGA-CESC) dataset, a prognostic gene model was constructed by univariate Cox, LASSO Cox and multivariate Cox regression analyses. For cellular validation, the mRNA level of prognostic model-related genes was tested via quantitative real-time real-time polymerase chain reaction (PCR). Thereafter, the following assays, including cell counting kit-8, scratch and wound healing assays, were applied to assess the viability, migration and invasion of CC cells.

Results

Analysis at single-cell resolution identified nine major cell types in the TME, and significant activation of the TGF-β signaling pathway in fibroblasts was correlated with tumor proliferation and differentiation. Strong TGF-β signaling communication between fibroblasts and macrophages and NK/T cells suggested a crucial role in the shaping of the immunosuppressive microenvironment. WGCNA analysis identified gene modules significantly associated with the TGF-β signaling pathway. The prognostic model constructed based on three genes, ITGA5, SHF and SNRPN, demonstrated good predictive ability in multiple datasets, validating its potential for clinical application. Meanwhile, the cellular validation assays have revealed the higher expression of ITGA5 and SNRPN and lower expression of SHF in CC cells. Further, ITGA5 knockdown suppressed the viability, migration and invasion of CC cells.

Conclusion

This study confirmed the important role of the TGF-β signaling pathway in CC, especially in fibroblasts on tumor microenvironment and tumor progression. The current model could effectively evaluate the prognosis of CC, providing a theoretical foundation for developing CC therapies according to the TGF-β signaling pathway. The present results provide new perspectives for further research on the pathological mechanisms and clinical management of CC.

Single-cell RNA sequencing and spatial transcriptomics reveal the heterogeneity and intercellular communication of cancer-associated fibroblasts in gastric cancer

BACKGROUND

Gastric cancer is a highly aggressive malignancy characterized by a complex tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs), which are a key component of the TME, exhibit significant heterogeneity and play crucial roles in tumor progression. Therefore, a comprehensive understanding of CAFs is essential for developing novel therapeutic strategies for gastric cancer.

METHODS

This study investigates the characteristics and functional information of CAF subtypes and explores the intercellular communication between CAFs and malignant epithelial cells (ECs) in gastric cancer by analyzing single-cell sequencing data from 24 gastric cancer samples. CellChat was employed to map intercellular communication, and Seurat was used to integrate single-cell sequencing data with spatial transcriptome data to reconstruct a comprehensive single-cell spatial map. The spatial relationship between apCAFs and cancer cells was analyzed using multicolor immunohistochemistry.

RESULTS

Cells were categorized into nine distinct categories, revealing a positive correlation between the proportions of epithelial cells (ECs) and fibroblasts. Furthermore, six fibroblast subpopulations were identified: inflammatory (iCAFs), pericytes, matrix (mCAFs), antigen-presenting (apCAFs), smooth muscle cells (SMCs), and proliferative CAFs (pCAFs). Each of these subpopulations was linked to various biological processes and immune responses. Malignant ECs exhibited heightened intercellular communication, particularly with CAF subpopulations, through specific ligand-receptor interactions. High-density regions of CAF subpopulations displayed spatial exclusivity, with pericytes serving as a source for iCAFs, mCAFs, and apCAFs. Notably, malignant ECs and apCAFs showed increased interactions, with certain ligand-receptor pairs potentially impacting the prognosis of gastric cancer. Multiplex immunohistochemistry (mIHC) confirmed the close spatial proximity of apCAFs to cancer cells in gastric cancer.

CONCLUSION

Our study provided a comprehensive characterization of CAF heterogeneity in gastric cancer and revealed the intricate intercellular networks within the TME. The identified CAF subpopulations and their interactions with malignant cells could serve as potential therapeutic targets.

Hypoxia-Induced Senescent Fibroblasts Secrete IGF1 to Promote Cancer Stemness in Esophageal Squamous Cell Carcinoma

Cancer-associated fibroblasts (CAF) contribute to cancer initiation and progression and play a pivotal role in therapeutic response and patient prognosis. CAFs exhibit functional and phenotypic heterogeneity, highlighting the need to clarify the specific subtypes of CAFs to facilitate the development of targeted therapies against protumorigenic CAFs. In this study, using single-cell RNA sequencing on patient samples of esophageal squamous cell carcinoma (ESCC), we identified a CAF subcluster associated with tumor stemness that was enriched in genes associated with hypoxia and senescence. The CAF subpopulation, termed as hypoxia-induced senescent fibroblasts (hsCAF), displayed high secretion of insulin-like growth factor 1 (IGF1). The hsCAFs inhibited AMP-activated protein kinase (AMPK) activity in cancer cells via IGF1 to promote tumor stemness. The formation of hsCAFs was induced by the synergetic effect of hypoxia and cancer cells. Activation of nuclear factor erythroid 2-related factor 2 (NRF2) in cancer cells under hypoxia drove IL1α production to trigger CAF senescence and IGF1 secretion via nuclear factor I A. Knockout of IGF1 in CAFs or nuclear factor erythroid 2-related factor 2 in ESCC cells suppressed the tumor growth and chemotherapy resistance induced by CAFs in vivo. Importantly, patients with high proportions of hsCAFs showed poor survival and a worse response to chemotherapy. In summary, these findings identify a hsCAF subpopulation generated by interplay between cancer cells and CAFs under hypoxic conditions that promotes ESCC stemness and reveal targeting hsCAFs as an effective therapeutic strategy against chemotherapy-resistant ESCC. Significance: A hypoxic microenvironment and cancer cells cooperate to induce a senescent fibroblast subset that supports tumor stemness, suggesting that targeting this cancer-associated fibroblast subpopulation is a potential therapeutic strategy to overcome chemoresistance.

UBC4: A Repurposed Drug Regimen for Adjunctive Use During Bladder Cancer Treatment

After it has metastasized, bladder cancer, the malignant transformation of the bladder urothelium, continues to be a common cause of death after maximal use of all currently available standard treatments. To address this problem in 2025, the drug repurposing movement within oncology aims to identify medicines in common general medical care use that have data indicating that they can interfere or inhibit a growth driving element that has been identified in bladder cancer. This paper now outlines extensive preclinical data showing that four drugs from general medical practice meet these criteria-the melatonergic drug ramelteon, the antidepressant fluoxetine, the antibiotic dapsone, and the analgesic drug celecoxib. This is the UBC4 regimen, meant as a possible adjunct added to standard treatments of metastatic bladder cancer. Three factors justify a clinical pilot trial of UBC4: (1) the UBC4 drugs are usually well tolerated and carry a low risk of harm, (2) the commonly fatal outcome of bladder cancer once it has widely metastasized, plus (3) the strong preclinical database showing UBC growth inhibition by each of the individual UBC4 drugs as outlined in this paper.

PAI-1-driven SFRP2high cancer-associated fibroblasts hijack the abscopal effect of radioimmunotherapy

The abscopal effect of radioimmunotherapy, wherein tumor shrinkage occurs beyond the irradiated field, is therapeutically promising but clinically rare. The mechanisms underlying this effect remain elusive. Here, in vivo genome-wide CRISPR screening identifies SFRP2 as a potential stromal regulator of the abscopal effect. SFRP2 exhibits cancer-associated fibroblast (CAF)-specific expression and radioimmunotherapy-mediated upregulation in unirradiated tumors. Conditional Sfrp2 knockout in CAFs boosts the abscopal effect by rewiring the vascular-immune microenvironment to promote CD8+ T cell recruitment to unirradiated tumors. In vivo lineage tracing reveals that elevated SFRP2 correlates with radioimmunotherapy-driven pericyte lineage commitment. Serum proteomics reveals that irradiated-tumor-secreted PAI-1 triggers distant tumor pericyte cell-fate transition into SFRP2high CAFs via the LRP1/p65 axis. Pharmacologically blocking SFRP2 or PAI-1 enhances the abscopal effect in humanized patient-derived xenograft models. Our findings collectively illustrate that PAI-1-induced SFRP2high CAFs serve as critical stromal regulator to hijack the abscopal effect, providing promising targets for enhancing radioimmunotherapy effectiveness.

Tumor cell-derived ISG15 promotes fibroblast recruitment in oral squamous cell carcinoma via CD11a-dependent glycolytic reprogramming

Cancer-associated fibroblast (CAF) recruitment and activation within the tumor microenvironment (TME) are increasingly acknowledged as drivers of oral squamous cell carcinoma (OSCC) tumor growth and metastasis. Therefore, the mechanisms underlying tumor cell and fibroblast crosstalk warrant further investigation. We discovered that ectopic interferon-stimulated gene 15 (ISG15) expression, which is a promising and novel oncoprotein biomarker elevated in a variety of cancers, enhanced OSCC growth and elevated collagen and α-smooth muscle actin (α-SMA) expression in ISG15-expressing tumors. Analysis of immunohistochemistry revealed high ISG15 expression in human oral tissues correlated with high expression of α-SMA and fibroblast activation protein (FAP). Fibroblast migration and recruitment by ISG15-expressing OSCC cells were confirmed by in vitro and in vivo experiments. Exogenous ISG15 induced fibroblast migration, morphological changes, and vimentin expression. Enrichment of glycolysis pathway genes, as well as increased glycolysis-related gene expression, glucose uptake, and lactate production were observed in ISG15-treated fibroblasts. Lactate release and fibroblast migration were blocked by a competitive inhibitor of glucose metabolism. Furthermore, the knockdown of integrin αL (ITGAL)/CD11a, a subunit of ISG15 receptor lymphocyte functional-associated antigen-1 (LFA-1), in immortalized fibroblasts diminished extracellular ISG15-mediated glycolysis and migration. Our findings suggest that ISG15 derived from OSCC cells interacts with fibroblasts through the LFA-1 receptor, leading to glycolytic reprogramming and promotion of fibroblast migration into the TME.

Identification of lactylation-associated fibroblast subclusters predicting prognosis and cancer immunotherapy response in colon cancer

BACKGROUND

Lactylation plays an important role in tumor progression. This study aimed to clarify the impact of lactylation on cancer-associated fibroblasts(CAFs).

METHODS

Single-cell and bulk RNA sequence data, along with survival information, were obtained from TCGA and GEO datasets. Significant lactylation-associated genes were acquired by differential analysis and used to construct a prognostic model via Cox and LASSO regression analyses. Next, single-cell analysis, enrichment and pathway analysis, pseudotemporal trajectory and survival analysis were used to identify significant lactylation-associated fibroblast subclusters in colon cancer. IMvigor210 and PRJEB23709 cohorts were applied to assess the response to immunotherapy. In vitro experiments were conducted to explore how lactylation affect fibroblasts.

RESULTS

We established a lactylation-associated prognostic model with 17 risk genes in TCGA and further validated it in GEO datasets. Single-cell analysis revealed the lactylation level of fibroblasts in colon cancer was greater than that in normal tissues. Moreover, five lactylation-associated fibroblast subclusters were identified via the NMF algorithm. Patients with lower scores of FB_2_CALD1, FB_3_TPM4 and FB_4_AHNAK subclusters had better clinical prognosis in colon cancer and were more likely to benefit from immunotherapy. Further experiments demonstrated that lactylation could enhance the proliferation, migration and invasion ability of fibroblasts and up-regulate the expression of COL1A1, which was similar to the effect of colon cancer cells.

CONCLUSION

This study identified key fibroblast subclusters with prognostic value and implied that lactylation might help transform fibroblasts into CAFs in colon cancer for the first time, which provides new paths for understanding the evolution of CAFs and cancer therapeutic strategies.

Pluripotent stem cell-derived mesenchymal stem cells for therapeutic applications, developmental study, and cancer research

Human mesenchymal stem cells (MSCs) have been widely studied and applied for the treatment of various diseases due to their crucial role in tissue repair and regeneration. Compared to MSCs isolated from somatic tissues, MSCs differentiated from human pluripotent stem cells (ps-MSCs) have demonstrated similar therapeutic effects while possessing some advantages in quality control and assurance, given their unlimited and consistent supply of source cells. This makes ps-MSCs highly druggable and promising for therapeutic applications. In this minireview, we introduce the latest progress in ps-MSC research, focusing on the therapeutic properties, origin, in vivo development, and application of ps-MSCs in cancer research. We will also discuss the perspectives and challenges of this relatively new source of MSCs.

Combined Therapy Targeting MET and Pro-HGF Activation Shows Significant Therapeutic Effect Against Liver Metastasis of CRPC

The liver is the most lethal metastatic site in castration-resistant prostate cancer (CRPC). Overexpression of MET protein has been reported in CRPC, and MET is an important driver gene in androgen-independent CRPC cells. Mouse CRPC cell line CRTC2 was established by subcutaneous injection of hormone-sensitive PC cells (TRAMP-C2) in castrated nude mice. CRCT2/luc2 cells were injected into the spleen of castrated nude mice, and liver metastasis was confirmed at 2 weeks post-injection. We administered MET inhibitor (MET-I) and HGF activator inhibitor (HGFA-I) to this liver metastasis model and assessed the therapeutic effect. After intrasplenic injection, CRTC2 showed a higher incidence of liver metastasis whereas no metastasis was observed in TRAMP-C2. Microarray analysis revealed increased expression of HGF, MET, and HPN, HGFAC (encoding HGF activating proteases) in liver metastasis. Proliferation of CRCT2 was significantly inhibited by co-administration of MET-I and HGFA-I by in vitro analysis with HGF-enriched condition. In an analysis of the mouse model, the combination-therapy group showed the strongest reduction for liver metastasis. Immunohistochemical staining also revealed the strongest decrease in phosphorylation of MET in the combination-therapy group. Co-culture with HGF-expressed mouse fibroblasts showed attenuation of the inhibitory effect of MET-I; however, additional HGFA-I overcame the resistance. We established an androgen-independent CRPC cell line, CRTC2, and liver metastasis model in mice. Significant effect was confirmed by combined treatment of MET-I and HGFA-I by in vitro and in vivo analysis. The results suggested the importance of combined treatment with both MET- and HGF-targeting agents in the treatment of HGF-enriched conditions including liver metastasis.

Regulation of cancer-associated fibroblasts for enhanced cancer immunotherapy using advanced functional nanomedicines: an updated review

The tumor microenvironment (TME) is a complex and dynamic ecosystem that plays a critical role in cancer progression. It comprises various cell types, including immune cells, tumor cells, and stromal cells. Among these, cancer-associated fibroblasts (CAFs) represent a heterogeneous population with diverse origins, phenotypes, and functions. Activated CAFs secrete multiple factors that promote tumor growth, migration, angiogenesis, and contribute to chemoresistance. Additionally, CAFs secrete extracellular matrix (ECM) components, such as collagen, which form a physical barrier that hinders the penetration of chemotherapeutic and immunotherapeutic agents. This ECM also influences immune cell infiltration, impeding their ability to effectively target tumor cells. As a result, modulating the activity of CAFs has emerged as a promising strategy to enhance the efficacy of tumor immunotherapy. Nano-delivery systems, constructed from various nanomaterials with high targeting specificity and biocompatibility, offer a compelling approach to deliver therapeutic agents or immunomodulatory factors directly to CAFs. This modulation can alter CAF function, reduce their tumor-promoting effects, and thereby improve the outcomes of immunotherapy. This review provides an in-depth exploration of the origins, functions, and interactions of CAFs within the TME, particularly in the context of immune suppression. Furthermore, it discusses the potential applications of functional nanocarrifers in modulating CAFs and enhancing the effectiveness of tumor immunotherapy, highlighting the significant progress and potential of nanotechnology in this area.

Broad-Spectrum Efficacy of CEACAM6-Targeted Antibody-Drug Conjugate with BET Protein Degrader in Colorectal, Lung, and Breast Cancer Mouse Models

Despite remarkable advances in cancer treatment, most solid cancers remain difficult to cure. We recently developed an antibody-drug conjugate (ADC; 84-EBET) for pancreatic cancer by using the carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) antibody #84.7 and the bromodomain and extra-terminal (BET) protein degrader EBET. In this study, we showed the overexpression of CEACAM6 in colorectal, lung, and breast cancers and the broad-spectrum efficacy of 84-EBET in mouse models of these cancers. In vitro assays using cancer organoids and cell lines of colorectal, lung, and breast cancers revealed that 84-EBET was more potent than ADCs with known approved payloads-DXd, SN38, and monomethyl auristatin E-or standard chemotherapies. In mouse studies, a single injection of 84-EBET induced marked regression of colorectal-, lung-, and breast cancer patient-derived xenograft tumors and cell line-derived xenograft tumors. Moreover, in mouse syngeneic colorectal cancer, lung cancer, and breast cancer models resistant to PD-1 antibody, the combination of 84-EBET and PD-1 antibody induced complete regression of most tumors. Mechanistically, 84-EBET degraded bromodomain-containing protein 4 in both cancer and stromal cells via bystander efficacy. It decreased stromal inflammatory phenotypes and increased activated T-cell numbers in tumors. These results demonstrate that delivering BET protein degraders to tumors and their microenvironments via a CEACAM6-targeted ADC may be effective against a wide range of solid cancers.

CAFs-derived TIAM1 Promotes OSCC Cell Growth and Metastasis by Regulating ZEB2

Previous studies have suggested that cancer-associated fibroblasts (CAFs) within the tumor microenvironment are a critical factor in tumorigenesis and tumor development. However, the regulatory mechanisms of CAFs on oral squamous cell carcinoma (OSCC) are poorly defined. A CAF-conditioned medium (CAF-CM) was collected and applied to culture OSCC cells. Then, cell viability, proliferation, migration, and invasion were evaluated using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), Transwell, and scratch healing assays. T-Lymphoma Invasion and Metastasis 1 (TIAM1), zinc finger E-box-binding homeobox 2 (ZEB2), E-cadherin, and increased N-cadherin protein levels were determined using western blot. TIAM1 and ZEB2 mRNA levels were measured using real-time quantitative polymerase chain reaction (RT-qPCR). Their interaction was analyzed using Co-immunoprecipitation (Co-IP) assay. SCC25 cells with or without (TIAM1-silencing) CAFs were subcutaneously inoculated in nude mice to assess the effect of TIAM1 in CAFs on OSCC tumor growth in vivo. CAFs expedited OSCC cell proliferation, migration, invasion, and EMT. TIAM1 and ZEB2 expression were upregulated in OSCC patients and OSCC cells, and the TIAM1 level was much higher in CAFs than in OSCC cells. Furthermore, TIAM1 knockdown in CAFs might partly abolish the promotion of CAFs on OSCC cell development, implying that TIAM1 might be secreted by CAFs into the culture medium to exert its effects inside OSCCs. TIAM1 might increase ZEB2 expression, and ZEB2 upregulation might partly reverse the repression of TIAM1 silencing in CAFs on OSCC cell malignant behaviors. In vivo studies confirmed that CAFs accelerated OSCC tumor growth, these effects were partially counteracted by TIAM1 downregulation. Overall, TIAM1 secreted by CAFs could expedite OSCC cell growth and metastasis by regulating ZEB2, providing a promising therapeutic target for OSCC treatment.

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.

Overexpression of fibroblast activation protein (FAP) in the stroma of proliferative inflammatory atrophy (PIA) and primary adenocarcinoma of the prostate

Fibroblast activation protein (FAP) is a serine protease upregulated at sites of tissue remodelling and cancer that represents a promising therapeutic and molecular imaging target. In prostate cancer, studies of FAP expression using tissue microarrays are conflicting, such that its clinical potential is unclear. Furthermore, little is known regarding FAP expression in benign prostatic tissues. Here we demonstrated, using a novel iterative multiplex immunohistochemistry assay in standard tissue sections, that FAP was nearly absent in normal regions ​but was increased consistently in regions of proliferative inflammatory atrophy (PIA). In carcinoma, FAP was expressed in all cases ​but was highly heterogeneous. High FAP levels were associated with increased pathological stage and cribriform morphology. We verified that FAP levels in cancer correlated with CD163+ M2 macrophage density. In this first report to quantify FAP protein in benign prostate and primary tumours, using standard large tissue sections, we clarify that FAP is present in all primary prostatic carcinomas, supporting its potential clinical relevance. The finding of high levels of FAP within PIA supports the injury/regeneration model for its pathogenesis and suggests that it harbours a protumourigenic stroma, yet ​high levels of FAP in benign regions could lead to false-positive FAP-based molecular imaging results in clinically localised prostate cancer.

Oncogenic Mutations and the Tumor Microenvironment: Drivers of Non-Small Cell Lung Cancer Progression

BACKGROUND/OBJECTIVES

Non-small cell lung cancer (NSCLC) is a major cause of cancer-related deaths globally. The study focuses on understanding the interplay between genetic mutations, cancer stem cells (CSCs), and the tumor microenvironment (TME) in driving NSCLC progression, resistance to therapies, and relapse.

METHODS

A systematic search was conducted in PubMed and Scopus databases to identify significant and valuable studies relevant to NSCLC, focusing on genetic mutations, CSCs, and the TME. Articles were selected based on their relevance, methodological severity, date of publication, and scientific soundness related to NSCLC biology and therapeutic strategies. This review synthesized findings from these sources to highlight key mechanisms and potential therapeutic interventions.

RESULTS

Mutations in critical genes in KRAS, EGFR, TP53, and other key genes interfere with stem cell regulation, promoting CSC-like behavior, resistance to therapy, and immune evasion. The tumor microenvironment (TME), including immune cells, fibroblasts, and extracellular matrix components, further supports tumor growth and reduction in treatment efficacy. Promising strategies, including CSC targeting, TME modulation, and the development of novel biomarkers, have shown potential in preclinical and clinical studies.

CONCLUSIONS

The association between genetic alterations, CSCs, the TME, and other cellular pathways-including cell metabolism and immune evasion-plays a crucial role in therapy resistance, highlighting the need for comprehensive treatment strategies. The combination of genomic profiling with TME-targeting therapies could lead to personalized treatment approaches, offering hope for better clinical outcomes and reduced mortality in NSCLC patients.

FAP upregulates PD-L1 expression in cancer-associated fibroblasts to exacerbate T cells dysfunction and suppress anti-tumor immunity

FAP-positive cancer-associated fibroblasts (CAFs), recognized as a critical subset of CAFs, have been implicated in fostering an immunosuppressive tumor microenvironment in various cancers. However, their potential mechanisms of immunosuppression, particularly in modulating T cells, remain elusive. In this study, multiple internal cohorts consisting of 328 patients as well as 5 external cohorts were integrated to delineate the association between unfavorable prognosis or therapeutic resistance and FAP+ CAFs in gastric cancer patients. Subsequently, using in vivo mice models and in vitro co-culture system, we found that elevated infiltration levels of FAP+ CAF exacerbated immunosuppression in the tumor microenvironment by facilitating CD8+ T cells dysfunction. Mechanistically, FAP impeded the degradation of STAT1 protein in CAFs, thereby sustaining PD-L1 transcription and fostering T cell exhaustion. Treatment with PD-L1 neutralizing antibodies effectively attenuated FAP-mediated immunosuppression, restoring anti-tumor immunity of T cells. Overall, our findings underscore the vital role of FAP+ CAFs in directly suppressing T cell-mediated anti-tumor immunity via PD-L1 upregulation, paving the way for the development of FAP-targeted therapies in clinical settings.

Advances in nanotechnology for targeting cancer-associated fibroblasts: A review of multi-strategy drug delivery and preclinical insights

Cancer-associated fibroblasts (CAFs) play a crucial role in the tumor microenvironment by promoting tumor growth, immune evasion, and metastasis. Recently, drug delivery systems targeting CAFs have emerged as a promising long-term and effective approach to cancer treatment. Advances in nanotechnology, in particular, have led to the development of nanomedicine delivery systems designed specifically to target CAFs, offering new possibilities for precise and personalized cancer therapies. This article reviews recent progress in drug delivery using nanocarriers that target CAFs. Additionally, we explore the potential of combining multiple therapies, such as chemotherapy and immunotherapy, with nanocarriers to enhance efficacy and overcome drug resistance. Although many preclinical studies show promise, the clinical application of nanomedicine still faces considerable challenges, especially in terms of drug penetration and large-scale production. Therefore, this review aims to provide a fresh perspective on CAF-targeted drug delivery systems and highlight potential future research directions and clinical applications.

CAFs-derived Exosomal miR-889-3p Might Repress M1 Macrophage Polarization to Boost ESCC Development by Regulating STAT1

Cancer-associated fibroblasts (CAFs) represent one of the major components of the tumor stroma, which might create an immunosuppressive tumor microenvironment by inducing and functionally polarizing protumoral macrophages. Previous studies indicated that exosomes derived from CAFs might transmit regulating signals and boost esophageal squamous cell carcinoma (ESCC) development. This study is designed to explore the role and mechanism of CAFs-derived exosomal microRNA-889-3p (miR-889-3p) in ESCC progression. Macrophage polarization was detected using flow cytometry. miR-889-3p, Tumor necrosis factor alpha (TNF-α), and inducible nitric oxide synthase (iNOS) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation, cycle progression, migration, and invasion were assessed using Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), scratch assay, and Transwell assays. α-SMA, FAP, CD63, CD81, and signal transducer and activator of transcription 1 (STAT1) protein levels were detected using western blot. Exosomes were characterized using an electron microscope and nanoparticle tracking analysis (NTA). Binding between miR-889-3p and STAT1 was predicted by Starbase, and verified by a dual-luciferase reporter and RNA pull-down. The effect of CAFs-derived exosomal miR-889-3p on ESCC tumor growth in vivo was detected using mice xenograft assay. miR-889-3p level was decreased in LPS-induced M0 macrophages. CAF-derived exosomal miR-889-3p knockdown suppressed ESCC proliferation, migration, and invasion. CAFs might transfer miR-889-3p to M0 macrophages via exosomes. STAT1 was a target of miR-889-3p. Besides, in vivo studies confirmed that CAFs-derived exosomal miR-889-3p can accelerate ESCC tumor growth by regulating STAT1. CAFs-derived exosomal miR-889-3p facilitates esophageal squamous cell carcinoma cell proliferation, migration, and invasion by inhibiting M1 macrophage polarization through down-regulation of STAT1, providing a promising therapeutic target for ESCC.

A PTT-Induced Feed-Back Carbon Nanosystem for Enhanced Breast Cancer Therapy by Extracellular Matrix Remodeling

In the treatment of breast cancer, the dense extracellular matrix (ECM) severely impedes drug delivery and immune cell infiltration, resulting in poor therapeutic effects. Photothermal therapy (PTT) has achieved promise in preclinical breast cancer studies. However, in tumor immunogenic cell death (ICD) induced by PTT, immune cells are almost confined around the tumor periphery due to the ECM, which weakens the immune response. Thus, this study developed a carbon nanosystem (LCTi) to explore the effectiveness of enhancing PTT through the ECM remodeling. After intravenous injection, LCTi accumulated in the tumor through iRGD-mediated active targeting, subsequently destroying tumor cells and inducing ICD under 808 nm laser irradiation. Simultaneously, losartan was photothermal-responsively released from LCTi to remodel the ECM, consequently enhancing PTT efficacy by alleviating hypoxia and improving the tumor immune microenvironment. Focusing on ECM remodeling, this study provides an attractive "PTT-reinforced PTT" feed-back strategy for future breast cancer therapy.

Potential Benefits of Adding Alendronate, Celecoxib, Itraconazole, Ramelteon, and Simvastatin to Endometrial Cancer Treatment: The EC5 Regimen

Metastatic endometrial cancer continues to be a common cause of death as of 2024, even after maximal use of all currently available standard treatments. To address this problem of metastatic cancer generally in 2025, the drug repurposing movement within oncology identifies medicines in common general medical use that have clinical or preclinical experimental data indicating that they interfere with or inhibit a specific growth driving element identified in a given cancer. The drug repurposing movement within oncology also uses data from large scale in vitro screens of thousands of drugs, looking for simple empirical growth inhibition in a given cancer type. This paper outlines the data showing that five drugs from general medical practice meet these evidence criteria for inhibition of endometrial cancer growth, the EC5 regimen. The EC5 regimen uses the osteoporosis treatment drug, alendronate; the analgesic drug, celecoxib; the antifungal drug, itraconazole; the sleep aid, ramelteon; and the cholesterol lowering drug, simvastatin. Side effects seen with these drugs are usually minimal and easily tolerated by patients.