Role Of Cancer-associated Fibroblasts Research Articles

Fibroblasts from HPV-negative oropharynx squamous cell carcinomas stimulate the release of osteopontin from cancer cells via the release of IL-6.

HPV-associated oropharyngeal squamous cell carcinoma (OPSCC) shows distinct biological and clinical behaviour when compared to HPV-negative OPSCC. The overall role of the tumour microenvironment (TME) in head and neck cancer progression and metastasis has been studied intensively, but differences in HPV-negative and HPV-positive OPSCCs are less understood. To investigate the role of cancer-associated fibroblasts (CAFs) and the functional interactions of normal tonsil fibroblasts (NTFs) and OP CAFs with HPV+ and HPV- OPSCC cells and explore novel candidates in tumour-fibroblast crosstalk. A retrospective cohort of 143 primary OPSCCs was characterised using HPV16/18 RNAScope assay, p16 IHC and ɑ-SMA. Four OPSCC, three NTF and 2 new OPSCC CAF cultures were used to assess the cytokine-based interactions using cytokine arrays on conditioned media (CM), followed by co-culture approaches to identify the role of individual cell types and the role of OPN (SPP1) and IL-6 in SCC/fibroblast communication. HPV status was associated with better overall survival. Although ɑ-SMA expression was observed in both OPSCC subtypes, it provided survival stratification only in the HPV-positive group (Log-Rank p = 0.02). Three normal tonsillar fibroblast cultures (NTFs) were characterised by induction of myofibroblastic and senescent phenotypes with similar reactivity to our published NOF phenotype. The OPSCC-derived CAF cultures were characterised and their baseline myofibroblastic and senescence phenotypes varied. Cytokine array analysis of CM to identify novel candidates in the crosstalk between OPSCC tumour cells and NTFs/CAFs identified differences in the cytokine profiles on comparison of HPV+ and HPV- OPSCC cells. Osteopontin (OPN/SPP1) was identified, particularly in HPV-negative OPSCC cell analyses. We have demonstrated that OPN was produced by the OPSCC cells and revealed an associated upregulation of IL-6 in fibroblasts. Treatment of NTFs with rOPN showed alteration in phenotype, including increased contraction and IL-6 production. Antibody-mediated inhibition of CD44v6 attenuated the production of IL-6 by OPN in NTFs. This investigation with OPSCC fibroblasts provides novel insights into the role of CAFs in OPSCC mediated by IL-6 stimulated release of OPN from HPV negative OPSCC cells. The details of HPV-positive SCC cell/fibroblast cytokine crosstalk remain elusive.

Cellular plasticity in the breast cancer ecosystem.

The complex interplay between genetically diverse tumor cells and their microenvironment significantly influences cancer progression and therapeutic responses. This review highlights recent findings on cellular plasticity and heterogeneity within the breast cancer ecosystem, focusing on the roles of cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs). We discuss evidence suggesting that breast cancer cells exhibit phenotypic plasticity driven by both intrinsic genetic factors and external microenvironmental cues, impacting treatment responses and disease recurrence. Moreover, single-cell RNA sequencing studies reveal diverse subtypes of CAFs and TAMs, each with distinct functional gene expression programs and spatial organization within the tumor microenvironment. Understanding the hierarchical relationships and niche cues governing cellular phenotypes offers new opportunities for targeted therapeutic interventions. By elucidating the organizational principles of the tumor ecosystem, future therapies may target phenotypic states or entire cellular niches, advancing precision medicine approaches in breast cancer treatment.

Abstract 2917: Purifying cancer-associated fibroblasts (CAFs) from glioblastoma and defining their role in therapeutic resistance

Abstract Glioblastoma (GBM), a challenging brain tumor, necessitates the development of new therapies due to poor patient prognoses, with a median survival of 14-16 months. Standard of care, as established almost 20 years ago, remains to be surgical resection followed by chemotherapy and radiation and till date there is no defined standard of care for recurrent GBM, highlighting the urgent need for the development of novel therapies. Recent studies have implicated the tumor microenvironment in these poor prognoses. While cancer associated fibroblasts (CAFs) are a key cellular component of the microenvironment of many systemic tumors, their presence in GBM had been doubted until we recently developed intriguing data identifying cells in GBM that express fibroblast markers, have fibroblast-like morphology, and, most importantly, transcriptomically resemble CAFs from systemic cancers rather than other stromal cells that express similar surface markers such as pericytes (Jain et al. 2023). Similar to other solid cancers, GBM CAFs increase tumor growth and drive immunosuppression. The role of CAFs in regulating these processes could have significant implications in response to standard of care therapy as well as novel immunotherapies. While our initial CAF isolation had just 50% purity, we have developed a novel flow-sorting algorithm for CAF enrichment driven by our bioinformatic data. Through this protocol, we have successfully established, the first of its kind, a biobank of patient derived GBM CAFs with greater than 90% purity. These CAFs are now being utilized to investigate their contribution in conferring resistance to chemotherapy (Temozolomide) and radiotherapy. The CAFs are also being assessed for their role in suppressing T cell function and resistance to immunotherapies. In parallel, the origin of GBM CAFs and their development trajectory is being analyzed to find molecular markers to specifically target CAFs in the GBM microenvironment. The work put together will provide insight on mechanisms employed by CAFs in altering the GBM microenvironment and a basis for developing novel combination approaches, alleviating therapeutic resistance caused due to the presence of CAFs in the GBM microenvironment. The results of this study have the potential to significantly attenuate therapeutic resistance in GBM and provide much needed treatment options and improvement in survival, for what remains one of the most dismal diagnoses in the clinic. Citation Format: Ankita Sati, Aakriti Mathur, Meeki Lad, Atul Saha, Manish K. Aghi. Purifying cancer-associated fibroblasts (CAFs) from glioblastoma and defining their role in therapeutic resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2917.

Abstract PR-011: Role of cancer associated fibroblasts in ovarian cancer relapse

Abstract Frequent relapse and development of chemoresistance leads to poor prognosis in ovarian cancer (OC). Cancer stem cells (CSCs) consist of a small subpopulation in the tumor that are typically resistant to cytotoxic chemotherapy and are a potential cause of relapse and chemoresistance. Using patient specimens as well as in vitro models, we determined that CSCs are enriched in a niche adjacent to cancer associated fibroblasts (CAFs) after chemotherapy. Cancer associated fibroblasts (CAFs) are a major constituent of the ovarian cancer tumor microenvironment and are highly enriched in the residual tumors following chemotherapy. Therefore, we studied the role of CAFs in promoting ovarian cancer chemoresistance and disease relapse by providing an optimal microenvironment for CSCs. CAFs isolated from ovarian cancer patient tumors were used in heterotypic 2D or 3D coculture systems with high-grade serous ovarian cancer cell lines or with patient-derived ovarian cancer cells to study their effect on CSCs and chemoresistance. Matched pre-and post-chemotherapy patient tumors were used to confirm our findings. CAFs significantly increased resistance to carboplatin and enriched CSCs by increasing their symmetric division as well as dedifferentiation of bulk ovarian cancer cells. Pre-coculture with CAFs increased in vivo tumor initiation capacity of the ovarian cancer cells by 10-fold. The CSC-CAF crosstalk responsible for CSC induction was found to be mediated by Wnt5a signaling. CRISPR knockdown of Wnt5a in CAFs or treatment with a specific Wnt5a inhibitor abrogated the induction of CSCs by CAFs. Only cancer cells with ROR2 Wnt coreceptor respond to Wnt5a signaling triggered by CAFs and developed into CSCs. Responders were found to signal through a non-canonical Wnt pathway involving the coreceptor ROR2, protein kinase C (PKC), and CAMP Responsive Element Binding Protein 1 (CREB1). Inhibition of each of them prevented CSC induction and functional rescue experiments confirmed the sequence of the Wnt5a-ROR2-PKC-CREB1 axis. Treatment of mouse xenografts was established by co-injection of CAFs and ovarian cancer cells, with the Wnt5a inhibitor sensitized them to carboplatin, and eliminated the CSCs in the residual tumors. Our results indicate that CAF-derived Wnt5a is instrumental in ovarian cancer CSC growth and maintenance. In the long term, our studies will broaden the understanding of the mechanism of CSC maintenance by the tumor microenvironment and contribute towards the development of novel therapeutic approaches to prevent ovarian cancer chemoresistance and relapse. Citation Format: Yiming Fang, Argha Ghosh, Ji Wang, Subramanyam Dasari, Dimitriy Zamarin, Anirban Kumar Mitra. Role of cancer associated fibroblasts in ovarian cancer relapse [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr PR-011.

Cancer-associated fibroblasts (CAFs) based model reveals potential for predicting bladder cancer patients’ prognoses and immunotherapy responses

Aim: The purpose of this study is to enhance the understanding of bladder cancer and the role of cancer-associated fibroblasts (CAFs) in its progression. We aim to identify CAF-specific biomarkers and develop a prognostic prediction model based on CAFs, thereby contributing to the advancement of treatment strategies and the identification of prognostic and predictive biomarkers for bladder cancer. Method: We employed single-cell RNA sequencing to detect biomarkers for CAFs in bladder cancer cells. Bladder cancer cohorts were categorized into low- and high-CAF groups using the ssGSEA algorithm. The study also explored the association between CAF-related scores, immune-related cells, and immune checkpoint-related genes. Furthermore, we performed GSVA analysis to understand the biological features of CAFs and their link to various cancer-related pathways. Result: Ten genes were identified as CAF markers in bladder cancer cells. A significant difference was found with 2712 differentially expressed genes between low-CAF and high-CAF tissues. The CAFs-based prognostic prediction model included nine genes (ALDH1L2, AL450384.2, EMP1, LINC02362, WFIKKN1, GOLGA8A, POU5F1, AL354919.2, PTPRR), which are potentially crucial in predicting bladder cancer prognosis. The GSVA analysis revealed the involvement of several cancer-related pathways, such as WNT, toll-like receptor, TGF-beta, MAPK, and MTOR signaling pathways, in the CAFs-based prognostic model. Conclusion: This study highlights the significant role of CAFs in the progression and prognosis of bladder cancer. The identified CAF biomarkers and the constructed prognostic model provide valuable insights for future research and potential therapeutic targets. CAF-dependent pathways are promising for the development of new treatments and improving the prognosis of bladder cancer patients.

AKT2S128/CCTαS315/319/323-positive cancer-associated fibroblasts (CAFs) mediate focal adhesion kinase (FAK) inhibitors resistance via secreting phosphatidylcholines (PCs)

Abnormal metabolism is regarded as an oncogenic hallmark related to tumor progression and therapeutic resistance. Present study employed multi-omics, including phosphoproteomics, untargeted metabolomics and lipidomics, to demonstrate that the pAKT2 Ser128 and pCCTα Ser315/319/323-positive cancer-associated fibroblasts (CAFs) substantially release phosphatidylcholines (PCs), contributing to the resistance of focal adhesion kinase (FAK) inhibitors in esophageal squamous cell carcinoma (ESCC) treatment. Additionally, we observed extremely low levels of FAK Tyr397 expression in CAFs, potentially offering no available target for FAK inhibitors playing their anti-growth role in CAFs. Consequently, FAK inhibitor increased the intracellular concentration of Ca2+ in CAFs, promoting the formation of AKT2/CCTα complex, leading to phosphorylation of CCTα Ser315/319/323 sites and eventually enhancing stromal PC production. This activation could stimulate the intratumoral Janus kinase 2 (JAK2)/Signal transducer and activator of transcription 3 (STAT3) pathway, triggering resistance to FAK inhibition. Analysis of clinical samples demonstrated that stromal pAKT2 Ser128 and pCCTα Ser315/319/323 are related to the tumor malignancy and reduced patient survival. Pseudo-targeted lipidomics and further validation cohort quantitatively showed that plasma PCs enable to distinguish the malignant extent of ESCC patients. In conclusion, inhibition of stroma-derived PCs and related pathway could be possible therapeutic strategies for tumor therapy.

Abstract PR07: Unravelling the epigenetic landscape of pancreatic cancer: The role of cancer-associated fibroblasts

Abstract Pancreatic cancer is set to become the 3rd deadliest cancer by 2025. Pancreatic ductal adenocarcinoma (PDAC) represents the majority of cases and is the most aggressive subtype, with a 5-year survival rate of around 10% and patients often diagnosed at a metastatic stage. Current treatments offer dismal survival benefit for the patients, highlighting the need for innovative therapeutic strategies. PDAC is characterized by genetic and epigenetic modifications and an abundant tumor microenvironment (TME) largely composed of cancer-associated fibroblasts (CAFs). Multiple populations of CAFs have been described and implicated in PDAC progression, however, little is known regarding the molecular crosstalk between them and the cancer cells. This project aims to investigate how the epigenetic landscape of PDAC is affected by recently described CAF populations. We have optimized a co-culture model consisting of cancer cells and genetically-locked inflammatory CAFs (iCAFs) and myofibroblastic CAFs (myCAFs) to study the link between the TME and the gene regulatory machinery in PDAC through proteomic and genomic approaches. Firstly, a full proteome analysis revealed the two CAF populations drive expression of different subsets of proteins in PDAC cells, including transcription factors. We then interrogated chromatin accessibility via ATAC-seq, which showed that CAF subsets differentially affect chromatin dynamics in epithelial cells. Transcription factor interactomes were investigated using rapid immunoprecipitation of endogenous proteins (RIME), a method developed in our lab that allows the discovery of protein complexes in a robust manner. We leverage this technique to discover druggable transcription factor interactors. RIME data shows that upon co-culture with each CAF population, distinct interactors are recruited towards FOXA1, a pioneer factor that drives a transcriptional program associated with PDAC metastasis to the liver, and towards FOXA2, which has been shown to play distinct roles in different grades of PDAC. We are now assessing the potential of these interactors as drug candidates in each context. Chromatin immunoprecipitation assays have shown that the CAF populations also affect the binding profile of FOXA1 and FOXA2 to the chromatin. We are currently investigating how CAFs impact tumor progression in vivo using an orthotopic implantation model. Preliminary data suggests that CAF subsets affect the metastatic profile in PDAC, as tumors co-injected with iCAFs metastasize to different organs than those co-injected with myCAFs. Ongoing experiments aim to explore the differences between tumors and metastases at the epigenetic level. Subsequent studies will aim to employ distinct approaches that target tumor progression in each context. PDAC is a highly heterogeneous cancer with several layers of complexity; therefore, a more holistic approach is critical to tackle the disease. Understanding tumor-stroma interactions from an epigenetics standpoint may enable identification of druggable molecules much needed for PDAC patients. Citation Format: Catarina Pelicano, Igor Chernukhin, Lisa Young, Naomi Vranas, Yi Cheng, Joshua Kent, Kamal Kishore, Clive D'Santos, Alasdair Russell, Giulia Biffi, Shalivi V. Rao, Jason S. Carroll. Unravelling the epigenetic landscape of pancreatic cancer: The role of cancer-associated fibroblasts [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr PR07.

Abstract IA20: Stromal-derived NRG1 enables oncogenic KRAS bypass in pancreas cancer

Abstract Oncogenic KRAS (KRAS*) is a signature mutation in pancreatic ductal adenocarcinoma (PDAC). While genetic extinction or pharmacological inhibition of KRAS* elicits anti-tumor responses in preclinical models and patients, we and others have identified cancer cell intrinsic (YAP, RTKs) and paracrine immune-mediated (TGFb) mechanisms enabling KRAS* bypass and tumor recurrence. Here, we explored the potential role of cancer associated fibroblasts (CAFs) as contributors to mechanisms driving KRAS* bypass and identified CAF-derived NRG1 activation of cancer cell ERBB2 and ERBB3 receptor tyrosine kinases as a mechanism by which KRAS* independent tumor regrowth is supported. We showed that genetic extinction or pharmacological inhibition of KRAS* results in upregulation of ERBB2 and ERBB3 expression in human and murine cancer cell models. We demonstrated that CAF-derived NRG1 supports KRAS*-dependent tumor growth. These insights prompted genetic depletion or pharmacological inhibitions studies targeting ERBB2/3 or NRG1, which showed abolition of KRAS* bypass and synergy with KRASG12D inhibitor in mouse and human PDAC models. Thus, CAFs via the NRG-ERBB2/3 paracrine axis provide yet another mechanism enabling KRAS* inhibitor therapy resistance, providing a highly actionable combination therapeutic strategy to improve the effectiveness of KRAS* inhibitors in PDAC patients. Citation Format: Jincheng Han, Jiaqian Xu, Yonghong Liu, Shaoheng Liang, Kyle A. LaBella, Deepavali Chakravarti, Denise J. Spring, Yan Xia, Ronald A. DePinho. Stromal-derived NRG1 enables oncogenic KRAS bypass in pancreas cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr IA20.

Mapping knowledge structure and themes trends of cancer-associated fibroblasts: a text-mining study.

Introduction: Cancer-associated fibroblasts (CAFs) constitute an important component of the tumor microenvironment, participating in various facets of cancer advancement and being recognized as contributors to tumor immune evasion. The role of CAFs in various tumor types has attracted increasing attention recently. In this work, we conducted a comprehensive bibliometric analysis to uncover research trajectories and highlight emerging areas in the field of CAFs. Methods: A systematic search was performed within the Web of Science Core Collection to identify articles/reviews on CAFs published between 2000 and 2023. Leveraging advanced bibliometric tools such as VOSviewer, CiteSpace, and online website, we examined and visualized publication trends, geographic contributions, institutional affiliations, journal prominence, author collaborations, and noteworthy references, keywords, and genes. Results: Our analysis included 5,190 publications, indicating a rapid growth trend in both annual publications and citations related to CAFs. China and the United States emerged as the foremost contributors in terms of publications, funding agencies, and international collaborations. Breast cancer was the most studied tumor, followed by colorectal cancer, pancreatic cancer, prostate cancer, and gastric cancer. Based on co-occurrence and bursting keywords, we identified the following research topics including immune cells (T cells, B-cells, tumor-associated macrophages), tumor immune microenvironment (antitumor immunity, immune infiltration, immunosuppression), immunotherapy (PD-L1), microRNAs (miRNA), extracellular vesicles (exosome), multiple tumors (pancreatic ductal adenocarcinoma, bladder cancer, head and neck squamous cell carcinoma), antitumor agents (gemcitabine, cisplatin resistance), bioinformatics (pan-cancer), epithelial-mesenchymal transition (stemness), FAPI PET/CT, DNA methylation, etc., may receive sustained attention in the future. Furthermore, TGFB1, IL-6, TNF, TP53, and VEGFA emerged as the top 5 genes that have garnered the greatest research attention in the field of CAFs. The KEGG enrichment analysis highlighted that the top 20 most studied genes were mainly associated with HIF-1 and Toll-like receptor signaling pathways. Discussion: In sum, our bibliometric analysis offers a comprehensive overview of the research landscape in the field of CAFs. It encompasses the current state, evolving patterns, and prospective avenues of exploration, with special attention to the potential advancements in tumor immune microenvironment.

Unraveling the Role and Spatial Architecture of Cancer-Associated Fibroblasts in Classical Hodgkin Lymphoma

Introduction: Cancer-associated fibroblasts (CAFs) constitute an important stromal component of the tumor microenvironment (TME). They are a heterogeneous population of cells, which can modulate the immune system and have both pro-tumorigenic and anti-tumorigenic effects in a context-dependent manner. In solid tumors, the impact of CAFs in shaping the TME is well recognized, although challenges, including lack of specific CAF markers, still exist. In classical Hodgkin lymphoma (cHL), the role of CAFs has remained largely undefined. Here, we aimed to characterize distinct CAF subsets as well as their interactions with other TME cells and associate the findings with clinical characteristics and outcome of patients with previously untreated cHL. Methods: We used a tissue microarray (TMA) containing formalin-fixed paraffin-embedded samples from 115 diagnostic cHL tumors. The TMA was stained with a 7-plex immunohistochemistry panel to characterize CAFs [platelet-derived growth factor (PDGFR) -alpha and -beta, fibroblast-activating protein (FAP), secreted protein acidic and rich in cysteine (SPARC)], macrophages (CD68), Hodgkin-Reed Sternberg (HRS) cells (CD30), and leukocytes (CD45). Image processing and quality control were performed by combining Ilastik and CellProfiler softwares, and nuclei segmented by a pretrained deep learning segmentation model. Single cell features from the images were extracted using HistoCAT software. We utilized the Phenograph clustering algorithm for cell phenotyping and a permutation test by HistoCAT for neighborhood analysis. Results: We identified a total of 952,099 single cells, which were split into 25 distinct phenotype subsets by the Phenograph clustering spanning CAFs, macrophages, leukocytes, and HRS cells. CAFs were classified into seven distinct subsets based on the status of the different CAF markers. Median proportion of all CAFs was 28% (range 2-80%), the proportion being higher in the nodular sclerosis subtype compared to the others. In general, higher proportions of CAFs associated with favorable freedom from treatment failure (FFTF) independently of the subtype, age, and stage (P<0.01). On the contrary, a subcluster of CD45+ immune cells with strong FAP-positivity, which were characterized as macrophages, was enriched in other than nodular sclerosis subtype (P<0.001) and associated with worse FFTF independently of age, stage, and subtype (P=0.01). The neighborhood analysis allowed identification of colocalization and statistically significant interaction or avoidance between pairs of cell phenotypes. For instance, higher proportions of FAP+PDGFRalpha+ CAFs interacting with other cells predicted better FFTF (P<0.01), whereas interactions of FAP+ macrophages with other cells were associated with worse FFTF. Despite the positive impact of CAF proportions on cHL outcome, patients with CD30+ HRS cells surrounded by PDGFRbeta+ CAFs had worse FFTF (P<0.001). Conclusions: We have characterized distinct CAF subsets in cHL and demonstrate their favorable clinical impact on cHL outcome. We also identified a novel subset of FAP-positive macrophages, the proportions and interactions of which translated to poor outcome. Our data highlight that not only the cell proportions, but the cell-cell interactions and spatial context play a crucial role. Further validation of the findings is ongoing.

Role of cancer-associated fibroblasts in the progression, therapeutic resistance and targeted therapy of oesophageal squamous cell carcinoma.

Oesophageal squamous cell carcinoma (ESCC) is one of the most aggressive malignant tumours with high morbidity and mortality. Although surgery, radiotherapy and chemotherapy are common treatment options available for oesophageal cancer, the 5-year survival rate remains low after treatment. On the one hand, many oesophageal cancers are are discovered at an advanced stage and, on the other hand, treatment resistance is a major obstacle to treating locally advanced ESCC. Cancer-associated fibroblasts (CAFs), the main type of stromal cell in the tumour microenvironment, enhance tumour progression and treatment resistance and have emerged as a major focus of study on targeted therapy of oesophageal cancer.With the aim of providing potential, prospective targets for improving therapeutic efficacy, this review summarises the origin and activation of CAFs and their specific role in regulating tumour progression and treatment resistance in ESCC. We also emphasize the clinical potential and emerging trends of ESCC CAFs-targeted treatments.

Role of cancer-associated fibroblasts in colorectal cancer and their potential as therapeutic targets

Cancer-associated fibroblasts (CAFs) are mesenchymal cells in the tumor microenvironment (TME). CAFs are the most abundant cellular components in the TME of solid tumors. They affect the progression and course of chemotherapy and radiotherapy in various types of tumors including colorectal cancer (CRC). CAFs can promote tumor proliferation, invasion, and metastasis; protect tumor cells from immune surveillance; and resist tumor cell apoptosis caused by chemotherapy, resulting in drug resistance to chemotherapy. In recent years, researchers have become increasingly interested CAF functions and have conducted extensive research. However, compared to other types of malignancies, our understanding of the interaction between CRC cells and CAFs remains limited. Therefore, we searched the relevant literature published in the past 10 years, and reviewed the origin, biological characteristics, heterogeneity, role in the TME, and potential therapeutic targets of CAFs, to aid future research on CAFs and tumors.

FNIII14 Peptide-Enriched Membrane Nanocarrier to Disrupt Stromal Barriers through Reversing CAFs for Augmenting Drug Penetration in Tumors.

Given the key roles of cancer associated fibroblasts (CAFs) in shaping tumor stroma, this study shows a CAF-associated ITGB1-inactivating peptide-enriched membrane nanodelivery system (designated as PMNPs-D) to simultaneously target CAFs and tumor cells for boosted chemotherapy through promoted drug perfusion. In the structure of PMNPs-D, the PLGA-based inner core is loaded with the chemotherapeutic drug doxorubicin, and the outer surface is cloaked by hybrid biomembranes with the insertion of integrin β1 (ITGB1) inhibiting peptide (i.e., FNIII14). After prolonged blood circulation and actively targeting in tumor sites, PMNPs-D can respond to CAF-overexpressed fibroblast activation protein-α (FAP-α) to trigger the release of FNIII14, which will bind to ITGB1 and inhibit CAFs' biological function in producing the stromal matrix, thereby loosening the condensed stromal structure and enhancing the permeability of nanotherapeutics in tumors. As a result, this tailor-designed nanosystem shows substantial tumor inhibition and metastasis retardation in aggressive adenoid cystic carcinoma (ACC) tumor-harboring mice.

Cancer-associated fibroblasts in hematologic malignancies: elucidating roles and spotlighting therapeutic targets.

Hematologic malignancies comprise a diverse range of blood, bone marrow, and organ-related disorders that present significant challenges due to drug resistance, relapse, and treatment failure. Cancer-associated fibroblasts (CAFs) represent a critical component of the tumor microenvironment (TME) and have recently emerged as potential therapeutic targets. In this comprehensive review, we summarize the latest findings on the roles of CAFs in various hematologic malignancies, including acute leukemia, multiple myeloma, chronic lymphocytic leukemia, myeloproliferative neoplasms, and lymphoma. We also explore their involvement in tumor progression, drug resistance, and the various signaling pathways implicated in their activation and function. While the underlying mechanisms and the existence of multiple CAF subtypes pose challenges, targeting CAFs and their associated pathways offers a promising avenue for the development of innovative treatments to improve patient outcomes in hematologic malignancies.

Cancer-associated fibroblasts: Mediators of head and neck tumor microenvironment remodeling.

Cancer-associated fibroblasts (CAFs) are involved in critical aspects of head and neck squamous cell carcinoma (HNSCC) pathogenesis, such as the formation of a tumor-permissive extracellular matrix structure, angiogenesis, or immune and metabolic reprogramming of the tumor microenvironment (TME), with implications for metastasis and resistance to radiotherapy and chemotherapy. The pleiotropic effect of CAFs in TME is likely to reflect the heterogeneity and plasticity of their population, with context-dependent effects on carcinogenesis. The specific properties of CAFs provide many targetable molecules that could play an important role in the future therapy of HNSCC. In this review article, we will focus on the role of CAFs in the TME of HNSCC tumors. We will also discuss clinically relevant agents targeting CAFs, their signals, and signaling pathways, which are activated by CAFs in cancer cells, with the potential for repurposing for HNSCC therapy.

Microdissection of cancer-associated fibroblast infiltration subtypes unveils the secreted SERPINE2 contributing to immunosuppressive microenvironment and immuotherapeutic resistance in gastric cancer: A large-scale study integrating bulk and single-cell transcriptome profiling

In the era of immunotherapy, the suboptimal response rate and the development of acquired resistance among the initial beneficiaries continue to present significant challenges across multiple malignancies, including gastric cancer (GC). Considering that the interactions of tumor stroma, especially the cancer-associated fibroblasts (CAFs), with immune and tumor cells, play indispensable roles in tumor progression, tumor microenvironment remodeling and therapeutic responsiveness, in-depth exploration on the roles of CAFs and pivotal mediators of their functions may provide novel clues to increase the effectiveness of current immunotherapeutic drugs and further achieve synergistic antitumor response. Herein, through the consensus clustering of canonical biomarkers, three GC subclasses with different abundance of CAFs were virtually microdissected in four integrated bulk cohorts encompassing 2148 GC patients from 11 independent datasets. An extensive immunogenomic analysis revealed that tumors with high CAFs infiltration were characterized with unfavorable outcomes, aggressive phenotypes, decreased tumor immunogenicity, high risk of immune evasion and thus immunotherapeutic resistance. By leveraging large-scale single-cell transcriptomic profiling, a series of CAF-secreted proteins were identified, among which the SERPINE2 was confirmed to be restrictively enriched in stromal fibroblasts of GC tissues and contribute to promoting a protumor milieu and fostering an immunosuppressive microenvironment via bioinformatics computations and tissue microarray analysis. Moreover, pan-cancer investigations generalized the immunological roles of SERPINE2, especially in pan-gastrointestinal malignancies, with multiple real-world immunotherapy cohorts further confirming its implications on predicting immunotherapeutic efficacy. In conclusion, these findings suggest that the CAF-derived SERPINE2 is a promising immune-oncology target with therapeutic implications to further synergize the immunotherapeutic combinations.

Cancer-associated fibroblasts promote venous thrombosis through podoplanin/CLEC-2 interaction in podoplanin-negative lung cancer mouse model

BackgroundCancer-associated thrombosis (CAT) is the leading cause of morbidity and mortality. Cancer-associated fibroblasts (CAFs) are a prominent component of the tumor microenvironment that contributes to cancer progression through direct cell–cell interactions and the release of extracellular vesicles (EVs). However, the role of CAFs in CAT remains unclear. ObjectiveThis study aims to investigate whether CAFs aggravate CAT and the underlying molecular mechanism using a preclinical mouse lung cancer model. MethodsWe designed a Lewis lung carcinoma (LLC) tumor-bearing mouse model. CAFs were characterized using fluorescence immunohistostaining. The presence of podoplanin, a platelet-activating membrane protein through C-type lectin-like receptor 2 (CLEC-2), in EVs isolated from primary CAFs or LLC tumor tissues was assessed by immunoblotting. The platelet activation and aggregation abilities of the EVs were quantified using flow cytometry. Podoplanin plasma levels were measured by enzyme-linked immunosorbent assay. Venous thrombosis was induced in the femoral vein using 2.5% ferric chloride. The anti-CLEC-2 monoclonal antibody 2A2B10 was used to deplete CLEC-2 on the surface of the platelets. ResultsCAFs expressing CD90, PDGFRβ, HSP47, CD34, and vimentin, co-expressed podoplanin and induced platelet activation and aggregation in a CLEC-2-dependent manner. Tumor-bearing mice showed elevated podoplanin plasma levels. CAF-EV injection and tumor-bearing mice showed shorter occlusion time in the venous thrombosis model. Although tumor growth was not altered, antibody-induced CLEC-2 depletion suppressed venous thrombosis in the tumor-bearing state but not in the healthy condition. ConclusionCAFs and CAF-derived EVs induce CLEC-2-dependent platelet aggregation and aggravate venous thrombosis.

The role of cancer-associated fibroblasts in breast cancer metastasis.

Breast cancer deaths are primarily caused by metastasis. There are several treatment options that can be used to treat breast cancer. There are, however, a limited number of treatments that can either prevent or inhibit the spread of breast tumor metastases. Thus, novel therapeutic strategies are needed. Studies have increasingly focused on the importance of the tumor microenvironment (TME) in metastasis of breast cancer. As the most abundant cells in the TME, cancer-associated fibroblasts (CAFs) play important roles in cancer pathogenesis. They can remodel the structure of the extracellular matrix (ECM) and engage in crosstalk with cancer cells or other stroma cells by secreting growth factors, cytokines, and chemokines, as well as components of the ECM, which assist the tumor cells to invade through the TME and cause distant metastasis. Clinically, CAFs not only foster the initiation, growth, angiogenesis, invasion, and metastasis of breast cancer but also serve as biomarkers for diagnosis, therapy, and prediction of prognosis. In this review, we summarize the biological characteristics and subtypes of CAFs and their functions in breast cancer metastasis, focusing on their important roles in the diagnosis, prognosis, and treatment of breast cancer. Recent studies suggest that CAFs are vital partners of breast cancer cells that assist metastasis and may represent ideal targets for prevention and treatment of breast cancer metastasis.

Single-cell RNA sequencing reveals cell subpopulations in the tumor microenvironment contributing to hepatocellular carcinoma.

Background: Hepatocellular carcinoma (HCC) is among the deadliest cancers worldwide, and advanced HCC is difficult to treat. Identifying specific cell subpopulations in the tumor microenvironment and exploring interactions between the cells and their environment are crucial for understanding the development, prognosis, and treatment of tumors. Methods: In this study, we constructed a tumor ecological landscape of 14 patients with HCC from 43 tumor tissue samples and 14 adjacent control samples. We used bioinformatics analysis to reveal cell subpopulations with potentially specific functions in the tumor microenvironment and to explore the interactions between tumor cells and the tumor microenvironment. Results: Immune cell infiltration was evident in the tumor tissues, and BTG1 + RGS1 + central memory T cells (Tcms) interact with tumor cells through CCL5-SDC4/1 axis. HSPA1B may be associated with remodeling of the tumor ecological niche in HCC. Cancer-associated fibroblasts (CAFs) and macrophages (TAMs) were closely associated with tumor cells. APOC1 + SPP1 + TAM secretes SPP1, which binds to ITGF1 secreted by CAFs to remodel the tumor microenvironment. More interestingly, FAP + CAF interacts with naïve T cells via the CXCL12-CXCR4 axis, which may lead to resistance to immune checkpoint inhibitor therapy. Conclusion: Our study suggests the presence of tumor cells with drug-resistant potential in the HCC microenvironment. Among non-tumor cells, high NDUFA4L2 expression in fibroblasts may promote tumor progression, while high HSPA1B expression in central memory T cells may exert anti-tumor effects. In addition, the CCL5-SDC4/1 interaction between BTG1 + RGS1 + Tcms and tumor cells may promote tumor progression. Focusing on the roles of CAFs and TAMs, which are closely related to tumor cells, in tumors would be beneficial to the progress of systemic therapy research.

The Androgen Regulation of Matrix Metalloproteases in Prostate Cancer and Its Related Tumor Microenvironment

Prostate cancer represents the most common type of cancer among males and the second leading cause of cancer death in men in Western society. In most cases (~70%), PC has a slow and symptom-free growth, whereas it is more aggressive in the remaining patients. Current PC therapies prevalently target the proliferative function of the androgen receptor and may only be effective within short periods, beyond which the disease will progress to metastatic and castration-resistant phenotype. Preclinical and clinical studies are aimed at investigating the molecular basis for prostate cancer spreading. Although considerable efforts have been made to dissect the programs that foster prostate cancer spreading, few biomarkers predictive of metastatic phenotype have yet been identified and few therapeutic options are available for treatment of the metastatic disease. In the present paper, we will discuss innovative aspects of prostate cancer biology, which impinge on the role of cancer-associated fibroblasts and the released matrix metalloproteinases in the disease progression. Investigating these aspects might allow the discovery of clinically actionable biomarkers to target in the advanced stages of prostate cancer.