Cancer-associated Fibroblasts Activation Research Articles

Adipose-Derived Stromal Cells and Cancer-Associated Fibroblasts: Interactions and Implications in Tumor Progression

Adipose-derived stromal cells (ASCs) and cancer-associated fibroblasts (CAFs) play pivotal roles in the tumor microenvironment (TME), significantly influencing cancer progression and metastasis. This review explores the plasticity of ASCs, which can transdifferentiate into CAFs under the influence of tumor-derived signals, thus enhancing their secretion of extracellular matrix components and pro-inflammatory cytokines that promote tumorigenesis. We discuss the critical process of the epithelial-to-mesenchymal transition (EMT) facilitated by ASCs and CAFs, highlighting its implications for increased invasiveness and therapeutic resistance in cancer cells. Key signaling pathways, including the transforming growth factor-β (TGF-β), Wnt/β-catenin, and Notch, are examined for their roles in regulating EMT and CAF activation. Furthermore, we address the impact of epigenetic modifications on ASC and CAF functionality, emphasizing recent advances in targeting these modifications to inhibit their pro-tumorigenic effects. This review also considers the metabolic reprogramming of ASCs and CAFs, which supports their tumor-promoting activities through enhanced glycolytic activity and lactate production. Finally, we outline potential therapeutic strategies aimed at disrupting the interactions between ASCs, CAFs, and tumor cells, including targeted inhibitors of key signaling pathways and innovative immunotherapy approaches. By understanding the complex roles of ASCs and CAFs within the TME, this review aims to identify new therapeutic opportunities that could improve patient outcomes in cancer treatment.

Decoding tumor-fibrosis interplay: mechanisms, impact on progression, and innovative therapeutic strategies

Malignant tumors are a category of diseases that possess invasive and metastatic capabilities, with global incidence and mortality rates remaining high. In recent years, the pivotal role of fibrosis in tumor progression, drug resistance, and immune evasion has increasingly been acknowledged. Fibrosis enhances the proliferation, migration, and invasion of tumor cells by modifying the composition and structure of the extracellular matrix, thereby offering protection for immune evasion by tumor cells. The activation of cancer-associated fibroblasts (CAFs) plays a significant role in this process, as they further exacerbate the malignant traits of tumors by secreting a variety of cytokines and growth factors. Anti-fibrotic tumor treatment strategies, including the use of anti-fibrotic drugs and inhibition of fibrosis-related signaling pathways such as Transforming Growth Factor-β (TGF-β), have demonstrated potential in delaying tumor progression and improving the effectiveness of chemotherapy, targeted therapy, and immunotherapy. In the future, by developing novel drugs that target the fibrotic microenvironment, new therapeutic options may be available for patients with various refractory tumors.

The use of a multi-metric readout screen to identify EHMT2/G9a-inhibition as a modulator of cancer-associated fibroblast activation state

Cancer-associated fibroblasts (CAFs) play a pivotal role in cancer progression, including mediating tumour cell invasion via their pro-invasive secretory profile and ability to remodel the extracellular matrix (ECM). Given that reduced CAF abundance in tumours correlates with improved outcomes in various cancers, we set out to identify epigenetic targets involved in CAF activation in regions of tumour-stromal mixing with the goal of reducing tumour aggressiveness. Using the GLAnCE (Gels for Live Analysis of Compartmentalized Environments) platform, we performed an image-based, phenotypic screen that enabled us to identify modulators of CAF abundance and the capacity of CAFs to induce tumour cell invasion. We identified EHMT2 (also known as G9a), an enzyme that targets the methylation of histone 3 lysine 9 (H3K9), as a potent modulator of CAF abundance and CAF-mediated tumour cell invasion. Transcriptomic and functional analysis of EHMT2-inhibited CAFs revealed EHMT2 participated in driving CAFs towards a pro-invasive phenotype and mediated CAF hyperproliferation, a feature typically associated with activated fibroblasts in tumours. Our study suggests that EHMT2 regulates CAF state within the tumour microenvironment by impacting CAF activation, as well as by magnifying the pro-invasive effects of these activated CAFs on tumour cell invasion through promoting CAF hyperproliferation.

MIR4435-2HG: A novel biomarker for triple-negative breast cancer diagnosis and prognosis, activating cancer-associated fibroblasts and driving tumor invasion through EMT associated with JNK/c-Jun and p38 MAPK signaling pathway activation

BackgroundBreast cancer has the highest incidence rate and causes the most fatalities among all female cancers worldwide. Triple-negative breast cancer (TNBC) is known for its strong invasiveness and higher rates of recurrence. In this research, we aimed to identify MIR4435-2HG as a promising long non-coding RNA (lncRNA) biomarker and therapeutic target for TNBC. MethodsUtilizing clinicopathological information and transcriptome data from The Cancer Genome Atlas (TCGA) database, we assessed the clinical relevance of MIR4435-2HG in breast cancer through univariate and multivariate COX regression, receiver operating characteristic (ROC) analysis, as well as Kaplan-Meier survival analysis. To investigate the biological role of MIR4435-2HG in TNBC, we conducted gene set enrichment analysis (GSEA), as well as Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Additionally, we constructed and validated a nomogram to predict disease-free survival (DFS). Both the R package “pRRophetic” and the Tumor Immune Dysfunction and Exclusion (TIDE) algorithm were employed to forecast the sensitivity to different therapeutics between the high- and low-MIR4435-2HG groups. We employed single-cell RNA sequencing analysis and tumor microenvironment infiltration analysis to investigate the potential involvement of MIR4435-2HG in the TNBC tumor microenvironment. Cellular biological behaviors were assessed utilizing CCK-8, transwell assays, and wound-healing assays. Furthermore, we performed RNA-seq, qRT-PCR, and western blotting analyses to elucidate and confirm the specific mechanisms underlying the role of MIR4435-2HG in TNBC. ResultsIn our study, we have identified MIR4435-2HG as a significant diagnostic and prognostic factor for TNBC. We observed that MIR4435-2HG is widely expressed and might have a significant impact on the reshaping of the TNBC tumor microenvironment. Patients with TNBC in the high-MIR4435-2HG group may show reduced sensitivity to cisplatin, doxorubicin, and gemcitabine and have an increased propensity for immune escape. Knockdown of MIR4435-2HG inhibits cancer-associated fibroblasts (CAFs) activation. Notably, MIR4435-2HG predominantly enhances the migratory and invasive capabilities of TNBC cells through the epithelial-mesenchymal transition (EMT) process. Mechanistically, we validated that MIR4435-2HG activates the JNK/c-Jun and p38 non-classical MAPK signaling pathway in TNBC cells. ConclusionsOur findings highlight the significant potential of MIR4435-2HG as a highly promising biomarker for TNBC. Targeting MIR4435-2HG could represent an appealing therapeutic approach for TNBC.

Abstract C010: Single-cell profiling unleashes KRAS-driven redrafting of the tumor microenvironment before cancer onset

Abstract Pancreatic cancer is a highly lethal and aggressive disease, commonly characterized by a unique tumor microenvironment, where mutant KRAS signaling plays a pivotal role in its pathophysiology. To deepen our understanding of KRAS-dependent signaling in earliest tumor development, oncogenic KRAS (KRASG12D) expression was induced in human stem cell-derived pancreatic ductal-like organoids (PDLOs), followed by time-resolved single-cell RNA and bulk ATAC sequencing. This unique precancerous state model facilitated a comprehensive characterization of early oncogenic events at cellular resolution. Furthermore, a machine learning approach was applied to accurately predict KRAS-dependent cell identities. Within seven days, mutated KRAS triggers distinct gene signature programs related to extracellular matrix remodeling and inflammation. Although derived from dysplastic yet non-cancerous states, these gene signatures negatively correlated with overall survival in PDAC (pancreatic ductal adenocarcinoma) patients. The KRAS-dependent signatures retrieved with the machine learning approach allowed the grouping of 24 published PDAC cases, showing differences in niche composition and communication patterns. Various co-culture systems demonstrated that KRASG12D-expressing PDLOs could activate pancreatic stellate cells, inducing a cancer- associated fibroblast (CAF)-like state. Simultaneously, these KRAS-activated organoids were protected from T cell infiltration in vitro. Furthermore, in silico approaches were employed to reconstruct a virtual pancreatic cancer space, demonstrating that our PDLOs transcriptionally bridge healthy and malignant ductal states. This also revealed potential KRAS-driven pathways mediating CAF activation and T cell shielding preceding cancer onset. In summary, our human PDLO model enables us to explore the transition from normal to cancerous states, addressing gaps in our understanding of tumor development and tumor niche preparation. Citation Format: Chantal Allgoewer, Markus Breunig, Meike Hohwieler, Medhanie Mulaw, Alexander Kleger. Single-cell profiling unleashes KRAS-driven redrafting of the tumor microenvironment before cancer onset [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C010.

Abstract A053: Interrogating the spatial biology of pancreatic cancer-associated fibroblasts in resected human pancreatic cancer

Abstract Introduction Cancer-associated fibroblasts (CAFs) are key players in the fibrotic tumour microenvironment (TME) of pancreatic cancer. Recent evidence has demonstrated the existence of multiple CAF subtypes, however there is relatively little evidence validating and corroborating these CAF subtypes in resected human pancreatic cancer. Furthermore, the spatial interactions between CAF subtypes and the epithelial and immune compartments of the pancreatic cancer TME is not well understood. Methods We designed and optimised a bespoke 8-plex immunofluorescence panel for the purposes of CAF subtype profiling and elucidation of CAF spatial biology: panCK, FAP, SMA, CTGF, S100A4, IL6, LIF, PDGFR. This was applied to a cohort of n=215 resected pancreatic cancer, well characterised with highly granular clinico-pathological and transcriptomic data through the Australian Pancreatic Cancer Genome Initiative. Spatial analysis was performed with novel computational biology techniques. Results We demonstrate seven CAF subtypes which cluster to form distinct, highly prognostic “enrichment profiles” (EPs). The cold EP represents quiescent CAFs in close proximity to immune cells (multivariate HR 0.45, 95% CI 0.30-0.68, p<0.001), and the fibrotic EP represents activated CAFs in close proximity to epithelial cells (multivariate HR 2.22, 95% CI 1.48-3.35, p<0.001). We also demonstrate the prognostic power of high spatial entropy (loss of tissue architecture, correlating with the fibrotic EP) vs low spatial entropy (preservation of tissue architecture, correlating with the cold EP) (HR 2.22, 95% CI 1.47-3.35, p<0.001). Conclusion We begin to unravel the elusive spatial biology of pancreatic CAFs in a large resected human cohort. We see changes in immune cell infiltrate, modulation of cellular relationships, and greater tissue disorganisation as a result of CAF activation. These features are highly prognostic and we hypothesise they are driven by changes in crosstalk between TME compartments. Current work focuses on application of these techniques to a large resected neoadjuvantly-treated cohort, allowing further interrogation of the notorious fibrotic post-neoadjuvant pancreatic cancer TME. If accepted for presentation we look forward to presenting both cohorts simultaneously. Citation Format: Adam Bryce, Stephan Dreyer, Fieke Froeling, Silvia Martinelli, Rachel Pennie, Leah Officer-Jones, John Le Quesne, David Chang. Interrogating the spatial biology of pancreatic cancer-associated fibroblasts in resected human pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A053.

Nuclear lamin A/C phosphorylation by loss of androgen receptor leads to cancer-associated fibroblast activation

Alterations in nuclear structure and function are hallmarks of cancer cells. Little is known about these changes in Cancer-Associated Fibroblasts (CAFs), crucial components of the tumor microenvironment. Loss of the androgen receptor (AR) in human dermal fibroblasts (HDFs), which triggers early steps of CAF activation, leads to nuclear membrane changes and micronuclei formation, independent of cellular senescence. Similar changes occur in established CAFs and are reversed by restoring AR activity. AR associates with nuclear lamin A/C, and its loss causes lamin A/C nucleoplasmic redistribution. AR serves as a bridge between lamin A/C and the protein phosphatase PPP1. Loss of AR decreases lamin-PPP1 association and increases lamin A/C phosphorylation at Ser 301, a characteristic of CAFs. Phosphorylated lamin A/C at Ser 301 binds to the regulatory region of CAF effector genes of the myofibroblast subtype. Expression of a lamin A/C Ser301 phosphomimetic mutant alone can transform normal fibroblasts into tumor-promoting CAFs.

The role of long non‐coding RNA Maternally Expressed Gene 3 in cancer‐associated fibroblasts at single cell pan‐cancer level

AbstractLong non‐coding RNAs (lncRNAs) can crucially regulate activation and transformation of cancer‐associated fibroblasts (CAFs) but have not been systematically investigated at single cell resolution. Here, by utilizing integrated single‐cell sequencing datasets, we screened the aberrantly expressed lncRNAs in CAFs, which are the major component of tumor microenvironment. Our findings revealed a consistent CAF‐specific downregulation of Maternally Expressed Gene 3 (MEG3) expression and increased MEG3+ proportion at the pan‐cancer level, which may be attributed to m6A‐related post‐transcriptional modifications. Through activation trajectory analysis of the major CAF subtypes, it was determined that elevated MEG3 expression in CAFs leads to an increase in PDGFRA expression. This, in turn, promotes CAF activation and transformation into an MEG3+ adipogenic CAF (MACAF) subtype, which is more sensitive to Dasatinib. MACAF‐related cell–cell interactions highlighted that MACAF could enhance the epithelial‐mesenchymal transition process in tumor cells via the TGF‐β pathway, promoting tumor cell migration and possibly contributing to tumor progression and invasiveness. Notably, patients with higher MACAF scores experience unfavorable prognoses and poor response rates to checkpoint inhibitor‐based immunotherapy, suggesting a correlation between MACAF and immunosuppressive microenvironment shaping. Our findings provide novel insights of the MEG3 in CAF activation and highlight the potential value of the MACAF score for therapeutic strategies design involving Dasatinib and immunotherapy.

Chinese herbal Jianpi Jiedu formula suppressed colorectal cancer growth in vitro and in vivo via modulating hypoxia-inducible factor 1 alpha-mediated fibroblasts activation

Ethnopharmacological relevanceJianpi Jiedu Formula (JPJDF) is a traditional Chinese medicinal decoction clinically used for its anti-cancer properties, particularly in colorectal cancer (CRC). Aim of the studyThis study aims to investigate the therapeutic effects of JPJDF on CRC and elucidate its potential molecular mechanisms, with a focus on its impact on hypoxia-inducible factor 1 alpha (HIF1α) and cancer-associated fibroblasts (CAFs) both in vitro and in vivo. Materials and methodsUPLC-Q-TOF-MS was used to identify the constituents of JPJDF. A chemical-induced colorectal cancer model was established and treated with JPJDF to evaluate its effects. Tumor size was measured, and histopathological analyses were performed to examine JPJDF's regulatory potential on CRC. The functional mechanism of JPJDF was predicted through network pharmacology, molecular docking, and transcriptomics. Co-culture techniques involving CRC cells and CCD-18Co fibroblasts were used to assess JPJDF's impact on fibroblast activation. The effects of HIF1α on CAFs were evaluated using CCK-8 proliferation, clonal formation, and apoptotic assays, with differential marker expression quantified via qPCR and Western blotting. ResultsPharmacodynamic assessment demonstrated that JPJDF reduced tumor size without affecting body weight, indicating its safety in the chemical-induced murine CRC model. Network pharmacology analysis, combined with molecular docking and transcriptomics, revealed that JPJDF regulates HIF-1 signaling pathways and identified HIF1α as a potential target for JPJDF's anti-CRC effect. JPJDF effectively suppressed CRC growth in vivo by attenuating fibroblast activation, reducing α-SMA expression and POSTN secretion through HIF1α inhibition. HIF1α knockdown in CRC cells inhibited fibroblast proliferation and clonal formation, while overexpression promoted these processes. Additionally, downregulating HIF1α suppressed α-SMA and POSTN expression in fibroblasts, whereas overexpression enhanced fibroblast activation. ConclusionJPJDF emerges as a promising therapeutic candidate for inhibiting CAFs activation by targeting HIF1α, offering potential avenues for modulating fibroblast activation towards CAFs in CRC therapy.

Activin A-Targeted Therapy in Cancer: An Updated Review on Challenges and Opportunities in Clinical Translation.

Activin A (ActA) is a cytokine from the TGF-β superfamily that mediates a vast number of physiological mechanisms, mainly through the SMAD signaling pathway. Growing evidence indicates that ActA overexpression is also correlated with poor prognosis in cancer patients and several tumor characteristics, including cancer proliferation, metastasis, immunosuppression, drug resistance, cachexia, and cancer-associated fibroblast activation. As such, ActA-targeted therapy has been viewed as a potential adjuvant therapy alongside other anti-cancer modalities that may result in more efficient anti-cancer effects, such as stronger immune responses, overcoming drug resistance, reversing cachexia, etc. However, despite its interesting concept, targeting ActA is not without certain challenges and considerations. Indeed, ActA has unexpectedly shown anti-tumor effects in some cases, which might be explained by differences in the expression levels of different ActA receptors on the cell surface, activation of non-SMAD pathways, and imbalance in ActA levels. Besides, many of the current ActA antagonists lack enough specificity and, as a result, bind to non-ActA receptors as well. Furthermore, ubiquitous expression of ActA in the body can cause serious adverse effects following systemic administration. Furthermore, to address these issues, anti-ActA monoclonal antibodies and nanoparticle drug delivery systems have recently been suggested to target ActA with better precision in the affected area. In this review, first, we provide the different implications of ActA in cancer. Then, we discuss the recent insights into targeting ActA signaling as an adjuvant therapy alongside other anti-cancer modalities, as well as the possible challenges and novel opportunities on the path of clinical translation.

Bilayer 3D co‐culture platform inducing the differentiation of normal fibroblasts into cancer‐associated fibroblast like cells: New in vitro source to obtain cancer‐associated fibroblasts

AbstractThis study presents a novel in vitro bilayer 3D co‐culture platform designed to obtain cancer‐associated fibroblasts (CAFs)‐like cells. The platform consists of a bilayer hydrogel structure with a collagen/polyethylene glycol (PEG) hydrogel for fibroblasts as the upper layer and an alginate hydrogel for tumor cells as the lower layer. The platform enabled paracrine interactions between fibroblasts and cancer cells, which allowed for selective retrieval of activated fibroblasts through collagenase treatment for further study. Fibroblasts remained viable throughout the culture periods and showed enhanced proliferation when co‐cultured with cancer cells. Morphological changes in the co‐cultured fibroblasts resembling CAFs were observed, especially in the 3D microenvironment. The mRNA expression levels of CAF‐related markers were significantly upregulated in 3D, but not in 2D co‐culture. Proteomic analysis identified upregulated proteins associated with CAFs, further confirming the transformation of normal fibroblasts into CAF within the proposed 3D co‐culture platform. Moreover, co‐culture with CAF induced radio‐ and chemoresistance in pancreatic cancer cells (PANC‐1). Survival rate of cancer cells post‐irradiation and gemcitabine resistance increased significantly in the co‐culture setting, highlighting the role of CAFs in promoting cancer cell survival and therapeutic resistance. These findings would contribute to understanding molecular and phenotypic changes associated with CAF activation and provide insights into potential therapeutic strategies targeting the tumor microenvironment.

Integrated single-cell and bulk RNA sequencing analyses identify an immunotherapy nonresponse-related fibroblast signature in gastric cancer.

Factors that determine nonresponse to immune checkpoint inhibitor (ICI) remain unclear. The protumor activities of cancer-associated fibroblasts (CAFs) suggest that they are potential therapeutic targets for cancer treatment. There is, however, a lack of CAF-related signature in predicting response to immunotherapy in gastric cancer (GC). Single-cell RNA sequencing (scRNA-seq) and RNA sequencing (RNA-seq) data of GC immunotherapy were downloaded from the Gene Expression Omnibus database. Bulk RNA-seq data were obtained from The Cancer Genome Atlas. The R package 'Seurat' was used for scRNA-seq data processing. Cellular infiltration, receptor-ligand interactions, and evolutionary trajectory analysis were further explored. Differentially expressed genes affecting overall survival were obtained using the limma package. Weighted Gene Correlation Network Analysis was used to identify key modules of immunotherapy nonresponder. Prognostic model was constructed by univariate Cox and least absolute contraction and selection operator analysis using the intersection of activated fibroblast genes (AFGs) with key module genes. The differences in clinicopathological features, immune microenvironment, immunotherapy prediction, and sensitivity to small molecule agents between the high- and low-risk groups were further investigated. Based on scRNA-seq, we finally identified 20 AFGs associations with the prognosis of GC patients. AFGs' high expression levels were correlated with both poor prognosis and tumor progression. Three genes (FRZB, SPARC, and FKBP10) were identified as immunotherapy nonresponse-related fibroblast genes and used to construct the prognostic signature. This signature is an independent significant risk factor affecting the clinical outcomes of GC patients. Remarkably, there were more CD4 memory T cells, resting mast cells, and M2 macrophages infiltrating in the high-risk group, which was characterized by higher tumor immune exclusion. Moreover, patients with higher risk scores were more prone to not respond to immunotherapy but were more sensitive to various small molecule agents, such as memantine. In conclusion, this study constructed a fibroblast-associated ICI nonresponse gene signature, which could predict the response to immunotherapy. This study potentially revealed a novel way to overcome immune resistance in GC.

NNMT switches the proangiogenic phenotype of cancer-associated fibroblasts via epigenetically regulating ETS2/VEGFA axis.

Cancer-associated fibroblasts (CAFs) are known to promote angiogenesis in oral squamous cell carcinoma (OSCC). However, the epigenetic mechanisms through which CAFs facilitate angiogenesis within the tumor microenvironment are still poorly characterized. Nicotinamide N'-methyltransferase (NNMT), a member of the N-methyltransferase family, was found to be a key molecule in the activation of CAFs. This study shows that NNMT in fibroblasts contributes to angiogenesis and tumor growth through an epigenetic reprogramming-ETS2-VEGFA signaling axis in OSCC. Single-cell RNA Sequencing (scRNA-seq) analysis suggests that NNMT is mainly highly expressed in fibroblasts of head and neck squamous cell carcinoma (HNSCC). Moreover, analysis of the TCGA database and multiple immunohistochemical staining of clinical samples also identified a positive correlation between NNMT and tumor angiogenesis. This research further employed an assembled organoid model and a fibroblast-endothelial cell co-culture model to authenticate the proangiogenic ability of NNMT. At the molecular level, high expression of NNMT in CAFs was found to promote ETS2 expression by regulating H3K27 methylation level through mediating methylation deposition. Furthermore, ETS2 was verified to be an activating transcription factor of VEGFA in this study. Collectively, our findings delineate an epigenetic molecular regulatory network of angiogenesis and provide a theoretical basis for exploring new targets and clinical strategy in OSCC.

Unraveling the metastatic niche in breast cancer bone metastasis through single-cell RNA sequencing.

Breast cancer (BRCA) is characterized by a unique metastatic pattern, often presenting with bone metastasis (BoM), posing significant clinical challenges. Through the study of the immune microenvironment in BRCA BoM offer perspectives for therapeutic interventions targeting this specific metastatic manifestation of BRCA. This study employs single-cell RNA sequencing and TCGA data analysis to comprehensively compare primary tumors (PT), lymph node metastasis (LN), and BoM. Our investigation identifies a metastatic niche in BoM marked by an increased abundance of cancer-associated fibroblasts (CAFs) and reduced immune cell presence. A distinct subtype (State 1) of BRCA BoM cells associated with adverse prognosis is identified. State 1, displaying heightened stemness traits, may represent an initiation phase for BoM in BRCA. Complex cell communications involving tumor, stromal, and immune cells are revealed. Interactions of FN1, SPP1, and MDK correlate with elevated immune cells in BoM. CD46, MDK, and PTN interactions drive myofibroblast activation and proliferation, contributing to tissue remodeling. Additionally, MDK, PTN, and FN1 interactions influence FAP+ CAF activation, impacting cell adhesion and migration in BoM. These insights deepen our understanding of the metastatic niche in breast cancer BoM.

TGFβ2 Promotes the Construction of Fibrotic and Immunosuppressive Tumor Microenvironment in Pancreatic Adenocarcinoma: A Comprehensive Analysis.

Pancreatic adenocarcinoma (PAAD) was characterized by dense fibrotic stroma and immunosuppressive tumor microenvironment (TME). TGFβ signaling pathways are highly activated in human cancers. However, the role of TGFβ2 in TME of PAAD remains to be elucidated. In this study, we showed that TGFβ2 was expressed at a relatively high level in PAAD tissues or cancer cells. Moreover, its high expression predicted unfavorable prognosis. In PAAD, gene set enrichment analysis showed that TGFβ2 correlated positively with leukocyte transendothelial migration, but negatively with aerobic metabolism, including oxidative phosphorylation. Results in Tumor and Immune System Interaction Database showed that TGFβ2 correlated with the infiltration of tumor-associated macrophages (TAMs), which could be attributed to that TGFβ2 promote CCL2 expression in PAAD. Moreover, correlation analysis showed that TGFβ2 could trigger cancer-associated fibroblasts (CAFs) activation in PAAD. The drug sensitivity analysis may indicate that patients with TGFβ2 high expression have higher sensitivity to chemotherapeutics, but the sensitivity to targeted drugs is still controversial. TGFβ2 could promote expansion of CAFs and infiltration of TAMs, thus participating in the construction of a fibrotic and immunosuppressive TME in PAAD. Targeting TGFβ2 could be a promising therapeutic approach, which needs to be elucidated by clinical and experimental evidences.

Scribble Deficiency Promotes Pancreatic Ductal Adenocarcinoma Development and Metastasis.

Perturbation of cell polarity is a hallmark of pancreatic ductal adenocarcinoma (PDAC) progression. Scribble (SCRIB) is a well-characterized polarity regulator that has diverse roles in the pathogenesis of human neoplasms. To investigate the impact of SCRIB deficiency in PDAC development and progression, Scrib expression was genetically ablated in well-established mouse models of PDAC. Scrib loss in combination with KrasG12D did not influence development of pancreatic intraepithelial neoplasms in mice. However, Scrib deletion cooperated with KrasG12D and concomitant Trp53 heterozygous deletion to promote invasive PDAC and metastatic dissemination, leading to reduced overall survival. Immunohistochemical and transcriptome analyses revealed that Scrib-null tumors display a pronounced reduction of collagen content and an abundance of cancer-associated fibroblasts (CAF). Mechanistically, IL1α levels were reduced in Scrib-deficient tumors, and Scrib knockdown downregulated IL1α in mouse PDAC organoids (mPDO), which impaired CAF activation. Furthermore, Scrib loss increased YAP activation in mPDOs and established PDAC cell lines, enhancing cell survival. Clinically, SCRIB expression was decreased in human PDAC, and SCRIB mislocalization was associated with poorer patient outcome. These results indicate that SCRIB deficiency enhances cancer cell survival and remodels the tumor microenvironment to accelerate PDAC development and progression, establishing the tumor suppressor function of SCRIB in advanced pancreatic cancer. Significance: SCRIB loss promotes invasive pancreatic cancer development via both cell-autonomous and non-cell-autonomous processes and is associated with poorer outcomes, denoting SCRIB as a tumor suppressor and potential biomarker for the prediction of recurrence.

Reprogramming of normal fibroblasts into ovarian cancer-associated fibroblasts via non-vesicular paracrine signaling induces an activated fibroblast phenotype

Cancer-associated fibroblasts (CAFs) are key contributors to ovarian cancer (OC) progression and therapeutic resistance through dysregulation of the extracellular matrix (ECM). CAFs are a heterogenous population derived from different cell types through activation and reprogramming. Current studies rely on uncharacterized heterogenous primary CAFs or normal fibroblasts that fail to recapitulate CAF-like tumor behavior. Here, we present that conditioned media from ovarian cancer lines leads to an increase in the activated state of fibroblasts demonstrated by functional assays and up-regulation of known CAF-related genes and ECM pathways. Phenotypic and functional characterization demonstrated that the conditioned CAFs expressed a CAF-like phenotype, strengthened proliferation, secretory, contractility, and ECM remodeling properties when compared to resting normal fibroblasts, consistent with an activated fibroblast status. Moreover, conditioned CAFs significantly enhanced drug resistance and tumor progression. Critically, the conditioned CAFs resemble a transcriptional signature with involvement of ECM remodeling. The present study provides mechanistic and functional insights about the activation and reprogramming of CAFs in the ovarian tumor microenvironment mediated by non-vesicular paracrine signaling. Moreover, it provides a translational based approach to reprogram normal fibroblasts from both uterine and ovarian origin into CAFs using tumor-derived conditioned media. Using these resources, further development of therapeutics that possess potentiality and specificity towards CAF/ECM-mediated chemoresistance in OC are further warranted.

Effect of Bioactive Black Phosphorus Nanomaterials on Cancer-Associated Fibroblast Heterogeneity in Pancreatic Cancer.

Tumor-stromal interactions and stromal heterogeneity in the tumor microenvironment are critical factors that influence the progression, metastasis, and chemoresistance of pancreatic ductal adenocarcinoma (PDAC). Here, we used spatial transcriptome technology to profile the gene expression landscape of primary PDAC and liver metastatic PDAC after bioactive black phosphorus nanomaterial (bioactive BP) treatment using a murine model of PDAC (LSL-KrasG12D/+; LSL-Trp53R172H/+; and Pdx-1-Cre mice). Bioinformatic and biochemical analyses showed that bioactive BP contributes to the tumor-stromal interplay by suppressing cancer-associated fibroblast (CAF) activation. Our results showed that bioactive BP contributes to CAF heterogeneity by decreasing the amount of inflammatory CAFs and myofibroblastic CAFs, two CAF subpopulations. Our study demonstrates the influence of bioactive BP on tumor-stromal interactions and CAF heterogeneity and suggests bioactive BP as a potential PDAC treatment.

Enhanced stiffness in peri-cancerous tissue: a marker of poor prognosis in papillary thyroid carcinoma with lymph node metastasis.

The prognostic significance of lymph node metastasis (LNM) in papillary thyroid carcinoma (PTC) remains controversial. Notably, there is evidence suggesting an association between tissue stiffness and the aggressiveness of the disease. We therefore aimed to explore the effect of tissue stiffness on LNM-related invasiveness in PTC patients. A total of 2492 PTC patients from 3 hospitals were divided into an LNM group and a non-LNM group based on their pathological results. The effects of interior lesion stiffness (E) and peri-cancerous tissue stiffness (Eshell) on the LNM-related recurrence rate and mortality in each patient with PTC subgroup were analyzed. The activation of cancer-associated fibroblasts (CAFs) and extracellular matrix component type 1 collagen (COL-I) in the lesion were compared and analyzed across different subgroups. The underlying biological basis of differences in each subgroup was identified using RNA sequencing (RNA-seq) data. The Eshell value and Eshell/E in the LNM group were significantly higher than those in the non-LNM group of patients with PTC (Eshell: 72.72 ± 5.63 vs 66.05 ± 4.46; Eshell/E: 1.20 ± 1.72 vs 1.09 ± 1.10, P < .001). When Eshell/E > 1.412 and LNM were both present, the recurrence rate and mortality were significantly increased compared to those of group of patients with LNM (91.67% and 7.29%, respectively). The CAF activation and COL-I content in the Eshell/E+ group were significantly higher than those in the Eshell/E- group (all P < .001), and the RNA-seq results revealed significant extracellular matrix (ECM) remodeling in the LNM-Eshell/E+ group. Stiff peri-cancerous tissue induced CAF activation, COL-I deposition, and ECM remodeling, resulting in a poor prognosis for PTC patients with LNM.

Asperuloside inhibits the activation of pancreatic cancer-associated fibroblasts via activating transcription factor 6

BackgroundPancreatic cancer-associated fibroblasts (CAFs) play a crucial role in tumor progression and immune evasion. Asperuloside (ASP) is an iridoid glycoside with potential anti-tumor properties. This study aimed to explore the molecular mechanisms of ASP on CAFs, particularly focusing on its effects on activating transcription factor 6 (ATF6), a key regulator of endoplasmic reticulum stress.MethodCAFs were treated with different concentrations of ASP (0, 1, 3, and 5 mM), and the role of ATF6 was investigated by over-expressing it in CAFs. Subsequently, western blot was used to detect ATF6, α-smooth muscle actin (α-SMA), fibroblast activating protein (FAP), and vimentin protein levels in CAFs. The collagen gel contraction assay and Transwell assay were applied to evaluate the contraction and migration ability of CAFs. In addition, the interleukin (IL)-6, C–C motif chemokine ligand (CCL)-2, and C-X-C motif chemokine ligand (CXCL)-10 levels were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR).ResultsCAFs had significantly higher expression levels of α-SMA, FAP, and vimentin compared to normal fibroblasts (NFs). ASP significantly inhibited the activation, contraction, and migration of CAFs in a concentration-dependent manner. ASP treatment also reduced the expression of cytokines (IL-6, CCL2, and CXCL10) and down-regulated ATF6 levels. Over-expression of ATF6 mitigated the inhibitory effects of ASP.ConclusionASP exerts its anti-tumor effects by down-regulating ATF6, thereby inhibiting the activation and function of pancreatic CAFs. These findings suggest that ASP could be a promising therapeutic agent for pancreatic cancer by modulating the tumor microenvironment.