Deconstruction of a Metastatic Tumor Microenvironment Reveals a Common Matrix Response in Human Cancers

Unveiling the role of extracellular matrix elements and regulators in shaping ovarian cancer growth and metastasis

Epithelial ovarian cancer (EOC) progression is determined by numerous intracellular interactions and the interplay between malignant cells, normal cells, and the tumor acellular microenvironment, formed largely by the extracellular matrix (ECM). The structure and biochemical functioning of various ECM components, along with the activity of agents that regulate ECM remodeling, impact the disease's expansion (adhesion, proliferation, invasion), spread, and response to therapy. It is important to note that the involvement of ECM components and their regulators in the progression of EOC is bidirectional and distinctly depends on a particular tissue context. In certain situations, certain components of the ECM enhance the activity of cancer cells, but in other scenarios, they suppress it. In this review, we summarize the newest knowledge regarding diverse aspects of ECM engagement in EOC pathophysiology and chemotherapy. Moreover, we delineate conditions that exacerbate the pro-cancerous properties of ECM, including diabetes-associated glycation, aging, and cellular senescence. We also explore methods to therapeutically alter the properties of the ECM, which could be beneficial in ovarian cancer prevention and treatment.

Identifying functional roles and pathways of shared mutations in canine solid tumors by whole-genome sequencing

Identifying genetic mutations contributing to solid tumors by altering the biological pathways related to tumor formation and development is essential for the development of targeted therapies. This study aimed to identify commonly mutated genes and altered pathways in canine solid tumors. Four dogs with different types of naturally occurring neoplasias (urothelial carcinoma, adenocarcinoma, rhabdomyosarcoma, and chondrosarcoma) were randomly selected and classified into carcinoma and sarcoma groups based on histopathological findings. Tumor tissues were analyzed using whole-genome sequencing, and significant variants shared within each tumor group were identified. Gene set enrichment analyses were conducted to compare the biological and functional pathways altered by the mutations in each carcinoma and sarcoma group. Forty-three and fifty-eight genes were identified in the carcinoma and sarcoma groups, respectively. Distinctions between the two tumor groups were noted for mutations related to tumor metastatic function. Mutations were identified in genes encoding cell adhesion molecules in the carcinoma group, whereas significant variations in extracellular matrix-related molecules were evident in the sarcoma group. This study revealed mutations and modified pathways associated with immune and tumor metastatic functions in canine carcinoma and sarcoma, indicating their significant relevance to the development and progression of each tumor group. Additionally, the distinctions indicated that different therapeutic approaches were required for each tumor group.

Interactions between cancer-associated fibroblasts and the extracellular matrix in oesophageal cancer

Stromal components of the tumour microenvironment, such as cancer-associated fibroblasts (CAFs) and the extracellular matrix (ECM), are actively involved in tumorigenesis. CAFs and the ECM co-evolve with resultant molecular and mechanical pressure on tumour cells mediated by CAFs via the ECM. Meanwhile, ECM fibers determine CAF differentiation and activity, establishing a protumorigenic feed-forward loop. Oesophageal cancer carries a high morbidity and mortality, and curative surgical resection is only an option for a limited number of patients while early lymphatic spread and poor therapeutic responses are common. Although studies report marked heterogeneity in investigation of the stromal density of gastrointestinal cancers, it is generally accepted that oesophageal cancer is highly fibrotic, and stromal components like CAFs may outnumber cancer cells. Therefore, a comprehensive understanding of the reciprocal interaction between CAFs and the ECM in oesophageal cancer is essential to improving diagnostics and prognostication, as well as designing innovative anti-cancer strategies. Here, we summarise current understanding of oesophageal cancer from a stromal perspective. Then, we discuss that CAFs and the ECM in oesophageal cancer can independently and synergistically contribute to tumour progression and therapeutic resistance. We also summarise potential stromal targets that have been described in transcriptomic analyses, highlighting those validated in downstream experimental studies. Importantly, clinical translation of stromal-targeting strategies in oesophageal cancer is still in its infancy but holds significant promise for future therapeutic combinations.

Role of tumor microenvironment in ovarian cancer metastasis and clinical advancements

Ovarian cancer (OC) is the most lethal gynecological malignancy worldwide, characterized by heterogeneity at the molecular, cellular and anatomical levels. Most patients are diagnosed at an advanced stage, characterized by widespread peritoneal metastasis. Despite optimal cytoreductive surgery and platinum-based chemotherapy, peritoneal spread and recurrence of OC are common, resulting in poor prognoses. The overall survival of patients with OC has not substantially improved over the past few decades, highlighting the urgent necessity of new treatment options. Unlike the classical lymphatic and hematogenous metastasis observed in other malignancies, OC primarily metastasizes through widespread peritoneal seeding. Tumor cells (the "seeds") exhibit specific affinities for certain organ microenvironments (the "soil"), and metastatic foci can only form when there is compatibility between the "seeds" and "soil." Recent studies have highlighted the tumor microenvironment (TME) as a critical factor influencing the interactions between the "seeds" and "soil," with ascites and the local peritoneal microenvironment playing pivotal roles in the initiation and progression of OC. Prior to metastasis, the interplay among tumor cells, immunosuppressive cells, and stromal cells leads to the formation of an immunosuppressive pre-metastatic niche in specific sites. This includes characteristic alterations in tumor cells, recruitment and functional anomalies of immune cells, and dysregulation of stromal cell distribution and function. TME-mediated crosstalk between cancer and stromal cells drives tumor progression, therapy resistance, and metastasis. In this review, we summarize the current knowledge on the onset and metastatic progression of OC. We provide a comprehensive discussion of the characteristics and functions of TME related to OC metastasis, as well as its association with peritoneal spread. We also outline ongoing relevant clinical trials, aiming to offer new insights for identifying potential effective biomarkers and therapeutic targets in future clinical practice.

Collagen fiber density observed in metastatic ovarian cancer promotes tumor cell adhesion

Collagen type I, a key structural component of the extracellular matrix (ECM), is frequently altered in cancer, with altered fiber organization at the primary tumor site linked to metastasis and poor patient outcomes. Here, we demonstrate that collagen fibers are also altered in metastatic sites such as the omentum of patients with high-grade serous ovarian cancer (HGSOC). Specifically, we observed a significant increase in fiber density, alignment, and width. To determine if the increase in fiber density supports metastasis, we used a semi-interpenetrating methacrylated gelatin (gelMA) network in combination with increasing fibrillar collagen. Cancer cells had significantly increased adhesion as collagen fiber density increased. To determine the responsible mechanisms, we used orthogonal systems to examine 1) the different adhesion peptides exposed in collagen (GFOGER) and gelatin (RGD), and 2) the physical structure of fibers. Cells had minimal response to GFOGER, either alone or in combination with RGD, suggesting that increased adhesion did not result from this collagen-specific interaction. Cell adhesion was significantly higher on electrospun PCL-gelatin fibers compared to flat PCL-gelatin substrates, suggesting that increased cell adhesion resulted from fiber structure. We next investigated the cellular mechanisms involved in increased adhesion on gelMA/coll and found that actin polymerization, but not myosin II contractility, was needed. We further demonstrated that cells on fibrous gels had more robust actin polymerization, and that this resulted in greater adhesion strength. Combined, these results suggest that the increase in collagen fibers with tumor metastasis will support the development of additional metastases. STATEMENT OF SIGNIFICANCE: This work advances the evaluation of the matrisome of the omentum, the most common metastatic site in advanced ovarian cancer by characterizing how collagen fibers change with disease progression. To examine the effect of collagen fibers on metastasis, we utilized a suite of in vitro biomaterials to identify a novel role for collagen fibers in supporting cell adhesion through increased actin dynamics during nascent adhesion formation, which results in increased adhesion strength at later times.

Halofuginone Disrupted Collagen Deposition via mTOR-eIF2α-ATF4 Axis to Enhance Chemosensitivity in Ovarian Cancer

The interplay between cancer-associated fibroblasts (CAFs) and extracellular matrix (ECM) mediates progress, metastasis, and therapy resistance. However, strategy of targeting ECM remodeling to enhance chemosensitivity in ovarian cancer remains elusive. Here, a 22-gene matrisome signature predicts chemotherapy response and survival in ovarian cancer. The dense, collagen-rich ECM secreted by CAFs harbors more M2 tumor-associated macrophages (TAMs) than the looser ECM based on single cell RNA-seq (scRNA-seq) of ovarian cancer, suggesting the promising approach of targeting collagen to remodel ECM. An integrated analysis identifies collagen type I alpha 1 chain (COL1A1) as a major component of the ECM that contributes to chemoresistance and poor prognosis, highlighting its potential as a therapeutic target. Halofuginone (HF), a clinically active derivative of febrifugine, is identified as a COL1A1-targeting natural compound by screening the Encyclopedia of Traditional Chinese Medicine (ETCM). Mechanistically, HF inhibits COL1A1 production via the mTOR-eIF2α-ATF4 axis in CAFs. Notably, HF disrupts collagen deposition and promotes CD8+ T cell infiltration, partially via M2-M1 macrophage polarization to enhance chemosensitivity. Overall, the findings suggest that HF combined with chemotherapy is a promising and effective treatment for ovarian cancer.

Targeting Extra Domain A of Fibronectin to Improve Noninvasive Detection of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) lags behind other breast cancer types in targeted therapeutic and diagnostic imaging agent development, largely due to high disease heterogeneity. Noninvasive imaging is essential for diagnosing and staging TNBC and predicting and measuring treatment response. This study targeted a conserved disease-specific extracellular matrix protein domain (the extra domain A of fibronectin [EDA-FN]), with a monoclonal antibody (F8) to overcome tumor cell marker heterogeneity and develop an imaging agent to detect multiple TNBC subtypes and improve diagnostic capacity. Methods: [89Zr]Zr-desferrioxamine [DFO]-F8 was synthesized and evaluated in vitro and in vivo for EDA-FN binding capacity to detect TNBC by PET/CT in several preclinical xenograft models. Results: [89Zr]Zr-DFO-F8 exhibited specific, blockable EDA-FN binding activity in vitro. In vivo experiments demonstrated high tumor uptake in preclinical TNBC xenograft models. [89Zr]Zr-DFO-F8 detected EDA-FN in subcutaneous and orthotopic TNBC xenografts and accumulated in aggressive disease concordantly with EDA-FN expression. Conclusion: EDA-FN imaging with [89Zr]Zr-DFO-F8 exhibits powerful tumor delineation in preclinical tumor delineation across TNBC molecular subtypes in vivo.

Matrix stiffening from collagen fibril density and alignment modulates YAP-mediated T-cell immune suppression

T-cells are essential components of the immune system, adapting their behavior in response to the mechanical environments they encounter within the body. In pathological conditions like cancer, the extracellular matrix (ECM) often becomes stiffer due to increased density and alignment of collagen fibrils, which can have a significant impact on T-cell function. In this study, we explored how these ECM properties-density and fibrillar alignment-affect T-cell behavior using three-dimensional (3D) collagen matrices that mimic these conditions. Our results show that increased matrix stiffness, whether due to higher density or alignment, significantly suppresses T-cell activation, reduces cytokine production, and limits proliferation, largely through enhanced YAP signaling. Individually, matrix alignment appears to lower actin levels in activated T-cells and changes migration behavior in both resting and activated T-cells, an effect not observed in matrices with randomly oriented fibrils. Notably, inhibiting YAP signaling was able to restore T-cell activation and improve immune responses, suggesting a potential strategy to boost the effectiveness of immunotherapy in stiff ECM environments. Overall, this study provides new insights into how ECM characteristics influence T-cell function, offering potential avenues for overcoming ECM-induced immunosuppression in diseases such as cancer.

The silent spread: exploring diverse metastatic pathways in high-grade serous ovarian cancer

High-grade serous ovarian cancer (HGSOC) is a highly aggressive and deadly gynecological cancer, with metastasis being a key factor in its poor prognosis. Historically, HGSOC was thought to spread primarily through the peritoneal cavity, but recent research has revealed additional routes of metastasis, including the blood and lymphatic systems. This review discusses the complex processes of HGSOC metastasis, focusing on peritoneal immune suppression, stromal reprogramming, and the role of circulating tumor cells in blood-based spread. We also explore the clinical significance of lymphatic metastasis, particularly its impact on patient outcomes. Gaining insight into molecular and genetic drivers, such as BRCA mutations and interactions within the immune microenvironment, is essential for developing targeted treatments. Future studies should aim to enhance experimental models, identify early detection markers, and investigate novel therapeutic approaches to effectively address HGSOC metastasis and improve patient survival.

PPIA enhances cell growth and metastasis through CD147 in oral cancer

Oral cancer is a malignant tumor, and the associated death rate has significantly increased over the past few decades. Secreted fractions are involved in various physiological processes, and their analysis has become a promising approach for discovering diagnostic and prognostic biomarkers for cancer detection and monitoring metastasis. Therefore, the discovery of potential prognostic, diagnostic, and therapeutic biomarkers for oral cancer metastasis is beneficial for developing effective strategies in oral cancer therapy. In this study, we used secretomic analysis to identify the secreted proteins involved in oral cancer. One of the identified proteins, peptidylprolyl isomerase A (PPIA), was selected for further investigation. We used RNA interference to investigate the effect of PPIA secretion on invasion and migration of OC3-I5 cells. Our results showed that reducing the expression and secretion of PPIA significantly decreased invasion and migration of OC3-I5 cells. Next, we used recombinant PPIA to investigate its direct effect on OC3 cell metastasis. The results revealed that proliferation, migration, and invasion of OC3 cells were significantly increased by treatment with the recombinant PPIA. Immunohistochemical analyses revealed higher PPIA expression in tumor tissues compared to normal tissues. Concisely, PPIA activated the ERK1/2 and p38 MAPK signaling pathways and enhanced cell proliferation and metastasis through CD147. In summary, PPIA may prove to be a novel target for oral cancer therapy as well as a prognostic marker.

Matrix mechano-sensing at the invasive front induces a cytoskeletal and transcriptional memory supporting metastasis

The extracellular matrix (ECM) controls tumour dissemination. We characterise ECM organization in human and mouse tumours, identifying three regions: tumour body, proximal invasive front and distal invasive front. Invasive areas show increased matrix density, fibre thickness, length, and alignment, with unique radial fibre orientation at the distal invasive front correlating with amoeboid invasive features. Using patient samples and murine models, we find that metastases recapitulate ECM features of the primary tumour. Ex vivo culture of murine cancer cells isolated from the different tumour regions reveals a spatial cytoskeletal and transcriptional memory. Several in vitro models recapitulate the in vivo ECM organisation showing that increased matrix induces 3D confinement supporting Rho-ROCK-Myosin II activity, while radial orientation enhances directional invasion. Spatial transcriptomics identifies a mechano-inflammatory program associated with worse prognosis across multiple tumour types. These findings provide mechanistic insights into how ECM organization shapes local invasion and distant metastasis.

Ovarian cancer-derived TGF-β1 induces cancer-associated adipocytes formation by activating SMAD3/TRIB3 pathway to establish pre-metastatic niche

Ovarian cancer (OC) is prone to adipose tissue metastasis. However, the underlying molecular mechanisms remain elusive. Here, we observed that omental adipocytes were induced into cancer-associated adipocytes (CAAs) by OC-derived TGF-β1 to establish a pre-metastatic niche (PMN) through collagen and fibronectin secretion. Mechanistically, OC-derived TGF-β1 binds to adipocyte membrane receptors and thus activates intracellular signaling by SMAD3 phosphorylation. The activation of TGF-β1/SMAD3 signaling pathway dedifferentiates adipocytes into CAAs by upregulating Tribbles homolog 3 (TRIB3), which suppresses the phosphorylation of CEBPβ. Additionally, CAAs secrete collagen I, collagen VI, and fibronectin to remodel the extracellular matrix and promote the adhesion of OC cells. Pharmacological inhibition of the TGF-β1/SMAD3 pathway significantly inhibits CAAs and PMN formation, thereby reducing the OC metastatic burden. Our findings indicate that the formation of CAAs and PMN in adipose tissues facilitates OC cell implantation and blocking the TGF-β1/SMAD3 signaling pathway could prevent OC omental metastasis.

Napabucasin-loaded PLGA nanoparticles trigger anti-HCC immune responses by metabolic reprogramming of tumor-associated macrophages

BACKGROUND

JAK/STAT3 is one of the critical signaling pathways involved in the occurrence and development of hepatocellular carcinoma (HCC). BBI608 (Napabucasin), as a novel small molecule inhibitor of STAT3, has shown previously excellent anti-HCC effects in vitro and in mouse models. However, low bioavailability, high cytotoxicity and other shortcomings limit its clinical application. In this study, PLGA was selected to prepare Napabucasin PLGA nanoparticles (NPs) by solvent evaporation method, overcoming these limitations and improving the passive targeting effect that nanoparticle mediated. Base on this, we systematically evaluated the anti-HCC effect of Napabucasin-PLGA NPs and explored the underlying mechanisms.

METHODS

Napabucasin-PLGA NPs were prepared by solvent evaporation method. CCK-8 assay, Annexin V/PI double staining, RT-qPCR, colony formation assay, and Western blotting were performed to evaluate the anti-HCC effect of Napabucasin-PLGA NPs in vitro. Proliferation assay and migration assay were used to detect the effects of Napabucasin-PLGA NPs-treated HCC-TAMs on tumor biological characteristics of HCC cells. Flow cytometry was used to detect anti-HCC immune responses induced by Napabucasin-PLGA NPs in vivo.

RESULTS

Our results demonstrated that Napabucasin-PLGA NPs could improve the bioavailability of Napabucasin and enhance Napabucasin-mediated the anti-HCC effects in vitro and in vivo with no significant drug toxicity. In addition to the direct inhibitory effects on the tumor biological characteristics of HCC cells, Napabucasin-PLGA NPs could promote the polarization of macrophages from tumor-promoting M2-type to anti-tumor M1-type, improving the tumor immune microenvironment and augmenting T cell-mediated anti-tumor responses. The underlining mechanisms showed Napabucasin-PLGA NPs suppressed the STAT3/FAO signaling axis in HCC-induced tumor-associated macrophages (TAMs).

CONCLUSIONS

These findings demonstrated Napabucasin-PLGA NPs is a potential therapeutic candidate for HCC, and provided a new theoretical and experimental basis for further development and clinical application of Napabucasin.

Crosstalk of T cells within the ovarian cancer microenvironment

Ovarian cancer (OC) represents ecosystems of highly diverse tumor microenvironments (TMEs). The presence of tumor-infiltrating lymphocytes (TILs) is linked to enhanced immune responses and long-term survival. In this review we present emerging evidence suggesting that cellular crosstalk tightly regulates the distribution of TILs within the TME, underscoring the need to better understand key cellular networks that promote or impede T cell infiltration in OC. We also capture the emergent methodologies and computational techniques that enable the dissection of cell-cell crosstalk. Finally, we present innovative ex vivo TME models that can be leveraged to map and perturb cellular communications to enhance T cell infiltration and immune reactivity.

Immunotherapy that improves response to chemotherapy in high-grade serous ovarian cancer

Single-cell RNA sequencing (scRNAseq) of tumour-infiltrating immune cells in high-grade serous ovarian cancer (HGSOC) omental biopsies reveals potential targets that could enhance response to neo-adjuvant chemotherapy (NACT). Analysis of 64,097 cells identifies NACT-induced overexpression of stabilin-1 (clever-1) on macrophages and FOXP3 in Tregs that is confirmed at the protein level. STAB1 inhibition in vitro induces anti-tumour macrophages. FOXP3 anti-sense oligonucleotide (FOXP3-ASO), repolarises Tregs to an effector T cell phenotype. ScRNAseq on 69,781 cells from an HGSOC syngeneic mouse model recapitulates the patients' data. Combining chemotherapy with anti-stabilin1 antibody and/or Foxp3-ASO significantly increases survival of mice with established peritoneal disease in two HGSOC syngeneic models and progression-free survival in a third model. Long-term survivors (300 days + ) are resistant to tumour rechallenge. Anti-stabilin1 antibody enriches the tumours with CXCL9+ macrophages and Foxp3-ASO increases TBET cell infiltration. Our results suggest that targeting these molecules in immune cells may improve chemotherapy response in patients.

PTEN Loss Shapes Macrophage Dynamics in High-Grade Serous Ovarian Carcinoma

High-grade serous ovarian carcinoma (HGSC) remains a disease with poor prognosis that is unresponsive to current immune checkpoint inhibitors. Although PI3K pathway alterations, such as PTEN loss, are common in HGSC, attempts to target this pathway have been unsuccessful. We hypothesized that aberrant PI3K pathway activation may alter the HGSC immune microenvironment and present a targeting opportunity. Single-cell RNA sequencing identified populations of resident macrophages specific to Pten-null omental tumors in murine models, which were confirmed by flow cytometry. These macrophages were derived from peritoneal fluid macrophages and exhibited a unique gene expression program, marked by high expression of the enzyme heme oxygenase-1 (HMOX1). Targeting resident peritoneal macrophages prevented the appearance of HMOX1hi macrophages and reduced tumor growth. In addition, direct inhibition of HMOX1 extended survival in vivo. RNA sequencing identified IL33 in Pten-null tumor cells as a likely candidate driver, leading to the appearance of HMOX1hi macrophages. Human HGSC tumors also contained HMOX1hi macrophages with a corresponding gene expression program. Moreover, the presence of these macrophages was correlated with activated tumoral PI3K/mTOR signaling and poor overall survival in patients with HGSC. In contrast, tumors with low numbers of HMOX1hi macrophages were marked by increased adaptive immune response gene expression. These data suggest targeting HMOX1hi macrophages as a potential therapeutic strategy for treating poor prognosis HGSC. Significance: Macrophages with elevated HMOX1 expression are enriched in PTEN-deficient high-grade serous ovarian carcinoma, promote tumor growth, and represent a potential therapeutic target.

Convergent evolution of senescent fibroblasts in fibrosis and cancer with aging

Aging is associated with stereotyped changes in the tissue microenvironment that increase susceptibility to diseases of the elderly, including organ fibrosis and cancer. From a tissue perspective, fibrosis and cancer can both be viewed as non-healing wounds with pathogenic activation of tissue repair pathways in the stroma. If fibrosis and cancer represent an example of the convergent evolution of maladaptive stromal responses in distinct pathologies, what are the analogous cell types that might emerge in both diseases that share similarities in identity and function? In this review, we explore how senescent fibroblasts form a nexus that connects the aging organ with both fibrosis and cancer. The advent of single cell sequencing, coupled with improved detection of cell types with senescent traits in vivo, have allowed us to identify senescent fibroblasts with similar identities in both fibrosis and cancer that share pro-fibrotic programs. In addition to their ability to reorganize the extracellular matrix in diseased states, these pro-fibrotic senescent fibroblasts can also promote epithelial reprogramming and immune rewiring, which drive disease progression in fibrosis and cancer. Finally, the identification of common pathogenic cell types in fibrosis and cancer also presents a therapeutic opportunity to target both diseases with a shared approach.

Matrisomics: Beyond the extracellular matrix for unveiling tumor microenvironment

The matrisome, a group of proteins constituting or interacting with the extracellular matrix (ECM), has garnered attention as a potent regulator of cancer progression. An increasing number of studies have focused on cancer matrisome utilizing diverse -omics approaches. Here, we present diverse patterns of matrisomal populations within cancer tissues, exploring recent -omics studies spanning different '-omics' levels (epigenomics, genomics, transcriptomics, and proteomics), as well as newly developed sequencing techniques such as single-cell RNA sequencing and spatial transcriptomics. Some matrisome genes showed uniform patterns of upregulated or downregulated expression across various cancers, while others displayed different expression patterns according to the cancer types. This matrisomal dysregulation in cancer was further examined according to their originating cell type and spatial location in the tumor tissue. Experimental studies were also collected to demonstrate the identified roles of matrisome genes during cancer progression. Interestingly, many studies on cancer matrisome have suggested matrisome genes as effective biomarkers in cancer research. Although the specific mechanisms and clinical applications of cancer matrisome have not yet been fully elucidated, recent techniques and analyses on cancer matrisomics have emphasized their biological importance in cancer progression and their clinical implications in deciding the efficacy of cancer treatment.

SLAMF7 predicts prognosis and correlates with immune infiltration in serous ovarian carcinoma

OBJECTIVE

Signaling lymphocytic activation molecule family members (SLAMFs) play a critical role in immune regulation of malignancies. This study aims to investigate the prognostic value and function of SLAMFs in ovarian cancer (OC).

METHODS

The expression analysis of SLAMFs was conducted based on The Cancer Genome Atlas Ovarian Cancer Collection (TCGA-OV) and Gene Expression Omnibus (GEO) databases. Immunohistochemistry (IHC) was further performed on tissue arrays (n=98) to determine the expression of SLAMF7. Kaplan-Meier plotter and multivariate Cox regression model were used to evaluate the correlation of SLAMF7 expression with survival outcomes of patients. The molecular function of SLAMF7 in OC was further investigated using Gene Set Enrichment Analysis (GSEA).

RESULTS

SLAMF7 mRNA expression were significantly upregulated in OC tumor tissue compared to normal tissue. IHC revealed that SLAMF7 expression was located in the interstitial parts of tumor tissue, and higher SLAMF7 expression was associated with favorable survival outcomes. GSEA demonstrated that SLAMF7 is involved immune-related pathways. Further analysis showed that SLAMF7 had a strong correlation with the T cell-specific biomarker (CD3) but not with the B cell (CD19, CD22, and CD23) and natural killer cell-specific biomarkers (CD85C, CD336, and CD337). Furthermore, IHC analysis confirmed that SLAMF7 was expressed in tumor-infiltrating T cells, and the IHC score of SLAMF7 was positively correlated with CD3 (r=0.85, p<0.001).

CONCLUSION

SLAMF7 is expressed in the interstitial components of clinical OC tissue, and higher SLAMF7 expression indicated a favorable prognosis for patients with OC. Additionally, SLAMF7 is involved in T-cell immune infiltration in OC.

Immune evasion: An imperative and consequence of MYC deregulation

MYC has been implicated in the pathogenesis of a wide range of human tumors and has been described for many years as a transcription factor that regulates genes with pleiotropic functions to promote tumorigenic growth. However, despite extensive efforts to identify specific target genes of MYC that alone could be responsible for promoting tumorigenesis, the field is yet to reach a consensus whether this is the crucial function of MYC. Recent work shifts the view on MYC's function from being a gene-specific transcription factor to an essential stress resilience factor. In highly proliferating cells, MYC preserves cell integrity by promoting DNA repair at core promoters, protecting stalled replication forks, and/or preventing transcription-replication conflicts. Furthermore, an increasing body of evidence demonstrates that MYC not only promotes tumorigenesis by driving cell-autonomous growth, but also enables tumors to evade the host's immune system. In this review, we summarize our current understanding of how MYC impairs antitumor immunity and why this function is evolutionarily hard-wired to the biology of the MYC protein family. We show why the cell-autonomous and immune evasive functions of MYC are mutually dependent and discuss ways to target MYC proteins in cancer therapy.

Comprehensive identification of a disulfidptosis-associated long non-coding RNA signature to predict the prognosis and treatment options in ovarian cancer

Purpose

Distinguished from cuproptosis and ferroptosis, disulfidptosis has been described as a newly discovered form of non-programmed cell death tightly associated with glucose metabolism. However, the prognostic profile of disulfidptosis-related lncRNAs (DRLRs) in ovarian cancer (OC) and their biological mechanisms need to be further elucidated.

Materials and methods

First, we downloaded the profiles of RNA transcriptome, clinical information for OC patients from the TCGA database. Generated from Cox regression analysis, prognostic lncRNAs were utilized to identify the risk signature by least absolute shrinkage and selection operator analysis. Then, we explored the intimate correlations between disulfidptosis and lncRNAs. What's more, we performed a series of systemic analyses to assess the robustness of the model and unravel its relationship with the immune microenvironment comprehensively.

Results

We identified two DRLR clusters, in which OC patients with low-risk scores exhibited a favorable prognosis, up-regulated immune cell infiltrations and enhanced sensitivity to immunotherapy. Furthermore, validation of the signature by clinical features and Cox analysis demonstrated remarkable consistency, suggesting the universal applicability of our model. It's worth noting that high-risk patients showed more positive responses to immune checkpoint inhibitors and potential chemotherapeutic drugs.

Conclusion

Our findings provided valuable insights into DRLRs in OC for the first time, which indicated an excellent clinical value in the selection of management strategies, spreading brilliant horizons into individualized therapy.

Tissue Mechanics and Hedgehog Signaling Crosstalk as a Key Epithelial-Stromal Interplay in Cancer Development

Epithelial-stromal interplay through chemomechanical cues from cells and matrix propels cancer progression. Elevated tissue stiffness in potentially malignant tissues suggests a link between matrix stiffness and enhanced tumor growth. In this study, employing chronic oral/esophageal injury and cancer models, it is demonstrated that epithelial-stromal interplay through matrix stiffness and Hedgehog (Hh) signaling is key in compounding cancer development. Epithelial cells actively interact with fibroblasts, exchanging mechanoresponsive signals during the precancerous stage. Specifically, epithelial cells release Sonic Hh, activating fibroblasts to produce matrix proteins and remodeling enzymes, resulting in tissue stiffening. Subsequently, basal epithelial cells adjacent to the stiffened tissue become proliferative and undergo epithelial-to-mesenchymal transition, acquiring migratory and invasive properties, thereby promoting invasive tumor growth. Notably, transcriptomic programs of oncogenic GLI2, mechano-activated by actin cytoskeletal tension, govern this process, elucidating the crucial role of non-canonical GLI2 activation in orchestrating the proliferation and mesenchymal transition of epithelial cells. Furthermore, pharmacological intervention targeting tissue stiffening proves highly effective in slowing cancer progression. These findings underscore the impact of epithelial-stromal interplay through chemo-mechanical (Hh-stiffness) signaling in cancer development, and suggest that targeting tissue stiffness holds promise as a strategy to disrupt chemo-mechanical feedback, enabling effective cancer treatment.

Inhibition of STAT3: A promising approach to enhancing the efficacy of chemotherapy in medulloblastoma

Medulloblastoma is a type of brain cancer that primarily affects children. While chemotherapy has been shown to be effective in treating medulloblastoma, the development of chemotherapy resistance remains a challenge. One potential therapeutic approach is to selectively inhibit the inducible transcription factor called STAT3, which is known to play a crucial role in the survival and growth of tumor cells. The activation of STAT3 has been linked to the growth and progression of various cancers, including medulloblastoma. Inhibition of STAT3 has been shown to sensitize medulloblastoma cells to chemotherapy, leading to improved treatment outcomes. Different approaches to STAT3 inhibition have been developed, including small-molecule inhibitors and RNA interference. Preclinical studies have shown the efficacy of STAT3 inhibitors in medulloblastoma, and clinical trials are currently ongoing to evaluate their safety and effectiveness in patients with various solid tumors, including medulloblastoma. In addition, researchers are also exploring ways to optimize the use of STAT3 inhibitors in combination with chemotherapy and identify biomarkers that can predict treatment that will help to develop personalized treatment strategies. This review highlights the potential of selective inhibition of STAT3 as a novel approach for the treatment of medulloblastoma and suggests that further research into the development of STAT3 inhibitors could lead to improved outcomes for patients with aggressive cancer.

Human 3D Ovarian Cancer Models Reveal Malignant Cell-Intrinsic and -Extrinsic Factors That Influence CAR T-cell Activity

In vitro preclinical testing of chimeric antigen receptor (CAR) T cells is mostly carried out in monolayer cell cultures. However, alternative strategies are needed to take into account the complexity and the effects of the tumor microenvironment. Here, we describe the modulation of CAR T-cell activity by malignant cells and fibroblasts in human three-dimensional (3D) in vitro cell models of increasing complexity. In models combining mucin-1 (MUC1) and TnMUC1 CAR T cells with human high-grade serous ovarian cancer cell spheroids, malignant cell-intrinsic resistance to CAR T-cell killing was due to defective death receptor signaling involving TNFα. Adding primary human fibroblasts to spheroids unexpectedly increased the ability of CAR T cells to kill resistant malignant cells as CCL2 produced by fibroblasts activated CCR2/4+ CAR T cells. However, culturing malignant cells and fibroblasts in collagen gels engendered production of a dense extracellular matrix that impeded CAR T-cell activity in a TGFβ-dependent manner. A vascularized microfluidic device was developed that allowed CAR T cells to flow through the vessels and penetrate the gels in a more physiological way, killing malignant cells in a TNFα-dependent manner. Complex 3D human cell models may provide an efficient way of screening multiple cytotoxic human immune cell constructs while also enabling evaluation of mechanisms of resistance involving cell-cell and cell-matrix interactions, thus accelerating preclinical research on cytotoxic immune cell therapies in solid tumors. Significance: Three-dimensional in vitro models of increasing complexity uncover mechanisms of resistance to CAR T cells in solid tumors, which could help accelerate development of improved CAR T-cell constructs.

Clinical Implications and Molecular Features of Extracellular Matrix Networks in Soft Tissue Sarcomas

PURPOSE

The landscape of extracellular matrix (ECM) alterations in soft tissue sarcomas (STS) remains poorly characterized. We aimed to investigate the tumor ECM and adhesion signaling networks present in STS and their clinical implications.

EXPERIMENTAL DESIGN

Proteomic and clinical data from 321 patients across 11 histological subtypes were analyzed to define ECM and integrin adhesion networks. Subgroup analysis was performed in leiomyosarcomas (LMS), dedifferentiated liposarcomas (DDLPS), and undifferentiated pleomorphic sarcomas (UPS).

RESULTS

This analysis defined subtype-specific ECM profiles including enrichment of basement membrane proteins in LMS and ECM proteases in UPS. Across the cohort, we identified three distinct coregulated ECM networks which are associated with tumor malignancy grade and histological subtype. Comparative analysis of LMS cell line and patient proteomic data identified the lymphocyte cytosolic protein 1 cytoskeletal protein as a prognostic factor in LMS. Characterization of ECM network events in DDLPS revealed three subtypes with distinct oncogenic signaling pathways and survival outcomes. Evaluation of the DDLPS subtype with the poorest prognosis nominates ECM remodeling proteins as candidate antistromal therapeutic targets. Finally, we define a proteoglycan signature that is an independent prognostic factor for overall survival in DDLPS and UPS.

CONCLUSIONS

STS comprise heterogeneous ECM signaling networks and matrix-specific features that have utility for risk stratification and therapy selection, which could in future guide precision medicine in these rare cancers.

The endothelin-1-driven tumor-stroma feed-forward loops in high-grade serous ovarian cancer

The high-grade serous ovarian cancer (HG-SOC) tumor microenvironment (TME) is constellated by cellular elements and a network of soluble constituents that contribute to tumor progression. In the multitude of the secreted molecules, the endothelin-1 (ET-1) has emerged to be implicated in the tumor/TME interplay; however, the molecular mechanisms induced by the ET-1-driven feed-forward loops (FFL) and associated with the HG-SOC metastatic potential need to be further investigated. The tracking of the patient-derived (PD) HG-SOC cell transcriptome by RNA-seq identified the vascular endothelial growth factor (VEGF) gene and its associated signature among those mostly up-regulated by ET-1 and down-modulated by the dual ET-1R antagonist macitentan. Within the ligand-receptor pairs concurrently expressed in PD-HG-SOC cells, endothelial cells and activated fibroblasts, we discovered two intertwined FFL, the ET-1/ET-1R and VEGF/VEGF receptors, concurrently activated by ET-1 and shutting-down by macitentan, or by the anti-VEGF antibody bevacizumab. In parallel, we observed that ET-1 fine-tuned the tumoral and stromal secretome toward a pro-invasive pattern. Into the fray of the HG-SOC/TME double and triple co-cultures, the secretion of ET-1 and VEGF, that share a common co-regulation, was inhibited upon the administration of macitentan. Functionally, macitentan, mimicking the effect of bevacizumab, interfered with the HG-SOC/TME FFL-driven communication that fuels the HG-SOC invasive behavior. The identification of ET-1 and VEGF FFL as tumor and TME actionable vulnerabilities, reveals how ET-1R blockade, targeting the HG-SOC cells and the TME simultaneously, may represent an effective therapeutic option for HG-SOC patients.

A Self-Assembled 3D Model Demonstrates How Stiffness Educates Tumor Cell Phenotypes and Therapy Resistance in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense and stiff extracellular matrix (ECM) associated with tumor progression and therapy resistance. To further the understanding of how stiffening of the tumor microenvironment (TME) contributes to aggressiveness, a three-dimensional (3D) self-assembling hydrogel disease model is developed based on peptide amphiphiles (PAs, PA-E3Y) designed to tailor stiffness. The model displays nanofibrous architectures reminiscent of native TME and enables the study of the invasive behavior of PDAC cells. Enhanced tuneability of stiffness is demonstrated by interacting thermally annealed aqueous solutions of PA-E3Y (PA-E3Yh) with divalent cations to create hydrogels with mechanical properties and ultrastructure similar to native tumor ECM. It is shown that stiffening of PA-E3Yh hydrogels to levels found in PDAC induces ECM deposition, promotes epithelial-to-mesenchymal transition (EMT), enriches CD133+/CXCR4+ cancer stem cells (CSCs), and subsequently enhances drug resistance. The findings reveal how a stiff 3D environment renders PDAC cells more aggressive and therefore more faithfully recapitulates in vivo tumors.

The importance of 3D fibre architecture in cancer and implications for biomaterial model design

The need for improved prediction of clinical response is driving the development of cancer models with enhanced physiological relevance. A new concept of 'precision biomaterials' is emerging, encompassing patient-mimetic biomaterial models that seek to accurately detect, treat and model cancer by faithfully recapitulating key microenvironmental characteristics. Despite recent advances allowing tissue-mimetic stiffness and molecular composition to be replicated in vitro, approaches for reproducing the 3D fibre architectures found in tumour extracellular matrix (ECM) remain relatively unexplored. Although the precise influences of patient-specific fibre architecture are unclear, we summarize the known roles of tumour fibre architecture, underlining their implications in cell-matrix interactions and ultimately clinical outcome. We then explore the challenges in reproducing tissue-specific 3D fibre architecture(s) in vitro, highlighting relevant biomaterial fabrication techniques and their benefits and limitations. Finally, we discuss imaging and image analysis techniques (focussing on collagen I-optimized approaches) that could hold the key to mapping tumour-specific ECM into high-fidelity biomaterial models. We anticipate that an interdisciplinary approach, combining materials science, cancer research and image analysis, will elucidate the role of 3D fibre architecture in tumour development, leading to the next generation of patient-mimetic models for mechanistic studies and drug discovery.

Recent advances in understanding the immune microenvironment in ovarian cancer

The occurrence of ovarian cancer (OC) is a major factor in women's mortality rates. Despite progress in medical treatments, like new drugs targeting homologous recombination deficiency, survival rates for OC patients are still not ideal. The tumor microenvironment (TME) includes cancer cells, fibroblasts linked to cancer (CAFs), immune-inflammatory cells, and the substances these cells secrete, along with non-cellular components in the extracellular matrix (ECM). First, the TME mainly plays a role in inhibiting tumor growth and protecting normal cell survival. As tumors progress, the TME gradually becomes a place to promote tumor cell progression. Immune cells in the TME have attracted much attention as targets for immunotherapy. Immune checkpoint inhibitor (ICI) therapy has the potential to regulate the TME, suppressing factors that facilitate tumor advancement, reactivating immune cells, managing tumor growth, and extending the survival of patients with advanced cancer. This review presents an outline of current studies on the distinct cellular elements within the OC TME, detailing their main functions and possible signaling pathways. Additionally, we examine immunotherapy rechallenge in OC, with a specific emphasis on the biological reasons behind resistance to ICIs.

Homologous recombination proficient subtypes of high-grade serous ovarian cancer: treatment options for a poor prognosis group

Approximately 50% of tubo-ovarian high-grade serous carcinomas (HGSCs) have functional homologous recombination-mediated (HR) DNA repair, so-called HR-proficient tumors, which are often associated with primary platinum resistance (relapse within six months after completion of first-line therapy), minimal benefit from poly(ADP-ribose) polymerase (PARP) inhibitors, and shorter survival. HR-proficient tumors comprise multiple molecular subtypes including cases with CCNE1 amplification, AKT2 amplification or CDK12 alteration, and are often characterized as "cold" tumors with fewer infiltrating lymphocytes and decreased expression of PD-1/PD-L1. Several new treatment approaches aim to manipulate these negative prognostic features and render HR-proficient tumors more susceptible to treatment. Alterations in multiple different molecules and pathways in the DNA damage response are driving new drug development to target HR-proficient cancer cells, such as inhibitors of the CDK or P13K/AKT pathways, as well as ATR inhibitors. Treatment combinations with chemotherapy or PARP inhibitors and agents targeting DNA replication stress have shown promising preclinical and clinical results. New approaches in immunotherapy are also being explored, including vaccines or antibody drug conjugates. Many approaches are still in the early stages of development and further clinical trials will determine their clinical relevance. There is a need to include HR-proficient tumors in ovarian cancer trials and to analyze them in a more targeted manner to provide further evidence for their specific therapy, as this will be crucial in improving the overall prognosis of HGSC and ovarian cancer in general.

Investigating gene signatures associated with immunity in colon adenocarcinoma to predict the immunotherapy effectiveness using NFM and WGCNA algorithms

Colon adenocarcinoma (COAD), a frequently encountered and highly lethal malignancy of the digestive system, has been the focus of intensive research regarding its prognosis. The intricate immune microenvironment plays a pivotal role in the pathological progression of COAD; nevertheless, the underlying molecular mechanisms remain incompletely understood. This study aims to explore the immune gene expression patterns in COAD, construct a robust prognostic model, and delve into the molecular mechanisms and potential therapeutic targets for COAD liver metastasis, thereby providing critical support for individualized treatment strategies and prognostic evaluation. Initially, we curated a comprehensive dataset by screening 2600 immune-related genes (IRGs) from the ImmPort and InnateDB databases, successfully obtaining a rich data resource. Subsequently, the COAD patient cohort was classified using the non-negative matrix factorization (NMF) algorithm, enabling accurate categorization. Continuing on, utilizing the weighted gene co-expression network analysis (WGCNA) method, we analyzed the top 5000 genes with the smallest p-values among the differentially expressed genes (DEGs) between immune subtypes. Through this rigorous screening process, we identified the gene modules with the strongest correlation to the COAD subpopulation, and the intersection of genes in these modules with DEGs (COAD vs COAD vs Normal colon tissue) is referred to as Differentially Expressed Immune Genes Associated with COAD (DEIGRC). Employing diverse bioinformatics methodologies, we successfully developed a prognostic model (DPM) consisting of six genes derived from the DEIGRC, which was further validated across multiple independent datasets. Not only does this predictive model accurately forecast the prognosis of COAD patients, but it also provides valuable insights for formulating personalized treatment regimens. Within the constructed DPM, we observed a downregulation of CALB2 expression levels in COAD tissues, whereas NOXA1, KDF1, LARS2, GSR, and TIMP1 exhibited upregulated expression levels. These genes likely play indispensable roles in the initiation and progression of COAD and thus represent potential therapeutic targets for patient management. Furthermore, our investigation into the molecular mechanisms and therapeutic targets for COAD liver metastasis revealed associations with relevant processes such as fat digestion and absorption, cancer gene protein polysaccharides, and nitrogen metabolism. Consequently, genes including CAV1, ANXA1, CPS1, EDNRA, and GC emerge as promising candidates as therapeutic targets for COAD liver metastasis, thereby providing crucial insights for future clinical practices and drug development. In summary, this study uncovers the immune gene expression patterns in COAD, establishes a robust prognostic model, and elucidates the molecular mechanisms and potential therapeutic targets for COAD liver metastasis, thereby possessing significant theoretical and clinical implications. These findings are anticipated to offer substantial support for both the treatment and prognosis management of COAD patients.

Targets in the Tumour Matrisome to Promote Cancer Therapy Response

The extracellular matrix (ECM) is composed of complex fibrillar proteins, proteoglycans, and macromolecules, generated by stromal, immune, and cancer cells. The components and organisation of the matrix evolves as tumours progress to invasive disease and metastasis. In many solid tumours, dense fibrotic ECM has been hypothesised to impede therapy response by limiting drug and immune cell access. Interventions to target individual components of the ECM, collectively termed the matrisome, have, however, revealed complex tumour-suppressor, tumour-promoter, and immune-modulatory functions, which have complicated clinical translation. The degree to which distinct components of the matrisome can dictate tumour phenotypes and response to therapy is the subject of intense study. A primary aim is to identify therapeutic opportunities within the matrisome, which might support a better response to existing therapies. Many matrix signatures have been developed which can predict prognosis, immune cell content, and immunotherapy responses. In this review, we will examine key components of the matrisome which have been associated with advanced tumours and therapy resistance. We have primarily focussed here on targeting matrisome components, rather than specific cell types, although several examples are described where cells of origin can dramatically affect tumour roles for matrix components. As we unravel the complex biochemical, biophysical, and intracellular transduction mechanisms associated with the ECM, numerous therapeutic opportunities will be identified to modify tumour progression and therapy response.

The role of Piezo1 mechanotransduction in high-grade serous ovarian cancer: Insights from an in vitro model of collective detachment

Slowing peritoneal spread in high-grade serous ovarian cancer (HGSOC) would improve patient prognosis and quality of life. HGSOC spreads when single cells and spheroids detach, float through the peritoneal fluid and take over new sites, with spheroids thought to be more aggressive than single cells. Using our in vitro model of spheroid collective detachment, we determine that increased substrate stiffness led to the detachment of more spheroids. We identified a mechanism where Piezo1 activity increased MMP-1/MMP-10, decreased collagen I and fibronectin, and increased spheroid detachment. Piezo1 expression was confirmed in omental masses from patients with stage III/IV HGSOC. Using OV90 and CRISPR-modified PIEZO1-/- OV90 in a mouse xenograft model, we determined that while both genotypes efficiently took over the omentum, loss of Piezo1 significantly decreased ascitic volume, tumor spheroids in the ascites, and the number of macroscopic tumors in the mesentery. These results support that slowing collective detachment may benefit patients and identify Piezo1 as a potential therapeutic target.

Omental preadipocytes stimulate matrix remodeling and IGF signaling to support ovarian cancer metastasis

Ovarian cancer can metastasize to the omentum, which is associated with a complex tumor microenvironment. Omental stromal cells facilitate ovarian cancer colonization by secreting cytokines and growth factors. Improved understanding of the tumor supportive functions of specific cell populations in the omentum could identify strategies to prevent and treat ovarian cancer metastasis. Here, we showed that omental preadipocytes enhance the tumor initiation capacity of ovarian cancer cells. Secreted factors from preadipocytes supported cancer cell viability during nutrient and isolation stress and enabled prolonged proliferation. Co-culturing with pre-adipocytes led to upregulation of genes involved in extracellular matrix (ECM) organization, cellular response to stress, and regulation of insulin-like growth factor (IGF) signaling in ovarian cancer cells. IGF-1 induced ECM genes and increased alternative NF-κB signaling by activating RelB. Inhibiting the IGF-1 receptor (IGF1R) initially increased tumor omental adhesion but decreased growth of established preadipocyte-induced subcutaneous tumors as well as established intraperitoneal tumors. Together, this study shows that omental preadipocytes support ovarian cancer progression, which has implications for targeting metastasis.

Versican Associates with Tumor Immune Phenotype and Limits T-cell Trafficking via Chondroitin Sulfate

Immunotherapies for cancers of epithelial origin have limited efficacy, and a growing body of evidence links the composition of extracellular matrix (ECM) with the likelihood of a favorable response to treatment. The ECM may be considered an immunologic barrier, restricting the localization of cytotoxic immune cells to stromal areas and inhibiting their contact with tumor cells. Identifying ECM components of this immunologic barrier could provide targets that whether degraded in situ may support antitumor immunity and improve immunotherapy response. Using a library of primary triple-negative breast cancer tissues, we correlated CD8+ T-cell tumor contact with ECM composition and identified a proteoglycan, versican (VCAN), as a putative member of the immunologic barrier. Our analysis reveals that CD8+ T-cell contact with tumor associates with the location of VCAN expression, the specific glycovariant of VCAN [defined through the pattern of posttranslational attachments of glycosaminoglycans (GAG)], and the cell types that produce the variant. In functional studies, the isomers of chondroitin sulfate presented on VCAN have opposing roles being either supportive or inhibiting of T-cell trafficking, and removal of the GAGs ameliorates these effects on T-cell trafficking. Overall, we conclude that VCAN can either support or inhibit T-cell trafficking within the tumor microenvironment depending on the pattern of GAGs present, and that VCAN is a major component of the ECM immunologic barrier that defines the type of response to immunotherapy.

SIGNIFICANCE

The response to immunotherapy has been poor toward solid tumors despite immune cells infiltrating into the tumor. The ECM has been associated with impacting T-cell infiltration toward the tumor and in this article we have identified VCAN and its structural modification, chondroitin sulfate as having a key role in T-cell invasion.

Comprehensive Matrisome Profiling of Human Adipose Tissue for Soft Tissue Reconstruction

For effective translation of research from tissue engineering and regenerative medicine domains, the cell-instructive extracellular matrix (ECM) of specific tissues must be accurately realized. As adipose tissue is gaining traction as a biomaterial for soft tissue reconstruction, with highly variable clinical outcomes obtained, a quantitative investigation of the adipose tissue matrisome is overdue. In this study, the human adipose tissue matrisome is profiled using quantitative sequential windowed acquisition of all theoretical fragment ion spectra - mass spectrometry (SWATH-MS) proteomics across a cohort of 13 fat-grafting patients, to provide characterization of ECM proteins within the tissue, and to understand human population variation. There are considerable differences in the expression of matrisome proteins across the patient cohort, with age and lipoaspirate collection technique contributing to the greatest variation across the core matrisome. A high abundance of basement membrane proteins (collagen IV and heparan sulfate proteoglycan) is detected, as well as fibrillar collagens I and II, reflecting the hierarchical structure of the tissue. This study provides a comprehensive proteomic evaluation of the adipose tissue matrisome and contributes to an enhanced understanding of the influence of the matrisome in adipose-related pathologies by providing a healthy reference cohort and details an experimental pipeline that can be further exploited for future biomaterial development.

The importance of cancer-associated fibroblasts in targeted therapies and drug resistance in breast cancer

Cancer-associated fibroblasts (CAFs) play a substantial role in the tumor microenvironment, exhibiting a strong association with the advancement of various types of cancer, including breast, pancreatic, and prostate cancer. CAFs represent the most abundant mesenchymal cell population in breast cancer. Through diverse mechanisms, including the release of cytokines and exosomes, CAFs contribute to the progression of breast cancer by influencing tumor energy metabolism, promoting angiogenesis, impairing immune cell function, and remodeling the extracellular matrix. Moreover, CAFs considerably impact the response to treatment in breast cancer. Consequently, the development of interventions targeting CAFs has emerged as a promising therapeutic approach in the management of breast cancer. This article provides an analysis of the role of CAFs in breast cancer, specifically in relation to diagnosis, treatment, drug resistance, and prognosis. The paper succinctly outlines the diverse mechanisms through which CAFs contribute to the malignant behavior of breast cancer cells, including proliferation, invasion, metastasis, and drug resistance. Furthermore, the article emphasizes the potential of CAFs as valuable tools for early diagnosis, targeted therapy, treatment resistance, and prognosis assessment in breast cancer, thereby offering novel approaches for targeted therapy and overcoming treatment resistance in this disease.

Breaking the stromal barrier in pancreatic cancer: Advances and challenges

Pancreatic cancer (PC) remains a leading cause of mortality worldwide due to the absence of early detection methods and the low success rates of traditional therapeutic strategies. Drug resistance in PC is driven by its desmoplastic stroma, which creates a barrier that shields cancer niches and prevents the penetration of drugs. The PC stroma comprises heterogeneous cellular populations and non-cellular components involved in aberrant ECM deposition, immunosuppression, and drug resistance. These components can influence PC development through intricate and complex crosstalk with the PC cells. Understanding how stromal components and cells interact with and influence the invasiveness and refractoriness of PC cells is thus a prerequisite for developing successful stroma-modulating strategies capable of remodeling the PC stroma to alleviate drug resistance and enhance therapeutic outcomes. In this review, we explore how non-cellular and cellular stromal components, including cancer-associated fibroblasts and tumor-associated macrophages, contribute to the immunosuppressive and tumor-promoting effects of the stroma. We also examine the signaling pathways underlying their activation, tumorigenic effects, and interactions with PC cells. Finally, we discuss recent pre-clinical and clinical work aimed at developing and testing novel stroma-modulating agents to alleviate drug resistance and improve therapeutic outcomes in PC.

Opposing roles for ADAMTS2 and ADAMTS14 in myofibroblast differentiation and function

Crosstalk between cancer and stellate cells is pivotal in pancreatic cancer, resulting in differentiation of stellate cells into myofibroblasts that drives tumour progression. To assess cooperative mechanisms in a 3D context, we generated chimeric spheroids using human and mouse cancer and stellate cells. Species-specific deconvolution of bulk-RNA sequencing data revealed cell type-specific transcriptomes underpinning invasion. This dataset highlighted stellate-specific expression of transcripts encoding the collagen-processing enzymes ADAMTS2 and ADAMTS14. Strikingly, loss of ADAMTS2 reduced, while loss of ADAMTS14 promoted, myofibroblast differentiation and invasion independently of their primary role in collagen-processing. Functional and proteomic analysis demonstrated that these two enzymes regulate myofibroblast differentiation through opposing roles in the regulation of transforming growth factor β availability, acting on the protease-specific substrates, Serpin E2 and fibulin 2, for ADAMTS2 and ADAMTS14, respectively. Showcasing a broader complexity for these enzymes, we uncovered a novel regulatory axis governing malignant behaviour of the pancreatic cancer stroma. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Stiffness-induced cancer-associated fibroblasts are responsible for immunosuppression in a platelet-derived growth factor ligand-dependent manner

Pancreatic ductal adenocarcinoma (PDAC) is associated with a vast stromal reaction that arises mainly from cancer-associated fibroblasts (CAFs) and promotes both immune escape and tumor growth. Here, we used a mouse model with deletion of the activin A receptor ALK4 in the context of the KrasG12D mutation, which strongly drives collagen deposition that leads to tissue stiffness. By ligand-receptor analysis of single-cell RNA-sequencing data, we identified that, in stiff conditions, neoplastic ductal cells instructed CAFs through sustained platelet-derived growth factor (PDGF) signaling. Tumor-associated tissue rigidity resulted in the emergence of stiffness-induced CAFs (siCAFs) in vitro and in vivo. Similar results were confirmed in human data. siCAFs were able to strongly inhibit CD8+ T-cell responses in vitro and in vivo, promoting local immunosuppression. More importantly, targeting PDGF signaling led to diminished siCAF and reduced tumor growth. Our data show for the first time that early paracrine signaling leads to profound changes in tissue mechanics, impacting immune responses and tumor progression. Our study highlights that PDGF ligand neutralization can normalize the tissue architecture independent of the genetic background, indicating that finely tuned stromal therapy may open new therapeutic avenues in pancreatic cancer.

Omentum-derived matrix enables the study of metastatic ovarian cancer and stromal cell functions in a physiologically relevant environment

High-grade serous (HGS) ovarian cancer is the most lethal gynaecological disease in the world and metastases is a major cause. The omentum is the preferential metastatic site in HGS ovarian cancer patients and in vitro models that recapitulate the original environment of this organ at cellular and molecular level are being developed to study basic mechanisms that underpin this disease. The tumour extracellular matrix (ECM) plays active roles in HGS ovarian cancer pathology and response to therapy. However, most of the current in vitro models use matrices of animal origin and that do not recapitulate the complexity of the tumour ECM in patients. Here, we have developed omentum gel (OmGel), a matrix made from tumour-associated omental tissue of HGS ovarian cancer patients that has unprecedented similarity to the ECM of HGS omental tumours and is simple to prepare. When used in 2D and 3D in vitro assays to assess cancer cell functions relevant to metastatic ovarian cancer, OmGel performs as well as or better than the widely use Matrigel and does not induce additional phenotypic changes to ovarian cancer cells. Surprisingly, OmGel promotes pronounced morphological changes in cancer associated fibroblasts (CAFs). These changes were associated with the upregulation of proteins that define subsets of CAFs in tumour patient samples, highlighting the importance of using clinically and physiologically relevant matrices for in vitro studies. Hence, OmGel provides a step forward to study the biology of HGS omental metastasis. Metastasis in the omentum are also typical of other cancer types, particularly gastric cancer, implying the relevance of OmGel to study the biology of other highly lethal cancers.

Proteomic analysis of exosomes secreted during the epithelial-mesenchymal transition and potential biomarkers of mesenchymal high-grade serous ovarian carcinoma

BACKGROUND

The epithelial-mesenchymal transition (EMT) promotes cell signaling and morphology alterations, contributing to cancer progression. Exosomes, extracellular vesicles containing proteins involved in cell-cell communication, have emerged as a potential source of biomarkers for several diseases.

METHODS

Our aim was to assess the proteome content of exosomes secreted after EMT-induction to identify potential biomarkers for ovarian cancer classification. EMT was induced in the ovarian cancer cell line CAOV3 by treating it with EGF (10 ng/mL) for 96 h following 24 h of serum deprivation. Subsequently, exosomes were isolated from the supernatant using selective centrifugation after decellularization, and their characteristics were determined. The proteins present in the exosomes were extracted, identified, and quantified using Label-Free-Quantification (LFQ) via Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). To identify potential biomarkers, the obtained proteomic data was integrated with the TGGA database for mRNA expression using principal component analysis and a conditional inference tree.

RESULTS

The exosomes derived from CAOV3 cells exhibited similar diameter and morphology, measuring approximately 150 nm, regardless of whether they were subjected to EMT stimulation or not. The proteomic analysis of proteins from CAOV3-derived exosomes revealed significant differential regulation of 157 proteins, with 100 showing upregulation and 57 downregulation upon EMT induction. Further comparison of the upregulated proteins with the TCGA transcriptomic data identified PLAU, LAMB1, COL6A1, and TGFB1 as potential biomarkers of the mesenchymal HGSOC subtype.

CONCLUSIONS

The induction of EMT, the isolation of exosomes, and the subsequent proteomic analysis highlight potential biomarkers for an aggressive ovarian cancer subtype. Further investigation into the role of these proteins is warranted to enhance our understanding of ovarian cancer outcomes.

Revisiting the Use of Normal Saline for Peritoneal Washing in Ovarian Cancer

The omentum is the predominant site of ovarian cancer metastasis, but it is difficult to remove the omentum in its entirety. There is a critical need for effective approaches that minimize the risk of colonization of preserved omental tissues by occult cancer cells. Normal saline (0.9% sodium chloride) is commonly used to wash the peritoneal cavity during ovarian cancer surgery. The omentum has a prodigious ability to absorb fluid in the peritoneal cavity, but the impact of normal saline on the omentum is poorly understood. In this review article, we discuss why normal saline is not a biocompatible solution, drawing insights from clinical investigations of normal saline in fluid resuscitation and from the cytopathologic evaluation of peritoneal washings. We integrate these insights with the unique biology of the omentum and omental metastasis, highlighting the importance of considering the absorptive ability of the omentum when administering agents into the peritoneal cavity. Furthermore, we describe insights from preclinical studies regarding the mechanisms by which normal saline might render the omentum conducive for colonization by cancer cells. Importantly, we discuss the possibility that the risk of colonization of preserved omental tissues might be minimized by using balanced crystalloid solutions for peritoneal washing.

Polyurethane scaffold-based 3D lung cancer model recapitulates in vivo tumor biological behavior for nanoparticulate drug screening

Lung cancer is the leading cause of cancer mortality worldwide. Preclinical studies in lung cancer hold the promise of screening for effective antitumor agents, but mechanistic studies and drug discovery based on 2D cell models have a high failure rate in getting to the clinic. Thus, there is an urgent need to explore more reliable and effective in vitro lung cancer models. Here, we prepared a series of three-dimensional (3D) waterborne biodegradable polyurethane (WBPU) scaffolds as substrates to establish biomimetic tumor models in vitro. These 3D WBPU scaffolds were porous and could absorb large amounts of free water, facilitating the exchange of substances (nutrients and metabolic waste) and cell growth. The scaffolds at wet state could simulate the mechanics (elastic modulus ∼1.9 kPa) and morphology (porous structures) of lung tissue and exhibit good biocompatibility. A549 lung cancer cells showed adherent growth pattern and rapidly formed 3D spheroids on WBPU scaffolds. Our results showed that the scaffold-based 3D lung cancer model promoted the expression of anti-apoptotic and epithelial-mesenchymal transition-related genes, giving it a more moderate growth and adhesion pattern compared to 2D cells. In addition, WBPU scaffold-established 3D lung cancer model revealed a closer expression of proteins to in vivo tumor, including tumor stem cell markers, cell proliferation, apoptosis, invasion and tumor resistance proteins. Based on these features, we further demonstrated that the 3D lung cancer model established by the WBPU scaffold was very similar to the in vivo tumor in terms of both resistance and tolerance to nanoparticulate drugs. Taken together, WBPU scaffold-based lung cancer model could better mimic the growth, microenvironment and drug response of tumor in vivo. This emerging 3D culture system holds promise to shorten the formulation cycle of individualized treatments and reduce the use of animals while providing valid research data for clinical trials.

Cancer Stem Cells and the Tumor Microenvironment in Tumor Drug Resistance

Although there has been some progress in the efficacy of anti-cancer drugs, drug resistance remains challenging. Cancer stem cells (CSCs) are self-renewing and differentiate into cancer tissues with tumor heterogeneity. CSCs are associated with the progression of breast, colon, and lung cancers. Hence, recent studies have focused on the role of CSCs in resistance to anti-cancer drugs. Increasing evidence suggests that CSCs interact with components of the tumor microenvironment (TME), such as vascular and immune cells, as well as various cytokines, and are regulated by multiple signaling pathways, thereby promoting drug resistance in various cancers. Therefore, it is important to clarify the mechanisms underlying the crosstalk between CSCs and the TME for the development of targeted anti-cancer therapies.

Toll-like receptor-guided therapeutic intervention of human cancers: molecular and immunological perspectives

Toll-like receptors (TLRs) serve as the body's first line of defense, recognizing both pathogen-expressed molecules and host-derived molecules released from damaged or dying cells. The wide distribution of different cell types, ranging from epithelial to immune cells, highlights the crucial roles of TLRs in linking innate and adaptive immunity. Upon stimulation, TLRs binding mediates the expression of several adapter proteins and downstream kinases, that lead to the induction of several other signaling molecules such as key pro-inflammatory mediators. Indeed, extraordinary progress in immunobiological research has suggested that TLRs could represent promising targets for the therapeutic intervention of inflammation-associated diseases, autoimmune diseases, microbial infections as well as human cancers. So far, for the prevention and possible treatment of inflammatory diseases, various TLR antagonists/inhibitors have shown to be efficacious at several stages from pre-clinical evaluation to clinical trials. Therefore, the fascinating role of TLRs in modulating the human immune responses at innate as well as adaptive levels directed the scientists to opt for these immune sensor proteins as suitable targets for developing chemotherapeutics and immunotherapeutics against cancer. Hitherto, several TLR-targeting small molecules (e.g., Pam3CSK4, Poly (I:C), Poly (A:U)), chemical compounds, phytocompounds (e.g., Curcumin), peptides, and antibodies have been found to confer protection against several types of cancers. However, administration of inappropriate doses of such TLR-modulating therapeutics or a wrong infusion administration is reported to induce detrimental outcomes. This review summarizes the current findings on the molecular and structural biology of TLRs and gives an overview of the potency and promises of TLR-directed therapeutic strategies against cancers by discussing the findings from established and pipeline discoveries.

Transcriptome profiling of patient-derived tumor xenografts suggests novel extracellular matrix-related signatures for gastric cancer prognosis prediction

BACKGROUND

A major obstacle to the development of personalized therapies for gastric cancer (GC) is the prevalent heterogeneity at the intra-tumor, intra-patient, and inter-patient levels. Although the pathological stage and histological subtype diagnosis can approximately predict prognosis, GC heterogeneity is rarely considered. The extracellular matrix (ECM), a major component of the tumor microenvironment (TME), extensively interacts with tumor and immune cells, providing a possible proxy to investigate GC heterogeneity. However, ECM consists of numerous protein components, and there are no suitable models to screen ECM-related genes contributing to tumor growth and prognosis. We constructed patient-derived tumor xenograft (PDTX) models to obtain robust ECM-related transcriptomic signatures to improve GC prognosis prediction and therapy design.

METHODS

One hundred twenty two primary GC tumor tissues were collected to construct PDTX models. The tumorigenesis rate and its relationship with GC prognosis were investigated. Transcriptome profiling was performed for PDTX-originating tumors, and least absolute shrinkage and selection operator (LASSO) Cox regression analysis was applied to extract prognostic ECM signatures and establish PDTX tumorigenicity-related gene (PTG) scores. The predictive ability of the PTG score was validated using two independent cohorts. Finally, we combined PTG score, age, and pathological stage information to establish a robust nomogram for GC prognosis prediction.

RESULTS

We found that PDTX tumorigenicity indicated a poor prognosis in patients with GC, even at the same pathological stage. Transcriptome profiling of PDTX-originating GC tissues and corresponding normal controls identified 383 differentially expressed genes, with enrichment of ECM-related genes. A robust prognosis prediction model using the PTG score showed robust performance in two validation cohorts. A high PTG score was associated with elevated M2 polarized macrophage and cancer-associated fibroblast infiltration. Finally, combining the PTG score with age and TNM stage resulted in a more effective prognostic model than age or TNM stage alone.

CONCLUSIONS

We found that ECM-related signatures may contribute to PDTX tumorigenesis and indicate a poor prognosis in GC. A feasible survival prediction model was built based on the PTG score, which was associated with immune cell infiltration. Together with patient ages and pathological TNM stages, PTG score could be a new approach for GC prognosis prediction.

Insights into the tumor-stromal-immune cell metabolism cross talk in ovarian cancer

The ovarian cancer tumor microenvironment (TME) consists of a constellation of abundant cellular components, extracellular matrix, and soluble factors. Soluble factors, such as cytokines, chemokines, structural proteins, extracellular vesicles, and metabolites, are critical means of noncontact cellular communication acting as messengers to convey pro- or antitumorigenic signals. Vast advancements have been made in our understanding of how cancer cells adapt their metabolism to meet environmental demands and utilize these adaptations to promote survival, metastasis, and therapeutic resistance. The stromal TME contribution to this metabolic rewiring has been relatively underexplored, particularly in ovarian cancer. Thus, metabolic activity alterations in the TME hold promise for further study and potential therapeutic exploitation. In this review, we focus on the cellular components of the TME with emphasis on 1) metabolic signatures of ovarian cancer; 2) understanding the stromal cell network and their metabolic cross talk with tumor cells; and 3) how stromal and tumor cell metabolites alter intratumoral immune cell metabolism and function. Together, these elements provide insight into the metabolic influence of the TME and emphasize the importance of understanding how metabolic performance drives cancer progression.

Preexisting Immunity Drives the Response to Neoadjuvant Chemotherapy in Esophageal Adenocarcinoma

Current treatment for patients with locally advanced esophageal adenocarcinoma (EAC) is neoadjuvant chemotherapy (nCT), alone or combined with radiotherapy, before surgery. However, fewer than 30% of treated patients show a pathologic complete response to nCT, which correlates with increased 5-year survival compared with nonresponders. Understanding the mechanisms of response to nCT is pivotal to better stratify patients and inform more efficacious therapies. Here, we investigated the immune mechanisms involved in nCT response by multidimensional profiling of pretreatment tumor biopsies and blood from 68 patients with EAC (34 prospectively and 34 retrospectively collected), comparing complete responders versus nonresponders to nCT. At the tumor level, complete response to nCT was associated with molecular signatures of immune response and proliferation, increased putative antitumor tissue-resident memory CD39+ CD103+ CD8+ T cells, and reduced immunosuppressive T regulatory cells (Treg) and M2-like macrophages. Systemically, complete responders showed higher frequencies of immunostimulatory CD14+ CD11c+ HLA-DRhigh cells, and reduced programmed cell death ligand 1-positive (PD-L1+) monocytic myeloid-derived suppressor cells, along with high plasma GM-CSF (proinflammatory) and low IL4, CXCL10, C3a, and C5a (suppressive). Plasma proinflammatory and suppressive cytokines correlated directly and inversely, respectively, with the frequency of tumor-infiltrating CD39+ CD103+ CD8+ T cells. These results suggest that preexisting immunity in baseline tumor drives the clinical activity of nCT in locally advanced EAC. Furthermore, it may be possible to stratify patients based on predictive immune signatures, enabling tailored neoadjuvant and/or adjuvant regimens.

SIGNIFICANCE

Multidimensional profiling of pretreatment esophageal adenocarcinoma shows patient response to nCT is correlated with active preexisting immunity and indicates molecular pathways of resistance that may be targeted to improve clinical outcomes.

Exploring the tumor immune microenvironment in ovarian cancer: a way-out to the therapeutic roadmap

INTRODUCTION

Despite cancer treatment strides, mortality due to ovarian cancer remains high globally. While immunotherapy has proven effective in treating cancers with low cure rates, it has limitations. Growing evidence suggests that both tumoral and non-tumoral components of the tumor immune microenvironment (TIME) play a significant role in cancer growth. Therefore, developing novel and focused therapy for ovarian cancer is critical. Studies indicate that TIME is involved in developing ovarian cancer, particularly genome-, transcriptome-, and proteome-wide studies. As a result, TIME may present a prospective therapeutic target for ovarian cancer patients.

AREAS COVERED

We examined several TIME-targeting medicines and the connection between TIME and ovarian cancer. The key protagonists and events in the TIME and therapeutic strategies that explicitly target these events in ovarian cancer are discussed.

EXPERT OPINION

We highlighted various targeted therapies against TIME in ovarian cancer, including anti-angiogenesis therapies and immune checkpoint inhibitors. While these therapies are in their infancy, they have shown promise in controlling ovarian cancer progression. The use of 'omics' technology is helping in better understanding of TIME in ovarian cancer and potentially identifying new therapeutic targets. TIME-targeted strategies could account for an additional treatment strategy when treating ovarian cancer.