Fibroblast heterogeneity and its impact on extracellular matrix and immune landscape remodeling in cancer

Tumor microenvironment and immunotherapy for triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer known for its high aggressiveness and poor prognosis. Conventional treatment of TNBC is challenging due to its heterogeneity and lack of clear targets. Recent advancements in immunotherapy have shown promise in treating TNBC, with immune checkpoint therapy playing a significant role in comprehensive treatment plans. The tumor microenvironment (TME), comprising immune cells, stromal cells, and various cytokines, plays a crucial role in TNBC progression and response to immunotherapy. The high presence of tumor-infiltrating lymphocytes and immune checkpoint proteins in TNBC indicates the potential of immunotherapeutic strategies. However, the complexity of the TME, while offering therapeutic targets, requires further exploration of its multiple roles in immunotherapy. In this review, we discuss the interaction mechanism between TME and TNBC immunotherapy based on the characteristics and composition of TME, and elaborate on and analyze the effect of TME on immunotherapy, the potential of TME as an immune target, and the ability of TME as a biomarker. Understanding these dynamics will offer new insights for enhancing therapeutic approaches and investigating stratification and prognostic markers for TNBC patients.

Cold and hot tumors: from molecular mechanisms to targeted therapy

Immunotherapy has made significant strides in cancer treatment, particularly through immune checkpoint blockade (ICB), which has shown notable clinical benefits across various tumor types. Despite the transformative impact of ICB treatment in cancer therapy, only a minority of patients exhibit a positive response to it. In patients with solid tumors, those who respond well to ICB treatment typically demonstrate an active immune profile referred to as the "hot" (immune-inflamed) phenotype. On the other hand, non-responsive patients may exhibit a distinct "cold" (immune-desert) phenotype, differing from the features of "hot" tumors. Additionally, there is a more nuanced "excluded" immune phenotype, positioned between the "cold" and "hot" categories, known as the immune "excluded" type. Effective differentiation between "cold" and "hot" tumors, and understanding tumor intrinsic factors, immune characteristics, TME, and external factors are critical for predicting tumor response and treatment results. It is widely accepted that ICB therapy exerts a more profound effect on "hot" tumors, with limited efficacy against "cold" or "altered" tumors, necessitating combinations with other therapeutic modalities to enhance immune cell infiltration into tumor tissue and convert "cold" or "altered" tumors into "hot" ones. Therefore, aligning with the traits of "cold" and "hot" tumors, this review systematically delineates the respective immune characteristics, influencing factors, and extensively discusses varied treatment approaches and drug targets based on "cold" and "hot" tumors to assess clinical efficacy.

Establishment of a tumor-associated fibroblast associated gene score based on scRNA-seq to predict prognosis in patients with triple-negative breast cancer

The tumor microenvironment (TME) is emerging as a tool for the development of improved patient prognosis and the development of novel antitumor drugs. As the most important stromal cells in the tumor microenvironment, cancer-associated fibroblasts (CAFs) play an important role in the development of TNBC. The rise of single-cell sequencing technology has facilitated our study of the various cell types in TME. In this study, we interpreted the heterogeneity of TNBCs from the perspective of tumor-associated fibroblasts in the tumor microenvironment based on the TNBC single-cell sequencing dataset GSE118389, in the hope of providing help for individualised treatment. Combining the TCGA database and the GSE103091 dataset, four genes associated with CAFs in TNBC (CERCAM, KLF10, ECM1,HGF) were identified using the R package Seurat as well as correlation consensus clustering analysis. Meanwhile, qRT-PCR, WB and IHC experiments confirmed their expression in TNBC. Based on these genes, CAFs Score was established and validated to correlate with the prognosis of patients with TNBC, with patients in the high score group surviving significantly worse than those in the low score group (P<0.001). In addition, there were significant differences in immune cell infiltration and expression of immune checkpoints between the high and low scoring groups. Compared to Stage I & II, the CAFs Score was higher in Stage III & IV TNBC patients (P = 0.043) and higher in N1-3 TNBC patients than in N0 TNBC patients (P = 0.035). EMT scores were higher within the high CAFs Score group (P = 1.4e-11) and there was a positive correlation between Stemness Score and CAFs Score (R = 0.61, P = 3.6e-09). Drug sensitivity analysis combining the GSE128099 showed a higher sensitivity to Gemcitabine in the low CAFs Score group (P = 0.0048). We speculate that these four CAFs-related genes are likely to be involved in regulating gemcitabine resistance in TNBC patients.

Extracellular Matrix Components and Mechanosensing Pathways in Health and Disease

Glycosaminoglycans (GAGs) and proteoglycans (PGs) are essential components of the extracellular matrix (ECM) with pivotal roles in cellular mechanosensing pathways. GAGs, such as heparan sulfate (HS) and chondroitin sulfate (CS), interact with various cell surface receptors, including integrins and receptor tyrosine kinases, to modulate cellular responses to mechanical stimuli. PGs, comprising a core protein with covalently attached GAG chains, serve as dynamic regulators of tissue mechanics and cell behavior, thereby playing a crucial role in maintaining tissue homeostasis. Dysregulation of GAG/PG-mediated mechanosensing pathways is implicated in numerous pathological conditions, including cancer and inflammation. Understanding the intricate mechanisms by which GAGs and PGs modulate cellular responses to mechanical forces holds promise for developing novel therapeutic strategies targeting mechanotransduction pathways in disease. This comprehensive overview underscores the importance of GAGs and PGs as key mediators of mechanosensing in maintaining tissue homeostasis and their potential as therapeutic targets for mitigating mechano-driven pathologies, focusing on cancer and inflammation.

Rationally designed β-cyclodextrin-crosslinked polyacrylamide hydrogels for cell spheroid formation and 3D tumor model construction

In vitro tumor models are essential for understanding tumor behavior and evaluating tumor biological properties. Hydrogels that can mimic the tumor extracellular matrix have become popular for creating 3D in vitro tumor models. However, designing biocompatible hydrogels with appropriate chemical and physical properties for constructing tumor models is still a challenge. In this study, we synthesized a series of β-cyclodextrin (β-CD)-crosslinked polyacrylamide hydrogels with different β-CD densities and mechanical properties and evaluated their potential for use in 3D in vitro tumor model construction, including cell capture and spheroid formation. By utilizing a combination of β-CD-methacrylate (CD-MA) and a small amount of N,N'-methylene bisacrylamide (BIS) as hydrogel crosslinkers and optimizing the CD-MA/BIS ratio, the hydrogels performed excellently for tumor cell 3D culture and spheroid formation. Notably, when we co-cultured L929 fibroblasts with HeLa tumor cells on the hydrogel surface, co-cultured spheroids were formed, showing that the hydrogel can mimic the complexity of the tumor extracellular matrix. This comprehensive investigation of the relationship between hydrogel mechanical properties and biocompatibility provides important insights for hydrogel-based in vitro tumor modeling and advances our understanding of the mechanisms underlying tumor growth and progression.

The Multifaceted Role of Neutrophils in NSCLC in the Era of Immune Checkpoint Inhibitors

Lung cancer is the most common cause of cancer-related death in both males and females in the U.S. and non-small-cell lung cancer (NSCLC) accounts for 85%. Although the use of first- or second-line immune checkpoint inhibitors (ICIs) exhibits remarkable clinical benefits, resistance to ICIs develops over time and dampens the efficacy of ICIs in patients. Tumor-associated neutrophils (TANs) have an important role in modulating the tumor microenvironment (TME) and tumor immune response. The major challenge in the field is to characterize the TANs in NSCLC TME and understand the link between TAN-related immunosuppression with ICI treatment response. In this review, we summarize the current studies of neutrophil interaction with malignant cells, T-cells, and other components in the TME. Ongoing clinical trials are aimed at utilizing reagents that have putative effects on tumor-associated neutrophils, in combination with ICI. Elevated neutrophil populations and neutrophil-associated factors could be potential therapeutic targets to enhance anti-PD1 treatment in NSCLC.

Spon1+ inflammatory monocytes promote collagen remodeling and lung cancer metastasis through lipoprotein receptor 8 signaling

Lung cancer is the leading cause of cancer-related deaths in the world, and non-small cell lung cancer (NSCLC) is the most common subset. We previously found that infiltration of tumor inflammatory monocytes (TIMs) into lung squamous carcinoma (LUSC) tumors is associated with increased metastases and poor survival. To further understand how TIMs promote metastases, we compared RNA-Seq profiles of TIMs from several LUSC metastatic models with inflammatory monocytes (IMs) of non-tumor-bearing controls. We identified Spon1 as upregulated in TIMs and found that Spon1 expression in LUSC tumors corresponded with poor survival and enrichment of collagen extracellular matrix signatures. We observed SPON1+ TIMs mediate their effects directly through LRP8 on NSCLC cells, which resulted in TGF-β1 activation and robust production of fibrillar collagens. Using several orthogonal approaches, we demonstrated that SPON1+ TIMs were sufficient to promote NSCLC metastases. Additionally, we found that Spon1 loss in the host, or Lrp8 loss in cancer cells, resulted in a significant decrease of both high-density collagen matrices and metastases. Finally, we confirmed the relevance of the SPON1/LRP8/TGF-β1 axis with collagen production and survival in patients with NSCLC. Taken together, our study describes how SPON1+ TIMs promote collagen remodeling and NSCLC metastases through an LRP8/TGF-β1 signaling axis.

Tumor-to-stroma cd8+ t cells ratio combined with cancer-associated fibroblasts: an innovative approach to predicting lymph node metastases of cervical cancer

PURPOSE

Precise identification of lymph node metastases is vital for the management of cervical cancer. However, the existing diagnostic methods for lymph node metastases have certain drawbacks. In this study, we aim to explore the expression of cancer-associated fibroblasts (CAFs) and tumor-to-stroma CD8+ T cells ratio (CD8+ T cells T:S ratio) and its association with lymph node metastases of cervical cancer.

METHODS

Hundred and ten cervical cancer tissues and 39 biopsy tissues from patients were investigated immunocytochemically for the expression of CAFs and CD8+ T cells. The statistical correlation analysis was carried out using the SPSS system.

RESULTS

A strong and statistically significant negative correlation (r= - 0.690; P < 0.001) was observed between CAF density and CD8+ T cells T:S ratio. Not only were CAFs density and CD8+ T cells T:S ratio correlated with lymph node metastases respectively (P < 0.001), but the combination of them also significantly correlated with lymph node metastases (P < 0.001). Then, we constructed the combined diagnosis model (Logit (P) = - 4.446 + 0.300 × CAFs + 0.752 × CD8+ T cells T:S Ratio) of cervical cancer lymph node metastases. ROC curves analysis showed that the ROC curves areas for CAFs, CD8+ T cells T:S ratio, and a combination of both are 0.879, 0.747, and 0.951. Then, the prediction model was verified by biopsy specimens and consistent results were obtained.

CONCLUSIONS

The combination of CAF density and CD8+ T cells T:S ratio has a significant predictive value for lymph node metastases in patients with cervical cancer.

Hierarchically Released Liquid Metal Nanoparticles for Mild Photothermal Therapy/Chemotherapy of Breast Cancer Bone Metastases via Remodeling Tumor Stromal Microenvironment

Currently, the treatment strategy for bone metastasis is mainly to inhibit the growth of tumor cells and the activity of osteoclasts, while ignoring the influence of the tumor stromal microenvironment (TSM) on the progression of bone metastasis. Herein, a dual-target liquid metal (LM)-based drug delivery system (DDS) with favorable photothermal performance is designed to spatially program the delivery of multiple therapeutic agents to enhance the treatment of bone metastasis through TSM remodeling. Briefly, mesoporous silicon-coated LM is integrated into zeolitic imidazolate framework-8 (ZIF-8) with both bone-seeking and tumor-targeting capacities. Curcumin (Cur), a tumor microenvironment modulator, is encapsulated into ZIF-8, and doxorubicin (DOX) is enclosed inside mesoporous silicon. Specific accumulation of the LM-based DDS in bone metastases first relieves the tumor stroma by releasing Cur in response to the acidic tumor microenvironment and then releases DOX deep into the tumor under near-infrared light irradiation. The combined strategy of the LM-based DDS and mild photothermal therapy has been shown to effectively restrain cross-talk between osteoclasts and tumor cells by inhibiting the secretion of transforming growth factor-β, degrading extracellular matrix components, and increasing infiltration of CD4+ and CD8+ T cells, which provides a promising strategy for the treatment of bone metastases.

Advances in immunotherapy for triple-negative breast cancer

BACKGROUND

Immunotherapy has recently emerged as a treatment strategy which stimulates the human immune system to kill tumor cells. Tumor immunotherapy is based on immune editing, which enhances the antigenicity of tumor cells and increases the tumoricidal effect of immune cells. It also suppresses immunosuppressive molecules, activates or restores immune system function, enhances anti-tumor immune responses, and inhibits the growth f tumor cell. This offers the possibility of reducing mortality in triple-negative breast cancer (TNBC).

MAIN BODY

Immunotherapy approaches for TNBC have been diversified in recent years, with breakthroughs in the treatment of this entity. Research on immune checkpoint inhibitors (ICIs) has made it possible to identify different molecular subtypes and formulate individualized immunotherapy schedules. This review highlights the unique tumor microenvironment of TNBC and integrates and analyzes the advances in ICI therapy. It also discusses strategies for the combination of ICIs with chemotherapy, radiation therapy, targeted therapy, and emerging treatment methods such as nanotechnology, ribonucleic acid vaccines, and gene therapy. Currently, numerous ongoing or completed clinical trials are exploring the utilization of immunotherapy in conjunction with existing treatment modalities for TNBC. The objective of these investigations is to assess the effectiveness of various combined immunotherapy approaches and determine the most effective treatment regimens for patients with TNBC.

CONCLUSION

This review provides insights into the approaches used to overcome drug resistance in immunotherapy, and explores the directions of immunotherapy development in the treatment of TNBC.

Integrative analysis of cancer-associated fibroblast signature in gastric cancer

Background

CAFs regulate the signaling of GC cells by promoting their migration, invasion, and proliferation and the function of immune cells as well as their location and migration in the TME by remodeling the extracellular matrix (ECM). This study explored the understanding of the heterogeneity of CAFs in TME and laid the groundwork for GC biomarker and precision treatment development.

Methods

The scRNA-seq and bulk RNA-seq datasets were obtained from GEO and TCGA. The prognostic significance of various CAFs subtypes was investigated using ssGSEA combined with Kaplan-Meier analysis. POSTN expression in GC tissues and CAFs was detected using immunohistochemistry, immunofluorescence, and Western blotting. Differential expression analysis identified the differentially expressed genes (DEGs) between normal and tumor samples in TCGA-STAD. Pearson correlation analysis identified DEGs associated with adverse prognosis CAF subtype, and univariate Cox regression analysis determined prognostic genes associated with CAFs. LASSO regression analysis and Multivariate Cox regression were used to build a prognosis model for CAFs.

Results

We identified five CAFs subtypes in GC, with the CAF_0 subtype associated with poor prognosis. The abundance of CAF_0 correlated with T stage, clinical stage, histological type, and immune cell infiltration levels. Periostin (POSTN) exhibited increased expression in both GC tissues and CAFs and was linked to poor prognosis in GC patients. Through LASSO and multivariate Cox regression analysis, three genes (CXCR4, MATN3, and KIF24) were selected to create the CAFs-score. We developed a nomogram to facilitate the clinical application of the CAFs-score. Notably, the CAFs signature showed significant correlations with immune cells, stromal components, and immunological scores, suggesting its pivotal role in the tumor microenvironment (TME). Furthermore, CAFs-score demonstrated prognostic value in assessing immunotherapy outcomes, highlighting its potential as a valuable biomarker to guide therapeutic decisions.

Conclusion

CAF_0 subtype in TME is the cause of poor prognosis in GC patients. Furthermore, CAFs-score constructed from the CAF_0 subtype can be used to determine the clinical prognosis, immune infiltration, clinicopathological characteristics, and assessment of personalized treatment of GC patients.

Lysyl oxidase-responsive anchoring nanoparticles for modulation of the tumor immune microenvironment

In the tumor microenvironment, lysyl oxidase (LOX) is known to play a key role in stabilizing the tumor extracellular matrix. Here, we designed LOX-responsive nanoparticles to interact with the collagen matrix of the tumor microenvironment. Collagen-coated and imiquimod-loaded polydopamine nanoparticles (CPN/IQ) could form crosslinked structures with the collagen matrix via LOX. In vitro, anchoring of CPN/IQ nanoparticles was observed with LOX-secreting CT26 cells, but this was blocked by a LOX inhibitor. In CT26 tumor-bearing mice, co-administration of nanoparticles plus the LOX inhibitor did not significantly alter the antitumor efficacy among nanoparticles. In the absence of the LOX inhibitor, however, a single administration of CPN/IQ could provide sustained responsiveness to near-infrared irradiation and ablation of primary tumors. In the primary tumor microenvironment, CPN/IQ lowered the Treg cell population but increased the cytotoxic CD3+CD8+ T cell population. In splenic dendritic cells, CPN/IQ treatment significantly increased the CD11c+CD86+ and CD11c+CD80+ cell populations. In a CT26 distant tumor-rechallenge model, CPN/IQ treatment increased the cytotoxic CD3+CD8+ T cell population and provided 100% survival of mice until 64 days. This study indicates the feasibility of tumor immune microenvironment modulation using LOX-responsive size-transforming nanoparticles. Although we tested the concept in a CT26 cell-derived tumor model, the concept of LOX-responsive collagen matrix- anchoring nanoparticles may be broadly applied to other tumor tissues with LOX-rich tumor microenvironments.

Dissecting the functions of cancer-associated fibroblasts to therapeutically target head and neck cancer microenvironment

Head and neck cancers (HNC) are a diverse group of aggressive malignancies with high morbidity and mortality, leading to almost half-million deaths annually worldwide. A better understanding of the molecular processes governing tumor formation and progression is crucial to improve current diagnostic and prognostic tools as well as to develop more personalized treatment strategies. Tumors are highly complex and heterogeneous structures in which growth and dissemination is not only governed by the cancer cells intrinsic mechanisms, but also by the surrounding tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs) emerge as predominant TME components and key players in the generation of permissive conditions that ultimately impact in tumor progression and metastatic dissemination. Although CAFs were initially considered a consequence of tumor development, it is now well established that they actively contribute to numerous cancer hallmarks i.e., tumor cell growth, migration and invasion, cancer cell stemness, angiogenesis, metabolic reprograming, inflammation, and immune system modulation. In this scenario, therapeutic strategies targeting CAF functions could potentially have a major impact in cancer therapeutics, providing avenues for new treatment options or for improving efficacy in established approaches. This review is focused on thoroughly dissecting existing evidences supporting the contribution of CAFs in HNC biology with an emphasis on current knowledge of the key molecules and pathways involved in CAF-tumor crosstalk, and their potential as novel biomarkers and/or therapeutic targets to effectively interfere the tumor-stroma crosstalk for HNC patients benefit. involved in CAF-tumor crosstalk, and their potential as novel biomarkers and/or therapeutic targets to effec- tively interfere the tumor-stroma crosstalk for HNC patients benefit.

Oncolytic virotherapy: basic principles, recent advances and future directions

Oncolytic viruses (OVs) have attracted growing awareness in the twenty-first century, as they are generally considered to have direct oncolysis and cancer immune effects. With the progress in genetic engineering technology, OVs have been adopted as versatile platforms for developing novel antitumor strategies, used alone or in combination with other therapies. Recent studies have yielded eye-catching results that delineate the promising clinical outcomes that OVs would bring about in the future. In this review, we summarized the basic principles of OVs in terms of their classifications, as well as the recent advances in OV-modification strategies based on their characteristics, biofunctions, and cancer hallmarks. Candidate OVs are expected to be designed as "qualified soldiers" first by improving target fidelity and safety, and then equipped with "cold weapons" for a proper cytocidal effect, "hot weapons" capable of activating cancer immunotherapy, or "auxiliary weapons" by harnessing tactics such as anti-angiogenesis, reversed metabolic reprogramming and decomposing extracellular matrix around tumors. Combinations with other cancer therapeutic agents have also been elaborated to show encouraging antitumor effects. Robust results from clinical trials using OV as a treatment congruously suggested its significance in future application directions and challenges in developing OVs as novel weapons for tactical decisions in cancer treatment.

Cellular landscape of tumour microenvironment in prostate cancer

Prostate cancer is still a public health priority in men and the impact of this disease will be more pronounced with the ageing of the world's population. Clinical heterogeneity of prostate cancer is reflected in spatial and clonal genomic diversity. Accumulating evidence demonstrates that the malignant behaviour of cancer is not only attributed to cancer cells but also fundamentally affected by stromal activity and controlled by various mechanisms of the tumour microenvironment. Data on prostate cancer in this study was derived from seven GEO datasets and the TCGA database. We analyzed the tumour microenvironment of prostate cancer in terms of clinical process, T stage and Gleason score using EPIC and xCell algorithms. We also analyzed the common immune checkpoints. In this study, we confirmed remarkable tumour tissue remodelling in the development of prostate cancer and further demonstrated the importance of cancer-related fibroblasts in the biochemical recurrence and metastasis for patients with prostate cancer undergoing radical radiotherapy or prostatectomy. In addition, we found that NRP1, CD200, TNFSF18 and CD80 might be the potential targets for prostate cancer.

Targeting the tumor stroma for cancer therapy

Tumors are comprised of both cancer cells and surrounding stromal components. As an essential part of the tumor microenvironment, the tumor stroma is highly dynamic, heterogeneous and commonly tumor-type specific, and it mainly includes noncellular compositions such as the extracellular matrix and the unique cancer-associated vascular system as well as a wide variety of cellular components including activated cancer-associated fibroblasts, mesenchymal stromal cells, pericytes. All these elements operate with each other in a coordinated fashion and collectively promote cancer initiation, progression, metastasis and therapeutic resistance. Over the past few decades, numerous studies have been conducted to study the interaction and crosstalk between stromal components and neoplastic cells. Meanwhile, we have also witnessed an exponential increase in the investigation and recognition of the critical roles of tumor stroma in solid tumors. A series of clinical trials targeting the tumor stroma have been launched continually. In this review, we introduce and discuss current advances in the understanding of various stromal elements and their roles in cancers. We also elaborate on potential novel approaches for tumor-stroma-based therapeutic targeting, with the aim to promote the leap from bench to bedside.

Invasion-Associated Reorganization of Laminin 332 in Oral Squamous Cell Carcinomas: The Role of the Laminin γ2 Chain in Tumor Biology, Diagnosis, and Therapy

Simple Summary

The destructive growth of carcinomas is associated with crossing the border between the epithelial and the connective tissue parts of an organ. One component of this borderline, the basement membrane, is the heterotrimeric laminin 332, which mediates the adhesion of basal epithelial cells. This protein, in particular its gamma 2 chain, is fundamentally reorganized during tumor cell invasion. Specific deposition patterns of laminin 332 are also present in oral squamous cell carcinomas and have been shown to be of high diagnostic and predictive value. Furthermore, laminin 332 restructuring is associated with important tumor biological processes, e.g., stromal activation, the development of a motile phenotype, and tumor spreading. In this review, current knowledge in the field is summarized and the recommendation to consider laminin 332 as a promising grading and monitoring parameter and as a potential therapeutic target is discussed.

Abstract

Invasion of the connective tissue by carcinoma cells is accompanied by disintegration and reorganization of the hemidesmosomes, which connect the basement membrane to the basal epithelial cells. In terms of mediating the basement membrane, i.e., basal cell interactions, the heterotrimeric laminin 332 is the most important bridging molecule. Due to this distinct function, laminin 332, especially its gamma 2 chain, came into the focus of cancer research. Specific de novo synthesis and deposition patterns of laminin 332 are evident upon development and progression of oral squamous cell carcinomas (OSCCs). Loss from the basement membrane, cytoplasmic accumulation, and extracellular deposition are associated with crucial processes such as stromal activation and immune response, epithelial to mesenchymal transition, and tumor cell budding. In networks with components of the tumor microenvironment, altered expression of laminin 332 chains, proteolytic processing, and interaction with integrin receptors seem to promote cancer cell migration. Indeed, reorganization patterns are shown to have a high diagnostic and prognostic value. Here, we summarize the current knowledge on laminin 332 reorganization in OSCCs with special focus on its gamma 2 chain and provide, based on the current literature, evidence on its promising role as a grading and monitoring parameter and as a potential therapeutic target.

Extracellular matrix mechanobiology in cancer cell migration

The extracellular matrix (ECM) is pivotal in modulating tumor progression. Besides chemically stimulating tumor cells, it also offers physical support that orchestrates the sequence of events in the metastatic cascade upon dynamically modulating cell mechanosensation. Understanding this translation between matrix biophysical cues and intracellular signaling has led to rapid growth in the interdisciplinary field of cancer mechanobiology in the last decade. Substantial efforts have been made to develop novel in vitro tumor mimicking platforms to visualize and quantify the mechanical forces within the tissue that dictate tumor cell invasion and metastatic growth. This review highlights recent findings on tumor matrix biophysical cues such as fibrillar arrangement, crosslinking density, confinement, rigidity, topography, and non-linear mechanics and their implications on tumor cell behavior. We also emphasize how perturbations in these cues alter cellular mechanisms of mechanotransduction, consequently enhancing malignancy. Finally, we elucidate engineering techniques to individually emulate the mechanical properties of tumors that could help serve as toolkits for developing and testing ECM-targeted therapeutics on novel bioengineered tumor platforms. STATEMENT OF SIGNIFICANCE: Disrupted ECM mechanics is a driving force for transitioning incipient cells to life-threatening malignant variants. Understanding these ECM changes can be crucial as they may aid in developing several efficacious drugs that not only focus on inducing cytotoxic effects but also target specific matrix mechanical cues that support and enhance tumor invasiveness. Designing and implementing an optimal tumor mimic can allow us to predictively map biophysical cue-modulated cell behaviors and facilitate the design of improved lab-grown tumor models with accurately controlled structural features. This review focuses on the abnormal changes within the ECM during tumorigenesis and its implications on tumor cell-matrix mechanoreciprocity. Additionally, it accentuates engineering approaches to produce ECM features of varying levels of complexity which is critical for improving the efficiency of current engineered tumor tissue models.

Tumor-targeted miRNA nanomedicine for overcoming challenges in immunity and therapeutic resistance

miRNA are critical messengers in the tumor microenvironment (TME) that influence various processes leading to immune suppression, tumor progression, metastasis and resistance. Strategies to modulate miRNAs in the TME have important implications in overcoming these challenges. However, miR delivery to specific cells in the TME has been challenging. This review discusses nanomedicine strategies to achieve cell-specific delivery of miRNAs. The key goal of delivery is to activate the tumor immune landscape as well as to prevent chemotherapy resistance. Specifically, the use of hyaluronic acid-based nanoparticle miRNA delivery to the TME is discussed. The discussion is focused on miRNA-125b for reprogramming tumor-associated macrophages to overcome immunosuppression and miRNA-let-7b to overcome resistance to anticancer chemotherapeutics because both these miRNAs have been extensively evaluated for delivery with hyaluronic acid-based delivery systems.

Downregulated Dual-Specificity Protein Phosphatase 1 in Ovarian Carcinoma: A Comprehensive Study With Multiple Methods

Introduction: We aimed to explore the abnormal expression of dual-specificity protein phosphatase 1 (DUSP1) and its latent molecular mechanisms in ovarian carcinoma (OVCA).

Materials and Methods: Two clinical cohorts collected from two different hospitals were used to evaluate the expression of DUSP1 protein in OVCA tissues. RNA-sequencing and microarray datasets were utilised to verify DUSP1 expression at mRNA levels in both OVCA tissues and in the peripheral blood of OVCA patients. Furthermore, an integrated calculation was performed to pool the standard mean difference (SMD) from each cohort in order to comprehensively assess the expression of DUSP1 in OVCA. Furthermore, we examined the relationship among DUSP1, tumour microenvironment (TME), and chemotherapy resistance in OVCA. Moreover, we used pathway enrichment analysis to explore the underlying mechanisms of DUSP1 in OVCA.

Results: A pooled SMD of −1.19 (95% CI [−2.00, −0.38], p = 0.004) with 1,240 samples revealed that DUSP1 was downregulated in OVCA at both mRNA and protein levels. The area under the receiver operating characteristic curve of 0.9235 indicated the downregulated DUSP1 in peripheral blood may have a non-invasive diagnostic value in OVCA. Through six algorithms, we identified that DUSP1 may related to tumour-infiltrating T cells and cancer associated fibroblasts (CAFs) in OVCA. Pathway enrichment demonstrated that DUSP1 might participate in the mitogen-activated protein kinase (MAPK) signalling pathway. Furthermore, DUSP1 may have relations with chemotherapy resistance, and a favourable combining affinity was observed in the paclitaxel-DUSP1 docking model.

Conclusion: DUSP1 was downregulated in OVCA, and this decreasing trend may affect the infiltration of CAFs. Finally, DUSP1 may have a targeting relation with paclitaxel and participate in MAPK signaling pathways.

Combining Immune-Related Genes For Delineating the Extracellular Matrix and Predicting Hormone Therapy and Neoadjuvant Chemotherapy Benefits In Breast Cancer

Breast cancer (BC) is the most prevalent cancer in women worldwide. A systematic approach to BC treatment, comprising adjuvant and neoadjuvant chemotherapy (NAC), as well as hormone therapy, forms the foundation of the disease’s therapeutic strategy. The extracellular matrix (ECM) is a dynamic network that exerts a robust biological effect on the tumor microenvironment (TME), and it is highly regulated by several immunological components, such as chemokines and cytokines. It has been established that the ECM promotes the development of an immunosuppressive TME. Therefore, while analyzing the ECM of BC, immune-related genes must be considered. In this study, we used bioinformatic approaches to identify the most valuable ECM-related immune genes. We used weighted gene co-expression network analysis to identify the immune-related genes that potentially regulate the ECM and then combined them with the original ECM-related gene set for further analysis. Least absolute shrinkage and selection operator (LASSO) regression and SurvivalRandomForest were used to narrow our ECM-related gene list and establish an ECM index (ECMI) to better delineate the ECM signature. We stratified BC patients into ECMI high and low groups and evaluated their clinical, biological, and genomic characteristics. We found that the ECMI is highly correlated with long-term BC survival. In terms of the biological process, this index is positively associated with the cell cycle, DNA damage repair, and homologous recombination but negatively with processes involved in angiogenesis and epithelial–mesenchymal transition. Furthermore, the tumor mutational burden, copy number variation, and DNA methylation levels were found to be related to the ECMI. In the Metabric cohort, we demonstrated that hormone therapy is more effective in patients with a low ECMI. Additionally, differentially expressed genes from the ECM-related gene list were extracted from patients with a pathologic complete response (pCR) to NAC and with residual disease (RD) to construct a neural network model for predicting the chance of achieving pCR individually. Finally, we performed qRT-PCR to validate our findings and demonstrate the important role of the gene OGN in predicting the pCR rate. In conclusion, delineation of the ECM signature with immune-related genes is anticipated to aid in the prediction of the prognosis of patients with BC and the benefits of hormone therapy and NAC in BC patients.

Low-dose X-ray irradiation combined with FAK inhibitors improves the immune microenvironment and confers sensitivity to radiotherapy in pancreatic cancer

Radiation therapy offers limited clinical benefits for patients with pancreatic cancer, partly as a result of the predominantly immunosuppressive microenvironment characteristic of this specific type of cancer. A large number of abnormal blood vessels and high-density fibrous matrices in pancreatic cancer will lead to hypoxia within tumor tissue and hinder immune cell infiltration. We used low-dose X-ray irradiation, also known as low-dose radiation therapy (LDRT), to normalize the blood vessels in pancreatic cancer, while simultaneously administering an inhibitor of focal adhesion kinase (FAK) to reduce pancreatic cancer fibrosis. We found that this treatment successfully reduced pancreatic cancer hypoxia, increased immune cell infiltration, and increased sensitivity to radiation therapy for pancreatic cancer.

Targeting Tumour-Associated Fibroblasts in Cancers

Tumours develop within complex tissue environments consisting of aberrant oncogenic cancer cells, diverse innate and adaptive immune cells, along with structural stromal cells, extracellular matrix and vascular networks, and many other cellular and non-cellular soluble constituents. Understanding the heterogeneity and the complex interplay between these cells remains a key barrier in treating tumours and cancers. The immune status of the pre-tumour and tumour milieu can dictate if the tumour microenvironment (TME) supports either a pro-malignancy or an anti-malignancy phenotype. Identification of the factors and cell types that regulate the dysfunction of the TME is crucial in order to understand and modulate the immune status of tumours. Among these cell types, tumour-associated fibroblasts are emerging as a major component of the TME that is often correlated with poor prognosis and therapy resistance, including immunotherapies. Thus, a deeper understanding of the complex roles of tumour-associated fibroblasts in regulating tumour immunity and cancer therapy could provide new insight into targeting the TME in various human cancers. In this review, we summarize recent studies investigating the role of immune and key stromal cells in regulating the immune status of the TME and discuss the therapeutic potential of targeting stromal cells, especially tumour-associated fibroblasts, within the TME as an adjuvant therapy to sensitize immunosuppressive tumours and prevent cancer progression, chemo-resistance and metastasis.

Fibrotic activity quantified in serum by measurements of type III collagen pro-peptides can be used for prognosis across different solid tumor types

Due to activation of fibroblast into cancer-associated fibroblasts, there is often an increased deposition of extracellular matrix and fibrillar collagens, e.g. type III collagen, in the tumor microenvironment (TME) that leads to tumor fibrosis (desmoplasia). Tumor fibrosis is closely associated with treatment response and poor prognosis for patients with solid tumors. To assure that the best possible treatment option is provided for patients, there is medical need for identifying patients with high (or low) fibrotic activity in the TME. Measuring unique collagen fragments such as the pro-peptides released into the bloodstream during fibrillar collagen deposition in the TME can provide a non-invasive measure of the fibrotic activity. Based on data from 8 previously published cohorts, this review provides insight into the prognostic value of quantifying tumor fibrosis by measuring the pro-peptide of type III collagen in serum of a total of 1692 patients with different solid tumor types and discusses the importance of tumor fibrosis for understanding prognosis and for potentially guiding future drug development efforts that aim at overcoming the poor outcome associated with a fibrotic TME.

An Overview of the Role of Mechanical Stretching in the Progression of Lung Cancer

Cells and tissues in the human body are subjected to mechanical forces of varying degrees, such as tension or pressure. During tumorigenesis, physical factors, especially mechanical factors, are involved in tumor development. As lung tissue is influenced by movements associated with breathing, it is constantly subjected to cyclical stretching and retraction; therefore, lung cancer cells and lung cancer-associated fibroblasts (CAFs) are constantly exposed to mechanical load. Thus, to better explore the mechanisms involved in lung cancer progression, it is necessary to consider factors involved in cell mechanics, which may provide a more comprehensive analysis of tumorigenesis. The purpose of this review is: 1) to provide an overview of the anatomy and tissue characteristics of the lung and the presence of mechanical stimulation; 2) to summarize the role of mechanical stretching in the progression of lung cancer; and 3) to describe the relationship between mechanical stretching and the lung cancer microenvironment, especially CAFs.

In vitro fibroblasts viability and migration stimulation of Acalypha indica: an insight on wound healing activity

Background

The current study investigates the antioxidant activity of Acalypha indica aerial parts and root ethanolic extracts and explore whether these extracts will stimulate fibroblasts viability and ability to migrate.

Results

Aerial parts extract exhibited higher DPPH scavenging activity compared to root extract with IC50 of 62 µg/mL and 206 µg/mL, respectively. Both aerial parts and root extracts showed low cytotoxicity towards fibroblasts with 753 µg/mL LD50 for aerial parts and undetected LD50 for root extract. Additionally, aerial parts extract significantly induces fibroblasts proliferation up to 134%. Wound closure investigation showed a significant closure percentage for aerial parts compared to untreated control with 75% at 1 µg/mL and high closure percentage with 70% at 0.1 µg/mL for root extract compared to only 59% closure percentage for untreated control after 48 h of the study.

Conclusions

This study provided evidence for A. indica to have great wound healing potential. The finding builds the scientific background in future to utilise the high antioxidant activity of A. indica and its ability to stimulate fibroblasts migration and proliferation for further applications.

The Role of Decorin and Biglycan Signaling in Tumorigenesis

The complex and adaptive nature of malignant neoplasm constitute a major challenge for the development of effective anti-oncogenic therapies. Emerging evidence has uncovered the pivotal functions exerted by the small leucine-rich proteoglycans, decorin and biglycan, in affecting tumor growth and progression. In their soluble forms, decorin and biglycan act as powerful signaling molecules. By receptor-mediated signal transduction, both proteoglycans modulate key processes vital for tumor initiation and progression, such as autophagy, inflammation, cell-cycle, apoptosis, and angiogenesis. Despite of their structural homology, these two proteoglycans interact with distinct cell surface receptors and thus modulate distinct signaling pathways that ultimately affect cancer development. In this review, we summarize growing evidence for the complex roles of decorin and biglycan signaling in tumor biology and address potential novel therapeutic implications.

Oral submucous fibrosis stimulates invasion and epithelial-mesenchymal transition in oral squamous cell carcinoma by activating MMP-2 and IGF-IR

Oral submucous fibrosis (OSF) involves a high risk of malignant transformation and has been implicated in oral cancer. Limited studies have been conducted on the role of OSF in relation to the invasive capabilities and epithelial-mesenchymal transition (EMT) in oral cancer. Herein, we investigated the effects of OSF on the microenvironment of human oral cancer cells. The results showed that the conditioned medium (CM) of fibrotic buccal mucosal fibroblasts (fBMFs) strongly induced the invasion of oral cancer cells and increased the activities of matrix metalloproteinase-2. OSF significantly induced the EMT in oral cancer cells and downregulated epithelial markers, such as E-cadherin, but significantly elevated vimentin, fibronectin, N-cadherin, RhoA, Rac-1 and FAK. Insulin-like growth factor-1 (IGF-1) was elevated in OSF. The protein levels of the IGF-1R were upregulated specifically in fBMF CM treatment for oral cancer cells, and the IGFR gene was confirmed by The Cancer Genome Atlas patient transcriptome data. The Kaplan-Meier curve analysis revealed that patients with oral squamous cell carcinoma and high IGFR expression levels had poorer 5-year survival than those with low IGFR expression (p = 0.004). The fBMF-stimulated EMT cell model may recapture some of the molecular changes during EMT progression in clinical patients with oral cancer.

3D Cancer Models: Depicting Cellular Crosstalk within the Tumour Microenvironment

The tumour microenvironment plays a critical role in tumour progression and drug resistance processes. Non-malignant cell players, such as fibroblasts, endothelial cells, immune cells and others, interact with each other and with the tumour cells, shaping the disease. Though the role of each cell type and cell communication mechanisms have been progressively studied, the complexity of this cellular network and its role in disease mechanism and therapeutic response are still being unveiled. Animal models have been mainly used, as they can represent systemic interactions and conditions, though they face recognized limitations in translational potential due to interspecies differences. In vitro 3D cancer models can surpass these limitations, by incorporating human cells, including patient-derived ones, and allowing a range of experimental designs with precise control of each tumour microenvironment element. We summarize the role of each tumour microenvironment component and review studies proposing 3D co-culture strategies of tumour cells and non-malignant cell components. Moreover, we discuss the potential of these modelling approaches to uncover potential therapeutic targets in the tumour microenvironment and assess therapeutic efficacy, current bottlenecks and perspectives.

Decreased m6A Modification of CD34/CD276(B7-H3) Leads to Immune Escape in Colon Cancer

Previous studies have reported that m6a modification promotes tumor immune escape by affecting tumor microenvironment (TME). Due to the complexity of TME, a single biomarker is insufficient to describe the complex biological characteristics of tumor and its microenvironment. Therefore, it is more meaningful to explore a group of effective biomarkers reflecting different characteristics of cancer to evaluate the biological characteristics of solid tumors. Here, the immune gene CD34/CD276 with different m6A peak was obtained by m6A sequencing (MeRIP-seq) of colon cancer (CRC)clinical samples and combined with MsIgDB database, which was used to perform cluster analysis on TCGA-COAD level 3 data. The CD34/CD276 as a molecular marker for CRC prognosis was confirmed by survival analysis and immunohistochemical assay. Further bioinformatics analysis was carried out to analyze the molecular mechanism of CD34/CD276 affecting the TME through m6a-dependent down-regulation and ultimately promoting immune escape of CRC.

ECM Remodeling in Squamous Cell Carcinoma of the Aerodigestive Tract: Pathways for Cancer Dissemination and Emerging Biomarkers

Squamous cell carcinomas (SCC) include a number of different types of tumors developing in the skin, in hollow organs, as well as the upper aerodigestive tract (UADT) including the head and neck region and the esophagus which will be dealt with in this review. These tumors are often refractory to current therapeutic approaches with poor patient outcome. The most important prognostic determinant of SCC tumors is the presence of distant metastasis, significantly correlating with low patient survival rates. Rapidly emerging evidence indicate that the extracellular matrix (ECM) composition and remodeling profoundly affect SSC metastatic dissemination. In this review, we will summarize the current knowledge on the role of ECM and its remodeling enzymes in affecting the growth and dissemination of UADT SCC. Taken together, these published evidence suggest that a thorough analysis of the ECM composition in the UADT SCC microenvironment may help disclosing the mechanism of resistance to the treatments and help defining possible targets for clinical intervention.

ECM Remodeling in Squamous Cell Carcinoma of the Aerodigestive Tract: Pathways for Cancer Dissemination and Emerging Biomarkers

Simple Summary

Local and distant metastasis of patients affected by squamous cell carcinoma of the upper aerodigestive tract predicts poor prognosis. In the latest years, the introduction of new therapeutic approaches, including targeted and immune therapies, has improved the overall survival. However, a large number of these patients do not benefit from these treatments. Thus, the identification of suitable prognostic and predictive biomarkers, as well as the discovery of new therapeutic targets have emerged as a crucial clinical need. In this context, the extracellular matrix represents a suitable target for the development of such therapeutic tools. In fact, the extracellular matrix is composed by complex molecules able to interact with a plethora of receptors and growth factors, thus modulating the dynamic crosstalk between cancer cells and the tumor microenvironment. In this review, we summarize the current knowledge of the role of the extracellular matrix in affecting squamous cell carcinoma growth and dissemination. Despite extracellular matrix is known to affect the development of many cancer types, only a restricted number of these molecules have been recognized to impact on squamous cell carcinoma progression. Thus, we consider that a thorough analysis of these molecules may be key to develop new potential therapeutic targets/biomarkers.

Abstract

Squamous cell carcinomas (SCC) include a number of different types of tumors developing in the skin, in hollow organs, as well as the upper aerodigestive tract (UADT) including the head and neck region and the esophagus which will be dealt with in this review. These tumors are often refractory to current therapeutic approaches with poor patient outcome. The most important prognostic determinant of SCC tumors is the presence of distant metastasis, significantly correlating with low patient survival rates. Rapidly emerging evidence indicate that the extracellular matrix (ECM) composition and remodeling profoundly affect SSC metastatic dissemination. In this review, we will summarize the current knowledge on the role of ECM and its remodeling enzymes in affecting the growth and dissemination of UADT SCC. Taken together, these published evidence suggest that a thorough analysis of the ECM composition in the UADT SCC microenvironment may help disclosing the mechanism of resistance to the treatments and help defining possible targets for clinical intervention.

Fibroblasts as confederates of the immune system

Fibroblastic stromal cells are as diverse, in origin and function, as the niches they fashion in the mammalian body. This cellular variety impacts the spectrum of responses elicited by the immune system. Fibroblast influence on the immune system keeps evolving our perspective on fibroblast roles and functions beyond just a passive structural part of organs. This review discusses the foundations of fibroblastic stromal-immune crosstalk, under the scope of stromal heterogeneity as a basis for tissue-specific tutoring of the immune system. Focusing on the skin as a relevant immunological organ, we detail the complex interactions between distinct fibroblast populations and immune cells that occur during homeostasis, injury repair, scarring, and disease. We further review the relevance of fibroblastic stromal cell heterogeneity and how this heterogeneity is central to regulate the immune system from its inception during embryonic development into adulthood.

Collagen molecular phenotypic switch between non-neoplastic and neoplastic canine mammary tissues

In spite of major advances over the past several decades in diagnosis and treatment, breast cancer remains a global cause of morbidity and premature death for both human and veterinary patients. Due to multiple shared clinicopathological features, dogs provide an excellent model of human breast cancer, thus, a comparative oncology approach may advance our understanding of breast cancer biology and improve patient outcomes. Despite an increasing awareness of the critical role of fibrillar collagens in breast cancer biology, tumor-permissive collagen features are still ill-defined. Here, we characterize the molecular and morphological phenotypes of type I collagen in canine mammary gland tumors. Canine mammary carcinoma samples contained longer collagen fibers as well as a greater population of wider fibers compared to non-neoplastic and adenoma samples. Furthermore, the total number of collagen cross-links enriched in the stable hydroxylysine-aldehyde derived cross-links was significantly increased in neoplastic mammary gland samples compared to non-neoplastic mammary gland tissue. The mass spectrometric analyses of type I collagen revealed that in malignant mammary tumor samples, lysine residues, in particular those in the telopeptides, were markedly over-hydroxylated in comparison to non-neoplastic mammary tissue. The extent of glycosylation of hydroxylysine residues was comparable among the groups. Consistent with these data, expression levels of genes encoding lysyl hydroxylase 2 (LH2) and its molecular chaperone FK506-binding protein 65 were both significantly increased in neoplastic samples. These alterations likely lead to an increase in the LH2-mediated stable collagen cross-links in mammary carcinoma that may promote tumor cell metastasis in these patients.

The Cancer Microenvironment: Mechanical Challenges of the Metastatic Cascade

The metastatic cascade presents a significant challenge to patient survival in the fight against cancer. As metastatic cells disseminate and colonize a secondary site, stepwise exposure to microenvironment-specific mechanical stimuli influences and protects successful metastasis. Following cancerous transformation and associated cell recruitment, the tumor microenvironment (TME) becomes a mechanically complex niche, owing to changes in extracellular matrix (ECM) stiffness and architecture. The ECM mechanically reprograms the cancer cell phenotype, priming cells for invasion. 2D and 3D hydrogel-based culture platforms approximate these environmental variables and permit investigations into tumor-dependent shifts in malignancy. Following TME modification, malignant cells must invade the local ECM, driven toward blood, and lymph vessels by sensing biochemical and biophysical gradients. Microfluidic chips recreate cancer-modified ECM tracks, empowering studies into modes of confined motility. Intravasation and extravasation consist of complex cancer-endothelial interactions that modify an otherwise submicron-scale migration. Perfused microfluidic platforms facilitate the physiological culture of endothelial cells and thus enhance the translatability of basic research into metastatic transendothelial migration. These platforms also shed light on the poorly understood circulating tumor cell, which defies adherent cell norms by surviving the shear stress of blood flow and avoiding anoikis. Metastatic cancers possess the plasticity to adapt to new mechanical conditions, permitting their invasiveness, and ensuring their survival against anomalous stimuli. Here, we review the cellular mechanics of metastasis in the context of current in vitro approaches. Advances that further expose the mechanisms underpinning the phenotypic fluidity of metastatic cancers remain central to the development of novel interventions targeting cancer.

Cancer-associated fibroblasts and their influence on tumor immunity and immunotherapy

Fibroblasts play an essential role in organogenesis and the integrity of tissue architecture and function. Growth in most solid tumors is dependent upon remodeling 'stroma', composed of cancer-associated fibroblasts (CAFs) and extracellular matrix (ECM), which plays a critical role in tumor initiation, progression, metastasis, and therapeutic resistance. Recent studies have clearly established that the potent immunosuppressive activity of stroma is a major mechanism by which stroma can promote tumor progression and confer resistance to immune-based therapies. Herein, we review recent advances in identifying the stroma-dependent mechanisms that regulate cancer-associated inflammation and antitumor immunity, in particular, the interactions between fibroblasts and immune cells. We also review the potential mechanisms by which stroma can confer resistance to immune-based therapies for solid tumors and current advancements in stroma-targeted therapies.

Significance of host heparanase in promoting tumor growth and metastasis

Heparanase, the sole heparan sulfate degrading endoglycosidase, regulates multiple biological activities that enhance tumor growth, angiogenesis and metastasis. Much of the impact of heparanase on tumor progression is related to its function in mediating tumor-host crosstalk, priming the tumor microenvironment to better support tumor growth and metastasis. We have utilized mice over-expressing (Hpa-tg) heparanase to reveal the role of host heparanase in tumor initiation, growth and metastasis. While in wild type mice tumor development in response to DMBA carcinogenesis was restricted to the mammary gland, Hpa-tg mice developed tumors also in their lungs and liver, associating with reduced survival of the tumor-bearing mice. Consistently, xenograft tumors (lymphoma, melanoma, lung carcinoma, pancreatic carcinoma) transplanted in Hpa-tg mice exhibited accelerated tumor growth and shorter survival of the tumor-bearing mice compared with wild type mice. Hpa-tg mice were also more prone to the development of metastases following intravenous or subcutaneous injection of tumor cells. In some models, the growth advantage was associated with infiltration of heparanase-high host cells into the tumors. However, in other models, heparanase-high host cells were not detected in the primary tumor, implying that the growth advantage in Hpa-tg mice is due to systemic factors. Indeed, we found that plasma from Hpa-tg mice enhanced tumor cell migration and invasion attributed to increased levels of pro-tumorigenic factors (i.e., RANKL, SPARC, MIP-2) in the plasma of Hpa-Tg vs. wild type mice. Furthermore, tumor aggressiveness and short survival time were demonstrated in wild type mice transplanted with bone marrow derived from Hpa-tg but not wild type mice. These results were attributed, among other factors, to upregulation of pro-tumorigenic (i.e., IL35+) and downregulation of anti-tumorigenic (i.e., IFN-γ+) T-cell subpopulations in the spleen, lymph nodes and blood of Hpa-tg vs. wild type mice and their increased infiltration into the primary tumor. Collectively, our results emphasize the significance of host heparanase in mediating the pro-tumorigenic and pro-metastatic interactions between the tumor cells and the host tumor microenvironment, immune cells and systemic factors.

Modulation of Immune Infiltration of Ovarian Cancer Tumor Microenvironment by Specific Subpopulations of Fibroblasts

Tumor immune infiltration plays a key role in the progression of solid tumors, including ovarian cancer, and immunotherapies are rapidly emerging as effective treatment modalities. However, the role of cancer-associated fibroblasts (CAFs), a predominant stromal constituent, in determining the tumor-immune microenvironment and modulating efficacy of immunotherapies remains poorly understood. We have conducted an extensive bioinformatic analysis of our and other publicly available ovarian cancer datasets (GSE137237, GSE132289 and GSE71340), to determine the correlation of fibroblast subtypes within the tumor microenvironment (TME) with the characteristics of tumor-immune infiltration. We identified (1) four functional modules of CAFs in ovarian cancer that are associated with the TME and metastasis of ovarian cancer, (2) immune-suppressive function of the collagen 1,3,5-expressing CAFs in primary ovarian cancer and omental metastases, and (3) consistent positive correlations between the functional modules of CAFs with anti-immune response genes and negative correlation with pro-immune response genes. Our study identifies a specific fibroblast subtype, fibroblast functional module (FFM)2, in the ovarian cancer tumor microenvironment that can potentially modulate a tumor-promoting immune microenvironment, which may be detrimental toward the effectiveness of ovarian cancer immunotherapies.

Force balancing ACT-IN the tumor microenvironment: Cytoskeletal modifications in cancer and stromal cells to promote malignancy

The tumor microenvironment is a complex milieu that dictates the growth, invasion, and metastasis of cancer cells. Both cancer and stromal cells in the tumor tissue encounter and adapt to a variety of extracellular factors, and subsequently contribute and drive the progression of the disease to more advanced stages. As the disease progresses, a small population of cancer cells becomes more invasive through a complex process known as epithelial-mesenchymal transition, and nearby stromal cells assume a carcinoma associated fibroblast phenotype characterized by enhanced migration, cell contractility, and matrix secretion with the ability to reorganize extracellular matrices. As cells transition into more malignant phenotypes their biophysical properties, controlled by the organization of cytoskeletal proteins, are altered. Actin and its associated proteins are essential modulators and facilitators of these changes. As the cells respond to the cues in the microenvironment, actin driven mechanical forces inside and outside the cells also evolve. Recent advances in biophysical techniques have enabled us to probe these actin driven changes in cancer and stromal cells and demarcate their role in driving changes in the microenvironment. Understanding the underlying biophysical mechanisms that drive cancer progression could provide critical insight on novel therapeutic approaches in the fight against cancer.

Fibroblasts: The arbiters of extracellular matrix remodeling

Extracellular matrix (ECM) is the foundation on which all cells and organs converge to orchestrate normal physiological functions. In the setting of pathology, the ECM is modified to incorporate additional roles, with modifications including turnover of existing ECM and deposition of new ECM. The fibroblast is center stage in coordinating both normal tissue homeostasis and response to disease. Understanding how fibroblasts work under normal conditions and are activated in response to injury or stress will provide mechanistic insight that triggers discovery of new therapeutic treatments for a wide range of disease. We highlight here fibroblast roles in the cancer, lung, and heart as example systems where fibroblasts are major contributors to homeostasis and pathology.