A TRACER culture invasion assay to probe the impact of cancer associated fibroblasts on head and neck squamous cell carcinoma cell invasiveness

Integrative Analysis Reveals STC2 as a Prognostic Biomarker of Laryngeal Squamous Cell Carcinoma

Stanniocalcin 2 (STC2) is involved in many tumour types, but it remains unclear what its biological function is in laryngeal squamous cell carcinoma (LSCC). Therefore, we investigated STC2's expression, potential function, and prognostic significance of in LSCC. The expression and prognosis of STC2 in LSCC were described using the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. In the TCGA database, the relationship between STC2 and immune infiltration, expression of immune cell chemokine and receptor genes, immune cell molecular marker genes, and epithelial‒mesenchymal transition (EMT) marker genes were analysed. The biological processes involved in STC2 and its expression-related genes were analysed comprehensively using bioinformatics. The single-gene ceRNA network of STC2 was constructed in the TCGA database. Finally, LSCC patients' tumour tissue STC2 expression was verified. STC2 silencing with the RNAi technique was used for the determination of cellular functions in a laryngeal cancer cell line. STC2 expression was higher in most tumours, including LSCC, than in normal tissues and was associated with poor prognosis. The relative proportions of naïve B, plasma, follicular helper T, and macrophage M0 cells in LSCC and normal samples differed significantly. STC2 expression correlated significantly positively with that of TGFB1 (biomarker of Tregs) and significantly negatively with that of D79A and CD19 (biomarkers of B cells). Furthermore, STC2 affected chemokine and receptor gene expression in immune cells. STC2 expression correlated with EMT marker gene expression in LSCC. STC2 was enriched in the PI3K/AKT signalling pathway, extracellular matrix (ECM) organisation, ECM-receptor interaction, and other tumour-related signalling pathways. STC2 was highly expressed in our clinical samples. N-cadherin and vimentin expression were decreased in the TU686 cell line after successful silencing of STC2, indicating that high STC2 expression may prompt LSCC cells to adopt a mesenchymal cell phenotype. STC2 silencing substantially reduced proliferation and migration in the TU686 cell line. STC2 may be a promising predictive biomarker for tumours, providing new approaches for LSCC diagnosis and treatment monitoring.

Crosstalk between CAFs and tumour cells in head and neck cancer

Head and neck squamous cell carcinomas (HNSCCs) are amongst the most aggressive, complex, and heterogeneous malignancies. The standard of care treatments for HNC patients include surgery, radiotherapy, chemotherapy, or their combination. However, around 50% do not benefit while suffering severe toxic side effects, costing the individuals and society. Decades have been spent to improve HNSCC treatment outcomes with only limited success. Much of the research in HNSCC treatment has focused on understanding the genetics of the HNSCC malignant cells, but it has become clear that tumour microenvironment (TME) plays an important role in the progression as well as treatment response in HNSCC. Understanding the crosstalk between cancer cells and TME is crucial for inhibiting progression and treatment resistance. Cancer-associated fibroblasts (CAFs), the predominant component of stroma in HNSCC, serve as the primary source of extra-cellular matrix (ECM) and various pro-tumoral composites in TME. The activation of CAFs in HNSCC is primarily driven by cancer cell-secreted molecules, which in turn induce phenotypic changes, elevated secretive status, and altered ECM production profile. Concurrently, CAFs play a pivotal role in modulating the cell cycle, stemness, epithelial-mesenchymal transition (EMT), and resistance to targeted and chemoradiotherapy in HNSCC cells. This modulation occurs through interactions with secreted molecules or direct contact with the ECM or CAF. Co-culture and 3D models of tumour cells and other TME cell types allows to mimic the HNSCC tumour milieu and enable modulating tumour hypoxia and reprograming cancer stem cells (CSC). This review aims to provide an update on the development of HNSCC tumour models comprising CAFs to obtain better understanding of the interaction between CAFs and tumour cells, and for providing preclinical testing platforms of current and combination with emerging therapeutics.

Bridging systems biology and tissue engineering: Unleashing the full potential of complex 3D in vitro tissue models of disease

Rapid advances in tissue engineering have resulted in more complex and physiologically relevant 3D in vitro tissue models with applications in fundamental biology and therapeutic development. However, the complexity provided by these models is often not leveraged fully due to the reductionist methods used to analyze them. Computational and mathematical models developed in the field of systems biology can address this issue. Yet, traditional systems biology has been mostly applied to simpler in vitro models with little physiological relevance and limited cellular complexity. Therefore, integrating these two inherently interdisciplinary fields can result in new insights and move both disciplines forward. In this review, we provide a systematic overview of how systems biology has been integrated with 3D in vitro tissue models and discuss key application areas where the synergies between both fields have led to important advances with potential translational impact. We then outline key directions for future research and discuss a framework for further integration between fields.

Engineering models of head and neck and oral cancers on-a-chip

Head and neck cancers (HNCs) rank as the sixth most common cancer globally and result in over 450 000 deaths annually. Despite considerable advancements in diagnostics and treatment, the 5-year survival rate for most types of HNCs remains below 50%. Poor prognoses are often attributed to tumor heterogeneity, drug resistance, and immunosuppression. These characteristics are difficult to replicate using in vitro or in vivo models, culminating in few effective approaches for early detection and therapeutic drug development. Organs-on-a-chip offer a promising avenue for studying HNCs, serving as microphysiological models that closely recapitulate the complexities of biological tissues within highly controllable microfluidic platforms. Such systems have gained interest as advanced experimental tools to investigate human pathophysiology and assess therapeutic efficacy, providing a deeper understanding of cancer pathophysiology. This review outlines current challenges and opportunities in replicating HNCs within microphysiological systems, focusing on mimicking the soft, glandular, and hard tissues of the head and neck. We further delve into the major applications of organ-on-a-chip models for HNCs, including fundamental research, drug discovery, translational approaches, and personalized medicine. This review emphasizes the integration of organs-on-a-chip into the repertoire of biological model systems available to researchers. This integration enables the exploration of unique aspects of HNCs, thereby accelerating discoveries with the potential to improve outcomes for HNC patients.

Endothelial cells metabolically regulate breast cancer invasion toward a microvessel

Breast cancer metastasis is initiated by invasion of tumor cells into the collagen type I-rich stroma to reach adjacent blood vessels. Prior work has identified that metabolic plasticity is a key requirement of tumor cell invasion into collagen. However, it remains largely unclear how blood vessels affect this relationship. Here, we developed a microfluidic platform to analyze how tumor cells invade collagen in the presence and absence of a microvascular channel. We demonstrate that endothelial cells secrete pro-migratory factors that direct tumor cell invasion toward the microvessel. Analysis of tumor cell metabolism using metabolic imaging, metabolomics, and computational flux balance analysis revealed that these changes are accompanied by increased rates of glycolysis and oxygen consumption caused by broad alterations of glucose metabolism. Indeed, restricting glucose availability decreased endothelial cell-induced tumor cell invasion. Our results suggest that endothelial cells promote tumor invasion into the stroma due, in part, to reprogramming tumor cell metabolism.

In Vitro Models of Head and Neck Cancer: From Primitive to Most Advanced

For several decades now, researchers have been trying to answer the demand of clinical oncologists to create an ideal preclinical model of head and neck squamous cell carcinoma (HNSCC) that is accessible, reproducible, and relevant. Over the past years, the development of cellular technologies has naturally allowed us to move from primitive short-lived primary 2D cell cultures to complex patient-derived 3D models that reproduce the cellular composition, architecture, mutational, or viral load of native tumor tissue. Depending on the tasks and capabilities, a scientific laboratory can choose from several types of models: primary cell cultures, immortalized cell lines, spheroids or heterospheroids, tissue engineering models, bioprinted models, organoids, tumor explants, and histocultures. HNSCC in vitro models make it possible to screen agents with potential antitumor activity, study the contribution of the tumor microenvironment to its progression and metastasis, determine the prognostic significance of individual biomarkers (including using genetic engineering methods), study the effect of viral infection on the pathogenesis of the disease, and adjust treatment tactics for a specific patient or groups of patients. Promising experimental results have created a scientific basis for the registration of several clinical studies using HNSCC in vitro models.

Heparan-6-O-Endosulfatase 2 Promotes Invasiveness of Head and Neck Squamous Carcinoma Cell Lines in Co-Cultures with Cancer-Associated Fibroblasts

Local invasiveness of head and neck squamous cell carcinoma (HNSCC) is a complex phenomenon supported by interaction of the cancer cells with the tumor microenvironment (TME). We and others have shown that cancer-associated fibroblasts (CAFs) are a component of the TME that can promote local invasion in HNSCC and other cancers. Here we report that the secretory enzyme heparan-6-O-endosulfatase 2 (Sulf-2) directly affects the CAF-supported invasion of the HNSCC cell lines SCC35 and Cal33 into Matrigel. The Sulf-2 knockout (KO) cells differ from their wild type counterparts in their spheroid growth and formation, and the Sulf-2-KO leads to decreased invasion in a spheroid co-culture model with the CAF. Next, we investigated whether a fucosylated chondroitin sulfate isolated from the sea cucumber Holothuria floridana (HfFucCS) affects the activity of the Sulf-2 enzyme. Our results show that HfFucCS not only efficiently inhibits the Sulf-2 enzymatic activity but, like the Sulf-2 knockout, inhibits Matrigel invasion of SCC35 and Cal33 cells co-cultured with primary HNSCC CAF. These findings suggest that the heparan-6-O-endosulfatases regulate local invasion and could be therapeutically targeted with the inhibitory activity of a marine glycosaminoglycan.

Proteomic characterisation of prostate cancer intercellular communication reveals cell type-selective signalling and TMSB4X-dependent fibroblast reprogramming

BACKGROUND

In prostate cancer, the tumour microenvironment (TME) represents an important regulator of disease progression and response to treatment. In the TME, cancer-associated fibroblasts (CAFs) play a key role in tumour progression, however the mechanisms underpinning fibroblast-cancer cell interactions are incompletely resolved. Here, we address this by applying cell type-specific labelling with amino acid precursors (CTAP) and mass spectrometry (MS)-based (phospho)proteomics to prostate cancer for the first time.

METHODS

Reciprocal interactions between PC3 prostate cancer cells co-cultured with WPMY-1 prostatic fibroblasts were characterised using CTAP-MS. Signalling network changes were determined using Metascape and Enrichr and visualised using Cytoscape. Thymosin β4 (TMSB4X) overexpression was achieved via retroviral transduction and assayed by ELISA. Cell motility was determined using Transwell and random cell migration assays and expression of CAF markers by indirect immunofluorescence.

RESULTS

WPMY-1 cells co-cultured with PC3s demonstrated a CAF-like phenotype, characterised by enhanced PDGFRB expression and alterations in signalling pathways regulating epithelial-mesenchymal transition, cytoskeletal organisation and cell polarisation. In contrast, co-cultured PC3 cells exhibited more modest network changes, with alterations in mTORC1 signalling and regulation of the actin cytoskeleton. The expression of the actin binding protein TMSB4X was significantly decreased in co-cultured WPMY-1 fibroblasts, and overexpression of TMSB4X in fibroblasts decreased migration of co-cultured PC3 cells, reduced fibroblast motility, and protected the fibroblasts from being educated to a CAF-like phenotype by prostate cancer cells.

CONCLUSIONS

This study highlights the potential of CTAP-MS to characterise intercellular communication within the prostate TME and identify regulators of cellular crosstalk such as TMSB4X.

The interactions between integrin α5β1 of liver cancer cells and fibronectin of fibroblasts promote tumor growth and angiogenesis

Hepatocellular carcinoma (HCC) progression is closely related to pathological fibrosis, which involves heterotypic intercellular interactions (HIIs) between liver cancer cells and fibroblasts. Here, we studied them in a direct coculture model, and identified fibronectin from fibroblasts and integrin-α₅β₁ from liver cancer cells as the primary responsible molecules utilizing CRISPR/Cas9 gene-editing technology. Coculture led to the formation of 3D multilayer microstructures, and obvious fibronectin remodeling was caused by upregulated integrin-α₅β₁, which greatly promoted cell growth in 3D microstructures. Integrin-α₅ was more sensitive and specific than integrin-β₁ in this process. Subsequent mechanistic exploration revealed the activation of integrin-Src-FAK, AKT and ERK signaling pathways. Importantly, the growth-promoting effect of HIIs was verified in a xenograft tumor model, in which more blood vessels were observed in bigger tumors derived from the coculture group than that derived from monocultured groups. Hence, we conducted triculture by introducing human umbilical vein endothelial cells, which aligned to and differentiated along multilayer microstructures in an integrin-α₅β₁ dependent manner. Furthermore, fibronectin, integrin-α₅, and integrin-β₁ were upregulated in 52 HCC tumors, and fibronectin was related to microvascular invasion. Our findings identify fibronectin, integrin-α₅, and integrin-β₁ as tumor microenvironment-related targets and provide a basis for combination targeted therapeutic strategies for future HCC treatment.

A three-dimensional human adipocyte model of fatty acid-induced obesity

Obesity prevalence has reached pandemic proportions, leaving individuals at high risk for the development of diseases such as cancer and type 2 diabetes. In obesity, to accommodate excess lipid storage, adipocytes become hypertrophic, which is associated with an increased pro-inflammatory cytokine secretion and dysfunction of metabolic processes such as insulin signaling and lipolysis. Targeting adipocyte dysfunction is an important strategy to prevent the development of obesity-associated disease. However, it is unclear how accurately animal models reflect human biology, and the long-term culture of human hypertrophic adipocytes in an in vitro 2D monolayer is challenging due to the buoyant nature of adipocytes. Here we describe the development of a human 3D in vitro disease model that recapitulates hallmarks of obese adipocyte dysfunction. First, primary human adipose-derived mesenchymal stromal cells are embedded in hydrogel, and infiltrated into a thin cellulose scaffold. The thin microtissue profile allows for efficient assembly and image-based analysis. After adipocyte differentiation, the scaffold is stimulated with oleic or palmitic acid to mimic caloric overload. Using functional assays, we demonstrated that this treatment induced important obese adipocyte characteristics such as a larger lipid droplet size, increased basal lipolysis, insulin resistance and a change in macrophage gene expression through adipocyte-conditioned media. This 3D disease model mimics physiologically relevant hallmarks of obese adipocytes, to enable investigations into the mechanisms by which dysfunctional adipocytes contribute to disease.

Modeling the Role of Cancer-Associated Fibroblasts in Tumor Cell Invasion

Simple Summary

Accurate in vitro modeling of diseases is essential to making breakthrough and clinically relevant discoveries. Assays to examine the process of invasion—a classical hallmark of cancer—have evolved over the years to overcome shortfalls in their design and accommodate new knowledge in the field, such as the role of the tumor microenvironment (TME) in propagating this process. The goals of this review are two-fold: To walk through the tried-and-true plus novel and new invasion assays currently used in cancer research with a focus on those incorporating cancer-associated fibroblasts (CAFs), and to be a resource for researchers to find the correct invasion assays that suit their own unique needs and biological questions.

Abstract

The major cause of cancer-related deaths can be attributed to the metastatic spread of tumor cells—a dynamic and complex multi-step process beginning with tumor cells acquiring an invasive phenotype to allow them to travel through the blood and lymphatic vessels to ultimately seed at a secondary site. Over the years, various in vitro models have been used to characterize specific steps in the cascade to collectively begin providing a clearer picture of the puzzle of metastasis. With the discovery of the TME’s supporting role in activating tumor cell invasion and metastasis, these models have evolved in parallel to accommodate features of the TME and to observe its interactions with tumor cells. In particular, CAFs that reside in reactive tumor stroma have been shown to play a substantial pro-invasive role through their matrix-modifying functions; accordingly, this warranted further investigation with the development and use of invasion assays that could include these stromal cells. This review explores the growing toolbox of assays used to study tumor cell invasion, from the simple beginnings of a tumor cell and extracellular matrix set-up to the advent of models that aim to more closely recapitulate the interplay between tumor cells, CAFs and the extracellular matrix. These models will prove to be invaluable tools to help tease out the intricacies of tumor cell invasion.

Fundamental and Clinical Applications of Materials Based on Cancer-Associated Fibroblasts in Cancers

Cancer stromal cells play a role in promoting tumor relapse and therapeutic resistance. Therefore, the current treatment paradigms for cancers are usually insufficient to eradicate cancer cells, and anti-cancer therapeutic strategies targeting stromal cells have been developed. Cancer-associated fibroblasts (CAFs) are perpetually activated fibroblasts in the tumor stroma. CAFs are the most abundant and highly heterogeneous stromal cells, and they are critically involved in cancer occurrence and progression. These effects are due to their various roles in the remodeling of the extracellular matrix, maintenance of cancer stemness, modulation of tumor metabolism, and promotion of therapy resistance. Recently, biomaterials and nanomaterials based on CAFs have been increasingly developed to perform gene or protein expression analysis, three-dimensional (3D) co-cultivation, and targeted drug delivery in cancer treatment. In this review, we systematically summarize the current research to fully understand the relevant materials and their functional diversity in CAFs, and we highlight the potential clinical applications of CAFs-oriented biomaterials and nanomaterials in anti-cancer therapy.

Engineering strategies to capture the biological and biophysical tumor microenvironment in vitro

Despite decades of research and advancements in diagnostic and treatment modalities, cancer remains a major global healthcare challenge. This is due in part to a lack of model systems that allow investigating the mechanisms underlying tumor development, progression, and therapy resistance under relevant conditions in vitro. Tumor cell interactions with their surroundings influence all stages of tumorigenesis and are shaped by both biological and biophysical cues including cell-cell and cell-extracellular matrix (ECM) interactions, tissue architecture and mechanics, and mass transport. Engineered tumor models provide promising platforms to elucidate the individual and combined contributions of these cues to tumor malignancy under controlled and physiologically relevant conditions. This review will summarize current knowledge of the biological and biophysical microenvironmental cues that influence tumor development and progression, present examples of in vitro model systems that are presently used to study these interactions and highlight advancements in tumor engineering approaches to further improve these technologies.

Precision Medicine Gains Momentum: Novel 3D Models and Stem Cell-Based Approaches in Head and Neck Cancer

Despite the current progress in the development of new concepts of precision medicine for head and neck squamous cell carcinoma (HNSCC), in particular targeted therapies and immune checkpoint inhibition (CPI), overall survival rates have not improved during the last decades. This is, on the one hand, caused by the fact that a significant number of patients presents with late stage disease at the time of diagnosis, on the other hand HNSCC frequently develop therapeutic resistance. Distinct intratumoral and intertumoral heterogeneity is one of the strongest features in HNSCC and has hindered both the identification of specific biomarkers and the establishment of targeted therapies for this disease so far. To date, there is a paucity of reliable preclinical models, particularly those that can predict responses to immune CPI, as these models require an intact tumor microenvironment (TME). The "ideal" preclinical cancer model is supposed to take both the TME as well as tumor heterogeneity into account. Although HNSCC patients are frequently studied in clinical trials, there is a lack of reliable prognostic biomarkers allowing a better stratification of individuals who might benefit from new concepts of targeted or immunotherapeutic strategies. Emerging evidence indicates that cancer stem cells (CSCs) are highly tumorigenic. Through the process of stemness, epithelial cells acquire an invasive phenotype contributing to metastasis and recurrence. Specific markers for CSC such as CD133 and CD44 expression and ALDH activity help to identify CSC in HNSCC. For the majority of patients, allocation of treatment regimens is simply based on histological diagnosis and on tumor location and disease staging (clinical risk assessments) rather than on specific or individual tumor biology. Hence there is an urgent need for tools to stratify HNSCC patients and pave the way for personalized therapeutic options. This work reviews the current literature on novel approaches in implementing three-dimensional (3D) HNSCC in vitro and in vivo tumor models in the clinical daily routine. Stem-cell based assays will be particularly discussed. Those models are highly anticipated to serve as a preclinical prediction platform for the evaluation of stable biomarkers and for therapeutic efficacy testing.

A ceRNA-associated risk model predicts the poor prognosis for head and neck squamous cell carcinoma patients

Head and neck squamous cell carcinoma (HNSCC) is one of the most malignant cancers with poor prognosis worldwide. Emerging evidence indicates that competing endogenous RNAs (ceRNAs) are involved in various diseases, however, the regulatory mechanisms of ceRNAs underlying HNSCC remain unclear. In this study, we retrieved differentially expressed long non-coding RNAs (DElncRNAs), messenger RNAs (DEmRNAs) and microRANs (DEmiRNAs) from The Cancer Genome Atlas database and constructed a ceRNA-based risk model in HNSCC by integrated bioinformatics approaches. Functional enrichment analyses showed that DEmRNAs might be involved in extracellular matrix related biological processes, and protein–protein interaction network further selected out prognostic genes, including MYL1 and ACTN2. Importantly, co-expressed RNAs identified by weighted co-expression gene network analysis constructed the ceRNA networks. Moreover, AC114730.3, AC136375.3, LAT and RYR3 were highly correlated to overall survival of HNSCC by Kaplan–Meier method and univariate Cox regression analysis, which were subsequently implemented multivariate Cox regression analysis to build the risk model. Our study provides a deeper understanding of ceRNAs on the regulatory mechanisms, which will facilitate the expansion of the roles on the ceRNAs in the tumorigenesis, development and treatment of HNSCC.