Cell Adhesion and Matrix Stiffness: Coordinating Cancer Cell Invasion and Metastasis

Magnetic Resonance Elastography for Breast Cancer Diagnosis Through the Assessment of Tissue Biomechanical Properties

Background and Aim

Breast cancer and normal breast tissue exhibit different degrees of stiffness, indicating distinct biomechanical properties. Study results reveal that breast cancer tissue is several times stiffer than normal breast tissue. These variations can serve as indicative factors for imaging purposes. Depicting markers can significantly enhance the process of breast cancer diagnosis and treatment. This article provides a brief review of the biomechanical properties of breast cancer tissue, highlighting the role of the magnetic resonance elastography (MRE) technique in utilizing these properties for diagnosing breast cancer.

Methods

In breast MRE, low-frequency shear waves are employed to measure breast stiffness. This method not only offers a quantitative diagnosis but also generates an elastogram, determining the stiffness of each area through its colors.

Results

MRE represents a diagnostic technique with heightened sensitivity, based on depicting the viscoelasticity properties of breast tissue and describing tumors in terms of biomechanical properties. Combining tissue biomechanical properties, such as tissue stiffness, with contrast-enhanced breast Magnetic Resonance Imaging (MRI) leads to tumor diagnosis. The value of MRE in oncological imaging aims at the early detection of tumors and evaluating the prognosis of breast cancer.

Conclusion

Breast MRE can identify the reduction of interstitial pressure in tumors by detecting changes in tissue stiffness, making it an effective tool for monitoring treatment responses. This technique is safe, repeatable, and highly precise, significantly aiding in patient screening.

The unfolded protein response sensor PERK mediates mechanical stress-induced maturation of focal adhesion complexes in glioblastoma cells

Stiffening of the brain extracellular matrix (ECM) in glioblastoma promotes tumor progression. Previously, we discovered that protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) plays a role in glioblastoma stem cell (GSC) adaptation to matrix stiffness through PERK/FLNA-dependent F-actin remodeling. Here, we examined the involvement of PERK in detecting stiffness changes via focal adhesion complex (FAC) formation. Compared to control GSCs, PERK-deficient GSCs show decreased vinculin and tensin expression, while talin and integrin-β1 remain constant. Furthermore, vimentin was also reduced while tubulin increased, and a stiffness-dependent increase of the differentiation marker GFAP expression was absent in PERK-deficient GSCs. In conclusion, our study reveals a novel role for PERK in FAC formation during matrix stiffening, which is likely linked to its regulation of F-actin remodeling.

Remodeling of the extracellular matrix by serine proteases as a prerequisite for cancer initiation and progression

The extracellular matrix (ECM) serves as a physical scaffold for tissues that is composed of structural proteins such as laminins, collagens, proteoglycans and fibronectin, forming a three dimensional network, and a wide variety of other matrix proteins with ECM-remodeling and signaling functions. The activity of ECM-associated signaling proteins is tightly regulated. Thus, the ECM serves as a reservoir for water and growth regulatory signals. The ECM architecture is dynamically modulated by multiple serine proteases that process both structural and signaling proteins to regulate physiological processes such as organogenesis and tissue homeostasis but they also contribute to pathological events, especially cancer progression. Here, we review the current literature regarding the role of ECM remodeling by serine proteases (KLKs, uPA, furin, HtrAs, granzymes, matriptase, hepsin) in tumorigenesis.

In vitro regulation of collective cell migration: Understanding the role of physical and chemical microenvironments

Collective cell migration is the primary mode of cellular movement during embryonic morphogenesis, tissue repair and regeneration, and cancer invasion. Distinct from single-cell migration, collective cell migration involves complex intercellular signaling cascades and force transmission. Consequently, cell collectives exhibit intricate and diverse migration patterns under the influence of the microenvironment in vivo. Investigating the patterns and mechanisms of collective cell migration within complex environmental factors in vitro is essential for elucidating collective cell migration in vivo. This review elucidates the influence of physical and chemical factors in vitro microenvironment on the migration patterns and efficiency of cell collectives, thereby enhancing our comprehension of the phenomenon. Furthermore, we concisely present the effects of characteristic properties of common biomaterials on collective cell migration during tissue repair and regeneration, as well as the features and applications of tumor models of different dimensions (2D substrate or 3D substrate) in vitro. Finally, we highlight the challenges facing the research of collective cell migration behaviors in vitro microenvironment and propose that modulating collective cell migration may represent a potential strategy to promote tissue repair and regeneration and to control tumor invasion and metastasis.

Label-Free Single-Cell Cancer Classification from the Spatial Distribution of Adhesion Contact Kinetics

There is an increasing need for simple-to-use, noninvasive, and rapid tools to identify and separate various cell types or subtypes at the single-cell level with sufficient throughput. Often, the selection of cells based on their direct biological activity would be advantageous. These steps are critical in immune therapy, regenerative medicine, cancer diagnostics, and effective treatment. Today, live cell selection procedures incorporate some kind of biomolecular labeling or other invasive measures, which may impact cellular functionality or cause damage to the cells. In this study, we first introduce a highly accurate single-cell segmentation methodology by combining the high spatial resolution of a phase-contrast microscope with the adhesion kinetic recording capability of a resonant waveguide grating (RWG) biosensor. We present a classification workflow that incorporates the semiautomatic separation and classification of single cells from the measurement data captured by an RWG-based biosensor for adhesion kinetics data and a phase-contrast microscope for highly accurate spatial resolution. The methodology was tested with one healthy and six cancer cell types recorded with two functionalized coatings. The data set contains over 5000 single-cell samples for each surface and over 12,000 samples in total. We compare and evaluate the classification using these two types of surfaces (fibronectin and noncoated) with different segmentation strategies and measurement timespans applied to our classifiers. The overall classification performance reached nearly 95% with the best models showing that our proof-of-concept methodology could be adapted for real-life automatic diagnostics use cases. The label-free measurement technique has no impact on cellular functionality, directly measures cellular activity, and can be easily tuned to a specific application by varying the sensor coating. These features make it suitable for applications requiring further processing of selected cells.

Loss of the predicted cell adhesion molecule MPZL3 promotes EMT and chemoresistance in ovarian cancer

Myelin protein zero-like 3 (MPZL3) is an Immunoglobulin-containing transmembrane protein with predicted cell adhesion molecule function. Loss of 11q23, where the MPZL3 gene resides, is frequently observed in cancer, and MPZL3 copy number alterations are frequently detected in tumor specimens. Yet the role and consequences of altered MPZL3 expression have not been explored in tumor development and progression. We addressed this in ovarian cancer, where both MPZL3 amplification and deletions are observed in respective subsets of high-grade serous specimens. While high and low MPZL3 expressing populations were similarly observed in primary ovarian tumors from an independent patient cohort, metastatic omental tumors largely displayed decreased MPZL3 expression, suggesting that MPZL3 loss is associated with metastatic progression. MPZL3 knock-down leads to strong upregulation of vimentin and an EMT gene signature that is associated with poor patient outcomes. Moreover, MPZL3 is necessary for homotypic cancer cell adhesion, and decreasing MPZL3 expression enhances invasion and clearance of mesothelial cell monolayers. In addition, MPZL3 loss abrogated cell cycle progression and proliferation. This was associated with increased resistance to Cisplatin and Olaparib and reduced DNA damage and apoptosis in response to these agents. Enhanced Cisplatin resistance was further validated in vivo . These data demonstrate for the first time that MPZL3 acts as an adhesion molecule and that MPZL3 loss results in EMT, decreased proliferation, and drug resistance in ovarian cancer. Our study suggests that decreased MPZL3 expression is a phenotype of ovarian cancer tumor progression and metastasis and may contribute to treatment failure in advanced-stage patients.

Serum from Hypertensive Patients Induces Cancer-Supporting Phenotype of Vascular Endothelium In Vitro

BACKGROUND/OBJECTIVES

Large-scale epidemiological studies have established a bidirectional association between hypertension and cancer. However, the underlying mechanisms explaining this connection remain unclear. In our study, we investigated whether serum from patients with hypertension (HT) could enhance the aggressiveness of cancer cells in vitro through alterations in endothelial cell phenotype.

METHODS

Experiments were performed using EAhy926 endothelial cells and ovarian (SKOV-3), colorectal (SW480), pancreatic (PSN-1), breast (MCF-7), and lung (A549) cancer cell lines.

RESULTS

This study showed that conditioned medium (CM) produced by EAhy926 cells, when exposed to serum from patients with untreated hypertension (HT-CM), promotes the proliferation, migration, and invasion of every cancer cell line tested. In addition, endothelial cells subjected to HT serum promote the adhesion of all cancer cell types except PSN-1. An intensified transendothelial invasion of cancer cells was accompanied by decreased expression of junctional proteins (connexin 43, E-cadherin, occluding, desmoglein) in HT serum-treated endothelial cells. Quantitative analysis of the secretome of endothelial cells subjected to HT serum showed that they secrete increased amounts of CCL2, CXCL1, CXCL8, bFGF, HGF, IL-6, PAI-1, and TGF-β1. Moreover, cancer cells exposed to HT-CM display increased mRNA expression for several pro-cancerogenic agents, including CXCL8, tPA, and VEGF.

CONCLUSIONS

Our report shows that hypertension may potentiate cancer cell aggressiveness by modulating endothelial cell phenotype. Further tests with antihypertensive drugs are required to assess whether effective treatment of hypertension can mitigate its cancer-promoting potential.

Association of endometrial cancer risk with hypertension- an updated meta-analysis of observational studies

Endometrial cancer is one of the most common gynaecological cancers in the developed countries. The aim of this study was to determine the impact of hypertension on endometrial cancer risk. Databases: PubMed, Embase and the Cochrane Library were searched from January 2000 to June 2024. We used DerSimonian-Laird random-effects model for analysis. Risk estimates were extracted by two authors and summarized using meta-analytic methods. A total of 26 observational studies with 207,502 endometrial cancer cases were included in the study. Overall meta-analysis demonstrates significant association between hypertension and endometrial cancer risk (RR = 1.37, 95% CI: 1.27-1.47, p < 0.001). Subgroup analysis of the risk of endometrial cancer shows statistically significant higher risk in patients with BMI ≥ 30 kg/m2, diabetics, women who had their first menstrual period at the age of 11 years or earlier, and who had never given birth. Findings of this comprehensive review and meta-analysis indicate that hypertension is associated with higher overall risk of endometrial cancer.

Invasion/chemotaxis- and extravasation-chip models for breast cancer bone metastasis

Bone is one of the most frequently targeted organs in metastatic cancers including the breast. Breast cancer bone metastasis often results in devastating outcomes as limited treatment options are currently available. Therefore, innovative methods are needed to provide earlier detection and thus better treatment and prognosis. Here, we present a new approach to model bone-like microenvironments to detect invasion and extravasation of breast cancer cells using invasion/chemotaxis (IC-) and extravasation (EX-) chips, respectively. Our results show that the behaviors of MDA-MB-231 breast cancer cells on IC- and EX-chip models correlate with their in vivo metastatic potential. Our culture model constitutes cell lines representing osteoblasts, bone marrow stromal cells, and monocytes embedded in three-dimensional (3D) collagen I-based extracellular matrices of varying composition and stiffness. We show that collagen I offers a better bone-like environment for bone cells and matrix composition and stiffness regulate the invasion of breast cancer cells. Using in situ contactless rheological measurements under cell culture conditions, we show that the presence of cells increased the stiffness values of the matrices up to 1200 Pa when monitored for five days. This suggests that the cellular composition has a significant effect on regulating matrix mechanical properties, which in turn contribute to the invasiveness. The platforms we present here enable the investigation of the underlying molecular mechanisms in breast cancer bone metastasis and provide the groundwork of developing preclinical tools for the prediction of bone metastasis risk.

Increased matrix stiffness in pituitary neuroendocrine tumors invading the cavernous sinus is activated by TAFs: focus on the mechanical signatures

PURPOSE

Pituitary neuroendocrine tumors (PitNETs) with invasion of the cavernous sinus (CS) are particularly challenging to treat. Tumor associated fibroblasts (TAFs) are recognized for their pivotal role in reprogramming extracellular matrix (ECM). Herein, we aimed to explore the potential involvement of TAFs in ECM reprogramming and elucidate the underlying mechanism involved.

METHODS

We applied dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to measure tumor vessel permeability and applied atomic force microscopy (AFM) to measure the matrix stiffness of PitNETs located in both CS and sella turcica (ST). Western blotting, immunofluorescence, immunohistochemistry, and quantitative RT-PCR were utilized to analyze the ECM components. Proteomic biochemical analysis was utilized to uncover potential mechanisms governing ECM dynamics.

RESULTS

We found that PitNETs in the CS were stiffer than those in the ST. Increased ECM stiffness within the CS facilitated the acquisition of stem-like properties, enhanced proliferation, and induced epithelial-to-mesenchymal transition (EMT) of GH3 cells. Furthermore, the expression levels of lysyl oxidase (LOX), matrix metallopeptidase 2 (MMP2) and MMP9 in pituitary adenoma cells increased in the stiffer matrix. Proteomic analysis suggested TAFs were activated in the CS area and contributed enhanced matrix stiffness by secreting Col-1 and Col-3. Furthermore, mTOR pathway was activated under higher matrix stiffness and the migration and invasion of GH3 cells be repressed by mTOR inhibitor.

CONCLUSION

These findings demonstrated that activated TAFs contributed to stiffer matrix and increased ECM stiffness stimulating mTOR pathway in pituitary tumor cells. Our study indicated that mTOR inhibitor was a promising treatment strategy from the standpoint of PitNET biomechanical properties.

Exploring the potential role of palladin in modulating human CAF/ECM functional units

Fibroblasts, crucial for maintaining tissue homeostasis, significantly shape the tumor microenvironment (TME). In pancreatic cancer, a highly aggressive malignancy, cancer-associated fibroblast (CAF)/extracellular matrix (ECM) units dominate the TME, influencing tumor initiation, progression, and treatment responses. Palladin, an actin-associated protein, is vital for fibroblast structural integrity and activation, playing a key role in CAF/ECM functionality. Palladin interacts with cytoskeletal proteins such as alpha-actinin (α-Act) and can therefore regulate other proteins like syndecans, modulating cytoskeletal features, cell adhesion, integrin recycling, and signaling. In this review, we propose that targeting the palladin/α-Act/syndecan interaction network could modulate CAF/ECM units, potentially shifting the TME from a tumor-promoting to a tumor-suppressive state. In silico data and reported studies to suggest that stabilizing palladin-α-Act interactions, via excess palladin, influences syndecan functions; potentially modulating integrin endocytosis via syndecan engagement with protein kinase C alpha as opposed to syndecan binding to α-Act. This mechanism can then affect the distribution of active α5β1-integrin between the plasma membrane and known intracellular vesicular compartments, thereby influencing the tumor-suppressive versus tumor-promoting functions of CAF/ECM units. Understanding these interactions offers likely future therapeutic avenues for stroma normalization in pancreatic and other cancers, aiming to inhibit tumor progression and improve future treatment outcomes.

Bioactive Microgels with Tunable Microenvironment as a 3D Platform to Guide the Complex Physiology of Hepatocellular Carcinoma Spheroids

Miniaturized three-dimensional tissue models, such as spheroids, have become a highly useful and efficient platform to investigate tumor physiology and explore the effect of chemotherapeutic efficacy over traditional two-dimensional monolayer culture, since they can provide more in-depth analysis, especially in regards to intercellular interactions and diffusion. The development of most tumor spheroids relies on the high proliferative capacity and self-aggregation behavior of tumor cells. However, it often disregards the effect of microenvironmental factors mediated by extracellular matrix, which are indispensable components of tissue structure. In this study, hepatocellular carcinoma (HCC) cells are encapsulated in bioactive microgels consisting of gelatin and hyaluronic acid designed to emulate tumor microenvironment in order to induce hepatic tumor spheroid formation. Two different subtypes of HCC's, HepG2 and Hep3B cell lines, are explored. The physicomechanical and biochemical properties of the microgels, controlled by changing the crosslinking density and polymer composition, are clearly shown to have substantial influence over the formation and spheroid formation. Moreover, the spheroids made from different cells and microgel properties display highly variable chemoresistance effects, further highlighting the importance of microenvironmental factors guiding tumor spheroid physiology.

Cooperation between SIX1 and DHX9 transcriptionally regulates integrin-focal adhesion signaling mediated metastasis and sunitinib resistance in KIRC

High invasive capacity and acquired tyrosine kinase inhibitors (TKI) resistance of kidney renal clear cell carcinoma (KIRC) cells remain obstacles to prolonging the survival time of patients with advanced KIRC. In the present study, we reported that sine oculis homeobox 1 (SIX1) was upregulated in sunitinib-resistant KIRC cells and metastatic KIRC tissues. Subsequently, we found that SIX1 mediated metastasis and sunitinib resistance via Focal adhesion (FA) signaling, and knockdown of SIX1 enhanced the antitumor efficiency of sunitinib in KIRC. Mechanistically, Integrin subunit beta 1 (ITGB1), an upstream gene of FA signaling, was a direct transcriptional target of SIX1. In addition, we showed that DExH-box helicase 9 (DHX9) was an important mediator for SIX1-induced ITGB1 transcription, and silencing the subunits of SIX1/DHX9 complex significantly reduced transcription of ITGB1. Downregulation of SIX1 attenuated nuclear translocation of DHX9 and abrogated the binding of DHX9 to ITGB1 promoter. Collectively, our results unveiled a new signal axis SIX1/ITGB1/FAK in KIRC and identified a novel therapeutic strategy for metastatic KIRC patients.

Emerin deficiency drives MCF7 cells to an invasive phenotype

During metastasis, cancer cells traverse the vasculature by squeezing through very small gaps in the endothelium. Thus, nuclei in metastatic cancer cells must become more malleable to move through these gaps. Our lab showed invasive breast cancer cells have 50% less emerin protein resulting in smaller, misshapen nuclei, and higher metastasis rates than non-cancerous controls. Thus, emerin deficiency was predicted to cause increased nuclear compliance, cell migration, and metastasis. We tested this hypothesis by downregulating emerin in noninvasive MCF7 cells and found emerin knockdown causes smaller, dysmorphic nuclei, resulting in increased impeded cell migration. Emerin reduction in invasive breast cancer cells showed similar results. Supporting the clinical relevance of emerin reduction in cancer progression, our analysis of 192 breast cancer patient samples showed emerin expression inversely correlates with cancer invasiveness. We conclude emerin loss is an important driver of invasive transformation and has utility as a biomarker for tumor progression.

Emerin deficiency drives MCF7 cells to an invasive phenotype

During metastasis, cancer cells traverse the vasculature by squeezing through very small gaps in the endothelium. Thus, nuclei in metastatic cancer cells must become more malleable to move through these gaps. Our lab showed invasive breast cancer cells have 50% less emerin protein resulting in smaller, misshapen nuclei, and higher metastasis rates than non-cancerous controls. Thus, emerin deficiency was predicted to cause increased nuclear compliance, cell migration, and metastasis. We tested this hypothesis by downregulating emerin in noninvasive MCF7 cells and found emerin knockdown causes smaller, dysmorphic nuclei, resulting in increased impeded cell migration. Emerin reduction in invasive breast cancer cells showed similar results. Supporting the clinical relevance of emerin reduction in cancer progression, our analysis of 192 breast cancer patient samples showed emerin expression inversely correlates with cancer invasiveness. We conclude emerin loss is an important driver of invasive transformation and has utility as a biomarker for tumor progression.

The role of cancer-associated fibroblasts in the invasion and metastasis of colorectal cancer

Colorectal cancer (CRC) is the third most common cancer and has ranked the third leading cause in cancerassociated death globally. Metastasis is the leading cause of death in colorectal cancer patients. The role of tumor microenvironment (TME) in colorectal cancer metastasis has received increasing attention. As the most abundant cell type in the TME of solid tumors, cancer-associated fibroblasts (CAFs) have been demonstrated to have multiple functions in advancing tumor growth and metastasis. They can remodel the extracellular matrix (ECM) architecture, promote epithelial-mesenchymal transition (EMT), and interact with cancer cells or other stromal cells by secreting growth factors, cytokines, chemokines, and exosomes, facilitating tumor cell invasion into TME and contributing to distant metastasis. This article aims to analyze the sources and heterogeneity of CAFs in CRC, as well as their role in invasion and metastasis, in order to provide new insights into the metastasis mechanism of CRC and its clinical applications.

Sensitivity of magnetic resonance elastography to extracellular matrix and cell motility in human prostate cancer cell line-derived xenograft models

Prostate cancer (PCa) is a significant health problem in the male population of the Western world. Magnetic resonance elastography (MRE), an emerging medical imaging technique sensitive to mechanical properties of biological tissues, detects PCa based on abnormally high stiffness and viscosity values. Yet, the origin of these changes in tissue properties and how they correlate with histopathological markers and tumor aggressiveness are largely unknown, hindering the use of tumor biomechanical properties for establishing a noninvasive PCa staging system. To infer the contributions of extracellular matrix (ECM) components and cell motility, we investigated fresh tissue specimens from two PCa xenograft mouse models, PC3 and LNCaP, using magnetic resonance elastography (MRE), diffusion-weighted imaging (DWI), quantitative histology, and nuclear shape analysis. Increased tumor stiffness and impaired water diffusion were observed to be associated with collagen and elastin accumulation and decreased cell motility. Overall, LNCaP, while more representative of clinical PCa than PC3, accumulated fewer ECM components, induced less restriction of water diffusion, and exhibited increased cell motility, resulting in overall softer and less viscous properties. Taken together, our results suggest that prostate tumor stiffness increases with ECM accumulation and cell adhesion - characteristics that influence critical biological processes of cancer development. MRE paired with DWI provides a powerful set of imaging markers that can potentially predict prostate tumor development from benign masses to aggressive malignancies in patients. STATEMENT OF SIGNIFICANCE: Xenograft models of human prostate tumor cell lines, allowing correlation of microstructure-sensitive biophysical imaging parameters with quantitative histological methods, can be investigated to identify hallmarks of cancer.

Combined effects of matrix stiffness and obesity-associated signaling directs progressive phenotype in PANC-1 pancreatic cancer cells in vitro

Obesity is a leading risk factor of pancreatic ductal adenocarcinoma (PDAC) that contributes to poor disease prognosis and outcomes. Retrospective studies have identified this link, but interactions surrounding obesity and PDAC are still unclear. Research has shifted to contributions of fibrosis (desmoplasia) on malignancy, which involves increased deposition of collagens and other extracellular matrix (ECM) molecules and increased ECM crosslinking, all of which contribute to increased tissue stiffening. However, fibrotic stiffening is underrepresented as a model feature in current PDAC models. Fibrosis is shared between PDAC and obesity, and can be leveraged for in vitro model design, as current animal obesity models of PDAC are limited in their ability to isolate individual components of fibrosis to study cell behavior. In the current study, methacrylated type I collagen (PhotoCol®) was photo-crosslinked to pathological stiffness levels to recapitulate fibrotic ECM stiffening. PANC-1 cells were encapsulated within PhotoCol®, and the tumor-tissue constructs were prepared to represent normal (healthy) (~600 Pa) and pathological (~2000 Pa) tissues. Separately, human mesenchymal stem cells were differentiated into adipocytes representing lean (2D differentiation) and obese fat tissue (3D collagen matrix differentiation), and conditioned media was applied to PANC-1 tumor-tissue constructs. Conditioned media from obese adipocytes showed increased vimentin expression, a hallmark of invasiveness and progression, that was not seen after exposure to media from lean adipocytes or control media. Characterization of the obese adipocyte secretome suggested that some PANC-1 differences may arise from increased interleukin-8 and -10 compared to lean adipocytes. Additionally, high matrix stiffness associated induced an amoeboid morphology in PANC-1 cells that was not present at low stiffness. Amoeboid morphology is an accessory to epithelial-to-mesenchymal transition and is used to navigate complex ECM environments. This plasticity has greater implications for treatment efficacy of metastatic cancers. Overall, this work 1) highlights the importance of investigating PDAC-obesity interactions to study the effects on disease progression and persistence, 2) establishes PhotoCol® as a matrix material that can be leveraged to study amoeboid morphology and invasion in PDAC, and 3) emphasizes the importance of integrating both biophysical and biochemical interactions associated within both pathologies for in vitro PDAC models.

Cellular elasticity in cancer: a review of altered biomechanical features

A large number of studies have shown that changes in biomechanical characteristics are an important indicator of tumor transformation in normal cells. Elastic deformation is one of the more studied biomechanical features of tumor cells, which plays an important role in tumourigenesis and development. Altered cell elasticity often brings many indications. This manuscript reviews the effects of altered cellular elasticity on cell characteristics, including adhesion viscosity, migration, proliferation, and differentiation elasticity and stiffness. Also, the physical factors that may affect cell elasticity, such as temperature, cell height, cell-viscosity, and aging, are summarized. Then, the effects of cell-matrix, cytoskeleton, in vitro culture medium, and cell-substrate with different three-dimensional structures on cell elasticity during cell tumorigenesis are outlined. Importantly, we summarize the current signaling pathways that may affect cellular elasticity, as well as tests for cellular elastic deformation. Finally, we summarize current hybrid materials: polymer-polymer, protein-protein, and protein-polymer hybrids, also, nano-delivery strategies that target cellular resilience and cases that are at least in clinical phase 1 trials. Overall, the behavior of cancer cell elasticity is modulated by biological, chemical, and physical changes, which in turn have the potential to alter cellular elasticity, and this may be an encouraging prediction for the future discovery of cancer therapies.

Differential modulation of cell morphology, migration, and Neuropilin-1 expression in cancer and non-cancer cell lines by substrate stiffness

Physical changes in the tumor microenvironment, such as increased stiffness, regulate cancer hallmarks and play an essential role in gene expression, cell morphology, migration, and malignancy. However, the response of cancer cells to stiffness is not homogeneous and varies depending on the cell type and its mechanosensitivity. In this study, we investigated the differential responses of cervical (HeLa) and prostate (PC-3) cancer cell lines, as well as non-tumoral cell lines (HEK293 and HPrEC), to stiffness using polyacrylamide hydrogels mimicking normal and tumoral tissues. We analyzed cell morphology, migration, and the expression of neuropilin 1 (NRP1), a receptor involved in angiogenesis, cell migration, and extracellular matrix remodeling, known to be associated with cancer progression and poor prognosis. Our findings reveal that NRP1 expression increases on substrates mimicking the high stiffness characteristic of tumoral tissue in the non-tumoral cell lines HPrEC and HEK293. Conversely, in tumoral PC-3 cells, stiffness resembling normal prostate tissue induces an earlier and more sustained expression of NRP1. Furthermore, we observed that stiffness influences cell spreading, pseudopodia formation, and the mode of cell protrusion during migration. Soft substrates predominantly trigger bleb cell protrusion, while pseudopodia protrusions increase on substrates mimicking normal and tumor-like stiffnesses in HPrEC cells compared to PC-3 cells. Stiffer substrates also enhance the percentage of migratory cells, as well as their velocity and total displacement, in both non-tumoral and tumoral prostate cells. However, they only improve the persistence of migration in tumoral PC-3 cells. Moreover, we found that NRP1 co-localizes with actin, and its suppression impairs tumoral PC-3 spreading while decreasing pseudopodia protrusion mode. Our results suggest that the modulation of NRP1 expression by the stiffness can be a feedback loop to promote malignancy in non-tumoral and cancer cells, contingent upon the mechanosensitivity of the cells.

Biological evaluation of sulfonate and sulfate analogues of lithocholic acid: A bioisosterism-guided approach towards the discovery of potential sialyltransferase inhibitors for antimetastatic study

The naturally occurring bile acid lithocholic acid (LCA) has been a crucial core structure for many non-sugar-containing sialyltranferase (ST) inhibitors documented in literature. With the aim of elucidating the impact of the terminal carboxyl acid substituent of LCA on its ST inhibition, in this present study, we report the (bio)isosteric replacement-based design and synthesis of sulfonate and sulfate analogues of LCA. Among these compounds, the sulfate analogue SPP-002 was found to selectively inhibit N-glycan sialylation by at least an order of magnitude, indicating a substantial improvement in both potency and selectivity when compared to the unmodified parent bile acid. Molecular docking analysis supported the stronger binding of the synthetic analogue in the enzyme active site. Treatment with SPP-002 also hampered the migration, adhesion, and invasion of MDA-MB-231 cells in vitro by suppressing the expression of signaling proteins involved in the cancer metastasis-associated integrin/FAK/paxillin pathway. In totality, these findings offer not only a novel structural scaffold but also valuable insights for the future development of more potent and selective ST inhibitors with potential therapeutic effects against tumor cancer metastasis.

Cell volume expansion and local contractility drive collective invasion of the basement membrane in breast cancer

Breast cancer becomes invasive when carcinoma cells invade through the basement membrane (BM)-a nanoporous layer of matrix that physically separates the primary tumour from the stroma. Single cells can invade through nanoporous three-dimensional matrices due to protease-mediated degradation or force-mediated widening of pores via invadopodial protrusions. However, how multiple cells collectively invade through the physiological BM, as they do during breast cancer progression, remains unclear. Here we developed a three-dimensional in vitro model of collective invasion of the BM during breast cancer. We show that cells utilize both proteases and forces-but not invadopodia-to breach the BM. Forces are generated from a combination of global cell volume expansion, which stretches the BM, and local contractile forces that act in the plane of the BM to breach it, allowing invasion. These results uncover a mechanism by which cells collectively interact to overcome a critical barrier to metastasis.

Dysregulated microRNAs and long non-coding RNAs associated with extracellular matrix stiffness

Extracellular matrix (ECM) stiffness regulates development and homeostasis in vivo and affects both physiological and pathological processes. A variety of studies have demonstrated that mRNAs, such as Piezo1, integrin β1, and Yes-associated protein (YAP)/tafazzin (TAZ), can sense the mechanical signals induced by ECM stiffness and transmit them from the extracellular space into the cytoplasm. Non-coding RNAs (ncRNAs), such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), have been reported to play important roles in various cellular processes. Therefore, the interactions between ncRNAs and ECM stiffness, as well as the underlying molecular mechanisms, have become intriguing. In this review, we summarize recent findings on miRNAs and lncRNAs that interact with ECM stiffness. Several miRNAs and lncRNAs are involved in the progression of liver cancer, breast cancer, osteosarcoma, and cardiovascular diseases under the regulation of ECM stiffness. Through these ncRNAs, cellular behaviors including cell differentiation, proliferation, adhesion, migration, invasion, and epithelial-mesenchymal transition (EMT) are affected by ECM stiffness. We also integrate the ncRNA signaling pathways associated with ECM stiffness, in which typical signaling pathways like integrin β1/TGFβ1, phosphatidylinositol-3 kinase (PI3K)/AKT, and EMT are involved. Although our understanding of the relationships between ncRNAs and ECM stiffness is still limited, further investigations may provide new insights for disease treatment. ECM-associated ncRNAs may serve as disease biomarkers or be targeted by drugs.

Matrix confinement modulates 3D spheroid sorting and burst-like collective migration

While it is known that cells with differential adhesion tend to segregate and preferentially sort, the physical forces governing sorting and invasion in heterogeneous tumors remain poorly understood. To investigate this, we tune matrix confinement, mimicking changes in the stiffness and confinement of the tumor microenvironment, to explore how physical confinement influences individual and collective cell migration in 3D spheroids. High levels of confinement lead to cell sorting while reducing matrix confinement triggers the collective fluidization of cell motion. Cell sorting, which depends on cell-cell adhesion, is crucial to this phenomenon. Burst-like migration does not occur for spheroids that have not undergone sorting, regardless of the degree of matrix confinement. Using computational Self-Propelled Voronoi modeling, we show that spheroid sorting and invasion into the matrix depend on the balance between cell-generated forces and matrix resistance. The findings support a model where matrix confinement modulates 3D spheroid sorting and unjamming in an adhesion-dependent manner, providing insights into the mechanisms of cell sorting and migration in the primary tumor and toward distant metastatic sites. STATEMENT OF SIGNIFICANCE: The mechanical properties of the tumor microenvironment significantly influence cancer cell migration within the primary tumor, yet how these properties affect intercellular interactions in heterogeneous tumors is not well understood. By utilizing calcium and calcium chelators, we dynamically alter collagen-alginate hydrogel stiffness and investigate tumor cell behavior within co-culture spheroids in response to varying degrees of matrix confinement. High confinement is found to trigger cell sorting while reducing confinement for sorted spheroids facilitates collective cell invasion. Notably, without prior sorting, spheroids do not exhibit burst-like migration, regardless of confinement levels. This work establishes that matrix confinement and intercellular adhesion regulate 3D spheroid dynamics, offering insights into cellular organization and migration within the primary tumor.

The prognostic and potentially immunomodulatory role of cartilage oligomeric matrix protein in patients with gastric and esophageal adenocarcinoma

BACKGROUND

Cartilage oligomeric matrix protein (COMP) is a novel regulator of the tumor microenvironment. Studies in colon cancer and pancreatobiliary adenocarcinoma have revealed COMP expression to be associated with decreased infiltration of immune cells in the tumor microenvironment. Herein, the expression of COMP was investigated in gastric and esophageal adenocarcinoma with particular reference to its the relationship with the immune microenvironment.

METHODS

COMP expression was evaluated in tissue microarrays representing primary tumors from 159 patients with chemo- and radiotherapy naïve esophageal and gastric adenocarcinoma and 67 matched samples of lymph node metastases using immunohistochemistry. Additionally, collagen fibers were stained with Sirius Red and evaluated with the FIJI macro TWOMBLI algorithm.

RESULTS

The expression of COMP in cancer cells in the entire cohort was associated with shorter overall survival (OS) (p = 0.013) and recurrence-free survival (RFS) (p = 0.029), while COMP expression in the stroma was correlated with shorter RFS (p = 0.042). Similar correlations were found for patients with gastric adenocarcinoma, whereas COMP expression was not prognostic in esophageal adenocarcinoma. Further, in the entire cohort, the expression of COMP in the stroma was correlated with exclusion of different populations of immune cells (CD8+, CD3+, FoxP3+, CD20+) from the tumor microenvironment. Finally, higher density and alignment of collagen fibers were correlated with the expression of COMP in the stroma.

CONCLUSIONS

Expression of COMP in gastric and esophageal adenocarcinoma was correlated with shorter OS and RFS. A reduced number of immune cells infiltrated the tumor microenvironment when COMP expression was detected. This phenomenon could be attributed to the denser collagen deposits, a hallmark of tumor fibrosis observed in COMP-expressing tumors.

Redox signaling-mediated tumor extracellular matrix remodeling: pleiotropic regulatory mechanisms

BACKGROUND

The extracellular matrix (ECM), a fundamental constituent of all tissues and organs, is crucial for shaping the tumor microenvironment. Dysregulation of ECM remodeling has been closely linked to tumor initiation and progression, where specific signaling pathways, including redox signaling, play essential roles. Reactive oxygen species (ROS) are risk factors for carcinogenesis whose excess can facilitate the oxidative damage of biomacromolecules, such as DNA and proteins. Emerging evidence suggests that redox effects can aid the modification, stimulation, and degradation of ECM, thus affecting ECM remodeling. These alterations in both the density and components of the ECM subsequently act as critical drivers for tumorigenesis. In this review, we provide an overview of the functions and primary traits of the ECM, and it delves into our current understanding of how redox reactions participate in ECM remodeling during cancer progression. We also discuss the opportunities and challenges presented by clinical strategies targeting redox-controlled ECM remodeling to overcome cancer.

CONCLUSIONS

The redox-mediated ECM remodeling contributes importantly to tumor survival, progression, metastasis, and poor prognosis. A comprehensive investigation of the concrete mechanism of redox-mediated tumor ECM remodeling and the combination usage of redox-targeted drugs with existing treatment means may reveal new therapeutic strategy for future antitumor therapies.

Mechanical properties of human tumour tissues and their implications for cancer development

The mechanical properties of cells and tissues help determine their architecture, composition and function. Alterations to these properties are associated with many diseases, including cancer. Tensional, compressive, adhesive, elastic and viscous properties of individual cells and multicellular tissues are mostly regulated by reorganization of the actomyosin and microtubule cytoskeletons and extracellular glycocalyx, which in turn drive many pathophysiological processes, including cancer progression. This Review provides an in-depth collection of quantitative data on diverse mechanical properties of living human cancer cells and tissues. Additionally, the implications of mechanical property changes for cancer development are discussed. An increased knowledge of the mechanical properties of the tumour microenvironment, as collected using biomechanical approaches capable of multi-timescale and multiparametric analyses, will provide a better understanding of the complex mechanical determinants of cancer organization and progression. This information can lead to a further understanding of resistance mechanisms to chemotherapies and immunotherapies and the metastatic cascade.

The RAGE Axis: A Relevant Inflammatory Hub in Human Diseases

In 1992, a transcendental report suggested that the receptor of advanced glycation end-products (RAGE) functions as a cell surface receptor for a wide and diverse group of compounds, commonly referred to as advanced glycation end-products (AGEs), resulting from the non-enzymatic glycation of lipids and proteins in response to hyperglycemia. The interaction of these compounds with RAGE represents an essential element in triggering the cellular response to proteins or lipids that become glycated. Although initially demonstrated for diabetes complications, a growing body of evidence clearly supports RAGE's role in human diseases. Moreover, the recognizing capacities of this receptor have been extended to a plethora of structurally diverse ligands. As a result, it has been acknowledged as a pattern recognition receptor (PRR) and functionally categorized as the RAGE axis. The ligation to RAGE leads the initiation of a complex signaling cascade and thus triggering crucial cellular events in the pathophysiology of many human diseases. In the present review, we intend to summarize basic features of the RAGE axis biology as well as its contribution to some relevant human diseases such as metabolic diseases, neurodegenerative, cardiovascular, autoimmune, and chronic airways diseases, and cancer as a result of exposure to AGEs, as well as many other ligands.

Knockdown of ribosome RNA processing protein 15 suppresses migration of hepatocellular carcinoma through inhibiting PATZ1-associated LAMC2/FAK pathway

BACKGROUND

Ribosomal RNA processing protein 15 (RRP15) has been found to regulate the progression of hepatocellular carcinoma (HCC). Nevertheless, the extent to which it contributes to the spread of HCC cells remains uncertain. Thus, the objective of this research was to assess the biological function of RRP15 in the migration of HCC.

METHODS

The expression of RRP15 in HCC tissue microarray (TMA), tumor tissues and cell lines were determined. In vitro, the effects of RRP15 knockdown on the migration, invasion and adhesion ability of HCC cells were assessed by wound healing assay, transwell and adhesion assay, respectively. The effect of RRP15 knockdown on HCC migration was also evaluated in vivo in a mouse model.

RESULTS

Bioinformatics analysis showed that high expression of RRP15 was significantly associated with low survival rate of HCC. The expression level of RRP15 was strikingly upregulated in HCC tissues and cell lines compared with the corresponding controls, and TMA data also indicated that RRP15 was a pivotal prognostic factor for HCC. RRP15 knockdown in HCC cells reduced epithelial-to-mesenchymal transition (EMT) and inhibited migration in vitro and in vivo, independent of P53 expression. Mechanistically, blockade of RRP15 reduced the protein level of the transcription factor POZ/BTB and AT hook containing zinc finger 1 (PATZ1), resulting in decreased expression of the downstream genes encoding laminin 5 subunits, LAMC2 and LAMB3, eventually suppressing the integrin β4 (ITGB4)/focal adhesion kinase (FAK)/nuclear factor κB kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway.

CONCLUSIONS

RRP15 promotes HCC migration by activating the LAMC2/ITGB4/FAK pathway, providing a new target for future HCC treatment.

Toward innovative approaches for exploring the mechanically regulated tumor-immune microenvironment

Within the complex tumor microenvironment, cells experience mechanical cues-such as extracellular matrix stiffening and elevation of solid stress, interstitial fluid pressure, and fluid shear stress-that significantly impact cancer cell behavior and immune responses. Recognizing the significance of these mechanical cues not only sheds light on cancer progression but also holds promise for identifying potential biomarkers that would predict therapeutic outcomes. However, standardizing methods for studying how mechanical cues affect tumor progression is challenging. This challenge stems from the limitations of traditional in vitro cell culture systems, which fail to encompass the critical contextual cues present in vivo. To address this, 3D tumor spheroids have been established as a preferred model, more closely mimicking cancer progression, but they usually lack reproduction of the mechanical microenvironment encountered in actual solid tumors. Here, we review the role of mechanical forces in modulating tumor- and immune-cell responses and discuss how grasping the importance of these mechanical cues could revolutionize in vitro tumor tissue engineering. The creation of more physiologically relevant environments that better replicate in vivo conditions will eventually increase the efficacy of currently available treatments, including immunotherapies.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

Validation and identification of anoikis-related lncRNA signatures for improving prognosis in clear cell renal cell carcinoma

BACKGROUND

Clear cell carcinoma (ccRCC) usually has a high metastasis rate and high mortality rate. To enable precise risk stratification, there is a need for novel biomarkers. As one form of apoptosis, anoikis results from the disruption of cell-cell connection or cell-ECM attachment. However, the impact of anoikis-related lncRNAs on ccRCC has not yet received adequate attention.

METHODS

The study utilized univariate Cox regression analysis in order to identify the overall survival (OS) associated anoikis-related lncRNAs (ARLs), followed by the LASSO algorithm for selection. On this basis, a risk model was subsequently established using five anoikis-related lncRNAs. To dig the inner molecular mechanism, KEGG, GO, and GSVA analyses were conducted. Additionally, the immune infiltration landscape was estimated using the ESTIMATE, CIBERSORT, and ssGSEA algorithms.

RESULTS

The study constructed a novel risk model based on five ARLs (AC092611.2, AC027601.2, AC103809.1, AL133215.2, and AL162586.1). Patients categorized as low-risk exhibited significantly better OS. Notably, the study observed marked different immune infiltration landscapes and drug sensitivity by risk stratification. Additionally, the study preliminarily explored potential signal pathways associated with risk stratification.

CONCLUSION

The study exhibited the crucial role of ARLs in the carcinogenesis of ccRCC, potentially through differential immune infiltration. Furthermore, the established risk model could serve as a valuable stratification factor for predicting OS prognosis.

Matrix confinement modulates 3D spheroid sorting and burst-like collective migration

While it is known that cells with differential adhesion tend to segregate and preferentially sort, the physical forces governing sorting and invasion in heterogeneous tumors remain poorly understood. To investigate this, we tune matrix confinement, mimicking changes in the stiffness and confinement of the tumor microenvironment, to explore how physical confinement influences individual and collective cell migration in 3D spheroids. High levels of confinement lead to cell sorting while reducing matrix confinement triggers the collective fluidization of cell motion. Cell sorting, which depends on cell-cell adhesion, is crucial to this phenomenon. Burst-like migration does not occur for spheroids that have not undergone sorting, regardless of the degree of matrix confinement. Using computational Self-Propelled Voronoi modeling, we show that spheroid sorting and invasion into the matrix depend on the balance between cell-generated forces and matrix resistance. The findings support a model where matrix confinement modulates 3D spheroid sorting and unjamming in an adhesion-dependent manner, providing insights into the mechanisms of cell sorting and migration in the primary tumor and toward distant metastatic sites.

Further structural optimization and SAR study of sungsanpin derivatives as cell-invasion inhibitors

Metastasis is one of the major causes of death in patients with cancer, and cell invasion plays a fundamental part in this process. Because of the absence of efficacious treatments, caring for these patients is challenging. Recently, we optimized the structure of the naturally occurring lasso peptide sungsanpin. We identified two peptides, octapeptide S3 and cyclic peptide S4, which inhibited invasion into A549 cells effectively. We undertook an alanine scan of S3 to explore the structure-activity relationship. The linear octapeptide S3-4 and cyclic peptide S4-1 exhibited improved inhibition of invasion into A549 cells. We modified S3-4 to obtain S3-4K, which displayed much higher inhibitory activity against invasion into A549 cells than S3-4. Of all peptides tested, S4-1 upregulated significantly mRNA of tissue inhibitor matrix metalloproteinase TIMP-1 and TIMP-2.

GALNT12 suppresses the bone-specific prostate cancer metastasis by activating BMP pathway via the O-glycosylation of BMPR1A

Bone metastasis caused the majority death of prostate cancer (PCa) but the mechanism remains poorly understood. In this present study, we show that polypeptide N-acetylgalactosaminyltransferase 12 (GALNT12) suppresses bone-specific metastasis of PCa. GALNT12 suppresses proliferation, migration, invasion and cell division ability of PCa cells by activating the BMP pathway. Mechanistic investigations showed that GALNT12 augments the O-glycosylation of BMPR1A then actives the BMP pathway. Activated BMP signaling inhibits the expression of integrin αVβ3 to reduce the bone-specific seeding of PCa cells. Furthermore, activated BMP signaling remolds the immune microenvironment by suppressing the STAT3 pathway. Our results of this study illustrate the role and mechanism of GALNT12 in the process of bone metastasis of PCa and identify GALNT12 as a potential therapeutic target for metastatic PCa.

Hypoxia inducible factor-1ɑ as a potential therapeutic target for osteosarcoma metastasis

Osteosarcoma (OS) is a malignant tumor originating from mesenchymal tissue. Pulmonary metastasis is usually present upon initial diagnosis, and metastasis is the primary factor affecting the poor prognosis of patients with OS. Current research shows that the ability to regulate the cellular microenvironment is essential for preventing the distant metastasis of OS, and anoxic microenvironments are important features of solid tumors. During hypoxia, hypoxia-inducible factor-1α (HIF-1α) expression levels and stability increase. Increased HIF-1α promotes tumor vascular remodeling, epithelial-mesenchymal transformation (EMT), and OS cells invasiveness; this leads to distant metastasis of OS cells. HIF-1α plays an essential role in the mechanisms of OS metastasis. In order to develop precise prognostic indicators and potential therapeutic targets for OS treatment, this review examines the molecular mechanisms of HIF-1α in the distant metastasis of OS cells; the signal transduction pathways mediated by HIF-1α are also discussed.

Disulfidptosis: Six Riddles Necessitating Solutions

Disulfidptosis occurs as a result of the accumulation of intracellular cystine followed by disulfide stress in actin cytoskeleton proteins due to a reduction of NADPH produced through the pentose phosphate pathway in cells with high expression of SLC7A11. It is a cell death caused by the redox imbalance resulting from the disruption of amino acid metabolism and glucose metabolism. The discovery of disulfidptosis has sparked immense enthusiasm, but there are numerous unresolved issues that need to be addressed. Solutions to these riddles will provide insights into the detailed mechanisms and the pathophysiological relevance of disulfidptosis and utilizing disulfidptosis as an actionable therapeutic target.

The tumor microenvironment: shaping cancer progression and treatment response

The tumor microenvironment (TME) plays a crucial role in cancer progression and treatment response. It comprises a complex network of stromal cells, immune cells, extracellular matrix, and blood vessels, all of which interact with cancer cells and influence tumor behaviour. This review article provides an in-depth examination of the TME, focusing on stromal cells, blood vessels, signaling molecules, and ECM, along with commonly available therapeutic compounds that target these components. Moreover, we explore the TME as a novel strategy for discovering new anti-tumor drugs. The dynamic and adaptive nature of the TME offers opportunities for targeting specific cellular interactions and signaling pathways. We discuss emerging approaches, such as combination therapies that simultaneously target cancer cells and modulate the TME. Finally, we address the challenges and future prospects in targeting the TME. Overcoming drug resistance, improving drug delivery, and identifying new therapeutic targets within the TME are among the challenges discussed. We also highlight the potential of personalized medicine and the integration of emerging technologies, such as immunotherapy and nanotechnology, in TME-targeted therapies. This comprehensive review provides insights into the TME and its therapeutic implications. Understanding the TME's complexity and targeting its components offer promising avenues for the development of novel anti-tumor therapies and improved patient outcomes.

Extracellular Matrix Cues Regulate Mechanosensing and Mechanotransduction of Cancer Cells

Extracellular biophysical properties have particular implications for a wide spectrum of cellular behaviors and functions, including growth, motility, differentiation, apoptosis, gene expression, cell-matrix and cell-cell adhesion, and signal transduction including mechanotransduction. Cells not only react to unambiguously mechanical cues from the extracellular matrix (ECM), but can occasionally manipulate the mechanical features of the matrix in parallel with biological characteristics, thus interfering with downstream matrix-based cues in both physiological and pathological processes. Bidirectional interactions between cells and (bio)materials in vitro can alter cell phenotype and mechanotransduction, as well as ECM structure, intentionally or unintentionally. Interactions between cell and matrix mechanics in vivo are of particular importance in a variety of diseases, including primarily cancer. Stiffness values between normal and cancerous tissue can range between 500 Pa (soft) and 48 kPa (stiff), respectively. Even the shear flow can increase from 0.1-1 dyn/cm2 (normal tissue) to 1-10 dyn/cm2 (cancerous tissue). There are currently many new areas of activity in tumor research on various biological length scales, which are highlighted in this review. Moreover, the complexity of interactions between ECM and cancer cells is reduced to common features of different tumors and the characteristics are highlighted to identify the main pathways of interaction. This all contributes to the standardization of mechanotransduction models and approaches, which, ultimately, increases the understanding of the complex interaction. Finally, both the in vitro and in vivo effects of this mechanics-biology pairing have key insights and implications for clinical practice in tumor treatment and, consequently, clinical translation.

Molecular weight-dependent antitumor effects of prunes-derived type I arabinogalactan on human and murine triple wild-type melanomas

The regulation of metastasis-related cellular aspects of two structurally similar AGIs from prunes tea infusion, with different molar masses, was studied in vitro against Triple Wild-Type metastatic melanoma (TWM) from murine and human origin. The higher molar mass AGI (AGI-78KDa) induced TWMs cells death and, in murine cell line, it decreased some metastasis-related cellular processes: invasiveness capacity, cell-extracellular matrix interaction, and colonies sizes. The lower molar mass AGI (AGI-12KDa) did not induce cell death but decreased TWMs proliferation rate and, in murine cell line, it decreased cell adhesion and colonies sizes. Both AGIs alter the clonogenic capacity of human cell line. In spite to understand why we saw so many differences between AGIs effects on murine and human cell lines we performed in silico analysis that demonstrated differential gene expression profiles between them. Complementary network topological predictions suggested that AGIs can modulate multiple pathways in a specie-dependent manner, which explain differential results obtained in vitro between cell lines. Our results pointed to therapeutic potential of AGIs from prunes tea against TWMs and showed that molecular weight of AGIs may influence their antitumor effects.

Development of Liver Cancer Organoids: Reproducing Tumor Microenvironment and Advancing Research for Liver Cancer Treatment

Liver cancer a leading cause of cancer-related deaths worldwide, yet understanding of its development mechanism remains limited, and treatment barriers present substantial challenges. Owing to the heterogeneity of tumors, traditional 2D culture models are inadequate for capturing the complexity and diversity of tumor biology and understanding of the disease. Organoids have garnered considerable attention because of their ability to self-renew and develop functional structures in vitro that closely resemble those of human organs. This review explores the history of liver organoids, their cellular origins, techniques of constructing tumor microenvironments that recapitulate liver cancer organoids, and the biological and clinical applications of liver and liver cancer organoids and explores the current challenges related to liver cancer organoid applications and potentially valuable solutions, with the aim of facilitating the construction of in vitro clinical models of liver cancer therapeutic research.

Piezo1 Is Required for Myoblast Migration and Involves Polarized Clustering in Association with Cholesterol and GM1 Ganglioside

A specific plasma membrane distribution of the mechanosensitive ion channel Piezo1 is required for cell migration, but the mechanism remains elusive. Here, we addressed this question using WT and Piezo1-silenced C2C12 mouse myoblasts and WT and Piezo1-KO human kidney HEK293T cells. We showed that cell migration in a cell-free area and through a porous membrane decreased upon Piezo1 silencing or deletion, but increased upon Piezo1 activation by Yoda1, whereas migration towards a chemoattractant gradient was reduced by Yoda1. Piezo1 organized into clusters, which were preferentially enriched at the front. This polarization was stimulated by Yoda1, accompanied by Ca2+ polarization, and abrogated by partial cholesterol depletion. Piezo1 clusters partially colocalized with cholesterol- and GM1 ganglioside-enriched domains, the proportion of which was increased by Yoda1. Mechanistically, Piezo1 activation induced a differential mobile fraction of GM1 associated with domains and the bulk membrane. Conversely, cholesterol depletion abrogated the differential mobile fraction of Piezo1 associated with clusters and the bulk membrane. In conclusion, we revealed, for the first time, the differential implication of Piezo1 depending on the migration mode and the interplay between GM1/cholesterol-enriched domains at the front during migration in a cell-free area. These domains could provide the optimal biophysical properties for Piezo1 activity and/or spatial dissociation from the PMCA calcium efflux pump.

Matrix Stiffness Regulated Endoplasmic Reticulum Stress-mediated Apoptosis of Osteosarcoma Cell through Ras Signal Cascades

The modulating effects of matrix stiffness on spreading and apoptosis of tumor cells have been well recognized. Nevertheless, the detail road map leading to the apoptosis and the underlying mechanisms governing the cell apoptosis have remained to be elucidated. To this aim, we provided a tunable elastic hydrogel matrix that promoted cell adhesion by modifying the surface of polyacrylamide with polydopamine, with stiffness value of 1, 10, 30, and 250 kPa, respectively. While the cell spreading increased and the apoptosis decreased with the matrix stiffness, such modulating effect of matrix on cell spreading exhibited different time evolvement behaviors as a function of stiffness, which likely led to surprisingly similar apoptosis rates for the 30 kPa and 250 kPa samples. Matrix stiffness mediated the spreading and apoptosis of MG-63 cells by regulating cell adhesion to matrix and in particular cytoskeletal organization, which was dependent on Ras, Rap1 and PI3K-Akt signaling pathways and finally led to the apoptosis of cancer cells dominated by endoplasmic reticulum stress pathway. Our results provided an insight into the regulation of tumor cell fate by the mechanical clues of ECM, which would have implication for future cancer research and the design of novel anticancer materials.

Charting a killer course to the solid tumor: strategies to recruit and activate NK cells in the tumor microenvironment

The ability to expand and activate natural Killer (NK) cells ex vivo has dramatically changed the landscape in the development of novel adoptive cell therapies for treating cancer over the last decade. NK cells have become a key player for cancer immunotherapy due to their innate ability to kill malignant cells while not harming healthy cells, allowing their potential use as an "off-the-shelf" product. Furthermore, recent advancements in NK cell genetic engineering methods have enabled the efficient generation of chimeric antigen receptor (CAR)-expressing NK cells that can exert both CAR-dependent and antigen-independent killing. Clinically, CAR-NK cells have shown promising efficacy and safety for treating CD19-expressing hematologic malignancies. While the number of pre-clinical studies using CAR-NK cells continues to expand, it is evident that solid tumors pose a unique challenge to NK cell-based adoptive cell therapies. Major barriers for efficacy include low NK cell trafficking and infiltration into solid tumor sites, low persistence, and immunosuppression by the harsh solid tumor microenvironment (TME). In this review we discuss the barriers posed by the solid tumor that prevent immune cell trafficking and NK cell effector functions. We then discuss promising strategies to enhance NK cell infiltration into solid tumor sites and activation within the TME. This includes NK cell-intrinsic and -extrinsic mechanisms such as NK cell engineering to resist TME-mediated inhibition and use of tumor-targeted agents such as oncolytic viruses expressing chemoattracting and activating payloads. We then discuss opportunities and challenges for using combination therapies to extend NK cell therapies for the treatment of solid tumors.

Biophysical phenotype mixtures reveal advantages for tumor muscle invasion in vivo

Bladder, colon, gastric, prostate, and uterine cancers originate in organs surrounded by laminin-coated smooth muscle. In human prostate cancer, tumors that are organ confined, without extracapsular extension through muscle, have an overall cancer survival rate of up to 97% compared with 32% for metastatic disease. Our previous work modeling extracapsular extension reported the blocking of tumor invasion by mutation of a laminin-binding integrin called α6β1. Expression of the α6AA mutant resulted in a biophysical switch from cell-ECM (extracellular matrix) to cell-cell adhesion with drug sensitivity properties and an inability to invade muscle. Here we used different admixtures of α6AA and α6WT cells to test the cell heterogeneity requirements for muscle invasion. Time-lapse video microscopy revealed that tumor mixtures self-assembled into invasive networks in vitro, whereas α6AA cells assembled only as cohesive clusters. Invasion of α6AA cells into and through live muscle occurred using a 1:1 mixture of α6AA and α6WT cells. Electric cell-substrate impedance sensing measurements revealed that compared with α6AA cells, invasion-competent α6WT cells were 2.5-fold faster at closing a cell-ECM or cell-cell wound, respectively. Cell-ECM rebuilding kinetics show that an increased response occurred in mixtures since the response was eightfold greater compared with populations containing only one cell type. A synthetic cell adhesion cyclic peptide called MTI-101 completely blocked electric cell-substrate impedance sensing cell-ECM wound recovery that persisted in vitro up to 20 h after the wound. Treatment of tumor-bearing animals with 10 mg/kg MTI-101 weekly resulted in a fourfold decrease of muscle invasion by tumor and a decrease of the depth of invasion into muscle comparable to the α6AA cells. Taken together, these data suggest that mixed biophysical phenotypes of tumor cells within a population can provide functional advantages for tumor invasion into and through muscle that can be potentially inhibited by a synthetic cell adhesion molecule.

Matrix stiffness triggers chemoresistance through elevated autophagy in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has a signature of extremely high matrix stiffness caused by a special desmoplastic reaction, which dynamically stiffens along with the pathological process. The poor prognosis and low five-year survival rate of PDAC are partly owing to chemoresistance triggered by substrate stiffness. Understanding the potential mechanisms of matrix stiffness causing PDAC chemoresistance is of great significance. In this study, methacrylated gelatin hydrogel was used as platform for PANC-1 and MIA-PaCa2 cell culture. The results indicated that compared to soft substrate, stiff substrate distinctively reduced the gemcitabine sensitivity of pancreatic cancer. Intriguingly, transmission electron microscopy, immunofluorescence staining, western blot and qRT-PCR assay showcased that the number of autophagosomes and the expression of LC3 were elevated. The observations indicate that matrix stiffness may regulate the autophagy level, which plays a vital role during chemoresistance. In brief, soft substrate exhibited low autophagy level, while the counterpart displayed elevated autophagy level. In order to elucidate the underlying interaction between matrix stiffness-mediated cell autophagy and chemoresistance, rescue experiments with rapamycin and chloroquine were conducted. We found that inhibiting cell autophagy dramatically increased the sensitivity of pancreatic cancer cells to gemcitabine in the stiff group, while promoting autophagy-driven chemoresistance in the soft group, demonstrating that matrix stiffness modulated chemoresistance via autophagy. Furthermore, RNA-seq results showed that miR-1972 may regulate autophagy level in response to matrix stiffness. Overall, our research shed light on the synergistic therapy of PDAC combined with gemcitabine and chloroquine, which is conducive to promoting a therapeutic effect.

Effect of substrate heterogeneity and topology on epithelial tissue growth dynamics

Tissue growth kinetics and interface dynamics depend on the properties of the tissue environment and cell-cell interactions. In cellular environments, substrate heterogeneity and geometry arise from a variety factors, such as the structure of the extracellular matrix and nutrient concentration. We used the CellSim3D model, a kinetic cell division simulator, to investigate the growth kinetics and interface roughness dynamics of epithelial tissue growth on heterogeneous substrates with varying topologies. The results show that the presence of quenched disorder has a clear effect on the colony morphology and the roughness scaling of the interface in the moving interface regime. In a medium with quenched disorder, the tissue interface has a smaller interface roughness exponent, α, and a larger growth exponent, β. The scaling exponents also depend on the topology of the substrate and cannot be categorized by well-known universality classes.

Extracellular Matrix Influences Gene Expression and Differentiation of Mouse Trophoblast Stem Cells

Trophoblast stem (TS) cells were first isolated from the mouse placenta; however, little is known about their maintenance and niche in vivo. TS cells, like other stem cells, have a unique microenvironment in which the extracellular matrix (ECM) is a component. Placental pathology is associated with ECM change. However, how these changes and the individual ECM components impact the maintenance or differentiation of TS cells has not been established. This study identified which ECM component(s) maintain the greatest expression of markers associated with undifferentiated mouse trophoblast stem (mTS) cells and which alter the profile of markers of differentiation based on mRNA analysis. mTS cells cultured on individual ECM components and subsequent quantitative polymerase chain reaction analysis revealed that laminin promoted the expression of markers associated with undifferentiated TS cells, fibronectin promoted gene expression associated with syncytiotrophoblast (SynT) layer II cells, and collagen IV promoted the expression of genes associated with differentiated trophoblast. To investigate whether pathological placental ECM influenced the expression of genes associated with different trophoblast subtypes, the mouse model of streptozotocin (STZ)-induced pancreatic β cell ablation and diabetes was used. Female mice administered STZ (blood glucose ≥300 mg/dL) or control (blood glucose ≤150 mg/dL) were mated. Placental pathology at embryonic day (E)14.5 was confirmed with reduced fetal blood space area, reduced expression of the pericyte marker αSMA, and decreased expression of ECM proteins. mTS cells cultured on ECM isolated from STZ placenta were associated with reduced expression of undifferentiated mTS markers and increased expression of genes associated with terminally differentiated trophoblast [Gcm-1 and SynA (SynT) and junctional zone Tpbpa and Prl2c2]. Altogether, these results support the value of using ECM isolated from the placenta as a tool for understanding trophoblast contribution to placental pathology.

Cell-Tissue Interaction: The Biomimetic Approach to Design Tissue Engineered Biomaterials

The advancement achieved in Tissue Engineering is based on a careful and in-depth study of cell-tissue interactions. The choice of a specific biomaterial in Tissue Engineering is fundamental, as it represents an interface for adherent cells in the creation of a microenvironment suitable for cell growth and differentiation. The knowledge of the biochemical and biophysical properties of the extracellular matrix is a useful tool for the optimization of polymeric scaffolds. This review aims to analyse the chemical, physical, and biological parameters on which are possible to act in Tissue Engineering for the optimization of polymeric scaffolds and the most recent progress presented in this field, including the novelty in the modification of the scaffolds' bulk and surface from a chemical and physical point of view to improve cell-biomaterial interaction. Moreover, we underline how understanding the impact of scaffolds on cell fate is of paramount importance for the successful advancement of Tissue Engineering. Finally, we conclude by reporting the future perspectives in this field in continuous development.

Immunomodulatory properties of the lymphatic endothelium in the tumor microenvironment

The tumor microenvironment (TME) is an intricate complex and dynamic structure composed of various cell types, including tumor, stromal and immune cells. Within this complex network, lymphatic endothelial cells (LECs) play a crucial role in regulating immune responses and influencing tumor progression and metastatic dissemination to lymph node and distant organs. Interestingly, LECs possess unique immunomodulatory properties that can either promote or inhibit anti-tumor immune responses. In fact, tumor-associated lymphangiogenesis can facilitate tumor cell dissemination and metastasis supporting immunoevasion, but also, different molecular mechanisms involved in LEC-mediated anti-tumor immunity have been already described. In this context, the crosstalk between cancer cells, LECs and immune cells and how this communication can shape the immune landscape in the TME is gaining increased interest in recent years. In this review, we present a comprehensive and updated report about the immunomodulatory properties of the lymphatic endothelium within the TME, with special focus on primary tumors and tumor-draining lymph nodes. Furthermore, we outline emerging research investigating the potential therapeutic strategies targeting the lymphatic endothelium to enhance anti-tumor immune responses. Understanding the intricate mechanisms involved in LEC-mediated immune modulation in the TME opens up new possibilities for the development of innovative approaches to fight cancer.