Laminin-332-rich tumor microenvironment for tumor invasion in the interface zone of breast cancer

Cancer-Associated Fibroblast Induces Acinar-to-Ductal Cell Transdifferentiation and Pancreatic Cancer Initiation Via LAMA5/ITGA4 Axis

BACKGROUND & AIMS

Pancreatic ductal adenocarcinoma (PDAC) is characterized by desmoplastic stroma surrounding most tumors. Activated stromal fibroblasts, namely cancer-associated fibroblasts (CAFs), play a major role in PDAC progression. We analyzed whether CAFs influence acinar cells and impact PDAC initiation, that is, acinar-to-ductal metaplasia (ADM). ADM connection with PDAC pathophysiology is indicated, but not yet established. We hypothesized that CAF secretome might play a significant role in ADM in PDAC initiation.

METHODS

Mouse and human acinar cell organoids, acinar cells cocultured with CAFs and exposed to CAF-conditioned media, acinar cell explants, and CAF cocultures were examined by means of quantitative reverse transcription polymerase chain reaction, RNA sequencing, immunoblotting, and confocal microscopy. Data from liquid chromatography with tandem mass spectrometry analysis of CAF-conditioned medium and RNA sequencing data of acinar cells post-conditioned medium exposure were integrated using bioinformatics tools to identify the molecular mechanism for CAF-induced ADM. Using confocal microscopy, immunoblotting, and quantitative reverse transcription polymerase chain reaction analysis, we validated the depletion of a key signaling axis in the cell line, acinar explant coculture, and mouse cancer-associated fibroblasts (mCAFs).

RESULTS

A close association of acino-ductal markers (Ulex europaeus agglutinin 1, amylase, cytokeratin-19) and mCAFs (α-smooth muscle actin) in LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx1Cre (KPC) and LSL-KrasG12D/+; Pdx1Cre (KC) autochthonous progression tumor tissue was observed. Caerulein treatment-induced mCAFs increased cytokeratin-19 and decreased amylase in wild-type and KC pancreas. Likewise, acinar-mCAF cocultures revealed the induction of ductal transdifferentiation in cell line, acinar-organoid, and explant coculture formats in WT and KC mice pancreas. Proteomic and transcriptomic data integration revealed a novel laminin α5/integrinα4/stat3 axis responsible for CAF-mediated acinar-to-ductal cell transdifferentiation.

CONCLUSIONS

Results collectively suggest the first evidence for CAF-influenced acino-ductal phenotypic switchover, thus highlighting the tumor microenvironment role in pancreatic carcinogenesis inception.

Biofabrication methods for reconstructing extracellular matrix mimetics

In the human body, almost all cells interact with extracellular matrices (ECMs), which have tissue and organ-specific compositions and architectures. These ECMs not only function as cellular scaffolds, providing structural support, but also play a crucial role in dynamically regulating various cellular functions. This comprehensive review delves into the examination of biofabrication strategies used to develop bioactive materials that accurately mimic one or more biophysical and biochemical properties of ECMs. We discuss the potential integration of these ECM-mimics into a range of physiological and pathological in vitro models, enhancing our understanding of cellular behavior and tissue organization. Lastly, we propose future research directions for ECM-mimics in the context of tissue engineering and organ-on-a-chip applications, offering potential advancements in therapeutic approaches and improved patient outcomes.

Inhibition of TGF-β signaling, invasion, and growth of cutaneous squamous cell carcinoma by PLX8394

Cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer. The prognosis of patients with metastatic cSCC is poor emphasizing the need for new therapies. We have previously reported that the activation of Ras/MEK/ERK1/2 and transforming growth factor β (TGF-β)/Smad2 signaling in transformed keratinocytes and cSCC cells leads to increased accumulation of laminin-332 and accelerated invasion. Here, we show that the next-generation B-Raf inhibitor PLX8394 blocks TGF-β signaling in ras-transformed metastatic epidermal keratinocytes (RT3 cells) harboring wild-type B-Raf and hyperactive Ras. PLX8394 decreased phosphorylation of TGF-β receptor II and Smad2, as well as p38 activity, MMP-1 and MMP-13 synthesis, and laminin-332 accumulation. PLX8394 significantly inhibited the growth of human cSCC tumors and in vivo collagen degradation in xenograft model. In conclusion, our data indicate that PLX8394 inhibits several serine-threonine kinases in malignantly transformed human keratinocytes and cSCC cells and inhibits cSCC invasion and tumor growth in vitro and in vivo. We identify PLX8394 as a potential therapeutic compound for advanced human cSCC.

Single-cell RNA reveals a tumorigenic microenvironment in the interface zone of human breast tumors

BACKGROUND

The interface zone, area around invasive carcinoma, can be thought of as the actual tissue of the tumor microenvironment with precedent alterations for tumor invasion. However, the heterogeneity and characteristics of the microenvironment in the interface area have not yet been thoroughly explored.

METHODS

For in vitro studies, single-cell RNA sequencing (scRNA-seq) was used to characterize the cells from the tumor zone, the normal zone and the interface zone with 5-mm-wide belts between the tumor invasion front and the normal zone. Through scRNA-seq data analysis, we compared the cell types and their transcriptional characteristics in the different zones. Pseudotime, cell-cell communication and pathway analysis were performed to characterize the zone-specific microenvironment. Cell proliferation, wound healing and clone formation experiments explored the function of differentially expressed gene BMPR1B, which were confirmed by tumor models in vivo.

RESULTS

After screening, 88,548 high-quality cells were obtained and identified. Regulatory T cells, M2 macrophages, angiogenesis-related mast cells, stem cells with weak DNA repair ability, endothelial cells with angiogenic activity, fibroblasts with collagen synthesis and epithelial cells with proliferative activity form a unique tumorigenic microenvironment in the interface zone. Cell-cell communication analysis revealed that there are special ligand-receptor pairs between different cell types in the interface zone, which protects endothelial cell apoptosis and promotes epithelial cell proliferation and migration, compared to the normal zone. Compared with the normal zone, the highly expressed BMPR1B gene promotes the tumorigenic ability of cancer cells in the interface zone.

CONCLUSIONS

Our work identified a unique tumorigenic microenvironment of the interface zone and allowed for deeper insights into the tumor microenvironment of breast cancer that will serve as a helpful resource for advancing breast cancer diagnosis and therapy.

Migration speed of captured breast cancer subpopulations correlates with metastatic fitness

The genetic alterations contributing to migration proficiency, a phenotypic hallmark of metastatic cells required for colonizing distant organs, remain poorly defined. Here, we used single-cell magneto-optical capture (scMOCa) to isolate fast cells from heterogeneous human breast cancer cell populations, based on their migratory ability alone. We show that captured fast cell subpopulations retain higher migration speed and focal adhesion dynamics over many generations as a result of a motility-related transcriptomic profile. Upregulated genes in isolated fast cells encoded integrin subunits, proto-cadherins and numerous other genes associated with cell migration. Dysregulation of several of these genes correlates with poor survival outcomes in people with breast cancer, and primary tumors established from fast cells generated a higher number of circulating tumor cells and soft tissue metastases in pre-clinical mouse models. Subpopulations of cells selected for a highly migratory phenotype demonstrated an increased fitness for metastasis.

Strategic outline of interventions targeting extracellular matrix for promoting healthy longevity

The extracellular matrix (ECM), composed of interlinked proteins outside of cells, is an important component of the human body that helps maintain tissue architecture and cellular homeostasis. As people age, the ECM undergoes changes that can lead to age-related morbidity and mortality. Despite its importance, ECM aging remains understudied in the field of geroscience. In this review, we discuss the core concepts of ECM integrity, outline the age-related challenges and subsequent pathologies and diseases, summarize diagnostic methods detecting a faulty ECM, and provide strategies targeting ECM homeostasis. To conceptualize this, we built a technology research tree to hierarchically visualize possible research sequences for studying ECM aging. This strategic framework will hopefully facilitate the development of future research on interventions to restore ECM integrity, which could potentially lead to the development of new drugs or therapeutic interventions promoting health during aging.

Extracellular Matrix Dynamics as an Emerging yet Understudied Hallmark of Aging and Longevity

The biomechanical properties of extracellular matrices (ECM) and their consequences for cellular homeostasis have recently emerged as a driver of aging. Here we review the age-dependent deterioration of ECM in the context of our current understanding of the aging processes. We discuss the reciprocal interactions of longevity interventions with ECM remodeling. And the relevance of ECM dynamics captured by the matrisome and the matreotypes associated with health, disease, and longevity. Furthermore, we highlight that many established longevity compounds promote ECM homeostasis. A large body of evidence for the ECM to qualify as a hallmark of aging is emerging, and the data in invertebrates is promising. However, direct experimental proof that activating ECM homeostasis is sufficient to slow aging in mammals is lacking. We conclude that further research is required and anticipate that a conceptual framework for ECM biomechanics and homeostasis will provide new strategies to promote health during aging.

[Immunopathogenesis of mucous membrane pemphigoid]

A detailed understanding of the immunopathogenesis of mucous membrane pemphigoid (MMP) is of particular importance in view of the mostly difficult diagnostics and treatment of this blistering autoimmune dermatosis. A still unknown disturbance of the body's own immune tolerance leads to the formation of autoreactive cells. As the disease progresses these produce autoantibodies which are directed against structural proteins in the basement membrane zone (BMZ). After they bind to the target antigen, complement factors are deposited along the BMZ and inflammatory cells invade the underlying tissue and produce the characteristic subepithelial blistering. This inflammatory response is associated with fibrosis and scarring in many affected tissues. Most phases of MMP pathogenesis are poorly understood; however, the last few years have shed more light on this processes. These advances are mostly the result of animal and cell culture models. Typical clinical and immunopathological characteristics of MMP, such as oral, conjunctival and skin lesions, are reflected, for example, in an antibody transfer-induced mouse model for anti-laminin 332 MMP in adult mice. Dapsone, as first-line treatment for MMP patients, significantly reduced the severity of these symptoms, and fibrosis in the skin and mucous membranes was also found histologically, which makes the model well-suited for testing new therapeutic approaches for MMP patients and might be of help for further elucidation of the immunopathogenesis of MMP.

Connexins orchestrate progression of breast cancer metastasis to the brain by promoting FAK activation

Brain metastasis is a complication of increasing incidence in patients with breast cancer at advanced disease stage. It is a severe condition characterized by a rapid decline in quality of life and poor prognosis. There is a critical clinical need to develop effective therapies to prevent and treat brain metastases. Here, we describe a unique and robust spontaneous preclinical model of breast cancer metastasis to the brain (4T1-BM₂) in mice that has been instrumental in uncovering molecular mechanisms guiding metastatic dissemination and colonization of the brain. Key experimental findings were validated in the additional murine D2A1-BM₂ model and in human MDA231-BrM₂ model. Gene expression analyses and functional studies, coupled with clinical transcriptomic and histopathological investigations, identified connexins (Cxs) and focal adhesion kinase (FAK) as master molecules orchestrating breast cancer colonization of the brain. Cx31 promoted homotypic tumor cell adhesion, heterotypic tumor-astrocyte interaction, and FAK phosphorylation. FAK signaling prompted NF-κB activation inducing Lamc2 expression and laminin 332 (laminin 5) deposition, α6 integrin-mediated adhesion, and sustained survival and growth within brain parenchyma. In the MDA231-BrM₂ model, the human homologous molecules CX43, LAMA4, and α3 integrin were involved. Systemic treatment with FAK inhibitors reduced brain metastasis progression. In conclusion, we report a spontaneous model of breast cancer metastasis to the brain and identified Cx-mediated FAK-NF-κB signaling as a mechanism promoting cell-autonomous and microenvironmentally controlled cell survival for brain colonization. Considering the limited therapeutic options for brain metastatic disease in cancer patients, we propose FAK as a therapeutic candidate to further pursue in the clinic.

The biomimetic extracellular matrix: a therapeutic tool for breast cancer research

A deeper knowledge of the functional versatility and dynamic nature of the ECM has improved the understanding of cancer biology. Translational Significance: This work provides an in-depth view of the importance of the ECM to develop more mimetic breast cancer models, which aim to recreate the components and architecture of tumor microenvironment. Special focus is placed on decellularized matrices derived from tissue and cell culture, both in procurement and applications, as they have achieved great success in cancer research and pharmaceutical sector. The extracellular matrix (ECM) is increasingly recognized as a master regulator of cell behavior and response to breast cancer (BC) treatment. During BC progression, the mammary gland ECM is remodeled and altered in the composition and organization. Accumulated evidence suggests that changes in the composition and mechanics of ECM, orchestrated by tumor-stromal interactions along with ECM remodeling enzymes, are actively involved in BC progression and metastasis. Understanding how specific ECM components modulate the tumorigenic process has led to an increased interest in the development of biomaterial-based biomimetic ECM models to recapitulate key tumor characteristics. The decellularized ECMs (dECMs) have emerged as a promising in vitro 3D tumor model, whose recent advances in the processing and application could become the biomaterial by excellence for BC research and the pharmaceutical industry. This review offers a detailed view of the contribution of ECM in BC progression, and highlights the application of dECM-based biomaterials as promising personalized tumor models that more accurately mimic the tumorigenic mechanisms of BC and the response to treatment. This will allow the design of targeted therapeutic approaches adapted to the specific characteristics of each tumor that will have a great impact on the precision medicine applied to BC patients.

Transcriptome Analysis of Liver Cancer Cell Huh-7 Treated With Metformin

Metformin is a kind of widely used antidiabetic drug that regulates glucose homeostasis by inhibiting liver glucose production and increasing muscle glucose uptake. Recently, some studies showed that metformin exhibits anticancer properties in a variety of cancers. Although several antitumor mechanisms have been proposed for metformin action, its mode of action in human liver cancer remains not elucidated. In our study, we investigated the underlying molecular mechanisms of metformin's antitumor effect on Huh-7 cells of hepatocellular carcinoma (HCC) in vitro. RNA sequencing was performed to explore the effect of metformin on the transcriptome of Huh-7 cells. The results revealed that 4,518 genes (with log2 fold change > 1 or < −1, adjusted p-value < 0.05) were differentially expressed in Huh-7 cells with treatment of 25-mM metformin compared with 0-mM metformin, including 1,812 upregulated and 2,706 downregulated genes. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses identified 54 classical pathways that were significantly enriched, and 16 pathways are closely associated with cancer, such as cell cycle, DNA replication, extracellular matrix–receptor interaction, and so on. We selected 11 differentially expressed genes, which are closely associated with HCC, to validate their differential expressions through a quantitative real-time reverse transcription-polymerase chain reaction. The result exhibited that the genes of fatty acid synthase, mini-chromosome maintenance complex components 6 and 5, myristoylated alanine-rich C-kinase substrate, fatty acid desaturase 2, C-X-C motif chemokine ligand 1, bone morphogenetic protein 4, S-phase kinase-associated protein 2, kininogen 1, and proliferating cell nuclear antigen were downregulated, and Dual-specificity phosphatase-1 is significantly upregulated in Huh-7 cells with treatment of 25-mM metformin. These differentially expressed genes and pathways might play a crucial part in the antitumor effect of metformin and might be potential targets of metformin treating HCC. Further investigations are required to evaluate the metformin mechanisms of anticancer action in vivo.

Cartilage oligomeric matrix protein as a non-invasive biomarker for diagnosis of hepatocellular carcinoma in patients with liver cirrhosis

Aim

The current study purposed to evaluate serum COMP (Cartilage oligomeric matrix protein) as a diagnostic marker for HCC in patients with cirrhosis and to correlate it with other parameters of disease progression.

Background

COMP is known to promote fibrosis in various tissues. Emerging evidence shows that COMP plays critical roles in tumor development. It can serve as a fibrosis and cancer biomarkers.

Methods

The study included 24 subjects who serve as the healthy control, 24 cirrhotic patients without HCC, and 24 HCC patients with cirrhosis. All participants were subjected to liver function tests, AFP, calculation of fibrotic indices (APRI and FIB-4), and serum COMP by ELISA.

Results

COMP was significantly increased in cirrhotic patients when compared to healthy controls and in HCC patients when compared to cirrhotic patients and healthy controls. A significant positive correlation was observed between COMP and APRI and FIB-4 in cirrhotic and HCC patients. Based on receiver operating characteristic (ROC) curve analysis, COMP had an area under curve (AUC) of 0.943 with 87.5% sensitivity and 79.2% specificity for diagnosis of HCC in cirrhotic patients. In combination with AFP, the sensitivity was increased to 100%.

Conclusion

COMP might act as a promising non-invasive biomarker for HCC either alone or in combination with AFP. It was correlated with the degree of fibrosis and associated with advanced cancer staging.

Remodelling of the fibre-aggregate structure of collagen gels by cancer-associated fibroblasts: A time-resolved grey-tone image analysis based on stochastic modelling

Introduction

Solid tumors consist of tumor cells associated with stromal and immune cells, secreted factors and extracellular matrix (ECM), which together constitute the tumor microenvironment. Among stromal cells, activated fibroblasts, known as cancer-associated fibroblasts (CAFs) are of particular interest. CAFs secrete a plethora of ECM components including collagen and modulate the architecture of the ECM, thereby influencing cancer cell migration. The characterization of the collagen fibre network and its space and time-dependent microstructural modifications is key to investigating the interactions between cells and the ECM. Developing image analysis tools for that purpose is still a challenge because the structural complexity of the collagen network calls for specific statistical descriptors. Moreover, the low signal-to-noise ratio of imaging techniques available for time-resolved studies rules out standard methods based on image segmentation.

Methods

In this work, we develop a novel approach based on the stochastic modelling of the gel structure and on grey-tone image analysis. The method is then used to study the remodelling of a collagen matrix by migrating breast cancer-derived CAFs in a three-dimensional spheroid model of cellular invasion imaged by time-lapse confocal microscopy.

Results

The structure of the collagen at the scale of a few microns consists in regions with high fibre density separated by depleted regions, which can be thought of as aggregates and pores. The approach developped captures this two-scale structure with a clipped Gaussian field model to describe the aggregates-and-pores large-scale structure, and a homogeneous Boolean model to describe the small-scale fibre network within the aggregates. The model parameters are identified by fitting the grey-tone histograms and correlation functions of the images. The method applies to unprocessed grey-tone images, and it can therefore be used with low magnification, noisy time-lapse reflectance images. When applied to the CAF spheroid time-resolved images, the method reveals different matrix densification mechanisms for the matrix in direct contact or far from the cells.

Conclusion

We developed a novel and multidisciplinary image analysis approach to investigate the remodelling of fibrillar collagen in a 3D spheroid model of cellular invasion. The specificity of the method is that it applies to the unprocessed grey-tone images, and it can therefore be used with noisy time-lapse reflectance images of non-fluorescent collagen. When applied to the CAF spheroid time-resolved images, the method reveals different matrix densification mechanisms for the matrix in direct contact or far from the cells.

Influence of Tumor Microenvironment and Fibroblast Population Plasticity on Melanoma Growth, Therapy Resistance and Immunoescape

Cutaneous melanoma (CM) tissue represents a network constituted by cancer cells and tumor microenvironment (TME). A key feature of CM is the high structural and cellular plasticity of TME, allowing its evolution with disease and adaptation to cancer cell and environmental alterations. In particular, during melanoma development and progression each component of TME by interacting with each other and with cancer cells is subjected to dramatic structural and cellular modifications. These alterations affect extracellular matrix (ECM) remodelling, phenotypic profile of stromal cells, cancer growth and therapeutic response. The stromal fibroblast populations of the TME include normal fibroblasts and melanoma-associated fibroblasts (MAFs) that are highly abundant and flexible cell types interacting with melanoma and stromal cells and differently influencing CM outcomes. The shift from the normal microenvironment to TME and from normal fibroblasts to MAFs deeply sustains CM growth. Hence, in this article we review the features of the normal microenvironment and TME and describe the phenotypic plasticity of normal dermal fibroblasts and MAFs, highlighting their roles in normal skin homeostasis and TME regulation. Moreover, we discuss the influence of MAFs and their secretory profiles on TME remodelling, melanoma progression, targeted therapy resistance and immunosurveillance, highlighting the cellular interactions, the signalling pathways and molecules involved in these processes.

Transcriptome Analysis of MDA-MB-231 Cells Treated with Fumosorinone Isolated from Insect Pathogenic Fungi

BACKGROUND

In our previous study, we have isolated a new compound, named Fumosorinone (FU) from insect pathogenic fungi, and was found to inhibit proliferation, migration, and invasion of breast cancer MDA-MB-231 cells.

OBJECTIVE

The aim of this study was to identify the underlying molecular mechanisms for FU effects on MDAMB- 231 cells.

METHODS

After MDA-MB-231 cells were treated with FU for 48h, RNA sequencing was used to identify the effect of FU on the transcriptome of MDA-MB-231 cells. The validation of the relative expression of the selective genes was done using quantitative real-time PCR (qRT-PCR).

RESULTS

The transcriptome results showed that 2733 genes were differentially expressed between the untreated and the FU-treated cells, including 1614 up-regulated and 1119 down-regulated genes. The multiple genes are associated with cancer cell growth, migration, and invasion. Functional analysis identified multitude of pathways related to cancer, such as cell cycle, ECM-receptor interaction, p53 signaling pathway. We selected 4 upregulated and 9 downregulated genes, which are associated with breast cancer to verify their expression using qRT-PCR. The validation showed that HSD3B1, ALOX5, AQP5, COL1A2, CCNB1, CCND1, VCAM-1, PTPN1 and PTPN11 were significantly downregulated while DUSP1, DUSP5, GADD45A, EGR1 were upregulated in FU-treated MDA-MB-231cells.

CONCLUSION

These aberrantly expressed genes and pathways may play pivotal roles in the anti-cancer activity of FU, and maybe potential targets of FU treatments for TNBC. Further investigations are required to evaluate the FU mechanisms of anti-cancer action in vivo.

Hold on or Cut? Integrin- and MMP-Mediated Cell-Matrix Interactions in the Tumor Microenvironment

The tumor microenvironment (TME) has become the focus of interest in cancer research and treatment. It includes the extracellular matrix (ECM) and ECM-modifying enzymes that are secreted by cancer and neighboring cells. The ECM serves both to anchor the tumor cells embedded in it and as a means of communication between the various cellular and non-cellular components of the TME. The cells of the TME modify their surrounding cancer-characteristic ECM. This in turn provides feedback to them via cellular receptors, thereby regulating, together with cytokines and exosomes, differentiation processes as well as tumor progression and spread. Matrix remodeling is accomplished by altering the repertoire of ECM components and by biophysical changes in stiffness and tension caused by ECM-crosslinking and ECM-degrading enzymes, in particular matrix metalloproteinases (MMPs). These can degrade ECM barriers or, by partial proteolysis, release soluble ECM fragments called matrikines, which influence cells inside and outside the TME. This review examines the changes in the ECM of the TME and the interaction between cells and the ECM, with a particular focus on MMPs.

In Vitro Modeling of the Tumor Microenvironment in Tumor Organoids

BACKGROUND

The tumor microenvironment (TME) represents the many components occupying the space within and surrounding a tumor, including cells, signaling factors, extracellular matrix, and vasculature. Each component has the potential to assume many forms and functions which in turn contribute to the overall state of the TME, and further contribute to the progression and disposition of the tumor itself. The sum of these components can drive a tumor towards progression, keep a migratory tumor at bay, or even control chemotherapeutic response. The wide potential for interaction that the TME is an integral part of a tumor's ecosystem, and it is imperative to include it when studying and modeling cancer in vitro. Fortunately, the development of tissue engineering and biofabrication technologies and methodologies have allowed widespread inclusion of TME-based factors into in vitro tissue-equivalent models.

METHODS

In this review, we compiled contemporary literature sources to provide an overview of the field of TME models, ranging from simple to complex.

RESULTS

We have identified important components of the TME, how they can be included in in vitro study, and cover examples across a range of cancer types.

CONCLUSION

Our goal with this text is to provide a foundation for prospective research into the TME.

H-Ras activation and fibroblast-induced TGF-β signaling promote laminin-332 accumulation and invasion in cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer, with increasing incidence worldwide. The molecular basis of cSCC progression to invasive and metastatic disease is still incompletely understood. Here, we show that fibroblasts and transforming growth factor-β (TGF-β) signaling promote laminin-332 synthesis in cancer cells in an activated H-Ras-dependent manner, which in turn promotes cancer cell invasion. Immunohistochemical analysis of sporadic UV-induced invasive human cSCCs (n = 208) revealed prominent cSCC cell specific immunostaining for laminin-332 γ2 chain, located in the majority of cases (90%, n = 173) in the invasive edge of the tumors. To mimic the progression of cSCC we established 3D spheroid cocultures using primary skin fibroblasts and HaCaT/ras-HaCaT human keratinocytes. Our results indicate that in 3D spheroids, unlike in monolayer cultures, TGF-β upregulates laminin-332 production, but only in cells that harbour oncogenic H-Ras. Accumulation of laminin-332 was prevented by both H-Ras knock down and inhibition of TGF-β signaling by SB431542 or RAdKD-ALK5 kinase-defective adenovirus. Furthermore, fibroblasts accelerated the invasion of ras-HaCaT cells through collagen I gels in a Ras/TGF-β signaling dependent manner. In conclusion, we demonstrate the presence of laminin-332 in the invasive front of cSCC tumors and report a new Ras/TGF-β-dependent mechanism that promotes laminin-332 accumulation and cancer cell invasion.

Laminin 332 in cancer: When the extracellular matrix turns signals from cell anchorage to cell movement

Laminin 332 is crucial in the biology of epithelia. This large extracellular matrix protein consists of the heterotrimeric assembly of three subunits - α3, β3, and γ2 - and its multifunctionality relies on a number of extracellular proteolytic processing events. Laminin 332 is central to normal epithelium homeostasis by sustaining cell adhesion, polarity, proliferation, and differentiation. It also supports a major function in epithelial tissue formation, repair, and regeneration by buttressing cell migration and survival and basement membrane assembly. Interest in this protein increased after the discovery that its expression is perturbed in tumor cells, cancer-associated fibroblasts, and the tumor microenvironment. This review summarizes current knowledge regarding the established involvement of the laminin 332 γ2 chain in tumor invasiveness and discusses the role of its α3 and β3 subunits.

The Tumor Microenvironment: Focus on Extracellular Matrix

The extracellular matrix (ECM) regulates the development and maintains tissue homeostasis. The ECM is composed of a complex network of molecules presenting distinct biochemical properties to regulate cell growth, survival, motility, and differentiation. Among their components, proteoglycans (PGs) are considered one of the main components of ECM. Its composition, biomechanics, and anisotropy are exquisitely tuned to reflect the physiological state of the tissue. The loss of ECM's homeostasis is seen as one of the hallmarks of cancer and, typically, defines transitional events in tumor progression and metastasis. In this chapter, we discuss the types of proteoglycans and their roles in cancer. It has been observed that the amount of some ECM components is increased, while others are decreased, depending on the type of tumor. However, both conditions corroborate with tumor progression and malignancy. Therefore, ECM components have an increasingly important role in carcinogenesis and this leads us to believe that their understanding may be a key in the discovery of new anti-tumor therapies. In this book, the main ECM components will be discussed in more detail in each chapter.

The stromal loss of miR-4516 promotes the FOSL1-dependent proliferation and malignancy of triple negative breast cancer

Stroma-derived exosomal microRNA (exomiR) contributes to tumor progression, however, which remains poorly understood. In our study, we analyzed exomiRs from the cancer-associated fibroblast (CAF) and normal fibroblast (NF) isolated from an invasive ductal carcinoma (IDC) patient and found that the level of microRNA (miR)-4516 was approximately 5-fold lower in CAF-derived exosomes than NF-derived ones. In gene annotation analysis, miR-4516 target genes were mainly associated with the regulation of proliferation. miR-4516 overexpression or mimic treatment suppressed the proliferation of breast cancer cells, especially triple negative breast cancer (TNBC) cells. Among miR-4516 targets, FOSL1 was overexpressed in TNBC cells compared to non-TNBC cells and promoted tumor proliferation. The expression of miR-4516 and FOSL1 was reversely correlated in breast cancer patient tissues. Particularly, TNBC patients with high FOSL1 expression showed a significant poorer survival than those with low FOSL1 expression. Our results show that the loss of miR-4516 from CAF-derived exosomes is associated with FOSL1-dependent TNBC progression and suggest that miR-4516 can be used as an anti-cancer drug for TNBC.

ITGB4-mediated metabolic reprogramming of cancer-associated fibroblasts

Integrin beta 4 (ITGB4) overexpression in cancer cells contributes to cancer progression. However, the role of stromal ITGB4 expression in cancer progression remains poorly understood, despite stromal ITGB4 overexpression in malignant cancers. In our study, ITGB4-overexpressing triple negative breast cancer (TNBC) cells provided cancer-associated fibroblasts (CAFs) with ITGB4 proteins via exosomes, which induced BNIP3L-dependent mitophagy and lactate production in CAFs. In coculture assays, the ITGB4-induced mitophagy and glycolysis were suppressed in CAFs by knocking down ITGB4 or inhibiting exosome generation in MDA-MB-231, or blocking c-Jun or AMPK phosphorylation in CAFs. ITGB4-overexpressing CAF-conditioned medium promoted the proliferation, epithelial-to-mesenchymal transition, and invasion of breast cancer cells. In a co-transplant mouse model, MDA-MB-231 made a bigger tumor mass with CAFs than ITGB4 knockdown MDA-MB-231. Herein, we presented how TNBC-derived ITGB4 protein triggers glycolysis in CAFs via BNIP3L-dependent mitophagy and suggested the possibility that ITGB4-induced mitophagy could be targeted as a cancer therapy.

Compression-induced expression of glycolysis genes in CAFs correlates with EMT and angiogenesis gene expression in breast cancer

Tumor growth increases compressive stress within a tissue, which is associated with solid tumor progression. However, very little is known about how compressive stress contributes to tumor progression. Here, we show that compressive stress induces glycolysis in human breast cancer associated fibroblast (CAF) cells and thereby contributes to the expression of epithelial to mesenchymal (EMT)- and angiogenesis-related genes in breast cancer cells. Lactate production was increased in compressed CAF cells, in a manner dependent on the expression of metabolic genes ENO2, HK2, and PFKFB3. Conditioned medium from compressed CAFs promoted the proliferation of breast cancer cells and the expression of EMT and/or angiogenesis-related genes. In patient tissues with high compressive stress, the expression of compression-induced metabolic genes was significantly and positively correlated with EMT and/or angiogenesis-related gene expression and metastasis size. These findings illustrate a mechanotransduction pathway involving stromal glycolysis that may be relevant also for other solid tumours.

Identification of key genes in osteosarcoma by meta‑analysis of gene expression microarray

Osteosarcoma (OS) is one of the most malignant tumors in children and young adults. To better understand the underlying mechanism, five related datasets deposited in the Gene Expression Omnibus were included in the present study. The Bioconductor ‘limma’ package was used to identify differentially expressed genes (DEGs) and the ‘Weighted Gene Co-expression Network Analysis’ package was used to construct a weighted gene co-expression network to identify key modules and hub genes, associated with OS. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes overrepresentation analyses were used for functional annotation. The results indicated that 1,405 genes were dysregulated in OS, including 927 upregulated and 478 downregulated genes, when the cut off value was set at a ≥2 fold-change and an adjusted P-value of P<0.01 was used. Functional annotation of DEGs indicated that these genes were involved in the extracellular matrix (ECM) and that they function in several processes, including biological adhesion, ECM organization, cell migration and leukocyte migration. These findings suggested that dysregulation of the ECM shaped the tumor microenvironment and modulated the OS hallmark. Genes assigned to the yellow module were positively associated with OS and could contribute to the development of OS. In conclusion, the present study has identified several key genes that are potentially druggable genes or therapeutics targets in OS. Functional annotations revealed that the dysregulation of the ECM may contribute to OS development and, therefore, provided new insights to improve our understanding of the mechanisms underlying OS.

The extracellular matrix in tumor progression and metastasis

The extracellular matrix (ECM) constitutes the scaffold of tissues and organs. It is a complex network of extracellular proteins, proteoglycans and glycoproteins, which form supramolecular aggregates, such as fibrils and sheet-like networks. In addition to its biochemical composition, including the covalent intermolecular cross-linkages, the ECM is also characterized by its biophysical parameters, such as topography, molecular density, stiffness/rigidity and tension. Taking these biochemical and biophysical parameters into consideration, the ECM is very versatile and undergoes constant remodeling. This review focusses on this remodeling of the ECM under the influence of a primary solid tumor mass. Within this tumor stroma, not only the cancer cells but also the resident fibroblasts, which differentiate into cancer-associated fibroblasts (CAFs), modify the ECM. Growth factors and chemokines, which are tethered to and released from the ECM, as well as metabolic changes of the cells within the tumor bulk, add to the tumor-supporting tumor microenvironment. Metastasizing cancer cells from a primary tumor mass infiltrate into the ECM, which variably may facilitate cancer cell migration or act as barrier, which has to be proteolytically breached by the infiltrating tumor cell. The biochemical and biophysical properties therefore determine the rates and routes of metastatic dissemination. Moreover, primed by soluble factors of the primary tumor, the ECM of distant organs may be remodeled in a way to facilitate the engraftment of metastasizing cancer cells. Such premetastatic niches are responsible for the organotropic preference of certain cancer entities to colonize at certain sites in distant organs and to establish a metastasis. Translational application of our knowledge about the cancer-primed ECM is sparse with respect to therapeutic approaches, whereas tumor-induced ECM alterations such as increased tissue stiffness and desmoplasia, as well as breaching the basement membrane are hallmark of malignancy and diagnostically and histologically harnessed.

Cancer Mechanobiology: Microenvironmental Sensing and Metastasis

The cellular microenvironment plays an important role in regulating cancer progress. Cancer can physically and chemically remodel its surrounding extracellular matrix (ECM). Critical cellular behaviors such as recognition of matrix geometry and rigidity, cell polarization and motility, cytoskeletal reorganization, and proliferation can be changed as a consequence of these ECM alternations. Here, we present an overview of cancer mechanobiology in detail, focusing on cancer microenvironmental sensing of exogenous cues and quantification of cancer-substrate interactions. In addition, mechanics of metastasis classified with tumor progression will be discussed. The mechanism underlying cancer mechanosensation and tumor progression may provide new insights into therapeutic strategies to alleviate cancer malignancy.

The Interaction between Laminin-332 and α3β1 Integrin Determines Differentiation and Maintenance of CAFs, and Supports Invasion of Pancreatic Duct Adenocarcinoma Cells

Ranking among the most lethal tumour entities, pancreatic duct adenocarcinoma cells invade neighbouring tissue resulting in high incidence of metastasis. They are supported by tumour stroma fibroblasts which have undergone differentiation into cancer-associated fibroblasts (CAFs). Stiffness of cell substratum, cytokines, such as transforming growth factor-β (TGF-β), and stromal matrix proteins, such as laminin-332, are factors which promote CAF differentiation. In a spheroid culture system, differentiation of CAFs was analysed for laminin-332 production, laminin-binding integrin repertoire, adhesion and migration behaviour, and, in heterospheroids, for their interplay with the pancreatic duct adenocarcinoma AsPC-I cells. Our data reveal that CAFs produce laminin-332 thus contributing to its ectopic deposition within the tumour stroma. Moreover, CAF differentiation correlates with an increased expression of α3β1 integrin, the principal laminin-332-receptor. Beyond its role as novel CAF marker protein, integrin α3β1 crucially determines differentiation and maintenance of the CAF phenotype, as knock-out of the integrin α3 subunit reversed the CAF differentiated state. AsPC-I cells co-cultured in heterospheroids with integrin α3-deficient CAFs invaded less than from heterospheroids with wild-type CAFs. This study highlights the role of integrin α3β1 integrin-laminin-332 interaction of CAFs which promotes and sustains differentiation of CAFs and promotes carcinoma invasion.

Laminin 332 expression and prognosis in breast cancer

The purpose of this study was to determine the distribution of and potential significance of laminin 332 (LM332) in breast cancer. Specimens from a population-based cohort (N = 297) from 1994 to 1995 were stained for estrogen receptor (ER), progesterone receptor (PgR), HER2 and the LM332 β3 chain. Seventy-five tumors were LM332-positive and 222 were negative. LM332 β3 stained 16.0% of ER and/or PgR-positive tumors and 73.2% of triple-negative breast cancers (TNBC). Immunoblotting revealed LM332 in TNBC and HER2-positive samples, but not in an ER-positive breast carcinoma or a phyllodes tumor. After 20 years, 172 patients were alive, 43 had died of breast cancer and 82 of other causes. Patients with LM332-positive tumors had significantly worse 5 (P < .0001) and 10-year (P < .05) overall and breast cancer specific survival. Among patients with LM332 β3-expressing and ER/PgR-negative carcinomas, 10-year survival was significantly reduced (P < .0450). In a multivariate analysis LM332-positive patients had significant hazard ratios of 3.9 with 95% confidence intervals (CI) of 2.0-7.7 and 2.2 with 95% CI of 1.3-3.8 for 5 and 10-year overall survival, respectively. Because tumor cell motility is required for metastasis, the effect of LM332 on MDA-MB-231 migration was determined using siRNA. Knockdown of LM332-specific β3 and γ2 chains reduced motility without affecting viability. Our observation that LM332 in breast carcinoma is associated with decreased survival provides evidence that LM332 may have a role in the aggressive phenotype of some breast cancers.

Microenvironmental Signals and Biochemical Information Processing: Cooperative Determinants of Intratumoral Plasticity and Heterogeneity

Intra-tumor cellular heterogeneity is a major challenge in cancer therapy. Tumors are composed of multiple phenotypic subpopulations that vary in their ability to initiate metastatic tumors and in their sensitivity to chemotherapy. In many cases, cells can transition between these subpopulations, not by genetic mutation, but instead through reversible changes in signal transduction or gene expression programs. This plasticity begins at the level of the microenvironment where local autocrine and paracrine signals, exosomes, tumor–stroma interactions, and extracellular matrix (ECM) composition create a signaling landscape that varies over space and time. The integration of this complex array of signals engages signaling pathways that control gene expression. The resulting modulation of gene expression programs causes individual cells to sample a wide array of phenotypic states that support tumor growth, dissemination, and therapeutic resistance. In this review, we discuss how information flows dynamically within the microenvironmental landscape to inform cell state decisions and to create intra-tumoral heterogeneity. We address the role of plasticity in the acquisition of transient and prolonged drug resistant states and discuss how targeted pharmacological modification of the signaling landscape may be able to constrain phenotypic plasticity, leading to improved treatment responses.

Baicalein disturbs the morphological plasticity and motility of breast adenocarcinoma cells depending on the tumor microenvironment

During tumor invasion, cancer cells change their morphology and mode of migration based on communication with the surrounding environment. Numerous studies have indicated that paracrine interactions from non-neoplastic cells impact the migratory and invasive properties of cancer cells. Thus, these interactions are potential targets for anticancer therapies. In this study, we showed that the flavones member baicalein suppresses the motility of breast cancer cells that is promoted by paracrine interactions. First, we identified laminin-332 (LN-332) as a principle paracrine factor in conditioned medium from mammary epithelium-derived MCF10A cells that regulates the morphology and motility of breast adenocarcinoma MDA-MB-231 cells. Then, we carried out a morphology-based screen for small compounds, which showed that baicalein suppressed the morphological changes and migratory activity of MDA-MB-231 cells that were induced by conditioned medium from MCF10A cells and LN-332. We also found that baicalein caused narrower and incomplete lamellipodia formation in conditioned medium-treated MDA-MB-231 cells, although actin dynamics downstream of Rho family small GTPases were unaffected. These results suggest the importance of mammary epithelial cells in the cancer microenvironment promoting the migratory activity of breast adenocarcinoma cells and show a novel mechanism through which baicalein inhibits cancer cell motility.

Human Epididymis Protein 4 Promotes Events Associated with Metastatic Ovarian Cancer via Regulation of the Extracelluar Matrix

Human epididymis protein 4 (HE4) has received much attention recently due to its diagnostic and prognostic abilities for epithelial ovarian cancer. Since its inclusion in the Risk of Ovarian Malignancy Algorithm (ROMA), studies have focused on its functional effects in ovarian cancer. Here, we aimed to investigate the role of HE4 in invasion, haptotaxis, and adhesion of ovarian cancer cells. Furthermore, we sought to gain an understanding of relevant transcriptional profiles and protein kinase signaling pathways mediated by this multifunctional protein. Exposure of OVCAR8 ovarian cancer cells to recombinant HE4 (rHE4) promoted invasion, haptotaxis toward a fibronectin substrate, and adhesion onto fibronectin. Overexpression of HE4 or treatment with rHE4 led to upregulation of several transcripts coding for extracellular matrix proteins, including SERPINB2, GREM1, LAMC2, and LAMB3. Gene ontology indicated an enrichment of terms related to extracellular matrix, cell migration, adhesion, growth, and kinase phosphorylation. LAMC2 and LAMB3 protein levels were constitutively elevated in cells overexpressing HE4 and were upregulated in a time-dependent manner in cells exposed to rHE4 in the media. Deposition of laminin-332, the heterotrimer comprising LAMC2 and LAMB3 proteins, was increased in OVCAR8 cells treated with rHE4 or conditioned media from HE4-overexpressing cells. Enzymatic activity of matriptase, a serine protease that cleaves laminin-332 and contributes to its pro-migratory functional activity, was enhanced by rHE4 treatment in vitro. Proteomic analysis revealed activation of focal adhesion kinase signaling in OVCAR8 cells treated with conditioned media from HE4-overexpressing cells. Focal adhesions were increased in cells treated with rHE4 in the presence of fibronectin. These results indicate a direct role for HE4 in mediating malignant properties of ovarian cancer cells and validate the need for HE4-targeted therapies that will suppress activation of oncogenic transcriptional activation and signaling cascades.

Mechanical compression induces VEGFA overexpression in breast cancer via DNMT3A-dependent miR-9 downregulation

Tumor growth generates mechanical compression, which may trigger mechanotransduction in cancer and stromal cells and promote tumor progression. However, very little is known about how compression stimulates signal transduction and contributes to tumor progression. In the present study, we demonstrated that compression enhances a tumor progression phenotype using an in vitro compression model, and validated the results from the in vitro model with high- and low-compressed breast cancer tissues. Mechanical compression induced miR-9 downregulation by DNMT3A-dependent promoter methylation in the MDA-MB-231 and BT-474 breast cancer cell lines and in cancer-associated fibroblasts. The overexpression of miR-9 target genes (LAMC2, ITGA6, and EIF4E) was induced by miR-9 downregulation, which eventually enhanced vascular endothelial growth factors production. Demethylation and decompression could reverse compression-induced miR-9 downregulation and following overexpression of miR-9 target genes and VEGFA.

Stromal Fibroblasts from the Interface Zone of Triple Negative Breast Carcinomas Induced Epithelial-Mesenchymal Transition and its Inhibition by Emodin

“Triple negative breast cancer” (TNBC) is associated with a higher rate and earlier time of recurrence and worse prognosis after recurrence. In this study, we aimed to examine the crosstalk between fibroblasts and TNBC cells. The fibroblasts were isolated from TNBC patients’ tissue in tumor burden zones, distal normal zones and interface zones. The fibroblasts were indicated as cancer-associated fibroblasts (CAFs), normal zone fibroblasts (NFs) and interface zone fibroblasts (INFs). Our study found that INFs grew significantly faster than NFs and CAFs in vitro. The epithelial BT20 cells cultured with the conditioned medium of INFs (INFs-CM) and CAFs (CAFs-CM) showed more spindle-like shape and cell scattering than cultured with the conditioned medium of NFs (NFs-CM). These results indicated that factors secreted by INFs-CM or CAFs-CM could induce the epithelial-mesenchymal transition (EMT) phenotype in BT20 cells. Using an in vitro co-culture model, INFs or CAFs induced EMT and promoted cancer cell migration in BT20 cells. Interestingly, we found that emodin inhibited INFs-CM or CAFs-CM-induced EMT programming and phenotype in BT20 cells. Previous studies reported that CAFs and INFs-secreted TGF-β promoted human breast cancer cell proliferation, here; our results indicated that TGF-β initiated EMT in BT20 cells. Pretreatment with emodin significantly suppressed the TGF-β-induced EMT and cell migration in BT20 cells. These results suggest that emodin may be used as a novel agent for the treatment of TNBC.

Migration of breast cancer cell lines in response to pulmonary laminin 332

Because tumor cell motility is a requirement for metastasis, we hypothesized that lung tissue harbors substances that induce tumor cell migration. MCF-7 breast carcinoma cells exposed to small airway epithelial cells and conditioned medium exhibited dose-dependent tumor cell migration. Among the extracellular matrix proteins in the conditioned medium identified by mass spectrometry, laminin 332 (LM332) had the greatest contribution to the migration of MCF-7 cells. Immunoblotting and immunohistochemistry for LM332-specific chains identified LM332 in the lung and in pulmonary epithelial cells. Antibodies to either LM332 or its integrin receptor inhibited MCF-7 motility, and knockdown of LM332 chains also reduced its migration-inducing activity. Taken together, these findings implicate LM332 as a component of lung tissue that can induce motility in breast carcinoma cells that have been transported to lung during metastasis. Earlier studies on LM332 in tumor progression have examined LM332 expression in tumor cells. This investigation, in comparison, provides evidence that the tumor promoting potential of LM332 may originate in the lung microenvironment rather than in tumor cells alone. Furthermore, this study provides evidence that the motility-inducing properties of the microenvironment can reside in epithelial cells. The findings raise the possibility that LM332 plays a role in the pulmonary metastases of breast carcinoma and may provide a target for antimetastasis therapy.

Nodal metastasis signatures in breast cancer

Although the molecular taxonomy of invasive breast cancer is based on heterogeneous histologic types, pathologic nodal (pN) stage remains one of the most important independent prognostic factors. Although node-positive number (NPN) has been widely as an accepted staging algorithm of pN stage, the node-positive ratio (NPR) in totally resected axillary nodes has been considered as another reasonable indicator. We aimed to identify signatures to play a predictive role in nodal metastasis for analytic validation between the primary breast cancers with positive node metastasis and those with negative node metastasis. We validated expression profiles of surrogate candidates extracted from the prior 2D MALDI-TOF data for invasive breast cancer using fluorescence/silver in situ hybridization (FISH/SISH) and immunohistochemistry (IHC) in 151 primary breast cancers accompanied with 102 metastatic nodal tissues. Cox proportional hazards regression analyses indicated that event factors (recurrence or metastasis) were significantly more frequent in cases with CCDN1, c-myc gene amplification, IgHA2 low expression. CCDN1 gene amplification (OR: 5.702, p=0.0006), IgHA2 low expression (OR: 0.16, p=0.0184) remained significant factors for events on multivariate analyses. WDR⁺/ERK⁺⁺ was significantly detected in higher pN stage (averaging 6.5 regional nodes or 43% of NPR), while seldom found in pN0-1. In conclusion, both overexpression of WDR1 and p-ERK in the primary breast cancer could play a role in the nodal signature over pN2-3.

Surgical margins in head and neck squamous cell carcinoma: Effect of heat artifact on immunohistochemistry as a future tool for assessment

BACKGROUND

Margins in head and neck squamous cell carcinoma (HNSCC) are determined by morphological changes assessed via hematoxylin-eosin staining. Physiological changes may not be detected by this technique. The purpose of this study was to determine if a protein biomarker, laminin-332γ2, overexpressed in cancer cells at the invasive front in HNSCC, remains unaffected by heat produced during resection, supporting a role for immunohistochemistry assessment of margins.

METHODS

Archived tissue blocks from glottic squamous cell carcinomas (SCCs) resected by CO2 laser likely to contain both cancer cells and artifact were identified; 129-paired slides were obtained. One slide of each pair was stained with hematoxylin-eosin; the second stained for laminin-332γ2. The presence of cancer cells, artifact, and positive laminin-332γ2 staining was recorded. Twenty-seven pairs met the inclusion criteria.

RESULTS

Immunohistochemistry staining of laminin-332γ is preserved in presence of heat artifact.

CONCLUSION

This study supports use of immunohistochemistry to assess margins. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1401-1406, 2016.

Normal mammary epithelial cells promote carcinoma basement membrane invasion by inducing microtubule-rich protrusions

Recent work suggests that the dissemination of tumor cells may occur in parallel with, and even preceed, tumor growth. The mechanism for this early invasion is largely unknown. Here, we find that mammary epithelial cells (MECs) induce neighboring breast carcinoma cells (BCCs) to cross the basement membrane by secreting soluble laminin. Laminin continuously produced by MECs induce long membrane cellular protrusions in BCCs that promote their contractility and invasion into the surrounding matrix. These protrusions depend on microtubule bundles assembled de novo through laminin-integrin β1 signaling. These results describe how non-cancerous MECs can actively participate in the invasive process of BCCs.

Prognostic significance of circulating laminin gamma2 for early-stage non-small-cell lung cancer

Background

Laminin gamma2 (Ln-γ2) chain, a distinctive subunit of heterotrimeric laminin-332, is frequently upregulated in carcinomas and is of great importance in cell migration and invasion. Despite this, the status of circulating Ln-γ2 in lung cancer patients is still uncertain.

Patients and methods

In this retrospective study, serum samples from 538 all-stage (stages I–IV) patients with non-small-cell lung cancer (NSCLC) and 94 age-matched healthy volunteers were investigated by enzyme-linked immunosorbent assay. Data were statistically analyzed in combination with clinicopathological information.

Results

Circulating Ln-γ2 was markedly increased in NSCLC, even in stage I cases (P<0.01), reflecting the progression of lung cancer. Survival analysis on 370 eligible patients indicated that serum Ln-γ2-negative patients survived much longer compared with Ln-γ2-positive individuals (P=0.028), and it was especially the case for stage I (P<0.001), stage T1 (P=0.001), and stage N0 patients (P=0.038), all of whom represented early-stage cases. For the advanced patients, however, overall survivals were not significantly different among stages II–IV (P=0.830), stages T2–T4 (P=0.575), stages N1–N3 (P=0.669), and stage M1 (P=0.849). Cox analysis subsequently defined serum Ln-γ2 as an independent prognostic indicator of NSCLC, particularly for early-stage patients. Furthermore, we demonstrated the association of serum Ln-γ2 with smoking behavior, but its association with tumor progression and early prognostic significance were not altered in the nonsmoking cohort.

Conclusion

Our study demonstrated that elevation of circulating Ln-γ2 was an early-emerging event in NSCLC and was significantly associated with poor prognosis in NSCLC, especially for early-stage cases.

The extracellular matrix in breast cancer

The extracellular matrix (ECM) is increasingly recognized as an important regulator in breast cancer. ECM in breast cancer development features numerous changes in composition and organization when compared to the mammary gland under homeostasis. Matrix proteins that are induced in breast cancer include fibrillar collagens, fibronectin, specific laminins and proteoglycans as well as matricellular proteins. Growing evidence suggests that many of these induced ECM proteins play a major functional role in breast cancer progression and metastasis. A number of the induced ECM proteins have moreover been shown to be essential components of metastatic niches, promoting stem/progenitor signaling pathways and metastatic growth. ECM remodeling enzymes are also markedly increased, leading to major changes in the matrix structure and biomechanical properties. Importantly, several ECM components and ECM remodeling enzymes are specifically induced in breast cancer or during tissue regeneration while healthy tissues under homeostasis express exceedingly low levels. This may indicate that ECM and ECM-associated functions may represent promising drug targets against breast cancer, providing important specificity that could be utilized when developing therapies.

The meaning of gross tumor type in the aspects of cytokeratin 19 expression and resection margin in patients with hepatocellular carcinoma

BACKGROUND

There is no consensus on the safe resection margin in patients with hepatocellular carcinoma. Surgeons decide the extent of resection according to residual liver function and tumor location. We investigated the influence of resection margin on early recurrence with respect to gross tumor type and expression of cytokeratin 19 (CK19).

METHODS

We divided the patients into two groups based on the classification of The Korean Liver Cancer Study group as follows: group 1 included expanding and vaguely nodular types whereas group 2 included nodular with perinodular extension, multinodular confluent, and infiltrative types. We classified the resection margin as narrow (0.1-0.9 cm) or wide (greater than 1 cm). We compared clinicopathological features and CK19 positivity between the groups.

RESULTS

Group 2 had a higher prevalence of gross portal vein invasion, microscopic portal vein invasion, microvessel invasion, satellite nodules, intrahepatic metastasis, multicentric occurrence, and positivity for CK19. Group 1 showed no difference in recurrence according to the resection margin; however, group 2 showed a higher recurrence rate in patients with a narrow resection margin compared with those with a wide resection margin (P = 0.047). Patients in group 2 with CK19 positivity showed a higher prevalence of microvessel invasion than those without CK19 (P = 0.026).

CONCLUSIONS

Although our study has the limitation of a small number of cases, the data suggest that patients with hepatocellular carcinoma of expanding and vaguely nodular gross types may safely undergo surgical resection with a narrow resection margin and a low risk of early recurrence.

The extracellular matrix in breast cancer predicts prognosis through composition, splicing, and crosslinking

The extracellular matrix in the healthy breast has an important tumor suppressive role, whereas the abnormal ECM in tumors can promote aggressiveness, and has been linked to breast cancer relapse, survival and resistance to chemotherapy. This review article gives an overview of the elements of the ECM which have been linked to prognosis of breast cancers, including changes in ECM protein composition, splicing, and microstructure.

Galectin-3 Binding Protein Secreted by Breast Cancer Cells Inhibits Monocyte-Derived Fibrocyte Differentiation

To metastasize, tumor cells often need to migrate through a layer of collagen-containing scar tissue which encapsulates the tumor. A key component of scar tissue and fibrosing diseases is the monocyte-derived fibrocyte, a collagen-secreting profibrotic cell. To test the hypothesis that invasive tumor cells may block the formation of the fibrous sheath, we determined whether tumor cells secrete factors that inhibit monocyte-derived fibrocyte differentiation. We found that the human metastatic breast cancer cell line MDA-MB-231 secretes activity that inhibits human monocyte-derived fibrocyte differentiation, whereas less aggressive breast cancer cell lines secrete less of this activity. Purification indicated that Galectin-3 binding protein (LGALS3BP) is the active factor. Recombinant LGALS3BP inhibits monocyte-derived fibrocyte differentiation, and immunodepletion of LGALS3BP from MDA-MB 231 conditioned media removes the monocyte-derived fibrocyte differentiation-inhibiting activity. LGALS3BP inhibits the differentiation of monocyte-derived fibrocytes from wild-type mouse spleen cells, but not from SIGN-R1(-/-) mouse spleen cells, suggesting that CD209/SIGN-R1 is required for the LGALS3BP effect. Galectin-3 and galectin-1, binding partners of LGALS3BP, potentiate monocyte-derived fibrocyte differentiation. In breast cancer biopsies, increased levels of tumor cell-associated LGALS3BP were observed in regions of the tumor that were invading the surrounding stroma. These findings suggest LGALS3BP and galectin-3 as new targets to treat metastatic cancer and fibrosing diseases.

P-cadherin signals through the laminin receptor α6β4 integrin to induce stem cell and invasive properties in basal-like breast cancer cells

P-cadherin is a classical cell-cell adhesion molecule that, in contrast to E-cadherin, has a positive role in breast cancer progression, being considered a poor prognostic factor in this disease. In previous reports, we have shown that this protein induces cancer stem cell and invasive properties to basal-like breast cancer cells. Here, we clarify the downstream signaling pathways that are triggered by P-cadherin to mediate these effects. We demonstrated that P-cadherin inhibition led to a significant decreased adhesion of cancer cells to the basement membrane substrate laminin, as well as to a major reduction in the expression of the laminin receptor α6β4 integrin. Remarkably, the expression of this heterodimer was required for the invasive capacity and increased mammosphere forming efficiency induced by P-cadherin expression. Moreover, we showed that P-cadherin transcriptionally up-regulates the α6 integrin subunit expression and directly interacts with the β4 integrin subunit. We still showed that P-cadherin downstream signaling, in response to laminin, involves the activation of focal adhesion (FAK), Src and AKT kinases. The association between the expression of P-cadherin, α6β4 heterodimer and the active FAK and Src phosphorylated forms was validated in vivo. Our data establish that there is a crosstalk between P-cadherin and the laminin receptor α6β4 integrin signaling pathway, which link has never been previously described. The activation of this heterodimer explains the stem cell and invasive properties induced by P-cadherin to breast cancer cells, pointing to a new molecular mechanism that may be targeted to counteract the effects induced by this adhesion molecule.

Expression of extracellular matrix and cell polarity proteins in tissues at different distances from colorectal cancer lesions

AIM: To investigate the role of cancer micro-environment in colorectal carcinogenesis by detecting the expression of extracellular matrix and cell polarity proteins in tissues at different distances from colorectal cancer lesions.

METHODS: Samples were collected from sites 10, 5, and 2 cm away from colorectal cancer lesions. HE staining was used to observe the structure of crypts. Immunohistochemistry was used to detect the expression of collagen type Ⅰ (Col-Ⅰ), hyaluronidase-1 (Hyal-1), E-cadherin and crumbs3 (CRB3).

RESULTS: As the tissues were getting closer to the colorectal cancer lesions, the expression of Col-Ⅰ and Hyal-1 increased, while that of E-cadherin and CRB3 decreased.

CONCLUSION: Up-regulation of Col-Ⅰ and Hyal-1 and down-regulation of E-cadherin and CRB3 may contribute to the initiation of colorectal cancer.

Role of secreted type I collagen derived from stromal cells in two breast cancer cell lines

Collagen is one of numerous components of the cellular microenvironment. To date, the association between the microenvironment and tumorigenesis of malignant breast cancer remains elusive. Therefore, the aim of the present study was to investigate the potential role of a secretory protein of stromal cells, type I collagen, in the development of the aggressive characteristics of breast cancer cells. MDA-MB231 and MCF7 breast cancer cell lines were maintained in cultured media of normal human dermal fibroblasts (HDFs) and type I collagen-containing media. The morphological changes, adhesion capacity and matrix metalloproteinase (MMP)-1, -2 and -9 mRNA levels were evaluated. The results revealed that cell sprouting and adhesion capacity were enhanced in the MCF7 and MDA-MB231 breast cancer cells in HDF-conditioned culture media as well as in response to type I collagen treatment. The expression of MMP-9 mRNA was high in breast cancer cells cultured with the media of normal HDFs, compared with that of the control media. These data indicate that type I collagen, which is secreted by stromal fibroblasts, may augment the aggressive characteristics of breast cancer cells through the induction of MMP-9 mRNA.

Snail1 induced in breast cancer cells in 3D collagen I gel environment suppresses cortactin and impairs effective invadopodia formation

Although an in vitro 3D environment cannot completely mimic the in vivo tumor site, embedding tumor cells in a 3D extracellular matrix (ECM) allows for the study of cancer cell behaviors and the screening of anti-metastatic reagents with a more in vivo-like context. Here we explored the behaviors of MDA-MB-231 breast cancer cells embedded in 3D collagen I. Diverse tumor environmental conditions (including cell density, extracellular acidity, or hypoxia as mimics for a continuous tumor growth) reduced JNKs, enhanced TGFβ1/Smad signaling activity, induced Snail1, and reduced cortactin expression. The reduced JNKs activity blocked efficient formation of invadopodia labeled with actin, cortactin, or MT1-MMP. JNKs inactivation activated Smad2 and Smad4, which were required for Snail1 expression. Snail1 then repressed cortactin expression, causing reduced invadopodia formation and prominent localization of MT1-MMP at perinuclear regions. MDA-MB-231 cells thus exhibited less efficient collagen I degradation and invasion in 3D collagen I upon JNKs inhibition. These observations support a signaling network among JNKs, Smads, Snail1, and cortactin to regulate the invasion of MDA-MB-231 cells embedded in 3D collagen I, which may be targeted during screening of anti-invasion reagents.

Host matrix modulation by tumor exosomes promotes motility and invasiveness

Exosomes are important intercellular communicators, where tumor exosomes (TEX) severely influence hematopoiesis and premetastatic organ cells. With the extracellular matrix (ECM) being an essential constituent of non-transformed tissues and tumors, we asked whether exosomes from a metastatic rat tumor also affect the organization of the ECM and whether this has consequences on host and tumor cell motility. TEX bind to individual components of the ECM, the preferential partner depending on the exosomes' adhesion molecule profile such that high CD44 expression is accompanied by hyaluronic acid binding and high α6β4 expression by laminin (LN) 332 binding, which findings were confirmed by antibody blocking. TEX can bind to the tumor matrix already during exosome delivery but also come in contact with distinct organ matrices. Being rich in proteases, TEX modulate the ECM as demonstrated for degradation of collagens, LNs, and fibronectin. Matrix degradation by TEX has severe consequences on tumor and host cell adhesion, motility, and invasiveness. By ECM degradation, TEX also promote host cell proliferation and apoptosis resistance. Taken together, the host tissue ECM modulation by TEX is an important factor in the cross talk between a tumor and the host including premetastatic niche preparation and the recruitment of hematopoietic cells. Reorganization of the ECM by exosomes likely also contributes to organogenesis, physiological and pathologic angiogenesis, wound healing, and clotting after vessel disruption.

Loss of TAK1 increases cell traction force in a ROS-dependent manner to drive epithelial-mesenchymal transition of cancer cells

Epithelial–mesenchymal transition (EMT) is a crucial step in tumor progression, and the TGFβ–SMAD signaling pathway as an inductor of EMT in many tumor types is well recognized. However, the role of non-canonical TGFβ–TAK1 signaling in EMT remains unclear. Herein, we show that TAK1 deficiency drives metastatic skin squamous cell carcinoma earlier into EMT that is conditional on the elevated cellular ROS level. The expression of TAK1 is consistently reduced in invasive squamous cell carcinoma biopsies. Tumors derived from TAK1-deficient cells also exhibited pronounced invasive morphology. TAK1-deficient cancer cells adopt a more mesenchymal morphology characterized by higher number of focal adhesions, increase surface expression of integrin α5β1 and active Rac1. Notably, these mutant cells exert an increased cell traction force, an early cellular response during TGFβ1-induced EMT. The mRNA level of ZEB1 and SNAIL, transcription factors associated with mesenchymal phenotype is also upregulated in TAK1-deficient cancer cells compared with control cancer cells. We further show that TAK1 modulates Rac1 and RhoA GTPases activities via a redox-dependent downregulation of RhoA by Rac1, which involves the oxidative modification of low-molecular weight protein tyrosine phosphatase. Importantly, the treatment of TAK1-deficient cancer cells with Y27632, a selective inhibitor of Rho-associated protein kinase and antioxidant N-acetylcysteine augment and hinders EMT, respectively. Our findings suggest that a dysregulated balance in the activation of TGFβ–TAK1 and TGFβ–SMAD pathways is pivotal for TGFβ1-induced EMT. Thus, TAK1 deficiency in metastatic cancer cells increases integrin:Rac-induced ROS, which negatively regulated Rho by LMW-PTP to accelerate EMT.