Evaluation of lumican effects on morphology of invading breast cancer cells, expression of integrins and downstream signaling

Ectopic expression of matrix metalloproteinases and filopodia extension via JNK activation are involved in the invasion of blood tumor cells in Drosophila mxc mutant

Drosophila mxcmbn1 mutant exhibits severe hyperplasia in larval hematopoietic tissue called the lymph glands (LGs). However, the malignant nature of these cells remains unknown. We aimed to identify if mxcmbn1 LG cells behave as malignant tumor cells and uncover the mechanism(s) underlying the malignancy of the mutant hemocytes. When mutant LG cells were allografted into normal adult abdomens, they continued to proliferate; however, normal LG cells did not proliferate. Mutant circulating hemocytes also attached to the larval central nervous system (CNS), where the basement membrane was disrupted. The mutant hemocytes displayed higher expression of matrix metalloproteinase (MMP) 1 and MMP2 and higher activation of the c-Jun N-terminal kinase (JNK) pathway than normal hemocytes. Depletion of MMPs or JNK mRNAs in LGs resulted in reduced numbers of hemocytes attached to the CNS, suggesting that the invasive phenotype involved elevated expression of MMPs via hyperactivation of the JNK pathway. Moreover, hemocytes with elongated filopodia and extra lamellipodia were frequently observed in the mutant hemolymph, which also depended on JNK signaling. Thus, the MMP upregulation and overextension of actin-based cell protrusions were also involved in hemocyte invasion in mxcmbn1 larvae. These findings contribute to the understanding of molecular mechanisms underlying mammalian leukemic invasion.

Small Leucine-Rich Proteoglycan PODNL1 Identified as a Potential Tumor Matrix-Mediated Biomarker for Prognosis and Immunotherapy in a Pan-Cancer Setting

The podocan-like protein 1 (PODNL1), an important member of the small leucine-rich proteoglycans (SLRP) family, is a crucial component of the tumor microenvironment (TME). But its prognostic values and the role in the TME have not been systematically estimated in a pan-cancer setting. Targeting PODNL1, a systematic exploration into the TCGA datasets, reconciling with the analyses of single-cell transcriptomes and immunotherapeutic cohorts in cancers, and validation by tissue microarray-based multiplex immunofluorescence staining was performed. PODNL1 was significantly correlated with the poor prognosis and immunotherapeutic responses in various cancers. In-depth demonstration of molecular mechanisms indicated that PODNL1 expressions were notably positively correlated with cancer-associated fibroblast (CAF) infiltration levels in 33 types of cancers. It also positively correlated with the pan-fibroblast TGF-β response signature score, and the hallmarks including TGF-β, TNF-α, inflammatory response, apical junction, epithelial-mesenchymal transition and hedgehog in pan-cancer. Furthermore, high PODNL1 expressions were positively related with the regulation of tumor-promoting TGF-β signaling through downregulating SMAD2/3:4 heterotrimer regulations transcription and up-regulating the pathway restricted SMAD protein phosphorylation. Single-cell transcriptome analyses and immunofluorescence validations indicated that PODNL1 was predominantly expressed in the cancer cells and CAFs in various cancers. Additionally, the heterogeneity of cancer genotype-phenotype cross-talking was also observed associated with PODNL1. Our systematic study indicates that PODNL1 plays an important role in the complex regulation network of tumor progression, and lays a foundation for further exploration to develop PODNL1 as a valuable matrix-mediated biomarker for cancer immunotherapy and prognosis in a pan-cancer setting.

The Landscape of Small Leucine-Rich Proteoglycan Impact on Cancer Pathogenesis with a Focus on Biglycan and Lumican

Cancer development is a multifactorial procedure that involves changes in the cell microenvironment and specific modulations in cell functions. A tumor microenvironment contains tumor cells, non-malignant cells, blood vessels, cells of the immune system, stromal cells, and the extracellular matrix (ECM). The small leucine-rich proteoglycans (SLRPs) are a family of nineteen proteoglycans, which are ubiquitously expressed among mammalian tissues and especially abundant in the ECM. SLRPs are divided into five canonical classes (classes I-III, containing fourteen members) and non-canonical classes (classes IV-V, including five members) based on their amino-acid structural sequence, chromosomal organization, and functional properties. Variations in both the protein core structure and glycosylation status lead to SLRP-specific interactions with cell membrane receptors, cytokines, growth factors, and structural ECM molecules. SLRPs have been implicated in the regulation of cancer growth, motility, and invasion, as well as in cancer-associated inflammation and autophagy, highlighting their crucial role in the processes of carcinogenesis. Except for the class I SLRP decorin, to which an anti-tumorigenic role has been attributed, other SLPRs' roles have not been fully clarified. This review will focus on the functions of the class I and II SLRP members biglycan and lumican, which are correlated to various aspects of cancer development.

Monitoring of breast cancer progression via aptamer-based detection of circulating tumor cells in clinical blood samples

Introduction: Breast cancer (BC) diagnostics lack noninvasive methods and procedures for screening and monitoring disease dynamics. Admitted CellSearch^® is used for fluid biopsy and capture of circulating tumor cells of only epithelial origin. Here we describe an RNA aptamer (MDA231) for detecting BC cells in clinical samples, including blood. The MDA231 aptamer was originally selected against triple-negative breast cancer cell line MDA-MB-231 using cell-SELEX. Methods: The aptamer structure in solution was predicted using mFold program and molecular dynamic simulations. The affinity and specificity of the evolved aptamers were evaluated by flow cytometry and laser scanning microscopy on clinical tissues from breast cancer patients. CTCs were isolated form the patients' blood using the developed method of aptamer-based magnetic separation. Breast cancer origin of CTCs was confirmed by cytological, RT-qPCR and Immunocytochemical analyses. Results: MDA231 can specifically recognize breast cancer cells in surgically resected tissues from patients with different molecular subtypes: triple-negative, Luminal A, and Luminal B, but not in benign tumors, lung cancer, glial tumor and healthy epithelial from lungs and breast. This RNA aptamer can identify cancer cells in complex cellular environments, including tumor biopsies (e.g., tumor tissues vs. margins) and clinical blood samples (e.g., circulating tumor cells). Breast cancer origin of the aptamer-based magnetically separated CTCs has been proved by immunocytochemistry and mammaglobin mRNA expression. Discussion: We suggest a simple, minimally-invasive breast cancer diagnostic method based on non-epithelial MDA231 aptamer-specific magnetic isolation of circulating tumor cells. Isolated cells are intact and can be utilized for molecular diagnostics purposes.

Proteoglycans in breast cancer, identification and characterization by LC-MS/MS assisted proteomics approach: A review

PURPOSE

Proteoglycans (PGs) are negatively charged macromolecules containing a core protein and single or several glycosaminoglycan chains attached by covalent bond. They are distributed in all tissues, including extracellular matrix (ECM), cell surface, and basement membrane. They are involved in major pathways and cell signalling cascades which modulate several vital physiological functions of the body. They have also emerged as a target molecule for cancer treatment and as possible biomarkers for early cancer detection. Among cancers, breast cancer is a highly invasive and heterogenous type and has become the major cause of mortality especially among women. So, this review revisits the studies on PGs characterization in breast cancer using LC-MS/MS-based proteomics approach, which will be further helpful for identification of potential PGs-based biomarkers or therapeutic targets.

EXPERIMENTAL DESIGN

There is a lack of comprehensive knowledge on the use of LC-MS/MS-based proteomics approaches to identify and characterize PGs in breast cancer.

RESULTS

LC-MS/MS assisted PGs characterization in breast cancer revealed the vital PGs in breast cancer invasion and progression. In addition, comprehensive profiling and characterization of PGs in breast cancer are efficiently carried out by this approach.

CONCLUSIONS

Proteomics techniques including LC-MS/MS-based identification of proteoglycans is effectively carried out in breast cancer research. Identification of expression at different stages of breast cancer is a major challenge, and LC-MS/MS-based profiling of PGs can boost novel strategies to treat breast cancer, which involve targeting PGs, and also aid early diagnosis using PGs as biomarkers.

The Novel SLRP Family Member Lumican Suppresses Pancreatic Cancer Cell Growth

OBJECTIVES

The past studies clearly indicated that lumican was important in the context of pancreatic cancer (PC) onset and progression, but failed to clarify the underlying mechanistic basis for such activity. As such, we evaluated the functional importance of lumican in the context of pancreatic ductal adenocarcinoma (PDAC) to understand its mechanistic role in PC.

METHODS

Lumican levels were evaluated in PDAC patient tissues via quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemistry approaches. The role of lumican was additionally assessed via transfecting PDAC cell lines (BxPC-3, PANC-1) with lumican knockdown or overexpression constructs and treating PDAC cell lines with exogenous recombinant human lumican.

RESULTS

Lumican expression levels were significantly higher in pancreatic tumor tissues relative to healthy paracancerous tissues. Lumican knockdown in BxPC-3 and PANC-1 enhanced their proliferation and migration, but reduced cellular apoptosis. Alternatively, lumican overexpression and exogenous lumican exposure failed to alter the proliferative activity of these cells. Further, lumican knockdown in BxPC-3 and PANC-1 cells results in marked P53 and P21 dysregulation.

CONCLUSIONS

Lumican may suppress PDAC tumor growth by regulating P53 and P21, and the function of lumican sugar chains in the context of PC is worth studying in future studies.

Proteoglycans Determine the Dynamic Landscape of EMT and Cancer Cell Stemness

Proteoglycans (PGs) are pivotal components of extracellular matrices, involved in a variety of processes such as migration, invasion, morphogenesis, differentiation, drug resistance, and epithelial-to-mesenchymal transition (EMT). Cellular plasticity is a crucial intermediate phenotypic state acquired by cancer cells, which can modulate EMT and the generation of cancer stem cells (CSCs). PGs affect cell plasticity, stemness, and EMT, altering the cellular shape and functions. PGs control these functions, either by direct activation of signaling cascades, acting as co-receptors, or through regulation of the availability of biological compounds such as growth factors and cytokines. Differential expression of microRNAs is also associated with the expression of PGs and their interplay is implicated in the fine tuning of cancer cell phenotype and potential. This review summarizes the involvement of PGs in the regulation of EMT and stemness of cancer cells and highlights the molecular mechanisms.

The Anticancer Effect of a Novel Quinoline Derivative 91b1 through Downregulation of Lumican

Quinoline derivatives have been reported to possess a wide range of pharmaceutical activities. Our group previously synthesized a series of quinoline compounds, in which compound 91b1 showed a significant anticancer effect. The purpose of this study was to evaluate the anticancer activity of compound 91b1 in vitro and in vivo, and screen out its regulated target. A series of cancer cell lines and nontumor cell lines were treated with compound 91b1 by MTS cytotoxicity assay and cell-cycle assay. In vivo anticancer activity was evaluated by a xenografted model on nude mice. Target prediction of 91b1 was assessed by microarray assay and confirmed by pancancer analysis. Relative expression of the target gene Lumican was measured by qRT-PCR. 91b1 significantly reduced tumor size in the nude mice xenograft model. Lumican was downregulated after 91b1 treatment. Lumican was proven to increase tumorigenesis in vivo, as well as cancer cell migration, invasion, and proliferation in vitro. The results of this study suggest that the anticancer activity of compound 91b1 probably works through downregulating the gene Lumican.

The microRNA-cell surface proteoglycan axis in cancer progression

Proteoglycans consist one of the major extracellular matrix class of biomolecules that demonstrate nodal roles in cancer progression. Μodern diagnostic and therapeutic approaches include proteoglycan detection and pharmacological targeting in various cancers. Proteoglycans orchestrate critical signaling pathways for cancer development and progression through dynamic interactions with matrix components. It is well established that the epigenetic signatures of cancer cells play critical role in guiding their functional properties and metastatic potential. Secreted microRNAs (miRNAs) reside in a complex network with matrix proteoglycans, thus affecting cell-cell and cell-matrix communication. This mini-review aims to highlight current knowledge on the proteoglycan-mediated signaling cascades that regulate miRNA biogenesis in cancer. Moreover, the miRNA-mediated proteoglycan regulation during cancer progression and mechanistic aspects on the way that proteoglycans affect miRNA expression are presented. Recent advances on the role of cell surface proteoglycans in exosome biogenesis and miRNA packaging and expression are also discussed.

Higher Expression of SPP1 Predicts Poorer Survival Outcomes in Head and Neck Cancer

Secreted phosphoprotein 1 (SPP1) participated in various biological processes in many cancers, including immune response, tumor progression, and prognosis. However, SPP1 in head and neck squamous cell carcinoma (HNSCC) remains unknown. Clinical-genetic data of HNSCC were obtained from The Cancer Genome Atlas (TCGA) database. The differential expression of SPP1 in HNSCC tissues and adjacent normal tissues was quantified by bioinformatics methods and verified by western blot and other differential biological methods. We concluded that SPP1 is significantly upregulated in tumor tissues and can become a prognostic biomarker for HNSCC.

Extracellular matrix guidance of autophagy: a mechanism regulating cancer growth

The extracellular matrix (ECM) exists as a dynamic network of biophysical and biochemical factors that maintain tissue homeostasis. Given its sensitivity to changes in the intra- and extracellular space, the plasticity of the ECM can be pathological in driving disease through aberrant matrix remodelling. In particular, cancer uses the matrix for its proliferation, angiogenesis, cellular reprogramming and metastatic spread. An emerging field of matrix biology focuses on proteoglycans that regulate autophagy, an intracellular process that plays both critical and contextual roles in cancer. Here, we review the most prominent autophagic modulators from the matrix and the current understanding of the cellular pathways and signalling cascades that mechanistically drive their autophagic function. We then critically assess how their autophagic functions influence tumorigenesis, emphasizing the complexities and stage-dependent nature of this relationship in cancer. We highlight novel emerging data on immunoglobulin-containing and proline-rich receptor-1, heparanase and thrombospondin 1 in autophagy and cancer. Finally, we further discuss the pro- and anti-autophagic modulators originating from the ECM, as well as how these proteoglycans and other matrix constituents specifically influence cancer progression.

Lumican in Carcinogenesis-Revisited

Carcinogenesis is a multifactorial process with the input and interactions of environmental, genetic, and metabolic factors. During cancer development, a significant remodeling of the extracellular matrix (ECM) is evident. Proteoglycans (PGs), such as lumican, are glycosylated proteins that participate in the formation of the ECM and are established biological mediators. Notably, lumican is involved in cellular processes associated with tumorigeneses, such as EMT (epithelial-to-mesenchymal transition), cellular proliferation, migration, invasion, and adhesion. Furthermore, lumican is expressed in various cancer tissues and is reported to have a positive or negative correlation with tumor progression. This review focuses on significant advances achieved regardingthe role of lumican in the tumor biology. Here, the effects of lumican on cancer cell growth, invasion, motility, and metastasis are discussed, as well as the repercussions on autophagy and apoptosis. Finally, in light of the available data, novel roles for lumican as a cancer prognosis marker, chemoresistance regulator, and cancer therapy target are proposed.

Syndecan-4 in Tumor Cell Motility

Simple Summary

Cell migration is crucial fReaor metastasis formation and a hallmark of malignancy. The primary cause of high mortality among oncology patients is the ability of cancer cells to metastasize. To form metastasis, primary tumor cells must be intrinsically able to move. The transmembrane, heparan sulfate proteoglycan syndecan-4 (SDC4) exhibits multiple functions in signal transduction by regulating Rac1 GTPase activity and consequently actin remodeling, as well as regulating focal adhesion kinase, protein kinase C-alpha and the level of intracellular calcium. By affecting several signaling pathways and biological processes, SDC4 is involved in cell migration under physiological and pathological conditions as well. In this review, we discuss the SDC4-mediated cell migration focusing on the role of SDC4 in tumor cell movement.

Abstract

Syndecan-4 (SDC4) is a ubiquitously expressed, transmembrane proteoglycan bearing heparan sulfate chains. SDC4 is involved in numerous inside-out and outside-in signaling processes, such as binding and sequestration of growth factors and extracellular matrix components, regulation of the activity of the small GTPase Rac1, protein kinase C-alpha, the level of intracellular calcium, or the phosphorylation of focal adhesion kinase. The ability of this proteoglycan to link the extracellular matrix and actin cytoskeleton enables SDC4 to contribute to biological functions like cell adhesion and migration, cell proliferation, cytokinesis, cellular polarity, or mechanotransduction. The multiple roles of SDC4 in tumor pathogenesis and progression has already been demonstrated; therefore, the expression and signaling of SDC4 was investigated in several tumor types. SDC4 influences tumor progression by regulating cell proliferation as well as cell migration by affecting cell-matrix adhesion and several signaling pathways. Here, we summarize the general role of SDC4 in cell migration and tumor cell motility.

A functional outside-in signaling network of proteoglycans and matrix molecules regulating autophagy

Proteoglycans and selected extracellular matrix constituents are emerging as intrinsic and critical regulators of evolutionarily conversed, intracellular catabolic pathways. Often, these secreted molecules evoke sustained autophagy in a variety of cell types, tissues, and model systems. The unique properties of proteoglycans have ushered in a paradigmatic shift to broaden our understanding of matrix-mediated signaling cascades. The dynamic cellular pathway controlling autophagy is now linked to an equally dynamic and fluid signaling network embedded in a complex meshwork of matrix molecules. A rapidly emerging field of research encompasses multiple matrix-derived candidates, representing a menagerie of soluble matrix constituents including decorin, biglycan, endorepellin, endostatin, collagen VI and plasminogen kringle 5. These matrix constituents are pro-autophagic and simultaneously anti-angiogenic. In contrast, perlecan, laminin α2 chain, and lumican have anti-autophagic functions. Mechanistically, each matrix constituent linked to intracellular catabolic events engages a specific cell surface receptor that often converges on a common core of the autophagic machinery including AMPK, Peg3 and Beclin 1. We consider this matrix-evoked autophagy as non-canonical given that it occurs in an allosteric manner and is independent of nutrient availability or prevailing bioenergetics control. We propose that matrix-regulated autophagy is an important outside-in signaling mechanism for proper tissue homeostasis that could be therapeutically leveraged to combat a variety of diseases.

Factors Associated with Promoted Proliferation of Osteosarcoma by Peptidylarginine Deiminase 4

Osteosarcoma is the most common type of bone malignancy, and the pathogenesis has not been entirely elucidated yet. An important deimination modification enzyme PADI4 (peptidylarginine deiminase 4) has attracted much attention in recent years for its important function in several kinds of human tumors. However, the role of PADI4 on osteosarcoma tumorigenesis remains largely unrevealed. Here, we first assessed the effect of PADI4 on osteosarcoma proliferation by the CCK8 method and colony formation assay. Ectopically expressing PADI4 positively regulates the colony formation capacity of both U2OS and Saos-2 cells. Furthermore, we explored the related mechanism and showed that PADI4 could stimulate Wnt/β-catenin and MEK/ERK signaling in both U2OS and Saos-2 cells. Then, we detected expression of PADI4 in human tissues of osteosarcoma and revealed that differential expression of PADI4 was associated with tumorigenesis of osteosarcoma. Last, we performed the in vivo experiment in nude mice and results also showed PADI4 could affect the tumor growth. In conclusion, this work revealed that PADI4 could upregulate the proliferation of osteosarcoma, mainly via the Wnt/β-catenin and MEK/ERK signaling pathway. This study gives us new insight into the regulation mechanism of osteosarcoma proliferation and highlights PADI4 as a promising target for osteosarcoma diagnosis and treatment.

A guide to the composition and functions of the extracellular matrix

Extracellular matrix (ECM) is a dynamic 3-dimensional network of macromolecules that provides structural support for the cells and tissues. Accumulated knowledge clearly demonstrated over the last decade that ECM plays key regulatory roles since it orchestrates cell signaling, functions, properties and morphology. Extracellularly secreted as well as cell-bound factors are among the major members of the ECM family. Proteins/glycoproteins, such as collagens, elastin, laminins and tenascins, proteoglycans and glycosaminoglycans, hyaluronan, and their cell receptors such as CD44 and integrins, responsible for cell adhesion, comprise a well-organized functional network with significant roles in health and disease. On the other hand, enzymes such as matrix metalloproteinases and specific glycosidases including heparanase and hyaluronidases contribute to matrix remodeling and affect human health. Several cell processes and functions, among them cell proliferation and survival, migration, differentiation, autophagy, angiogenesis, and immunity regulation are affected by certain matrix components. Structural alterations have been also well associated with disease progression. This guide on the composition and functions of the ECM gives a broad overview of the matrisome, the major ECM macromolecules, and their interaction networks within the ECM and with the cell surface, summarizes their main structural features and their roles in tissue organization and cell functions, and emphasizes the importance of specific ECM constituents in disease development and progression as well as the advances in molecular targeting of ECM to design new therapeutic strategies.

Profiling the expression of pro-metastatic genes in association with the clinicopathological features of primary breast cancer

BACKGROUND

Metastasis accounts for ninety percent of breast cancer (BrCa) mortality. Cortactin, Ras homologous gene family member A (RhoA), and Rho-associated kinase (ROCK) raise cellular motility in favor of metastasis. Claudins (CLDN) belong to tight junction integrity and are dysregulated in BrCa. Thus far, epidemiologic evidence regarding the association of different pro-metastatic genes with pathological phenotypes of BrCa is largely inconsistent. This study aimed to determine the possible transcriptional models of pro-metastatic genes incorporate in holding the integrity of epithelial cell-cell junctions (CTTN, RhoA, ROCK, CLDN-1, CLDN-2, and CLDN-4), for the first time, in association with clinicopathological features of primary BrCa.

METHODS

In a consecutive case-series design, 206 newly diagnosed non-metastatic eligible BrCa patients with histopathological confirmation (30-65 years) were recruited in Tabriz, Iran (2015-2017). Real-time RT-PCR was used. Then fold changes in the expression of target genes were measured.

RESULTS

ROCK amplification was associated with the involvement of axillary lymph node metastasis (ALNM; ORadj. = 3.05, 95%CI 1.01-9.18). Consistently, inter-correlations of CTTN-ROCK (β = 0.226, P < 0.05) and RhoA-ROCK (β = 0.311, P < 0.01) were determined among patients diagnosed with ALNM+ BrCa. In addition, the overexpression of CLDN-4 was frequently observed in tumors identified by ALNM+ or grade III (P < 0.05). The overexpression of CTTN, CLDN-1, and CLDN-4 genes was correlated positively with the extent of tumor size. CTTN overexpression was associated with the increased chance of luminal-A positivity vs. non-luminal-A (ORadj. = 1.96, 95%CI 1.02-3.77). ROCK was also expressed in luminal-B BrCa tumors (P < 0.05). The estrogen receptor-dependent transcriptions were extended to the inter-correlations of RhoA-ROCK (β = 0.280, P < 0.01), ROCK-CLDN-2 (β = 0.267, P < 0.05), and CLDN-1-CLDN-4 (β = 0.451, P < 0.001).

CONCLUSIONS

For the first time, our findings suggested that the inter-correlations of CTTN-ROCK and RhoA-ROCK were significant transcriptional profiles determined in association with ALNM involvement; therefore the overexpression of ROCK may serve as a potential molecular marker for lymphatic metastasis. The provided binary transcriptional profiles need more approvals in different clinical features of BrCa metastasis.

Lumican, pro-tumorigenic or anti-tumorigenic: A conundrum

The extracellular matrix (ECM) consists of a myriad of structural and signaling molecules which potentially regulate cell function and homeostasis. Lumican, a class II SLRP (small leucine rich proteoglycan) is a ubiquitous ECM component which not only organizes the collagen based structural matrix, but also modulates cell proliferation signals as observed in cancer. In the perspective of cancer biology, lumican expression in the tumor microenvironment is associated with signaling, which can result in either pro-tumorigenic or anti-tumorigenic effects. Its pro-tumorigenic effects are mainly observed in gastric, bladder and liver cancers, which is associated with deterioration of clinical prognosis. Lumican mediated pro-tumorigenic effects involve activation of focal adhesion kinases (FAK), mitogen activated protein kinases (MAPK) and metalloproteinase-9 (MMP-9). On the contrary, in breast cancer, pancreatic cancer and melanoma, lumican demonstrates anti-tumorigenic effects, which are associated with favorable clinical outcomes. Anti-tumorigenic potential of lumican is clubbed with epithelial-mesenchymal transition reprogramming as well as downregulation of extracellular signal-regulated kinases (ERK), FAK and MMP-14 mediated pathways thereby preventing tumorigenesis. This review highlights that the expressional significance of lumican in cancer biogenesis is tumor specific and demands rigorous cancer-specific evaluation to understand its role as a potential anti-cancer target or a therapeutic molecule.

Communications via the Small Leucine-rich Proteoglycans: Molecular Specificity in Inflammation and Autoimmune Diseases

Inflammation is a highly regulated biological response of the immune system that is triggered by assaulting pathogens or endogenous alarmins. It is now well established that some soluble extracellular matrix constituents, such as small leucine-rich proteoglycans (SLRPs), can act as danger signals and trigger aseptic inflammation by interacting with innate immune receptors. SLRP inflammatory signaling cascade goes far beyond its canonical function. By choosing specific innate immune receptors, coreceptors, and adaptor molecules, SLRPs promote a switch between pro- and anti-inflammatory signaling, thereby determining disease resolution or chronification. Moreover, by orchestrating signaling through various receptors, SLRPs fine-tune inflammation and, despite their structural homology, regulate inflammatory processes in a molecule-specific manner. Hence, the overarching theme of this review is to highlight the molecular and functional specificity of biglycan-, decorin-, lumican-, and fibromodulin-mediated signaling in inflammatory and autoimmune diseases.

Three-Dimensional Models as a New Frontier for Studying the Role of Proteoglycans in the Normal and Malignant Breast Microenvironment

The extracellular matrix (ECM) provides cues to direct mammogenesis, tumourigenesis and metastatic processes. Over the past several decades, two-dimensional (2D) culture models have been invaluable in furthering our understanding of the tumor microenvironment (TME), however, they still do not accurately emulate the associated biological complexities. In contrast, three-dimensional (3D) culture models provide a more physiologically relevant platform to study relevant physicochemical signals, stromal-epithelial cell interactions, vascular and immune components, and cell-ECM interactions in the human breast microenvironment. A common thread that may weave these multiple interactions are the proteoglycans (PGs), a prominent family of molecules in breast tissue. This review will discuss how these PGs contribute to the breast cancer TME and provide a summary of the traditional and emerging technologies that have been utilized to better understand the role of PGs during malignant transformation. Furthermore, this review will emphasize the differences that PGs exhibit between normal tissues and tumor ECM, providing a rationale for the investigation of underexplored roles of PGs in breast cancer progression using state-of-the-art 3D culture models.

Preparation of RGD4C fused anti-TNFα nanobody and inhibitory activity on triple-negative breast cancer in vivo

AIMS

Triple-negative breast cancer (TNBC) is not sensitive to current endocrine treatments, so new treatment strategies need to be explored. Based on previous antitumour studies on anti-TNFα nanobody, we designed a novel fusion nanobody to enhance antitumour activity of the anti-TNFα nanobody in TNBC.

MAIN METHODS

The RGD4C contains RGD sequence, which is the smallest recognition unit binding to the αvβ3 receptor on tumour cell membranes and involved in tumour cell adhesion, proliferation, and metastasis. RGD4C was fused to anti-TNFα nanobody to investigate the antitumour activity in vitro and in vivo.

KEY FINDINGS

The antitumour effects of fusion nanobody V-L-R-H could effectively bind to αvβ3 and inhibit cell migration and proliferation of MDA-MB-231, which had satisfying purification efficiency and approving antigen or receptor binding activity. V-L-R-H could inhibit the TNFα-mediated PI3K/AKT/NF-κB signal pathway and integrin αvβ3 correlative FAK focal adhesion signal pathway. Mouse xenograft tumour experiments showed that the V-L-R-H could inhibit tumour proliferation and metastasis; reduce the TNFα, HIFα, Ki67, and CD31 concentrations in tumour; and inhibit the process of epithelial-mesenchymal transition.

SIGNIFICANCE

The fusion nanobody enhanced antitumour activity of the anti-TNFα nanobody on TNBC. It provided a reference for the design of dual functional fusion proteins and development of tumour treatment strategies of antagonistic TNFα and αvβ3, and a new therapeutic strategy and research direction for the treatment of TNBC.

Label-Free Infrared Spectral Histology of Skin Tissue Part II: Impact of a Lumican-Derived Peptide on Melanoma Growth

Melanoma is the most aggressive type of cutaneous malignancies. In addition to its role as a regulator of extracellular matrix (ECM) integrity, lumican, a small leucine-rich proteoglycan, also exhibits anti-tumor properties in melanoma. This work focuses on the use of infrared spectral imaging (IRSI) and histopathology (IRSH) to study the effect of lumican-derived peptide (L9Mc) on B16F1 melanoma primary tumor growth. Female C57BL/6 mice were injected with B16F1 cells treated with L9Mc (n = 10) or its scrambled peptide (n = 8), and without peptide (control, n = 9). The melanoma primary tumors were subjected to histological and IR imaging analysis. In addition, immunohistochemical staining was performed using anti-Ki-67 and anti-cleaved caspase-3 antibodies. The IR images were analyzed by common K-means clustering to obtain high-contrast IRSH that allowed identifying different ECM tissue regions from the epidermis to the tumor area, which correlated well with H&E staining. Furthermore, IRSH showed good correlation with immunostaining data obtained with anti-Ki-67 and anti-cleaved caspase-3 antibodies, whereby the L9Mc peptide inhibited cell proliferation and increased strongly apoptosis of B16F1 cells in this mouse model of melanoma primary tumors.