Matrix proteoglycans are markedly affected in advanced laryngeal squamous cell carcinoma

AbstractProteoglycans (PGs) are implicated in the growth and progression of malignant tumors. In this study, we examined the concentration and localization of PGs in advanced (stage IV) laryngeal squamous cell carcinoma (LSCC) and compared with human normal larynx (HNL). LSCC and HNL sections were examined immunohistochemically with a panel of antibodies, and tissues extracts were analyzed by biochemical methods including immunoblotting and high performance liquid chromatography (HPLC). The results demonstrated significant destruction of cartilage in LSCC, which was followed by marked decrease of aggrecan and link protein. In contrast to the loss of aggrecan in LSCC, accumulation of versican and decorin was observed in the tumor-associated stroma. Biochemical analyses indicated that aggrecan, versican, decorin and biglycan comprise the vast majority of total PGs in both healthy and cancerous tissue. In LSCC the absolute amounts of KS/CS/DS-containing PGs were dramatically decreased about 18-fold in comparison to HNL. This decrease is due to the loss of aggrecan. Disaccharide analysis of CS/DSPGs from LSCC showed a significant reduction of 6-sulfated Δ-disaccharides (Δdi-6S) with a parallel increase of 4-sulfated Δ-disaccharides (Δdi-4S) as compared to HNL. The obtained data clearly demonstrate that tumor progression is closely related to specific alteration of matrix PGs in LSCC. The altered composition of PGs in cartilage, as well as in tumor-associated stroma, is crucial for the biological behaviour of cancer cells in the diseased tissue

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

IGF-IR cooperates with ERα to inhibit breast cancer cell aggressiveness by regulating the expression and localisation of ECM molecules

IGF-IR is highly associated with the behaviour of breast cancer cells. In ERα-positive breast cancer, IGF-IR is present at high levels. In clinical practice, prolonged treatment with anti-estrogen agents results in resistance to the therapy with activation of alternative signaling pathways. Receptor Tyrosine Kinases, and especially IGF-IR, have crucial roles in these processes. Here, we report a nodal role of IGF-IR in the regulation of ERα-positive breast cancer cell aggressiveness and the regulation of expression levels of several extracellular matrix molecules. In particular, activation of IGF-IR, but not EGFR, in MCF-7 breast cancer cells results in the reduction of specific matrix metalloproteinases and their inhibitors. In contrast, IGF-IR inhibition leads to the depletion by endocytosis of syndecan-4. Global important changes in cell adhesion receptors, which include integrins and syndecan-4 triggered by IGF-IR inhibition, regulate adhesion and invasion. Cell function assays that were performed in MCF-7 cells as well as their ERα-suppressed counterparts indicate that ER status is a major determinant of IGF-IR regulatory role on cell adhesion and invasion. The strong inhibitory role of IGF-IR on breast cancer cells aggressiveness for which E2-ERα signaling pathway seems to be essential, highlights IGF-IR as a major molecular target for novel therapeutic strategies

Versican but not decorin accumulation is related to malignancy in mammographically detected high density and malignant-appearing microcalcifications in non-palpable breast carcinomas

<p>Abstract</p> <p>Background</p> <p>Mammographic density (MD) and malignant-appearing microcalcifications (MAMCs) represent the earliest mammographic findings of non-palpable breast carcinomas. Matrix proteoglycans versican and decorin are frequently over-expressed in various malignancies and are differently involved in the progression of cancer. In the present study, we have evaluated the expression of versican and decorin in non-palpable breast carcinomas and their association with high risk mammographic findings and tumor characteristics.</p> <p>Methods</p> <p>Three hundred and ten patients with non-palpable suspicious breast lesions, detected during screening mammography, were studied. Histological examination was carried out and the expression of decorin, versican, estrogen receptor α (ERα), progesterone receptor (PR) and c-erbB2 (HER-2/neu) was assessed by immunohistochemistry.</p> <p>Results</p> <p>Histological examination showed 83 out of 310 (26.8%) carcinomas of various subtypes. Immunohistochemistry was carried out in 62/83 carcinomas. Decorin was accumulated in breast tissues with MD and MAMCs independently of the presence of malignancy. In contrast, versican was significantly increased only in carcinomas with MAMCs (median ± SE: 42.0 ± 9.1) and MD (22.5 ± 10.1) as compared to normal breast tissue with MAMCs (14.0 ± 5.8), MD (11.0 ± 4.4) and normal breast tissue without mammographic findings (10.0 ± 2.0). Elevated levels of versican were correlated with higher tumor grade and invasiveness in carcinomas with MD and MAMCs, whereas increased amounts of decorin were associated with <it>in situ </it>carcinomas in MAMCs. Stromal deposition of both proteoglycans was related to higher expression of ERα and PR in tumor cells only in MAMCs.</p> <p>Conclusions</p> <p>The specific accumulation of versican in breast tissue with high MD and MAMCs only in the presence of malignant transformation and its association with the aggressiveness of the tumor suggests its possible use as molecular marker in non-palpable breast carcinomas.</p

Extracellular matrix structure.

Extracellular matrix (ECM) is a non-cellular three-dimensional macromolecular network composed of collagens, proteoglycans/glycosaminoglycans, elastin, fibronectin, laminins, and several other glycoproteins. Matrix components bind each other as well as cell to adhesion receptors forming a complex network into which cells reside in all tissues and organs. Cell surface receptors transduce signals into cells from ECM, which regulate diverse cellular functions, such as survival, growth, migration, and differentiation and are vital for maintaining normal homeostasis. ECM is a highly dynamic structural network that continuously undergoes remodeling mediated by several matrix-degrading enzymes during normal and pathological conditions. Deregulation of ECM composition and structure is associated with the development and progression of several pathologic conditions. This article emphasizes in the complex ECM structure as to provide a better understanding of its dynamic structural and functional multipotency. Where relevant, the implication of the various families of ECM macromolecules in health and disease is also presented

Syndecans as modulators and potential pharmacological targets in cancer progression

Extracellular matrix (ECM) components form a dynamic network of key importance for cell function and properties. Key macromolecules in this interplay are syndecans (SDCs), a family of transmembrane heparan sulfate proteoglycans (HSPGs). Specifically, heparan sulfate (HS) chains with their different sulfation pattern have the ability to interact with growth factors and their receptors in tumor microenvironment, promoting the activation of different signaling cascades that regulate tumor cell behavior. The affinity of HS chains with ligands is altered during malignant conditions because of the modification of chain sequence/sulfation pattern. Furthermore, matrix degradation enzymes derived from the tumor itself or the tumor microenvironment, like heparanase and matrix metalloproteinases (MMPs), ADAM as well as ADΑMTS are involved in the cleavage of SDCs ectodomain at the HS and protein core level, respectively. Such released soluble syndecans shed syndecans in the extracellular matrix interact in an autocrine or paracrine manner with the tumor or/and stromal cells. Shed syndecans, upon binding to several matrix effectors, such as growth factors, chemokines and cytokines, have the ability to act as competitive inhibitors for membrane PGs, and modulate the inflammatory microenvironment of cancer cells. It is notable that syndecans and their soluble counterparts may affect either the behavior of cancer cells and/or their microenvironment during cancer progression. The importance of these molecules has been highlighted since HSPGs have been proposed as prognostic markers of solid tumors and hematopoietic malignancies. Going a step further down the line, the multi-actions of syndecans in many levels make them appealing as potential pharmacological targets, either by targeting directly the tumor or indirectly the adjacent stroma

Estrogen receptor beta modulates breast cancer cells functional properties, signaling and expression of matrix molecules

Estrogen receptors have pivotal roles in breast cancer growth and progression. ER\u3b1 has been clearly shown to play key role in hormone-dependent breast cancer properties, but little is known for the isoform ER\u3b2. To evaluate the role of ER\u3b2, we established stably transfected ER\u3b2-suppressed MDA-MB-231 breast cancer cells by knocking down the human ER\u3b2 gene, using specific shRNA lentiviral particles. As observed by scanning electron microscopy, the ER\u3b2 suppression induces significant phenotypic changes in these cells, as compared to the control cells. Notably, the down-regulation of ER\u3b2 decreases the expression of the mesenchymal markers fibronectin and vimentin, whereas it increases the expression levels of the epithelial marker E-cadherin and cell junctions. These alterations are followed by reduced levels of the functional cell properties that promote the aggressiveness of these cells, such as proliferation, migration, spreading capacity, invasion and adhesion on collagen I. Notably, the down-regulation of ER\u3b2 reduces the migration of breast cancer cells through the tyrosine kinase receptors EGFR/IGF-IR and the JAK/STAT signaling pathways. Moreover, ER\u3b2 has a crucial role on the gene expression of several matrix mediators, including the proteoglycans syndecans-2/-4 and serglycin, several matrix metalloproteinases, plasminogen activation system components and receptor tyrosine kinases. These data clearly show that ER\u3b2 plays a crucial role in the cell behavior and ECM composition of the highly aggressive MDA-MB-231 cells and opens a new area of research to further understand its role and to improve pharmaceutical targeting of the non-hormone dependent breast cancer

Serglycin inhibits the classical and lectin pathways of complement via its glycosaminoglycan chains: Implications for multiple myeloma

Serglycin (SG) is a proteoglycan expressed by hematopoietic cells and is constitutively secreted by multiple myeloma (MM) cells. SG participates in the regulation of various inflammatory events. We found that SG secreted by human MM cell lines inhibits both the classical and lectin pathways of complement, without influencing alternative pathway activity. The inhibitory effect of SG is due to direct interactions with C1q and mannose-binding lectin (MBL). C1q-binding is mediated through the glycosaminoglycan moieties of SG, whereas MBL binds additionally to SG protein core. Interactions between SG and C1q as well as MBL are diminished in the presence of chondroitin sulfate type E. In addition, we localized the SG-binding site to the collagen-like stalk of C1q. Interactions between SG and C1q as well as MBL are ionic in character and only the interaction with MBL was found to be partially dependent on the presence of calcium. We found the serum levels of SG to be elevated in patients with MM compared to healthy controls. Moreover, we found that SG expressed from myeloma plasma cells protects these cells from complement activation induced by treatment with anti-thymocyte immunoglobulins. This might protect myeloma cells during immunotherapy and promote survival of malignant cells