Publications by authors named "George N Tzanakakis"

Increased hyaluronan deposition (HA) in various cancer tissues, including sarcomas, correlates with disease progression. The receptor for hyaluronic acid-mediated motility (RHAMM) expression is elevated in most human cancers. β-catenin is a critical downstream mediator of the Wnt signaling pathways, facilitating carcinogenic events characterized by deregulated cell proliferation.

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Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), referred to as keratinocyte carcinomas, are skin cancer with the highest incidence. BCCs, rarely metastasize; whereas, though generally not characterized by high lethality, approximately 2-4% of primary cSCCs metastasize with patients exhibiting poor prognosis. The extracellular matrix (ECM) serves as a scaffold that provides structural and biological support to cells in all human tissues.

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Osteosarcoma (OS) is a mesenchymally derived, aggressive bone cancer. OS cells produce an aberrant nonmineralized or partly mineralized extracellular matrix (ECM) whose components participate in signaling pathways connected to specific pathogenic phenotypes of this bone cancer. The expression of biglycan (BGN), a secreted small leucine-rich proteoglycan (SLRP), is correlated to aggressive OS phenotype and resistance to chemotherapy.

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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.

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Bone sarcomas, mesenchymal origin tumors, represent a substantial group of varying neoplasms of a distinct entity. Bone sarcoma patients show a limited response or do not respond to chemotherapy. Notably, developing efficient chemotherapy approaches, dealing with chemoresistance, and preventing metastasis pose unmet challenges in sarcoma therapy.

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The tumor microenvironment (TME) is composed of cancerous, non-cancerous, stromal, and immune cells that are surrounded by the components of the extracellular matrix (ECM). Glycosaminoglycans (GAGs), natural biomacromolecules, essential ECM, and cell membrane components are extensively altered in cancer tissues. During disease progression, the GAG fine structure changes in a manner associated with disease evolution.

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Nanoparticles (NPs) produced from amphiphilic derivatives of poly--vinylpyrrolidone (Amph-PVP), composed of various molecular weight polymeric hydrophilic fragments linked into hydrophobic -alkyl chains of varying lengths, were previously shown to exert excellent biocompatibility. Although routes of administration can be different, finally, most nanosystems enter the blood circulation or lymphatic vessels, and by this, they establish direct contact with endothelial cells. In this study, Amph-PVP NPs and fluorescently labeled Amph-PVP-based NPs, namely "PVP" NPs (Amph-PVP-NPs (6000 Da) unloaded) and "F"-NPs (Amph-PVP-NPs (6000 Da) loaded with fluorescent FITC), were synthesized to study Amph-PVP NPs interactions with HMEC-1 endothelial cells.

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Chondrosarcoma is a malignant bone tumor characterized by the production of a modified cartilage‑type extracellular matrix (ECM). In the present study, the expression levels of the small leucine‑rich proteoglycans (SLRPs), decorin, biglycan and lumican, were examined in the HTB94 human chondrosarcoma cell line. HTB94 cells were found to express and secrete the 3 SLRP members.

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Allergic contact dermatitis (ACD) is caused by topical exposure to chemical allergens. Keratinocytes play a key role in innate immunity, as well as in ACD progression. The transmembrane Toll-like receptor 4 (TLR4), strongly implicated in skin inflammation, has the ability to bind Damage Associated Molecular Patterns (DAMPs), like Low Molecular Weight Hyaluronan (LMWHA).

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Biglycan, a small leucine rich proteoglycan (SLRP), is an important participant in bone homeostasis and development as well as in bone pathology. In the present study biglycan was identified as a positive regulator of MG63 osteosarcoma cell growth ( ≤ 0.001).

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During the past few years, considerable evidence has uncovered a strong relationship between fat and bone metabolism. Consequently, alterations in plasma lipid metabolic pathways strongly affect bone mass and quality. We recently showed that the deficiency of apolipoprotein A-1 (APOA1), a central regulator of high-density lipoprotein cholesterol (HDL-C) metabolism, results in reduced bone mass in C57BL/6 mice.

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Proteoglycans (PGs), important constituents of the extracellular matrix, have been associated with cancer pathogenesis. Their unique structure consisting of a protein core and glycosaminoglycan chains endowed with fine modifications constitutes these molecules as capable cellular effectors important for homeostasis and contributing to disease progression. Indeed, differential expression of PGs and their interacting proteins has been characterized as specific for disease evolvement in various cancer types.

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Fibrosarcoma is a tumor of mesenchymal origin, originating from fibroblasts. IGF-I is an anabolic growth factor which exhibits significant involvement in cancer progression. In this study, we investigated the possible participation of syndecan-2 (SDC-2), a cell membrane heparan sulfate (HS) proteoglycan on IGF-I dependent fibrosarcoma cell motility.

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Syndecan 2 (SDC2) belongs to a four-member family of evolutionary conserved small type I transmembrane proteoglycans consisting of a protein core to which glycosaminoglycan chains are covalently attached. SDC2 is a cell surface heparan sulfate proteoglycan, which is increasingly drawing attention for its distinct characteristics and its participation in numerous cell functions, including those related to carcinogenesis. Increasing evidence suggests that the role of SDC2 in cancer pathogenesis is dependent on cancer tissue origin rendering its use as a biomarker/therapeutic target feasible.

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Soft tissue sarcomas are rare, heterogeneous tumors of mesenchymal origin with an aggressive behavior. Heparin is a mixture of heavily sulfated, linear glycosaminoglycan (GAG) chains, which participate in the regulation of various cell biological functions. Heparin is considered to have significant anticancer capabilities, although the mechanisms involved have not been fully defined.

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In this data article, the potential role of p53 tumor suppressor gene (p53) on the attachment ability of MCF-7 breast cancer cells was investigated. In our main article, "IGF-I/ EGF and E2 signaling crosstalk through IGF-IR conduit point affect breast cancer cell adhesion" (K. Voudouri, D.

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We studied the feasibility of using a short-term culture of monocytes, isolated from peripheral donor blood, to assess the biological activity of different types of bionanomaterials (BNM): biodegradable polimeric particles, fiber and film substrates of micro- and nano-dimensions, fullerenes (F) and nanodiamonds (ND), which are either currently in use and/or potentially applicable in medicine. Additionally, the effect of creating a protein corona on ND and F particles was investigated. The cellular reduction of (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) is a well-established tool for assessing the viability/metabolic activity of cells.

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Osteosarcoma (OS) is a primary bone tumor of mesenchymal origin mostly affecting children and adolescents. The OS extracellular matrix (ECM) is extensively altered as compared to physiological bone tissue. Indeed, the main characteristic of the most common osteoblastic subtype of OS is non‑mineralized osteoid production.

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Epidermal growth factor (EGF)/insulin like growth factor-I (IGF-I) and Estradiol (E2) can regulate biological functions of hormone-dependent tumor cells. Fibronectin (FN) is a large glycoprotein abundantly expressed in breast cancer extracellular matrices (ECMs) postulated to be a marker of aggressiveness during cancer pathogenesis. In this study we demonstrate that IGF-I/EGF as well E2 strongly increase the adhesion of the MCF-7 breast cancer cells onto FN.

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Regression in melanoma is a frequent biological event of uncertain prognostic value as the lesion exhibits heterogeneous phenotypical features, both at the morphological and immunohistochemical level. In the present study, we examined the expression of tissue inhibitors of metalloproteinases (TIMP1, TIMP2 and TIMP3) in melanoma with regression. We specifically examined the expression levels of these TIMPs in regressed components (RC) and non-regressed components (NRC) of the tumor and compared their expression levels with those in non-regressed melanomas.

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Background: High levels of hyaluronan (HA) synthesis in various cancer tissues, including sarcomas, are correlated with tumorigenesis and malignant transformation. RHAMM (receptor for hyaluronic acid-mediated motility) is overexpressed during tumor development in different malignancies. β-Catenin is a crucial downstream mediator of the Wnt signaling cascade which facilitates carcinogenic events characterized by deregulated cell proliferation.

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Background: Facial anthropometric analysis is essential for planning cosmetic and reconstructive facial surgery, but has not been available in detail for modern Greeks. In this study, multiple measurements of the face were performed on young Greek males and females to provide a complete facial anthropometric profile of this population and to compare its facial morphology with that of North American Caucasians.

Materials And Methods: Thirty-one direct facial anthropometric measurements were obtained from 152 Greek students.

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Background: Hyaluronan (HA), a glycosaminoglycan, is a key extracellular matrix (ECM) component, and has been established to contribute to fibrotic, angiogenic, inflammatory as well as processes supporting cancer development. The changes in HA deposition in different tumors have been widely studied. Indeed, a multitude of reports demonstrate that HA expression is increased in different neoplasmatic tissues including lung, colon, prostate and breast cancer.

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Breast cancer is the most common type of cancer for women worldwide with a lifetime risk amounting to a staggering total of 10%. It is well established that the endogenous synthesis of insulin-like growth factor (IGF) and epidermal growth factor (EGF) polypeptide growth factors are closely correlated to malignant transformation and all the steps of the breast cancer metastatic cascade. Numerous studies have demonstrated that both estrogens and growth factors stimulate the proliferation of steroid-dependent tumor cells, and that the interaction between these signaling pathways occurs at several levels.

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The role of inflammation in the development of cancer was described as early as the nineteenth century. Abundant evidence supports the preposition that various cancers are triggered by infection and chronic inflammatory disease whereas, evading immune destruction has been proposed as one of the new "hallmarks of cancer." Changes of the tumor microenvironment have been closely correlated to cancer-mediated inflammation.

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