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Simple Summary: Cancers and metabolic diseases represent a leading cause of death in both developing and developed countries. Thus, new diagnostic and prognostic targets are urgently required. NEU-1 is a sialidase which regulates many membrane receptors through desialylation which results in either the activation or inhibition of the receptors. At the plasma membrane, NEU-1 is the catalytic subunit of the elastin receptor complex. This sialidase is not only required for the biological effects that are mediated by the elastin-derived peptides on several metabolic disorders, but NEU-1 is also involved in the development of various cancers. The aim of this review is to describe the role of NEU-1 in several metabolic diseases and cancers and to show that this protein could be considered in some cases as a link between these two physiopathological contexts. Consequently, NEU-1 could represent a common pharmacological target to treat putative metabolic syndrome-associated cancers like colorectal, hepatocellular and postmenopausal breast cancer. Sialidases or neuraminidases (NEU) are glycosidases which cleave terminal sialic acid residues from glycoproteins, glycolipids and oligosaccharides. Four types of mammalian sialidases, which are encoded by different genes, have been described with distinct substrate specificity and subcellular localization: NEU-1, NEU-2, NEU-3 and NEU-4. Among them, NEU-1 regulates many membrane receptors through desialylation which results in either the activation or inhibition of these receptors. At the plasma membrane, NEU-1 also associates with the elastin-binding protein and the carboxypeptidase protective protein/cathepsin A to form the elastin receptor complex. The activation of NEU-1 is required for elastogenesis and signal transduction through this receptor, and this is responsible for the biological effects that are mediated by the elastin-derived peptides (EDP) on obesity, insulin resistance and non-alcoholic fatty liver diseases. Furthermore, NEU-1 expression is upregulated in hepatocellular cancer at the mRNA and protein levels in patients, and this sialidase regulates the hepatocellular cancer cells' proliferation and migration. The implication of NEU-1 in other cancer types has also been shown notably in the development of pancreatic carcinoma and breast cancer. Altogether, these data indicate that NEU-1 plays a key role not only in metabolic disorders, but also in the development of several cancers which make NEU-1 a pharmacological target of high potential in these physiopathological contexts. [ABSTRACT FROM AUTHOR]

We report the synthesis of new series of heterocyclic systems eugenol 1 derivatives by the mixed condensation reaction of 1,3-dipolar azide and the oxide of p-chlorophenylnitrile on the 4-allyl-2-methoxy-1-(prop-2-yn-1-yloxy)benzene 2. The mono and bicycloadducts, whose structure is homologous to compounds having a broad spectrum of activity, were obtained in good yields. The monocondensation reaction of azides on 4-allyl-2-methoxy-1-(prop-2-yn-1-yloxy)benzene 2 is completely chemoselective, regioselective and stereospecific. The condensation of nitrile oxide on 1,2,3-triazole monocycloadducts prepared was chemoselective and regioselective. The structure of all cycloadducts were characterized and confirmed by the 1H, 13C, 2D nuclear magnetic resonance and mass spectrometry analysis. All the newly synthesized mono and bis-heterocyclic compounds have been selected for their antiproliferative activity against HT-1080 fibrosarcoma, A549 lung carcinoma, and MCF-7 and MDA-MB-231 breast carcinoma cell lines. Among the derivatives, only the compounds 4a, 4b, 5a, 5b, 5d, 5e and 5g showed significant cytotoxicity with IC50 values ranging from 15.31 to 18.81 µM against HT-1080 cells, and 17.32 to 25.94 µM against the other cell lines. [ABSTRACT FROM AUTHOR]

The extracellular matrix critically controls cancer cell behavior by inducing several signaling pathways through cell membrane receptors. Besides conferring structural properties to tissues around the tumor, the extracellular matrix is able to regulate cell proliferation, survival, migration, and invasion. Among these receptors, the integrins family constitutes a major class of receptors that mediate cell interactions with extracellular matrix components. Twenty years ago, a new class of extracellular matrix receptors has been discovered. These tyrosine kinase receptors are the two discoidin domain receptors DDR1 and DDR2. DDR1 was first identified in the Dictyostelium discoideum and was shown to mediate cell aggregation. DDR2 shares highly conserved sequences with DDR1. Both receptors are activated upon binding to collagen, one of the most abundant proteins in extracellular matrix. While DDR2 can only be activated by fibrillar collagen, particularly types I and III, DDR1 is mostly activated by type I and IV collagens. In contrast with classical growth factor tyrosine kinase receptors which display a rapid and transient activation, DDR1 and DDR2 are unique in that they exhibit delayed and sustained receptor phosphorylation upon binding to collagen. Recent studies have reported differential expression and mutations of DDR1 and DDR2 in several cancer types and indicate clearly that these receptors have to be taken into account as new players in the different aspects of tumor progression, from non-malignant to highly malignant and invasive stages. This review will discuss the current knowledge on the role of DDR1 and DDR2 in malignant transformation, cell proliferation, epithelial to mesenchymal transition, migratory, and invasive processes, and finally the modulation of the response to chemotherapy. These new insights suggest that DDR1 and DDR2 are new potential targets in cancer therapy. [ABSTRACT FROM AUTHOR]

Abstract: Our previous studies have shown that camptothecin and doxorubicin triggered ceramide accumulation via de novo synthesis pathway. De novo ceramide generation was responsible for the drug-induced apoptosis through a caspase-3-dependent pathway and a decrease of thrombospondin-1 expression in human thyroid carcinoma FTC-133 cells. Here, we demonstrate that Jun N-terminal kinases play a critical role in camptothecin- and doxorubicin-induced down-regulation of thrombospondin-1 expression: i) de novo ceramide synthesis pathway activates Jun N-terminal kinase 1/2 resulting in activating transcription factor 2 phosphorylation; ii) cell treatment by SP600125, a Jun N-terminal kinase specific inhibitor, strongly reduced activating transcription factor 2 phosphorylation and completely abolished camptothecin and doxorubicin effects; and iii) activating transcription factor 2 expression silencing greatly attenuated camptothecin- and doxorubicin-induced down-regulation of thrombospondin-1 expression and apoptosis. The set of our data established that camptothecin- and doxorubicin-induced activation of Jun N-terminal kinase/activating transcription factor 2 pathway via de novo ceramide synthesis down-regulates thrombospondin-1 expression and apoptosis in human thyroid carcinoma FTC-133 cells. This article is part of a Special Issue entitled: 11th European Symposium on Calcium. [Copyright &y& Elsevier]

Simple Summary: Proteolytic enzymes, such as matrix metalloproteinases, plasminogen activators and cathepsins, as well as non-proteolytic enzymatic partners, such as heparanase and hyaluron-idases, play key roles in the propagation and metastatic potential of cancer cells. This article aims to revisit the main functions of major matrix remodeling molecules and their effects in cancer meta-static potential. Moreover, the epigenetic regulation mechanisms of these molecules are discussed, in addition to recent advances in their pharmacological targeting. Finally, novel data from ongoing clinical trials on several cancer types are also provided. Overall, this review delves into the im-portance of matrix remodeling partners in cancer metastasis and explores their targeting as a promising therapeutic option for cancer management. Tissue functionality and integrity demand continuous changes in distribution of major components in the extracellular matrices (ECMs) under normal conditions aiming tissue homeostasis. Major matrix degrading proteolytic enzymes are matrix metalloproteinases (MMPs), plasminogen activators, atypical proteases such as intracellular cathepsins and glycolytic enzymes including heparanase and hyaluronidases. Matrix proteases evoke epithelial-to-mesenchymal transition (EMT) and regulate ECM turnover under normal procedures as well as cancer cell phenotype, motility, invasion, autophagy, angiogenesis and exosome formation through vital signaling cascades. ECM remodeling is also achieved by glycolytic enzymes that are essential for cancer cell survival, proliferation and tumor progression. In this article, the types of major matrix remodeling enzymes, their effects in cancer initiation, propagation and progression as well as their pharmacological targeting and ongoing clinical trials are presented and critically discussed. [ABSTRACT FROM AUTHOR]

Abstract: Doxorubicin and camptothecin are two cytotoxic chemotherapeutic agents triggering apoptosis in various cancer cells, including thyroid carcinoma cells. Recent studies revealed a critical role of ceramide in chemotherapy and suggested that anti-cancer drugs may kill tumor cells through sphingomyelinase activation. However, in comparison to sphingomyelin hydrolysis, the relative involvement of de novo ceramide synthesis remained poorly explored and highly controversial. Here, we evidenced that both doxorubicin and camptothecin triggered ceramide accumulation in thyroid carcinoma cells. We demonstrated that ceramide increase occurred via the de novo pathway without neither acidic nor neutral sphingomyelinase contribution. Interestingly, de novo ceramide generation was responsible for the drug-induced malignant cell apoptosis through a caspase-3-dependent pathway and a decrease of thrombospondin amount. Furthermore, blocking ceramide metabolism by inhibiting glucosylceramide synthase strengthened the camptothecin and doxorubicin-dependent effects. Altogether, we evidenced that de novo ceramide synthesis mediates the anti-tumor properties of doxorubicin and camptothecin in thyroid carcinoma and suggested that glucosylation of ceramide may contribute to the drug-resistance phenotype in thyroid malignancies. [Copyright &y& Elsevier]