Anaplastic thyroid cancers (ATC) are aggressive tumors, which exhibit cell cycle misregulations leading to uncontrolled cellular proliferation and genomic instability. They fail to respond to chemotherapeutic agents and radiation therapy, and most patients die within a few months of diagnosis. In the present study, we evaluated the in vitro effects on ATC cells of VX-680, an inhibitor of the Aurora serine/threonine kinases involved in the regulation of multiple aspects of chromosome segregation and cytokinesis.
View Article and Find Full Text PDFAurora-A kinase has recently been shown to be deregulated in thyroid cancer cells and tissues. Among the Aurora-A substrates identified, transforming acidic coiled-coil (TACC3), a member of the TACC family, plays an important role in cell cycle progression and alterations of its expression occur in different cancer tissues. In this study, we demonstrated the expression of the TACC3 gene in normal human thyroid cells (HTU5), and its modulation at both mRNA and protein levels during cell cycle.
View Article and Find Full Text PDFOncocytic tumors are a distinctive class of proliferative lesions composed of cells with a striking degree of mitochondrial hyperplasia that are particularly frequent in the thyroid gland. To understand whether specific mitochondrial DNA (mtDNA) mutations are associated with the accumulation of mitochondria, we sequenced the entire mtDNA in 50 oncocytic lesions (45 thyroid tumors of epithelial cell derivation and 5 mitochondrion-rich breast tumors) and 52 control cases (21 nononcocytic thyroid tumors, 15 breast carcinomas, and 16 gliomas) by using recently developed technology that allows specific and reliable amplification of the whole mtDNA with quick mutation scanning. Thirteen oncocytic lesions (26%) presented disruptive mutations (nonsense or frameshift), whereas only two samples (3.
View Article and Find Full Text PDFThe Aurora kinases are involved in the regulation of cell cycle progression, and alterations in their expression have been shown to associate with cell malignant transformation. In the present study, we demonstrated that human thyrocytes express all 3 Aurora kinases (A, B and C) at both protein and mRNA level and this expression is cell cycle-regulated. An increase in the protein level of the 3 kinases was found, with respect to normal human thyrocytes (HTU5), in the human cell lines derived from follicular (FTC-133), papillary (B-CPAP) and anaplastic (8305C) thyroid carcinomas, but not in cells derived from a follicular adenoma (HTU42).
View Article and Find Full Text PDFThe study of cellular differentiation encompasses many vital parts of biology and medicine. Heparan sulfate proteoglycans (HSPG) are essential and ubiquitous macromolecules associated with the cell surface and extracellular matrix (ECM) of a wide range of cells and tissues. Heparan sulfate chains (HS) of HSPG bind and sequester a multitude of extracellular ligands, including growth factors, cytokines, chemokines, enzymes, and lipoproteins.
View Article and Find Full Text PDFProgrammed cell death is characterized by posttranslational modifications of a limited and specific set of nuclear proteins. We demonstrate that during apoptosis of different types of tumor cells there is a monomethylation of the nuclear protein HMGA1a that is associated to its previously described hyperphosphorylation/dephosphorylation process. HMGA1a methylation is strictly related to the execution of programmed cell death and is a massive event that involves large amounts of the protein.
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