u-0126 and Chondrosarcoma

Osteoarthritis (OA) is a degenerative disease characterized by progressive articular cartilage destruction and joint marginal osteophyte formation with different degrees of synovitis. Docosahexaenoic acid (DHA) is an unsaturated fatty acid with anti-inflammatory, antioxidant, and antiapoptotic functions. In this study, the human chondrosarcoma cell line SW1353 was cultured in vitro, and an OA cell model was constructed with inflammatory factor IL-1β stimulation. After cells were treated with DHA, cell apoptosis was measured. Western blot assay was used to detect protein expression of apoptosis-related factors (Bax, Bcl-2, and cleaved caspase-3) and mitogen-activated protein kinase (MAPK) signaling pathway family members, including extracellular signal-regulated kinase (ERK), c-JUN N-terminal kinase (JNK), and p38 MAPK. Our results show that IL-1β promotes the apoptosis of SW1353 cells, increases the expression of Bax and cleaved caspase-3, and activates the MAPK signaling pathway. In contrast, DHA inhibits the expression of IL-1β, inhibits IL-1β-induced cell apoptosis, and has a certain inhibitory effect on the activation of the MAPK signaling pathway. When the MAPK signaling pathway is inhibited by its inhibitors, the effects of DHA on SW1353 cells are weakened. Thus, DHA enhances the apoptosis of SW1353 cells through the MAPK signaling pathway.

Topics: Apoptosis; Apoptosis Regulatory Proteins; Bone Neoplasms; Butadienes; Cell Line, Tumor; Chondrosarcoma; Docosahexaenoic Acids; Drug Evaluation, Preclinical; Enzyme Activation; Enzyme Induction; Gene Expression Regulation, Neoplastic; Humans; Interleukin-1beta; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases; Neoplasm Proteins; Nitriles; Osteoarthritis; Protein Kinase Inhibitors

Cysteine-rich 61 (Cyr61), from the CCN gene family, is a secreted and matrix-associated protein, which is involved in many cellular activities such as growth and differentiation. However, the effect of Cyr61 on migration activity in human chondrosarcoma cells is mostly unknown. Here, we found that Cyr61 increased the migration and expression of matrix metalloproteinase (MMP)-13 in human chondrosarcoma cells (JJ012 cells). RGD peptide, alphavbeta3 monoclonal antibody and mitogen-activated protein kinase (MEK) inhibitors (PD98059 and U0126) but not RAD peptide inhibited the Cyr61-induced increase of the migration and MMP-13 upregulation of chondrosarcoma cells. Cyr61 stimulation increased the phosphorylation of focal adhesion kinase (FAK) and extracellular signal-regulated kinase (ERK). In addition, activator protein-1 (AP-1) decoy oligodeoxynucleotide also suppressed the MMP-13 messenger RNA and enzyme activity enhanced by Cyr61. Moreover, Cyr61 increased the binding of c-Fos and c-Jun to the AP-1 element on the MMP-13 promoter. Taken together, our results indicated that Cyr61 enhances the migration of chondrosarcoma cells by increasing MMP-13 expression through the alphavbeta3 integrin receptor, FAK, ERK, c-Fos/c-Jun and AP-1 signal transduction pathway.

Topics: Bone Neoplasms; Butadienes; Cell Line, Tumor; Cell Movement; Chondrosarcoma; Cysteine-Rich Protein 61; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Focal Adhesion Protein-Tyrosine Kinases; Humans; Integrin alphaVbeta3; Matrix Metalloproteinase 13; Nitriles; Oligopeptides; Signal Transduction; Transcription Factor AP-1

Our laboratory showed that bikunin, a Kunitz-type protease inhibitor, suppresses 4beta-phorbol 12-myristate 13-acetate (PMA)- or tumor necrosis factor-alpha (TNFalpha)-induced urokinase-type plasminogen activator (uPA) expression in different cell types. In addition to its effects on protease inhibition, bikunin could be modulating other cellular events associated with the metastatic cascade. To test this hypothesis, we examined whether bikunin was able to suppress the expression of uPA receptor (uPAR) mRNA and protein in a human chondrosarcoma cell line, HCS-2/8, and two human ovarian cancer cell lines, HOC-I and HRA. The present study showed that (a) bikunin suppresses the expression of constitutive and PMA-induced uPAR mRNA and protein in a variety of cell types; (b) an extracellular signal-regulated kinase (ERK) activation system is necessary for the PMA-induced increase in uPAR expression, as PD098059 and U0126, which prevent the activation of MEK1, reduce the uPAR expression; (c) bikunin markedly suppresses PMA-induced phosphorylation of ERK1/2 at the concentration that prevents uPAR expression, but does not reduce total ERK1/2 antigen level; (d) bikunin has no ability to inhibit overexpression of uPAR in cells treated with sodium vanadate; and (e) we further studied the inhibition of uPAR expression by stable transfection of HRA cells with bikunin gene, demonstrating that bikunin secretion is necessary for inhibition of uPAR expression. We conclude that bikunin downregulates constitutive and PMA-stimulated uPAR mRNA and protein possibly through suppression of upstream targets of the ERK-dependent cascade, independent of whether cells were treated with exogenous bikunin or transfected with bikunin gene.

Topics: Bone Neoplasms; Butadienes; Carcinoma; Chondrosarcoma; Depression, Chemical; Enzyme Activation; Enzyme Inhibitors; Female; Flavonoids; Gene Expression Regulation; Gene Expression Regulation, Neoplastic; Humans; MAP Kinase Kinase 1; MAP Kinase Signaling System; Membrane Glycoproteins; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinase Kinases; Mitogen-Activated Protein Kinases; Neoplasm Proteins; Nitriles; Ovarian Neoplasms; Phosphorylation; Protein Processing, Post-Translational; Protein Serine-Threonine Kinases; Receptors, Cell Surface; Receptors, Urokinase Plasminogen Activator; Recombinant Fusion Proteins; RNA, Messenger; Tetradecanoylphorbol Acetate; Transfection; Trypsin Inhibitor, Kunitz Soybean; Tumor Cells, Cultured