stilbenes and Chondrosarcoma

Chondrosarcoma is the second most common primary bone sarcoma. Treatment of chondrosarcoma is limited to surgery due to radiation and chemotherapy resistance of this cancer. An ideal treatment for chondrosarcoma would be a well-tolerated, minimally invasive local or systemic treatment modality to halt or slow tumor growth prior to resection of local, unresectable local, or metastatic disease. Palovarotene, an agonist of nuclear retinoic acid receptor γ (RARγ) has shown therapeutic action for treatment of heterotopic ossification and osteochondroma without serious adverse effects in animal models. We hypothesized that selective agonists of RARγ would have an inhibitory effect on chondrosarcoma. All human chondrosarcoma specimens expressed RARγ as determined by immunohistochemical staining. The ΗCS-2/8 chondrosarcoma cell line, established from low-grade human chondrosarcoma, was used to examine the actions of RARγ agonists. In ΗCS2/8 pellet cultures, RARγ agonist treatment reduced the mass size and significantly decreased total glycosaminoglycan, protein amounts, and gene expression levels of cartilage matrix molecules when compared with control groups. Systemic treatment with RARγ agonists significantly inhibited the growth of ΗCS-2/8 cell transplants in vivo. Furthermore, local injection of RARγ agonist-loaded poly-lactic acid nanoparticles induced regression of the mass size of the transplants. Histologic analysis demonstrated that RARγ agonist treatment inhibited cell proliferation activity and stimulated encapsulation of the tumor. These findings indicate that RARγ agonists, including palovarotene, may have an anti-tumor effect on low-grade chondrosarcomas. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1045-1051, 2020.

Topics: Animals; Bone Neoplasms; Cell Line, Tumor; Chondrosarcoma; Humans; Mice; Pyrazoles; Receptors, Retinoic Acid; Retinoic Acid Receptor gamma; Stilbenes; Xenograft Model Antitumor Assays

Topics: Animals; Cell Line, Tumor; Chondrosarcoma; Female; Male; Mice; Mice, Nude; Primary Cell Culture; Rats, Sprague-Dawley; Stilbenes; Xenograft Model Antitumor Assays

The present study assessed the mechanism by which resveratrol (Res) inhibits the growth of SW1353 chondrosarcoma cells and examined whether sirtuin 1 (Sirt1) activation affects phosphorylation within the signal transduction and activator of transcription 3 (STAT3) signaling pathway. The present study used SW1353 chondrosarcoma cells in the logarithmic phase of growth (control and treatment groups). The latter group was treated with Res at 25 and 50 µmol/l for 24 h, and cell viability, proliferation and apoptosis were analyzed using the cell counting kit‑8 assay, colony counting and Hoechst staining, respectively. The expression levels of caspase‑3, cleaved caspase‑3, B‑cell lymphoma‑2 (BCL‑2), BCL-2 associated X protein (Bax), STAT3 and phosphorylated (p‑)STAT3) were measured by Western blotting. SW1353 cells were transfected with small interfering (si)RNA targeting Sirt1 and the expression levels of Sirt1, STAT3 and p-STAT3 were assessed. Exposure of SW1353 cells to Res reduced cell viability in a dose‑dependent manner (P<0.01). Additionally, cell proliferation was significantly inhibited and the cell nuclei exhibited apoptotic characteristics. Cleaved caspase‑3, Sirt1 and Bax levels were upregulated. The expression levels of BCL‑2 and p‑STAT3 were downregulated. Additionally, the BCL‑2/Bax ratio was reduced compared with the control group. The total STAT3 level was unaffected. Res treatment activated Sirt1, however, in cells transfected with Sirt1‑siRNA, the ability of resveratrol to suppress p‑STAT3 expression was compromised. Overall, it was revealed that Res treatment induced apoptosis, inhibited proliferation and affected phosphorylation within the STAT3 signaling pathway by activating Sirt1 in SW1353 chondrosarcoma cells.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; bcl-2-Associated X Protein; Bone Neoplasms; Caspase 3; Cell Line, Tumor; Cell Proliferation; Cell Survival; Chondrosarcoma; Dose-Response Relationship, Drug; Humans; Phosphorylation; Proto-Oncogene Proteins c-bcl-2; Resveratrol; Signal Transduction; Sirtuin 1; STAT3 Transcription Factor; Stilbenes

Resveratrol has been shown to possess anticancer, anti-aging, and anti-inflammatory properties. Matrix metalloproteinases (MMPs) appear to be responsible for much of the extracellular matrix (ECM) degradation observed in the progression of cancer, aging and inflammation. We found that resveratrol significantly inhibited MMP-2 and MMP-9, and induced the expression of type II collagen and sex-determining region Y-box (SOX)-9 and the production of sulfated proteoglycans in HTB94 chondrosarcoma cells. Moreover, inhibition of MMPs with an MMP inhibitor further enhanced the effects of resveratrol. Phosphorylation of p38 was increased and phosphorylation of c-Jun N-terminal kinase (JNK) was inhibited by resveratrol. Treatment with SB203580, a p38 kinase inhibitor, enhanced the suppression of MMP-2 and MMP-9 by resveratrol and inhibited resveratrol-induced stimulation of type II collagen and SOX-9 expression and production of sulfated proteoglycans. Treatment with SP600125, a JNK inhibitor, attenuated the effects of resveratrol on MMP-2 and MMP-9, and accelerated resveratrol-induced effects on type II collagen, SOX-9 and sulfated proteoglycan production. Our results suggest that resveratrol inhibits MMP-induced differentiation via the p38 kinase and JNK pathways in HTB94 chondrosarcoma cells.

Topics: Anthracenes; Antineoplastic Agents, Phytogenic; Bone Neoplasms; Cell Differentiation; Cell Line, Tumor; Chondrosarcoma; Gene Expression Regulation, Neoplastic; Humans; Imidazoles; MAP Kinase Signaling System; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Pyridines; Resveratrol; Stilbenes

The natural phytoestrogen resveratrol (RSV) may have therapeutic potential for arthritic conditions. RSV is chondroprotective for articular cartilage in rabbit models for arthritis, but its biological effects on human articular cartilage and chondrosarcoma cells are unknown. Effects of RSV on human articular cartilage homeostasis were studied by assessing production of matrix-degrading enzymes (MMP-13, ADAMTS4, and ADAMTS5), as well as proteoglycan production and synthesis. The counteractions of RSV against catabolic factors (e.g., FGF-2 or IL-1β) were examined by in vitro and ex vivo using monolayer, three-dimensional alginate beads and cartilage explants cultures, respectively. RSV improves cell viability of articular chondrocytes and effectively antagonizes cartilage-degrading protease production that was initiated by catabolic and/or anti-anabolic cytokines in human articular chondrocytes. RSV significantly also enhances BMP7-promoted proteoglycan synthesis as assessed by (35) S-sulfate incorporation. Protein-DNA interaction arrays suggest that RSV inhibits the activation of transcription factors involved in inflammation and cartilage catabolic signaling pathways, including direct downstream regulators of MAPK (e.g., AP-1, PEA3) and NFκB. RSV selectively compromises survival of human chondrosarcoma cells, but not primary articular chondrocytes, revealing cell-specific activity of RSV on non-tumorigenic versus tumor-derived cells. We propose that RSV exerts its chondroprotective functions, in part, by deactivating p53-induced apoptosis in human primary chondrocytes, but not human chondrosarcoma. Our findings suggest that RSV has potential as a unique biologic treatment for both prevention and treatment of cartilage degenerative diseases.

Topics: Apoptosis; Bone Morphogenetic Protein 7; Bone Neoplasms; Cartilage, Articular; Cell Line, Tumor; Chondrocytes; Chondrosarcoma; Cytokines; DNA-Binding Proteins; Extracellular Signal-Regulated MAP Kinases; Humans; Inflammation; Interleukin-1beta; Metabolism; Oncogene Protein v-akt; Peptide Hydrolases; Plants; Polyphenols; Proteasome Endopeptidase Complex; Proteins; Resveratrol; Signal Transduction; Stilbenes; Transcription Factors