Comparison of Anti-Inflammatory Analgesics for Mechanical Stress-induced Inflammation in a Human Synovial Sarcoma Cell Line

Osteoarthritis is a complicated clinical condition affected by age, mechanical stress, cartilage hypertrophy, cytokines, and genetic predisposition. In this study, we compared the effects of various anti-inflammatory analgesics on mechanical stress-induced inflammation in a synovial sarcoma cell line （SW982 cells）. SW982 cells exposed to mechanical stress by shaking with hydroxyapatite-simulating bone chips were treated with acetaminophen, ketoprofen, triamcinolone acetonide, celecoxib, or neurotrophin for 48hr. The expression of integrin α5β1 receptor, observed in fibroblasts and synovium, was evaluated. Levels of the transcription factor, nuclear factor-κB, the inflammatory cytokine, tumor necrosis factor-α, the proteolytic enzyme, matrix metalloproteinase-3, and prostaglandin E2, which is associated with pain and arachidonate cascade product levels, were measured by ELISA. The expression of integrin α5β1 was significantly increased by mechanical stress. Activation of nuclear factor-κB by mechanical stress was significantly suppressed by celecoxib only. Mechanical stress-induced increases in tumor necrosis factor-α and matrix metalloproteinase-3 levels were significantly suppressed by acetaminophen, triamcinolone acetonide, and neurotrophin. The mechanical stress-induced increase in prostaglandin E2 levels was significantly suppressed by acetaminophen, ketoprofen, and celecoxib. SW982 exposed to mechanical stress is proposed as a model for arthritis, and indeed, the expression of integrin α5β1, a membrane receptor protein that binds to fibronectin and the extracellular matrix, and is involved in cell proliferation, differentiation, and neovascularization in osteoarthritis, was significantly upregulated. Following evaluation using this model, acetaminophen was found to possess anti-inflammatory, analgesic, and joint-destruction suppression properties. This drug may, therefore, have applications in the treatment of mechanical stress-induced inflammation

Eribulin Treatment Induces High Expression of miR-195 and Inactivates the Wnt/β - catenin Signaling Pathway in Triple-negative Breast Cancer

Triple-negative breast cancer （TNBC） accounts for 10-15％ of all breast cancer cases and shows a poor prognosis with 30％ distant metastasis. With few specific target molecules and ineffective hormonal and anti-HER2 treatment, an alternative therapeutic method for TNBC is urgently required. Recently, a non-taxane inhibitor of microtubule dynamics called eribulin was developed for breast cancer therapy. Eribulin induces irreversible mitotic mass formation in cancer cells during the G2-M phase, initiating apoptosis; however, the mechanism underlying this eribulin activity remains unclear. We reported previously that exposing non-basal-like （NBL） TNBC cells to eribulin increases miR-195 expression, which in turn decreases the expression of targeted Wnt3a. The present study sought to further clarify the mechanism of this antitumor effect by exploring how eribulin affects Wnt/β - catenin signaling based on miRNA expression changes in TNBC. In an NBL type of human breast cancer cell line （MDA-MB-231 cells）, we compared the expression levels of Wnt/β catenin signaling pathway proteins in cells exposed to an miR-195 mimic （cells transfected with miR-195 and in which Wnt3a expression was suppressed） and in cells exposed to eribulin. Expression levels of Wnt3a, β -catenin, and GSK-3β were measured by ELISA and observed by fluorescence immunostaining. Wnt3a and β -catenin expression was significantly lower and GSK-3β expression was significantly higher in the cells exposed to eribulin and transfected with miR-195 mimic than in the untreated controls, suggesting that eribulin inactivates the Wnt/β -catenin signaling pathway. Therefore, a novel antitumor mechanism of eribulin was determined, whereby eribulin induces high expression of miR-195 to inactivate the Wnt/β -catenin signaling pathway in NBL-type TNBC

Establishment of a Mechanical Stress Load Arthritis Model in a Human Synovial Sarcoma Cell Line

Osteoarthritis （OA） is a degenerative disease that occurs in joints throughout the body and includes various concomitant pathologies due to possible mechanical stress, such as destruction of cartilage, hyperplasic changes, and synovial inflammation. However, there have been few studies on the mechanical stress that is the basic cause of OA. Our goal was to establish an OA model at the cellular level, by measuring inflammatory cytokines and cartilage destruction markers that are induced after a mechanical stress load. Using a human synovial sarcoma cell line （SW982 cells）, we provided two types of mechanical stress load for 48hr: shaking stress （amplitude 2mm, speed range 1,000rpm）, and the addition of hydroxyapatite （5?g/ml） into the culture medium. Then we measured the phosphorylation activity of nuclear factor （NF）-κB transcription factor in the cell lysate, and the levels of tumor necrosis factor （TNF）-α and interleukin （IL）-6 as inflammatory cytokines, and the level of matrix metalloproteinase （MMP）-3 as a cartilage destruction marker, released in the medium. Shaking stress significantly induced phosphorylation of NF-κB and production of TNF-α, compared with untreated controls. On the other hand, hydroxyapatite stress only increased production of TNF-α. Both stresses together significantly induced phosphorylation of NF-κB and production of TNF-α, IL-6 and MMP-3 rather than a single stress load. In this study, markers related to inflammation and cartilage destruction （IL-6, TNF-α, and MMP-3） significantly increased. Therefore, we suggest that the mechanical stress load conditions used in this study might be useful as an OA model

Cancer stem-like cells have cisplatin resistance and miR-93 regulate p21 expression in breast cancer

Aim: This study aims to examine the role of microRNAs (miRNAs) in regulating the expression of p21, a cyclin-dependent kinase inhibitor, and in inducing resistance to cisplatin, an anticancer drug. Methods: Human breast cancer cell line MDA-MB231 cells were separated into two subpopulations, cancer stem-like cells (CSCs) and cancer cells, based on the expression of cell surface antigens CD44 and CD24. Results: p21 protein expression was higher in CSCs than in cancer cells. Exposure of MDA-MB-231 cells to cisplatin increased p21 protein expression. However, p21 expression was significantly lower in cisplatin-treated CSCs than in cisplatin-treated cancer cells, suggesting that p21-dependent cell cycle suppression was lower in CSCs than in cancer cells. Moreover, caspase-3 activity was significantly lower in cisplatin-treated CSCs than in cisplatin-treated cancer cells, indicating that CSCs were more resistant to cisplatin-induced apoptosis than cancer cells. Treatment with miR-93 inhibitors increased p21 expression in CSCs, suggesting that miR-93 suppressed p21 expression. Conclusion: The results of the present study indicate that CSCs contribute to cisplatin resistance of MDA-MB231 cells and suggest that miR-93 inhibits the expression of p21, a factor involved in drug resistance