Human Chondrosarcoma Cell Line SW1353 Research Articles

NADPH oxidase 4 facilitates progression of chondrosarcoma via generation of reactive oxygen species.

Nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) is an enzyme that regulates reactive oxygen species (ROS) generation, and its function in the development of chondrosarcoma remains unclear. In the present study, we studied NOX4 expression in chondrosarcoma by immunochemical examination, and analyzed the role of NOX4 in viability and apoptosis of human chondrosarcoma cell line SW1353 using NOX4 siRNA or NOX4 inhibitor GKT137831. NOX4 level significantly increased in tumor compared to that in para-carcinoma sample. The levels of NOX4 were positively correlated with histological grade and Musculoskeletal Tumor Society stage of the patients. NOX4 level was significantly increased in SW1353 compared with that in chondrocytes CHON-001. Knockdown of NOX4 or inhibition of NOX4 by GKT137831 both decreased generation of ROS, and induced growth inhibition and apoptosis in SW1353, accompanied with the activation of caspases (caspase-3, caspase-8 and caspses-9), upregulation of Bax, cytochrome C(cyt-c), cleaved-PARP and down-regulation of Bcl-2. Moreover, NOX4 siRNA and GKT137831 decreased the expression of p-Akt, p-ERK and p-p65 in SW1353 cells. In an in vivo study, NOX4 shRNA transfected SW1353 have shown impaired growth ability compared to the SW1353 when they were injected into the nude mice. Meanwhile, GKT137831 induced growth inhibition and apoptosis in SW1353 xenograft animals, together with increased expression of Bax, cyt-c, cleaved-PARP, and decreased expression of Bcl-2, p-Akt, p-ERK and p-p65. NOX4 plays a positive role in the development of chondrosarcoma and could serve as a promising target against chondrosarcoma clinically.

RNA binding protein GNL3 up-regulates IL24 and PTN to promote the development of osteoarthritis

Osteoarthritis (OA) is a degenerative disease, which has a high incidence in middle-aged and elderly people and tends to occur in weight-bearing or active joints. Current treatment can only relieve symptoms and delay the progression of OA in result of its indistinct pathogenesis. In recent years, more and more studies have focused on the pathogenesis of OA. Nucleolar GTP binding protein 3 (GNL3) is associated with chondrogenic differentiation and can participate in genomic regulation as RNA binding protein (RBP). We used RNA sequencing (RNA-seq) to analyze the overall transcription level of the human cervical cancer cell line HeLa after GNL3 deletion. The results showed that downstream genes IL24 and PTN were down-regulated. IL24 takes part in the progression of OA by inducing articular osteocyte apoptosis, while PTN conducts to the progression of OA by promoting angiogenesis. We validated the results in the human chondrosarcoma cell line SW1353 and OA patients. Compared with the control group, GNL3, IL24 and PTN genes were elevated in OA specimens. This study explored the relationship between GNL3 and these two downstream genes, hoping to find biomarkers in the pathogenesis of osteoarthritis that can be used as therapeutic targets in the future.

Anti-Osteoarthritic Mechanisms of Chrysanthemum zawadskii var. latilobum in MIA-Induced Osteoarthritic Rats and Interleukin-1β-Induced SW1353 Human Chondrocytes.

Background and objectives: Chrysanthemum zawadskii var. latilobum (CZ), which has traditionally been used as a oriental tea in Asia, is known to have anti-inflammatory effects in osteoarthritis (OA). But the mechanism of these effects has not been made clear and it needs to be elucidated specifically for the clinical use of CZE in OA. Materials and Methods: To reveal this mechanism, we first identified which biomarkers were expressed in the joints of rats in which OA had been induced with monosodium iodoacetate and determined whether CZ extract (CZE) could normalize these biomarkers in the progression of OA. The anti-osteoarthritis effect of CZE was evaluated for its capability to inhibit levels of extracellular matrix (ECM)-degrading enzymes and enhance ECM synthesis. We also sought to identify whether the marker compound of CZE, linarin, has anti-osteoarthritic effects in the human chondrosarcoma cell line SW1353. Results: The changes in matrix metalloproteinases (MMPs) were remarkable: among them, MMP-1, MMP-3, MMP-9 and MMP-13 were most strongly induced, whereas their expressions were inhibited by CZE dose dependently. The expressions of the ECM synthetic genes, COL2A1 and ACAN, and the transcription factor SOX9 of these genes were reduced by OA induction and significantly normalized by CZE dose dependently. SOX9 is also a repressor of ECM-degrading aggrecanases, ADAMTS-4 and ADAMTS-5, and CZE significantly reduced the levels of these enzymes dose dependently. Similar results were obtained using the human chondrosarcoma cell line SW1353 with linarin, the biologically active compound of CZE. Conclusions: These anti-osteoarthritic effects suggest that CZE has mechanisms for activating ECM synthesis with SOX9 as well as inhibiting articular ECM-degrading enzymes.

Effects of miR-146a-5p on chondrocyte interleukin-1β-induced inflammation and apoptosis involving thioredoxin interacting protein regulation.

ObjectiveOsteoarthritis (OA) is a chronic degenerative arthropathy characterized by articular cartilage degeneration, subchondral osteosclerosis, and hyperosteogeny. MicroRNAs (miRNAs) play an important regulatory role in its pathological development, so this study explored the effect and potential mechanism of miR-146a-5p in interleukin (IL)-1β-induced OA cartilage injury.MethodsThe human chondrosarcoma cell line SW1353 and normal human chondrocytes C28/I2 were stimulated by IL-1β to construct the OA chondrocyte model. miR-146a-5p and thioredoxin interacting protein (TXNIP) expression levels were detected by quantitative real-time (qRT)-PCR and western blot. Their expression was modified by transfecting an miR-146a-5p inhibitor, mimic, and pcDNA-TXNIP. The relationship between miR-146a-5p and TXNIP was analyzed by the dual-luciferase assay, while cell viability, apoptosis, and inflammatory expression were determined by cell counting, TUNEL staining, and ELISA, respectively.ResultsmiR-146a-5p expression was upregulated in SW1353 and C28/I2 cells stimulated by IL-1β. miR-146a-5p knockdown significantly enhanced cell activity, inhibited inflammatory factor expression, and reduced cell apoptosis. The dual-luciferase assay revealed TXNIP as a target gene of miR-146a-5p and suggested that miR-146a-5p promotion of OA damage could be reversed by upregulating TXNIP.ConclusionThese results suggest that miR-146a-5p inhibits cell proliferation and promotes apoptosis and the inflammatory response in OA cartilage injury by modulating TXNIP.

Anti-Apoptotic Effects of Docosahexaenoic Acid in IL-1β-Induced Human Chondrosarcoma Cell Death through Involvement of the MAPK Signaling Pathway

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.

The specific RIP1 inhibitor necrostatin-1 ameliorated degradation of ECM in human SW1353 cells

Abnormal destruction of the components of the articular extracellular matrix (ECM) such as type II collagen and aggrecan caused by advanced glycation end products (AGEs) has been considered as one of the pathological characteristics of osteoarthritis (OA). Receptor-interacting protein 1 (RIP1), an important serine/threonine kinase, possesses a variety of biological functions including cell proliferation, survival and death. The physiological roles of RIP1 in OA have not been reported before. Here, we found that AGEs increased the expression of RIP1 in human chondrosarcoma cell line SW1353 cells. Importantly, we found that antagonism of RIP1 using its specific inhibitor necrostatin-1 (Nec-1) ameliorated AGE-induced degradation of type II collagen and aggrecan in SW1353 cells. We also found that treatment with Nec-1 reduced the expression of MMP-3 and MMP-13 but restored the expression of Tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2. Also, our results indicate that Nec-1 inhibited AGE-induced expression of ADAMTS-4 and ADAMTS-5. Mechanistically, we found that Nec-1 treatment inhibited the activation of JNK and the transcriptional factor AP-1 by reducing the expressions of c-Fos and c-Jun, the two main components of AP-1. Additionally, we found that Nec-1 treatment abolished AGE-induced activation of the transcriptional factor NF-κB by suppressing the nuclear translocation of p65. These findings suggest that RIP1 might be an important therapeutic target of OA.

Interferon regulatory factor 5 (IRF5) regulates the expression of matrix metalloproteinase-3 (MMP-3) in human chondrocytes

Matrix metalloproteinase-3 (MMP-3) plays a pivotal role in the destruction of articular cartilage in osteoarthritis (OA). The regulation of gene expression of MMP-3 is complicated. Interferon regulatory factor 5 (IRF5) is a member of the interferon regulatory factor family of transcription factors. Little information regarding the biological function of IRF5 on chondrocytes and the pathogenesis of OA has been reported. In the current study, for the first time, we report that IRF5 is expressed in human primary chondrocytes and human chondrosarcoma cell line SW1353 cells. In addition, IRF5 is upregulated in response to TNF-α treatment in a dose dependent manner. Interestingly, IRF5 is significantly higher in chondrocytes from OA patients compared to those from normal subjects. Notably, IRF5 mediates TNF-α- induced expression of MMP-3 in chondrocytes. Overexpression of IRF5 promotes the expression of MMP-3, however, knockdown of IRF5 reduces the expression of MMP-3. Mechanistically, IRF5 is able to enhance the transcription of MMP-3 by binding to its promoter. Also, we found that NF-κB was involved in the effects of IRF-5 on MMP-3 expression. These findings suggest that IRF5 might be a novel pharmacological target for the treatment of OA and RA.

Roxatidine Attenuates Degradation of Extracellular Matrix

Degradation of extracellular matrix such as type II collagen and aggrecan induced by proinflammatory cytokines has been considered as an important hallmark of Osteoarthritis (OA). Roxatidine is a licensed specific competitive H (2) −receptor antagonist used for the treatment of gastric and duodenal ulcers. The pharmacological function of roxatidine on Osteoarthritis (OA) remains unknown. In the current study, we report that roxatidine attenuated TNF-α- induced degradation of type II collagen by suppressing the expression of MMP-3 and MMP-13 in human chondrosarcoma cell line SW1353 cells. In addition, roxatidine ameliorated TNF-α- induced reduction of aggrecan by inhibiting the expression of ADAMTS-4 and ADAMTS-5. Notably, results indicate that roxatidine ameliorated TNF-α- induced the phosphorylations of IKK, IκBα, and NF-κB p65 as well as nuclear translocation of NF-κB p65 and the transcriptional activity of NF-κB, suggesting that roxatidine abolished the activation of NF-κB signaling pathway. Our findings implicate that roxatidine might be considered as an anti-osteoarthritic agent.

Puerarin induces cell apoptosis in human chondrosarcoma cell line SW1353 via inhibition of the PI3K/Akt signaling pathway

Chondrosarcoma is a malignant soft tissue sarcoma with poor prognosis. Puerarin has been demonstrated to possess anticancer properties; however, the effects of puerarin in human chondrosarcoma cells remain unknown. The present study aimed to investigate the anticancer effects of puerarin in SW1353 human chondrosarcoma cells. SW1353 cells were treated with increasing concentrations of puerarin for different durations. Cell viability was evaluated using MTT assays. Cell apoptosis rates were determined by flow cytometry. The activities of caspase-3 and caspase-9 were measured by enzymatic assay. The expression of RAC-alpha serine/threonine-protein kinase (Akt), phosphorylated-Akt, caspase-3 and apoptosis-associated proteins, including B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) were detected by western blotting. Puerarin significantly decreased cell viability and significantly induced apoptosis of SW1353 cells. In addition, puerarin significantly increased the enzymatic activities of caspase-3 and caspase-9. Puerarin treatment suppressed the expression of p-Akt and Bcl-2 but promoted the expression of Bax and cleaved caspase-3 in SW1353 cells. Notably, the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 abrogated the decreased phosphorylation of Akt, suggesting that the PI3K/Akt signaling pathway is involved in mediating the anticancer effects of puerarin. The data from the present study indicated that puerarin exhibits anticancer effects in SW1353 cells and may be a potential therapeutic drug for patients with chondrosarcoma.

Inhibiting ROS-TFEB-Dependent Autophagy Enhances Salidroside-Induced Apoptosis in Human Chondrosarcoma Cells

Background/Aims: Autophagy modulation has been considered a potential therapeutic strategy for human chondrosarcoma, and a previous study indicated that salidroside exhibits significant anti-carcinogenic activity. However, the ability of salidroside to induce autophagy and its role in human chondrosarcoma cell death remains unclear. Methods: We exposed SW1353 cells to different concentrations of salidroside (0.5, 1 and 2 mM) for 24 h. RT-PCR, Western-blotting, Immunocytofluorescence, and Luciferase Reporter Assays were used to evaluate whether salidroside activated the TFEB-dependent autophagy. Results: We show that salidroside induced significant apoptosis in the human chondrosarcoma cell line SW1353. In addition, we demonstrate that salidroside-induced an autophagic response in SW1353 cells, as evidenced by the upregulation of LC3-II and downregulation of P62. Moreover, pharmacological or genetic blocking of autophagy enhanced salidroside -induced apoptosis, indicating the cytoprotective role of autophagy in salidroside-treated SW1353 cells. Salidroside also induced TFEB ^(Ser142) dephosphorylation, subsequently to activated TFEB nuclear translocation and increase of TFEB reporter activity, which contributed to lysosomal biogenesis and the expression of autophagy-related genes. Importantly, we found that salidroside triggered the generation of ROS in SW1353 cells. Furthermore, NAC, a ROS scavenger, abrogated the effects of salidroside on TFEB-dependent autophagy. Conclusions: These data demonstrate that salidroside increased TFEB-dependent autophagy by activating ROS signaling pathways in human chondrosarcoma cells. These data also suggest that blocking ROS-TFEB-dependent autophagy to enhance the activity of salidroside warrants further attention in treatment of human chondrosarcoma cells.

Elevated expression of microRNA-30b in osteoarthritis and its role in ERG regulation of chondrocyte.

ERG (ETS-related gene) belongs to the ETS family of transcription factors, and has been recently reported to contribute to homeostatic balance in skeleton cell plasticity. MicroRNA-30 (miR-30) family is also demonstrated to play a role in controlling chondrocyte differentiation. The current study investigated the miR-30b and ERG expression in articular cartilage of osteoarthritis (OA) patients. A total of 20 subjects, with 10 OA patients and 10 healthy participants, were included in this study. Human chondrosarcoma cell line SW1353 was used to explore the relationship of miR-30b and ERG in vitro. In OA patients, a significant increase of miR-30b and a decrease of ERG were observed in articular cartilage compared with Normal ones. MiR-30b mimic down-regulated the ERG mRNA and protein expression levels, while miR-30b inhibitor up-regulated ERG expression. In addition, miR-30b mimic also decreased the mRNA expression of COL2a and aggrecan, while miR-30b inhibitor had the opposite effect. Luciferase reporter assay confirmed that miR-30b targeted ERG. In conclusion, miR-30b was involved in the process of OA, and it probably functioned through its target gene ERG.

Evaluating the role of PTH in promotion of chondrosarcoma cell proliferation and invasion by inhibiting primary cilia expression.

Chondrosarcoma is characterized by secretion of a cartilage-like matrix, with high proliferation ability and metastatic potential. Previous studies have shown that parathyroid hormone-related protein (PTHrP) has a close relationship with various tumor types. The objectives of this study were to research the function played by PTHrP in human chondrosarcoma, especially targeting cell proliferation and invasion, and to search for the potential interaction between PTHrP and primary cilia in tumorigenesis. Surgical resection tissues and the human chondrosarcoma cell line SW1353 were used in the scientific research. Cells were stimulated with an optimum concentration of recombinant PTH (1-84), and siRNA was used to interfere with internal PTHrP. Cell proliferation and invasion assays were applied, including MTS-8 cell proliferation assay, Western blot, RT-PCR, Transwell invasion assay, and immunohistochemistry and immunofluorescence assays. A high level of PTHrP expression was found in human chondrosarcoma tissues, and recombinant PTH exhibited positive promotion in tumor cell proliferation and invasion. In the meantime, PTHrP could inhibit the assembly of primary cilia and regulate downstream gene expression. These findings indicate that PTHrP can regulate tumor cell proliferation and invasion ability, possibly through suppression of primary cilia assembly. Thus, restricting PTHrP over-expression is a feasible potential therapeutic method for chondrosarcoma.

α-Mangostin Induces Apoptosis in Human Chondrosarcoma Cells through Downregulation of ERK/JNK and Akt Signaling Pathway

Chondrosarcoma is a malignant primary bone tumor that is resistant to chemotherapy and radiation therapy. α-Mangostin, a component of Garcinia mangostana Linn, is a xanthone derivative shown to have antioxidant and antitumor properties. This study is the first to investigate anticancer effects of α-mangostin in the human chondrosarcoma cell line SW1353. We showed that α-mangostin inhibited cell proliferation of SW1353 cells in a time- and dose-dependent manner by using the trypan blue exclusion method. Hoechst 33342 nuclear staining and nucleosomal DNA-gel electrophoresis revealed that α-mangostin could induce nuclear condensation and fragmentation, typically seen in apoptosis. Flow cytometry using Annexin V/PI double staining assessed apoptosis, necrosis and viability. α-Mangostin activated caspase-3, -8, -9 expression, decreased Bcl-2 and increased Bax. This promotes mitochondrial dysfunction, leading to the release of cytochrome c from the mitochondria to the cytoplasm. In addition, total and phosphorylated ERK and JNK were downregulated in α-mangostin-treated SW1353 cells but no changes in p38. α-Mangostin also decreased phosphorylated Akt without altering total Akt. These results suggest that α-mangostin inhinbited cell proliferation and induced apoptosis through downregulation of ERK, JNK and Akt signaling pathway in human chondrosarcoma SW1353 cells.

Induction of apoptosis by anti-CD44 antibody in human chondrosarcoma cell line SW1353

Because chondrosarcoma is resistant to chemotherapy and ionizing radiation, the primary treatment of chondrosarcoma is surgical resection. Effective chemotherapeutic agents for chondrosarcoma are necessary. Although there is evidence that CD44 is involved in apoptosis susceptibility in several cell types, the effectiveness of anti-CD44 treatment on chondrosarcoma has never been studied. This study was aimed to clarify whether anti-CD44 monoclonal antibody induces apoptosis in human chondrosarcoma cell line SW1353. Confocal microscopy revealed that the SW1353 cells expressed CD44 that bound the anti-CD44 antibody IM7. Treatment of the cells with IM7 resulted in a significant decrease in cell viability, compared with that with control IgG. In contrast, IM7 failed to reduce cell viability in human chondrocytes. In SW1353 cells, IM7 induced chromatin condensation, nuclear fragmentation, and apoptotic body formation while control IgG had marginal effect. These data indicate that anti-CD44 treatment could induce apoptosis in chondrosarcoma cells.

TAK1 downregulation reduces IL-1β induced expression of MMP13, MMP1 and TNF-alpha

The paper provides evidence that transforming growth factor-beta activated kinase 1 (TAK1, MEKK7), a downstream mediator of IL-1β signal transduction, plays an important role in the regulation of catabolic events and inflammatory processes in the context of degenerative joint diseases. We investigated the expression of TAK1 in human articular chondrocytes and in the murine growth plate by cDNA array, quantitative RT-PCR and immunohistochemistry, respectively. The human chondrosarcoma cell line SW1353 was stimulated with the proinflammatory cytokine IL-1β. The subsequent expression of proteolytic enzymes and proinflammatory cytokines was quantified. TAK1 specific siRNA was used to study the influence of TAK1 downregulation on the expression of MMP-13, MMP1 and TNF-α. As a result we demonstrated the expression of TAK1 in normal and osteoarthritic human articular cartilage. Expression of TAK1 in the hypertrophic zone of the growth plate gave us a first evidence for a catabolic function of TAK1 concerning cartilage metabolism. By gene suppression with RNAi technology we could show that TAK1 downregulation leads to a 60–70% reduced release of TNF-α, a 40–50% reduced release of MMP13, and a 20–30% reduction of MMP1 release. As TNF-α is a main player in inflammatory processes, and MMP13 is one of the major proteases involved in cartilage degradation, our results suggests that TAK1 has an important regulatory role in the context of degenerative joint diseases and thus is an attractive drug target in attempts to reduce inflammation and suppress structural changes in OA induced by IL-1β.

Novel p38 mitogen-activated protein kinase inhibitor R-130823 protects cartilage by down-regulating matrix metalloproteinase-1,-13 and prostaglandin E2 production in human chondrocytes

In order to study the involvement of mitogen-activated protein kinase p38 in osteoarthritis, we investigated the effect of novel p38 inhibitor R-130823 {2-(4-fluorophenyl)-4-(1-phenethyl-1,2,3,6-tetrahydropyridin-4-yl)-3-(pyridin-4-yl)-1H-pyrrole} on human chondrocytes and bovine cartilage. In human primary chondrocytes, the production of matrix metalloproteinase-13 and -1 (MMP-13 and -1) and prostaglandin E2 (PGE2) was induced by interleukin-1β. Pretreatment with R-130823 inhibited the release of MMP-13, MMP-1 and PGE2 with IC50 values of 20, 230 and 3.9 nM, respectively. The inhibitory activity was also confirmed by a decrease in MMP-13 release from human chondrosarcoma cell line SW1353 with an IC50 value of 17 nM. Ribonuclease protection assay on human primary chondrocytes indicated that MMP-13 and MMP-1 mRNA levels almost reached the maximum 14 h after IL-1 stimulation, while cyclooxygenase-2 (COX-2) mRNA quickly reached the maximum 4 h after the stimulation. R-130823 down-regulated the steady-state levels of MMP-13 and MMP-1 mRNA with IC50 values of 4.2 and 79 nM, respectively. The COX-2 mRNA level was also suppressed with an IC50 value of 21 nM. In the explant culture of bovine nasal cartilage, R-130823 suppressed the collagen cleavage induced by interleukin-1α and oncostatin M, but not IL-1β-mediated glycosaminoglycan release. These results suggest that activated p38 accelerates cartilage breakdown by enhancing the expression of MMPs responsible for collagen cleavage, which thus implies chondroprotective effects of p38 inhibitors in osteoarthritis.

Comparison of the chondrosarcoma cell line SW1353 with primary human adult articular chondrocytes with regard to their gene expression profile and reactivity to IL-1β

In this study, the human chondrosarcoma cell line SW1353 was investigated by gene expression analysis in order to validate it as an in vitro model for primary human (adult articular) chondrocytes (PHCs). PHCs and SW1353 cells were cultured as high density monolayer cultures with and without 1ng/ml interleukin-1beta (IL-1beta). RNA was isolated and assayed using a custom-made oligonucleotide microarray representing 312 chondrocyte-relevant genes. The expression levels of selected genes were confirmed by real-time polymerase chain reaction and the gene expression profiles of the two cell types, both with and without IL-1beta treatment, were compared. Overall, gene expression profiling showed only very limited similarities between SW1353 cells and PHCs at the transcriptional level. Similarities were predominantly seen with respect to catabolic effects after IL-1beta treatment. In both cell systems matrix metalloproteinase-1 (MMP-1), MMP-3 and MMP-13 were strongly induced by IL-1beta, without significant induction of MMP-2. IL-6 was also found to be up-regulated by IL-1beta in both cellular models. On the other hand, intercellular mediators such as leukemia inhibitory factor (LIF) and bone morphogenetic protein-2 (BMP-2) were not induced by IL-1beta in SW1353 cells, but significantly up-regulated in PHCs. Bioinformatical analysis identified nuclear factor kappa-B (NFkappaB) as a common transcriptional regulator of IL-1beta induced genes in both SW1353 cells and PHCs, whereas other transcription factors were only found to be relevant for individual cell systems. Our data characterize SW1353 cells as a cell line with only a very limited potential to mimic PHCs, though SW1353 cells can be of value to study the induction of protease expression within cells, a phenomenon also seen in chondrocytes.