Gentiopicroside ameliorates the lipopolysaccharide-induced inflammatory response and hypertrophy in chondrocytes.

PURPOSE: This study aimed to evaluate the protective effects of gentiopicroside against lipopolysaccharide-induced chondrocyte inflammation. METHODS: SW 1353 chondrosarcoma cells were stimulated with LPS (5 µg/ml) for 24 h and treated with different concentrations of gentiopicroside (GPS) for 24 h. The toxic effects of GPS on chondrocytes were determined using a CCK-8 assay and EdU staining. Western blotting, qPCR, and immunofluorescence analysis were used to examine the protective effect of GPS against the inflammatory response in chondrocytes induced by lipopolysaccharide (LPS). One-way ANOVA was used to compare the differences between the groups (significance level of 0.05). RESULTS: The CCK-8 results showed that 10, 20 and 40 µM GPS had no significant toxic effects on chondrocytes; GPS effectively reduced the production of IL-1ß and PGE2, reversed LPS-induced extracellular matrix degradation in cartilage by inhibiting the Stat3/Runx2 signaling pathway, and suppressed the hypertrophic transformation of SW 1353 chondrosarcoma cells. CONCLUSION: Our study demonstrated that GPS significantly inhibited the LPS-induced inflammatory response and hypertrophic cellular degeneration in SW 1353 chondrosarcoma cells and is a valuable traditional Chinese medicine for the treatment of knee osteoarthritis.

Impact of Prior Cancer on the Prognosis of Patients with Chondrosarcoma: A Population-Based Study of the SEER Database.

Background: Patients with prior cancer are generally exempt from cancer experiments. This research aims to describe the prevalence, clinical features, and effects of past malignancy among patients with chondrosarcoma. Methods: Chondrosarcoma patients diagnosed between 2010 to 2015 were collected from the SEER database. The propensity score matching method was used to reconcile the disparity in baseline attributes. Kaplan-Meier analysis was employed to explore the outcomes of prior cancer on overall survival. The proportional hazards assumption was used to certain whether the covariate matched the Cox regression model. The potential outliers were estimated by deviance residuals type. Results: A total of 1,721 unique individuals were collected, of those 284 (16.50%) patients had a history of cancer, with prostate cancer being commonly documented (n = 49, 17.25%). Approximately half of the previous tumors are diagnosed within 5 years before the diagnosis of chondrosarcoma. Chondrosarcoma patients with prior cancers have a lower survival rate than those without prior malignancy (P < .001). A multivariable Cox analysis reveals that past cancer is a distinct risk factor for lifespan (hazard ratio = 2.489, P < .001). Conclusion: This study initially discovered that chondrosarcoma patients with past cancer have a bad prognosis. Different types of past cancer have varying effects on survival. We urgently propose that cancer trial exclusion criteria be set specifically by cancer classification, rather than accepting the unchangeable criterion for default.

Cytotoxic Effects of Common Irrigation Solutions on Chondrosarcoma and Giant Cell Tumors of Bone.

BACKGROUND: Irrigation is commonly used as an adjuvant treatment during the intralesional curettage of bone tumors. The goal of the present study was to analyze the in vitro cytotoxicity of commonly used irrigation solutions on chondrosarcoma and giant cell tumor (GCT) cells as there is no consensus on which solution leads to the greatest amount of cell death. METHODS: An in vitro evaluation was performed by exposing human GCT and human chondrosarcoma cell lines to 0.9% saline solution, sterile water, 70% ethanol, 3% hydrogen peroxide, 0.05% chlorhexidine gluconate (CHG), and 0.3% povidone iodine solutions independently for 2 and 5 minutes. A low-cytotoxicity control (LCC) and a high-cytotoxicity control (HCC) were established to determine the mean cytotoxicity of each solution and each solution's superiority to LCC and non-inferiority to HCC. RESULTS: The present study demonstrated that 0.05% CHG was non-inferior to the HCC when chondrosarcoma was exposed for 5 minutes and when GCT was exposed for 2 and 5 minutes (mean cytotoxicity, 99% to 102%) (p < 0.003 for all). Sterile water was superior to the LCC when chondrosarcoma was exposed for 5 minutes and when GCT was exposed for 2 minutes (mean, 28% to 37%) (p < 0.05). Sterile water (mean, 18% to 38%) (p < 0.012) and 3% hydrogen peroxide (mean, 7% to 16%) (p < 0.001) were both inferior to the HCC. The 3 other solutions were non-superior to the LCC (mean, -24% to -5%) (p < 0.023). CONCLUSIONS: In vitro irrigation in 0.05% CHG provided high cytotoxicity, comparable with the HCC. Therefore, the use of a 0.05% CHG solution clinically could serve as a potential chemical adjuvant during intralesional curettage of chondrosarcoma and GCT. CLINICAL RELEVANCE: In an effort to reduce the burden of residual tumor cells, irrigation solutions are often utilized as adjuvant local therapy. Use of a 0.05% CHG solution clinically could serve as a potential chemical adjuvant to intralesional curettage of chondrosarcoma and GCT. Further in vivo studies may be indicated to assess clinical outcomes and safety associated with the use of 0.05% CHG in the treatment of chondrosarcoma and GCT.

Transcriptomic Analysis of the Anticancer Effects of Annatto Tocotrienol, Delta-Tocotrienol and Gamma-Tocotrienol on Chondrosarcoma Cells.

Previous studies have demonstrated the anticancer activities of tocotrienol on several types of cancer, but its effects on chondrosarcoma have never been investigated. Therefore, this study aims to determine the anticancer properties of annatto tocotrienol (AnTT), γ-tocotrienol (γ-T3) and δ-tocotrienol (δ-T3) on human chondrosarcoma SW1353 cells. Firstly, the MTT assay was performed to determine the half-maximal inhibitory concentration (IC50) of tocotrienol on SW1353 cells after 24 h treatment. The mode of cell death, cell cycle analysis and microscopic observation of tocotrienol-treated SW1353 cells were then conducted according to the respective IC50 values. Subsequently, RNAs were isolated from tocotrienol-treated cells and subjected to RNA sequencing and transcriptomic analysis. Differentially expressed genes were identified and then verified with a quantitative PCR. The current study demonstrated that AnTT, γ-T3 and δ-T3 induced G1 arrest on SW1353 cells in the early phase of treatment (24 h) which progressed to apoptosis upon 48 h of treatment. Furthermore, tocotrienol-treated SW1353 cells also demonstrated large cytoplasmic vacuolation. The subsequent transcriptomic analysis revealed upregulated signalling pathways in endoplasmic reticulum stress, unfolded protein response, autophagy and transcription upon tocotrienol treatment. In addition, several cell proliferation and cancer-related pathways, such as Hippo signalling pathway and Wnt signalling pathway were also significantly downregulated upon treatment. In conclusion, AnTT, γ-T3 and δ-T3 possess promising anticancer properties against chondrosarcoma cells and further study is required to confirm their effectiveness as adjuvant therapy for chondrosarcoma.

Management of Primary Aggressive Tumors of the Knee.

Primary bone sarcomas and aggressive benign bone tumors are relatively rare. It is essential to recognize features that are concerning for these aggressive tumors based on a patient's history, physical exam, and radiographs. Physicians and other health care providers should have a high suspicion for these tumors and promptly refer these patients to orthopaedic oncologists. A multidisciplinary, team-based approach is required to obtain an accurate diagnosis and provide comprehensive care. This review discussed the appropriate work-up, biopsy principles, relevant peri-operative medical management, and surgical treatment options for patients with aggressive primary bone tumors around the knee. Primary bone sarcomas (osteosarcoma and chondrosarcoma) and aggressive benign bone tumors (giant cell tumor, chondroblastoma, and chondromyxoid fibroma) that have a predilection to the distal femur and proximal tibia are the focus of this review.

Distinct Roles of Glutamine Metabolism in Benign and Malignant Cartilage Tumors With IDH Mutations.

Enchondromas and chondrosarcomas are common cartilage neoplasms that are either benign or malignant, respectively. The majority of these tumors harbor mutations in either IDH1 or IDH2. Glutamine metabolism has been implicated as a critical regulator of tumors with IDH mutations. Using genetic and pharmacological approaches, we demonstrated that glutaminase-mediated glutamine metabolism played distinct roles in enchondromas and chondrosarcomas with IDH1 or IDH2 mutations. Glutamine affected cell differentiation and viability in these tumors differently through different downstream metabolites. During murine enchondroma-like lesion development, glutamine-derived α-ketoglutarate promoted hypertrophic chondrocyte differentiation and regulated chondrocyte proliferation. Deletion of glutaminase in chondrocytes with Idh1 mutation increased the number and size of enchondroma-like lesions. In contrast, pharmacological inhibition of glutaminase in chondrosarcoma xenografts reduced overall tumor burden partially because glutamine-derived non-essential amino acids played an important role in preventing cell apoptosis. This study demonstrates that glutamine metabolism plays different roles in tumor initiation and cancer maintenance. Supplementation of α-ketoglutarate and inhibiting GLS may provide a therapeutic approach to suppress enchondroma and chondrosarcoma tumor growth, respectively. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Biological and Cytoprotective Effect of Piper kadsura Ohwi against Hydrogen-Peroxide-Induced Oxidative Stress in Human SW1353 Cells.

Oxidative stress plays a role in regulating a variety of physiological functions in living organisms and in the pathogenesis of articular cartilage diseases. Piper kadsura Ohwi is a traditional Chinese medicine that is used as a treatment for rheumatic pain, and the extracts have anti-inflammatory and antioxidant effects. However, there is still no study related to cell protection by P. kadsura. The P. kadsura extracts (PKE) were obtained by microwave-assisted extraction, liquid-liquid extraction, and column chromatography separation. The extracts could effectively scavenge free radicals in the antioxidant test, the EC50 of extracts is approximately the same as vitamin C. PKE decreased the apoptosis of SW1353 cells treated with H2O2 and could upregulate the gene expression of antioxidant enzymes (SOD-2, GPx, and CAT) and the Bcl-2/Bax ratio, as well as regulate PARP, thus conferring resistance to H2O2 attack. PKE protects cells against apoptosis caused by free radicals through the three pathways of JNK, MEK/ERK, and p38 by treatment with MAPK inhibitor. The identified components of PKE were bicyclo [2.2.1] heptan-2-ol-1,7,7-trimethyl-,(1S-endo)-, alpha-humulene, and hydroxychavicol by gas chromatography-mass spectrometry.

Inhibitory effects on chondrosarcoma cell metastasis by Senna alata extract.

BACKGROUND: Senna alata L. Roxb or candle bush is a traditional medicinal plant with a wide range of biological activities including anti-inflammatory, antimicrobial and antifungal. Leaf extract of S. alata showed the anti-tumor activity in various cancer cell lines. In this study, we focused on the inhibitory mechanism of S. alata extract (SAE) on cancer metastasis including cell migration, cell invasion and signaling pathways in chondrosarcoma SW1353 cells. PURPOSE: This study aimed to evaluate the anti-metastatic mechanisms of Senna alata extract on chondrosarcoma SW1353 cells. METHODS: Screening for phytochemicals in biologically active fraction of SAE was analysed by 1H NMR spectroscopy. Cell viability and cytoxicity were determined by using MTT assay. Cell migration was observed by scratch wound healing and transwell migration assay. Cell invasion and cell adhesion assay were examined by Matrigel coated transwell chambers or plates. The expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), MAPKs and PI3K/Akt signaling pathways and NF-κB were detected by Western blot analysis. RESULTS: The SAE treatment at the sub-cytoxic and non-cytotoxic concentrations significantly inhibited cell migration, cell invasion and cell adhesion of SW1353 cells in a dose-dependent manner. The results from Western blot analysis showed decreased MMP-2 and MMP-9 expression, while increased TIMP-1 and TIMP-2 expression in SAE treated cells. Moreover, SAE suppressed phosphorylation of ERK1/2, p38 and Akt but decreased NF-κB transcription factor expression in SW1353 cells. CONCLUSION: These results revealed that SAE could reduce MMP-2 and MMP-9 expression by downregulation of NF-κB which is downstream of MAPKs and PI3K/Akt signaling pathway in SW1353 cells resulting in reduced cancer cell migration and invasion. Therefore, SAE may have the potential use as an alternative treatment of chondrosarcoma metastasis.

Bisphosphonates in common pediatric and adult bone sarcomas.

The therapeutic strategies proposed currently for bone sarcomas are based on neo-adjuvant chemotherapy, delayed en-bloc wide resection, and adjuvant chemotherapy. Unfortunately, bone sarcomas are characterized by high rates of poor drug response, with a high risk of drug resistance, local recurrence and/or a high propensity for induced metastases. The pathogenesis of bone sarcomas is strongly associated with dysregulation of local bone remodeling and increased osteolysis that plays a part in tumor development. In this context, bisphosphonates (BPs) have been proposed as a single agent or in combination with conventional drugs to block bone resorption and the vicious cycle established between bone and sarcoma cells. Pre-clinical in vitro studies revealed the potential "anti-tumor" activities of nitrogen-bisphosphonates (N-BPs). In pre-clinical models, N-BPs reduced significantly primary tumor growth in osteosarcoma and Ewing sarcoma, and the installation of lung metastases. In chondrosarcoma, N-BPs reduced the recurrence of local tumors after intralesional curettage, and increased overall survival. In pediatric and adult osteosarcoma patients, N-BPs have been assessed in combination with conventional chemotherapy and surgery in randomized phase 3 studies with no improvement in clinical outcome. The lack of benefit may potentially be explained by the biological impact of N-BPs on macrophage differentiation/recruitment which may alter CD8+-T lymphocyte infiltration. Thanks to their considerable affinity for the mineralized extracellular matrix, BPs are an excellent platform for drug delivery in malignant bone sites with reduced systemic toxicity, which opens up new opportunities for their future use.

Is Skeletal Imaging Essential in the Staging Workup for Conventional Chondrosarcoma?

BACKGROUND: Staging of a bone sarcoma before initiating treatment helps orthopaedic oncologists determine the intent of treatment and predicting the prognosis. As per National Comprehensive Cancer Network (NCCN) and European Society for Medical Oncology (ESMO) guidelines, there are no exclusive recommendations for chondrosarcoma staging. They are staged similar to other bone sarcomas even though skeletal metastases are extremely rare in chondrosarcomas. QUESTIONS/PURPOSES: We asked: (1) What proportion of patients with a chondrosarcoma present with detectable only skeletal metastasis? (2) What proportion of patients with chondrosarcoma present with skeletal metastasis with or without concurrent pulmonary metastases? METHODS: Between January 2006 to December 2017, 480 patients with histology-proven chondrosarcomas of the extremity, including clavicle, scapula, spine, and pelvis, presented to our institute. Fifty-three patients were excluded due to incomplete details about their staging. The remaining 427 were retrospectively analyzed and included in this study. Their clinical, radiological, and histopathological details were retrieved from patient files and electronic medical records. Of the 427 patients included, 53 had Grade 1 chondrosarcoma, 330 had Grade 2 chondrosarcoma, and 41 had Grade 3 chondrosarcoma. Grade was not available in three patients. All patients were staged with a thoracic CT scan and bone scan or a whole body fluorodeoxyglucose positron-emission tomography/CT (FDG PET/CT). Patients with a suspected or documented metastasis were reviewed again by an experienced radiologist and a nuclear medicine expert for the purpose of this study. A total of 8% (35 of 427) of patients with chondrosarcoma had isolated lung metastases at the time of initial staging. These included 9% (31 of 330) of patients with Grade 2 chondrosarcomas and 10% (4 of 41) of patients with Grade 3 chondrosarcomas. No patient with a Grade 1 chondrosarcoma had detectable lung metastases. The primary study endpoint was the number of patients who had a diagnosis of skeletal or skeletal and lung metastases as identified by the staging modalities. RESULTS: Three patients with Grade 2 chondrosarcoma had only skeletal metastasis. No patients with Grade 1 or Grade 3 chondrosarcoma had detectable bone metastases. Combined lung and bone metastases were seen in only two patients with Grade 2 chondrosarcoma. CONCLUSIONS: Our study found that the incidence of bony metastasis in conventional chondrosarcomas is extremely low. Considering the present results, we believe skeletal scanning may be overused in current staging algorithms. We do not have survival outcomes to know if detecting these few patients with skeletal lesions at initial presentation would be important in the absence of symptoms, but our data suggest that omitting skeletal imaging from the staging work-up of conventional chondrosarcomas should be considered. It may be reserved for patients with documented pulmonary metastases. LEVEL OF EVIDENCE: Level IV, diagnostic study.

An update on current and future treatment options for chondrosarcoma.

Introduction: Human chondrosarcomas (CS; a malignant cartilage-forming bone tumor) respond poorly to chemotherapy and radiation treatment, resulting in high morbidity and mortality rates. Expanded treatment options are urgently needed. Areas covered: This article updates our 2014 review, in which we evaluated the CS treatments available at that time and potential treatment options under investigation. Since then, advances in research findings, particularly from Chinese herbal medicines, may be bringing us closer to more effective therapies for CS. In particular, promising findings have been reported from research targeting platelet-derived growth factor receptor. Expert opinion: Few treatment options exist for CS; chemotherapy is not even an option for unresectable disease, in which 5-year survival rates are just 2%. New information about the multitude of genes and signaling pathways that encourage CS growth, invasion and metastasis are clarifying how certain signaling pathways and plant-derived active compounds, especially molecularly-targeted therapies that inhibit the PDGF receptor, interfering with these biological processes. This review summarizes discoveries from the last 5 years and discusses how these findings are fueling ongoing work into effectively dealing with the disease process and improving the treatment of CS.

Anti-Apoptotic Effects of Docosahexaenoic Acid in IL-1ß-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-1ß 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-1ß 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-1ß, inhibits IL-1ß-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.

Baicalin Induces Apoptotic Death of Human Chondrosarcoma Cells through Mitochondrial Dysfunction and Downregulation of the PI3K/Akt/mTOR Pathway.

The aim of the present study was to investigate the cytotoxic and antitumour effects of baicalin in human chondrosarcoma both in vivo and in vitro. We examined the effects of baicalin on the growth and apoptosis of human chondrosarcoma cells. Baicalin inhibited the growth of SW1353 and CH2879 cells in a dose- and time-dependent manner, but did not inhibit the growth of normal chondrocytes. Baicalin reduced tumour growth and induced apoptotic death in SW1353-transplanted nude mice without reducing their body weight. Further studies showed that baicalin reduced the mitochondrial membrane potential, upregulated the expression of Bax and cytoplasmic cytochrome c, downregulated the expression of Bcl-2 and mitochondrial cytochromes, and activated caspase-3 and caspase-9. Baicalin inhibited the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathway by decreasing the expression of phosphorylated phosphoinositide 3-kinase, phosphorylated protein kinase B, and phosphorylated mammalian target of rapamycin both in vivo and in vitro. Moreover, the mice that received SC79 and baicalin exhibited a greater tumour size compared with the mice that received baicalin. The mice that received LY294002 and baicalin showed a smaller tumour size compared with the mice that received baicalin. In the in vitro study, SC79 and LY294002 affected the baicalin-induced cytotoxic effects on chondrosarcoma cells in the same manner. Our data suggest baicalin has therapeutic efficacy in human chondrosarcoma through the induction of apoptosis and inhibition of the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathway. Baicalin can be considered a potential therapeutic agent for treating chondrosarcomas.

Inhibition of Osteoarthritis-Related Molecules by Isomucronulatol 7-O-ß-d-glucoside and Ecliptasaponin A in IL-1ß-Stimulated Chondrosarcoma Cell Model.

Osteoarthritis (OA) is the common form of arthritis and is characterized by disability and cartilage degradation. Although natural product extracts have been reported to have anti-osteoarthritic effects, the potential bioactivity of Ryupunghwan (RPH), a traditional Korean medicinal botanical formula that contains Astragalus membranaceus, Turnera diffusa, Achyranthes bidentata, Angelica gigas, Eclipta prostrata, Eucommia ulmoides, and Ilex paraguariensis, is not known well. Therefore, the inhibitory effects of single compounds isolated from RPH on the OA-related molecules were investigated using IL-1ß-stimulated chondrosarcoma SW1353 (SW1353) cell model. Two bioactive compounds, isomucronulatol 7-O-ß-d-glucoside (IMG) and ecliptasaponin A (ES) were isolated and purified from RPH using column chromatography, and then the structures were analyzed using ESI-MS, ¹H-NMR, and 13C-NMR spectrum. The expression or amount of matrix metalloproteinase 13 (MMP13), COX1/2, TNF-α, IL-1ß or p65 was determined by RT-PCR, Western blot, and enzyme-linked immunosorbent assay (ELISA). RPH pretreatment reduced the expression and amounts of MMP13, and the expression of collagen II, COX1/2, TNF-α, IL-1ß or p65, which were increased in IL-1ß-stimulated SW1353 cells. IMG reduced the expression of all OA-related molecules, but the observed inhibitory effect was less than that of RPH extract. The other single compound ES showed the reduced expression of all OA-related molecules, and the effect was stronger than that in IMG (approximately 100 fold). Combination pretreatment of both single components remarkably reduced the expression of MMP13, compared to each single component. These synergic effects may provide potential molecular modes of action for the anti-osteoarthritic effects of RPH observed in clinical and animal studies.

Effects of ethanol on the anticancer function of doxorubicin in JJ012 cells.

AIM: Chondrosarcoma is difficult to treat because of resistance to conventional chemotherapy and radiotherapy. This study evaluated the effects of ethanol in combination with doxorubicin in chondrosarcoma cells. MATERIALS & METHODS: JJ012, was treated with doxorubicin alone or in combination with ethanol. Effects on cellular proliferation, migration, invasion, apoptosis, and the cell cycle were evaluated. RESULTS: Treatment of JJ012 cells with 100 mM ethanol and doxorubicin resulted in reduced cell growth, invasion, and migration. In addition, doxorubicin uptake into the nucleus was enhanced and p53 mRNA expression was upregulated in JJ012 cells. CONCLUSION: Ethanol combined with doxorubicin increased doxorubicin uptake in the nucleus and enhanced the effects of doxorubicin in JJ012 cells.

GABAB receptor regulates proliferation in the high-grade chondrosarcoma cell line OUMS-27 via apoptotic pathways.

BACKGROUND: High-grade chondrosarcoma, which has a high incidence of local recurrence and pulmonary metastasis despite surgical resection, is associated with poor prognosis. Therefore, new and effective adjuvant therapies are urgently required for this disease. Gamma-aminobutyric acid (GABA), which acts as a neurotrophic factor during nervous system development, is related to the proliferation and migration of certain cancer cells. The GABAergic system, which is composed of GABA, the GABA-synthesizing enzyme glutamic acid decarboxylase (GAD), and GABA receptors, has an important function in nerve growth and development of neural crest. Therefore, the GABAergic system may play important functional roles in the proliferation of chondrosarcoma cells, which are derived from neural crest cells. We examined the anti-tumor effects of the GABAergic system on a chondrosarcoma cell line. METHODS: We evaluated the underlying mechanisms of the anti-tumor effects of the GABAergic system, such as the involvement of different signaling pathways, apoptosis, and cell cycle arrest, in the high-grade chondrosarcoma cell line OUMS-27. In addition, we performed whole-cell patch-clamp recordings for Ca2+ currents and evaluated the changes in intracellular Ca2+ concentration via Ca2+ channels, which are related to the GABAB receptor in high-grade chondrosarcoma cells. RESULTS: The GABAB receptor antagonist CGP had anti-tumor effects on high-grade chondrosarcoma cells in a dose-dependent manner. The activities of caspase 3 and caspase 9 were significantly elevated in CGP-treated cells compared to in untreated cells. The activity of caspase 8 did not differ significantly between untreated cells and CGP-treated cells. However, caspase 8 tended to be up-regulated in CGP-treated cells. The GABAB receptor antagonist exhibited anti-tumor effects at the G1/S cell cycle checkpoint and induced apoptosis via dual inhibition of the PI3/Akt/mTOR and MAPK signaling pathways. Furthermore, the changes in intracellular Ca2+ via GABAB receptor-related Ca2+ channels inhibited the proliferation of high-grade chondrosarcoma cells by inducing and modulating apoptotic pathways. CONCLUSIONS: The GABAB receptor antagonist may improve the prognosis of high-grade chondrosarcoma by exerting anti-tumor effects via different signaling pathways, apoptosis, cell cycle arrest, and Ca2+ channels in high-grade chondrosarcoma cells.

Doxycycline and its quaternary ammonium derivative for adjuvant therapies of chondrosarcoma.

PURPOSE: This study was conducted during the development of innovative treatment targeting the microenvironment of chondrosarcoma. In this context, MMP inhibitors were conjugated with a quaternary ammonium (QA) function as a targeting ligand to proteoglycans of chondrosarcoma extracellular matrix. Here we report the proof of concept of this strategy applied to the MMP13 inhibitor, doxycycline (Dox). METHODS: A quaternary ammonium derivative of the MMP13 inhibitor doxycycline (QA-Dox) was synthesized, and its anticancer activity was evaluated in the Swarm rat chondrosarcoma (SRC) model compared with the parent drug doxycycline, in vitro and in vivo. In vivo, dox and QA-Dox efficiency was assessed at equimolar doses according to a q4dx4 schedule by monitoring tumour volume by MRI and PG-targeted scintigraphy. Molecular mechanism (MMP13 expression, proteoglycan level) and histology studies were performed on tumours. RESULTS: The link of QA targeting function to Dox maintained the MMP13 inhibitory activity in vitro. Interestingly, the bacteriostatic activity was lost. SRC cells incubated with both drugs were blocked in S and G2 M phases. Tumour growth inhibition (confirmed by histology) was observed for both Dox and QA-Dox. Undesirable blood effects (leukocyte decrease) were reduced when Dox was targeted to tumour tissue using the QA function. CONCLUSIONS: In the SRC model, the MMP13 inhibitor Dox and its QA derivative are promising as adjuvant therapies for chondrosarcoma management.

Andrographolide Induces Cell Cycle Arrest and Apoptosis of Chondrosarcoma by Targeting TCF-1/SOX9 Axis.

Chondrosarcoma is the second most malignant bone tumor with poor prognosis and limited treatment options. Thus, development of more effective treatments has become urgent. Recently, natural compounds derived from medicinal plants have emerged as promising therapeutic options via targeting multiple key cellular molecules. Andrographolide (Andro) is such a compound, which has previously been shown to induce cell cycle arrest and apoptosis in several human cancers. However, the molecular mechanism through which Andro exerts its anti-cancer effect on chondrosarcoma remains to be elucidated. In the present study, we showed that Andro-induced G2/M cell cycle arrest of chondrosarcoma by fine-tuning the expressions of several cell cycle regulators such as p21, p27, and Cyclins, and that prolonged treatment of cells with Andro caused pronounced cell apoptosis. Remarkably, we found that SOX9 was highly expressed in poor-differentiated chondrosarcoma, and that knockdown of SOX9 suppressed chondrosarcoma cell growth. Further, our results showed that Andro dose-dependently down-regulated SOX9 expression in chondrosarcoma cells. Concomitantly, an inhibition of T cell factor 1 (TCF-1) mRNA expression and an enhancement of TCF-1 protein degradation by Andro were observed. In contrast, the expression and subcellular localization of ß-catenin were not altered upon the treatment of Andro, suggesting that ß-catenin might not function as the primary target of Andro. Additionally, we provided evidence that there was a mutual regulation between TCF-1 and SOX9 in chondrosarcoma cells. In conclusion, these results highlight the potential therapeutic effects of Andro in treatment of chondrosarcoma via targeting the TCF-1/SOX9 axis. J. Cell. Biochem. 118: 4575-4586, 2017. © 2017 Wiley Periodicals, Inc.

Aberrant DNA methylations in chondrosarcoma.

Chondrosarcoma (CS) is the second most common primary malignant bone tumor. Unlike other bone tumors, CS is highly resistant to conventional chemotherapy and radiotherapy, thus resulting in poor patient outcomes. There is an urgent need to establish alternative therapies for CS. However, the etiology and pathogenesis of CS still remain elusive. Recently, DNA methylation-associated epigenetic changes have been found to play a pivotal role in the initiation and development of human cancers, including CS, by regulating target gene expression in different cellular pathways. Elucidating the mechanisms of DNA methylation alteration may provide biomarkers for diagnosis and prognosis, as well as novel treatment options for CS. We have conducted a critical review to summarize the evidence regarding aberrant DNA methylation patterns as diagnostic biomarkers, predictors of progression and potential treatment strategies in CS.

Proteoglycans as Target for an Innovative Therapeutic Approach in Chondrosarcoma: Preclinical Proof of Concept.

To date, surgery remains the only option for the treatment of chondrosarcoma, which is radio- and chemoresistant due in part to its large extracellular matrix (ECM) and poor vascularity. In case of unresectable locally advanced or metastatic diseases with a poor prognosis, improving the management of chondrosarcoma still remains a challenge. Our team developed an attractive approach of improvement of the therapeutic index of chemotherapy by targeting proteoglycan (PG)-rich tissues using a quaternary ammonium (QA) function conjugated to melphalan (Mel). First of all, we demonstrated the crucial role of the QA carrier for binding to aggrecan by surface plasmon resonance. In the orthotopic model of Swarm rat chondrosarcoma, an in vivo biodistribution study of Mel and its QA derivative (Mel-QA), radiolabeled with tritium, showed rapid radioactivity accumulation in healthy cartilaginous tissues and tumor after [3H]-Mel-QA injection. The higher T/M ratio of the QA derivative suggests some advantage of QA-active targeting of chondrosarcoma. The antitumoral effects were characterized by tumor volume assessment, in vivo 99mTc-NTP 15-5 scintigraphic imaging of PGs, 1H-HRMAS NMR spectroscopy, and histology. The conjugation of a QA function to Mel did not hamper its in vivo efficiency and strongly improved the tolerability of Mel leading to a significant decrease of side effects (hematologic analyses and body weight monitoring). Thus, QA conjugation leads to a significant improvement of the therapeutic index, which is essential in oncology and enable repeated cycles of chemotherapy in patients with chondrosarcoma. Mol Cancer Ther; 15(11); 2575-85. ©2016 AACR.