EZH2/hSULF1 axis mediates receptor tyrosine kinase signaling to shape cartilage tumor progression.

Chondrosarcomas are primary cancers of cartilaginous tissue and capable of alteration to highly aggressive, metastatic, and treatment-refractory states, leading to a poor prognosis with a five-year survival rate at 11 months for dedifferentiated subtype. At present, the surgical resection of chondrosarcoma is the only effective treatment, and no other treatment options including targeted therapies, conventional chemotherapies, or immunotherapies are available for these patients. Here, we identify a signal pathway way involving EZH2/SULF1/cMET axis that contributes to malignancy of chondrosarcoma and provides a potential therapeutic option for the disease. A non-biased chromatin immunoprecipitation sequence, cDNA microarray analysis, and validation of chondrosarcoma cell lines identified sulfatase 1 (SULF1) as the top EZH2-targeted gene to regulate chondrosarcoma progression. Overexpressed EZH2 resulted in downregulation of SULF1 in chondrosarcoma cell lines, which in turn activated cMET pathway. Pharmaceutical inhibition of cMET or genetically silenced cMET pathway significantly retards the chondrosarcoma growth and extends mice survival. The regulation of EZH2/SULF1/cMET axis were further validated in patient samples with chondrosarcoma. The results not only established a signal pathway promoting malignancy of chondrosarcoma but also provided a therapeutic potential for further development of effective target therapy to treat chondrosarcoma.

The therapeutic effect of aucubin-supplemented hyaluronic acid on interleukin-1beta-stimulated human articular chondrocytes.

BACKGROUND: Injection of exogenous hyaluronic acid (HA) into the joint capsule improves symptoms of early stage osteoarthritis (OA). However, reactive oxygen species degrade HA into small oligosaccharides that can elicit pro-inflammatory responses. Likewise, disturbance of the antioxidant enzyme system and generation of oxidative stress by pro-inflammatory cytokines worsen knee OA. Accordingly, we proposed the use of aucubin, an antioxidant and anti-inflammatory compound, as a versatile adjuvant to HA for treating OA. METHODS: Primary human chondrocytes were cultured in media supplemented with aucubin in a series of concentrations (0, 0.01, 0.1, 1, and 10 µg/ml) to study dose-dependent toxicity. We then evaluated the therapeutic effects of HA (100 µg/ml) supplemented with aucubin (10 µg/ml) on interleukin-1 beta (IL-1ß, 10 ng/ml)-stimulated chondrocytes. RESULTS: The use of aucubin did not change cell viability or alter lactate dehydrogenase release to normal chondrocytes. Although the proliferation and sulfated glycosaminoglycan production were not affected, aucubin partially restored the hypertrophic transformation of chondrocytes. Relative to treatment with HA or aucubin alone, real-time PCR revealed that aucubin-supplemented HA down-regulated the mRNA levels of tumor necrosis factor-alpha (TNF-α), corrected collagen type 1 and aggrecan, and up-regulated tissue inhibitor of metalloproteinase 1. Moreover, ELISA testing also showed a reduced TNF-α production. Although superoxide dismutases activity was still distributed, aucubin restored total antioxidant capacity of IL-1ß-stimulated chondrocytes. Western blotting further showed that aucubin inhibited cyclooxygenase-2 and regulated the nuclear factor (erythroid-derived 2)-like 2 pathway. CONCLUSION: Aucubin can enhance the anti-catabolic and anti-inflammatory effects of HA on OA chondrocytes.

Synergistic effect of l-ascorbic acid and hyaluronic acid on the expressions of matrix metalloproteinase-3 and -9 in human chondrocytes.

Proinflammatory cytokines and reactive oxygen species (ROS) are known to be involved in the initiation and progression of osteoarthritis (OA). New evidence clarifying the correlation between ROS and inflammation has indicated that oxidative stress can up-regulate inflammatory cytokines. l-Ascorbic acid (AA), an antioxidant, has been shown to have anti-inflammatory effects and improve matrix deposition in chondrocytes. The purpose of this study was to examine the effects of hyaluronic acid (HA; 100 µg/mL) supplemented with AA (50 µg/mL) on human normal and interleukin-1 beta-stimulated (IL-1ß, 10 ng/mL) chondrocytes. HA, AA, and HA + AA treatment did not change cell morphology, viability, proliferation, and glycosaminoglycan production in normal chondrocytes. HA, AA, and HA + AA, by contrast, partially restored viability and morphology of hypertrophic chondrocytes, and HA and HA + AA further decreased the cytotoxicity of IL-1ß. Real-time PCR revealed that AA and HA + AA had no substantial effects on unstimulated chondrocytes, except for down-regulation of matrix metalloproteinase (MMP)-9 mRNA levels. For IL-1ß-stimulated chondrocytes, significant down-regulation of IL-1ß, tumor necrosis factor-alpha (TNF-α), MMP-3, and MMP-9 mRNA expression was found when cells were cultured in HA-supplemented media. Moreover, HA + AA supplementation further significantly decreased MMP-3 and MMP-9 mRNA expression. The protein production of MMP-3 was decreased, with a significant difference between the HA + AA group and HA group. The antioxidant capacity and superoxide dismutases activity were also partially restored in stimulated chondrocytes. HA supplemented with AA modulates MMPs expression and antioxidant fuction in chondrocytes. AA may enhance the anticatabolic effects of HA on OA chondrocytes. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1809-1817, 2018.

Reliability of Roentgenographic Knee Alignment Measurements in Gonarthrosis.

A reliable method of measuring knee alignment is critical in the preoperative planning of high tibial osteotomy (HTO). This radiological study, based on the measurements of the mechanical and anatomical axes of the lower limb, aimed to determine which method would be more reliable and reproducible. From 2004 to 2013, 50 consecutive patients (50 knees) with medial gonarthrosis were treated with valgus-producing HTO. Four independent investigators assessed preoperative standing lower limb radiography (including hip, knee, and ankle joints) to measure both anatomical and mechanical axes. We defined a response as a difference in the angle measured by the same investigator using the same method. The covariates were the investigators and methods. To account for both inter- and intraobserver variabilities, all data were evaluated using a generalized estimating equation model. The results revealed that the effect of the investigators was not statistically significant; however, the effect of the measurement method was highly significant (p < 0.0001). The estimated coefficient of the anatomical axis method was negative, indicating that the reproducibility of the anatomical axis method was better than that of the mechanical axis.

Effects of Different Concentrations of Collagenous Peptide from Fish Scales on Osteoblast Proliferation and Osteoclast Resorption.

The incidence of osteoporosis has increased among the elderly population. Establishing a model of bone remodeling for screening new drugs is critical to identify safe and effective treatments for osteoporosis. In this study, we established a platform to investigate the therapeutic effects of collagenous peptides extracted from scales of two kinds of fish, namely, sparidae and chanos. These peptides were prepared using seven concentrations of collagenous peptide: 100, 80, 60, 40, 20, 10 and 1 mg/ml. Experimental results indicated that collagenous peptides promoted the proliferation of osteoblasts and inhibited the proliferation of mature osteoclasts; the effective concentration of collagenous peptide-sparidae was 10 mg/ml and that of collagenous peptide-chanos was 40 mg/ml. These findings demonstrate that, to a certain extent, collagenous peptides extracted from fish scales can be used to prevent osteoporosis to assist bone remodeling.

l-Glutathione enhances antioxidant capacity of hyaluronic acid and modulates expression of pro-inflammatory cytokines in human fibroblast-like synoviocytes.

Intra-articular injection of hyaluronic acid (HA) has been widely accepted for the treatment of osteoarthritis (OA) in early stage. l-Glutathione (GSH), an antioxidant, has an anti-inflammatory effect on protecting cells from reactive oxygen species and reactive nitrogen species (ROS/RNS). In this study, the therapeutic effects of HA (0.1%) supplemented with GSH (0, 5, 10, and 20% in weight ratios to HA) on human fibroblast-like synoviocytes (FLSs) were evaluated. The results showed that cell morphology and glycosaminoglycan production of FLSs were not changed under treatments. However, the addition of HA + 20% GSH significantly decreased cell survival (p < 0.001) relative to other groups. Relative to un-stimulated FLSs, interleukin-1 beta (IL-1ß) stimulation significantly decreased the total antioxidant capacity (p < 0.001) of cells. The antioxidant capacity was restored and the intracellular ROS/RNS was decreased in HA or HA + GSH-treated FLSs. Real-time PCR analysis revealed the mRNA levels of IL-1ß, tumor necrosis factor-alpha, and matrix metalloproteinase-3 were down-regulated significantly (all p < 0.05) when FLSs cultured in HA or HA + GSH. IL-6 mRNA expressions were down-regulated significantly in HA and HA + 5% GSH groups (both p < 0.05) but up-regulated when HA supplemented with 10% and 20% GSH (both p < 0.01). In addition, the protein levels of IL-1ß were further decreased with significant differences (both p < 0.05) in the HA + 10% GSH and HA + 20% GSH groups when compared to FLSs cultured in normal medium. In conclusion, HA supplemented with GSH improves antioxidant capacity and modulates pro-inflammatory cytokines expressions in FLSs. GSH has the potential to augment the effect of viscosupplementation using HA on OA patients. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2071-2079, 2016.

A Minimally Invasive Endoscopic Surgery for Infectious Spondylodiscitis of the Thoracic and Upper Lumbar Spine in Immunocompromised Patients.

This study evaluates the safety and effectiveness of computed tomography- (CT-) assisted endoscopic surgery in the treatment of infectious spondylodiscitis of the thoracic and upper lumbar spine in immunocompromised patients. From October 2006 to March 2014, a total of 41 patients with infectious spondylodiscitis underwent percutaneous endoscopic surgery under local anesthesia, and 13 lesions from 13 patients on the thoracic or upper lumbar spine were selected for evaluation. A CT-guided catheter was placed before percutaneous endoscopic surgery as a guide to avoid injury to visceral organs, major vessels, and the spinal cord. All 13 patients had quick pain relief after endoscopic surgery without complications. The bacterial culture rate was 77%. Inflammatory parameters returned to normal after adequate antibiotic treatment. Postoperative radiographs showed no significant kyphotic deformity when compared with preoperative films. As of the last follow-up visit, no recurrent infections were noted. Traditional transthoracic or diaphragmatic surgery with or without posterior instrumentation is associated with high rates of morbidity and mortality, especially in elderly patients, patients with multiple comorbidities, or immunocompromised patients. Percutaneous endoscopic surgery assisted by a CT-guided catheter provides a safe and effective alternative treatment for infectious spondylodiscitis of the thoracic and upper lumbar spine.

Incidence of subsequent hip fractures is significantly increased within the first month after distal radius fracture in patients older than 60 years.

BACKGROUND: Distal radius fracture is recognized as an osteoporosis-related fracture in aged population. If another osteoporosis-related fracture occurs in a short period, it represents a prolonged hospitalization and a considerable economic burden to the society.We evaluated the relationship between distal radius fracture and subsequent hip fracture within 1 year, especially in the critical time and age. METHODS: We identified newly diagnosed distal radius fracture patients in 2000 to 2006 as an exposed cohort (N = 9,986). A comparison cohort (N = 81,227) was randomly selected from patients without distal radius fracture in the same year of exposed cohort. The subjects were followed up for 1 year since the recruited date.We compared the sociodemographic factors between two cohorts.Furthermore, the time interval following the previous distal radial fracture and the incidence of subsequent hip fracture was studied in detail. RESULTS: The incidence of hip fracture within 1 year increased with age in both cohorts. The risk was 5.67 times (84.6 vs. 14.9 per 10,000 person-years) greater in the distal radial fracture cohort than in the comparison cohort. The multivariate Cox proportional hazard regression analyses showed the hazard ratios of hip fracture in relation to distal radial fracture was 3.45 (95% confidence interval = 2.59-4.61). The highest incidence was within the first month after distal radial fracture, 17-fold higher than the comparison cohort (17.9 vs. 1.05 per 10,000). Among comorbidities, age 9 60 years was also a significant factor associated with hip fracture (hazard ratio = 8.67, 95% confidence interval = 4.51-16.7). CONCLUSIONS: Patients with distal radius fracture and age 960 years will significantly increase the incidence of subsequent hip fracture, especially within the first month. LEVEL OF EVIDENCE: Prognostic/epidemiologic study, level II.

Stress analysis of glenoid component in design of reverse shoulder prosthesis using finite element method.

BACKGROUND: This study aims to clarify the effect of various designs of reverse shoulder prosthesis (RSP) on stress variation of its glenoid component using 2-dimensional (2D) finite element analysis (FEA). This FEA study provides future reference for the optimal design of glenoid component of RSP. MATERIALS AND METHODS: In this study, a 2D finite element (FE) model of human shoulder with implementation of RSP was developed by commercial FE software. The proper material properties were adopted in our model. Various design factors were simulated and all the mechanical profile data were investigated by FEA. RESULTS: Both distal placement and increased lateral offset of glenosphere induce higher stress over glenoid-baseplate junction. Increased thickness of graft, inferiorly tilting of the baseplate, and adoption of BIO-RSA (bony increased-offset reverse shoulder arthroplasty) incur higher stresses over glenoid screws. The inferior screw attains more stress than superior screw. Maximum stress occurs at the base of inferior screw. CONCLUSION: Increased eccentric offset and lateral offset of glenosphere, although being able to reduce notching, may pay the penalty of significant stress concentration over glenoid and its subsequent loosening. Maximum stress occurs at the base of inferior screw elucidate the direct contact failure mode at the middle of inferior screw. This study provides an alternative tool for the optimal design of glenoid component of RSP in the future.

Hyaluronan up-regulates IL-10 expression in fibroblast-like synoviocytes from patients with tibia plateau fracture.

Progression to osteoarthritis (OA) is a frequent sequela of severe articular fracture, particularly when weight-bearing joints are involved. Prevention from post-traumatic OA remains a challenge. Hyaluronan (HA) therapy is reported to represent a safe and effective treatment for patients with OA and rheumatoid arthritis. However, the capacity of HA to prevent the occurrence of osteoarthritic changes in fractured joints has not been demonstrated. The present study was undertaken to examine the effects of HA on expression of six OA-related proteins in fibroblast-like synoviocytes (FLS) from 10 patients with tibia plateau fracture. OA-related factors were quantified using a sandwich enzyme-linked immunosorbent assay. Regardless of induction of the FLS with interleukin (IL)-1ß, HA was found to down-regulate expression of catabolic factors (IL-1ß, matrix metalloproteinase-3, and tumor necrosis factor-α) and to up-regulate production of anti-catabolic factors (tissue inhibitors of metalloproteinase-1 and metalloproteinase-2). HA also enhanced expression of IL-10, an anti-inflammatory cytokine, in FLS. Our results indicated that HA can promote the expression of both antiinflammatory and structure-protective factors in FLS of patients with tibia plateau fracture.

Effect of different molecular weight hyaluronans on osteoarthritis-related protein production in fibroblast-like synoviocytes from patients with tibia plateau fracture.

BACKGROUND: Preventing arthritic change in a joint with an intra-articular fracture remains a challenge, especially in weight-bearing joints. Hyaluronan (HA) has been proven to be effective in relieving joint pain and improving function in chronic osteoarthritis. However, controversy still exists about its potential use in a joint with an intra-articular fracture and about whether this effect is dependent on molecular weight. We analyzed and compared the effects of two different molecular weight HAs on six osteoarthritis-related proteins expressed in fibroblast-like synoviocytes from 12 patients with tibial plateau fracture. METHODS: The interleukin (IL)-1beta-stimulated or IL-1beta-unstimulated fibroblast-like synoviocytes were cultivated with or without treatment by two different molecular weight HAs. The production of these proteins was quantified by using commercially available sandwich enzyme-linked immunosorbent assay. RESULTS: The results revealed that HA with a high molecular weight is more effective in downregulating proinflammatory cytokines such as interleukin-1beta and tumor necrosis factor-alpha. Conversely, HA with a low molecular weight has greater efficacy in upregulating anticatabolic enzymes, such as tissue inhibitor of metalloproteinase-1 and tissue inhibitor of metalloproteinase-2, and in suppressing the catabolic enzyme, matrix metalloproteinase-3, which are thought to be more chondroprotective. CONCLUSIONS: In a knee joint with an intra-articular fracture of the tibial plateau, we posit that high molecular weight HA may have a better anti-inflammatory effect, whereas low molecular weight HA has superior efficacy for chondroprotection.

Comparison between F-18-FDG positron emission tomography and histology for the assessment of tumor necrosis rates in primary osteosarcoma.

BACKGROUND: The purpose of this prospective study was to identify if F-18-fluorodeoxy-D-glucose positron emission tomography (F-18-FDG PET) was a reliable noninvasive surrogate of histologic response in determining the efficacy of neoadjuvant chemotherapy before surgical resection in primary osteosarcoma. METHODS: Between January 2003 and December 2003, 10 patients with primary osteosarcomas were examined using F-18-FDG PET before neoadjuvant chemotherapy and surgery. The mean age at the time of first intervention was 19 years (range, 4-47 years). Positive prognostic significance was defined as more than 90% tumor necrosis response following neoadjuvant chemotherapy. The parameters of FDG uptake were correlated with histologic findings. The intraclass correlation coefficient was used to validate the tumor necrosis rates determined by PET and histology. RESULTS: The tumor necrosis rate determined by PET was comparable with that determined histologically. The mean standardized uptake value before and following neoadjuvant chemotherapy were 8.2 and 4.4, respectively. The average tumor necrosis rate determined by PET was 22%. However, the mean tumor necrosis rate determined histologically was 54.5%. According to the intraclass correlation coefficient models, the intraclass correlation coefficient equaled O. The relationship of tumor necrosis rates determined by F-18-FDG PET and histology seems to be statistically insignificant. CONCLUSION: In this preliminary study, FDG PET did not seem to be a promising tool for evaluating the response of primary osteosarcoma to neoadjuvant chemotherapy.

Operative treatment of intra-articular distal radius fractures using the small AO external fixation device.

BACKGROUND: A retrospective group study was done to evaluate the effect of the small AO external fixator in the management of acute intra-articular fractures of the distal radius. METHODS: Between January 1995 and December 1996, 70 consecutive patients with articular fractures of the distal radius were treated by closed reduction and external fixation with small AO external fixators. The mean age at the time of surgery was 58.9 years (range, 14-87 years). There were 58 Colles' Barton's fractures and 12 Smith's Barton's fractures. The follow-up period was 104 months (range, 92-118 months). RESULTS: All fractures united in a mean of 5.8 weeks (range, 4-10 weeks). At the final follow-up, the average range of motion was 56.3 +/- 11.6 degrees in flexion, 58.6 +/- 10.7 degrees in extension, 21.5 +/- 4.2 degrees in ulnar deviation, 9.1 +/- 2.9 degrees in radial deviation, 71.5 +/- 8.5 degrees in pronation, and 67.3 +/- 9.2 degrees in supination. Compared with the normal side, the average grip force was 87 +/- 6%. The overall clinical and functional outcomes, according to the scoring system of Gartland and Werley, showed that 22 patients (31.4%) had excellent results, 36 (51.4%) had good results, 9 (12.9%) had fair results, and 3 (4.3%) had poor results. CONCLUSION: Closed reduction and external fixation with the small AO external fixator is useful and effective in the management of displaced comminuted articular fractures of the distal radius.

Allograft arthrodesis of the knee in high-grade osteosarcoma.

BACKGROUND: A retrospective cohort study was conducted to evaluate the outcomes of massive allograft arthrodesis in the management of high-grade osteosarcoma around the knee. METHODS: The results of 19 patients with high-grade osteosarcoma around the knee, which was treated by wide resection and reconstruction using allograft arthrodesis, were evaluated for a mean length of 7.3 years (range, 3-13 years). The mean age at the time of surgery was 13.3 years (range, 6-27 years). According to the Musculoskeletal Tumor Society staging system, 17 patients were stage IIB and 2 were stage IIIB at presentation. Evaluations were based on the oncologic results, non-oncologic results and complications. Functional evaluation was performed with the Enneking functional evaluation form. RESULTS: Four patients (21.1%) died of their disease; 3 (15.8%) are alive with disease; and 12 (63.2%) are free of disease. Four patients (21.1%) had local recurrence of their tumor at a mean of 23 months postoperatively (range, 9-44 months). The mean time to union of the metaphyseal junction was 24.7 weeks (range, 16-30 weeks) and the diaphyseal junction was 47 weeks (range, 24-78 weeks). The overall complication rate was 31.6%, including 2 (10.5%) infections, 3 (15.8%) allograft fractures, and 1 (5.3%) nonunion. Our mean final functional result was 65%. CONCLUSION: Due to the high rate of complications in this study, we conclude that allograft arthrodesis should be left as a salvage or "back-up" reconstructive procedure after resection of osteosarcoma around the knee, unless there are special indications for this procedure. We found allograft fracture to be the most common complication.

Huge aneurysmal bone cyst of iliac bone in a mid-aged female.

Aneurysmal bone cyst is a rare nonneoplastic expansile osteolytic bone lesion of unknown etiology. It usually occurs in the first 2 decades of life. The most common sites are the metaphysio-epiphyseal areas of long bones or vertebrae with eccentric expansion. We present a 42-year-old female with a huge aneurysmal bone cyst of the pelvis with dumbbell-shaped expansion on the both side of the iliac bone, which grew rapidly in 6 months. We also review the literature and discuss its prevalence, clinicopathologic characteristics, differential diagnostic problems, optimal treatment, and the potential of recurrence.