The SS18-SSX1 fusion gene has been shown to play important roles in the development of synovial sarcoma (SS), but the underlying molecular mechanisms and its downstream target genes are still not clear. Here SHC SH2-domain binding protein 1 (SHCBP1) was identified and validated to be a novel downstream target gene of SS18-SSX1 by using microarray assay, quantitative real-time (qPCR) and western blot. Expression of SHCBP1 was firstly confirmed in SS cell line and SS tissues. The effects of SHCBP1 overexpression or knockdown on SS cell proliferation and tumorigenicity were then studied by cell proliferation, DNA replication, colony formation, flow cytometric assays, and its in vivo tumorigenesis was determined in the nude mice. Meanwhile, the related signaling pathways of SHCBP1 were also examined in SS cells. The results indicated that SHCBP1 was significantly increased in SS cells and SS tissues compared with adjacent noncancerous tissues. The expression of SHCBP1 was demonstrated to be positively correlated with the SS18-SSX1 level. Overexpression and ablation of SHCBP1 promoted and inhibited, respectively, the proliferation and tumorigenicity of SS cells in vitro. SHCBP1 knockdown also significantly inhibited SS cell growth in nude mice, and lowered the MAPK/ERK and PI3K/AKT/mTOR signaling pathways and cyclin D1 expression. Our findings disclose that SHCBP1 is a novel downstream target gene of SS18-SSX1, and demonstrate that the oncogene SS18-SSX1 promotes tumorigenesis by increasing the expression of SHCBP1, which normally acts as a tumor promoting factor.

As a chronic degenerative joint disease, osteoarthritis is among the most common diseases all over the world. In osteoarthritis, inflammation plays an important role in the generation of joint symptoms and the development of disease. When the programmed cell death-1 (PD-1)/programmed death-ligand 1 (PD-L1) immune checkpoint is blocked, the antitumor immunity will be enhanced. We aim to illustrate the function of PD-L1 in osteoarthritis. Osteoarthritis in mice was induced by the injection of collagenase or anterior cruciate ligament transection (ACLT). Anti-PD-L1 was employed to block the signal of PD-L1. Knee joints histological sections were stained by Safranin-O. The level of cytokine was checked by enzyme-linked immunosorbent assay (ELISA) and mRNA level was shown by quantitative reverse transcriptase polymerase chain reaction. The blockade of PD-L1 signal up-regulated inflammatory response and promoted the development of osteoarthritis in mice. The inflammatory cytokine interleukin-6 and tumor necrosis factor-α expression were promoted by PD-L1 blocking in macrophages. Osteoarthritis was aggravated when the expression of inflammatory cytokine is elevated in macrophages. Our results indicated that the blockade of PD-L1 signal in macrophages elevates the expression of inflammatory cytokine and promotes the development of osteoarthritis in mice, which could be utilized as a potential diagnostic and therapeutic target for osteoarthritis patients.

Objective: Osteosarcoma (OS) is the most common malignant bone tumor in children and young adults. Many studies have shown that microRNAs play a critical role in proliferation and metastasis with this tumour type. However, whether aberrant expression might contribute to a metabolism switch in osteosarcoma cases is not clearly understood. In this study, we explored expression and function of miR-150 in osteosarcoma cells. Materials and methods: Expression of miR-150 was assessed by real-time PCR in cell lines and human patient tissues. Scramble siRNA, miR-150 inhibitor, and miR-150 mimics were transfected into osteosarcoma cells to determine their effects on proliferation rate, glucose uptake and lactate secretion. Finally, the relationship between Glut1 and the miR-150 level was explored by luciferase reporter assay and western blotting. Result: miR-150 was consistently decreased in cell lines and osteosarcoma tissues as compared to osteoblast cells and normal bone. Ectopic overexpression of miR-150 inhibited osteosarcoma cell proliferation and suppressed glucose uptake and lactate secretion. Loss of function of miR-150, on the other hand, enhanced osteosarcoma cell proliferation and increased glucose uptake and lactate secretion. Western blot and luciferase reporter assays showed that miR-150 may function by regulating Glut1 expression. Conclusion: These data suggest that miR-150 is involved in regulation of glycolysis in osteosarcoma cells by influencing Glut1 expression.

Our previous findings confirmed that the nerve growth factor-containing fibrin glue membrane provides a good microenvironment for peripheral nerve regeneration; however, the precise mechanism remains unclear. p75 neurotrophin receptor (p75(NTR)) plays an important role in the regulation of peripheral nerve regeneration. We hypothesized that a nerve growth factor-containing fibrin glue membrane can promote neural regeneration by up-regulating p75(NTR) expression. In this study, we used a silicon nerve conduit to bridge a 15 mm-long sciatic nerve defect and injected a mixture of nerve growth factor and fibrin glue at the anastomotic site of the nerve conduit and the sciatic nerve. Through RT-PCR and western blot analysis, nerve growth factor-containing fibrin glue membrane significantly increased p75(NTR) mRNA and protein expression in the Schwann cells at the anastomotic site, in particular at 8 weeks after injection of the nerve growth factor/fibrin glue mixture. These results indicate that nerve growth factor-containing fibrin glue membrane can promote peripheral nerve regeneration by up-regulating p75(NTR) expression in Schwann cells.

Zoledronic acid (ZA) exerts complex influence on bone by suppressing bone resorption, mostly due to the direct osteoclasts inhibition and uncertain influence on osteoblasts. Vitamin K2 (VK2, Menaquinone-4) as an anabolic agent stimulates bone formation via anti-apoptosis in osteoblasts and mild osteoclasts inhibition. Based on these knowledge, the therapeutic effect of the combined or sequential therapy of VK2 and ZA depends on the influence on the osteoblasts, since both cases exert similar inhibitory effect on osteoclasts. In a series of in vitro studies, we confirmed the protective effect of VK2 in osteoblasts culture, especially when followed by exposure to ZA, and the proliferation and mineralization inhibition induced by ZA towards osteoblasts. For mechanism study, expression of bcl-2/bax, Runx2 and Sost in cells were examined. For in vivo studies, an osteoporosis animal model was established in rats via ovariectomy (OVX) and subjected to sequential treatment, namely VK2 followed by ZA. Bone mineral density (BMD) was measured by Dual energy X-ray absorptionmetry (DEXA), morphology and mechanical parameters by micro-computed tomography (micro-CT), mechanical strength by an electro-hydraulic fatigue-testing machine. The bone calcium, hydroxyproline content, blood lipids were evaluated using microplate technique, and the bone surface turnover was evaluated using the fluorescence in corporation method. It was found that VK2 pretreatment partially prevented the inhibition of bone formation caused by ZA, which was reflected by indices like BMD, bone calcium content and bone strength. The underling mechanisms for protection of VK2 pretreatment, mainly demonstrated via in vitro studies, included inhibiting apoptosis and depressing Sost expression in osteoblasts, which in turn improved the osteoporosis therapeutic effects of ZA. These findings suggested that pretreatment with VK2 before ZA therapy might serve a new long-term therapy protocol for osteoporosis.

Our previous studies reported that SHC SH2-domain binding protein 1 (SHCBP1) functions as an oncogene via promoting cell proliferations in synovial sarcoma (SS) cells. However, whether SHCBP1 has any effect on tumor metastasis remains unexplored.

The mainstream lumbar fusion surgeries have various shortcomings, such as complex operation, much invasion, and loss of lumbar function. How to minimize the surgical injury and to achieve better therapeutic effects has become the goal pursued by spine surgeons. This study introduces a cortical bone trajectory (CBT) screw fixation combined with facet fusion (FF), evaluates its safety and efficacy, and explores its advantages, in order to provide a reference for treatment of patients with single-level lumbar stenosis or grade I degenerative spondylolisthesis.

Dysregulation of microRNA-618 (miR-618) has been observed in multiple types of human cancer. However, whether miR-618 is implicated in osteosarcoma (OS) initiation and progression is still unclear. Hence, we measured the expression of miR-618 in OS tissues and cell lines. In addition, the roles of miR-618 and the mechanisms underlying its activities in OS cells were examined.

The neuropeptide Y (NPY) system is considered one of the primary neural signaling pathways. NPY, produced by osteoblasts and other peripheral tissues, is known to inhibit biological functions of osteoblasts. However, until recently, little was known of the autocrine mechanism by which NPY is regulated. To investigate this mechanism, overexpression plasmids and small interfering RNA (siRNA) targeting NPY were transfected into the MC3T3‑E1 cell line to observe its effects on osteogenesis. NPY overexpression was found to markedly enhance the osteogenic ability of MC3T3‑E1 cells by an autocrine mechanism, coincident with the upregulation of osterix and runt‑related transcription factor 2 (Runx2). Furthermore, NPY increased the activities of alkaline phosphatase (ALP) and osteocalcin (OCN) by upregulating their osteoblastic expression in vitro (as well as that of osterix and Runx2). Following transfection with NPY‑siRNA, the osteoblastic ability of MC3T3‑E1 cells was markedly decreased, and NPY deficiency inhibited the protein expression of osterix, Runx2, OCN and ALP in primary osteoblasts. Collectively, these results indicated that NPY played an important role in osteoblast differentiation by regulating the osterix and Runx2 pathways.