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Programmed osteocyte death might be a pathogenesis of steroid-related avascular necrosis of the femoral head (SANFH). Autophagy-related gene 5 (ATG5) can activate the unfolded protein response pathway under endoplasmic reticulum stress (ERS) to participate in cell regulation, but the regulatory mechanism remains unclear. We examined the role of ERS in SANFH pathogenesis by studying the ATG5 participation mechanism in osteoblast apoptosis regulation to provide a theoretical basis for developing new SANFH therapeutic targets. Rat bone marrow mesenchymal stem cells cultured in vitro underwent osteogenic induction and alizarin red staining. The resultant osteoblasts were divided into Control, SANFH (methylprednisolone-treated), SANFH+ATG5 small interfering RNA (siRNA) (methylprednisolone-treated ATG5 siRNA transfection) groups. Beclin 1, MAP1LC3, ATG5, PERK, and caspase-3, -9, and -12 mRNA and protein expression levels were detected, the osteoblast survival rate was measured, and apoptosis was detected. The relationship between Beclin 1, MAP1LC3, ATG5, PERK, and caspase-3, -9, and -12 mRNA and protein expression levels and osteoblast apoptosis was analyzed. The SANFH group had enhanced expression of the autophagy-related genes Beclin 1 and MAP1LC3 and numerous autophagosomes were formed. Osteoblast injury stimulated ERS. ATG5 siRNA inhibited the glucocorticoid-induced osteoblast autophagy and ERS. The ER stimulated the caspase-12/9/3 cascade through ATG5 to enhance apoptosis and improve persistent ERS. The continuous action of methylprednisolone increased Beclin 1 and MAP1LC3 gene expression, resulting in bone cell injury and stimulating ERS. The ER activated the caspase-12/9/3 cascade via ATG5 under persistent and unchangeable ERS, leading to apoptosis and SANFH.

Background: Osteosarcoma is the most common primary malignant tumor of bone. Abnormal expression of S100A1 protein is closely related to the occurrence and development of malignant tumors. However, S100A1 in osteosarcoma has not been studied. Methods: All osteosarcoma tissues were collected from patients who received surgical therapy at the Affiliated Hospital of Inner Mongolia Medical University, China in 2020. QRT-PCR and western blot assays were used to detect the expression of S100A1 in osteosarcoma tissues and cells. The negative effect of S100A1 on osteosarcoma cell growth was confirmed by vitro and vivo experiments. Results: S100A1 inhibited the growth of osteosarcoma cells in vitro. Overexpression of S100A1 may inhibit the proliferation of osteosarcoma cells by preventing the activation of AKT signaling pathway by western blot assay. Finally, animal experiments confirmed that overexpression of S100A1 could inhibit the proliferation of osteosarcoma cells. Overexpression of S100A1 obtained better survival benefit in mice. Conclusion: Our findings provided a new insight to the treatment of osteosarcoma. It also raised the possibility that S100A1 could be used in targeted therapies for osteosarcoma.

Aims Increasing evidences have suggested that microRNAs (miRNAs) play crucial roles in cancer development and progression. Our previous study showed that the level of miR-217 was remarkably lower in GCT cells and tissues, and the re-expression of miR-217 induced an inhibitory effect on occurrence and development of GCT in vitro. However, the mechanisms underlying the proliferation inhibition effect of miR-217 in GCT cells still remain unknown. Thus, this article is aimed to explore the mechanisms underlying the proliferation inhibition effect of miR-217 in GCT cells. Methods The GCT cells proliferative potential was measured by use of the MTT assay and BrdU straining. The changes in migration and invasion of GCT cells was determined by transwell assay. Finally, western blot and RT-PCR assays were employed to evaluate the expression of OPG/RANKL/RANK signaling pathway related-proteins. Result In the present study, the excessive upregulation of miR-217 markedly suppressed GCT cell proliferation and tumorigenesis in vitro and in vivo. Meanwhile, the overexpression of miR-217 could inhibit OPG/RANKL/RANK signal pathway in vitro and in vivo. Furthermore, the ALP activity was also significantly decreased in GCT cells by miR-217 treatment. Importantly, miR-217 could inhibit autophagy-related protein expression and autophagosomes/autolysosomes formation in GCT cells and tissues. Conclusion These results suggest that the upregulation of miR-217 inhibit the occurrence and development of GCT through inhibiting autophagy. This study also offers an effective therapeutic target to improve the survival rates of patients with CGT in the future.

MicroRNAs (miRNAs) have been considered as a new class of novel diagnostic and predictive biomarker in many diseases. However, there are few studies on miRNA in osteosarcoma (OS). This study aimed to investigate the roles of miR-30 on OS occurrence and development.PCR was used to detect mRNA levels of miR-30 and MTA1 in cancer tissues, adjacent non-cancerous tissues from OS patients. Western blot was used to detect MTA1 protein expression in all tissues and cell lines (hFOb1.19,Saos-2, MG63, and U2OS). The correlation between miR-30 and MTA1 was predicted through bioinformatics software, and identified by a luciferase reporting experiment. In vitro, functional test detected the specific effects of miR-30 and MTA1 on the development of OS.miR-30 expression was significantly reduced, while the expression of MTA1 was increased in OS tissues and cells. Luciferase reporting experiment showed that miR-30 sponged MTA1 which was negatively correlated with miR-30 expression. Furthermore, rescue tests revealed that MTA1 restrained the functions of miR-30 on cell proliferation and migration of OS.Our finding showed that miR-30 modulated the proliferation and migration by targeting MTA1 in OS.

Objective To investigate whether miR‐141 and the sex determination region of Y chromosome box 11 (SOX11) play roles in steroid‐induced avascular necrosis of the femoral head (SANFH), and to explore whether miR‐141 could target SOX11 to influence the proliferation of bone marrow mesenchymal stem cells (BMSC). Methods Bone marrow mesenchymal stem cells (BMSC) were isolated and cultured from 4‐week‐old Sprague Dawley rats. A flow cytometry assay was performed to identify BMSC. BMSC were divided into two groups: a control group and a dexamethasone (DEX) group. BMSC were transfected by miR‐141 mimic, miR‐141 inhibitor, and SOX11. Real‐time polymerase chain reaction (PCR) assay was performed to investigate the mRNA expression of miR‐141 and SOX11. The results were used to determine the effect of transfection and to verify the expression in each group and the association between miR‐141 and SOX11. Luciferase reporter assay revealed the targeted binding site between miR‐141 and the 3′‐untranslated region of SOX11 mRNA. MTT assays were performed to investigate the proliferation of BMSC in the miR‐141 mimic, miR‐141 inhibitor, and SOX11 groups. Result The results of the flow cytometry assay suggested that cells were positive for CD29 and CD90 while negative for CD45. This meant that the isolated and cultured cells were not hematopoietic stem cells. In addition, cell transfection was successful based on the expression of miR‐141 and SOX11. According to the results of real‐time PCR assay, the mRNA expression of miR‐141 in SANFH was upregulated (4.117 ± 0.042 vs 1 ± 0.027, P

Background Osteosarcoma (OS) is a highly malignant tumor. Improving chemotherapeutic resistance is very important to improve the survival rate of OS. Exosomes and microRNAs (MiRNA) play important roles in the mechanism of chemotherapeutic resistance transmission. More and more researches focus the mechanism of miRNAs carried by exosomes in the transmission of chemotherapeutic resistance of OS. This study focused on exploring the mechanism of exosomal miR-331 in the transmission of chemoresistance in OS. Methods We cultured OS drug-resistant cells and extracted exosomes of these cells. The secretion and uptake of exosomes in OS drug-resistant cells and OS cells (OSCs) were confirmed by fluorescence tracking assay and transwell experiments. The differential expression of microRNA-331 (miR-331) in exosomes of OS resistant and OS cells was investigated by RT-PCR. The effects of drug-resistant exosomes on proliferation and migration of OS cells were determined by MTT assay and scratches assay. MDC staining, RT-PCR, and Western blot were used to detect the role of autophagy which regulated by drug-resistant cell-derived exosom-miR-331. Results We found that the expression difference of miR-331 between drug-resistant cells of MG63 and HOS cell lines and tumor cells was the most significant. Drug resistant OSCs secreted exosomes and were ingested by OSCs, which then promoted OSCs to acquire drug resistance. In addition, exosomes secreted by drug-resistant OSCs promote drug resistance by carrying miRNAs. Interestingly, inhibition of miRNA resulted in reduced drug resistance transmission of exosomes. Finally, we found that the exosomes secreted by drug-resistant OSCs could induce autophagy of OSCs by carrying miR-331, thus making OSCs acquire drug resistance. Inhibition of miR-331 can effectively improve drug resistance of OSCs. Conclusions Chemoresistant OSCs-derived exosomes promote the transmission of drug resistance by carrying miR-331 and inducing autophagy. Inhibition of miR-331 could effectively alleviate drug resistance of OSCs.

OBJECTIVE To analyze the effect of microRNA-22 on autophagy and proliferation and to investigate the underlying molecular mechanism of osteosarcoma cell chemotherapy sensitivity. METHODS MG-63 cells were divided into four groups, including a control group, a negative control (NC) group, a cisplatin group, and a cisplatin + miR-22 group. Proliferation of MG-63 cells that had been treated with cisplatin and transfected with miR-22 mimics was determined using MTT assay and colony formation assay. We assessed the degree of autophagy using flow cytometry through cellular staining of the autophagy lysosomal marker monodansylcadaverine (MDC). The effect of microRNA-22 on autophagy was observed along with the expression levels of Beclin1, LC3, metadherin (MTDH) and ATG5 by western blot and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Luciferase reporter assay revealed the targeted binding site between miR-22 and the 3'-untranslated region (3'-UTR) of MTDH mRNA. Western blot and qRT-PCR were used to explore the level of MTDH in the control group, the NC group, the cisplatin group, and the miR-22 group for 6, 12, and 24 h. RESULTS In the in vitro study, the MTT results indicated that the MG-63 cells with overexpression of miR-22 exhibited a significant decline in the proliferation capacity compared with the control group (0.513 ± 0.001, P < 0.0005). Similar to the MTT results, MG-63 cells that were transfected with miR-22 mimic (101.0 ± 10.58) formed fewer colonies compared with the cisplatin group (129.7 ± 4.163). MDC staining revealed that miR-22-overexpressing osteosarcoma (OS) cells treated with cisplatin showed a significant decrease in the expression of autophagy (7.747 ± 0.117, P < 0.0001). Our data revealed that miR-22 could regulate not only autophagy but also proliferation in the chemosensitivity of osteosarcoma cells. We found that miR-22 sensitized osteosarcoma cells to cisplatin treatment by regulating autophagy-related genes. In addition, Luciferase Reporter Assay revealed that miR-22 negatively regulated autophagy through direct targeting of MTDH. We performed western blot analysis to detect the MTDH expression level. The results revealed that the overexpression of miR-22 obviously decreased the expression of MTDH (1.081 ± 0.023, P < 0.001). CONCLUSION Inhibition of miR-22 ameliorated the anticancer drug-induced cell proliferation decrease in osteosarcoma cells. MTDH was identified as the miR-22 target in OS cells and MTDH-triggered autophagy played a key function in the miR-22-associated chemotherapy sensitivity.

Cancer-associated fibroblasts (CAFs) serve as a predominant regulator in the tumor microenvironment. However, the crosstalk between CAFs and OS cells remains mostly unclear. Recent studies explored that long non-coding RNA (LncRNAs) involved in regulating osteosarcoma (OS) formation and development, but their functions in CAFs are unknown. Here, we first investigated the SNHG17 was upregulated in OS tissues and correlated with the poor prognosis through the integrating clinical data. We then evaluated the function of SNHG17 in vitro using the stable SNHG17-depleted OS cells. HOS cells with SNHG17 knocked down were performed to generate the OS xenograft model. Through immunohistochemistry assay and TUNEL apoptosis assay, the role of SNHG17 on OS development was assessed in vivo. We then examined the SNHG17 expression in exosomes derived from CAFs, normal fibroblasts (NFs), and tumor tissues from the OS clinical samples. The interaction among SNHG17, miR-2861, and MMP2 was predicted by bioinformatics analysis and identified by RIP and luciferase assays. The cell proliferation, migration, and apoptosis of SJSA-1 and HOS cells co-cultured with CAFs-derived exosomes were assessed by CCK-8 and colony formation assays. We found that SNHG17 was upregulated in the tumor tissues and presented a pro-tumorigenic effect on OS both in vitro and in vivo. It also was an essential exosomal cargo of CAFs and could affect OS cell proliferation and migration in vitro. CAFs-released exosomal SNHG17 acted as an essential molecular sponge for miR-2861 in OS cells. Moreover, MMP2 was a direct target of miR-2861 and was regulated by SNHG17. Overall, our findings identified that SNHG17 was an essential exosomal cargo of OS-related CAFs that contributes to proliferation and metastasis of OS, supporting the therapeutic potency of targeting the crosstalk between cancer cells and CAFs.

Background The standard treatment for severe displaced pediatric supracondylar humeral fracture (SCHF) is closed reduction and percutaneous pin fixation. However, controversy persists concerning the optimal pin fixation technique. The purpose of this study was to compare the safety and efficacy on the configuration of lateral entry only with crossed entry pin fixation for SCHF, including Gartland type II and type III fractures in children. Methods Published literatures, including retrospective studies, prospective studies, and randomized controlled trials, presenting the probability of poor functional consequence of elbow and/or loss of reduction and/or iatrogenic ulnar nerve injury and/or superficial infection and/or cubitus varus were included. Statistical analysis was performed with the Review Manager 5.3 software. Results Twenty-four studies were included in the present meta-analysis involving 1163 patients with lateral entry pins and 1059 patients with crossed entry pins. An excellent score of Flynn criteria occurred more commonly in patients who treated with crossed pins than in patients with lateral pins only (RR = 0.93; 95% CI 0.87–0.99; P = 0.03). In accordance with previous systematic review, the incidence of iatrogenic ulnar nerve injury in crossed entry group was significantly more than in lateral entry group with statistical difference (RR = 0.26; 95% CI 0.14–0.47; P

// Yuyan Na 1,2,* , Rui Bai 1,* , Zhenqun Zhao 1 , Yishan Wei 1 , Daihe Li 1 , Yong Wang 1 , Chao Sun 1 , Liang Sun 1 , Bolun Zhang 1,2 , Tianbo Jin 3,4 and Wanlin Liu 1 1 Department of Pediatric Orthopedics, The Second Affiliated Hospital of Inner Mongolia Medical University, Hohhot, Inner Mongolia Autonomous Region, China 2 Graduate School of Inner Mongolia Medical University, Hohhot, Inner Mongolia Autonomous Region, China 3 Xi’an Tiangen Precision Medical Institute, Xi’an, Shaanxi, China 4 National Engineering Research Center for Miniaturized Detection Systems, School of Life Sciences, Northwest University, Xi’an, Shaanxi, China * These authors have contributed equally to this work Correspondence to: Wanlin Liu, email: // Tianbo Jin, email: // Keywords : knee OA; IL1R1; genetic polymorphism; case-control study Received : August 11, 2016 Accepted : December 07, 2016 Published : December 14, 2016 Abstract IL1R1 , encoding interleukin 1 receptor type 1, is located in the IL-1 gene cluster and is involved in the pathogenesis of hand, hip, and knee osteoarthritis (OA) in different ethnicities. However, the link between IL1R1 polymorphisms and OA risk in the Chinese Han population is unknown. We studied the association between five IL1R1 polymorphisms (rs10490571, rs12712127, rs956730, rs3917225, and rs3917318) and OA risk by analyzing the genotypes of 298 knee OA patients and 297 controls using Sequenom MassARRAY technology. Logistic regression analysis after adjusting for gender and age revealed significant differences in the allele frequencies of IL1R1 rs956730 and IL1R1 rs3917225 between patients and controls. In addition, IL1R1 rs3917225 was associated with increased risk of knee OA with or without adjustment by age and gender in the dominant model (adjusted OR= 1.47, 95%CI: 1.04-2.07, P = 0.030), the recessive model (adjusted OR= 1.75, 95%CI: 1.08-2.85, P = 0.023), and the additive model (adjusted OR= 1.40, 95%CI: 1.09-1.79, P = 0.007). This study is the first to report that IL1R1 polymorphisms are associated with knee OA susceptibility in the Northwestern Chinese Han population.

Ankylosing spondylitis (AS) is an extreme form of inflammatory arthritis which always leads to bony fusion of vertebral and chronic pain of back. A lot of genes including interleukin, matrix metalloproteinases (MMPs), and endoplasmic reticulum aminopeptidase were found associated with AS. MMP family members were involved in the autoimmune disease and orthopedic diseases such as rheumatoid arthritis and osteoarthritis, while few studies concentrated on the correlation between single-nucleotide polymorphisms (SNPs) in MMP and AS. In addition, there is no report on the relationship between MMP-8 and AS. To investigate the association between SNPs in MMP-8 and AS, we recruited 268 patients with AS and 654 healthy people to conduct a case–control study. Five SNPs including rs3740938, rs2012390, rs1940475, rs11225394, and rs11225395 of MMP-8 gene were genotyped. It was found rs3740938 of MMP-8 was associated with an increased risk of AS under the dominant model and additive model after adjustment for gender and age by performing logistic regression analysis (odds ratio [OR] = 1.49, 95% confidence interval [CI] = 1.02–2.18, P = .038; OR = 1.37, 95% CI = 1.01–1.87, P = .042, respectively). Moreover, haplotype “GGTCA” was associated with an increased risk of AS without adjustment for age and gender (OR = 1.75, 95% CI = 1.05–2.92, P = .032), while no positive result was found after adjustment for age and gender. Based on our results, our study indicates significant association between SNPs of MMP-8 and AS risk in a Chinese Han population and these results provide the first evidence that MMP-8 is correlated with AS.

Apoptosis of osteoblasts, triggered by prolonged or excessive use of glucocorticoids (GCs), has been identified as a dominant contributor to the development of osteoporosis and osteonecrosis. However, the molecular mechanisms underlying GC-induced apoptosis are multifaceted and remain to be fully elucidated. The present study aimed to explore the correlation between dexamethasone (DEX)-induced reactive oxygen species (ROS), autophagy and apoptosis in MC3T3-E1 osteoblast-like cells. Cell viability was assessed using a Cell Counting Kit-8 assay, and flow cytometry was performed to assess cellular apoptosis, cell cycle and ROS production. Immunofluorescence and western blot analysis were respectively used to detect autophagic vacuoles and the expression of proteins, including cyclin D kinase (CDK)2, poly[ADP ribose] polymerase, caspase-3, activating transcription factor (ATF)4, CCAAT/enhancer-binding protein homologous protein (CHOP), Beclin1, microtubule-associated proteins 1A/1B light chain (LC)3B and P62. It was revealed that DEX not only reduced cell viability, but also promoted apoptosis via the activation of endoplasmic reticulum (ER) stress. In addition, DEX induced cell cycle arrest at G0/G1 phase via inhibition of the expression of CDK2, and the production of ROS was activated. Of note, the DEX-mediated changes in viability and apoptosis were attenuated in MC3T3-E1 cells after treatment with 3-methyladenine, which is an autophagy inhibitor. Treatment with the antioxidant N-acetylcysteine abolished the effect of DEX on the proliferation, apoptosis, ER stress and autophagy of MC3T3-E1 cells. In conclusion, the present results indicated that DEX promoted the production of ROS, which enhanced apoptosis through activation of autophagy and ER stress in MC3T3-E1 cells.

Oxidative stress represents a major cause of cellular damage and death in pathological conditions including osteoporosis, in which oxidative stress is associated with increased bone resorption and low bone mass. And grape seed proanthocyanidins are a group of polyphenolic bioflavonoids which are known to possess broad pharmacological activity and therapeutic potential, exerting a protective role against oxidant injury. The aim of our study was to investigate whether proanthocyanidins exert an anti-apoptosis effect in osteoblastic MC3T3-E1 cells, via their antioxidant activity. Firstly, we determined the anti-apoptosis effect of proanthocyanidins in osteoblastic MC3T3-E1 cells, which were subject to H2O2 treatment, then we determined the association of the antioxidant activity exerted by proanthocyanidins with their anti-apoptosis effect. Results demonstrated that proanthocyanidins inhibit H2O2-promoted apoptosis in MC3T3-E1 cells, via ameliorating the viability of MC3T3-E1 cells post H2O2 treatment and reducing the apoptotic cell numbers. And the proanthocyanidins treatment also ameliorates the H2O2-induced mitochondrial dysfunction via promoting the mitochondrial membrane potential (MMP) and respiratory chain complex IV, and reducing the mitochondrial free radical production, ROS and mitochondrial superoxide. Moreover, the proanthocyanidins inhibit H2O2-induced apoptosis signaling which is mediated by p53. This study implied a possible anti-osteoporosis effect of proanthocyanidins via their antioxidant and anti-apoptosis activity.

Cytovillin plays structural and regulatory roles in the assembly and stabilization of specialized plasma membrane domains and in the tumor angiogenesis. Cytovillin expression has been proposed to be an effective biomarker of prognosis in patients with osteosarcoma, and many studies have been performed to assess the prognostic role of cytovillin expression in patients with osteosarcoma. We performed this meta-analysis to provide a comprehensive evaluation of the role of cytovillin expression on the overall survival rate by calculating the pooled risk ratio (RR) with corresponding 95 % confidence interval (95 % CI). Finally, eight studies with a total of 415 patients with osteosarcoma were included into the meta-analysis. Meta-analysis of total eight studies showed that cytovillin expression was obviously associated with lower overall survival rate in patients with osteosarcoma (RR = 0.41, 95 % CI 0.28–0.58, P

Many studies have investigated the associations between methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and risk of fractures, but the impact of MTHFR polymorphisms on fractures risk is unclear owing to the obvious inconsistence among those studies. This study aims to quantify the strength of association between MTHFR C677T and A1298C polymorphisms and risk of fractures. We searched the PubMed, Embase and Wanfang databases for articles relating the association between MTHFR C677T and A1298C polymorphisms and risk of fractures in humans. We estimated summary odds ratios (ORs) with their confidence intervals (CIs) to assess the associations. Meta-analyses suggested MTHFR C677T polymorphism was associated with increased risk of any site fractures (for T vs. C, OR = 1.17, 95 % CI 1.03-1.32; for TT vs. CC, OR = 1. 31, 95 % CI 1.11-1.54; for TT vs. CT, OR = 1.22, 95 % CI 1.04-1.43; for TT vs. CT/CC, OR = 1.31, 95 % CI 1.13-1.51). Besides, MTHFR A1298C polymorphism was also associated with increased risk of any site fractures. Subgroup meta-analyses suggested MTHFR C677T polymorphism was associated with increased risk of vertebral fractures under three genetic contrast modes (for TT vs. CC, OR = 1.43, 95 % CI 1.05-1.95; for TT vs. CT, OR = 1.36, 95 % CI 1.01-1.85; for TT vs. CT/CC, OR = 1.50, 95 % CI 1.17-1.91), but there was no association between MTHFR C677T polymorphism and risk of hip fractures and non-vertebral fractures (all P values were more than 0.05). Thus, individuals with homozygote genotype TT of MTHFR C677T have obviously increased risk of vertebral fractures compared those with heterozygote genotype CT or homozygote genotype CC. There is no association between MTHFR C677T polymorphism and risk of hip fractures and non-vertebral fractures.

Osteonecrosis of the femoral head (ONFH) is a common hip joint disease, and steroid-induced ONFH accounts for a large number of cases. Here, we examined eight previously-identified single-nucleotide polymorphisms (SNPs) in the MPP2 and MPP9 genes of 285 steroid-induced ONFH patients and 507 healthy controls from northern China to determine whether these SNPs were associated with the risk of developing steroid-induced ONFH. Chi-squared tests and genetic model and haplotype analyses were used to evaluate associations. The rs2274755 SNP in MMP9 was associated with a decreased risk of steroid-induced ONFH in the allele, dominant, and additive models. Additionally, the "CGC" MMP9 haplotype was associated with a 0.69-fold decrease in the risk of steroid-induced ONFH. Although additional, larger population-based studies are needed to confirm these findings, our results reveal for the first time an association between a MMP9 SNP at the rs2274755 locus and a decreased risk of steroid-induced ONFH in a northern Chinese population.

An animal model of steroid-induced avascular necrosis of femoral head (SANFH) was established to investigate the role of oxidative DNA damage of bone marrow hematopoietic cells in SANFH. Forty-five-month-old Japanese white rabbits (male or female, 2.5 ± 0.5 kg) were randomly divided into groups A (methylprednisolone + Escherichia coli endotoxin), B (methylprednisolone alone), C (E. coli endotoxin alone), and D (blank control). The animals were sacrificed two and four weeks after administration of the last dose (N = 5 each group and each time). Left and right femoral heads were fixed and decalcified. Empty lacunae were counted by hematoxylin and eosin staining and oxidative DNA damage of bone marrow hematopoietic cells was detected by immunohistochemistry. At week 2, the rate of oxidative DNA damage in bone marrow hematopoietic cells was significantly higher in group A than in groups B, C, and D (P < 0.01), while there was no significant difference between groups B, C, and D. At week 4, the rate of oxidative DNA damage in bone marrow hematopoietic cells was significantly higher in group A than in groups B, C, and D (P < 0.01), while there was no significant difference among groups B, C, and D. Thus, oxidative DNA damage of bone marrow hematopoietic cells appears to play an important role in SANFH.

We aimed to assess whether the five common SNPs can affect the risk of osteosarcoma, and its association with demographic characteristics of osteosarcoma. 165 osteosarcoma patients and 330 cancer-free controls were enrolled into our study. Five common SNPs in VEGF gene, -2578C/A (rs699947), -1156G/A (rs1570360), +1612G/A (rs10434), +936C/T (rs3025039) and -634G/C (rs2010963), were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Conditional logistic regression analyses found that individuals with AA genotype and A allele of rs699947 were associated with an increased risk of osteosarcoma. Individuals with GG genotype and G allele of rs2010963 were associated with an increased risk of osteosarcoma. By stratified analysis, AA genotype of rs699947 was associated with an increased risk of osteosarcoma in those with shorter age, males and a family history of cancer, and GG genotype of rs2010963 was correlated with an increased risk of osteosarcoma in those with shorter age, females and a family history of cancer. Our study suggests that rs699947 and rs2010963 polymorphisms may play a role in the pathogenesis of osteosarcoma.

Oxidative stress represents a major cause of cellular damage and death in pathological conditions including osteoporosis, in which oxidative stress is associated with increased bone resorption and low bone mass. And grape seed proanthocyanidins are a group of polyphenolic bioflavonoids which are known to possess broad pharmacological activity and therapeutic potential, exerting a protective role against oxidant injury. The aim of our study was to investigate whether proanthocyanidins exert an anti-apoptosis effect in osteoblastic MC3T3-E1 cells, via their antioxidant activity. Firstly, we determined the anti-apoptosis effect of proanthocyanidins in osteoblastic MC3T3-E1 cells, which were subject to H2O2 treatment, then we determined the association of the antioxidant activity exerted by proanthocyanidins with their anti-apoptosis effect. Results demonstrated that proanthocyanidins inhibit H2O2-promoted apoptosis in MC3T3-E1 cells, via ameliorating the viability of MC3T3-E1 cells post H2O2 treatment and reducing the apoptotic cell numbers. And the proanthocyanidins treatment also ameliorates the H2O2-induced mitochondrial dysfunction via promoting the mitochondrial membrane potential (MMP) and respiratory chain complex IV, and reducing the mitochondrial free radical production, ROS and mitochondrial superoxide. Moreover, the proanthocyanidins inhibit H2O2-induced apoptosis signaling which is mediated by p53. This study implied a possible anti-osteoporosis effect of proanthocyanidins via their antioxidant and anti-apoptosis activity.

To date, little is known regarding the molecular mechanisms underlying the deregulation of the giant cell tumor of bone (GCTB). Hypoxia has been confirmed to be a characteristic observed in a variety of types of cancer, and a pivotal role for hypoxia‑inducible factor-1α (HIF‑1α) has previously been indicated in the hypoxia adaptation of GCTBs. However, another key regulator, microRNA (miR)‑210, which is closely correlated with HIF‑1α, has not previously been identified in GCTBs. The present study therefore selected miR‑210, the most significantly upregulated miRNA in hypoxic subtypes of cancer, for investigation in GCTB tissues. Reverse transcription-quantitative polymerase chain reaction was used to evaluate miR‑210 expression levels in GCTB tissues and primary GCTB stromal cells. It was revealed that miR‑210 and HIF‑1α were upregulated in GCTB specimens and in primary GCTB stromal cells under hypoxia, and a positive correlation was identified between the two molecules. Furthermore, the promotion of miR‑210 expression in primary GCTB stromal cells by hypoxia was HIF‑1α‑dependent. To the best of our knowledge, the present study was the first to identify the overexpression of miR‑210 in an HIF‑1α‑dependent manner in GCTB specimens, suggesting an adaptive response to hypoxia in GCTB.

Acquisition of drug-resistant phenotypes is often associated with chemotherapy in osteosarcoma. Studies show that high-mobility group box 1 (HMGB1) plays an important role in facilitating autophagy and promotes drug resistance in osteosarcoma cells. In this study, we determined the targeting role of miR-22 to HMGB1 and the regulation of miR-22 on the HMGB1-mediated cell autophagy and on the cell proliferation, migration, and invasion of osteosarcoma cells. Results demonstrated that miR-22 well paired with the 3'-UTR of HMGB1 downregulated the HMGB1 expression and blocked the HMGB1-mediated autophagy during chemotherapy in osteosarcoma cells in vitro. Further study showed that the blockage of autophagy by miR-22 inhibited the osteosarcoma cell proliferation, migration, and invasion. In summary, this study implied the negative regulation of miR-22 on the HMGB1-mediated autophagy in osteosarcoma cells.

Although classified as benign, giant cell tumors of the bone (GCTB) may be aggressive, recur and even metastasize to the lungs. In addition, the pathogenesis and histogenesis remain unclear; thus, the driving factors behind the strong tumor growth capacity of GCTB require investigation. In the present study, the expression levels of hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF), which are promoted by hypoxic conditions, were determined in 22 sacral GCTB samples using immunohistochemistry and western blot analysis. Furthermore, CD34 expression was analyzed using these methods. The correlation between HIF-1α or VEGF expression and the tumor microvessel density (MVD) was then determined. The results demonstrated that HIF-1α, VEGF and CD34 were overexpressed in the 22 sacral GCTB specimens, and overexpression of HIF-1α and VEGF correlated with the tumor MVD. Thus, the present study has provided novel indicators for the tumor growth capacity of GCTBs.