Role of cancer stem cells in the development of giant cell tumor of bone.

The primary bone tumor is usually observed in adolescence age group which has been shown to be part of nearly 20% of the sarcomas known today. Giant cell tumor of bone (GCTB) can be benign as well as malignant tumor which exhibits localized dynamism and is usually associated with the end point of a long bone. Giant cell tumor (GCT) involves mononuclear stromal cells which proliferate at a high rate, multinucleated giant cells and stromal cells are equally present in this type of tumor. Cancer stem cells (CSCs) have been confirmed to play a potential role in the development of GCT. Cancer stem cell-based microRNAs have been shown to contribute to a greater extent in giant cell tumor of bone. CSCs and microRNAs present in the tumors specifically are a great concern today which need in-depth knowledge as well as advanced techniques to treat the bone cancer effectively. In this review, we attempted to summarize the role played by cancer stem cells involving certain important molecules/factors such as; Mesenchymal Stem Cells (MSCs), miRNAs and signaling mechanism such as; mTOR/PI3K-AKT, towards the formation of giant cell tumor of bone, in order to get an insight regarding various effective strategies and research advancements to obtain adequate knowledge related to CSCs which may help to focus on highly effective treatment procedures for bone tumors.

Microtubule actin cross-linking factor 1, a novel potential target in cancer.

Cancer is a polygenic disease characterized by uncontrolled growth of normal body cells, deregulation of the cell cycle as well as resistance to apoptosis. The spectraplakin protein microtubule actin cross-linking factor 1 (MACF1) plays an essential function in various cellular processes, including cell proliferation, migration, signaling transduction and embryo development. MACF1 is also involved in processes such as metastatic invasion in which cytoskeleton organization is a critical element that contributes to tumor progression in various human cancers. Aberrant expression of MACF1 initiates the tumor cell proliferation, and migration and metastasis in numerous cancers, such as breast cancer, colon cancer, lung cancer and glioblastoma. In this review, we summarized the current knowledge of MACF1 and its critical role in different human cancers. This will be helpful for researchers to investigate the novel functional role of MACF1 in human cancers and as a potential target to enhance the efficacy of therapeutic treatment modalities.

Structure Prediction: New Insights into Decrypting Long Noncoding RNAs.

Long noncoding RNAs (lncRNAs), which form a diverse class of RNAs, remain the least understood type of noncoding RNAs in terms of their nature and identification. Emerging evidence has revealed that a small number of newly discovered lncRNAs perform important and complex biological functions such as dosage compensation, chromatin regulation, genomic imprinting, and nuclear organization. However, understanding the wide range of functions of lncRNAs related to various processes of cellular networks remains a great experimental challenge. Structural versatility is critical for RNAs to perform various functions and provides new insights into probing the functions of lncRNAs. In recent years, the computational method of RNA structure prediction has been developed to analyze the structure of lncRNAs. This novel methodology has provided basic but indispensable information for the rapid, large-scale and in-depth research of lncRNAs. This review focuses on mainstream RNA structure prediction methods at the secondary and tertiary levels to offer an additional approach to investigating the functions of lncRNAs.

Vertebral column resection for complex congenital kyphoscoliosis and type I split spinal cord malformation.

INTRODUCTION: Congenital progressive kyphoscoliosis associated with split spinal cord malformation (SSCM) is a very rare disease. METHODS AND RESULTS: Here, we present the case of a 23-year-old woman who was found kyphoscoliosis when she was 10 years old and developed rapidly. Thereafter, no management was proposed before her consultation at our center. On examination, numbness was found in the right low limbs, kyphoscoliosis was detected in thoracolumbar, the trunk deviated to the right on standing view and curvature of the thoracolumbar spine was left-sided, the left rib hump was severe and there was little muscle tissue felt under the right side paravertebral area, the pelvis was oblique with the right side higher than the left side, the right arcus costarum was 5 cm below the right iliac crest. One-stage corrective surgery was determined, at first, halo-wheelchair traction gradually with increased traction weights out of hospital for a month; then, after a reasonable correction achieved without any neurological deficits. The one-stage operation was taken through single posterior segmental pedicle screw instrumented fusion with VCR between T12 and L1. Post-operative recovery was uneventful and there were no complications, she was discharged 10 days post operation. At 2 years follow-up, the patient's outcome is excellent with balance and correction of the deformity. CONCLUSION: Based on the Grand Round case and relevant literature, we discuss the different options for the treatment of congenital kyphoscoliosis associated with type I SSCM. In the patient whose kyphoscoliosis is severe and rigid, we recommend an initial release followed by halo-wheelchair traction gradually to correct the deformity, once optimal correction acquires during the traction, the posterior instrumented fusion with VCR upper the bony spur could be done safely without the resection of bony spur.

Induction of apoptosis through caspase-independent or caspase-9-dependent pathway in mouse and human osteosarcoma cells by a new nitroxyl spin-labeled derivative of podophyllotoxin.

Previous study has found that a new nitroxyl spin-labeled derivative of podophyllotoxin, 4-[4"-(2",2",6",6"-tetramethyl-1"-piperidinyloxy)amino]-4'-demethyl-epipodophyllotoxin (GP7), can induce apoptosis in human leukemia cells. However, there have been no studies about the effects of GP7 on osteosarcoma (OS) cells. Here, we observed the anti-OS effects of GP7 in mouse and human OS cells with the comparison of etoposide. GP7 and etoposide inhibited the proliferation of a panel of mouse and human OS cells in a concentration- or time-dependent manner, and the inhibitory effect of GP7 on the proliferation of mouse LM8 or human U2OS cells was 1.28- or 1.35-fold higher than that of etoposide. GP7 or etoposide augmented the anti-OS effects of methotrexate, adriamycin, cisplatin, or their combination, and the combined inhibitory effects of GP7 with MTX on the proliferation of LM8 cells was higher than those of etoposide with MTX. GP7 arrested the cell cycle in S phase but etoposide in G(2)/M phase. GP7 or etoposide induced sub-G(1) peak, apoptotic DNA fragmentation, activations of caspase-3, -8, -9, and DNA fragmentation factor, downregulation of Bcl-2 and Bcl-xL, upregulation of Bax and Bak, and cytochrome-c release from mitochondria in both mouse and human OS cells. GP7 or etoposide also induced endonuclease G translocation from mitochondria into cytosol in mouse cells. GP7- or etoposide-induced apoptotic DNA fragmentation of human OS cells was inhibited by the pan caspase inhibitor and caspase-9 inhibitor, not by caspase-8 inhibitor whereas it was not inhibited by the pan caspase inhibitor in mouse OS cells. Our findings indicate that GP7 is effective against mouse and human OS cells in vitro. The apoptotic DNA fragmentation in mouse OS cells may be mediated by caspase-independent pathway with the involvement of endonuclease G whereas in human OS cells by caspase-9-dependent pathway downstream of the cytochrome-c-initiated caspase cascade.

Identification of Key Genes and Pathways in Osteosarcoma by Bioinformatics Analysis.

PURPOSE: Osteosarcoma (OS) is the most primary bone malignant tumor in adolescents. Although the treatment of OS has made great progress, patients' prognosis remains poor due to tumor invasion and metastasis. MATERIALS AND METHODS: We downloaded the expression profile GSE12865 from the Gene Expression Omnibus database. We screened differential expressed genes (DEGs) by making use of the R limma software package. Based on Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Gene Set Enrichment Analysis, we performed the function and pathway enrichment analyses. Then, we constructed a Protein-Protein Interaction network and screened hub genes through the Search Tool for the Retrieval of Interacting Genes. RESULT: By analyzing the gene expression profile GSE12865, we obtained 703 OS-related DEGs, which contained 166 genes upregulated and 537 genes downregulated. The DEGs were primarily abundant in ribosome, cell adhesion molecules, ubiquitin-ubiquitin ligase activity, and p53 signaling pathway. The hub genes of OS were KDR, CDH5, CD34, CDC42, RBX1, POLR2C, PPP2CA, and RPS2 through PPI network analysis. Finally, GSEA analysis showed that cell adhesion molecules, chemokine signal pathway, transendothelial migration, and focal adhesion were associated with OS. CONCLUSION: In this study, through analyzing microarray technology and bioinformatics analysis, the hub genes and pathways about OS are identified, and the new molecular mechanism of OS is clarified.

LncRNA-zinc finger protein 281 downregulates rho-associated coiled-coil containing protein kinase 1 by upregulating miR-144 in osteosarcoma.

Zinc finger protein 281 (ZNF281) has been characterized as a tumor suppressive lncRNA in glioma. The present study aimed to analyze the functionality of ZNF281 in osteosarcoma (OS). It was demonstrated that ZNF281 was downregulated in OS tissue specimens and predicted the survival of patients with OS. In tissues from patients with OS, ZNF281 was negatively associated with rho-associated coiled-coil containing protein kinase 1 (ROCK1), but positively associated with miR-144. In the U2OS cell line, ZNF281 overexpression mediated the upregulation of miR-44 and downregulation of ROCK1. miR-144 overexpression led to the downregulation of ROCK1, but failed to affect ZNF281. Expression of ZNF281 and miR-144 resulted in decreased cell migration and invasion, while ROCK1 overexpression resulted in increased invasion and migration of OS cells. In addition, ROCK1 overexpression attenuated the effects of ZNF281 and miR-144 overexpression. Thus, ZNF281 may downregulate ROCK1 by upregulating miR-144 and inhibit cancer cell invasion and migration in OS.

Circulating miR-181c-5p and miR-497-5p Are Potential Biomarkers for Prognosis and Diagnosis of Osteoporosis.

CONTEXT: Osteoporosis is a degenerative bone disease in aging men and women. MiRNAs associated with progressive bone loss in osteoporosis had not been clearly demonstrated. OBJECTIVE: The evaluation of the differentially expressed miRNAs in the bone tissue and serum of osteoporotic women with aging. METHODS: MiRNAs GeneChip and real-time PCR were used to screen differently expressed miRNAs in bone tissues of 21 osteoporotic women ages 60-69 years and 80-89 years. Identified miRNAs were detected in the serum of the validation cohort, which consisted of 14 healthy premenopausal women and 86 postmenopausal women with osteopenia or osteoporosis. MiR-181c-5p and miR-497-5p expression were validated in aging and OVX mice models, and osteoblasts. Their role in osteogenesis was validated in vitro. RESULTS: Twenty-four miRNAs showed the highest differential expression in bone tissues of osteoporotic women in initial screening. Among them, four miRNAs were identified both in the bone tissue and serum in the validation cohort. The levels of miR-181c-5p and miR-497-5p were decreased in the serum of postmenopausal women with osteopenia or osteoporosis, but increased in subjects treated with bisphosphonate plus calcitriol. MiR-181c-5p and miR-497-5p were significantly downregulated in the bone tissue of aging and OVX mice models, and upregulated during the osteogenic differentiation of hFOB1.19 and MC3T3-E1 cells. Overexpression of miR-181c-5p and miR-497-5p promoted the differentiation and mineralization of osteoblasts. CONCLUSIONS: MiR-181c-5p and miR-497-5p are involved in bone metabolism and associated with progressive bone loss of due to osteoporosis, suggesting that circulating miR-181c-5p and miR-497-5p might act as potential biomarkers for monitoring the effects of antiosteoporotic therapies or the diagnostic approach.

SDF-1/CXCR4 axis facilitates myeloid-derived suppressor cells accumulation in osteosarcoma microenvironment and blunts the response to anti-PD-1 therapy.

Immune checkpoint inhibitors, such as anti-PD-1/PD-L1, are a novel class of inhibitors that function as a tumor suppressing factor via modulation of immune cell-tumor cell interaction. To date, PD-1/PD-L1 inhibitors have been approved for the treatment of specific types of tumors and obtained good clinical efficacy. However, patients with osteosarcoma showed poor response to anti-PD-1/PD-L1 therapy, the mechanism of which is not well understood. In this study, we found that osteosarcoma tissues were heavily infiltrated by myeloid-derived suppressor cells (MDSCs) which could inhibit cytotoxicity T cell (CTL) expansion. Further study revealed that the vast majority of tumor-infiltrating MDSCs were CXCR4 positive and could migrate toward an SDF-1 gradient. The binding of SDF-1 to its receptor CXCR4 results in the activation of downstream AKT pathway that mediates reduced apoptosis of MDSCs. We also demonstrated that AMD3100, a CXCR4 antagonist, has a synergistic effect with anti-PD-1 antibody in tumor treatment in a murine model of osteosarcoma. These findings provide the basis for establishing CXCR4 antagonist and PD-1/PD-L1 inhibitors co-administration as a novel therapeutic regimen for patients with osteosarcoma and hold great promise for improving the therapeutic effect of osteosarcoma.

Anti-osteosarcoma effects and mechanisms of 4-O-amino-phenol-4'-demethylepipodophyllotoxin ether.

The purpose of this study was to investigate the anti-osteosarcoma effects and mechanisms of 4-O-amino-phenol-4'-demethylepipodophyllotoxin ether (ODE), a new derivative of podophyllotoxin. The results showed that ODE inhibited proliferation of K562, OS-9901, CNE, BGC-823 and Tca-8113 cells in a time- and concentration-dependent manner as determined by microculture tetrazolium (MTT) assay. OS-9901 and K562 cells treated with ODE for 24 h showed cell cycle arrest at G(2)/M and a parallel decrease in G(0)/G(1) and S phase as detected by flow cytometry (FCM). Meanwhile, a fraction of cells with hypodiploid DNA content representing apoptosis were detected by FCM. Morphology observation also revealed typical apoptotic features, including shrinkage of cellular and nuclear membranes, condensed heterochromatin around the nuclear periphery and cytoplasmic vacuolation in OS-9901 cells. Under a confocal laser scanning microscope, intracellular Ca2+ and Mg2+ concentrations were greatly increased whereas the pH value, mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) were markedly reduced in OS-9901 cells after treatment with ODE. Taken together, these results suggest that the anti-osteosarcoma mechanisms of ODE are attributed to apoptosis through increasing intracellular Ca2+ and Mg2+ concentrations, and reducing pH value, MMP and ROS.

Platelet-rich plasma shows beneficial effects for patients with knee osteoarthritis by suppressing inflammatory factors.

Knee osteoarthritis is a degenerative disease that may develop due ageing, obesity, strain, congenital abnormal joints, joint deformity or trauma. It is caused by many factors, such as degradation of articular cartilage injury, joint edge and subchondral bone hyperplasia of reactivity. Platelet-rich plasma (PRP) is an autologous blood sample that contains highly concentrated platelets and multiple cell growth factors. PRP promotes synovial cell proliferation and differentiation and may recover cartilage morphology. In the present study, the clinical efficacy of PRP was investigated in patients with knee osteoarthritis aged between 18 and 30 years in a phase-III clinical study. Following an 8-week baseline, patients with knee osteoarthritis were randomized into once-weekly, double-blind treatment with PRP (2-14 ml) or placebo groups. The results indicated that patients with osteoarthritis treated with PRP had modulated plasma concentrations of inflammatory factors and pro-angiogenic factors compared with the placebo group. Treatment responses were assessed by median percent reduction in inflammatory and pro-angiogenic factors and these improved with PRP treatment compared with the placebo. Clinical data indicated that PRP alleviated knee osteoarthritis and reduced humoral and cellular immune responses that led to beneficial effects on histological parameters. Inflammation was significantly alleviated in patients receiving PRP compared with the placebo group. The most common treatment-emergent adverse events in the presence of PRP were hypertension and proteinuria. In conclusion, treatment with PRP for patients with knee osteoarthritis presented beneficial effects in alleviating joint inflammation, cartilage destruction and bone damage, and repairing joint tissue. These results suggested that PRP may be a potential therapeutic agent for knee osteoarthritis.

Limethason reduces airway inflammation in a murine model of ovalbumin-induced chronic asthma without causing side effects.

Airway inflammation is the major pathological feature of asthma. Thus, the current therapeutic strategy for asthma is to control inflammation. Limethason, an anti-inflammation drug, is widely used in rheumatoid arthritis treatment. The aim of the present study was to detect the anti-inflammatory effect and side effects of limethason on airways that were sensitized with ovalbumin in a murine model of chronic asthma. In the present study, BALB/c mice were sensitized with ovalbumin. Airway hyperresponsiveness was estimated, and hematoxylin and eosin staining, Periodic acid-Schiff staining and bronchoalveolar lavage were used to detect the effect on chronic asthma. Limethason effectively reduced airway hyperresponsiveness, and inhibited inflammatory cell infiltration and mucus secretion. Bronchoalveolar lavage fluid analysis revealed that limethason suppressed levels of airway eosinophils. In the period of treatment, limethason exhibited no influence on morphology of the femoral head, bone mineral content or bone mineral density, which were detected by histological studies and dual-energy X-ray absorptiometry. The index of liver, spleen, kidney, gastrocnemius and brown adipose tissue also demonstrated that limethason had no adverse effects on organs and tissues. The present study revealed that limethason could effectively reduce inflammation in an asthma mouse model without side effects. Therefore, limethason may have therapeutic potential for treating chronic asthma clinically.

Strategies to identify natural antisense transcripts.

Natural antisense transcripts, originally considered as transcriptional noises arising from so-called "junk DNA″, are recently recognized as important modulators for gene regulation. They are prevalent in nearly all realms of life and have been found to modulate gene expression positively or negatively. By affecting almost all stages of gene expression range from pre-transcriptional, transcriptional and post-transcriptional to translation, NATs are fundamentally involved in various biological processes. However, compared to increasing huge data from transcriptional analysis especially high-throughput sequencing technologies (such as RNA-seq), limited functional NATs (around 70) are so far reported, which hinder our advanced comprehensive understanding for this field. Hence, efficient strategies for identifying NATs are urgently desired. In this review, we discussed the current strategies for identifying NATs, with a focus on the advantages, disadvantages, and applications of methods isolating functional NATs. Moreover, publicly available databases for NATs were also discussed.

Isoforms, structures, and functions of versatile spectraplakin MACF1.

Spectraplakins are crucially important communicators, linking cytoskeletal components to each other and cellular junctions. Microtubule actin crosslinking factor 1 (MACF1), also known as actin crosslinking family 7 (ACF7), is a member of the spectraplakin family. It is expressed in numerous tissues and cells as one extensively studied spectraplakin. MACF1 has several isoforms with unique structures and well-known function to be able to crosslink F-actin and microtubules. MACF1 is one versatile spectraplakin with various functions in cell processes, embryo development, tissue-specific functions, and human diseases. The importance of MACF1 has become more apparent in recent years. Here, we summarize the current knowledge on the presence and function of MACF1 and provide perspectives on future research of MACF1 based on our studies and others.

Surgical treatment of fibrous dysplasia in the proximal femur.

The aim of this study was to summarize oncological and functional results and to investigate surgical treatment methods and efficacies by conducting a retrospective study of patients with fibrous dysplasia (FD) in the proximal femur. A total of 15 patients with FD in the proximal femur were selected. Among them, 12 cases were monostotic and 3 cases were polyostotic. In addition, 2 cases were accompanied by shepherd's crook deformity. All cases received internal fixation following focus curettage and impaction grafting. Among them, valgus osteotomy was conducted for 2 cases of shepherd's crook deformity. All patients were followed up for 12-32 months. For 2 patients with shepherd's crook deformity in the proximal femur, the collodiaphysial angle was recovered after an orthopedic procedure following osteotomy. In addition, no patient presented with postoperative recurrent lesions. At 3 months following surgery, local bone resorption was visible in the bone grafting area. Between 8 and 12 months after surgery, the bones in the bone grafting area had healed, pain had disappeared and gaits were nearly normal. An effective internal fixation following thorough focus curettage and allograft bone transplantation is an effective method of treating FD in the proximal femur. For patients with shepherd's crook deformity, it is also necessary to perform valgus osteotomy to recover hip joint function.

[Surgical treatment of fibrous dysplasia in proximal femur].

OBJECTIVE: To summarize the oncological and functional results of patients with fibrous dysplasia in the proximal femur and explore its clinical effect. METHODS: From Apr. 2007 to Jan. 2009, 15 patients with fibrous dysplasia in proximal femur were treated. There were 9 males and 6 females, ranging in age from 16 to 32 years with an average of 25 years. The course of disease was from 2 months to 16 years with an average of 2 years. Among them, 12 cases were unilateral affection and 3 cases were hibateral affections; 12 cases were one bone and 3 cases more than two bones. The collodiaphyseal angles of 2 cases with coxa adducta was 80 degrees and 100 degrees respectively; and femur lengths were shorter than opposite side (5 cm and 3 cm, respectively). The curettage and allogenous and/or autogenous bone-grafting combined with internal fixation were performed in all patients and valgus osteotomies was performed in 2 case with shepherd's crook deformity. RESULTS: All patients were followed up from 12 to 32 months. Two cases with shepherd's crook deformity, the collodiaphyseal angles recovered after surgery, the relative length of femur was increased 4 cm and 3 cm respectively and they can walk with stick at 4 months after operation. No found recurrence and loosening of internal fixation. Bone graft was absorbed at 3 months and bone healing at 8-12 months after operation. The pain vanished and functions were normal. CONCLUSION: It is an effective method to treat fibrous dysplasia in proximal femur with curettage and bone-grafting combined with internal fixation. Corrective osteotomy and internal fixation with a dynamic hip screw is a good and effective method in treating severe symptomatic shepherd's crook deformity.

[Study of inducing bone marrow-derived mesenchymal stem cells into chondrocytes in vitro].

OBJECTIVE: To explore a method of isolation, culture and chondrogenic phenotype differentiation of mesenchymal stem cell (MSCs) from the bone marrow of rats in vitro and to offer experimental reference for the resources of seeding cells in cartilage tissue engineering. METHODS: MSCs were isolated from bone marrow and purified by density gradient centrifuge and cultured in vitro. The MSC adherence formed and those in passage 3 were chosen to induce into chondrogenic differentiation. After 7, 14, 21 days, immunohistochemical techique was applied to detect the expression of collagen type II. The differentiated cells were implanted on the CPP/PLLA composites. After the cell-scaffold complex was cultured in vitro for one week, the ultrastructure of the scaffold was observed with scanning electron microscopy. RESULTS: The differentiated cells changed from a spindle-like fibroblastic appearance to a polygonal shape, the capability of proliferation was down markedly. Immunohistochemical staining of collagen II were positive for the pass age, especially in the 21st days. Induced MSCs were well adherent to the scaffold composites and the cells were embedded by the cell-matrix. CONCLUSION: Under the induced medium, MSCs can differentiate into chondrogenic phenotype and secrete specificity matrix of cartilage in vitro. MSCs can likely be served as optimal cell source for cartilage tissue engineering.