CircUSP48 promotes malignant behavior by regulating CYR61 via miR-365 in osteosarcoma.

Even though circular RNAs (circRNAs), a class of non-coding endogenous RNA, play a crucial role in the progression of osteosarcoma (OS), the specific function of hsa_circ_0000028 (circUSP48) remains unclear. This study aims to elucidate the mechanism by which circUSP48 regulates OS. We employed qRT-PCR and western blot techniques to quantify circDOCK1, miR-186, and DNMT3A levels. Cell proliferation was assessed using the cell counting kit-8 (CCK-8), 5-Ethynyl-20-deoxyuridine (EdU) assay, and colony formation assay. Cell migration and invasion were evaluated through Transwell and cell scratch assays. Furthermore, we performed dual-luciferase reporter, RIP, and RNA pull-down assays to investigate the association between circUSP48, miR-365, and CYR61. In addition, an in vivo xenograft model was utilized to assess the functional role of circUSP48. High levels of circUSP48 and CYR61 were observed in OS tissues and cells, while miR-365 levels were low. Knockdown of circUSP48 suppressed the multiplication, motility, and invasion of OS cells, thereby reducing carcinoma growth. Moreover, inhibition of miR-365 reversed the OS cell-suppressive effect caused by circUSP48 knockdown through direct interaction with circUSP48. Additionally, circUSP48 upregulated the expression of CYR61 by sponging miR-365. The findings suggest that circUSP48 promotes malignant behavior in OS by regulating the expression of CYR61 through miR-365, making it a potential therapeutic target for OS.

A patient with femoral osteitis fibrosa cystica mimicking bone neoplasm: a case report.

BACKGROUND: Osteitis fibrosa cystica is a rare, benign and osteolytic lesion attributed to hyperparathyroidism. The high level of parathyroid hormone cause rapid bone loss. CASE PRESENTATION: The patient is a 50-year-old male complaining of severe and persistent pain in the right knee joint. Imaging studies were suspicious for a benign tumor in the right distal femur. Biopsy under CT guidance showed numerous osteoclast aggregation and hemosiderin deposition around the bone trabeculae. Blood tests disclosed significantly elevated parathyroid hormone, serum calcium, serum alkaline phosphatase. Parathyroid ultrasonography and CT scan showed a solid mass in front of the trachea at the thoracic entrance plane. After resection of the mass, the clinical symptoms were relieved and the radiological results were significantly improved, which further confirmed the diagnosis. CONCLUSIONS: Metabolic diseases-associated bone lesions require a comprehensive diagnosis of multiple inspection items. An interprofessional team approach to the diagnosis and treatment of osteitis fibrosa cystica will provide the best outcome.

MiR-135b promotes proliferation and invasion of osteosarcoma cells via targeting FOXO1.

Recent data strongly suggest the important role of miRNAs in various cancer-related processes. Osteosarcoma (OS) is the most common primary cancer of the bone and usually leads to deaths due to its rapid proliferation and metastasis. Here, we demonstrated that compared with noncancerous bone tissues, miR-135b expression is frequently upregulated in OS specimens, inversely correlated with potential target-FOXO1 expression pattern. Bioinformatics analysis combined with experimental confirmation revealed FOXO1 is a direct target of miR-135b in OS. Functionally, miR-135b inhibitor significantly inhibited OS cells proliferation and invasion. Forced expression of FOXO1 showed the opposite effect, and FOXO1 knockdown abolished the effect of miR-135b inhibitor. Taken together, our data provide compelling evidence that miR-135b functions as an onco-miRNA in OS to promote OS cells proliferation and invasion, and its oncogenic effects are mediated chiefly through targeting FOXO1.

Long non-coding RNA HAND2-AS1 targets glucose metabolism and inhibits cancer cell proliferation in osteosarcoma.

Long non-coding RNA heart and neural crest derivatives expressed 2-antisense RNA 1 (lncRNA HAND2-AS1) is a known tumor suppressor gene in endometrioid endometrial carcinoma; however, its function in osteosarcoma is currently unknown. In the present study, HAND2-AS1 expression in the tumor tissues and adjacent healthy tissues of patients with osteosarcoma, and in the serum of patients and heathy controls was detected by reverse transcription-quantitative polymerase chain reaction. lncRNA HAND2-AS1 small interfering RNA was transfected into osteosarcoma cells, and cell proliferation, glucose transporter 1 (GLUT1) expression and glucose uptake were detected using the Cell Counting Kit-8, western blotting and glucose uptake assays, respectively. The results revealed that the expression levels of HAND2-AS1 were reduced in cancer tissues compared with those in healthy tissues. Levels of HAND2-AS1 were also reduced in the serum of patients with osteosarcoma compared with those of the control subjects. A significant association was observed between serum levels of HAND2-AS1 and tumor size, but not tumor metastasis. HAND2-AS1-knockdown promoted osteosarcoma cell proliferation, increased glucose uptake and upregulated GLUT1 expression. It was therefore concluded that lncRNA HAND2-AS1 may inhibit the proliferation of osteosarcoma cells by targeting glucose metabolism.

EPEL promotes the migration and invasion of osteosarcoma cells by upregulating ROCK1.

E2F-mediated cell proliferation enhancing long non-coding RNA (lncRNA) (EPEL) is a newly identified lncRNA involved in the regulation of lung cancer cell proliferation. However, its association with other types of cancer is unknown. The present study recruited patients with osteosarcoma and healthy controls. Tumor and adjacent healthy tissues were obtained from patients with osteosarcoma, and whole blood was extracted from patients and healthy controls. The expression levels of EPEL in tissues were detected by reverse transcription-quantitative polymerase chain reaction. The diagnostic value of serum EPEL for osteosarcoma was evaluated by receiver operating characteristic curve analysis. The association between serum levels of EPEL and basic clinical patient information was analyzed by χ2 test. Subsequently, EPEL overexpression in osteosarcoma cell lines was established, and its effects on cell migration and invasion were explored by Transwell assay. The implications of EPEL overexpression on Rho-associated coiled-coil containing protein kinase 1 (ROCK1) expression were investigated by western blotting. The results revealed that EPEL was upregulated in tumor tissues compared with adjacent tissues. In addition, serum levels of EPEL were higher in patients with osteosarcoma compared with healthy controls, and were positively associated with distant tumor metastasis. Furthermore, EPEL overexpression promoted the migration and invasion of osteosarcoma cells and induced overexpression of ROCK1. In conclusion, these results suggested that EPEL may promote the migration and invasion of osteosarcoma cells by upregulating ROCK1.

MicroRNA­671­3p regulates the development of knee osteoarthritis by targeting TRAF3 in chondrocytes.

Osteoarthritis (OA) is a degenerative joint disease characterized by articular cartilage degradation and joint inflammation. A previous study showed that microRNA (miR)­671­3p is involved in the development of OA, however, its function and molecular target in chondrocytes during the pathogenesis of OA remain to be fully elucidated. In the present study, miR­671­3p was significantly downregulated in knee OA cartilage tissues compared with normal cartilage tissues. The expression levels of pro­inflammatory cytokines, including interleukin (IL)­1ß, IL­6, IL­8 and tumor necrosis factor (TNF)­α, in the knee OA cartilage tissues were significantly higher than those in the normal cartilage tissues. Through gain­of­function and loss­of­function experiments, miR­671­3p was shown to significantly affect matrix synthesis gene expression, cell proliferation, apoptosis and inflammation in chondrocytes from patients with OA. Subsequent bioinformatics analysis identified potential target sites of the miR­671­3p located in the 3'untranslated region of TNF receptor­associated factor (TRAF3). The results of a dual­luciferase reporter assay showed that TRAF3 is a target gene of miR­671­3p. Western blot analysis demonstrated that miR­671­3p inhibited the gene expression of TRAF3. Furthermore, the restoration of TRAF3 markedly abrogated the effect of miR­671­3p. Taken together, the present study suggests that miR­671­3p may be important in the pathogenesis of OA through targeting TRAF3 and regulating chondrocyte apoptosis and inflammation, which may be a potential molecular target for OA treatment.

miR-29a inhibits adhesion, migration, and invasion of osteosarcoma cells by suppressing CDC42.

Osteosarcoma is one of the most common tumors of the bone in children and adolescents worldwide. The relapse and metastasis of osteosarcoma are a major therapeutic challenge. Recently, several metastasis regulators, including miRNAs, kinases, and lncRNAs, were reported in osteosarcoma. Identifying novel regulators of metastasis will be useful to explore novel biomarkers for osteosarcoma. The present study showed miR-29a overexpression significantly inhibited HOS and MG-63 cell adhesion, invasion, and migration. About 70% of the wound area was repaired by migrating cells after 24 h in the control group, and only 50% of the wound area was repaired in the miR-29a overexpression group. The numbers of invading cells were decreased by 40% and 50% in HOS and MG-63 cells transfected with miR-29a, respectively, compared with the negative control group. Moreover, the present study validated that CDC42 was a direct target of miR-29a in OS cells. In conclusion, miR-29a may serve as a therapeutic target for osteosarcoma.

SUMO-specific protease 2 (SENP2) functions as a tumor suppressor in osteosarcoma via SOX9 degradation.

Osteosarcoma (OS) is the most common primary bone malignancy in children and adolescents, the pathogenesis of which remain largely unknown. Small ubiquitin-like modifier (SUMO)-Specific Protease 2 (SENP2) has been reported to serve as a tumor suppressor in hepatocellular carcinoma cells. The aim of the present study was to investigate the critical role of SENP2 in OS cells. Using reverse transcription-quantitative polymerase chain reaction and western blot assays, it was observed that SENP2 was significantly downregulated in clinical OS tissues compared with adjacent normal samples. Ectopic expression of SENP2 resulted in the suppression of proliferation, migration and invasion in OS cells, whereas SENP2 knockdown by CRISPR-Cas9-based gene editing had the opposite effect. SENP2 is associated with the proteasome-dependent ubiquitination and degradation of SRY-box-9 (SOX9). SOX9 silencing impaired SENP2-depletion-induced accelerated cell growth and migration. Together, these results suggest that SOX9 is a critical downstream effector of the tumor suppressor SENP2 in OS.

Experimental research on ectopic osteogenesis of BMP2-derived peptide P24 combined with PLGA copolymers.

To experimentally evaluate the ectopic osteogenetic capacity of synthesized BMP2-derived peptide P24 combined with poly lactic-co-glycolic acid (PLGA), Wistar rats were divided into two groups: group A, in which BMP2-derived peptide P24/PLGA complex was implanted, and group B which received simple PLGA implant. The complex was respectively implanted into the back muscles of rats. Samples were taken the 1st, 4th, 8th, and the 12th week after the implantation. Their bone formation was detected by X-ray examination, and tissue response was histologically observed. Western blotting was used for the detection of the expression of collagen I (Col-I) and osteopontin (OPN). There was acute inflammation in the tissue around both types of implants at early stage. The cartilage was found around implant areas 4 weeks after the implantation of BMP2-derived peptide p24/PLGA complex, 8 weeks after the implantation, osteoblasts were found, and 12 weeks after the implantation, typical trabecular bone structure was observed. In group B, after 12 weeks, no osteoblasts were found. It is concluded that PLGA is an ideal scaffold material for bone tissue engineering. BMP2-derived peptide can start endochondral ossification and is more effective in inducing ectopic osteogenesis.

[Adhesion, proliferation and osteodifferentiation of bone mesenchymal stem cells on PLGA-[ASP-PEG] tri-bolck polymer scaffolds].

OBJECTIVE: To explore the adhesion,proliferation and osteodifferentiation of bone mesenchymal stem cells (BMSCs)on the prepared lactic acid/glycolic acid/asparagic acid-co-polyethylene glycol(PLGA-[ASP-PEG])tri-block polymer scaffolds. METHODS: Modified PLGA with polyethylene glycol (PEG) and asparagic acid(ASP)that has many liga nds,and then the synthesis PLGA-[ASP-PEG] tri-block polymer material was prepared. BMSCs were cultured in PLGA-[ASP-PEG] polymer material and poly lactic acid-co-glycolic acid(PLGA)were used as control group. Precipitation method, MUT assay and total cellular protein detection were used to test the adhersion and proliferation of BMSCs. After the third generation of BMSCs was cultured on PLGA-[ASP-PEG] tri-block polymer scaffolds for 14 day and 28 day with osteogenic supplements,the osteodifferentiation of MSCs were observed through alkaline phosphatase(ALP) staining and calcium tubercle staining. RESULTS: BMSCs grew adherent to the surface of PLGA-[ASP-PEG] polymer scaffolds and the number of BMSCs was much higher than that of PLGA. The precipitation method suggested that adhesion and proliferation of BMSCs on the surface of PLGA-[ASP-PEG] was much higher than the control group (P < 0.05). MTU assay showed that after BMSCs were cultured for 20 days,the absorbance A of PLGA-[ASP-PEG] polymer scaffolds and PLGA were 1.336 and 0.780 respectively. Total cellular protein could image the adhersion and proliferation of BMSCs indirectly. After BMSCs were cultured for 12 days,the total cellular protein of PLGA-[ASP-PEG] and PLGA were 66.44 microg/pore and 41.23 microg/pore respectively. PLGA-[ASP-PEG] polymer scaffolds had well biocompatibility and cell adhersion. The positive results with ALP staining and calcium tubercle staining in both groups indicated tri-block polymer scaffold and its degradations had no effect on osteodifferentiation. CONCLUSION: PLGA-[ASP-PEG]could improve the adhesion and proliferation of seed cells on bone-matrixmaterial, maintain the morphous of seed cells and had no obvious effect on cell osteodifferentiation.