CircRNA PVT1 promotes proliferation and chemoresistance of osteosarcoma cells via the miR-24-3p/KLF8 axis.

OBJECTIVE: To investigate the regulatory effect and mechanism of circular RNA PVT1 (circPVT1) in proliferation and chemoresistance of osteosarcoma (OS) cells. METHODS: The expression of circPVT1 in human OS and adjacent normal tissues was detected. The correlation between circPVT1 expression and clinical features of OS was analyzed. The expressions of circPVT1 and miR-24-3p in OS cells resistant to cisplatin, doxorubicin or methotrexate and parental OS cells were detected after cell transfection. CCK-8 and colony formation assay assessed the viability and proliferative ability of OS cells. qRT-PCR and Western blotting measured the expression of KLF8. Dual-luciferase reporter and RNA pull-down assays verified the targeting relationships of circPVT1/miR-24-3p and miR-24-3p/KLF8. RESULTS: CircPVT1 was over-expressed in OS tissues and cells, and correlated with clinical features of OS. Over-expressed circPVT1 reduced the survival of OS patients. CircPVT1 was up-regulated in chemoresistant OS cells compared to their parental cells. CircPVT1 inhibition suppressed the proliferation and chemoresistance of OS cells. MiR-24-3p was under-expressed in OS cells and further down-regulated in chemoresistant cells. CircPVT1 could bind and down-regulate miR-24-3p. MiR-24-3p overexpression inhibited the proliferation and chemoresistance of OS cells. KLF8 was over-expressed in OS cells and further up-regulated in chemoresistant cells. MiR-24-3p negatively regulated the expression of KLF8. CONCLUSION: CircPVT1 mediates proliferation and chemoresistance of OS cells via the miR-24-3p/KLF8 axis. The findings may provide guidance for clinical treatment of OS.

More metalwork removals in patients with olecranon fracture treated by tension band wiring than plate fixation-a propensity score matching analysis.

BACKGROUND: Traditional tension band wiring and plate fixation represent the commonest methods for treating olecranon fractures. However, there is no agreement on which method provides the best outcome. The aim of this retrospective study is to compare the outcomes of tension band wiring (TBW) and plate fixation (PF) for treating displaced olecranon fractures. This is the first study to use propensity score matching analysis to compare treatment methods for olecranon fracture. METHOD: A total of 107 patients aged between 18 and 85 had acute isolated and displaced olecranon fractures. The patients were divided into either TBW (n = 49) or PF (n = 58) groups. To conduct propensity score matching for the treatment method (TBW versus PF), 58 patients were analyzed by logistic regression (29 patients in each group). Various demographic and treatment-related variables were examined and analyzed to determine their correlation. RESULTS: Functional effects between two groups are similar (in terms of Mayo Elbow Performance Score (MEPS), the patients' range of elbow motion (ROM) and forearm rotation (RFR), the time return to work (RTW)). The total adverse events rate and metalwork removal events rate are higher in TBW than that in PF. After propensity score matching analysis, similar primary treatment efficacy (indicated by MEPS> 90) in 2 groups and more primary adverse events (indicated by metalwork removal) were perceived in TBW than that in PF. Logistic regression analysis revealed that fracture type was an independent factor that affected the efficacy of a treatment (regression coefficient = - 1.24 < 0, P = 0.03), indicating that fracture severity was inversely proportional to the efficacy of a treatment for olecranon fracture. Furthermore, logistic regression analysis demonstrated that the treatment method was an independent factor that affected metalwork removal of olecranon fracture (regression coefficient 2.38 > 0, OR = 10.77, P < 0.01), indicating that the risk of metalwork removal in the TBW Group was 10.77 times that in the PF Group. CONCLUSION: When initially discussing the surgical approach with patients, physicians should fully weigh the possibility that TBW may lead to a second surgery due to the higher risk of internal fixation removal and that TBW won't yield better functional outcomes than PF .

Long non-coding RNA ERVK13-1 aggravates osteosarcoma through the involvement of microRNA-873-5p/KLF5 axis.

OBJECTIVE: To explore the effect and mechanism of long noncoding RNA ERVK13-1 on osteosarcoma (OS) cell development by regulation of miR-873-5p/KLF5 axis. METHODS: The expression of ERVK13-1 in the collected tissue was detected by RT-qPCR, and then the relationship between ERVK13-1 expression and clinical characteristics of OS patients was analyzed. After OS cell lines were transfected with miR-873-5p inhibitor, si-ERVK13-1, si-KLF5 or their negative controls, the expression of ERVK13-1, miR-873-5p, and KLF5 in OS cell lines were measured, followed by determination of their effects on cell proliferation, migration, and invasion abilities. Moreover, the binding relationships of ERVK13-1 and miR-873-5p, as well as miR-873-5p and KLF5, were verified by the dual-luciferase reporter gene assay. RESULTS: Highly expressed ERVK13-1 was found in OS tissues, which was closely related to tumor size, tumor node metastasis, and distant metastasis. The overall survival of OS patients with high expression of ERVK13-1 was poorer than those with low expression of ERVK13-1. Elevated ERVK13-1 and KLF5 but suppressed miR-873-5p was observed in the OS cell lines U2OS and MG63. Transfection with miR-873-5p inhibitor enhanced the malignant potentials of OS cells, and transfection with si-ERVK13-1 or si-KLF5 reduced these abilities of OS cells. ERVK13-1 bound to miR-873-5p and KLF5 was a target gene of miR-873-5p. CONCLUSION: The ERVK13-1/miR-873-5p/KLF5 axis confers vital effect on the occurrence and progression of OS, thus providing possible guidance for the clinical treatment of OS.

Circ_0025908 regulates cell vitality and proliferation via miR-137/HIPK2 axis of rheumatic arthritis.

BACKGROUND: Rheumatic arthritis (RA) is an autoimmune disease with bad effects. Recent researches have shown that circular RNAs (circRNAs) could affect the progress of RA, but the mechanism still indistinct. In this work, we explored the roles of circ_0025908 in RA. METHODS: The levels of circ_0025908, microRNA-137 (miR-137), and mRNA of homeodomain-interacting protein kinase 2 (HIPK2) were detected by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) in RA tissues. Meanwhile, the level of HIPK2 was quantified by Western blot analysis. Besides, the cell functions were examined by CCK8 assay, EdU assay, flow cytometry assay, ELISA, and Western blot. Furthermore, the interplay between miR-137 and circ_0025908 or HIPK2 was detected by dual-luciferase reporter assay. RESULTS: The levels of circ_0025908 and HIPK2 were upregulated, and the miR-137 level was decreased in RA tissues in contrast to that in normal tissues. For functional analysis, circ_0025908 deficiency inhibited cell vitality, cell mitotic cycle, cell proliferation, and immunoreaction in RA cells, whereas promoted cell apoptosis. Moreover, miR-137 was confirmed to repress the progression of RA cells by suppressing HIPK2. In mechanism, circ_0025908 acted as a miR-137 sponge to regulate the level of HIPK2. CONCLUSION: Circ_0025908 facilitates the development of RA through increasing HIPK2 expression by regulating miR-137, which also offered an underlying targeted therapy for RA treatment.

miR-129-3p alleviates chondrocyte apoptosis in knee joint fracture-induced osteoarthritis through CPEB1.

BACKGROUND: Osteoarthritis (OA), a refractory disease, is one of the leading contributors for disability worldwide. Since chondrocyte is the only resident cell in cartilage, this study aims to explore the roles of miR-129-3p and CPEB1 in chondrocyte apoptosis in knee joint fracture-induced OA. METHODS: Cartilage was collected from 20 OA patients who underwent total knee replacement (OA group) and 20 patients with knee contusion (normal group). Then, miR-129-3p and CPEB1 levels in the cartilage were quantified by qRT-PCR. Primary rat chondrocytes in the knee were isolated and identified by toluidine blue staining and immunofluorescent staining of type II collagen. OA cellular models were induced by TNF-α treatment, in which miR-129-3p and CPEB1 expressions were assessed. Subsequently, cell viability, apoptosis, and the expression levels of apoptotic protein and caspase-3 were measured. Dual luciferase reporter assay identified the interaction between miR-129-3p and CPEB1. RESULTS: Patients in the OA group had decreased miR-129-3p expression and increased CPEB1 expression than those in the normal group. TNF-α treatment successfully induced the OA cellular model. Downregulated miR-129-3p and upregulated CPEB1 expressions were found in OA-treated chondrocytes. miR-129-3p overexpression or CPEB1 knockdown improved chondrocyte viability and attenuated apoptosis, and vice versa. miR-129-3p negatively regulated CPEB1, thus ameliorating apoptosis and enhancing cell viability. CONCLUSION: miR-129-3p negatively targeted CPEB1 to facilitate chondrocyte viability and hamper apoptosis.

The Glu727 Allele of Thyroid Stimulating Hormone Receptor Gene is Associated with Osteoporosis.

BACKGROUND: Published data indicate that thyroid stimulating hormone receptor (TSHR) activities are associated with osteoporosis in some patients. AIM: This study aimed to elucidate whether a given polymorphism of the TSHR gene is associated with osteoporosis. MATERIALS AND METHODS: One hundred and fifty subjects with osteoporosis were recruited in this study. The diagnosis of osteoporosis was performed with quantitative ultrasound system. The TSHR gene polymorphism was examined by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The results showed a nucleotide substitution in the first position of codon 36 of the TSHR gene. The nucleotide substitution was from G to C, leading to a (36)D → (36)H change (D36H) in the predicted amino acid sequence of the receptor. The change did not show significance between healthy subjects and patients with osteoporosis (P > 0.05). On the other hand, we identified another single nucleotide polymorphism that is a C-to-G substitution at codon 727 (GAC to GAG); its frequency was significantly higher in patients with osteoporosis than that in healthy subjects. Using logistic regression analysis, significant correlation was revealed between the genotype D727E and the serum levels of TSH, or the quantitative ultrasound value of the calcaneal bone. CONCLUSIONS: The present study suggests that the genotype D727E of the TSHR, but not the genotype D36H, may be a genetic risk factor for osteoporosis.