LncRNA ODRUL regulates progression of osteosarcoma by regulating IL-6 via sponging miR-6874-3p.

Accumulating evidence has shown that many long non-coding RNAs (lncRNA) participate in the tumorigenesis, including osteosarcoma (OS). Of them, lncRNA ODRUL was previously reported to act as a possible oncogene in OS doxorubicin resistance. However, the underlying molecular mechanism of ODRUL involved in the progression of OS still remains to be thoroughly investigated. In the current study, we reported another mechanism by which ODRUL regulates OS progression. QRT-PCR and WB were conducted to detect ODRUL, miR-6874-3p and IL-6 expression in OS tissues and cells. The Kaplan-Meier was used to assess the relevance between the expression level of miR-6874-3p and the overall survival of OS patients. Wound healing assays and Transwell assays were used to evaluate the invasion and migration of OS cells. Furthermore, the binding sites of ODRUL and IL-6 to miR-6874-3p were predicted by bioinformatics and verified by dual-luciferase reporter gene assays. ODRUL and IL-6 were highly expressed in OS cells and tissues, while miR-6874-3p was expressed at low levels. The overall survival of high miR-6874-3p expression of OS patients was longer than that of low miR-6874-3p expression of OS patients. MiR-6874-3p overexpression markedly inhibited the progression of OS cells. Both ODRUL and IL-6 could bind to miR-6874-3p at the predicted binding sites which were authenticated by dual-luciferase reporter gene assay. MiR-6874-3p could inhibit OS cell proliferation and metastasis and ODRUL could reverse the suppression induced by miR-6874-3p in vivo. In conclusion, ODRUL could effectively sponge miR-6874-3p to upregulate the expression of IL-6 in OS progression.

Refracture after plate removal of midshaft clavicle fractures after bone union-incidence, risk factors, management and outcomes.

INTRODUCTION: There is a great debate on the routine use of open reduction and internal fixation (ORIF) for midshaft clavicle fractures, and one concern is the adverse events after ORIF, such as implant removal after bone union. In this retrospective study, we assessed the incidence, risk factors, management and outcomes of refracture after plate removal of midshaft clavicle fractures after bone union. MATERIALS AND METHODS: Three hundred fifty-two patients diagnosed with acute midshaft clavicle fractures who had complete medical records from primary fractures to refracture were recruited. Details of imaging materials and clinical characteristics were carefully reviewed and analysed. RESULTS: The incidence rate of refracture was 6.5% (23/352), and the average interval from implant removal to refracture was 25.6 days. Multivariate analysis showed that the risk factors were Robinson type-2B2 and fair/poor reduction. Females were 2.4 times more likely to have refracture, although it was not significant in multivariate analysis (p = 0.134). Postmenopausal females with a short interval (≤ 12 months) from primary surgery to implant removal had a significant risk for refracture. Tobacco use and alcohol use during bone healing were potential risk factors for male patients, although they were not significant in multivariate analysis. Ten patients received reoperation with or without bone graft, and they had a higher rate of bone union than 13 patients who refused reoperation. CONCLUSION: The incidence of refracture following implant removal after bone union is underestimated, and severe comminute fractures and unsatisfactory reduction during primary surgery are risk factors. Implant removal for postmenopausal female patients is not recommended due to a high rate of refracture.

Selenium-doped calcium phosphate biomineral reverses multidrug resistance to enhance bone tumor chemotherapy.

The construction of a functional drug delivery system to reverse the multidrug resistance (MDR) of bone tumors in cases of failed chemotherapy remains a challenge. Herein, we demonstrate a selenium-doped calcium phosphate (Se-CaP) biomineral with high biocompatibility, biodegradability and pH-sensitive drug release properties. Se-CaP may not only serve as an effective drug-carrier to enhance the uptake of doxorubicin (DOX), but may also synchronously induce caspases-mediated apoptosis of osteosarcoma by generating intracellular reactive oxygen species (ROS). Furthermore, in vitro and in vivo studies obviously demonstrate that Se-CaP can reverse the MDR of osteosarcoma by down-regulating the expression of MDR-related ABC (ATP binding cassette) transporters proteins (ABCB1 and ABCC1). Finally, DOX-loaded Se-CaP can significantly inhibit DOX-resistant MG63 (MG63/DXR) tumor growth in nude mice. Considering its biomimetic chemical properties, the Se-CaP biomineral, with the multiple functions mentioned above, could be a promising candidate for treating bone tumors with MDR characteristics.

Doxorubicin-induced novel circRNA_0004674 facilitates osteosarcoma progression and chemoresistance by upregulating MCL1 through miR-142-5p.

Accumulating evidence has shown that circular RNA (circRNA) dysregulation is involved in various types of cancer, including osteosarcoma (OS). Nevertheless, the role and mechanism of circRNAs in OS progression and chemoresistance remain elusive. We found that a novel doxorubicin-induced circular RNA, hsa_circ_0004674, screened by whole total transcriptome RNA sequencing in our previous study, was upregulated in OS chemoresistant cell lines and tissues and also connected with patients' poor prognosis. Circ_0004674 knockdown remarkably suppressed OS cell chemoresistance, proliferation, migration, invasion, OS tumor growth, and enhanced cell cycle arrest and apoptosis in vitro and in vivo through control the expression of the antiapoptotic protein MCL1, a member of the Bcl-2 gene family. Further online bioinformatics analysis revealed that miR-142-5p had potential binding sites that can bind circ_0004674 and the 3'UTR of MCL1 mRNA. Moreover, the expression and function of miR-142-5p were conversely correlated with circ_0004674 in vitro. RIP, pull-down, luciferase assay, and RNA FISH demonstrated that circ_0004674 could compete with MCL1 for miR-142-5p binding to counteract miR-142-5p-mediated repression of MCL1 at the post-transcriptional level. To sum up, our study sheds light on the critical role of the oncogenic circ_0004674/miR-142-5p/MCL1 axis in OS progression and chemoresistance, providing a novel potential target for OS therapy.

Is increased symptom interval associated with advanced stage and poorer outcome? A prospective multicenter study of 220 patients with osteosarcoma around the knee.

OBJECTIVE: Osteosarcoma is rare disease and there is a strong controversy about the potential impact of symptom interval on the stage of disease and patients' outcomes. We want to assess whether increased symptom interval (SI) is associated with advanced tumor stage and poor prognosis for patients with osteosarcoma. METHODS: We analyzed prospectively collected data of 220 patients younger than 40 years who had osteosarcoma around the knee. Symptom interval was analyzed to evaluate its impact on metastases at diagnosis, tumor volume, chemotherapy response and overall survival. RESULTS: The median of SI was 64.5 (Q1-Q3: 42-88) days. The 5-year overall survival rate for patients with different length of symptom interval (<42 days, 42-64 days, 65-87 days, > = 88 days) were 0.78 (95 %CI: 0.67-0.89), 0.49 (95 %CI: 0.35-0.63), 0.52 (95 %CI:0.39-0.65), and 0.65 (95 %CI:0.53-0.77) respectively(p = 0.013). Nonparametric test showed increased SI was associated with metastases at diagnosis (p = 0.008), but not associated with large tumor volume or poor chemotherapy response. Cox regression mode test showed that patient with increased SI had higher hazard ratio (42-64 days HR: 2.586 (95 %CI:1.360-4.915); 65-87 days, HR: 2.225 (95 %CI:1.170-4.233)) for poor outcomes compared to short SI (<42 days), though it was not significant in multivariate analysis (p = 0.182). CONCLUSION: Increased SI but not the longest SI is associated with higher incidence of metastases at diagnosis; patients can benefit from an earlier diagnosis in terms of survival.

Treatment-Related Prognostic Factors in Managing Osteosarcoma around the Knee with Limb Salvage Surgery: A Lesson from a Long-Term Follow-Up Study.

PURPOSE: The aim of this study was to assess the treatment-related factors associated with local recurrence and overall survival of patients with osteosarcoma treated with limb-salvage surgery. PATIENTS AND METHODS: Treatment-related factors were analyzed to evaluate their effects on local recurrence-free survival (LRFS) and overall survival (OS) in 182 patients from 2004 to 2013. RESULTS: The mean length of follow-up was 73.4 ± 34.7 months (median, 68 months; range, 12-173 months), and 63 patients died by the end of the follow-up. The 5-year and 10-year overall survival rates were 68.6 ± 6.6% and 59.4 ± 10.6%, respectively. Univariate analysis showed that treatment-related prognostic factors for overall survival were prolonged symptom intervals >=60 days, biopsy/tumor resection performed by different centers, previous medical history, incomplete preoperative chemotherapy (<8 weeks), and prolonged postoperative interval >21 days. In the multivariate analysis, biopsy/tumor resection performed by different centers, incomplete implementation of planned new adjuvant chemotherapy, and delayed resumption of postoperative chemotherapy (>21 days) were risk factors for poor prognosis; biopsy/tumor resection performed by different centers and tumor necrosis <90% were independent predictors of local recurrence. CONCLUSION: For localized osteosarcoma treated with limb-salvage surgery, it is necessary to optimize timely standard chemotherapy and to resume postoperative chemotherapy to improve survival rates. Biopsies should be performed at experienced institutions in cases of developing local recurrence.