The m6A methyltransferase METTL3 promotes osteosarcoma progression by regulating the m6A level of LEF1.

Osteosarcoma(OS) is the most common and aggressive malignant bone sarcoma,which occurs in rapidly growing bones in children and adolescents. However, the underlying molecular mechanisms of OS development have not been fully illustrated. N6-Methyladenosine (m6A) is the most prevalent internal chemical modification of mRNAs, which is involved in many pathological processes in cancer development. However, its role and regulatory mechanism in OS remain unknown. In this study, we aimed to investigate the roles of m6A and its methyltransferase METTL3 in OS development. The results showed that m6A level for RNA methylation and the expression level of METTL3 were up-regulated in human OS tissues and OS cell lines. Functionally, lentivirus-mediated METTL3 silence in HOS and SAOS-2 cells inhibited the cell proliferation, migration and invasion ability. Further mechanism analysis suggested that METTL3 silence decreased the m6A methylation and total mRNA level of lymphoid enhancer-binding factor 1 (LEF1), followed by inhibited the activity of Wnt/ß-catenin signaling pathway. Moreover, LEF1 over-expression abrogates the repressive effects of METTL3 silence on the proliferation, migration and invasion abilities of OS cells. Together, these results revealed that the m6A methyltransferase METTL3 promotes osteosarcoma cell progression by regulating the m6A level of LEF1 and activating Wnt/ß-catenin signaling pathway.

A Self-Assembled Coumarin-Anchored Dendrimer for Efficient Gene Delivery and Light-Responsive Drug Delivery.

The assembly of low molecular weight polymers into highly efficient and nontoxic nanostructures has broad applicability in gene delivery. In this study, we reported the assembly of coumarin-anchored low generation dendrimers in aqueous solution via hydrophobic interactions. The synthesized material showed significantly improved DNA binding and gene delivery, and minimal toxicity on the transfected cells. Moreover, the coumarin moieties in the assembled nanostructures endow the materials with light-responsive drug delivery behaviors. The coumarin substitutes in the assembled nanostructures were cross-linked with each other upon irradiation at 365 nm, and the cross-linked assemblies were degraded upon further irradiation at 254 nm. As a result, the drug-loaded nanoparticle showed a light-responsive drug release behavior and light-enhanced anticancer activity. The assembled nanoparticle also exhibited a complementary anticancer activity through the codelivery of 5-fluorouracil and a therapeutic gene encoding tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). This study provided a facile strategy to develop light-responsive polymers for the codelivery of therapeutic genes and anticancer drugs.

Resveratrol Attenuates Lipopolysaccharides (LPS)-Induced Inhibition of Osteoblast Differentiation in MC3T3-E1 Cells.

BACKGROUND LPS-inhibited osteoblastic differentiation plays an important role in the pathogenesis of osteomyelitis. Thus, searching for drugs that affect LPS-mediated osteoblastic differentiation may be crucial in developing therapies for osteomyelitis. The purpose of this study was to investigate the role and mechanisms of resveratrol, a natural polyphenol present in red wine, on LPS-inhibited osteoblastic differentiation. MATERIAL AND METHODS Cell viability was measured by MMT assay. Mitochondrial ATP levels, membrane potential, and superoxide production were measured to evaluate the effects of LPS and resveratrol on mitochondrial functions in osteoblast-like MC3T3-E1 cells. Osteoblast-related genes, including ALP, OCN, OPN, and RUNX2, were measured by ELISA analysis and RT-PCR in differentiated osteoblast cells treated with LPS and resveratrol. Cellular Sirt1 and PCG-1α levels were measured by Western blot to probe the impact of resveratrol treatment in LPS-stimulated MC3T3-E1 osteoblasts. RESULTS The results showed that LPS caused significant mitochondrial dysfunctions of MC3T3-E1 cells in a dose-dependent manner, which were attenuated by resveratrol. Furthermore, LPS markedly decreased the expression of ALP, OCN, OPN, and RUNX2 in MC3T3-E1 cells cultivated in osteoblast differentiation medium, suggesting that LPS inhibited the osteoblastic differentiation of MC3T3-E1 cells. However, resveratrol obviously alleviated the suppressive impact of LPS on osteoblast differentiation. In addition, resveratrol increased expression of Sirt1 and PGC-1α in MC3T3-E1 cells treated with LPS. CONCLUSIONS Taken together, these results show that resveratrol alleviated the suppression of LPS on osteoblast differentiation by improving, at least in part, mitochondrial function.

Spine extra-osseous chordoma mimicking neurogenic tumors: report of three cases and review of the literatures.

BACKGROUND: For a long time, chordoma has been known as an osseous tumor mainly found at the clivus and sacrococcygeal region. However, spine extra-osseous chordoma (SEC) with a better prognosis than the classic type has been neglected. According to our literature review, only several case reports have been published in English literatures. Here in this article, three cases of SEC, plus a literature review, are presented. CASE PRESENTATION: Three cases of SEC were presented from our center. Surprisingly, neurologic tumors were considered as the first diagnosis. Thereafter, en bloc resection was performed in all the three cases. Especially, the dumbbell-shaped one in the cervical spine was removed by en bloc through the combined anterior and posterior approach for the first time. Follow-up within 12-58 months after surgeries proved no recurrence or metastasis. CONCLUSIONS: Spine extra-osseous chordoma, commonly located in the cervical and epidural region, is extremely rarely met. SEC is characterized with less aggressiveness, the lower rate of recurrence and metastasis, and better prognosis than those of the osseous origin. Though complete excision can be achieved generally, differential diagnosis of spine neurogenic tumors and the following en bloc resection should be made as carefully as possible.

Mesoporous nanoplatform integrating photothermal effect and enhanced drug delivery to treat breast cancer bone metastasis.

Bone metastatic breast cancer has severely threatened the survival and life quality of patients. Due to the suboptimal efficacy of anti-metastatic chemotherapeutic drugs and the complicated bone marrow microenvironments, effective treatment of metastatic breast cancer remains challenging for traditional clinical approaches. In this work, we developed a mesoporous nanoplatform (m-CuS-PEG) with the co-loading of CuS nanodots and a chemotherapeutic drug cisplatin for the combined photothermal-chemotherapy of bone-metastasized breast cancer. The CuS nanodots were decorated onto mesoporous silica (m-SiO2) surface with dendritic mesoporous channels, into which the cisplatin was accommodated. The carboxyl-terminated poly (ethylene glycol) (PEG) was further functionalized onto the surface to obtain the functional nanoplatform m-CuS-PEG. The drug release of the loaded cisplatin exhibited pH- and thermal-dual responsive manner. The attached CuS nanodots rendered the mesoporous nanoplatform with high photothermal conversion ability. Upon irradiation with a near-infrared laser in the second near-infrared (NIR-II) window, m-CuS-PEG dispersions exhibited rapid temperature elevation and high photostability. The results revealed that m-CuS-PEG had excellent biocompatibility. The cisplatin-loaded m-CuS-PEG not only showed superior cancer cell-killing effects, but also significantly inhibit the growth of metastatic tumors. The tumor-induced bone destruction was also dramatically attenuated by the mesoporous nanoplatform-mediated combined therapy. Overall, the developed functional nanoplatform integrates photothermal therapy and efficient chemotherapeutic drug delivery to offer an alternative approach for combating breast cancer bone metastasis.

LncRNA NR_027471 Functions as a ceRNA for miRNA-8055 Leading to Suppression of Osteosarcoma by Regulating the Expression of TP53INP1.

Osteosarcoma is a malignancy with high aggressiveness and poor prognosis, which occurs mainly in children. The therapeutic strategy against osteosarcoma includes surgery combined with chemotherapy and radiotherapy. Although the treatment of osteosarcoma has been improved in recent years, there is a large proportion of patients with incurable osteosarcoma. Investigation of the mechanism of osteosarcoma progression would be of great help in discovering therapeutic targets for this disease. Long non-coding RNAs play critical roles in the pathogenesis of different types of cancer. The current study showed that long non-coding RNA NR_027471 was downregulated in osteosarcoma cells. In vitro and in vivo studies indicated that upregulation of NR_027471 impeded the viability, proliferation, and invasion of osteosarcoma, as well as induced cell cycle arrest at G1. In addition, binding of miR-8055 to NR_027471 was demonstrated, thereby influencing the expression of tumor protein p53 inducible nuclear protein 1 (TP53INP1). Knockdown of NR_027471 promoted epithelial-mesenchymal transition by inhibiting E-cadherin and increasing the expression of zinc finger E-box-binding homeobox 1 (ZEB1), Snail, and fibronectin. These results suggested that overexpression of NR_027471 upregulated TP53INP1 by sponging to miR-8055, leading to suppression of osteosarcoma cell proliferation and progression.

Prognostic Analysis of Clinical and Immunohistochemical Factors for Patients with Spinal Schwannoma.

BACKGROUND: Schwannoma comprises approximately 25% of all spinal tumors, but there is little information published in the literature regarding this subject. Our aim in this study was to discuss diagnostic and prognostic factors for spinal schwannoma. METHODS: A retrospective study was performed to analyze the clinical and immunohistochemical data of patients with spinal schwannoma surgically treated in our center between 2005 and 2013. RESULTS: A total of 524 patients with spinal schwannoma were included in the study. The mean follow-up period was 58.3 months. Forty-eight patients developed recurrence, and 26 died. Findings from the statistical analyses suggested duration of preoperative symptoms, Sridhar classification, tumor size, bone damage, Ki67 labeling index, and S100 expression were different between benign schwannoma and the malignant subtype. Recurrence was associated with resection mode, segments of involvement, pathology grade, CD57 expression, Ki67 labeling index, and S100 expression. The overall survival was closely related with recurrence, location in sacrum, pathology grade, Ki67 labeling index, and P53 expression. CONCLUSIONS: Compared with the benign subtype, malignant schwannoma has a shorter duration of preoperative symptoms, larger tumor size, greater Sridhar classification, and poorer prognosis. Total resection can significantly reduce recurrence but not guarantee a better survival, which is associated location and pathology grade. A Ki67 labeling index >5% was not only an index for malignant subtype but also a prognostic indicator for recurrence and poor survival. Moreover, S100-negative was a prognostic indicator for recurrence, whereas P53-positive was associated with a poor prognosis.

5-Fluoruracil blocked giant cell tumor progression by suppressing osteoclastogenesis through NF-kappaB signals and blocking angiogenesis.

Giant cell tumor of bone (GCTB) is a bone destroying tumor comprised of spindle-like stromal cells and monocytes of myeloid lineage that are differentiated into osteoclast-like multinucleated giant cells. Nuclear factor-Kappa B (NF-κB) has been identified to be essential for GCT progression. Herein, we found that 5-Fluorouracil (5-FU), a widely used chemotherapeutics, is a promising anticancer agent for GCT both targeting spindle-like stromal cells and osteoclast giant cells through NF-κB pathway. In this study, in vitro 5-FU not only directly blocked both stromal cell- and RANKL-induced osteoclastogenesis through NF-κB pathway, but also indirectly inhibited osteoclast formation and angiogenesis by suppressing the expression of osteoclast-activating factors including IL-1ß, MCP-1 and tumor angiogenesis factor VEGF in stromal cells. In vivo, we found that 5-FU blocked GCT progression through NF-κB pathway by utilizing our chick embryo chorioallantoic membrane (CAM) model. Taken together, our results suggest that 5-FU can inhibit GCT development by suppressing osteoclast formation through NF-κB pathway and blocking angiogenesis, and may serve as a novel agent in the treatment of GCT.