Hongbo He

MALAT1 promotes osteosarcoma development by targeting TGFA via MIR376A

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a long non-coding RNA (lncRNA) that contributes to the initiation and development of many solid tumors, including osteosarcoma (OS). Here, we showed that MALAT1 was increased in human OS cell lines and tissues and promoted OS cell growth, while MALAT1 knockdown suppressed OS cell growth. We also detected downregulation of MIR376A, a suppressor of OS growth, and upregulation of TGFA, a promoter of OS growth, in OS tissues. TGFA expression was positively correlated with MALAT1 expression, and both were negatively correlated with MIR376A expression. There was a direct interaction between MIR376A and MALAT1 via a putative MIR376A binding site within the MALAT1 3′-untranslated region (3′-UTR). There was also a direct interaction between MIR376A and the TGFA 3′-UTR. Thus, MALAT1 may promote OS cell growth through inhibition of MIR376A, leading to increased expression of TGFA. Our results suggest a MALAT1/MIR376A/TGFA axis mediates OS cell proliferation and tumor progression.

MicroRNA-124 suppresses the migration and invasion of osteosarcoma cells via targeting ROR2-mediated non-canonical Wnt signaling

MicroRNAs (miRs) have been implicated in tumorigenesis through inhibition of the expression of their target genes at post-transcriptional levels.xa0miR-124 has been found to be downregulated in many malignant tumors including osteosarcomaxa0(OS). However, the detailed mechanism of miR-124 in the regulation of OS malignant phenotypes remains largely unclear. Here we aimed to explore the role of miR-124 in mediating OS cell migration and invasion, as well as the underlying regulatory mechanisms. Real-time RT-PCR data showed that miR-124 was frequently downregulated in OS cell lines compared to normal human osteoblast cells. We further conducted bioinformatic analysis and a luciferase reporter assay, and identified receptor tyrosine kinase-like orphan receptor 2xa0(ROR2) as a novel target of miR-124. Furthermore, we found that ROR2 was significantly upregulated in OS cell lines compared to normal human osteoblast cells, and miR-124 negatively mediated the protein level of ROR2 in U-2OS and Saos-2 cells. Moreover, transfection with miR-124 mimics significantly suppressed migration and invasion in the U-2OS and Saos-2 cells, while overexpression of ROR2 in the miR-124-transfected OS cells reversed the inhibitory effect of miR-124 upregulation on OS cell migration and invasion. In addition, we found that overexpression of miR-124 significantly suppressed the activity of non-canonical Wnt signaling, downstream of ROR2. Based on these findings, we suggest that miR-124 may inhibit OS metastasis, partly at least, via targeting ROR2 and thus suppressing the activity of ROR2-mediated non-canonical Wnt signaling.

Biomechanical comparison of lumbar total disc arthroplasty, discectomy, and fusion: effect on adjacent-level disc pressure and facet joint force

OBJECTnWith the increasing advocacy for total disc replacement (TDR) as a potential alternative to fusion in the management of lumbar degenerative disc disease, intradiscal pressures (IDPs) and facet joint stresses at the adjacent levels of spine have generated considerable interest. The purpose of this study was to compare adjacent-level IDPs and facet joint stresses among TDR, discectomy, and fusion.nnnMETHODSnTen fresh human cadaveric lumbar specimens (L2-S1) were subjected to an unconstrained load in axial torsion, lateral bending, flexion, and extension by using multidirectional flexibility test. Four surgical treatment modes-control (disc intact), discectomy, TDR, and fusion-were tested in sequential order at L4-5. During testing, the IDPs and facet forces following each treatment were calculated at the adjacent vertebral levels (L3-4 and L5-S1).nnnRESULTSnIntradiscal pressures and facet force pressures were similar between the intact condition and the TDR reconstruction at the L3-4 and L5-S1 levels under all loading conditions (p > 0.05). Compared with the intact and TDR groups, the discectomy and fusion groups had higher IDPs at the L3-4 and L5-S1 levels under all loading conditions (p < 0.05). No significant difference in the facet force pressure was noted among the intact, discectomy, and TDR groups at the L3-4 and L5-S1 levels under any loading conditions (p > 0.05). However, the facet force pressure produced for fusion was significantly higher than the mean values obtained for the intact, discectomy, and TDR groups at the L3-4 and L5-S1 levels under all loading conditions (p < 0.05).nnnCONCLUSIONSnLumbar TDR maintained adjacent-level IDPs and facet force pressures near the values for intact spines, whereas adjacent-level IDPs tended to increase after discectomy or fusion and facet forces tended to increase after fusion.

MicroRNA-205 acts as a tumor suppressor in osteosarcoma via targeting RUNX2

MicroRNAs (miRs) are a class of small non-coding RNAs, and negatively regulate gene expression through directly binding to the 3-untranslational region (UTR) of their target mRNA, which further leads to translational repression or mRNA degradation. Recently, various miRs have been implicated in the development and progression of osteosarcoma (OS). However, the underlying mechanism has not been fully uncovered. Our study aimed to reveal the exact role of miR-205 in OS, as well as the regulatory mechanism. In this study, we found that the expression of miR-205 was significantly reduced in a total of 34xa0OS tissue specimens compared to their matched adjacent normal tissues. Besides, it was also remarkably downregulated in OS cell lines (Saos-2, U2OS, SW1353, and MG63) compared to human osteoblast hFOB1.19 cells. Overexpression of miR-205 caused a significant decrease in the proliferation, migration and invasion of MG63 and U2OS cells. Runt-related transcription factorxa02 (RUNX2) was further identified as a target gene of miR-205. Moreover, the mRNA and protein expression of RUNX2 was reduced after miR-205 overexpression, but increased after knockdown of miR-205 in MG63 and U2OS cells. Furthermore, overexpression of RUNX2 effectively reversed the suppressive effect of miR-205 on the proliferation, migration, and invasion of MG63 and U2OS cells. The RUNX2 level was significantly increased in OS tissues compared to their matched adjacent normal tissues, as well as in OS cell lines compared to hFOB1.19 cells. In addition, the RUNX2 level was reversely correlated with the miR-205 level in OS tissues. Taken together, our data demonstrate that miR-205 acts as a tumor suppressor in OS via directly targeting RUNX2. Therefore, we suggest that the miR-205/RUNX2 axis may serve as a potential target for the treatment of OS.

MicroRNA-379 inhibits the proliferation, migration and invasion of human osteosarcoma cells by targetting EIF4G2

Osteosarcoma (OS) is an aggressive malignant mesenchymal neoplasm amongst adolescents. The aim of the present study was to explore the various modes of action that miR-379 has on the proliferation, migration, and invasion of human OS cells. miR-379 achieves this by targetting eukaryotic initiation factor 4GII (EIF4G2). Human OS cell lines U2OS and MG-63 were selected and assigned into blank, miR-379 mimics, miR-379 mimic negative control (NC), miR-379 inhibitors, miR-379 inhibitor NC, EIF4G2 shRNA, control shRNA, and miR-379 inhibitor + EIF4G2 shRNA group. The miR-379 expression and EIF4G2 mRNA expression were detected utilising quantitative real-time PCR (qRT-PCR) and the EIF4G2 protein expression using Western blotting. MTT assay, scratch test, Transwell assay, and flow cytometry were performed to determine the proliferation, migration, invasion, and cell cycle, respectively. In comparison with the miR-379 mimic NC group, the miR-379 mimics group had decreased EIF4G2 expression; the miR-379 inhibitors group indicated an increased EIF4G2 expression. Compared with the control shRNA group, the EIF4G2 expression was lower in the EIF4G2 shRNA group and the miR-379 expression was dropped in the miR-379 inhibitor + EIF4G2 shRNA group. The proliferation, migration, and invasion abilities of OS cells were reduced in the miR-379 mimics and EIF4G2 shRNA groups. The percentage of OS cells at the G0/G1 stage was increased, and the percentage at the S-stage was decreased in the miR-379 mimics and EIF4G2 shRNA groups. miR-379 may inhibit the proliferation, migration and invasion of OS cells through the down-regulation of EIF4G2.

Rupture of posterior cruciate ligament leads to radial displacement of the medial meniscus

BackgroundTo explore the association between the rupture of posterior cruciate ligament (PCL) and the radial displacement of medial meniscus under the conditions of different flexion and various axial loads.MethodsThe radial displacement value of medial meniscus was measured for the specimens of normal adult knee joints, including 12 intact PCLs, 6 ruptures of the anterolateral bundle (ALB), 6 ruptures of the postmedial bundle (PMB), and 12 complete ruptures. The measurement was conducted at 0°, 30°, 60°, and 90° of knee flexion angles under 200xa0N, 400xa0N, 600xa0N, 800xa0N and 1000xa0N of axial loads respectively.ResultsThe displacement values of medial meniscus of the ALB rupture group increased at 0° flexion under 800xa0N and 1000xa0N, and at 30°, 60° and 90° flexion under all loads in comparison with the PCL intact group. The displacement values of the PMB rupture group was higher at 0° and 90° flexion under all loads, and at 30° and 60° flexion under 800xa0N and 1000xa0N loads. The displacement of the PCL complete rupture group increased at all flexion angles under all loads.ConclusionsEither partial or complete rupture of the PCL can increase in the radial displacement of the medial meniscus, which may explain the degenerative changes that occuring in the medial meniscus due to PCL injury. Therefore, early reestablishment of the PCL is necessarily required in order to maintain stability of the knee joint after PCL injury.

Small interfering RNA-induced silencing of galectin-3 inhibits the malignant phenotypes of osteosarcoma in vitro

Osteosarcoma (OS) is the most common malignant tumor of bone. It has recently been demonstrated that galectin-3, a multifunctional β-galactoside-binding, is significantly upregulated in OS tissues, and is correlated with its progression and metastasis. However, the detailed role of galectin‑3 in the regulation of cellular biological processes in OS cells has remained to be elucidated. The present study reported that the mRNA and protein levels of galectin‑3 were significantly increased in OS tissues compared to those in their matched normal adjacent tissues. Furthermore, galectin‑3 was upregulated in three OS cell lines, Saos‑2, MG63 and U2OS, when compared with that in the human osteoblast cell line hFOB1.19. Knockdown of galectin‑3 by galectin‑3‑specific small interfering RNA markedly inhibited OS‑cell proliferation and induced cell apoptosis. Furthermore, silencing of galectin‑3 expression significantly inhibited OS cell migration and invasion, accompanied with a marked decrease in the protein expression of matrix metalloproteinase 2 and ‑9. Mechanistic investigation suggested that the mitogen‑activated protein kinase kinase/extracellular signal‑regulated protein kinase signaling pathway may be involved in the galectin‑3‑mediated OS cell invasion. In conclusion, the present study was the first to report that silencing of galectin‑3 inhibited the malignant phenotypes of osteosarcoma in vitro. Therefore, galectin-3 may serve as a potential therapeutic target for OS.

An atypical monomelic presentation of Mazabraud syndrome

Mazabraud syndrome is a rare condition characterized by a combination of fibrous dysplasia and intramuscular myxomas. In Mazabraud syndrome, the distribution of fibrous dysplasia is mostly polyomelic and frequently located in the femur, with myxomas adjacent to the fibrous dysplasia lesion of bone (mostly in the quadriceps muscle). However, when presented as atypical clinical features, patients of Mazabraud syndrome is either misdiagnosed or difficult to diagnose. We report an atypical monomelic case of Mazabraud syndrome in the right upper arm and discuss the difficulties in making an accurate diagnosis.

Is double-approach surgery and tenodesis without a gastrocnemius flap better for dealing with proximal fibular osteosarcoma?

BackgroundResection of proximal fibular osteosarcoma involving the posteromedial aspect of the fibula is challenging. Reconstruction using a gastrocnemius flap may result in significant lateral instability and abnormal knee movement. Furthermore, postoperative gait may be disturbed by foot drop resulting from scarification of the common peroneal nerve.MethodsBetween January 2011 and December 2013, five patients with proximal fibular osteosarcoma were treated via the double-approach procedure using en bloc resection without a gastrocnemius flap. Simultaneously, all patients received one-stage tenodesis of the anterior tibial and toe extensor tendons. Clinical outcomes, including local tumor recurrence, complications, and functional outcomes, were evaluated.ResultsThe mean follow-up duration was 47.2xa0months (range 42–52xa0months). No patients experienced local recurrence. The patients’ Enneking functional scores were excellent (80%) or good (20%) at the final follow-up.ConclusionsIn patients with proximal fibular osteosarcoma, the double-approach procedure allows easier and safer en bloc tumor resection with vessel and nerve protection. One-stage tenodesis without a gastrocnemius flap is associated with good functional outcomes.

Comprehensive analysis of gene mutation and expression profiles in fibrous dysplasia of bone via next-generation sequencing

// Hongbo He 1 , Qing Liu 1 , Can Zhang 1 , Zhan Liao 1 , Yupeng Liu 1 , Jun Wan 1 , Jian Tian 1 , Xiaopeng Tong 1 , Lichun Sun 1,2,3 and Wei Luo 1 1 Department of Orthopedics, Xiangya Hospital, Central South University, Changsha, Hunan, China 2 Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Institute of Pharmacy & Pharmacology, University of South China, Hengyang, China 3 Department of Medicine, School of Medicine, Tulane Health Sciences Center, New Orleans, LA, USA Correspondence to: Wei Luo, email: luowei0928@126.com Keywords : fibrous dysplasia; whole-exome sequencing (WES); transcriptome sequencing (RNAseq); single gene sequencing; SNV/InDel Received: May 07, 2017xa0xa0xa0xa0 Accepted: November 13, 2017xa0xa0xa0xa0 Epub: January 03, 2018 Abstract Fibrous dysplasia (FD) of bone is a rare and non-inheritable bone disease. Its precise molecular mechanisms remain unclear. We collected FD patient samples and applied the innovative technology of whole-exome sequencing (WES) and transcriptome sequencing (RNAseq) to analyze the gene mutations and expression profiles. By comparing gene mutations with both WES and RNAseq, and further filtering these mutations with gene expressional significance (average > 1TPM), we eventually identified 20 genes with non-synonymous single nucleotide variations (SNVs) occurring in the exonic regions of all FD samples. About 40 genes with SNVs were mutated in 50% of the FD samples, including GNAS (Guanine Nucleotide Binding Protein Alpha) and RTN4 (Reticulon 4). Particularly, in three of these patients (Patient 1, 3 and 4), GNAS were identified as having SNVs, with the nucleotide changed in exon 8 and the amino acid residue changed in position 201 (GNAS: NM_000516: exon8: c.G602A: p.R201H; or c.C601T: p.R201C). We only observed 2 genes, FAM21B (mutation type: deletion) and GAGE2A (mutation type: amplification), with copy number variations (CNVs) occurred in FD patients. When analyzing signaling pathways and biological functions, we predicted some key genes, such as GPCRs, G proteins, chemokine and ANK-associated genes, and their associated signaling networks might play critical roles in FD development. We further confirmed these observations via single gene sequencing and Q-PCR. Thus, the mutations of these genes may be connected with fibroblast and bone development disorders. These findings may provide a clue for our next investigation of FD pathogenesis and its molecular mechanisms.