Wenliang Zhai

MicroRNA-34a Inhibits Human Osteosarcoma Proliferation by Downregulating Ether a go-go 1 Expression

Aberrant expression of MicroRNAs (miRNAs) has been implicated in several types of cancer. As a direct target gene of p53, miR-34a has been suggested to mediate the tumor suppressor function of p53. Ether à go-go 1 (Eag1) channel is overexpressed in a variety of cancers and plays important roles in cancer progression. However, the link between miR-34a and Eag1 in cancer is unclear. In this study, we used human osteosarcoma as the model to demonstrate that miR-34a was significantly downregulated in osteosarcoma tissues and cell lines compared with normal brain tissues and osteoblastic cell line. Next we evaluated the role of miR-34a in the regulation of osteosarcoma cell proliferation by CCK-8 and colony formation assays. The results showed that overexpression of miR-34a inhibited the proliferation of MG-63 and Saos-2 cells. Furthermore, xenograft nude mice model showed that miR-34a inhibited osteosarcoma growth in vivo. Mechanistically, we found that overexpression of miR-34a led to decreased Eag1 expression in osteosarcoma cells while inhibition of miR-34a increased Eag1 expression. Taken together, our results suggest that miR-34a could inhibit osteosarcoma growth via the down regulation of Eag1 expression.

Conservative versus surgical management of Pipkin type I fractures associated with posterior dislocation of the hip: a randomised controlled trial

The aim of this study was to evaluate the long-term results of conservative and surgical fragment excision treatment in patients with Pipkin type 1 fractures of the femoral head associated with posterior dislocation of the hip by a randomised controlled trial. Sixteen patients were randomly divided into two groups: the conservative group was treated by closed reduction, and the surgical group was treated by closed reduction followed with fragment excision. Functional outcome was determined using the Thompson and Epstein score and the Merle d’Aubigne and Postel score. Outcome of the conservative group was worse than that of the surgical group (p = 0.032). The randomised controlled trial proves surgical fragment excision after closed reduction is an effective treatment for Pipkin type 1 fractures.

Short Hairpin RNA (shRNA) Ether à go-go 1 (Eag1) Inhibition of Human Osteosarcoma Angiogenesis via VEGF/PI3K/AKT Signaling

Ether à go-go 1 (Eag1) channel is overexpressed in a variety of cancers but the therapeutic potential of Eag1 in osteosarcoma remains elusive. In this study, we constructed an Ad5-Eag1-shRNA vector and evaluated its efficiency for Eag1 knockdown and its effects on osteosarcoma. Our results showed that Ad5-Eag1-shRNA had high interference efficiency of Eag1 expression and suppressed osteosarcoma growth both in vitro and in vivo. To explore the molecular mechanism underlying tumor growth inhibition induced by Eag1 silencing, the intratumoral microvessel density (MVD) was assessed by CD31 staining and the expression of vascular endothelial growth factor (VEGF) was detected by Western blot analysis. We found that Eag1 silencing led to decreased angiogenesis and VEGF expression in the xenograft model of osteosarcoma. Finally, we detected a time-dependent decrease in VEGF expression and considerably reduced phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT) activation in osteosarcoma cells treated by Eag1 shRNA. Taken together, our results suggest that Eag1 silencing inhibits tumor growth and angiogenesis in osteosarcoma via the down regulation of VEGF/PI3K/AKT signaling.

p38 MAPK regulates the expression of ether à go-go potassium channel in human osteosarcoma cells.

Abstract Background. The ether à go-go (Eag) channel has been shown to be overexpressed in a variety of cancers. However, the expression and function of Eag in osteosarcoma are poorly understood. In addition, the molecular mechanisms responsible for Eag overexpression in cancer cells remain unclear. Methods. The expression of Eag in human osteosarcoma cell line MG-63 was detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot analysis. The effect of Eag inhibition on MG-63 cell proliferation was assessed in vitro. The effect of short hairpin RNA (shRNA) mediated knockdown of Eag on osteosarcoma growth was evaluated in xenograft model in vivo. The activation of mitogen-activated protein kinase (MAPK) pathway and p53 in MG-63 cells was detected by Western blot analysis. Results. Eag was overexpressed in MG-63 cells. Imipramine or Eag shRNA significantly suppressed the proliferation of MG-63 cells in vitro and in vivo. MG-63 cell proliferation was specifically inhibited by p38 MAPK inhibitor SB203580 or small interference RNA (siRNA). The inhibition of p38 MAPK activation by SB203580 or siRNA reduced Eag protein level but increased p53 protein level. Moreover, the activation of p53 by nutlin-3 induced cell growth arrest in MG-63 cells and reduced Eag protein level, while the inactivation of p53 by pifithrin-alpha (PFT-α) promoted MG-63 cell growth and increased Eag protein expression. Conclusions. Eag channel functions as an oncogene to promote the proliferation of human osteosarocma cells. Furthermore, the high expression of Eag in osteosarcoma cells is regulated by p38 MAPK/p53 pathway.

Anterior versus posterior approach for four-level cervical spondylotic myelopathy.

The purpose of this study was to compare the results of 2 surgical strategies for 4-level cervical spondylotic myelopathy: a hybrid procedure using anterior cervical diskectomy and fusion (ACDF) combined with segmental corpectomy versus posterior laminectomy and fixation. Between 2002 and 2010, fifty-one patients with consecutive 4-level cervical spondylotic myelopathy were treated surgically, with 27 patients undergoing the hybrid procedure and 24 undergoing posterior laminectomy and fixation. Radiologic data were compared between the 2 groups, including cervical curvature and cervical range of motion (ROM) in the sagittal plane. Pre- and postoperative neurological status was evaluated using the Japanese Orthopaedic Association (JOA) scoring system and the Nurick grading system. Mean ROM at last follow-up was not significantly different between the 2 groups (P>.05). In the hybrid group, mean JOA score and Nurick grade improved from 9.6±1.4 and 2.74±0.45 respectively, preoperatively, to 13.9±1.3 and 0.86±0.38 respectively, postoperatively. In the fixation group, mean JOA score and Nurick grade improved from 9.4±1.2 and 2.81±0.42 respectively, preoperatively, to 13.1±1.5 and 1.32±0.36 respectively, postoperatively. The JOA scores and Nurick grades at last follow-up were significantly different between the 2 groups (P<.05). In patients with preoperative cervical kyphosis, preoperative JOA score and Nurick grade were not significantly different between the 2 groups (P>.05); however, JOA scores and Nurick grades at last follow-up showed better improvement in the hybrid group than in the fixation group (P<.01). In patients with preoperative cervical lordosis, the preoperative and last follow-up JOA score and Nurick grade were not significantly different between the 2 groups (P>.05).

Platelet-rich Plasma Reverses the Inhibition of Tenocytes and Osteoblasts in Tendon-Bone Healing

The purpose of this study was to investigate the effect of platelet-rich plasma on the proliferation of osteoblasts and tenocytes in tendon-bone healing. We cultured osteoblasts and tenocytes in an indirect coculture system with Transwell filters (Merck Millipore, Billerica, Massachusetts). The proliferation was examined using Cell Counting Kit-8 (Dojindo Chemistry Research Institute, Kumamoto, Japan).Four groups were studied: group 1, one cell type cultured without platelet-rich plasma; group 2, two cell types cultured together in an indirect coculture system without platelet-rich plasma; group 3, cells in the outer chamber and platelet-rich plasma in the inner chamber; and group 4, two different cell types in each of the 2 chambers with platelet-rich plasma in the inner chamber. The proliferation rates of groups 3 and 4 were the highest, followed by group 1 and then group 2, which was the lowest.Platelet-rich plasma abolishes the inhibition of osteoblasts or tenocytes in an indirect coculture system and improves the cell proliferation rate.

Proximal Femoral Locking Plate With Cannulated Screws for the Treatment of Femoral Neck Fractures

The purpose of this study was to evaluate the efficacy and safety of the proximal femoral locking plate with cannulated screws for the treatment of femoral neck fractures. A prospective study was performed in 41 patients with femoral neck fractures treated with a proximal femoral locking plate with cannulated screws between January 2005 and December 2008. Twenty-five men and 16 women had a mean age of 47 years (range, 21-65 years). The time from injury to surgery ranged from 2 hours to 7 days. Three patients had a Garden type I fracture, 9 a type II, 18 a type III and 11 a type IV. Operative time, intraoperative blood loss, fracture healing time, Harris Hip Score for hip function, and complications were recorded to evaluate treatment effects.Mean operative time was 63.6 minutes (range, 40-90 minutes), with mean intraoperative blood loss of 84.2 mL (range, 50-200 mL). Mean time to union was 15.5 weeks (range, 12-36 weeks). Two patients (Garden type III and type IV) did not achieve union, and 4 patients (1 Garden type III and 3 type IV) had avascular necrosis of the femoral head. In patients with nonunion, 1 (Garden type III) underwent intertrochanteric osteotomy, and the other underwent total hip replacement (THR). In patients with avascular necrosis, 2 required THR and the others (1 Garden type III) required no further surgery. Twenty-six (63%) patients had excellent results, 8 (20%) had good results, 3 (7%) had moderate results, and 4 (10%) had poor results. These findings suggest that the proximal femoral locking plate with cannulated screws for the treatment of femoral neck fractures is effective and results in fewer complications, especially for Garden type I, II, and III fractures.

Cervical ossification of the posterior longitudinal ligament: Anterior versus posterior approach

Background: The optimal approach to provide satisfactory decompression and minimize complications for ossification of the posterior longitudinal ligament (OPLL) involving multiple levels (3 levels or more) remains controversial. The purpose of this study was to compare the results of two surgical approaches for cervical OPLL involving multiple levels; anterior direct decompression and fixation, and posterior indirect decompression and fixation. We present a retrospective review of 56 cases followed at a single Institution. Materials and Methods: We compared patients of multiple levels cervical OPLL that were treated at a single institution either with anterior direct decompression and fixation or with posterior indirect decompression and fixation. The clinical records of the patients with a minimum duration of follow-up of 2 years were reviewed. The associated complications were recorded. Results: Fifty-six patients constitute the clinical material. 26 cases were treated by anterior corpectomy and fixation and 30 cases received posterior laminectomy and fixation. The two populations were similar. It was found that both anterior and posterior decompression and fixation can achieve satisfactory outcomes, and posterior surgery was accomplished in a shorter period of time with lesser blood loss. Although patients had comparable preoperative Japanese Orthopaedics Association (JOA) scores, those with a canal occupancy by OPLL more than 50% and managed anteriorly had better outcomes. However, for those with more severe stenosis, anterior approach was more difficult and associated with higher risks and complications. Despite its limitations in patients with high occupancy OPLLs, through the multiple level laminectomy, posterior fixation can achieve effective decompression, maintaining or restoring stability of the cervical spine, and thereby improving neural outcome and preventing the progression of OPLL. Conclusions: The posterior indirect decompression and fixation has now been adopted as the primary treatment for cervical OPLL involving multiple levels with the canal occupancy by OPLL <50% at our institution because this approach leads to significantly less implant failures. Those patients with the occupancy ≥50% managed with anterior approach surgeries had better outcomes, but approach was more difficult and associated with higher risk and complications.

Modified technique using allograft-prosthetic composite in the distal femur after bone tumor resection

BACKGROUND The purpose of this retrospective study was to analyze the results of treatment of bone tumor resection of the distal femur with the modified technique of allograft-prosthetic composite. METHODS Twelve patients with distal femoral bone tumors were treated with deep-frozen cortical allograft struts and allograft-prosthesis composites. There were five males and seven females with a median age of 29.5y. The minimum follow-up time was 12mo (median, 45.7mo; range, 12-81mo). Diagnoses included osteosarcoma in five patients, chondrosarcoma in three patients, giant cell tumors in three patients, and malignant fibrous histiocytoma in one patient. Five osteosarcoma patients were treated with adjuvant chemotherapy. RESULTS At the latest follow-up examination, 11 patients were alive with no evidence of disease, and the limb was preserved in nine patients. One patient died of pulmonary metastases with no evidence of local recurrence. Seven healed without complications. A surgical procedure was performed in four patients because of complications, which included a fracture (one patient), deep infection (one patient), instability (one patient), and local recurrence (one patient). CONCLUSION The modified technique of allograft-prosthetic composite is an effective treatment for bone tumor resection of the distal femur. This technique has many advantages, including augmentation of the bone stock, minimizing the risk of allograft fracture and nonunion, and decreasing the need for revision operations.

Ether à go-go 1 Silencing in Combination with TRAIL Overexpression Has Synergistic Antitumor Effects on Osteosarcoma

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been utilized for cancer therapy, but the resistance of cancer cells to TRAIL remains an obstacle. Ether à go-go 1 (Eag1) channel is overexpressed in a variety of cancers and implicated in tumor progression. However, the therapeutic potential of Eag1 in osteosarcoma remains elusive. In this study, we generated CRAd5.TRAIL/siEag1 adenoviral vector that permitted simultaneous knockdown of Eag1 and overexpression of TRAIL and investigated its antitumor effects on human osteosarcoma MG-63 cells. Our results showed that CRAd5.TRAIL/siEag1 induced growth arrest and apoptosis of MG-63 cells in a more efficient manner than CRAd5.TRAIL or CRAd5.siEag1, and had no effect on human osteoblastic hFOB 1.19 cells. Furthermore, treatment of an osteosarcoma xenograft model with CRAd5.TRAIL/siEag1 resulted in significant tumor regression and cancer cell apoptosis, compared with treatment with CRAd5.TRAIL or CRAd5.siEag1. Taken together, our results demonstrate that CRAd5.TRAIL/siEag1 may represent an effective strategy for osteosarcoma gene therapy due to the synergistic antitumor effects of Eag1 knockdown and TRAIL overexpression.