miR-181a promotes the proliferation and metastasis of osteosarcoma cells by targeting RASSF1A / 中南大学学报(医学版)

OBJECTIVE@#To investigate the role of miR-181a in promoting the proliferation and metastasis of osteosarcoma cells by targeting RASSF1A.
@*METHODS@#The level of miR-181a in 30 human osteosarcoma tissues and corresponding bone tissues was detected by real-time PCR, and the correlation between the level of miR-181a and clinicopathological characteristics of osteosarcoma was analyzed. Osteosarcoma cells MG-63 were transfected with chemically-synthesized miR-181a mimics and inhibitors, and the proliferation, migration and invasion of MG-63 cells were detected by MTT and Transwell assay. The specific binding ability of miR-181a to RASSF1A 3'-UTR was theoretically predicted and detected by the dual luciferase reporter gene assay.
@*RESULTS@#The level of miR-181a in osteosarcoma tissues was statistically higher than that in the corresponding bone tissues (P0.05). MTT and Transwell assays showed that the growth rate, migration and invasion ability of MG-63 cells with up-regulation of miR-181a was significantly increased compared with negative control (P<0.05), while the growth rate, migration and invasion ability of MG-63 with down-regulated miR-181a was significantly decreased compared with negative control (P<0.05). Luciferase reporter gene assay showed that miR-181a targeted the 3'-UTR of RASSF1A and regulated the expression of RASSF1A.
@*CONCLUSION@#MiR-181a promotes the proliferation and metastasis of osteosarcoma cells through specifically binding to RASSF1A 3'-UTR and subsequent down-regulation of RASSF1A.

Surgical correction of post-traumatic thoracolumbar kyphotic deformity with posterior transpedicular limited osteotomy technique / 中南大学学报(医学版)

OBJECTIVE@#To evaluate the clinical outcome of surgical management for post-traumatic thoracolumbar kyphotic deformity with single-stage posterior transpedicularlimited osteotomies.@*METHODS@#From March 2007 to May 2010, 17 patients with post-traumatic thoracolumbar kyphotic deformity treated with posterior limited transpedicular osteotomy were admitted. The preoperative Cobb angle was 41°-62°(52.5° ±6.4°). Sagittal balance was evaluated by the standing lateral films measuring the C7 plumb line distance (C7 PLD) from the posterior superior corner of S1. The C7 PLD was 18-58 (41.2 ±12.4) mm in the sagittal plane. The preoperative oswestry disability index (ODI) was 42-50 (45.7 ±2.7), and the average preoperative visual analogue scale (VAS) was 8-10 (8.8 ±0.7). The American Spinal Injury Association (ASIA) impairment scale was used to assess the neurological deficits, and grade C in 1 patient, grade D in 7 and grade E in 9 patients. The operation time, blood loss, complications, post-operative Cobb angle, ODI and VAS score at the follow-up were collected and analyzed.@*RESULTS@#The average duration of postoperative follow-up was 24-53 (34.5 ±7.1) months. The operation time was 180-400 (287.1 ±65.9) min, with an blood loss of 350-1 300 (838.2 ±276.4) mL. The postoperative kyphotic angle was 3°-12° (6.1° ±3.0°), and it was 7.5° ±2.6° at the final follow-up evaluation. The postoperative C7PLD was (3.6 ±3.9) mm and it was (3.4 ±2.3) mm at the final follow-up evaluation. Postoperatively, the ASIA impairment scale was grade D in 4 and grade E in 13 patients. At the final follow-up ODI and VAS were reduced to an average of 5.2 ±2.4 and 2.4 ±1.0, respectively. Cerebrospinal fluid leakage was found in 2 patients, deep wound infection in 1, and intercostal neuralgia in 2. All the complications were relieved after conservative medical therapy. One patient received additional surgery at postoperative 12 weeks due to breakage of posterior implants. Another screw pullout case was treated with reinsertion of larger screws at postoperative 4 months. Solid fusion was confirmed by plain film and CT scan in all patients within 1 year after the surgery.@*CONCLUSION@#Single-staged posterior transpedicular limited osteotomies is safe and effective to correct post-traumatic thoracolumbar kyphotic deformity.

Ezrin promotes invasion and migration of the MG63 osteosarcoma cell / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Evidence shows that ezrin plays an important role in the development of some human malignancies. But the mechanism by which ezrin may affect tumor cell invasion and metastasis remains unclear.</p><p><b>METHODS</b>In this study, the expression of ezrin was verified in osteosarcoma (OS) cells and tissues by comparison with normal bone cells and tissues using Western blotting. OS-MG63 were transfected with pcDNA3.1-ezrin or pGenesil-1/shRNA-ezrin and the stably transfected cells were selected with G418 to yield the ezrin cell line. The OS-MG63 tumor cells were delivered by tail vein to female BALB/c to develop pulmonary metastasis model in vivo. Ezrin was identified as a direct target of miR-183 via a luciferase reporter carrying the 3'-untranslated region of ezrin. Migration assays and invasion assays were done with the transwells. Signaling pathway was studied by Western blotting and/or inhibitor.</p><p><b>RESULTS</b>Ectopic overexpression of ezrin in OS cell line MG63 promoted tumor cell invasion and migration. Consistent with this, knockdown of ezrin inhibited tumor cell invasion and migration. Similar results were obtained in the experimental metastasis model in vivo. We identified ezrin as a direct target of miR-183. What is more, ectopic expression of ezrin could induce the expression of N-cadherin and enhance the activity of extracellular signal-regulated kinase (ERK) signaling.</p><p><b>CONCLUSION</b>Collectively, these results suggest that ezrin as a direct target of miR-183 promotes the aggressiveness of OS via increased N-cadherin and activating ERK signaling.</p>

The Mini-invasive Operation of Intramedullary Interlocking Nail and An Clinical Analysis / 中国医师杂志

Objective To analyse the application effect of intramedullary interlocking nail in the treatment of femoral and tibial fracture,to discuss the key of the mini-invasive operation.Methods 110 cases of femoral and tibial fracture treated by intramedullary nail from May,1997 to Oct,2001 were reviewed,78 cases were treated by mini-invasive open-reduction and internal fixation,32 cases were treated by intermal fixation without open-reduction.Results All cases were followed-up ,15 cases were delayed at the healing time,but all cases were healed in six months.Conclusion The application of intramedullary nail in the treatment of femoral and tibial frature by mini-invasion has advantages of less trauma,strong fixation,high healing rate,early motion can be obtanied ,but the key of the operation must be grasped.