Lowly expressed lncRNA PVT1 suppresses proliferation and advances apoptosis of glioma cells through up-regulating microRNA-128-1-5p and inhibiting PTBP1.

BACKGROUND: Glioma is a primary intracranial malignancy with poor prognosis, of which the pathogenesis remains to be elucidated. Therein, the aim of this study is to discuss the impacts of lncRNA plasmacytoma variant translocation 1 (PVT1)/microRNA-128-1-5p (miR-128-1-5p)/polypyrimidine tract-binding protein 1 (PTBP1) axis on the biological characteristics of glioma cells. METHODS: Glioma tissue samples (72 cases) and normal brain tissue samples (35 cases) were harvested. The expression of PVT1, miR-128-1-5p and PTBP1 in glioma tissues and cells was detected. Glioma cells were transfected with sh-PVT1, miR-128-1-5p mimics or miR-128-1-5p inhibitors to verify the impacts of PVT1 and miR-128-1-5p on DNA damage, cell colony formation, invasion, proliferation, migration and apoptosis of glioma U87 and U251 cells. The growth of transplanted tumor was tested by tumor xenograft in nude mice. The combination of PVT1 and miR-128-1-5p and the targeting relationship between miR-128-1-5p and PTBP1 were verified. RESULTS: PVT1 and PTBP1 expression was enhanced and miR-128-1-5p expression was degraded in glioma tissues and cells. Overexpressed miR-128-1-5p and lowly-expressed PVT1 promoted DNA damage, suppressed colony formation, invasion, proliferation and migration as well as boosted apoptosis of U251 and U87 cells. Up-regulating miR-128-1-5p and down-regulating PVT1 reduced transplanted tumor volume and weight of glioma in mice. Low expression miR-128-1-5p reversed the effect of low expression PVT1 on the biological characteristics of glioma cells. PVT1 specifically bound to miR-128-1-5p and PTBP1 was the target gene of miR-128-1-5p. CONCLUSION: This study suggests that down-regulated PVT1 or up-regulated miR-128-1-5p boosts apoptosis and attenuates proliferation of glioma cells by inhibiting PTBP1 expression. This study is essential for finding new therapeutic targets for glioma.

Treatment of single one-stage posterior atlantoaxial fixation in Chiari malformation / 中华外科杂志

Objective@#To explore the effects of surgical technique of single one-stage posterior C1-2 screw rod fixation of Chiari malformation (CM) associated with occipitalization and without atlantoaxial dislocation.@*Methods@#A total of 23 patients with CM treated between January 2014 and October 2015 in Department of Neurosurgery of Chinese People′s Liberation Army General Hospital were retrospective reviewed. All of them were diagnosis with CM associated with occipitalization and without atlantoaxial dislocation, including 8 males and 15 females, aging from 11 to 57 years (mean (35.5±10.52) years). Single one-stage posterior C1-2 screw rod fixation with bone grafting fusion was performed. Operation time and intraoperative blood loss were recorded. Japanese Orthopaedic Association (JOA) scores and Odom rating were used to evaluate the clinical effects at pre- and post-operative. Regression of the cerebellar tonsillar was measured by MRI. The results were analyzed by paired samples t test.@*Results@#Twenty-three patients were implanted screws successfully, the vertebral artery injury and cerebrospinal fluid leakage were not found. The mean operation time was (172.7±19.9) minutes, the intraoperative blood loss was (153.9±49.3) ml. Compared to preoperative, the JOA score increased (13.7±1.6 vs. 11.5±1.4) and the tonsillar herniation decreased ((0.8±0.6)cm vs. (1.9±0.6) cm) in the last follow-up, there were statistical difference (t=13.386, P<0.01; t=17.995, P<0.01). The results of the postoperative Odom grading were as follows: 6 cases were perfect (26.1%), 13 cases were good (56.5%), 4 cases were moderate (17.4%) and no case was poor.No signs of instrument loosen or screw broken was noticed. 100% bony fusion rate was achieved. The follow-up time was 6 to 23 months (mean (10.5±3.2) months). One case developed internal fixator related discomfort, the symptom was relieved by internal fixator removal surgery performed 4 months after the operation when osseous fusion had already been achieved. No new neurologic symptoms were observed in other 22 patients.@*Conclusions@#The results of the study substantiates the effectiveness of single one-stage posterior fixation strategy for CM, which is associated with occipitalization and without atlantoaxial dislocation. This technique could be an alternative choice for this type of CM.