Glioma is the most common lethal tumor of the human brain. The median survival of patients with primary World Health Organization grade IV glioma is only 14.6 months. The World Health Organization classification of tumors of the central nervous system categorized gliomas into lower-grade gliomas and glioblastomas. Unlike primary glioblastoma that usually develop de novo in the elderly, secondary glioblastoma enriched with an isocitrate dehydrogenase mutant typically progresses from lower-grade glioma within 5-10 years from the time of diagnosis. Based on various evolutional trajectories brought on by clonal and subclonal alterations, the evolution patterns of glioma vary according to different theories. Some important features distinguish the normal brain from other tissues, e.g., the composition of the microenvironment around the tumor cells, the presence of the blood-brain barrier, and others. The underlying mechanism of glioma recurrence and evolution patterns of glioma are different from those of other types of cancer. Several studies correlated tumor recurrence with tumor heterogeneity and the immune microenvironment. However, the detailed reasons for the progression and recurrence of glioma remain controversial. In this review, we introduce the different mechanisms involved in glioma progression, including tumor heterogeneity, the tumor microenvironment and drug resistance, and their pre-clinical implements in clinical trials. This review aimed to provide new insights into further clinical strategies for the treatment of patients with recurrent and secondary glioma.
Aged ; Brain Neoplasms/genetics* ; Drug Resistance ; Glioblastoma ; Glioma/genetics* ; Humans ; Mutation ; Neoplasm Recurrence, Local/drug therapy* ; Tumor Microenvironment

Objectives:To establish a geometric model of the atlantoaxial dislocation and basilar invagination reduction,and examine its value for clinical application.Methods:A retrospective analysis of 35 patients with atlantoaxial dislocation and basilar invagination admitted to the Department of Neurosurgery,First Affiliated Hospital of Chongqing Medical University from May 2018 to May 2020 was conducted.There were 5 males and 30 females,aged (48±15) years(range: 19 to 69 years). The geometric model of the atlantoaxial reduction was established based on the mid-sagittal section of the cervical spine. The relevant data were calculated according to the geometric model before operation,and the fusion cage of the corresponding height was placed into C 1-2 facet joint of patient for quantitative reduction. The theoretical reset value, actual reset value, postoperative symptoms and complications were collected. The paired t-test was used to compare the difference between theoretical and actual reset value to verify the reliability of the geometric model. Results:The theoretical vertical reduction distance of all patients was (5.79±2.96) mm(range:1.52 to 10.96 mm),and the actual vertical reduction distance was (7.43±2.96)mm(range: 1.40 to 12.77 mm),and there was no statistical difference between them( t=-1.96, P=0.069).The theoretical reduction angle was (10.80±2.24)°(range: 7.09 to 14.86°), the actual reduction angle was (10.64±7.00)°(range: 3.50 to 20.50°),and there was no statistical difference between them ( t=0.09, P=0.933). At 6 months follow-up, 35 patients achieved satisfactory atlanto-axial joint fusion, and the symptoms were relieved. No internal fixation system displacement, fracture, wound infection and other complications occurred. Conclusion:This geometric model can estimate the vertical reduction distance and the reduction angle of the axial before operation,and provide a reference for the height of the fusion cage so as to avoid under or over-reduction.

Objectives:To establish a geometric model of the atlantoaxial dislocation and basilar invagination reduction,and examine its value for clinical application.Methods:A retrospective analysis of 35 patients with atlantoaxial dislocation and basilar invagination admitted to the Department of Neurosurgery,First Affiliated Hospital of Chongqing Medical University from May 2018 to May 2020 was conducted.There were 5 males and 30 females,aged (48±15) years(range: 19 to 69 years). The geometric model of the atlantoaxial reduction was established based on the mid-sagittal section of the cervical spine. The relevant data were calculated according to the geometric model before operation,and the fusion cage of the corresponding height was placed into C 1-2 facet joint of patient for quantitative reduction. The theoretical reset value, actual reset value, postoperative symptoms and complications were collected. The paired t-test was used to compare the difference between theoretical and actual reset value to verify the reliability of the geometric model. Results:The theoretical vertical reduction distance of all patients was (5.79±2.96) mm(range:1.52 to 10.96 mm),and the actual vertical reduction distance was (7.43±2.96)mm(range: 1.40 to 12.77 mm),and there was no statistical difference between them( t=-1.96, P=0.069).The theoretical reduction angle was (10.80±2.24)°(range: 7.09 to 14.86°), the actual reduction angle was (10.64±7.00)°(range: 3.50 to 20.50°),and there was no statistical difference between them ( t=0.09, P=0.933). At 6 months follow-up, 35 patients achieved satisfactory atlanto-axial joint fusion, and the symptoms were relieved. No internal fixation system displacement, fracture, wound infection and other complications occurred. Conclusion:This geometric model can estimate the vertical reduction distance and the reduction angle of the axial before operation,and provide a reference for the height of the fusion cage so as to avoid under or over-reduction.

Objective To explore the role of apoptosis signal regulating kinase 1(ASK1) in inflammatory mediated secondary injury after spinal cord injury(SCI) in rats.Methods The rat contusion SCI model was used.Forty-eight rats were randomly divided into the sham operation group(Sham),normal saline(Saline group) and inflammatory factors group (Cytokine group) respectively.The expressions of ASK1 and phosphorylated ASK1(pASK1) were detected by using Western blot.The Basso Beattie Bresnahan (BBB) scores and Grid Walking method were performed to assess the behavior changes of injured rat hindlimbs.Somatosensory evoked potential(SEP) and motor evoked potential(MEP) were used to examine the electrophysiological change.Results The expression levels of ASK1 mRNA and protein had no obvious change at 1 week after SCI;the pASK1 expression level in the Cytokine group was significantly up-regulated compared with the Saline group(P=0.002);the BBB scores at 3 or 4 weeks after SCI in the Cytokine group was significantly decreased compared with the Saline group (P =0.000,P =0.000);the hindlimbs missed step rate at 4 weeks following SCI in the Cytokine group was increased compared with the Saline group (P =0.032);the latent period of SEP and MEP in the Cytokine group was prolonged(P =0.043,P =0.045),while the wave peak value had no obvious changed (P =0.889,P=0.434).Conclusion Inflammatory cytokines may lead the hindlimbs movement dysfunction to be aggravated after SCI in rat,its mechanism may be related with the phosphorylation elevation of ASK1.

Objective To investigate the mechanism of IL-1β in promoting glial scar formation after spinal cord injury.Methods The experimental model of SCI was created by extradural compression of the spinal cord using an aneurysm clip.Rats were randomly divided into model group, sham operation group, IL-1β inhibitor IL-1RA group, IL-1β group and IL-1β+JAK2-STAT3 inhibitor AG490 group, according to different interventions, then were given normal saline, IL-1RA, IL-1β and IL-1β+AG490 every 10 μL respectively, sham group received only laminectomy.The motion function of the hindlimbs of rats was measured by Basso Beattie Bresnahan(BBB) scores and the expression of GFAP, vimentin and p-STAT3 were detected by Western blot technique, immunofluorescence assay and immunohistochemistry technique at corresponding time points(at the 8th, 12th hour, 1st, 3rd, 7th and 14th day after SCI).Results The expression trend of p-STAT3(at the 8th and 12th hour after SCI),GFAP and vimentin(at the 7th and 14th day after SCI)was: the expressions of p-STAT3, GFAP and vimentin in the model group were significantly higher compared with the sham group(P<0.01), the expression of p-STAT3,GFAP andvimentin in the IL-1RA group were significantly lower compared with the model group(P<0.05) whereas significantly higher compared with the sham group(P<0.05);the expressions of p-STAT3, GFAP and vimentin in the IL-1β+AG490 group were significantly lower compared with the model group(P<0.05)whereas significantly higher compared with the sham group(P<0.05), the expressions of p-STAT3, GFAP and vimentin in the IL-1β group were significantly higher compared with the model group(P<0.05).Conclusions IL-1β can improve glial scar formation via JAK2-STAT3 signal.Inhibition of IL-1β or JAK2-STAT3 can reduce glial scar formation and promote functional recovery of spinal nerve.

Objective The study was to investigate the value of deduction and application of anterior compression index in evaluation of atlantoaxial dislocation and restoration. Method Twenty-eight cases of the control group and 28 cases of atlantoaxial dislocation treated with posterior restoration and screw-rod internal fixation technique before and af?ter surgery were recruited in this study and their data was retrospectively analyzed. All of the people underwent sagittal computerized tomography scan films. The anterior compression index was measured in all cases. Results The mean value of anterior compression index of the control group was 87.86±24.98. The mean value of anterior compression index of the preoperative patients was 230.44 ± 97.60 and the mean value of the postoperative patients was 106.27 ± 73.53. There was significant difference in those two parameters between the preoperative patients and the controls(t=-7.50,P<0.0001). There was no significant difference between the postoperative patients and the control group (t=-1.26, P=0.2171). Anteri?or compression index were significantly lower after surgical operation (t=10.35, compared with before, P<0.0001). Con?clusion Anterior compression index can be an excellent measurement tool for the assessment of relationship of atlas and axis in atlantoaxial dislocation patients before and after posterior restoration operation.

Objective To evaluate the value of electrospun polymethyl methacrylate (PMMA) nanofibers with different topological structures as scaffolds for growth of Schwann cells (SCs).Methods Electrospun PMMA nanofibers with random or aligned topological structures were fabricated and measured with biocompatibility.Lentivirus-transfected green fluorescent protein was used as the reporting gene to monitor form and growth manner of SCs on different substrates and dependency of cell body and process with fiber structure,with PMMA thin films served as the control.Results Electrospun PMMA nanofibers revealed good biocompatibility and could exert contact guidance to the growth of SCs.Topological structures of the electrospun nanofibers influenced cell morphology.SCs were aligned with the orientation of substrate fibers and form longer cell process when growing on aligned nanofibers (P ＜0.01).Primary SCs preferred to follow the cue of aligned nanofibers compared to random fibers.Conclusion Aligned electrospun PMMA nanofibers have the potentiality as transplantable scaffolds for loading SCs after neural injury.

Objective To investigate the effect of suppressing apoptosis signal regulating kinase 1 (ASK1) on glial fibrillary acidic protein (GFAP) and vimentin expressions at the injury site and on hindlimb mobility in rats after spinal cord injury (SCI). Methods The rat models of SCI were established by extradural compression of the spinal cord using an aneurysm clip. The injured rats were treated with normal saline (model group), ASK1 specific inhibitor thioredoxin (Trx group), or ASK1 monoclonal antibody (Anti-ASK1 group), and the rats receiving a sham operation underwent laminectomy without SCI. The expression of GFAP and vimentin were detected by Western blotting and immunofluorescence assay at 1, 7, 14 and 28 days after SCI. The motion function of the hindlimbs of the injured rats was assessed with Basso Beattie Bresnahan (BBB) scores, and somatosensory- evoked potentials (SEP) and motor- evoked potentials (MEP) were determined to examine the electrophysiological changes. Results At 1 day after SCI, the expressions of GFAP and vimentin showed no significant differences among the groups;at 7, 14 and 28 days after SCI, GFAP and vimentin expressions significantly increased in Trx and Anti-ASK1 groups compared with those in the model group (P<0.01). The BBB scores showed no significant differences among the groups at 1, 7 and 14 days after SCI, while at 28 days, the BBB scores in Trx and Anti-ASK1 groups were significantly higher than those in the model group (P<0.01). At 28 days after SCI, the latent period of SEP and MEP decreased and the amplitude increased significantly in Trx and Anti-ASK1 groups compared with that in the model group (P<0.01). Conclusion Blocking ASK1 can inhibit the expression of GFAP and vimentin in glial scars and improve the outcomes of hindlimb mobility in rats after SCI.

Objective To investigate the effect of suppressing apoptosis signal regulating kinase 1 (ASK1) on glial fibrillary acidic protein (GFAP) and vimentin expressions at the injury site and on hindlimb mobility in rats after spinal cord injury (SCI). Methods The rat models of SCI were established by extradural compression of the spinal cord using an aneurysm clip. The injured rats were treated with normal saline (model group), ASK1 specific inhibitor thioredoxin (Trx group), or ASK1 monoclonal antibody (Anti-ASK1 group), and the rats receiving a sham operation underwent laminectomy without SCI. The expression of GFAP and vimentin were detected by Western blotting and immunofluorescence assay at 1, 7, 14 and 28 days after SCI. The motion function of the hindlimbs of the injured rats was assessed with Basso Beattie Bresnahan (BBB) scores, and somatosensory- evoked potentials (SEP) and motor- evoked potentials (MEP) were determined to examine the electrophysiological changes. Results At 1 day after SCI, the expressions of GFAP and vimentin showed no significant differences among the groups;at 7, 14 and 28 days after SCI, GFAP and vimentin expressions significantly increased in Trx and Anti-ASK1 groups compared with those in the model group (P<0.01). The BBB scores showed no significant differences among the groups at 1, 7 and 14 days after SCI, while at 28 days, the BBB scores in Trx and Anti-ASK1 groups were significantly higher than those in the model group (P<0.01). At 28 days after SCI, the latent period of SEP and MEP decreased and the amplitude increased significantly in Trx and Anti-ASK1 groups compared with that in the model group (P<0.01). Conclusion Blocking ASK1 can inhibit the expression of GFAP and vimentin in glial scars and improve the outcomes of hindlimb mobility in rats after SCI.

OBJECTIVETo evaluate the impact of the topographic features of electrospun polymethylmethacrylate (PMMA) nanofibers on growth pattern of primary rat astrocytes.

METHODSRat astrocytes were cultured on fabricated random and aligned electrospun nanofibers. Using PMMA film as the control, the cells were transfected with a lentivirus harboring GFP gene to reveal the cell growth pattern on different substrates.

RESULTSoth random and aligned electrospun PMMA nanofibers could support the growth of rat astrocytes, but the topographic features of the fibers significantly affected their growth pattern. On aligned nanofibers, astrocytes extended long cell processes along the direction of the substrate fibers, and on random fibers the astrocytes formed shorter processes. On merged images of GFP expressions and substrate fibers, the cell processes of the astrocytes were shown to adhere to and elongate along the fibers both on random and aligned nanofibers.

CONCLUSIONThe topographic features of PMMA nanofibers can significantly influence the growth pattern of primary rat astrocytes. Aligned electrospun nanofibers has the potential to serve as scaffold material for reducing glia scar formation after spinal cord injury.