Detection of mutation profiles and tumor mutation burden of cerebrospinal fluid circulating DNA by a cancer genomic panel sequencing in glioma patients.

BACKGROUND AND AIMS: Circulating tumor DNA (ctDNA) has been recognized as a reliable source to reflect the molecular and genetic landscape of corresponding tumors in recent years. In this study, we tested the application of a cancer genomic panel sequencing on the cerebrospinal fluid (CSF)-derived ctDNA for the less invasive detection and diagnosis of glioma. MATERIALS AND METHODS: CtDNA was extracted from 26 CSF samples and subject to a cancer genomic panel sequencing of 520 genes to analyze the mutation profiles and tumor mutation burden (TMB), which were compared with their corresponding tumor DNA samples. Associations between mutations or TMB and clinical characteristics were also evaluated. RESULTS: A high detection rate of ctDNA (24/26, 92.3%) was observed in CSF. CtDNA mutations had high concordance rates with tumor DNA, especially in non-copy number variations and in glioblastoma. CSF ctDNA TMB also exhibited a strong correlation with tumor DNA TMB (R2 = 0.879, P < 0.001), particularly in glioblastoma (R2 = 0.992, P < 0.001). Age was significantly associated with CSF ctDNA TMB in glioma patients. CONCLUSION: We established a less invasive but effective molecular diagnostic approach using a cancer genomic panel sequencing system targeting CSF ctDNA for glioma, especially in glioblastoma.

Modified Nasoseptal Rescue Flap Technique for Pituitary Adenoma Resection via Endoscopic Endonasal Approach.

ABSTRACT: Nasoseptal rescue flap (NSRF), which preserves the pedicle of the flap and is harvested as a nasoseptal flap (NSF) when intraoperative leakage of cerebrospinal fluid (CSF) occurs, is an alternative strategy for skull base reconstruction in patients with pituitary adenoma resection via an endoscopic endonasal approach. However, in practice, the original NSRF technique cannot meet the needs during operation. Therefore, the authors aimed to describe a modified NSRF technique for the resection of pituitary adenoma via endoscopic endonasal approach and to examine its utility and outcomes. The authors retrospectively analyzed the medical records of 87 consecutive patients with pituitary adenoma who underwent endoscopic endonasal surgery performed using NSRF technique from September 2019 to August 2020. Data on intraoperative CSF leakage, NSF conversion rate, and reconstruction-related complications were analyzed. The average age of patients was 50.1 years (men, 50.5%). Twenty-five cases of intraoperative CSF leakage were observed: 23 cases of low-flow CSF leakage and two cases of high-flow CSF leakage. NSRF was converted to NSF in 11 cases. Two patients experienced postoperative CSF leakage after reconstruction without NSF and required unplanned reoperation to rebuild the skull base with NSF. In conclusion, this modified NSRF utilized a minimally invasive way to provide sufficient surgical corridor without the need for pedicle retraction, and it can be effectively converted to an NSF for skull base reconstruction in patients with pituitary adenoma.

Analysis of the Expression of Angioarchitecture-related Factors in Patients with Cerebral Arteriovenous Malformation.

BACKGROUND: Cerebral arteriovenous malformation (cAVM) is a type of vascular malformation associated with vascular remodeling, hemodynamic imbalance, and inflammation. We detected four angioarchitecture-related cytokines to make a better understanding of the potential aberrant signaling in the pathogenesis of cAVM and found useful proteins in predicting the risk of cerebral hemorrhage. METHODS: Immunohistochemical analysis was conducted on specimens from twenty patients with cAVM diagnosed via magnetic resonance imaging and digital subtraction angiography and twenty primary epilepsy controls using antibodies against vascular endothelial growth factor receptor-2 (VEGFR-2), matrix metalloproteinase-9 (MMP-9), vascular cell adhesion molecule (VCAM-1), and endothelial nitric oxide synthase (eNOS). Western blotting and real-time fluorescent quantitative polymerase chain reaction (PCR) were performed to determine protein and mRNA expression levels. Student's t-test was used for statistical analysis. RESULTS: VEGFR-2, MMP-9, VCAM-1, and eNOS expression levels increased in patients with cAVM compared with those in normal cerebral vascular tissue, as determined by immunohistochemical analysis. In addition, Western blotting and real-time PCR showed that the protein and mRNA expression levels of VEGFR-2, MMP-9, VCAM-1, and eNOS were higher in the cAVM group than in the control group, all the differences mentioned were statistically significant (P < 0.05). CONCLUSIONS: VEGFR-2, MMP-9, VCAM-1, and eNOS are upregulated in patients with cAVM and might play important roles in angiogenesis, vascular remodeling, and migration in patients with cAVM. MMP-9, VEGFR-2, VCAM-1, and eNOS might be potential excellent group proteins in predicting the risk of cerebral hemorrhage at arteriovenous malformation.

Characterizing nanoscale changes in the activity of VEGFR-2 on glioma microvascular endothelial cell membranes using atomic force microscopy.

The aim of the current study was to demonstrate the distribution of VEGFR-2 on glioma microvascular endothelial cells on a nanoscale and investigate changes in VEGFR-2 activity following treatment with the VEGFR-2 inhibitor and agonist sorafenib and bradykinin, respectively. Three groups were evaluated in this study: Control glioma microvascular endothelial cells, sorafenib-treated glioma microvascular endothelial cells and bradykinin-treated glioma microvascular endothelial cells. Changes in the activity of VEGFR-2 on the glioma microvascular endothelial cell membranes following treatment with sorafenib and bradykinin were characterized by atomic force microscopy (AFM). Colloidal gold-labeled immune complexes and AFM were used to visualize the distribution of VEGFR-2 on the cell membranes. In the control group, VEGFR-2, which was observed as numerous globular structures, was evenly distributed on the cell surface membranes. The majority of the receptors were active. In the sorafenib group, only a few globular structures were observed on the cell membranes, with a density significantly lower than that in the control group (P<0.01). Furthermore, compared with the control group, fewer of the receptors were active. In the bradykinin group, numerous globular structures were densely distributed on the cell membranes, with a density significantly higher than that in the control group (P<0.01). The distribution and activity of VEGFR-2 on glioma microvascular endothelial cell membranes treated with sorafenib and bradykinin suggested that the activity of VEGFR-2 could be regulated by its inhibitor or agonist.

Clinical Features of Brain Metastases in Small Cell Lung Cancer: an Implication for Hippocampal Sparing Whole Brain Radiation Therapy.

PURPOSE: To assess the clinical features and distribution of brain metastases (BMs) of small cell lung cancer (SCLC) in the hippocampal and perihippocampal region, with the purpose of exploring the viability of hippocampal-sparing whole-brain radiation therapy (HS-WBRT) on reducing neurocognitive deficits. METHODS: This was a retrospective analysis of the clinical characteristics and patterns of BMs in patients with SCLC. Associations between the clinical characteristics and hippocampal metastases (HMs)/perihippocampal metastases (PHMs) were evaluated in univariate and multivariate regression analyses. RESULTS: A total of 1594 brain metastatic lesions were identified in 180 patients. Thirty-two (17.8%) patients were diagnosed with BMs at the time of primary SCLC diagnosis. The median interval between diagnosis of primary SCLC and BMs was 9.3 months. There were 9 (5.0%) and 22 (12.2%) patients with HMs and PHMs (patients with BMs located in or within 5 mm around the hippocampus), respectively. In the univariate and multivariate analysis, the number of BMs was the risk factor for HMs and PHMs. Patients with BMs≥5 had significantly higher risk of HMs (odds ratio [OR] 7.892, 95% confidence interval [CI] 1.469-42.404, P=.016), and patients with BMs≥7 had significantly higher risk of PHMs (OR 5.162, 95% CI 2.017-13.213, P=.001). Patients with extracranial metastases are also associated with HMs. CONCLUSIONS: Our results indicate that patients with nonoligometastatic disease are significantly associated with HMs and PHMs. The incidence of PHMs may be acceptably low enough to perform HS-WBRT for SCLC. Our findings provide valuable clinical data to assess the benefit of HS-WBRT in SCLC patients with BMs.

Combination of lentivirus-mediated silencing of PPM1D and temozolomide chemotherapy eradicates malignant glioma through cell apoptosis and cell cycle arrest.

Temozolomide (TMZ) is approved for use as first-line treatment for glioblastoma multiforme (GBM). However, GBM shows chemoresistance shortly after the initiation of treatment. In order to detect whether silencing of human protein phosphatase 1D magnesium dependent (PPM1D) gene could increase the effects of TMZ in glioma cells, glioma cells U87-MG were infected with lentiviral shRNA vector targeting PPM1D silencing. After PPM1D silencing was established, cells were treated with TMZ. The multiple functions of human glioma cells after PPM1D silencing and TMZ chemotherapy were detected by flow cytometry and MTT assay. Significantly differentially expressed genes were distinguished by microarray-based gene expression profiling and analyzed by gene pathway enrichment analysis and ontology assessment. Western blotting was used to establish the protein expression of the core genes. PPM1D gene silencing improves TMZ induced cell proliferation and induces cell apoptosis and cell cycle arrest. When PPM1D gene silencing combined with TMZ was performed in glioma cells, 367 genes were upregulated and 444 genes were downregulated compared with negative control. The most significant differential expression pathway was pathway in cancer and IGFR1R, PIK3R1, MAPK8 and EP300 are core genes in the network. Western blotting showed that MAPK8 and PIK3R1 protein expression levels were upregulated and RB1 protein expression was decreased. It was consistent with that detected in gene expression profiling. In conclusion, PPM1D gene silencing combined with TMZ eradicates glioma cells through cell apoptosis and cell cycle arrest. PIK3R1/AKT pathway plays a role in the multiple functions of glioma cells after PPM1D silencing and TMZ chemotherapy.

Brain abscess after endosaccular embolisation of a cerebral aneurysm.

Endovascular embolization has become an important treatment option for cerebral aneurysms, along with surgical clipping. But few literatures mentioned infectious complications after coiling of aneurysms. We present a patient with a brain abscess that developed after endosaccular embolization of a left middle cerebral artery aneurysm. The brain abscess was located adjacent to the aneurysm and discovered more than 2 months after embolization. We discuss the clinical implications of this rare complication and review the literature for infections related to the coils used for embolization of aneurysms.

Macrophage migration inhibitory factor reduces apoptosis in cerebral arteriovenous malformations.

PURPOSE: To investigate the expression of macrophage migration inhibitory factor (MIF) in human brain arteriovenous malformations (AVM). MATERIALS AND METHODS: Twelve AVM specimens were obtained from patients who did not received preoperative embolization. MIF levels were measured by Western blot and matrix metalloproteinase 9 (MMP9) levels were measured by reverse transcription PCR. The expression of MIF in brain AVMs was also evaluated by immunohistochemistry and was correlated with apoptosis and the expression of cleaved caspase-3 and MMP9. RESULTS: The expression of MIF, MMP9, and cleaved caspase-3 was elevated in brain AVM vessels. High levels of MIF were primarily found in the endothelium and adventitia, whereas apoptotic cells were concentrated in the smooth muscle layer. CONCLUSIONS: Abnormal apoptosis may be involved in the pathogenesis of brain AVM. In addition, increased MIF expression could play an important role regulating the homeostasis of AVM vessels.

[Neuroendoscopic treatment for 372 cases of intracranial lesions].

OBJECTIVE: To explore the application of neuroendoscopic treatment for intracranial lesions. METHODS: The clinic data of 372 patients with intracranial lesions, who underwent neuroendoscopic treatment at our department from May 1998 to May 2010, were reviewed retrospectively. Representative endoscopic treatments included endoscopic third ventriculostomy (ETV) (n = 198), ETV & endoscopic biopsy (n = 69), neuroendoscopic ostomy for septum pellucidum fenestration (n = 55) (for septum pellucidum cysts, n = 37) and endoscopic cystoventriculostomy for ventricular cysts (n = 50). Their surgical indications and clinical outcomes were summarized for analysis. RESULTS: ETV was performed successfully in 369 cases. Among them, 2 failed cases underwent other operations and endoscopic biopsy failed in 1 case. Within a short post-operative period, the symptoms were resolved in 347 cases (93.3%), showed no improvement in 23 cases (6.2%) and 2 died (0.5%). At Month 6 post-operation, a failure of ETV was detected in 22 cases (9.5%), a failure of neuroendoscopic ostomy for septum pellucidum cysts in 23 (69.7%) and for ventricular cysts in 12 cases (26.7%). CONCLUSION: ETV is effective in the treatment of obstructive hydrocephalus, but its indication should be strictly controlled for children. Effective rate of neuroendoscopic treatment for intracranial septum pellucidum cysts remains unsatisfactory so that its operative indication should be strictly controlled.

A study of the distribution and density of the VEGFR-2 receptor on glioma microvascular endothelial cell membranes.

The purpose of the study was to examine the nanoscale distribution and density of the VEGFR-2 membrane receptor on the endothelial cell surface of glioma microvasculature. Immunofluorescence and atomic force microscopy combined with immunogold labeling techniques were used to characterize and determine the position of the glioma microvasculature endothelial cell surface receptor VEGFR-2. We aimed to indirectly detect the distribution of VEGFR-2 on the cell membrane at the nanoscale level and to analyze VEGFR-2 quantitatively. Immunofluorescence imaging showed a large amount of VEGFR-2 scattered across the endothelial cell surface; atomic force microscopy imaging also showed two globular structures of different sizes scattered across the endothelial cell surface. The difference between the average diameter of the small globular structure outside the cell surface (43.67 ± 5.02 nm) and that of IgG (44.61 ± 3.19 nm) was not statistically significant (P > 0.05). The three-dimensional morphologies of the small globular structure outside the cell surface and IgG were similar. The difference between the average diameter of the large globular structure outside the cell surface (74.19 ± 9.10 nm) and that of IgG-SpA-CG (74.54 ± 15.93 nm) was also not statistically significant (P > 0.05). The three-dimensional morphologies of this large globular structure outside the cell surface and IgG-SpA-CG were similar. The total density of these two globular structures within the unit area was 92 ± 19 particles µm(2). No globular structures were seen on the cell surface in the control group. The large globular structure on the surface of glioma microvascular endothelial cells was categorized as a VEGFR-2-IgG-SpA-CG immune complex, whereas the small globular structure was categorized as a VEGFR-2-IgG immune complex. The positions of the globular structures were the same as the positions of the VEGFR-2 molecules. A large amount of VEGFR-2 was scattered across glioma microvascular endothelial cell surfaces; the receptor density was about 92 per square micron.

[Application of neuroendoscopy in brain surgery].

OBJECTIVE: To investigate the effect of neuroendoscope on surgery. METHODS: 315 patients were treated with neuroendoscope. Endoscopic neurosurgery (EN) was used in 219 patients, endoscope-assisted microneurosurgery (EAM) in 72, and endoscope-controlled microneurosurgery (ECM) in 24. RESULTS: 201 (91.8%) of the 219 patients underwent EN effectively. In 72 patients who underwent EAM there was less retraction during tumor removal and visual control was improved. 21 (87.5%) of the 24 patients underwent ECM effectively. No severe complications were observed. CONCLUSION: Neuroendoscopy can reduce tissue trauma, improve visualization during tumor removal, and reduce complications.