Targeting CD146 using folic acid-conjugated nanoparticles and suppression of tumor growth in a mouse glioma model.

OBJECTIVE: Glioma stem cells (GSCs) are responsible for tumor initiation, therapeutic resistance, and recurrence. CD146 is mainly expressed in dividing GSCs and regulates cell cycle progression. However, the evaluation of the efficacy of targeted therapy against CD146 in vivo remains to be investigated. In this study, the authors aimed to develop gene therapy targeting GSCs using chitosan oligosaccharide lactate (COL) nanoparticles (NPs) conjugated with folic acid-polyethylene glycol (FA-PEG-COL NPs) for in vitro and in vivo delivery of CD146 small-interfering RNA (siCD146) and to determine the effect of CD146 knockdown on tumor growth. METHODS: To examine the uptake of NPs by tumor cells, immunofluorescence staining, flow cytometry, and in vivo imaging were performed. The knockdown effect of siCD146 was measured by western blot and water-soluble tetrazolium salt-8 assay in mouse glioma cells. The efficacy of siRNA therapy-targeted GSCs was evaluated by monitoring tumor growth through in vivo imaging and histological analysis. RESULTS: In vivo accumulation of the FA-PEG-COL NPs in subcutaneous and intracranial gliomas following NP administration via a mouse tail vein was observed. Additionally, in vitro delivery of siCD146 ionically cross-linked NPs, reduced CD146 levels, and suppressed growth in the glioma tumor sphere. Evaluation of the in vivo therapeutic effects of siCD146-cross-linked NPs in a mouse glioma model revealed significant suppression of intracranial tumor growth, with complete removal of the tumor observed in some mice on histological examination. Furthermore, delivery of siCD146 significantly reduced the Ki-67 index in residual tumor tissues relative to that in control mice. CONCLUSIONS: CD146 is a potential therapeutic target, and folic acid-conjugated NPs delivering siRNA may facilitate gene therapy in malignant gliomas.

[Preliminary Experience of a Biplane Flat Panel and Tailor-made Operating Table-equipped Hybrid Operating Room].

A hybrid operating room(Hybrid OR), where operative equipment and flat panel angiography are both available, is becoming common for complex cerebrovascular surgery. However, the current Hybrid OR remains suboptimal as it is not cost-effective and contains uncomfortable operating beds, and a single-plane flat panel. Therefore, we introduced a novel Hybrid OR system, which has a biplane flat panel detector and three mutually exchangeable tailor-made operating beds. In this article, we report our preliminary experience of this novel Hybrid OR, focusing on improved cost-effectiveness by the availability of diagnostic angiography and standard endovascular surgery, optimal selection of three different types of operating beds, and procedural workflow in individual hybrid cerebrovascular surgery.

[Recurrent High-grade Astroblastoma Treated with Stereotactic Radiotherapy:A Case Report].

INTRODUCTION: Astroblastoma is a rare, supratentorial glial tumor, occurring predominantly in children and young adults. However, treatment strategies have not yet been established for this rare disease. CASE PRESENTATION: A 6-year-old boy presented with headache and nausea. CT and MRI revealed a left frontal mass lesion with slight edema and macrocalcifications. Gross tumor resection was performed. Histological examination found neoplastic cells with astroblastic characteristics, and a striking perivascular array of pseudorosettes. The final diagnosis was high-grade astroblastoma. MRI 13 months after surgery suggested local recurrence, and an enlargement was found 3 months later. Stereotactic radiotherapy(SRT)was performed. MRI after SRT showed enhanced cyst formation around the tumor bed, suggesting tumor recurrence. However, 11C-methionine positron emission tomography(PET)revealed radiation necrosis. The last follow-up MRI 15 months after SRT showed no further recurrence. CONCLUSION: Astroblastoma is rare, therefore, no optimal management is known. SRT may be effective to treat recurrent astroblastomas. 11C-methionine PET/CT was useful to differentiate metastatic disease from radiation necrosis.

CD146 is highly expressed in glioma stem cells and acts as a cell cycle regulator.

INTRODUCTION: CD146 is highly expressed in various malignant tumors and contributes to their malignancy phenotype, which involves metastatic and tumorigenic activity. However, studies on the expression and function of CD146 in brain tumors are limited. METHODS: We over-expressed or knocked-down CD146 in both conventionally cultured glioma cells and tumor spheres (TS). The distribution of glioma cells and their stem cells in different cell cycle phases was analyzed by flow cytometry using the stem cell marker CD133 and the glial precursor marker A2B5. CD146 expression was immunohistochemically examined in glioma tissues. RESULTS: The majority of glioma stem cells (GSCs) expressing CD133 were also CD146-positive. CD146 knockdown in GSCs significantly compromised cell growth. Cell cycle analysis revealed that most of the CD146 and CD133 double-positive cells were in the G2/M phase. Ectopic expression of CD146 in parental glioma cells resulted in cell cycle arrest of most differentiated cells in G0/G1 phase. In contrast, ectopic expression of CD146 in GSCs resulted in an increase in the number of CD133-positive cells in the G2/M phase. Furthermore, CD146 knockdown reduced the number of CD133-positive cells in the G2/M phase, which was consistent with effects of cell growth inhibition. Immunohistochemical analysis revealed that CD146 expression was significantly upregulated in World Health Organization (WHO) Grade III and IV glioma and positively correlated with CD133 expression. CONCLUSIONS: CD146 is mainly expressed in dividing GSCs and may be a potential target for eradicating glioma stem cells.

Evaluation of two- and three-dimensional visualization for endoscopic endonasal surgery using a novel stereoendoscopic system in a novice: a comparison on a dry laboratory model.

BACKGROUND: Three-dimensional (3-D) stereoscopic vision is theoretically superior to two-dimensional (2-D) vision in endoscopic endonasal surgery. However, only few reports have quantitatively compared endoscopic performance under the two visual conditions. We introduced a newly designed stereoendoscopic system with a "dual-lens and single camera" for endoscopic endonasal surgery and objectively compared the performances under 3-D and high-definition 2-D visualizations on a dry laboratory model. METHODS: Thirty subjects without experience performing endoscopic surgery, computer-simulated training or any 3-D video system were recruited and divided into two groups (Group A and Group B) for performing two different tasks. The novel 4.7-mm-diameter stereoendoscope provided high-definition (HD) images. In Task 1, Group A started the task under the 3-D condition followed by the 2-D condition, and Group B vice versa. In Task 2, Group A started the task under the 2-D condition followed by the 3-D condition, and Group B vice versa. The performance accuracy and speed under the two visual conditions were analyzed. RESULTS: Significant improvement in performance accuracy and speed was seen under 3-D conditions in the both "3-D first" and "2-D first" subgroups during both tasks (P < .001). Regardless of order, the inaccuracy rate and performance time under 3-D conditions was significantly lower than that under 2-D conditions in each subject. CONCLUSIONS: We demonstrated the advantage of 3-D visualization over 2-D visualization for inexperienced subjects. Further quantitative clinical studies are required to confirm whether stereoendoscopy actually provides benefits in clinical settings.