Cadherin-dependent adhesion of human U373MG glioblastoma cells promotes neurite outgrowth and increases migratory capacity. Laboratory investigation.

OBJECT: The current management of primary CNS tumors involves a multimodal approach, incorporating cytoreductive techniques including resection, radiotherapy, and antiproliferative chemotherapeutic agents. Despite these attempts, the majority of patients with a diagnosis of a high-grade glioma have a dismal prognosis, with the leading cause of treatment failure and tumor recurrence attributable to local invasion of adjacent brain parenchyma. The current study examines the capacity of glioma tumor cells to undergo neurite outgrowth and local migration, specifically focusing on the role of the cadherin cell adhesion system. METHODS: Using a recombinant cadherin ectodomain protein, U373MG human glioblastoma cells were assessed for their ability to adhere and migrate in a cadherin-dependent manner in culture. Adhesion was evaluated via growth assessment and neurite length at 72 hours growth on an immobilized cadherin substrate and compared with other matrix adhesion proteins, such as Type IV collagen and vitronectin. Migratory capacity was measured via modified transwell assays, also using recombinant cadherin ectodomain in comparison with collagen and vitronectin. Results Cadherin adherent cells adopt a fasciculated morphology, with a significant increase in neurite extension, measuring 104 ± 13.3 µm in length, compared with background adhesion on bovine serum albumin and nonfunctional cadherin ectodomain controls measuring 55 ± 4.4 and 47 ± 3.84 µm, respectively (p = 0.029). Significant increases in neurite length compared with controls were also observed in the vitronectin (81 ± 4.69 µm) and Type IV collagen (91 ± 7.7 µm) groups (p = 0.017 and 0.025, respectively). With respect to migration, U373 cells demonstrate increased invasion in response to cadherin ectodomain exposure, whereas vitronectin and Type IV collagen were not potent initiators of migration through the transwell barrier. Both adhesion and migration outcomes were noted in the absence of any relative changes in cell proliferation, indicating a primary role for the cadherin-based adhesion system in tumor invasion. CONCLUSIONS: Cadherin-based adhesion promotes increased adhesion, neurite outgrowth, and migration in human U373MG glioblastoma cells, providing a novel area of research for the development of therapeutic targets addressing local tumor invasion.

Molecular biology of unreresectable meningiomas: implications for new treatments and review of the literature.

Even though meningiomas are most often benign tumors, they can be locally invasive and can develop in locations that prevent surgical treatment. The molecular and biologic factors underlying meningioma development are only now beginning to be understood. Genetic factors such as mutations in the neurofibromatosis-2 gene and in chromosomes 1, 9, and 10 play important roles in meningioma development and may be responsible for atypical tumors in some cases. Cellular factors such as telomerase activation and tyrosine kinase receptor mutations may also play an important role. Finally, autocrine and paracrine factors including epidermal growth factor receptor, platelet-derived growth factor-1, and fibroblast growth factor have been implicated in the development of some tumors. Although the relationship between the various factors implicated in tumor development is unknown, understanding these factors will be critical in the treatment of malignant or surgically inaccessible tumors.

Long-term outcomes and prognostic factors in pediatric patients with severe traumatic brain injury and elevated intracranial pressure.

OBJECT: The management strategies and outcomes in pediatric patients with elevated intracranial pressure (ICP) following severe traumatic brain injury (TBI) are examined in this study. METHODS: This study was a retrospective review of a prospectively acquired pediatric trauma database. More than 750 pediatric patients with brain injury were seen over a 10-year period. Records were retrospectively reviewed to determine interventions for correcting ICP, and surviving patients were contacted prospectively to determine functional status and quality of life. Only patients with 2 years of follow-up were included in the study. RESULTS: Ninety-six pediatric patients (age range 3-18 years) were identified with a Glasgow Coma Scale score<8 and elevated ICP>20 mm Hg on presentation. The mean injury severity score was 65 (range 30-100). All patients were treated using a standardized head injury protocol. The mean time course until peak ICP was 69 hours postinjury (range 2-196 hours). Intracranial pressure control was achieved in 82 patients (85%). Methods employed to achieve ICP control included maximal medical therapy (sedation, hyperosmolar therapy, and paralysis) in 34 patients (35%), ventriculostomy in 23 patients (24%), and surgery in 39 patients (41%). Fourteen patients (15%) had refractory ICP despite all interventions, and all of these patients died. Seventy-two patients (75%) were discharged from the hospital, whereas 24 (25%) died during hospitalization. Univariate and multivariate analysis revealed that the presence of vascular injury, refractory ICP, and cisternal effacement at presentation had the highest correlation with subsequent death (p<0.05). Mean follow-up was 53 months (range 11-126 months). Three patients died during the follow-up period (2 due to infections and 1 committed suicide). The mean 2-year Glasgow Outcome Scale score was 4 (median 4, range 1-5). The mean patient competency rating at follow-up was 4.13 out of 5 (median 4.5, range 1-4.8). Univariate analysis revealed that the extent of intracranial and systemic injuries had the highest correlation with long-term quality of life (p<0.05). CONCLUSIONS: Controlling elevated ICP is an important factor in patient survival following severe pediatric TBI. The modality used for ICP control appears to be less important. Long-term follow-up is essential to determine neurocognitive sequelae associated with TBI.