Genomic medicine advances for brain tumors.

Cancer genome profiling has revealed important genetic alterations that serve as prognostic indicators and guides for treatment decisions, enabling precision medicine. The shift to molecular diagnosis of brain tumors, as reflected in the 2021 World Health Organization Classification of Tumors of the Central Nervous System, is a crucial role for treatment decision-making. This review discusses the significance and role of cancer genome profiling in precision medicine for malignant brain tumors, particularly gliomas. Furthermore, we explore the progress in cancer genome analysis, focusing on cancer gene panel testing, integration of genomic information in brain tumor classification, and hereditary tumors. Additionally, we discuss the transformative effect of genomic medicine on early detection, risk assessment, and precision medicine strategies. The tumor mutational burden in brain tumors is considered low, but the application of molecular targeted drugs, such as isocitrate dehydrogenase inhibitors, v-raf murine sarcoma viral oncogene homolog B1 inhibitors, fibroblast growth factor receptor inhibitors, neurotrophic tyrosine receptor kinase, mechanistic target of rapamycin inhibitors, and anti-programmed death receptor-1 antibody drugs are promising for glioma treatment. We also discuss the future prospects of molecular targeted drugs.

Mesenchymal stem cells as therapeutic vehicles for glioma.

Glioma is a disease with a poor prognosis despite the availability of multimodality treatments, and the development of novel therapies is urgently needed. Challenges in glioma treatment include the difficulty for drugs to cross the blood-brain barrier when administered systemically and poor drug diffusion when administered locally. Mesenchymal stem cells exhibit advantages for glioma therapy because of their ability to pass through the blood-brain barrier and migrate to tumor cells and their tolerance to the immune system. Therefore, mesenchymal stem cells have been explored as vehicles for various therapeutic agents for glioma treatment. Mesenchymal stem cells loaded with chemotherapeutic drugs show improved penetration and tumor accumulation. For gene therapy, mesenchymal stem cells can be used as vehicles for suicide genes, the so-called gene-directed enzyme prodrug therapy. Mesenchymal stem cell-based oncolytic viral therapies have been attempted in recent years to enhance the efficacy of infection against the tumor, viral replication, and distribution of viral particles. Many uncertainties remain regarding the function and behavior of mesenchymal stem cells in gliomas. However, strategies to increase mesenchymal stem cell migration to gliomas may improve the delivery of therapeutic agents and enhance their anti-tumor effects, representing promising potential for patient treatment.

Dolichoectasia of the ophthalmic artery: a case report on the treatment strategy in endovascular therapy and literature review.

BACKGROUND: Dolichoectasia is a rare arterial condition characterized by the dilatation, tortuosity, and elongation of cerebral blood vessels. The vertebrobasilar artery and internal carotid artery are the common sites of dolichoectasia. However, dolichoectasia of the branch arteries, such as the ophthalmic artery (OA), is extremely rare. To the best of our knowledge, this is the first case of ophthalmic dolichoectasia that was successfully treated with endovascular internal coil trapping. CASE PRESENTATION: A 54-year-old female patient presented with transient left ophthalmalgia and visual disturbance. Magnetic resonance imaging revealed a dilated and elongated left OA compressing the optic nerve at the entrance of the optic canal. However, a previous image that was taken 17 years back revealed that the OA was normal, which suggested the change in dolichoectasia was acquired. Cerebral angiography showed that the dilated and tortuous OA was running from the ophthalmic segment of the left internal carotid artery into the orbit. The symptoms could have been attributed to the direct compression of the dolichoectatic OA in the optic canal. A sufficient anastomosis between the central retinal artery and the middle meningeal artery was identified on external carotid angiography with balloon occlusion of the internal carotid artery. Endovascular treatment with internal trapping of the OA was performed due to ophthalmic symptom progression. Internal coil trapping of the OA was performed at the short segment between the OA bifurcation and the entrance of the optic canal. As expected, the central retinal artery was supplied via the middle meningeal artery after the treatment. The transient visual disturbance was immediately resolved. Ophthalmalgia worsened temporarily after the treatment. However, it completely resolved after several days of oral corticosteroid therapy. Postoperative angiography showed that the origin of the OA was occluded and that the OA in the optic canal was shrunk. The flow of the central retinal arteries via the middle meningeal artery was preserved. CONCLUSIONS: OA dolichoectasia is rare, and its pathogenesis and long-term visual prognosis are still unknown. However, endovascular therapy can improve symptom by releasing the pressure site in the optic canal.

Potent bystander effect and tumor tropism in suicide gene therapy using stem cells from human exfoliated deciduous teeth.

Herpes simplex virus thymidine kinase (HSVTK)/ganciclovir (GCV) suicide gene therapy has a long history of treating malignant gliomas. Recently, stem cells from human exfoliated deciduous teeth (SHED), which are collected from deciduous teeth and have excellent harvestability, ethical aspects, and self-renewal, have been attracting attention mainly in the field of gene therapy. In the present study, we assessed SHED as a novel cellular vehicle for suicide gene therapy in malignant gliomas, as we have previously demonstrated with various cell types. SHED was transduced with the HSVTK gene (SHEDTK). In vitro experiments showed a significant bystander effect between SHEDTK and glioma cell lines in coculture. Furthermore, apoptotic changes caused by caspase 3/7 activation were simultaneously observed in SHEDTK and glioma cells. Mice implanted with a mixture of U87 and SHEDTK and treated with intraperitoneal GCV survived for longer than 100 days. Additionally, tumors in treatment model mice were significantly reduced in size during the treatment period. SHEDTK implanted at the contralateral hemisphere migrated toward the tumor crossing the corpus callosum. These results suggested that SHEDTK-based suicide gene therapy has potent tumor tropism and a bystander-killing effect, potentially offering a new promising therapeutic modality for malignant gliomas.

Efficacy of HSV-TK/GCV system suicide gene therapy using SHED expressing modified HSV-TK against lung cancer brain metastases.

Lung cancer is one of the most common cancers, and the number of patients with intracranial metastases is increasing. Previously, we developed an enzyme prodrug suicide gene therapy based on the herpes simplex virus thymidine kinase (HSV-TK)/ganciclovir (GCV) system using various mesenchymal stem cells to induce apoptosis in malignant gliomas through bystander killing effects. Here, we describe stem cells from human exfoliated deciduous teeth (SHED) as gene vehicles of the TK/GCV system against a brain metastasis model of non-small cell lung cancer (NSCLC). We introduced the A168H mutant TK (TKA168H) into SHED to establish the therapeutic cells because of the latent toxicity of wild type. SHED expressing TKA168H (SHED-TK) exhibited chemotaxis to the conditioned medium of NSCLC and migrated toward implanted NSCLC in vivo. SHED-TK demonstrated a strong bystander effect in vitro and in vivo and completely eradicated H1299 NSCLC in the brain. SHED-TK cells implanted intratumorally followed by GCV administration significantly suppressed the growth of H1299 and improved survival time. These results indicate that the TKA168H variant is suitable for establishing therapeutic cells and that intratumoral injection of SHED-TK followed by GCV administration may be a useful strategy for therapeutic approaches.

Molecular Mechanisms and Clinical Challenges of Glioma Invasion.

Glioma is the most common primary brain tumor, and its prognosis is poor. Glioma cells are highly invasive to the brain parenchyma. It is difficult to achieve complete resection due to the nature of the brain tissue, and tumors that invade the parenchyma often recur. The invasiveness of tumor cells has been studied from various aspects, and the related molecular mechanisms are gradually becoming clear. Cell adhesion factors and extracellular matrix factors have a strong influence on glioma invasion. The molecular mechanisms that enhance the invasiveness of glioma stem cells, which have been investigated in recent years, have also been clarified. In addition, it has been discussed from both basic and clinical perspectives that current therapies can alter the invasiveness of tumors, and there is a need to develop therapeutic approaches to glioma invasion in the future. In this review, we will summarize the factors that influence the invasiveness of glioma based on the environment of tumor cells and tissues, and describe the impact of the treatment of glioma on invasion in terms of molecular biology, and the novel therapies for invasion that are currently being developed.

Migration Capacity of Stem Cells from Human Exfoliated Deciduous Teeth Towards Glioma.

BACKGROUND: Stem cells from human exfoliated deciduous teeth (SHED) are a mesenchymal stem cell type and have recently attracted attention for their high proliferative rate, multipotency, and immunosuppressive properties. However, SHED have not yet been investigated for anticancer properties. We therefore investigated whether SHED can be used as a treatment modality, particularly for anti-glioma therapy. METHODS: In vitro, we examined the mobility of SHED and their ability to migrate towards glioma-conditioned medium and specific growth factors secreted by malignant gliomas. In vivo, we transplanted SHED into the left hemisphere of nude mice that had been previously implanted with human malignant glioma U87 cells into the right hemisphere. We assessed whether SHED had tumorigenic potential. RESULTS: SHED exhibited strong migration ability towards malignant glioma in both in vitro and in vivo assays. In vitro, SHED migrated towards glioma-conditioned medium and specific growth factors such as stem cell factor, platelet-derived growth factor BB, C-X-C motif chemokine ligand 12, and vascular endothelial growth factor. SHED were accumulated around tumor cells in the contralateral hemisphere 1 week after transplantation. Moreover, SHED remained in the brains of nude mice 150 days after transplantation. Finally, we verified that SHED had no malignant transformation or engraftment of SHED in the mouse brain. CONCLUSIONS: Our findings indicate that SHED can potentially be applied to track malignant glioma.

Acute and chronic hemorrhage from radiation-induced cavernous malformation associated with late-delayed radiation necrosis in long surviving glioma patients: A case report.

Although radiation therapy is a standard treatment strategy for patients with glioma, its delayed complications are not clearly understood. Radiation-induced cavernous malformation (RICM) is one of the complications in the delayed phase following radiation therapy, which usually occurs in children. Herein we present three cases of RICM with radiation necrosis in long surviving adult glioma patients, 2 with oligoastrocytoma and one with anaplastic ependymoma. Two of three patients had received an obvious overdose of radiation by additional stereotactic radiation therapy. Repeated episodes of either acute or chronic hemorrhages from RICM worsened the neurological symptoms in all cases. The interval between the last irradiation and the occurrence of symptoms was 45-173 months. The presence of hypointense rim on FLAIR or T2* on magnetic resonance imaging, which resembles the appearance of sporadic cavernous malformations, could be helpful in differentiating RICM from tumor recurrence. Surgical resection was effective in alleviating the symptoms. Microscopically, RICM is a vascular lesion with vulnerable vessels, which are observed in the center of the radiation necrosis. Repeated hemorrhages from these vessels cause either gradual or sudden worsening of neurological symptoms. Therefore, radiation overdose, which results in radiation injury, should be avoided in low grade glioma patients, who could potentially survive for a long period.

Cosmetic and Neuroprotective Placement of Custom-Made Ultra-High-Molecular-Weight Polyethylene Cranial Plate (SKULPIO) in Single-Step Surgery: Technical Note and Case Report.

BACKGROUND: Cranioplasty is a common procedure in neurosurgery. However, cosmetic and neuroprotective reconstructions are necessary after cranioplasty. Treatment of patients with a meningioma with bone infiltration requires removal of the tumor-infiltrated bone and subsequent cranioplasty. We report an efficient technique for cosmetic and neuroprotective reconstructions using a custom-made ultra-high-molecular-weight polyethylene cranial plate (SKULPIO, Kyocera Medical, Kyoto, Japan) in a single-step surgery involving tumor removal and skull reconstruction. METHODS: We present 2 illustrative cases of a 49-year-old female with a right frontal convexity meningioma and 69-year-old male with a bilateral parasagittal atypical meningioma, both involving extensive skull invasion. We preoperatively planned craniotomy size to facilitate the removal of the tumor-infiltrated skull bone using the patients' 3-dimensional cranial models followed by the construction of a custom-made cranial plate. After tumor removal, we drilled out the outer table and the diploe of the cranial edge until the custom-made bone plate accurately fit the bone defect. Finally, the cranial plate was fixed using titanium plates and screws. RESULTS: Postoperative magnetic resonance imaging for each case revealed total meningioma removal and an aesthetically reconstructed skull. Using this technique, precise adjustment of the cranial edge to the plate contributes to a gapless and aesthetic reconstruction. Furthermore, the intact inner table of the skull firmly supports the custom-made bone plate. CONCLUSIONS: This technique involving the placement of a custom-made cranial plate during a single-step surgery was found to be efficient for cosmetic and neuroprotective reconstructions.

"Pure" Suprasellar Schwannoma Presented with Communicating Hydrocephalus: A Case Report.

Schwannoma is a benign peripheral nerve sheath tumor originating from Schwann cells. Most intracranial schwannomas arise from vestibular nerve and schwannoma in the suprasellar region is extremely rare. A 64-year-old man presented with walking disturbance and blurred vision for three months. Lateral hemianopsia in the left eye and brachybasia were observed. Magnetic resonance imaging revealed a suprasellar tumor with strong contrast enhancement associated with communicating hydrocephalus. The cerebrospinal fluid tap test improved gait disturbance. Hypothalamic stimulation test revealed hypo-reaction of GH, FSH and LH. After ventriculo-peritoneal shunting, the tumor was totally removed via a bilateral front-basal approach with a clinical diagnosis of craniopharyngioma. No adhesion was observed between the tumor and surrounding structures such as meninges and brain. The histopathological diagnosis was schwannoma. Here we report a case of suprasellar schwannoma associated with communicating hydrocephalus that has not ever been previously reported, with special reference to its pathogenesis.

Nanoporous Structure Formation in GaSb, InSb, and Ge by Ion Beam Irradiation under Controlled Point Defect Creation Conditions.

Ion beam irradiation-induced nanoporous structure formation was investigated on GaSb, InSb, and Ge surfaces via controlled point defect creation using a focused ion beam (FIB). This paper compares the nanoporous structure formation under the same extent of point defect creation while changing the accelerating voltage and ion dose. Although the same number of point defects were created in each case, different structures were formed on the different surfaces. The depth direction density of the point defects was an important factor in this trend. The number of point defects required for nanoporous structure formation was 4 × 1022 vacancies/m² at a depth of 18 nm under the surface, based on a comparison of similar nanoporous structure features in GaSb. The nanoporous structure formation by ion beam irradiation on GaSb, InSb, and Ge surfaces was controlled by the number and areal distribution of the created point defects.

[Hemodialysis Increases the Incidence of Post-Traumatic Seizure in Hemodialysis Patients with Traumatic Intracranial Hemorrhage].

BACKGROUND: In Japan, the number of hemodialysis patients increases every year, along with the average age of this patient population. Further, certain complications of hemodialysis make the care of traumatic head injury(THI)patients particularly difficult. OBJECTIVE: This study was aimed at investigating the occurrence of and risk factors for post-traumatic seizures in hemodialysis patients with a history of THI, and determining patient outcomes. METHODS: Subjects were selected from patients who were admitted to Yaizu Municipal Hospital in Shizuoka, Japan for traumatic intracranial hemorrhage(TICH). Retrospective medical histories of TICH patients who were and were not receiving hemodialysis were reviewed to investigate the risk factors for seizures and to determine patient outcomes. RESULTS: We identified 18 THI patients on hemodialysis and 86 THI patients not on hemodialysis treatment. We determined that predictive factors of post-traumatic seizure include:current hemodialysis treatment, enlargement of an existing hematoma, and an acute subdural hematoma. Moreover, 66.7% of seizures in our dialysis patients occurred during hemodialysis. Our data also suggest that Glasgow Coma Scale(GCS)scores on admission are a predictive factor for patient outcomes following discharge. CONCLUSION: Current hemodialysis treatment, enlargement of an existing hematoma, and an acute subdural hematoma are predictive factors of seizure occurrence in THI patients. As post-traumatic seizures triggered unfavorable outcomes in some dialysis patients, it is important to create appropriate plans for preventing dialysis disequilibrium syndrome that may lead to seizures in TICH/TIH patients on hemodialysis. We also determined that a low GCS score upon admission is a significant predictor of unfavorable outcomes.

The efficacy of resection of an intradural extramedullary foramen magnum cavernous malformation presenting with repeated subarachnoid hemorrhage: a case report.

BACKGROUND: Intradural extramedullary cavernous angiomas of the central nervous system are a rare type of cavernous angioma, but they can cause fatal subarachnoid hemorrhage. The efficacy of resection for this type of cavernous malformations remains uncertain. This is the first report to recommend surgical resection of these types of lesions regardless of the fatal condition. CASE PRESENTATION: Our patient was a 70-year-old Japanese man who experienced a sudden onset of an occipital headache, followed by bilateral abducens nerve palsy. Magnetic resonance imaging revealed a small amount of hemorrhage in both of the lateral ventricles and an intradural extramedullary mass lesion in the left side of his foramen magnum. Two weeks after the appearance of initial symptoms, he became comatose. A computed tomography scan showed an increase in the subarachnoid intraventricular hemorrhaging and of the acute hydrocephalus. Following ventricular drainage, total tumor resection was performed using the lateral suboccipital transcondylar approach in conjunction with a first cervical hemilaminectomy. We observed a grape-like vascular-rich tumor with calcification that was adhering tightly to the wall of his left vertebral artery. A histopathological examination of the surgery specimen identified it as a cavernous angioma. After placement of a ventriculoperitoneal shunt and 2 months of rehabilitation, he recovered completely. CONCLUSIONS: An intradural extramedullary foramen magnum cavernous malformation is quite rare. The fragile surface of our patient's lesion was causing repeated subarachnoid hemorrhage and consequently progressive fatal neurological deterioration. Surgical resection of the lesion to prevent repeated hemorrhage was performed and he recovered fully. Therefore, we recommend surgical resection of the lesion regardless of the potentially fatal condition.