Shigeo Ueda

Identification of differentially expressed and developmentally regulated genes in medulloblastoma using suppression subtraction hybridization

To increase our understanding of the molecular pathogenesis of medulloblastoma (MB), we utilized the technique of suppression subtractive hybridization (SSH) to identify genes that are dysregulated in MB when compared to cerebellum. SSH-enriched cDNA libraries from both human and Ptch+/− heterozygous murine MBs were generated by subtracting common cDNAs from corresponding non-neoplastic cerebellum. For the human classic MB library, total human cerebellar RNA was used as control tissue; for the Ptch+/− heterozygous MB, non-neoplastic cerebellum from an unaffected Ptch+/− littermate was used as the control. Through differential screening of these libraries, over 100 upregulated tumor cDNA fragments were isolated, sequenced and identified with the NCBI BLAST program. From these, we selected genes involved in cellular proliferation, antiapoptosis, and cerebellar differentiation for further analysis. Upregulated genes identified in the human MB library included Unc33-like protein (ULIP), SOX4, Neuronatin (NNAT), the mammalian homologue of Drosophila BarH-like 1(BARHL1), the nuclear matix protein NRP/B (ENC1), and the homeobox OTX2 gene. Genes found to be upregulated in the murine MB library included cyclin D2 (Ccnd2), thymopoietin (Tmpo), Musashi-1 (Msh1), protein phosphatase 2A inhibitor-2 (I-2pp2a), and Unc5h4(D). Using semiquantitative reverse transcription–polymerase chain reaction (RT–PCR), the mRNA expression levels for these genes were markedly higher in human MBs than in cerebellum. Western blot analysis was used to further confirm the overexpression of a subset of these genes at the protein level. Notch pathway overactivity was demonstrated in the TE671 MB cell line expressing high levels of MSH1 through HES1-Luciferase transfections. This study has revealed a panel of developmentally regulated genes that may be involved in the pathogenesis of MB.

Expression of MAGE and GAGE genes in medulloblastoma and modulation of resistance to chemotherapy

OBJECT Cancer testis antigens (CTAs) were initially identified by their ability to elicit autologous T-cell-mediated immune responses in patients with melanoma. The CTA genes are widely expressed in a variety of human cancers, such as melanoma, breast cancer, lung cancer, esophageal cancer, and hepatocellular carcinoma; however, their expression in pediatric brain tumors, such as medulloblastoma (MB), has not been the subject of in-depth analysis. The MAGE proteins are members of the CTA family and have been shown to correlate with tumor development, aggressive clinical course, or resistance to chemotherapeutic agents. The authors undertook this study to examine the expression and role of MAGE proteins in human MB cell lines and specimens. METHODS From a transcriptional profiling study in which 47,000 genes in MB cell lines were examined, the authors identified members of the MAGE and GAGE families as being highly expressed. A series of MB tumors was examined using both immunohistochemistry and Western blot analysis with antibodies to the MAGE-A family, MAGE-A1, and GAGE proteins. RESULTS Western blot analysis showed expression of these 3 proteins (MAGE-A family, MAGE-A1, and GAGE) in 62, 46, and 84%, respectively, of MB specimens examined. In addition, a correlation was observed between the expression of MAGE and GAGE genes and resistance of MB cells to chemotherapeutic agents. The functional significance of this correlation was examined in MAGE knockdown studies, and increased drug-induced cytotoxicity was observed in UW426 MB cells following treatment with chemotherapeutic drugs. Cleaved caspase-3 was found in UW426/MAGE small interfering (si)RNA-inhibited cells treated with cisplatin, but not in UW426 cells treated with cisplatin alone at the same concentration. CONCLUSIONS These data show that MAGE and GAGE family members are expressed in MB cell lines and specimens, and that inhibition of MAGE and GAGE genes by siRNA increases apoptosis of MB cells and sensitizes them to certain chemotherapeutic agents such as cisplatin and etoposide.

Advances in the treatment of pediatric brain tumors

Brain tumors are a heterogeneous group of neoplasms with different origins, pathobiologies, treatments and prognoses. The collective contributions from the fields of neuro-oncology, neurosurgery, radiation oncology, neurology, neuropathology, neuroradiology and molecular biology have all led to significant advances in the treatment of certain brain tumors. Ideas from these fields, under the cooperative umbrella of clinical cancer trial consortia, have been tested in large-scale studies. As a result, patient survivals have increased markedly for these tumor types. Unfortunately, there are certain brain tumors in childhood, such as the diffuse intrinsic pontine glioma and atypical teratoid rhabdoid tumor, for which survival advantages have not been found. This review will discuss the current and possible future therapies of the most common pediatric brain tumors and highlight some of the novel imaging modalities that are used pre- and intraoperatively.

Surgical Treatment for Occipital Condyle Fracture, C1 Dislocation, and Cerebellar Contusion with Hemorrhage after Blunt Head Trauma.

Occipital condyle fractures (OCFs) have been treated as rare traumatic injuries, but the number of reported OCFs has gradually increased because of the popularization of computed tomography (CT) and magnetic resonance imaging (MRI). The patient in this report presented with OCFs and C1 dislocation, along with traumatic cerebellar hemorrhage, which led to craniovertebral junction instability. This case was also an extremely rare clinical condition in which the patient presented with traumatic lower cranial nerve palsy secondary to OCFs. When the patient was transferred to our hospital, the occipital bone remained defective extensively due to surgical treatment of cerebellar hemorrhage. For this reason, concurrent cranioplasty was performed with resin in order to fix the occipital bone plate strongly. The resin-made occipital bone was used to secure a titanium plate and screws enabled us to perform posterior fusion of the craniovertebral junction. Although the patient wore a halo vest for 3 months after surgery, lower cranial nerve symptoms, including not only neck pain but also paralysis of the throat and larynx, improved postoperatively. No complications were detected during outpatient follow-up, which continued for 5 years postoperatively.

Simultaneous discovery of cranial and spinal intradural chordomas: case report.

The present case illustrates the unexpected occurrence of intradural chordomas that were simultaneously discovered in cranial and spinal locations. A 63-year-old female presented with weakness in the left upper extremity. The patient visited a local doctor and underwent brain computerized tomography (CT). CT revealed a brain tumor, and she was referred to our hospital. Brain magnetic resonance imaging (MRI) demonstrated a midline intradural retroclival tumor in addition to an intradural extramedullary mass lesion at the level of C1–C2. The patient developed a spastic gait disturbance that forced her to use a cane. She underwent laminectomy at C1–C2 along with total removal of the tumor and showed no remarkable symptoms after surgery. Histopathological examination confirmed the diagnosis of chordoma. One month after the cervical surgery, the intracranial tumor was subtotally removed in intracranial surgery via the right subtemporal approach. Histopathological data were identical to that of the cervical tumor. The patient consulted another hospital and underwent gamma-knife surgery. Her neurological examination is relatively unchanged 20 months after the cervical surgery. This case suggests that neuroradiological evaluation should also be performed for an intradural spinal chordoma when an intracranial chordoma is detected. Careful determination of the tumor responsible for the symptoms is necessary if an intradural spinal chordoma is simultaneously detected with an intracranial chordoma.

Incidental Detection of Primary Spinal Malignant Melanoma before Central Nervous System Dissemination

The present case illustrates the incidental detection of a primary malignant melanoma of the thoracic spinal cord before central nervous system dissemination. A 54-year-old female fell down and bruised the thoracolumbar region. The patient visited a local doctor and underwent magnetic resonance imaging (MRI) of the thoracic and lumbar spine to rule out vertebral fractures. MRI revealed no vertebral fracture, but an intradural extramedullary mass was observed at the T12 level. She was referred to our hospital in October 2008. MRI showed that the mass appeared hyperintense on T1-weighted images and hypointense on T2-weighted images. T1-weighted MRI with gadolinium showed a mild homogeneous enhancement of the lesion. The patient underwent laminectomy at T11–L1, along with the complete removal of the tumor, and she exhibited no remarkable symptoms after surgery. Histopathological examination confirmed the diagnosis of malignant melanoma. Malignant melanoma was not detected elsewhere in the body. Neither radiotherapy nor chemotherapy was performed after surgery. Her neurological examination was unremarkable 5 years after the surgery and no tumor recurrence was detected. The present case suggests that patients with primary spinal malignant melanoma may survive >5 years without recurrence after complete surgical removal of the tumor alone. Complete removal of the tumor before central nervous system dissemination may be critical for treatment in such cases. Precise diagnosis via MRI may increase the detection of primary spinal malignant melanoma before central nervous system dissemination, thus facilitating prompt surgical removal, improving the prognosis of patients.

A Case of Atopic Myelitis with Cervical Cavernous Angioma

Atopic myelitis, a type of myelitis which appears in patients with elevated serum levels of immunoglobulin E (IgE), occurs more commonly in the cervical spinal cord, but this mechanism has not yet been elucidated. Herein, we experienced a case of atopic myelitis developed during the growth of cervical cavernous angioma caused by bleeding. A 37-year-old woman suffered from hand swelling caused by a house cat licking. At the same time when cavernous angioma had grown, she experienced a numbness in her four extremities, and multifocal peritumoral hyperintense spinal cord signals were seen. The diagnosis of atopic myelitis was made because we observed significantly elevated levels of specific IgE antibody to cat dander. Symptoms disappeared immediately after steroid pulse therapy. We subsequently resected a cavernous angioma, and eosinophil invasion was found inside it. This is the first case report of atopic myelitis which developed in association with spinal cord vascular lesions. A local blood-brain barrier breakdown due to hemorrhagic lesions of the spinal cord may have contributed to the onset of atopic myelitis.