Tetsuo Hashiba

Phase II clinical trial of Wilms tumor 1 peptide vaccination for patients with recurrent glioblastoma multiforme

OBJECT The object of this study was to investigate the safety and clinical responses of immunotherapy targeting the WT1 (Wilms tumor 1) gene product in patients with recurrent glioblastoma multiforme (GBM). METHODS Twenty-one patients with WT1/HLA-A*2402-positive recurrent GBM were included in a Phase II clinical study of WT1 vaccine therapy. In all patients, the tumors were resistant to standard therapy. Patients received intra-dermal injections of an HLA-A*2402-restricted, modified 9-mer WT1 peptide every week for 12 weeks. Tumor size, which was obtained by measuring the contrast-enhanced area on magnetic resonance images, was determined every 4 weeks. The responses were analyzed according to Response Evaluation Criteria in Solid Tumors (RECIST) 12 weeks after the initial vaccination. Patients who achieved an effective response continued to be vaccinated until tumor progression occurred. Progression-free survival and overall survival after initial WT1 treatment were estimated. RESULTS The protocol was well tolerated; only local erythema occurred at the WT1 vaccine injection site. The clinical responses were as follows: partial response in 2 patients, stable disease in 10 patients, and progressive disease in 9 patients. No patient had a complete response. The overall response rate (cases with complete or partial response) was 9.5%, and the disease control rate (cases with complete or partial response as well as those in which disease was stable) was 57.1%. The median progression-free survival (PFS) period was 20.0 weeks, and the 6-month (26-week) PFS rate was 33.3%. CONCLUSIONS Although a small uncontrolled nonrandomized trial, this study showed that WT1 vaccine therapy for patients with WT1/HLA-A*2402-positive recurrent GBM was safe and produced a clinical response. Based on these results, further clinical studies of WT1 vaccine therapy in patients with malignant glioma are warranted.

Immunohistochemical analysis of adhesion molecules and matrix metalloproteinases in malignant CNS lymphomas: a study comparing primary CNS malignant and CNS intravascular lymphomas

Two distinct forms of malignant lymphomas can invade the central nervous system (CNS). Although primary CNS malignant lymphomas (PCNSMLs) invade the brain parenchyma, intravascular lymphomas (IVLs) form tumor cell aggregates in the vasculature and produce stroke-like symptoms and cognitive impairment. Although the tumor cells are mostly of B-cell origin in both types of lymphoma, their biological behavior is different, and the detailed mechanism(s) underlying this difference are not well understood. We studied the expression level of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1) and integrin-β1 in tumor tissue samples from patients with primary CNS lymphoma (n = 8) and intravascular lymphoma (n = 2) using immunohistochemical analysis. We also assessed the expression of the matrix metalloproteinases (MMP)-2 and MMP-9. ICAM-1 was positive in six and integrin-β1 was positive in seven patients among eight PCNSML patients. MMP-2 and MMP-9 were expressed in all PCNSML. In contrast, none of them was positive in both IVL cases. Our findings suggest that adhesion molecules and MMPs are essential for malignant lymphoma cell invasion from the vasculature into the brain parenchyma and that they may be the key determinants for malignant lymphoma cells to behave as PCNSML or IVL cells.

Detection of genetic and chromosomal aberrations in medulloblastomas and primitive neuroectodermal tumors with DNA microarrays.

Medulloblastoma (MB) is the most frequent infratentorial malignant brain tumor in children. In contrast, primitive neuroectodermal tumor (PNET) is defined as a supratentorial malignant tumor generated from the cerebral hemisphere. These tumors have considerable histological overlap but have different clinical outcomes including overall survival period, recurrence rate, and chemosensitivity. We investigated the amplification and/or deletion of genes and the chromosomal gain and/or loss in 10 MBs and 3 PNETs with a genomic DNA microarray system. Genes that are frequently amplified in these both these tumors include MSH2, N-myc, AKT3, and EGFR. Amplifications of SNRPN, MYB, and PTEN are observed only in MB. The genes associated with Wnt/APC and Shh/PTCH pathways also have some aberrations. Common chromosomal aberrations include gains at 17q and 7q and losses at 17p. Minor chromosomal losses were also detected at 1p, 8p + q, 11p, 10p + q, 13q, 16q, and Xp + q in MB. SPNETs tend to contain fewer chromosomal and genetic abnormalities than MBs. In conclusion, there are gene expression and chromosomal differences between MBs and SPNETs. These differences may correlate with the prognosis.

Scoring radiologic characteristics to predict proliferative potential in meningiomas.

We investigated the feasibility of using radiologic characteristics to predict the proliferative potential in meningiomas. Our statistical analysis revealed that the presence of peritumoral edema, an ambiguous brain–tumor border, and irregular tumor shape were significantly correlated with a higher MIB-1 staining index (SI) value. We developed the following scoring system for specific features in each tumor: peritumoral edema (tumor with edema = 1, tumor without edema = 0); brain–tumor border (tumor with any ambiguous border = 1, tumor circumscribed by a distinct rim = 0); and tumor shape (tumor with irregular shape = 1, tumor with smooth shape = 0). Using Spearmans correlation coefficient analysis, we found a significant correlation (P < 0.005) between total score calculated for each patient and SI value. Our findings suggest that the proliferative potential of meningiomas can be predicted using a less invasive preoperative examination focusing on the presence of peritumoral edema, ambiguous brain–tumor border, and irregular tumor shape.

Chromosomal and genetic aberrations differ with meningioma subtype.

Meningioma is one of the most common brain tumors, and a variety of genetic abnormalities have been detected by the Southern blotting, polymerase chain reaction (PCR), fluorescence in situ hybridization (FISH), and comparative genomic hybridization (CGH) methods. However, these methods detect only a very limited portion of the tumor genome or have a limited mapping resolution. In this study, we used DNA microarray assay, which detects numerous genetic abnormalities and analyzes a global assessment of molecular events in tumor cells. We analyzed genomic DNA from 26 patients with benign meningiomas by GenoSensor Array 300 in order to characterize gene amplifications, gene deletions, and chromosomal information in the whole genome. Loss of chromosome 22q was found most frequently. This chromosomal aberration was detected in 14 meningiomas (53.8%), particularly in transitional and fibrous meningiomas. In meningothelial meningiomas, amplification ofINS andTCL1A was detected more frequently than in other meningioma subtypes. DNA microarray assay revealed new genetic differences among the meningioma subtypes, thus indicating that this novel technique is useful for understanding tumor genesis and for the diagnosis of meningioma subtype.

Skull metastasis from papillary thyroid carcinoma accompanied by neurofibromatosis type 1 and pheochromocytoma: report of a case.

We report here a 74-year-old woman with a skull metastasis from papillary thyroid carcinoma (PTC). In her medical history, she was diagnosed with neurofibromatosis type 1 (NF1) at age 28 years, and she underwent thyroidectomy for PTC at age 52 years and adrenectomy for pheochromocytoma (PC) at age 58 years. She was admitted to our hospital with an increased mass in the forehead. Head computed tomography (CT) showed an expansive, osteolytic, and solid tumor extending from the dura mater into the subcutis, destroying part of the frontal bone. Head magnetic resonance imaging (MRI) revealed that the tumor was chiefly extradural but partially invaded the dura mater. Cerebral angiography showed that the tumor was fed from a branch of the external carotid artery. She underwent surgery, and histological examination revealed that the skull tumor was a metastasis from PTC, indicating that skull metastasis occurred 23 years after curative surgery for PTC. The patient also underwent adjuvant radioiodine therapy. As little is known about skull metastases from PTC, we discuss its characteristics and the extremely rare combined occurrence of PC and PTC in an NF1 patient.

Chromosomal and genetic abnormalities in benign and malignant meningiomas using DNA microarray

Abstract Background: Meningioma is the commonest brain tumor and many genetic abnormalities, such as the loss of chromosome 22q and the mutation of NF2, have been reported. Methods: These classical abnormalities were detected using Southern blot, PCR, fluorescence in situ hybridization and comparative genomic hybridization, but these methods examine only very limited regions or limited mapping resolution of the tumor genome. In this study, we used DNA microarray assay, which detects numerous genetic abnormalities simultaneously and analyses a global assessment of molecular events in meningioma cells. We studied 31 meningiomas by GenoSensor Array 300 in order to detect the chromosomal aberrations and genetic abnormalities in the whole genome. Results: This study demonstrated not only classical chromosomal aberration, such as loss of chromosome 22q in 19 meningiomas (61.3%), but also new genetic characteristics of meningiomas, such as amplification of MSH2 in 16 meningiomas (51.6%), deletion of GSCL in 13 meningiomas (41.9%) and deletion of HIRA in seven meningiomas (22.6%). Conclusions: These results suggest that DNA microarray assay is useful in research for the genetic characters of meningiomas and understanding tumorigenesis.