Abstract: Cell division is an elemental process, and mainly consists of chromosome segregation and subsequent cytokinesis. Some errors in this process have the possibility of leading to carcinogenesis. Aurora-B is known as a chromosomal passenger protein that regulates cell division. In our previous studies of giant cell glioblastoma, we reported that multinucleated giant cells resulted from aberrations in cytokinesis with intact nuclear division occurring in the early mitotic phase, probably due to Aurora-B dysfunction. In this study, as we determined p53 gene mutation occurring in multinucleated giant cell glioblastoma, we investigated the role of Aurora-B in formation of multinucleated cells in human neoplasm cells with various p53 statuses as well as cytotoxity of glioma cells to temozolomide (TMZ), a common oral alkylating agent used in the treatment of gliomas. The inhibition of Aurora-B function by small-interfering (si)RNA led to an increase in the number of multinucleated cells and the ratios of G2/M phase in p53-mutant and p53-null cells, but not in p53-wild cells or the cells transduced adenovirally with wild-p53. The combination of TMZ and Aurora-B-siRNA remarkably inhibited the cell viability of TMZ-resistant glioma cells. Accordingly, our results suggested that Aurora-B dysfunction increases in the appearance of multinucleated cells in p53 gene deficient cells, and TMZ treatment in combination with the inhibition of Aurora-B function may become a potential therapy against p53 gene deficient and chemotherapeutic-resistant human gliomas.

Abstract: PURPOSE: Methylation of the O(6)-methyguanine-DNA methyltransferase (MGMT) gene promoter in gliomas has been reported to be a useful predictor of the responsiveness to temozolomide (TMZ). In our previous experiments, we observed that IFN-beta sensitized TMZ-resistant glioma cells with the unmethylated MGMT promoter and that the mechanism of action was possibly due to attenuation of MGMT expression via induction of TP53. In this study, (1) we explored the synergistic effect of IFN-beta and TMZ in the animal model, and (2) clarified the role of IFN-beta induced TP53 in the human MGMT promoter. METHODS: (1) Nude mice with either subcutaneous T98 (TMZ-resistant) or U251SP (TMZ-sensitive) tumor were treated with IFN-beta/TMZ for 5 consecutive days. (2) The MGMT promoter activity was assayed by a luciferase reporter system in Saos2 (p53-null) cells transduced with a p53-adenoviral vector, and T98 glioma cells treated with IFN-beta. RESULTS: (1) A combination of IFN-beta/TMZ had significant synergistic antitumor activity on the growth of both T98 and U251SP tumors. (2) MGMT promoter activity was suppressed by either adenovirally transduced p53 or IFN-beta. CONCLUSIONS: It would be appealing to consider a prospective clinical trial in which genetic markers are used for personalized drug selection, eliciting other forms of treatment or inhibition of MGMT for those with MGMT expression. In this context, IFN-beta inactivates MGMT via p53 gene induction and enhances the therapeutic efficacy to TMZ.

Abstract: Neural stem cell (NSC) transplantation has exhibited considerable therapeutic potential in spinal cord injury. However, most experiments in animals have been performed by injecting these cells directly into the injured spinal cord. A cardinal feature of NSCs is their exceptional migratory ability through the nervous system. Based on the migratory ability of NSCs, we investigated whether minimally invasive intravenous delivery of NSCs could facilitate their migration to the injured spinal cord and identified the chemo-attractants secreted by the lesions. Nude mice were injected intravenously with labelled human NSCs at 3, 7 and 10 days after the compression of the spinal cord at the T8 level. The migration of NSCs to the lesioned spinal cord was highest at 7 days after injury; this correlated with the peak of hepatocyte growth factor and stromal cell-derived factor-1 mRNA expressions in the lesion but not with the disruption of the blood-brain barrier. Finally, the grafted NSCs differentiated into neuronal and glial subpopulations at 21 days after transplantation. Our study suggests that intravenously administered NSCs can be employed as a renewable source for replacing lost cells for the treatment of spinal cord injuries.

Abstract: OBJECTIVE: Intratumor heterogeneity is of great importance in many clinical aspects of glioma biology, including tumor grading, therapeutic response, and recurrence. Modifications in the genetic features of a specific primary tumor recurring after chemo- and radiotherapy are poorly understood. We report a recurrent glioblastoma case exhibiting loss of heterozygosity (LOH) on chromosome 10q, while the primary tumor exhibited heterogeneity in the LOH status of 1p, 19q, and 10q. To determine the relationship between such modifications and heterogeneous chemosensitivity, primary cultured cells heterogeneously showing 1p/19q/10q losses were established from a surgical specimen of oligoastrocytoma and were treated with chemotherapeutic agents. CLINICAL PRESENTATION: A 46-year-old woman with a 1-month history of headache and visual disturbances presented to our institution. INTERVENTION: A right temporoparietal craniotomy and gross total resection were performed. The pathological diagnosis was glioblastoma multiforme with oligodendroglial components. Whereas LOH on 10q was identified at all tumor sites, only the oligodendroglial components exhibited LOH on 1p and 19q. The tumor recurred 6 months after postoperative chemotherapy using interferon-beta and ranimustine, as well as a course of fractionated external-beam radiotherapy (total dose, 60 Gy). Gene analysis revealed no 1p/19q allelic losses but only 10q LOH. CONCLUSION: Intratumor heterogeneity might be explained by the presence of more than one subclone in the primary tumor. Here, the tumor cells exhibiting 1p/19q LOH with high chemosensitivity might have been killed by the adjuvant therapy and those exhibiting 10q LOH with chemoresistance recurred. This study and our preliminary laboratory findings might suggest an approach to brain tumor physiology, diagnosis, and therapy.

Abstract: Medulloblastomas are highly malignant neuroectodermal cerebellar tumors of children. One of the reasons for the difficulty for the treatment of medulloblastomas is their inherent tendency to metastasize through the cerebrospinal fluid (CSF) pathway leading to leptomeningeal dissemination. Recently, genetically modified neural stem cells (NSCs) were shown to have the capability of selectively migrating into glioma mass and delivering therapeutic agents with significant therapeutic benefits. In the present study, we applied the NSC strategy to target medulloblastomas, particularly their leptomeningeal dissemination. We used NSCs that were retrovirally transduced with the cytosine deaminase gene (CD-NSCs). In vitro studies demonstrated that CD-NSCs had sufficient migratory activity toward medulloblastoma cells and exerted a remarkable bystander effect on these cells following the application of 5-fluorocytosine (5-FC). It is noteworthy that neutralization of the hepatocyte growth factor blocked their migration In animal studies using our leptomeningeal dissemination model, CD-NSCs implanted directly into CSF space were shown to distribute diffusely within the disseminated tumor cells and could provide remarkable antitumor effect after intraperitoneal administration of 5-FC. Furthermore, CD-NSC treatment followed by 5-FC administration prolonged survival periods significantly in experimental animals. Our data suggest that the CD-NSC strategy can also be applied to target leptomeningeal dissemination of medulloblastomas.

Abstract: OBJECT: Analysis of meningiomas supports the suggestion that loss of heterozygosity (LOH) of chromosome arm 1p plays an important role in malignancy. The aim of this study was to identify genes related to meningioma progression from the benign state to the atypical and anaplastic states by examining 1p LOH and the promoter methylation of RASSF1A and p73. METHODS: The authors studied 40 surgical specimens (22 WHO Grade I, 11 Grade II, and seven Grade III) obtained in 37 patients with meningioma. The LOH at 1p36 was analyzed using microsatellite markers, and promoter methylation of p73 and RASSFIA was analyzed using methylation-specific polymerase chain reaction. RESULTS: No 1p LOH was detected in the Grade I tumors, whereas it was detected in more than 80% of the Grade II and III tumors. Methylation of the p73 promoter was observed in 81.8 and 71.4% of the Grade II and III tumors, respectively, but it was not observed in any of the Grade I tumors; methylation of the RASSF1A promoter was observed in 18.2, 63.6, and 42.9% of the Grade I, II, and III tumors, respectively. Interestingly, 1p LOH and p73 promoter hypermethylation were detected in the malignantly transformed tumors but not in the lower-grade primary ones. CONCLUSIONS: Based on the hypothesis that meningiomas cumulatively acquire genetic alterations and thus progress from the benign to the atypical and anaplastic states, genetic alterations in the methylation status of p73 or RASSF1A along with 1p LOH may result in the malignant transformation of a meningioma. This type of genetic fingerprint may play both diagnostic and therapeutic roles.

Abstract: Promoter methylation of the deoxyribonucleic acid (DNA) repair gene, O(6)-methylguanine-DNA methyltransferase (MGMT), is associated with improved outcome of patients with glioblastoma multiforme and anaplastic astrocytoma treated with temozolomide (TMZ). Molecular genetic analysis of loss of heterozygosity (LOH) of 1p, 19q, or 10q, p53 mutation, and MGMT promoter methylation was performed in 44 assessable tumor specimens obtained from 46 patients with recurrent malignant gliomas, including 21 with glioblastoma multiforme, 17 with anaplastic astrocytoma, and eight with anaplastic oligoastrocytoma, which have heterogeneous features and variable histological diagnosis, to assess the correlation with the response to TMZ. LOHs of 1p and 19q, and MGMT promoter methylation showed positive correlations with the clinical response to TMZ therapy (p < 0.005, 0.05, and 0.05, respectively; Fisher's exact test). In addition, LOH of 1p and MGMT promoter methylation were associated with longer progression-free survival (p < 0.05 and 0.05, respectively; Cox regression analysis). LOH of 1p in the heterogeneous population of malignant gliomas may be one of the important factors besides MGMT methylation that predict better outcome in patients treated with TMZ.

Abstract: Recently, it has been elucidated that cognitive dysfunction following cranial radiotherapy might be linked to the oxidative stress-induced impairment of hippocampal neurogenesis that is mediated by proliferating neural stem or progenitor cells. The novel free-radical scavenger edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) has been clinically used to reduce neuronal damage following ischemic stroke. Here, we demonstrate via in vitro studies that edaravone protects human neural stem cells (NSCs) from cell death and restores their differentiation ability after irradiation; however, the protective effect of edaravone is not observed in human brain tumor cells. Our study may shed some light on the beneficial effects of free-radical scavengers in impaired neurogenesis following cranial radiation therapy.

Abstract: Apocrine carcinoma is an extremely rare malignant neoplasm that occurs most frequently in the axilla. Although it usually shows an indolent clinical course, it often metastasizes to regional lymph nodes and sometimes to lungs or bones. However, a literature search did not reveal any report describing the detailed clinical course of brain metastases from apocrine carcinoma. We report a case of a 54-year-old male who suffered from multiple brain metastases from apocrine carcinoma that had originated in the scalp 6 years before. The brain metastases appeared in spite of several regimens of chemotherapy for lung metastases for two years. The tumor in the right frontal lobe was successfully operated. However, the small tumor in the right occipital lobe was not cured by gamma knife surgery, and eventually required second operation. The operation had contributed to his neurologically independent life for about one year until he died for gradual progression of lung metastases. To our knowledge this is the first reported case of metastatic brain tumor from apocrine carcinoma.

Abstract: Glioblastomas are the most common primary brain tumors in adults. These tumors exhibit a high degree of vascularization, and malignant progression from astrocytoma to glioblastoma is often accompanied by increased angiogenesis and the upregulation of vascular endothelial growth factor and its receptors. In this study, we investigated the in vivo antiangiogenic and antitumor effects of brain-specific angiogenesis inhibitor 1 (BAI1) using human glioblastoma cell lines. Glioblastoma cells were transduced with an adenoviral vector encoding BAI1 (AdBAI1), and Northern and Western blot analyses, respectively, demonstrated BAI1 mRNA and protein expression in the transduced tumor cells. Using an in vivo neovascularization assay, we found that angiogenesis surrounding AdBAI1-transduced glioblastoma cells transplanted into transparent skinfold chambers of SCID mice was significantly impaired compared to control treated cells. Additionally, in vivo inoculation with AdBAI1 of established subcutaneous or intracerebral transplanted tumors significantly impaired tumor growth and promoted increased mouse survival. Morphologically, the tumors exhibited signs of impaired angiogenesis, such as extensive necrosis and reduced intratumoral vascular density. Taken together, these data strongly indicate that BAI1 may be an excellent gene therapy candidate for the treatment of brain tumors, especially human glioblastomas.

Abstract: Gefitinib--a specific inhibitor of epidermal growth factor receptor (EGFR)-associated tyrosine kinase--has demonstrated efficacy in a subgroup of patients with non-small-cell lung carcinoma (NSCLC) who fail conventional chemotherapy. It is also reported to have an antitumor effect in brain metastases from NSCLC. Additionally, EGFR mutations have shown a strong association with gefitinib sensitivity for NSCLC. Here, we assessed the efficacy of gefitinib in brain metastases from NSCLC and evaluated the association of this efficacy with EGFR mutations. We retrospectively reviewed eight cases in which patients were suffering from brain metastases before the initiation of gefitinib treatment. Brain tumor response could be evaluated by MRI in these patients; EGFR gene analyses were also available. We evaluated whether objective tumor response was observed after gefitinib treatment and assessed the efficacy of gefitinib as effective, noneffective, or not assessable in consideration of the influence of previous radiotherapy. Of the eight patients, the efficacy of gefitinib was assessed as effective in three and as noneffective in three. All three patients demonstrating effective efficacy had EGFR mutations in the tyrosine kinase domain (deletion mutation in two patients and point mutation in one patients), whereas none of the three patients demonstrating noneffective efficacy had EGFR mutations. Gefitinib appears to be effective in treating brain metastases in a subgroup of patients. Our data suggested a possible association between the efficacy of gefitinib in the treatment of brain metastases and EGFR mutations.

Abstract: This chapter outlines the current clinical application of interferon for treatment of brain tumor, especially glioma. Since approved as a therapeutic drug for brain tumor originally produced in Japan, interferon-beta has been reported to be effective when it was used alone, in combination with chemo-radiotherapy (ACNU/MCNU as a nitrosourea derivative chemodrug, and radiation for 60 Gy totally). Recently, the regimen of combination with interferon-beta have been improved to obtain a higher efficacy rate. For example, as a fundamental study, temozolomide is an enthusiastic chemodrug to enhance the anti-tumor effect of interferon-beta when it is combined, pre-clinical and clinical trial will be scheduled. As for interferon-beta gene therapy by means of liposome as ad drug delivery system, already clinical trial has been performed and clinical safety and effectiveness have been proved, and it is expected that newly development in the field of gene therapy will be established and improvement of therapeutic results for malignant brain tumor will be achieved.

Abstract:

Abstract: The skulls of 1195 Japanese serow (Capricornis crispus) from six geographically distinct populations were examined for tooth rotation. Our objectives were to determine tooth rotation patterns in Japanese serows, investigate geographical variation in tooth rotation and examine whether space limitations in the jaw accounted for variations. We then sought to explain the origin of tooth rotation in the Japanese serow. Rotated teeth were found in 131 specimens (62 males, 57 females and 12 unknown gender), with no statistically significant difference between males and females (chi(2)=0.03, P=0.86, d.f.=1). Among the six populations, the frequency of tooth rotation varied from 3.7-32.1% (average 11.0%). Most tooth rotation occurred in the upper third and fourth premolars. The lingual cusp of anomalous teeth was rotated 30 degrees -90 degrees mesially or distally from the buccolingual tooth axis, and the rotation direction differed among populations. However, we found no difference in skull or tooth morphology between normal individuals and those with tooth rotation. Therefore, hereditary factors may be involved in Japanese serow tooth rotation. We concluded that genetic differentiation occurred in the past among local Japanese serow populations isolated in mountainous habitats. Gene frequencies were likely subject to random drift, especially during possible population bottlenecks, when genetic factors could most strongly affect the direction of rotation.

Abstract: A rare case of chordoid meningioma in the lateral ventricle observed in an adult is reported. The first clinical manifestation of the disease was a prolonged fever of unknown origin. Abnormalities in the patient's blood chemistry, principally polyclonal hypergammaglobulinemia (immunoglobulin [Ig]G, IgA, and markedly IgE) and an elevated serum level of C-reactive protein, were associated with the disease. The tumor was histologically confirmed to be a chordoid meningioma, and its surgical removal resulted in complete resolution of the patient's symptoms. By combining reverse transcription-polymerase chain reaction and immunohistochemical analysis, it may be shown that cytokine production, including that of interleukin (IL)-6, IL-1beta, and vascular endothelial growth factor, plays a role in the pathogenesis of chordoid meningioma associated with Castleman syndrome.

Abstract: Alkylating agents, such as temozolomide, are among the most effective cytotoxic agents used for malignant gliomas, but responses remain very poor. The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) plays an important role in cellular resistance to alkylating agents. IFN-beta can act as a drug sensitizer, enhancing toxicity against a variety of neoplasias, and is widely used in combination with other antitumor agents such as nitrosoureas. Here, we show that IFN-beta sensitizes glioma cells that harbor the unmethylated MGMT promoter and are resistant to temozolomide. By means of oligonucleotide microarray and RNA interference, we reveal that the sensitizing effect of IFN-beta was possibly due to attenuation of MGMT expression via induction of the protein p53. Our study suggests that clinical efficacy of temozolomide might be improved by combination with IFN-beta using appropriate doses and schedules of administration.

Abstract: Gene transfer to the nervous system is an attractive option to treat a wide variety of neurological insults. The expression of trophic factor and/or antiapoptotic genes may be beneficial in halting the slow neurodegeneration in such conditions as Parkinson's disease (4,5), the rapid neuronal cell death following trauma to the brain or spinal cord (6,7), or in treating peripheral neuropathies associated with diabetes or use of chemotherapeutic agents (8,9). Introduction of dominant-negative mutant genes or antisense RNA to treat diseases such as Huntington's disease, or transfer of genes to replace lost or mutated endogenous proteins to treat disorders such as lysosomal storage diseases, may prove useful. In addition, gene transfer to overexpress endogenous antinociceptive proteins has great potential in pain management. The problem faced by all of these applications is finding a suitable methodology that will facilitate the transfer of exogenous genes to the appropriate nerve cells; virusbased vectors have proven quite efficient in transferring genes to many different cell types.

Abstract: In this study we investigated the antitumour effect and mechanism of action of cationic liposome-mediated murine interferon-beta (IFNbeta) gene therapy in mouse B16F1 melanoma cells in vitro and in vivo. Murine IFNbeta gene transfer by cationic liposome resulted in substantial growth inhibition of B16F1 melanoma cells in culture when compared with phosphate buffered saline or recombinant murine IFNbeta treatment, or lacZ control gene transfer. Use of video-enhanced contrast-differential interference contrast (VEC-DIC) microscopy revealed that liposomes containing the murine IFNbeta gene [lip(pSV2muIFNbeta)], but not recombinant murine IFNbeta, induced dramatic morphological changes that characterize apoptosis, including bleb formation, shrinkage of cells, nuclear condensation and 'ballooning', in approximately 30% of the cells treated. Intratumoral administration of lip(pSV2muIFNbeta) resulted in a 5.5-fold reduction in the mean volume of subcutaneous melanoma lesions in syngeneic mice 15 days after treatment and eradicated the tumour in 18% of the mice treated. Immunocytochemical analysis demonstrated that a larger number of natural killer (NK) cells infiltrated the tumour following lip(pSV2muIFNbeta) treatment than in controls. In vivo depletion of NK cells using the anti-asialoGM1 antibody reduced the efficacy of lip(pSV2muIFNbeta) treatment. Taken together, our data suggest that cationic liposome-mediated IFNbeta gene therapy could be effective against melanoma by directly inducing cell death and stimulating NK cells.

Abstract: In order to test the functional implication of herpes simplex virus (HSV) vector-mediated gene transfer after axonal injury, we injected replication-incompetent HSV vectors coding for the anti-apoptotic peptide Bcl-2 and the glial cell-derived neurotrophic factor (GDNF), separately or in combination into ventral spinal cord 30 min after a crush injury to the proximal spinal root that was combined with moderate mechanical traction. HSV-mediated expression of Bcl-2 or GDNF enhanced functional recovery assessed by histologic, electrophysiologic, and behavioral parameters up to 5 months after injury. The most sensitive measure of distal motor function, the sciatic function index, was significantly improved in animals injected with the two vectors together. These results suggest an approach to root trauma that might be used to enhance functional recovery after injury.

Abstract: Proximal spinal nerve injury results in the death of motor neurons in ventral horn. We have previously demonstrated this cell death can be prevented by HSV-mediated transfer of the gene coding for the antiapoptotic peptide Bcl-2 7 days prior to injury, but that expression of Bcl-2 does not preserve ChAT expression in the lesioned cells. In the current study, we examined two related issues: whether Bcl-2 delivered by HSV-mediated gene transfer 30 min after injury could similarly protect motor neurons from cell death, and whether the additional HSV-mediated expression of the glial cell derived neurotrophic factor (GDNF) could improve the result. At 30 min after avulsion of the L4, L5, and L6 spinal nerves, replication defective genomic HSV-based vectors coding for Bcl-2, GDNF, a reporter transgene (lacZ), or the Bcl-2 and GDNF vectors together were injected into spinal cord. Transduction of motor neurons with either the Bcl-2-expressing vector or the GDNF-expressing vector resulted in a substantial increase in the number of surviving motor neurons, and coinjection of the two vectors together resulted in cell survival that was similar to the result obtained with either vector alone. Neither the Bcl-2-expressing vector nor the GDNF-expressing vector delivered alone protected choline acetyltransferase (ChAT) expression in lesioned neurons. However, simultaneous injection of the Bcl-2- and the GDNF-expressing vectors together resulted in a substantial increase in the number of ChAT in cells in the lesioned ventral horn. Together, these findings suggest an approach to improving cell survival and regeneration following proximal root injury.

Abstract: Apoptosis is originally defined by unique morphological changes of dying cells, and the biochemical hallmark associated with apoptosis is internucleosomal DNA fragmentation. However, few report has shown the precise time course of the apoptotic events. The present study was designed to try to clarify apoptotic processes using a video-enhanced contrast-differential interference contrast (VEC-DIC) microscopy. The morphological changes of murine fibroblast Ltk-cells treated with TNF-alpha were divided into four stages: (i) pre-apoptotic, (ii) cytoplasmic shrinkage, (iii) membrane blebbing, and (iv) ballooning. Almost of the cells underwent cytoplasmic shrinkage and membrane blebbing within 6 hours after TNF-alpha exposure, and at about 9 hours, they were in the ballooning stage. Based on these data, we investigated the relationship between morphological changes and other biochemical features. The earliest event was exposure of phosphatidyl-serine at the cytoplasmic membrane, which was already observed in the pre-apoptotic stage. Loss of mitochondrial membrane potential was observed in the cytoplasmic shrinkage stage. Caspase-8/-3 activities already started increasing in the pre-apoptotic stage, and reached their peak at 6 hours after TNF-alpha exposure. DNA fragmentation occurred in the late phase of the membrane blebbing.

Abstract: Proximal axotomy in adult animals results in delayed death of motor neurons. Features characteristic of both necrosis and apoptosis have been described in motor neurons of the spinal cord following proximal avulsion of the ventral roots. We have previously demonstrated that a genomic herpes simplex virus (HSV)-based vector expressing the anti-apoptotic peptide Bcl-2 protects dopaminergic neurons of the substantia nigra from neurotoxin-induced apoptotic cell death and preserves the neurotransmitter phenotype of those cells. In this study we examined whether the same vector could protect adult rat lumbar motor neurons from cell death following proximal ventral root avulsion. Injection of the Bcl-2-expressing vector 1 week prior to root avulsion increased the survival of lesioned motor neurons, determined by retrograde Fluorogold labeling, by 50%. The Bcl-2-expressing vector did not preserve choline acetyltransferase neurotransmitter phenotype of the lesioned cells. These results shed light on the mechanism of cell death following axonal injury, and have implications for developing an effective treatment for the clinical problem of proximal root avulsion.

Abstract: Previous studies have demonstrated that either the neurotrophin glial-derived neurotrophic factor (GDNF) or the antiapoptotic peptide Bcl-2 delivered into striatum by a viral vector protects dopaminergic neurons of the substantia nigra in vivo from degeneration induced by the administration of the neurotoxin 6-hydroxydopamine (6-OHDA). In this study we used recombinant, replication-incompetent, genomic herpes simplex virus-based vectors to deliver the genes coding for Bcl-2 and GDNF into rat substantia nigra (SN) 1 week prior to 6-OHDA injection into the striatum. Vector-mediated expression of either Bcl-2 or GDNF alone each resulted in a doubling in cell survival as measured by retrograde labeling with fluorogold (FG) and a 50% increase in tyrosine hydroxylase-immunoreactive (TH-IR) neurons in the lesioned SN compared to the unlesioned side. Gene transfer of Bcl-2 and GDNF were equivalent in this effect. Coadministration of the Bcl-2-expressing vector with the GDNF-expressing vector improved the survival of lesioned SN neurons as measured by FG labeling by 33% and by the expression of TH-IR by 15%. These results suggest that the two factors delivered together act in an additive fashion to improve DA cell survival in the face of 6-OHDA toxicity.

Abstract: Dendritic cells (DCs) are professional antigen-presenting cells (APCs) that locate in peripheral organs. It has been thought that a systemic immune response does not play a role in regression of central nervous system (CNS) tumors, because the CNS is an immunologically privileged site. However, recent advances in immunology have led to the possibility of immunotherapy using peripheral DCs against CNS tumors. Here, we investigated whether DCs pulsed with tumor extract could induce an antitumor effect against malignant glioma. Furthermore, we also investigated whether the antitumor effect become higher by pulsation with tumor extract-liposome complex, compared to pulsation with tumor extract alone. As a liposome, we used cationic small unilamellar vesicles composed of N-(alpha-trimethylammonioacetyl)-didodecyl-D-glutamate chloride (TMAG), dilauroylphosphatidylcholine (DLPC), and dioleoylphosphatidylethanolamine (DOPE) in a molar ratio of 1:2:2. After intracerebral inoculation of mouse malignant glioma GL261 cells into syngeneic C57BL/6 mice, DCs pulsed with extract from the glioma cells by sonication were administered intraperitoneally thrice weekly on days 7, 14 and 21. Tumor growth inhibition was evaluated by measuring the tumor size 1 month after the tumor inoculation. The group treated with DCs pulsed by tumor extract was inhibited in tumor progression compared with the control non-pulsed DCs group, and the group treated with DCs pulsed by tumor extract and liposomes showed substantial tumor volume reductions in all the mice. Among the mice, there were several with no visible masses in their brains. Immunohistochemical study showed that the CD8-positive cytotoxic T cells (CTLs) were strongly recognized among the almost disappearing tumor cells of pulsed DCs groups. The CTLs showed a specific antitumor activity for GL261 mouse glioma cells. These findings indicated that DCs pulsed with tumor extract and liposomes might play an important role in the activation of an immune response in malignant glioma.

Abstract: Adenoviral (Ad) vectors are commonly used in gene therapy trials because of their efficiency in gene transfer. However, their use is limited by immune responses that reduce transgene expression and decrease the efficacy of repeated vector administration. In this study, we demonstrated that conjugation of Ad vector with our novel cationic liposomes could reduce viral antigenicity in vivo. Mice subcutaneously injected with liposome-conjugated Ad vector showed a 6.5-fold reduction of anti-Ad antibodies with neutralizing activity, compared to those with unconjugated Ad vector. Interestingly, we also found that the conjugated vector is less susceptible to inactivation by neutralizing antibodies in vitro and in vivo. Our results suggest that liposome conjugation reduces viral antigenicity, shields vectors from neutralizing antibody, and may allow repeated Ad vector administration.

Abstract: Replication-deficient adenoviral vectors are promising agents for human gene therapy of the greater transduction efficiency than other vectors. However, there are distinct disadvantages, including high immunogenicity, which limits the administration to human organs, particularly the brain. Injection of adenoviral vectors into the human brain causes inflammatory responses and induces cerebral edema. The combined effect of adenoviral vectors and cationic liposomes in vitro was investigated in an effort to reduce the immune reaction against the antigens of adenoviral vectors. No toxicity of adenoviral vector-associated liposomes was observed within optimal lipid concentration. The transduction efficiency of the adenoviral vectors containing the beta-galactosidase gene increased almost 10-fold when associated with the cationic liposomes. Furthermore, greater cytotoxicity was induced when the adenoviral vector containing herpes simplex virus-thymidine kinase gene was combined with cationic liposomes than with only the adenoviral vector. These results suggest that the combination of adenoviral vectors and cationic liposomes allows the doses of adenoviral vectors to be reduced while maintaining transduction efficiency.

Abstract: The expression of topoisomerase II alpha (Topo II alpha) was investigated in six human glioma cell lines as a function of doubling time, cell cycle distribution, and sensitivity to an antineoplastic agent, etoposide (ETP). The Topo II alpha level was determined by immunohistochemical and flow cytometric studies using monoclonal antibody, 8D2, specific for Topo II alpha. In all cell lines, the Topo II alpha level correlated directly with sensitivity to ETP, but not with doubling time or percentage of cells in any phase of the cell cycle. These findings suggest that the cytocidal activity of ETP may be mediated by qualitative and quantitative changes in Topo II alpha in human glioma cells. We speculate that better knowledge of Topo II alpha expression in surgical specimens may lead to more individualized use of ETP in patients with malignant glioma.

Abstract: We previously demonstrated that intratumoral administration of liposomes containing the murine interferon beta (IFN-beta) gene [lip(pSV2muIFN-beta)] resulted in stronger growth-inhibitory effect on GL261 (H-2b) mouse glioma inoculated in brains of syngeneic C57BL/6 mice than conventional exogenous IFN-beta administration, and histologic evaluation revealed the massive infiltration of T lymphocytes (CD8 > CD4) within the residual tumor. The present study was aimed at determining whether such tumor-infiltrating lymphocytes (TIL) have any tumor-specific cytotoxic effects. Intratumoral administration of lip(pSV2muIFN-beta) resulted in prolonged survival time and a 50% tumor-free incidence in the mice treated. The surviving animals were subsequently re-challenged with either subcutaneous or intracranial injection of GL261 cells, and no tumors were found to develop over a 50-day period. In vivo depletion of CD8, but not CD4 cells decreased the efficacy of lip(pSV2muIFN-beta). Specific cytotoxic T lymphocytes (CTL) against GL261 cells were generated from both TIL and spleen cells of the mice treated. The results of flow cytometric analysis and antibody blocking test revealed that the bulk CTL lines thus prepared were T cell receptor (TCR) alphabeta, CD8 T lymphocytes with H-2b restriction. These findings suggest that, in addition to direct growth-inhibitory effects by the IFN-beta gene on the tumor cells, activation of systemic cellular immunity may participate in antitumor effects in vivo, despite the fact that central nervous system is generally regarded as an immunologically privileged site.

Abstract: Cationic liposomes containing the human interferon-beta (IFN-beta) gene induce marked growth inhibition in human glioma cells. In vivo experiments using an human glioma implanted into the brains of nude mice have demonstrated a definite growth-inhibitory effect, achieving complete tumor regression with multiple intratumoral injections of the gene. However, nude mouse studies are inadequate to evaluate antitumor effects fully, especially those related to activation of the host immune response. This article aimed to investigate antitumor effects and immune response activation by murine IFN-beta gene transfer in syngeneic mice. In vitro experiments demonstrated a stronger growth-inhibitory effect of liposomes containing the murine IFN-beta gene on a GL261 mouse glioma cell line than exogenously added murine IFN-beta. In in vivo experiments, intratumoral administration of liposomes containing the murine IFN-beta gene resulted in a 16-fold reduction in the mean volume of residual gliomas in the brains of C57BL/6 mice and massive infiltration of cytotoxic T lymphocytes (CTL) within the residual tumor, while few CTL were infiltrated in controls including murine IFN-beta, empty liposomes, naked plasmid expressing murine IFN-beta, and liposomes containing beta-galactosidase gene. In addition, 40% of mice treated with liposomes containing the murine IFN-beta gene were completely cured. These findings indicated that activation of cellular immunity participates in antitumor effects in vivo together with direct effects of the IFN-beta gene.

Abstract: A novel Ca2+/calmodulin-dependent protein kinase II (CaM Kinase II) inhibitor, KN-93 potently inhibits gastric acid secretion from parietal cells. As previously reported (1), treatment of parietal cells with a selective inhibitor of CaM kinase II, KN-62 resulted in the inhibition of cholinergic-stimulated rabbit parietal cell secretion, whereas it failed to inhibit the histamine and forskolin response. In contrast effects of carbachol, histamine and forskolin were significantly inhibited by KN-93 with an IC50 of 0.15, 0.3 and 1 microM, respectively; these effects occurred without any changes in intracellular cyclic AMP and Ca2+ levels. In the present study we investigated the mechanism by which KN-93 acts upon the acid-secreting machinery of gastric parietal cells. Neither redistribution of the proton pump activity nor the morphological transformation were affected by KN-93. The drug only weakly inhibited the H+, K(+)-ATPase activity but strongly dissipated the proton gradient formed in the gastric membrane vesicles and reduced the volume of luminal space. Thus KN-93 acts at pH gradient formation whereas KN-62 acts only at CaM Kinase II.