Ryuya Yamanaka

Vaccination of recurrent glioma patients with tumour lysate-pulsed dendritic cells elicits immune responses: results of a clinical phase I/II trial

In this Phase I/II trial, the patients peripheral blood dendritic cells were pulsed with an autologous tumour lysate of the glioma. Seven patients with glioblastoma and three patients with anaplastic glioma, ranging in age from 20 to 69 years, participated in this study. The mean numbers of vaccinations of tumour lysate-pulsed dendritic cells were 3.7 times intradermally close to a cervical lymph node, and 3.2 times intratumorally via an Ommaya reservoir. The percentage of CD56-positive cells in the peripheral blood lymphocytes increased after immunisation. There were two minor responses and four no-change cases evaluated by radiological findings. Dendritic cell vaccination elicited T-cell-mediated antitumour activity, as evaluated by the ELISPOT assay after vaccination in two of five tested patients. Three patients showed delayed-type hypersensitivity reactivity to the autologous tumour lysate, two of these had a minor clinical response, and two had an increased ELISPOT result. Intratumoral CD4+ and CD8+ T-cell infiltration was detected in two patients who underwent reoperation after vaccination. This study demonstrated the safety and antitumour effects of autologous tumour lysate-pulsed dendritic cell therapy for patients with malignant glioma.

Immunologic Evaluation of Personalized Peptide Vaccination for Patients with Advanced Malignant Glioma

Purpose: The primary goal of this phase I study was to assess the safety and immunologic responses of personalized peptide vaccination for patients with advanced malignant glioma. Experimental Design: Twenty-five patients with advanced malignant glioma (8 grade 3 and 17 grade 4 gliomas) were evaluated in a phase I clinical study of a personalized peptide vaccination. For personalized peptide vaccination, prevaccination peripheral blood mononuclear cells and plasma were provided to examine cellular and humoral responses to 25 or 23 peptides in HLA-A24+ or HLA-A2+ patients, respectively; then, only the reactive peptides (maximum of four) were used for in vivo administration. Results: The protocols were well tolerated with local redness and swelling at the injection site in most cases. Twenty-one patients received more than six vaccinations and were evaluated for both immunologic and clinical responses. Increases in cellular or humoral responses specific to at least one of the vaccinated peptides were observed in the postvaccination (sixth) samples from 14 or 11 of 21 patients, respectively. More importantly, significant levels of peptide-specific IgG were detected in the postvaccination tumor cavity or spinal fluid of all of the tested patients who showed favorable clinical responses. Clinical responses were 5 partial responses, 8 cases of stable disease, and 8 cases of progressive disease. The median overall survival for patients with recurrent glioblastoma multiforme in this study (n = 17) was 622 days. Conclusions: Personalized peptide vaccinations were recommended for the further clinical study to malignant glioma patients.

EphA4 promotes cell proliferation and migration through a novel EphA4-FGFR1 signaling pathway in the human glioma U251 cell line

The Eph receptor tyrosine kinases and their ephrin ligands form a unique cell-cell contact-mediated bidirectional signaling mechanism for regulating cell localization and organization. High expression of Eph receptors in a wide variety of human tumors indicates some roles in tumor progression, which makes these proteins potential targets for anticancer therapy. For this purpose, we did gene expression profiling for 47 surgical specimens of brain tumors including 32 high-grade glioma using a microarray technique. The analysis, focused on the receptor tyrosine kinases, showed that EphA4 mRNA in the tumors was 4-fold higher than in normal brain tissue. To investigate the biological significance of EphA4 overexpression in these tumors, we analyzed EphA4-induced phenotypic changes and the signaling mechanisms using human glioma U251 cells. EphA4 promoted fibroblast growth factor 2-mediated cell proliferation and migration accompanied with enhancement of fibroblast growth factor 2-triggered mitogen-activated protein kinase and Akt phosphorylation. In addition, active forms of Rac1 and Cdc42 increased in the EphA4-overexpressing cells. Furthermore, we found that EphA4 formed a heteroreceptor complex with fibroblast growth factor receptor 1 (FGFR1) in the cells and that the EphA4-FGFR1 complex potentiated FGFR-mediated downstream signaling. Thus, our results indicate that EphA4 plays an important role in malignant phenotypes of glioblastoma by enhancing cell proliferation and migration through accelerating a canonical FGFR signaling pathway. [Mol Cancer Ther 2008;7(9):2768–78]

Identification of expressed genes characterizing long-term survival in malignant glioma patients

Better understanding of the underlying biology of malignant gliomas is critical for the development of early detection strategies and new therapeutics. This study aimed to define genes associated with survival. We investigated whether genes coupled with a class prediction model could be used to define subgroups of high-grade gliomas in a more objective manner than standard pathology. RNAs from 29 malignant gliomas were analysed using Agilent microarrays. We identified 21 genes whose expression was most strongly and consistently related to patient survival based on univariate proportional hazards models. In six out of 10 genes, changes in gene expression were validated by quantitative real-time PCR. After adjusting for clinical covariates based on a multivariate analysis, we finally obtained a statistical significance level for DDR1 (discoidin domain receptor family, member 1), DYRK3 (dual-specificity tyrosine-(Y)-phosphorylation-regulated kinase 3) and KSP37 (Ksp37 protein). In independent samples, it was confirmed that DDR1 protein expression was also correlated to the prognosis of glioma patients detected by immunohistochemical staining. Furthermore, we analysed the efficacy of the short interfering RNA (siRNA)-mediated inhibition of DDR1 mRNA synthesis in glioma cell lines. Cell proliferation and invasion were significantly suppressed by siRNA against DDR1. Thus, DDR1 can be a novel molecular target of therapy as well as an important predictive marker for survival in patients with glioma. Our method was effective at classifying high-grade gliomas objectively, and provided a more accurate predictor of prognosis than histological grading.

Cell-and peptide-based immunotherapeutic approaches for glioma

Glioblastoma multiforme (GBM) is the most common and lethal primary malignant brain tumor. Although considerable progress has been made in surgical and radiation treatment for glioma patients, the impact of these advances on clinical outcome has been disappointing. Therefore, the development of novel therapeutic approaches is essential. Recent reports demonstrate that systemic immunotherapy using dendritic cells (DCs) or peptide vaccines is capable of inducing an antiglioma response. These approaches successfully induce an antitumor immune response and prolong survival in patients with glioma without major side effects. There are several types of glioma, so to achieve effective therapy, it might be necessary to evaluate the molecular genetic abnormalities in individual patient tumors and design novel immunotherapeutic strategies based on the pharmacogenomic findings. Here, we review recent advances in DC- and peptide-based immunotherapy approaches for patients with gliomas.

Induction of therapeutic antitumor antiangiogenesis by intratumoral injection of genetically engineered endostatin-producing Semliki Forest virus.

Antiangiogenic therapy using Semliki Forest virus (SFV) carrying Endostatin gene for malignant brain tumor was investigated to improve the therapeutic efficacy. The efficiency of SFV-mediated gene delivery was first evaluated for B 16 cells and compared with the efficiency in cells of endothelial origin (HMVECs). HMVECs are more susceptible to SFV infection than B 16 cells. For the in vivo treatment model, phosphate-buffered saline, SFV-LacZ, retrovirus vector GCsap-Endostatin, and SFV-Endostatin were injected to mice bearing B 16 brain tumors. A very significant inhibition of tumor growth was observed in the group that had been treated with SFV-Endostatin. A marked reduction of intratumoral vascularization was seen in the tumor sections from the SFV-Endostatin group compared with tumor sections from the SFV-LacZ or GCsap-Endostatin groups. Moreover, at day 7 after intravenous administration of SFV-Endostatin, the serum level of endostatin was augmented more than 3-fold compared to that after intravenous administration of GCsap-Endostatin. The results indicated that treatment with SFV-Endostatin inhibited the angiogenesis with established tumors. Gene therapy with Endostatin delivered via SFV may be a candidate for the development of new therapy for brain tumors. Cancer Gene Therapy (2001) 8, 796–802

Assessment of immunological biomarkers in patients with advanced cancer treated by personalized peptide vaccination

To investigate immunological biomarkers to predict overall survival of advanced cancer patients under treatment with personalized peptide vaccination, correlations between overall survival and biomarkers, including cytotoxic T lymphocyte (CTL) and immunoglobulin G (IgG) responses to the vaccinated peptides, were investigated in 500 advanced cancer patients who received personalized peptide vaccination from October 2000 to October 2008. The best clinical response was assessed for in 436 patients, 43 patients (10%) had partial response, 144 patients (33%) had stable disease and 249 patients (57%) had progressive, with a median overall survival of 9.9 months. Both lymphocyte counts prior to the vaccination (P = 0.0095) and increased IgG response (P = 0.0116) to the vaccinated peptides, along with performance status (P < 0.0001), well correlated with overall survival. To confirm the superiority of IgG response to CTL response, the samples from advanced castration-resistant prostate cancer patients who survived more than 900 days (n=20) and those who died within 300 days (n=23) were analyzed further. As a result, both the numbers of peptides, to which increased IgG responses were observed, and the fold increases in IgG levels were significantly higher in long-term survivors (P = 0.000282 and P = 0.00045). In contrast, CTL responses were not statistically different between the two groups. Both lymphocyte numbers and IgG response were thus suggested to be biomarkers of cancer vaccine for advanced cancer patients.

Dendritic-cell- and peptide-based vaccination strategies for glioma

Despite advances in radiation and chemotherapy along with surgical resectioning, the prognosis of patients with malignant glioma is poor. Therefore, the development of a new treatment modality is extremely important. There are increasing reports demonstrating that systemic immunotherapy using dendritic cells and peptide is capable of inducing an antiglioma response. This review highlights dendritic-cell- and peptide-based immunotherapy for glioma patients. Dendritic-cell- and peptide-based immunotherapy strategies appear promising as an approach to successfully induce an antitumor immune response and increase survival in patients with glioma. Dendritic cell- and peptide-based therapy of glioma seems to be safe and without major side effects. There are several types of glioma; so to achieve effective therapy, it may be necessary to evaluate the molecular genetic abnormalities in individual patient tumors and design novel immunotherapeutic strategies based on the pharmacogenomic findings. Here, in this review, recent advances in dendritic-cell- and peptide-based immunotherapy approaches for patients with gliomas are discussed.

Tumor lysate and IL-18 loaded dendritic cells elicits Th1 response, tumor-specific CD8+ cytotoxic T cells in patients with malignant glioma

In this study, we demonstrate that tumor lysate-loaded dendritic cells can elicit a specific CD8+ cytotoxic T lymphocyte response against autologous tumor cells in patients with malignant glioma. CTL from three of five patients expressed strong cytolytic activity against autologous glioma cells, did not lyse autologous lymphoblasts and were variably cytotoxic against the LAK-sensitive cell line Daudi. Also, DCs pulsed normal brain lysate failed to induce cytolytic activity against autologous glioma cells, suggesting the lack of autoimmune response. Two of five patients CD8+ T cells expressed a modest cytotoxicity against autologous glioma cells. CD8+ T cells isolated during these ineffective primings secreted large amounts of IL-10, less amounts of IFN-γ as detected by ELISA, Type 2 bias in the CD8+ T cell response accounts for the lack of cytotoxic effector function from these patients. Cytotoxicity against autologous glioma cells could be significantly inhibited by anti-HLA class I antibody. These data demonstrate that tumor lysate-loaded DC can be an effective tool in inducing glioma-specific CD8+ CTL able to kill autologous glioma cells in vitro. However, high levels of tumor specific tolerance in some patients may account for a significant barrier to therapeutic vaccination. Moreover, cytotoxic responses were augmented by transfecting DC with the gene for IL-18. For all five patients, CD8+T cells treated with IL18 transfected DC produced Th1 response. These results may have important implications for the treatment of malignant glioma patients with immunotherapy. DCs loaded with total tumor lysate and IL-18 may represent a method for inducing Th1 immunoresponses against the entire repertoire of glioma antigens.

Growth inhibition of human glioma cells modulated by retrovirus gene transfection with antisense IL-8

The human glioma cell line, NP-1, expresses IL-8 mRNA and constitutively secretes IL-8 protein. Administration of recombinant IL-8 increased the proliferation of NP-1 cells in a dose-dependent manner. In the presence of anti-IL-8 antiserum, the IL-8 mediated proliferation of NP-1 cell growth was inhibited. Further, NP-1 cell growth was inhibited by transfection of retroviral constructs encoding antisense IL-8 bothin vitro andin vivo models. These results suggest that antisense IL-8 gene therapy could be beneficial in gliomas where autocrine stimulation by IL-8 is implicated.