Naoki Yajima

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.

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.

Induction of autophagy in temozolomide treated malignant gliomas

Autophagy is a dynamic process of protein degradation. Induction of autophagy by temozolomide (TMZ) has been noted in glioma cell lines. Twenty‐eight specimens, obtained from 14 patients before and after TMZ treatment, were analyzed to investigate whether induction of autophagy could be detected in surgical specimens by immunohistochemical analysis. Macroautophagy was monitored by immunohistochemical analysis employing anti‐light chain 3 isoform B (LC3B) and anti‐lysosome‐associated membrane protein 1 (LAMP1) antibodies; chaperone‐mediated autophagy was monitored by anti‐LAMP2A antibody immunostaining. Furthermore, detection of LC3B protein by Western blotting was performed on six specimens obtained from the preserved frozen tissues of three patients. All specimens showed dot‐like staining for each immunostain in the cytoplasm of glioma cells, indicating induction of autophagy. LC3B, LAMP1 and LAMP2A immunostains were semiquantitatively scored from 1 to 3 points. Combination of the three scores after TMZ treatment (6.4 ± 1.2) showed a significant increase (P = 0.020) compared to pre‐treatment scores (5.2 ± 1.5). Western blotting for LC3B showed increased LC3B‐I and LC3B‐II expression after TMZ treatment. The present study proved that autophagy monitoring by immunohistochemical staining of surgical specimens was feasible. These results suggest that autophagy is induced by TMZ.

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.

Results of Treatment of 112 Cases of Primary CNS Lymphoma

BACKGROUND Chemotherapy with or without radiotherapy is the mainstay of treatment for primary central nervous system lymphoma (PCNSL). High-dose methotrexate (MTX) is the most effective drug available to treat these lesions, either as a single agent or in combination with other drugs. Due to the lack of well-conducted randomized trials, the optimal treatment remains controversial. Available retrospective studies are difficult to discuss, however, some common themes can be found. METHODS One hundred and twelve patients with PCNSL were treated with four different regimens over a period of 24 years. Treatment regimens were: whole-brain irradiation (WBI) alone, MVP (MTX, vincristine, and predonisolone), ProMACE-MOPP hybrid (cyclophosphamide, pirarubicin, etoposide, vincristine, procarbazine, prednisone, and MTX) and R-MTX (rituximab, MTX, pirarubicin, procarbazine, and prednisone) combined-modality therapy. RESULTS The median failure-free survival was 16 months, and the median overall survival (OS) was 24 months. The 2- and 5-year actuarial probability of survival was 52.4 +/- 4.8% [95% confidence intervals (CI)] and 30.2 +/- 4.8% (95% CI), respectively. The ProMACE-MOPP protocol, Karnofsky performance status (KPS), MTX dose and WBI were associated with good OS by univariate models. By multivariate analysis, MTX dose, WBI dose, and its square dose were significantly associated with good OS. 20-30 Gy WB, and 500 mg/m(2) of MTX dose appeared important determinants of OS. CONCLUSIONS A modest dose of MTX (500 mg/m(2)) followed by reduced-dose WBI for patients who respond appears a feasible treatment approach that minimizes serious toxicity.

Clinical factors predicting outcomes after surgical resection for sporadic cerebellar hemangioblastomas.

OBJECTIVE To determine whether various clinical factors are related to long-term outcomes of patients with sporadic cerebellar hemangioblastomas. METHODS Subjects included 36 patients (19 men and 17 women) who underwent resection of sporadic hemangioblastoma in the cerebellum. Age at surgery ranged from 17-79 years (mean, 49.7 years). The tumor size, which was defined as the largest diameter of the lesion including the extratumoral cyst, ranged from 10-67 mm (mean, 36.4 mm). Obstructive hydrocephalus secondary to mass effect on the fourth ventricle was present in 21 (58.3%) patients preoperatively. RESULTS Total tumor removal was achieved in 31 of 36 patients (86%). In 4 (11%) patients with solid tumors, postoperative hematoma occurred in the removal cavity, and hematoma removal was required immediately after surgery. We followed 30 patients for >12 months after the initial surgery (mean, 72.9 months; range, 12-274 months). Recurrence of hemangioblastoma developed in 4 of 30 patients (13%) at 6 months, 17 months, 6 years, and 22 years after surgery. At the final follow-up examination, 9 (30%) of 30 patients showed some residual neurologic symptoms (poor group), whereas the remaining 21 patients showed no deficits (good group). Using univariate analysis, both age at surgery and tumor characteristics (cystic or solid) were significantly related to long-term patient outcomes (P < 0.05). However, in a multiple logistic regression analysis, only tumor characteristics were correlated with outcomes (P = 0.017). At the final follow-up examination, patients with solid tumors more frequently showed poor outcomes than patients with cystic tumors. CONCLUSIONS The solid configuration observed on preoperative images of sporadic cerebellar hemangioblastomas is one of the most important clinical factors related to both immediate and long-term outcomes after surgery.

Gene expression signature-based prognostic risk score in patients with primary central nervous system lymphoma.

Purpose: Better understanding of the underlying biology of primary central nervous system lymphomas (PCNSL) is critical for the development of early detection strategies, molecular markers, and new therapeutics. This study aimed to define genes associated with survival of patients with PCNSL. Experimental Design: Expression profiling was conducted on 32 PCNSLs. A gene classifier was developed using the random survival forests model. On the basis of this, prognosis prediction score (PPS) using immunohistochemical analysis is also developed and validated in another data set with 43 PCNSLs. Results: We identified 23 genes in which expressions were strongly and consistently related to patient survival. A PPS was developed for overall survival (OS) using a univariate Cox model. Survival analyses using the selected 23-gene classifiers revealed a prognostic value for high-dose methotrexate (HD-MTX) and HD-MTX–containing polychemotherapy regimen–treated patients. Patients predicted to have good outcomes by the PPS showed significantly longer survival than those with poor predicted outcomes (P < 0.0001). PPS using immunohistochemical analysis is also significant in test (P = 0.0004) and validation data set (P = 0.0281). The gene-based predictor was an independent prognostic factor in a multivariate model that included clinical risk stratification (P < 0.0001). Among the genes, BRCA1 protein expressions were most strongly associated with patient survival. Conclusion: We have identified gene expression signatures that can accurately predict survival in patients with PCNSL. These predictive genes should be useful as molecular biomarkers and they could provide novel targets for therapeutic interventions. Clin Cancer Res; 18(20); 5672–81. ©2012 AACR.

Salvage therapy and late neurotoxicity in patients with recurrent primary CNS lymphoma treated with a modified ProMACE-MOPP hybrid regimen

We report the efficacy of salvage therapy with a modified ProMACE-MOPP combined with radiation in patients with primary central nervous system lymphoma (PCNSL). Thirty-two immunocompetent patients were treated with a regimen of pirarubicin, cyclophosphamide, etoposide, vincristin, and methotrexate (MTX: 500 mg/m2) administered in 21-day cycles. Patients received 20 Gy of whole-brain radiotherapy after three cycles of chemotherapy. A single cycle of chemotherapy was repeated every four months for two years. Nine patients with CNS relapse were retreated with additional cycles of the ProMACE-MOPP hybrid regimen with a 90% objective response rate. Median complete response (CR) duration was 13.2 months and median survival time (MST) for the nine patients treated after initial relapse was 30 months. One of 17 patients (5.8%) who had less than 20 Gy of whole brain irradiation developed dementia. In contrast, six of seven (85.7%) patients who had more than 30 Gy of whole brain radiotherapy became demented. Maintaining a moderate dose of MTX, while adding chemotherapeutic agents and 20 Gy of whole brain radiation therapy, improved disease control and overall survival and lowered the incidence of delayed neurologic toxicity in patients with PCNSL. Additional treatment with a ProMACE-MOPP hybrid regimen is still effective for relapsed disease.

Gene expression signature-based prognostic risk score in patients with glioblastoma

The present study aimed to identify genes associated with patient survival to improve our understanding of the underlying biology of gliomas. We investigated whether the expression of genes selected using random survival forests models could be used to define glioma subgroups more objectively than standard pathology. The RNA from 32 non‐treated grade 4 gliomas were analyzed using the GeneChip Human Genome U133 Plus 2.0 Expression array (which contains approximately 47 000 genes). Twenty‐five genes whose expressions were strongly and consistently related to patient survival were identified. The prognosis prediction score of these genes was most significant among several variables and survival analyses. The prognosis prediction score of three genes and age classifiers also revealed a strong prognostic value among grade 4 gliomas. These results were validated in an independent samples set (n = 488). Our method was effective for objectively classifying grade 4 gliomas and was a more accurate prognosis predictor than histological grading.