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Various combination treatments have been considered to attain the effective therapy threshold by combining independent antitumor mechanisms against the heterogeneous characteristics of tumor cells in malignant brain tumors. In this study, the natural killer (NK) cells associated with bevacizumab (Bev) plus irinotecan (Iri) against glioblastoma multiforme (GBM) were investigated. For the experimental design, NK cells were expanded and activated by K562 cells expressing the OX40 ligand and membrane-bound IL-18 and IL-21. The effects of Bev and Iri on the proliferation and NK ligand expression of GBM cells were evaluated through MTT assay and flow cytometry. The cytotoxic effects of NK cells against Bev plus Iri-treated GBM cells were also predicted via the LDH assay in vitro . The therapeutic effect of different injected NK cell routes and numbers combined with the different doses of Bev and Iri was confirmed according to tumor size and survival in the subcutaneous (s.c) and intracranial (i.c) U87 xenograft NOD/SCID IL-12Rγ null mouse model. The presence of injected-NK cells in tumors was detected using flow cytometry and immunohistochemistry ex vivo . As a result, Iri was found to affect the proliferation and NK ligand expression of GBM cells, while Bev did not cause differences in these cellular processes. However, the administration of Bev modulated Iri efficacy in the i.c U87 mouse model. NK cells significantly enhanced the cytotoxic effects against Bev plus Iri-treated GBM cells in vitro. Although the intravenous (IV) injection of NK cells in combination with Bev plus Iri significantly reduced the tumor volume in the s.c U87 mouse model, only the direct intratumorally (IT) injection of NK cells in combination with Bev plus Iri elicited delayed tumor growth in the i.c U87 mouse model. Tumor-infiltrating NK cells were detected after IV injection of NK cells in both s.c and i.c U87 mouse models. In conclusion, the potential therapeutic effect of NK cells combined with Bev plus Iri against GBM cells was limited in this study. Accordingly, further research is required to improve the accessibility and strength of NK cell function in this combination treatment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Tran, Kim, Duong, Thangaraj, Chu, Jung, Kim, Moon, Kim, Lee, Lee, Yun, Lee, Lee, Lee and Jung.)

Emerging data have suggested that single short peptides have limited success as a cancer vaccine; however, extending the short peptides into longer multi-epitope peptides overcame the immune tolerance and induced an immune response. Moreover, the combination of adjuvants such as lenalidomide and anti-programmed cell death protein 1 (PD1) with a peptide vaccine showed potential vaccine effects in previous studies. Therefore, the effects of a long multi-epitope peptide vaccine in combination with lenalidomide and anti-PD1 were analyzed in this study. Long multi-epitope peptides from two MHCI peptides (BIRC5 97-104 and EphA2 682-689 ) and the pan-human leukocyte antigen-DR isotype (HLA-DR) binding epitope (PADRE) were synthesized. The therapeutic effects of long multi-epitope peptides in combination with lenalidomide and anti-PD1 were confirmed in the murine GL261 intracranial glioma model. Immune cells' distribution and responses to the long multi-epitope peptides in combination with these adjuvants were also estimated in the spleens, lymph nodes, and tumor tissues. The difference between long multi-epitope peptides and a cocktail of multi-epitope peptides combined with lenalidomide and anti-PD1 was also clarified. As a result, long multi-epitope peptides combined with lenalidomide and anti-PD1 prolonged the survival of mice according to the suppression of tumor growth in an intracranial mouse model. While long multi-epitope peptides combined with these adjuvants enhanced the percentages of activated and memory effector CD8 + T cells, the increase in percentages of regulatory T cells (Tregs) was observed in a cocktail of multi-epitope peptides combined with lenalidomide and anti-PD1 group in the tumors. Long multi-epitope peptides combined with these adjuvants also enhanced the function of immune cells according to the enhanced pro-inflammatory cytokines and cytotoxicity against GL261 cells in ex vivo . In conclusion, long multi-epitope peptides composed of MHCI peptides, BIRC5 and EphA2, and the MHCII peptide, PADRE, in combination with lenalidomide and anti-PD1 has the potential to improve the therapeutic effects of a vaccine against GBM., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Tran, Kim, Kim, Jung, Kim, Moon, Kim, Lee, Yun, Lee, Lee, Lee and Jung.)

Background: An open-label single-arm phase 2 study was conducted to evaluate the role of levetiracetam as a sensitizer of concurrent chemoradiotherapy (CCRT) for patients with newly diagnosed glioblastoma. This study aimed to determine the survival benefit of levetiracetam in conjunction with the standard treatment for glioblastoma., Methods: Major eligibility requirements included histologically proven glioblastoma in the supratentorial region, patients 18 years or older, and Eastern Cooperative Oncology Group (ECOG) performance status of 0-2. Levetiracetam was given at 1,000-2,000 mg daily in two divided doses during CCRT and adjuvant chemotherapy thereafter. The primary and the secondary endpoints were 6-month progression-free survival (6mo-PFS) and 24-month overall survival (24mo-OS), respectively. Outcomes of the study group were compared to those of an external control group., Results: Between July 2016 and January 2019, 76 patients were enrolled, and 73 patients were included in the final analysis. The primary and secondary outcomes were improved in the study population compared to the external control (6mo-PFS, 84.9% vs. 72.3%, p = 0.038; 24mo-OS, 58.0% vs. 39.9%, p = 0.018), but the differences were less prominent in a propensity score-matched analysis (6mo-PFS, 88.0% vs. 76.9%, p = 0.071; 24mo-OS, 57.1% vs. 38.8%, p = 0.054). In exploratory subgroup analyses, some results suggested that patients with ages under 65 years or unmethylated MGMT promoter might have a greater survival benefit from the use of levetiracetam., Conclusions: The use of levetiracetam during CCRT in patients with newly diagnosed glioblastoma may result in improved outcomes, but further investigations are warranted., (© 2021 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

The promising immunotherapy effects of a multiple antigenic peptide on glioblastoma (GBM) in a previous study encourage the use of adjuvants to enhance its therapeutic efficacy. Among adjuvants, pan HLA-DR-binding epitope (PADRE) and anti-programmed cell death protein 1 (anti-PD1) have potentially been tested for cancer immunotherapy. Therefore, here we evaluated the ability of PADRE and anti-PD1 to enhance the function of the branched multipeptide against GBM. The potential utility of tumor-associated antigens (ErbB-2 and WT-1) targeting GBM with HLA-A24 was confirmed and a branched multipeptide was constructed from these antigens. The effects of the branched multipeptide and PADRE on immunophenotyping and polarized Th cytokine production in dendritic cells were clarified. The expression of PD1 on T cells and PDL1 on GBM cells was also investigated. The interferon-γ enzyme-linked immunospot and lactate dehydrogenase release assays were performed to determine the function of GBM peptide antigen-specific cytotoxic T cells against GBM cells. Overall, this study showed that both ErbB-2 and WT-1 are potential candidates for branched multipeptide construction. The branched multipeptide and PADRE enhanced the expression of major histocompatibility complex and co-stimulatory molecules and the production of polarized Th1 cytokines in dendritic cells. The increase in the number of interferon-γ+ effector T cells was consistent with the increase in the percentage specific lysis of GBM target cells by GBM peptide antigen-specific cytotoxic T cells in the presence of the branched multipeptide, PADRE, and anti-PD1. Our study suggests the combination of branched multipeptide and adjuvants such as PADRE and anti-PD1 can potentially enhance the effects of immunotherapy for GBM treatment., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Recent clinical trials utilizing antigen-pulsed dendritic cells (DCs) have demonstrated increased survival of vaccinated cancer patients. Besides, the cytoplasmic transduction peptide (CTP) not only has an excellent transcellular efficiency but also shows a strong tendency to remain in the cytoplasm after transduction, without migrating into the nucleus. In this study, we investigated the effectiveness of immunotherapy against malignant gliomas using DCs pulsed with CTP-fused protein antigens combined with programmed cell death protein 1 blockade (anti-PD1). The expression of tumor associated antigen (WT1 and BIRC5) and PDL1 on glioblastoma (GBM) target cells was confirmed by western blot. The effect of CTP-fused protein antigens on mature DCs (VaxDCs) was determined. The immunophenotypes of VaxDCs pulsed with CTP-fused protein antigens was confirmed by flow cytometry and the cytokine production levels of T helper polarization were measured by enzyme-linked immunosorbent (ELISA) assay. The IFN-γ-enzyme linked immunospot and lactate dehydrogenase release assays were performed to estimate the cytotoxic activity of antigen-specific cytotoxic T lymphocytes (CTLs), stimulated by VaxDCs pulsed with CTP-fused protein antigens and anti-PD1, against malignant glioma cells expressing target antigens. VaxDCs pulsed with CTP-fused protein antigens showed enhanced expression of major histocompatibility complex (MHC) and co-stimulatory markers of DCs and resulted in Th1 cytokine polarization. The increase in the number of IFN-γ + effector T cells paralleled with the enhanced percent specific lysis of GBM targets cells by antigen-specific CTLs. Our study suggested that using CTP-fused protein antigens for DC vaccine preparation along with PD1 blockade could be an effective immunotherapy strategy for GBM.

Glioblastoma, the most common aggressive cancer, has a poor prognosis. Among the current standard treatment strategies, radiation therapy is the most commonly recommended. However, it is often unsuccessful at completely eliminating the cancer from the brain. A combination of radiation with other treatment methods should therefore be considered. It has been reported that radiotherapy in combination with immunotherapy might show a synergistic effect; however, this still needs to be investigated. In the current study, a "branched multipeptide and peptide adjuvants [such as pan DR epitope (PADRE) and polyinosinic-polycytidylic acid-stabilized with polylysine and carboxymethylcellulose-(poly-ICLC)]," namely vaccine and anti-PD1, were used as components of immunotherapy to assist in the anti-tumor effects of radiotherapy against glioblastomas. With regard to experimental design, immunological characterization of GL261 cells was performed and the effects of radiation on this cell line were also evaluated. An intracranial GL261 mouse glioma model was established, and therapeutic effects were observed based on tumor size and survival time. The distribution of effector immune cells in the spleen, based on cytotoxic T lymphocyte (CTL) and natural killer (NK) cell function, was determined. The pro-inflammatory and anti-inflammatory cytokine production from re-stimulated splenocytes and single tumor cells were also evaluated. As GL261 cells demonstrated both immunological characteristics and radiation sensitivity, they were found to be promising candidates for testing this combination treatment. Combinatorial treatment with radiation, vaccine, and anti-PD1 prolonged mouse survival by delaying tumor growth. Although this combination treatment led to an increase in the functional activity of both CTLs and NK cells, as evidenced by the increased percentage of these cells in the spleen, there was a greater shift toward CTL rather than NK cell activity. Moreover, the released cytokines from re-stimulated splenocytes and single tumor cells also showed a shift toward the pro-inflammatory response. This study suggests that immunotherapy comprising a branched multipeptide plus PADRE, poly-ICLC, and anti-PD1 could potentially enhance the anti-tumor effects of radiotherapy in a glioblastoma mouse model., (Copyright © 2020 Tran, Kim, Duong, Jung, Kim, Moon, Jang, Lee, Lee and Jung.)

Purpose: The purpose of this study was to investigate the feasibility and survival benefits of combined treatment with radiotherapy and adjuvant temozolomide (TMZ) in a Korean sample., Materials and Methods: A total of 750 Korean patients with histologically confirmed glioblastoma multiforme, who received concurrent chemoradiotherapy with TMZ (CCRT) and adjuvant TMZ from January 2006 until June 2011, were analyzed retrospectively., Results: After the first operation, a gross total resection (GTR), subtotal resection (STR), partial resection (PR), biopsy alone were achieved in 388 (51.7%), 159 (21.2%), 96 (12.8%), and 107 (14.3%) patients, respectively. The methylation status of O 6 -methylguanine-DNA methyltransferase (MGMT) was reviewed retrospectively in 217 patients. The median follow-up period was 16.3 months and the median overall survival (OS) was 17.5 months. The actuarial survival rates at the 1-, 3-, and 5-year OS were 72.1%, 21.0%, and 9.0%, respectively. The median progression-free survival (PFS) was 10.1 months, and the actuarial PFS at 1-, 3-, and 5-year PFS were 42.2%, 13.0%, and 7.8%, respectively. The patients who received GTR showed a significantly longer OS and PFS than those who received STR, PR, or biopsy alone, regardless of the methylation status of the MGMT promoter. Patients with a methylated MGMT promoter also showed a significantly longer OS and PFS than those with an unmethylated MGMT promoter. Patients who received more than six cycles of adjuvant TMZ had a longer OS and PFS than those who received six or fewer cycles. Hematologic toxicity of grade 3 or 4 was observed in 8.4% of patients during the CCRT period and in 10.2% during the adjuvant TMZ period., Conclusion: Patients treated with CCRT followed by adjuvant TMZ had more favorable survival rates and tolerable toxicity than those who did not undergo this treatment., Competing Interests: relevant to this article was not reported.

We investigated the use of cytotoxic T-lymphocyte (CTL) epitopes in peptide immunotherapy for glioblastoma. Three peptides (ERBB2, BIRC5 and CD99) were selected based on their peptide-T2 cell binding affinities and combined in a multipeptide cocktail or a branched multipeptide synthesized with mini-polyethylene glycol spacers. Dendritic cells (DCs) pulsed with the multipeptide cocktail or branched multipeptide were compared based on their immunophenotype and cytokine secretion. FACS analysis of alpha-type 1 polarized dendritic cells (αDC1s) revealed that both groups highly expressed CD80, CD83 and CD86, indicating that both treatments efficiently generated mature αDC1s with the expected phenotype. Production of IL-12p70, IL-12p40 and IL-10 also increased upon αDC1 maturation in both groups. CTLs stimulated by either αDC1 group ("DC-CTLs") included numerous IFN-γ-secreting cells against T2 cells loaded with the corresponding multipeptides. Large numbers of IFN-γ-secreting cells were observed when human glioblastoma cell lines and primary cells were treated with multipeptide-pulsed DC-CTLs. Both multipeptide-pulsed DC-CTL groups exhibited cytotoxic activity of 40-60% against the U251 cell line and 60-80% against primary cells. Branched multipeptide from ERBB2, BIRC5 and CD99 stably bound with T2 cells, and its cytotoxicity toward target cells was similar to that of the multipeptide cocktail. Thus, branched multipeptides could be promising candidates for immunotherapeutic glioblastoma treatment., Competing Interests: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

The aim of this study was the immunological characterization of glioblastoma cells. Glioblastoma cell lines were cultured in serum and serum-free neurobasal (NBE) medium conditions. These cell lines were characterized by flow cytometry, reverse transcription-polymerase chain reaction (RT-PCR), western blot and natural killer (NK) cell-cytotoxicity assays. A previously described NK cell expansion method that uses K562 cells expressing interleukin (IL)-15 and 4-1 BB Ligand (BBL) (K562-mb15-41BBL) was used. RT-PCR and western blots for the expression of tumor-associated antigens (TAAs), were carried out in 32 glioblastoma and seven normal brain tissues. U87 and U343 tumor cell lines showed increased expression for major histocompatibility complex (MHC)-I and -II molecules. No significant differences in the levels of CD133, MHC class I/II, MHC class I-related chain A (MICA), MICB, UL16 binding protein 1-3 (ULBP 1-3) expression in these cell lines and in NK cell cytotoxicity were observed between serum and NBE conditions. Regardless of culture conditions, U87 and U343 cell lines were sensitive to expanded NK cells, with median cytotoxicities at 4:1 effector/target ratio of 43.2% and 46.5%, respectively. In RT-PCR, U343 and U87 showed the expression of most TAAs at a high ratio compared with U251. Western blots demonstrated positive expression for BIRC5, CD99 and ERBB2 in U251, U87 and U343 cell lines and tissues. These highly-expressed TAAs such as BIRC5, CD99 and ERBB2 in glioblastoma tissue could be the targets for immunotherapy. U87 and U343 cell lines could be useful for studying the efficacy of immunotherapy related to various TAAs and NK cell immunotherapy.

For elderly patients with glioblastoma multiforme (GBM), radiotherapy plus concomitant and adjuvant temozolomide has resulted in longer survival. We investigated patient performance status, treatment-related toxicity and overall survival (OS) following treatment. Twenty patients aged 70years or older with a newly diagnosed GBM were treated with radiotherapy (60Gy in 16 patients and 40Gy in four patients) plus concomitant and adjuvant temozolomide. We assessed age, the extent of tumor removal, and initial performance status as possible prognostic factors for OS and good performance status following treatment. The median OS was 11.8months (95% confidence interval [CI], 8.7-14.8). The median time for patients to reach an Eastern Cooperative Oncology Group (ECOG) performance status grade 2 was 3.0months (95% CI, 2.4-3.5), and the time to ECOG performance status grade 3 was 5.8months (95% CI, 1.6-9.9). World Health Organization grade III or grade IV toxicity was observed in four patients (20%), leucopenia and thrombocytopenia was noted in two patients, and major infection occurred in two patients. Univariate analysis showed a significantly longer OS (p=0.003) and a longer time with good performance status for gross total removal (GTR) (p=0.003). An initial good performance status was related to a good performance status during and after treatment (p=0.003). Based on multivariate analysis, GTR was significantly associated with a longer OS (hazard ratio [HR]=0.236; 95% CI, 0.060-0.922, p=0.038) and a good performance status (HR=0.124; 95% CI, 0.022-0.693, p=0.017). During and after treatment, elderly patients with GBM frequently exhibited an early deterioration of performance status. Therefore, in light of a rapidly fatal illness, elderly patients should be treated to preserve and respect their quality of life., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Anaplastic astrocytoma (AA) sometimes shows a rapid poor course like glioblastoma. In this study, we investigated the prognosis of AA with radiologic necrosis which is the representative radiologic finding of glioblastoma. From 1995 to 2010, we operated on 26 patients who were confirmed to have AA. The male:female ratio was 13:13, and the median age was 47.23 years. The mean follow-up period was 3 years. We analyzed the prognostic significance of radiologic necrosis with age, sex, KPS, tumour location, radiologic findings, extent of removal and radiation therapy oncology group recursive partitioning analysis (RTOG-RPA) classification. The median progression-free survival (PFS) was 0.5 (± 0.17) years and the median overall survival (OS) was 1.6 (± 0.40) years. In univariate analysis, the clinical variables of younger age (p = 0.030) and RTOG-RPA class III (p = 0.043) correlated with longer PFS, and KPS (p = 0.038), radiologic necrosis (p = 0.013) and the extent of removal (p = 0.041) correlated with OS. The median OS was 1.0 (± 0.21) year in AA with radiologic necrosis compared to AA without radiologic necrosis, which showed 2.1 (± 0.29) years median OS. On multivariate analysis, there was no statistically significant prognostic factor. However, Cox's regression model revealed that gross total removal was associated with a longer OS (hazard ratio = 0.136; 95% CI, 0.018 to 1.046; p = 0.055) compared to partial removal or biopsy. Gross total resection was associated with good prognosis, and AA with radiologic necrosis had poor prognosis like glioblastoma.

Purpose: Glioblastomas are the most malignant tumors of central nervous system neoplasms and are well known for their biological heterogeneity. Contrary to the putative hypothesis of purely glial differentiation in glioblastomas, they often demonstrate immunopositivity for neuronal markers. However, the significance of their neuronal marker expression is still controversial. To evaluate the prognostic implication of neuronal expression in glioblastoma, this study investigated the expression of neuronal markers in a large series of glioblastoma patients in terms of patient survival rate., Methods: Expression of synaptophysin, neurofilament protein, and NeuN was explored using immunohistochemistry in 88 cases of glioblastoma. Clinicopathological variables as well as patients' survival data were compared according to the immunopositivity of cases., Results: Sixty-one of the 88 tumors (69.3 %) were positive for at least one neuronal marker. Synaptophysin positivity was observed in 43 cases (48.9 %). Neurofilament protein and NeuN were positive in 38 (43.2 %) and 42 cases (47.7 %), respectively. There was no statistically significant difference in overall survival and progression-free survival in association with neuronal marker expression. However, gross total removal or combined radiotherapy and chemotherapy significantly prolonged survival (P=0.041 and 0.044). Cox's proportional hazard model revealed that NeuN expression was the independent prognostic factors in progression-free survival (P=0.012)., Conclusions: Although the correlation of neuronal marker expression and clinical outcome in glioblastoma is of considerable interest, the presented data support the limited prognostic value of neuronal marker expression in glioblastoma.

To obtain more representative biopsy specimens in glioblastoma, we performed multiple stereotactic biopsies of active tumor and necrosis. We investigated their pathologic differences of diagnosis and also examined the pathologic features that varied with 11C-methionine uptake on PET. From December 2009 to October 2010, we performed stereotactic biopsies in 12 patients with radiologically heterogeneous, ring-enhanced lesions. We biopsied the MR enhanced lesions for active tumor and the MR non-enhanced lesions for necrosis and analyzed differences of pathologic diagnoses between them. As correlating factors of the degree of 11C-methionine uptake (T/N ratio), the pathologic findings, including cell density, Ki‑67 LI, microvessel density, number of endothelial proliferations, the immunopositivity for L-amino acid transporter 1 (LAT1) were analyzed. The final diagnosis of each specimen was glio-blastoma. The diagnostic failure rate was 33.3% (4/12 patients) when we selected only active tumors and 40% (4/10 patients) when we selected necrotic lesions. The T/N ratio showed a statistical correlation with cell density depending on the degree of necrosis and LAT1 immunopositivity (P=0.002 and 0.032). LAT1 was localized in the tumor cells, vascular endothelium, and the vicinity of endothelial proliferation. Multiple stereotactic biopsies of active tumor and necrosis could provide the diagnostic yield in glioblastoma. The 11C-methionine uptake mostly reflected cell densities depending on the degree of necrosis.

This study was designed to determine the incidence and prognostic value of various populations of tumour-infiltrating T cells in glioblastomas. We also evaluated the difference in T-cell populations after conventional treatment. Sixty-seven patients with glioblastomas underwent surgery between 2003 and April 2009. Immunohistochemical staining was performed for CD3, CD4, CD8 and FoxP3, and the average number and percentage of positive cells were calculated. In eight patients, the average number of subpopulations was compared between the specimens obtained during the first and second operations. Age, gender, Karnofsky performance status, Radiation Therapy Oncology Group-recursive partitioning analysis (RTOG-RPA) classes, extent of removal, treatment modality, O-6-methylguanine-DNA methyltransferase (MGMT) methylation status and immunopositivity for CD4, CD8 and FoxP3 were analyzed as prognostic factors. There was an average of 12.8 ± 1.8 CD31 T cells, 1.5 ± 0.5 CD41 T cells, 6.8 ± 1.3 CD81 T cells and 0.6 ± 0.2 FoxP3 cells. The percentage of positive T-cell subpopulations was 89.6%, 22.4%, 77.6% and 34.3% for CD3, CD4, CD8 and FoxP3, respectively. In eight patients, there was no difference in the subpopulations between the first and second operations. The median progression-free survival was 7.0 months (95% CI, 5.2-8.9 months) and the overall survival was 14.8 months (95% CI, 11-18.7 months). Univariate analysis showed a statistically significant difference in progression-free survival for CD8 (p = 0.02) and overall survival for RTOG-RPA classes (p = 0.003), the extent of removal (p = 0.01) and MGMT promoter methylation status (p = 0.005). Based on multivariate analysis, RTOG-RPA classes were significantly associated with longer overall survival. The intratumoural immune response occurred frequently in glioblastomas and there was a consistent response, even after conventional treatment. There was a statistically significant difference in progression-free survival for CD81 T cells in immunologically privileged central nervous system.

Glioblastoma is one of the most frequent primary brain tumors and is characterized by aggressive clinical behavior and biologic heterogeneity. To evaluate the prognostic implication of cancer stem cell markers in glioblastoma, the expression of these markers was investigated in a large series of glioblastoma patients in relation to the survival rate. This series includes 88 cases of glioblastoma that were diagnosed at the Chonnam University Hwasun Hospital from 2004 to 2009. The expression of newly established stem cell markers (nestin, CD133 and CD15) was detected using immunohistochemical analysis. The presence of immunopositive tumor cells was evaluated and interpreted in comparison with the patients' survival data. The expression of nestin was high in 60 cases (68.2%). CD133 and CD15 were positive in 52 cases (59.1%) and 40 cases (45.5%), respectively. No statistically significant difference in patient survival according to stem cell marker expression was observed (P > 0.05). However, gross total resection or combined radiation therapy and chemotherapy significantly prolonged survival (P = 0.04 and P = 0.04). Cox's proportional hazards model showed that the gross total resection and combined radiation therapy and chemotherapy were independent prognostic factors. Although the correlation of stem cell marker expression with clinical outcome in glioma is of considerable interest, the data do not support their prognostic value in glioblastoma. Identification of the key cells in the glioblastoma population in the context of clinical outcomes will provide insight into the mechanism of brain tumorigenesis and will be of paramount importance in determining therapeutically appropriate targets., (© 2011 Japanese Society of Neuropathology.)

The aim of this study was to evaluate variations of O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation and protein expression after adjuvant treatment in glioblastoma patients. Sixteen patients with a glioblastoma underwent 34 microsurgeries including 18 re-operations. After surgery, patients underwent follow-up with radiotherapy and chemotherapy (temozolomide, ACNU and cisplatin) between 2000 and 2008. To investigate MGMT methylation and MGMT expression, methylation-specific PCR (MSP) and immunohistochemical staining (IHC) were performed. The methylation status of the MGMT promoter was altered in five (27.8%) of 18 re-operation specimens. In four specimens, the MGMT promoter was found to be methylated after primary surgery, but was found to be unmethylated on post-treatment samples. MGMT protein expression was altered in 15 (83.3%) of 18 cases. Fifteen specimens showed higher levels of protein expression as compared to previous samples and three samples demonstrated a similar expression pattern. After irradiation and exposure to steroid and temozolomide 6 and 24 h later, a methylated MGMT promoter and negative protein expression were seen in U343 glioblastoma cell lines which have methylated promoter and negative protein expression. Variations in MGMT promoter methylation and protein expression can occur after treatment. We suggest that changes of MGMT promoter methylation and protein expression might not be related to a direct effect of irradiation and exposure to steroid and temozolomide.

Objective: The aim of this study was to evaluate the correlation and prognostic significance of MGMT promoter methylation and protein expression in patients with glioblastoma., Methods: Eighty-three patients with glioblastoma underwent surgery followed by radiotherapy and temozolomide chemotherapy between October 2000 and June 2008. To investigate the correlation between MGMT methylation and MGMT expression, methylation-specific polymerase chain reaction (MSP) and immunohistochemical staining was performed. To analyze the correlation between MGMT methylation and MGMT expression according to location, biopsies were obtained from 37 different sites within the tumors in 12 patients. Age, sex, Karnofsky Performance Scale status, extent of removal, chemotherapeutic methods, and MGMT promoter methylation and protein expression were analyzed as prognostic factors., Results: The total median survival was 15.8 months (range, 12.6-19.1 months). The results of MSP were the same at various sites in 12 patients. A correlation between MSP and immunohistochemical staining was observed in 50% of the patients. In 73 patients, negative MGMT expression was detected in 70.5% of 44 patients with MGMT promoter methylation, and positive expression was observed in 55.2% of the 29 patients with unmethylated promoters. Multivariate analysis revealed that the extent of removal (P = 0.001) and the combination of MGMT promoter methylation and negative MGMT expression (median survival, 20.06 months; P = 0.006) were significantly associated with longer survival., Conclusion: We report the feasibility of using MSP combined with immunohistochemical staining as a prognostic factor. The results of the present study suggest that MGMT promoter methylation in combination with negative MGMT expression might be a good prognostic factor in patients with glioblastoma.

Object: Galectin-1 is highly expressed in motile cell lines. The authors investigated whether galectin-1 actually modulates the migration and invasion of human glioblastoma multiforme (GBM) cell lines, and whether its expression with respect to invasion and prognosis is attributable to certain glioma subgroups., Methods: In the human GBM cell lines U343MG-A, U87MG, and U87MG-10', the RNA differential display was evaluated using Genefishing technology. The results were validated by reverse transcription polymerase chain reaction and Northern blot analysis to detect possible genetic changes as the determining factors for the motility of the malignant glioma. The migration and invasion abilities were investigated in human GBM cell lines and galectin-1 transfectant using an in vitro brain slice invasion model and a simple scratch technique. The morphological and cytoskeletal (such as the development of actin and vimentin) changes were examined under light and confocal microscopy. Galectin-1 expression was assessed on immunohistochemical tests and Western blot analysis., Results: Endogenous galectin-1 expression in the human GBM cell lines was statistically correlated with migratory abilities and invasiveness. The U87-G-AS cells became more round than the U87MG cells and lacked lamellipodia. On immunohistochemical staining, galectin-1 expression was increased in higher-grade glioma subgroups (p = 0.027)., Conclusions: Diffuse gliomas demonstrated higher expression levels than pilocytic astrocytoma in the Western blot. Galectin-1 appears to modulate migration and invasion in human glioma cell lines and may play a role in tumor progression and invasiveness in human gliomas.

A 54-year-old man and a 63-year-old woman presented with glioblastoma manifesting as seizure and headache, respectively. Magnetic resonance imaging of the two patients revealed hypointense area on T(1)-weighted imaging, and hyperintense area on T(2)-weighted and diffusion-weighted imaging, with no enhancement after gadolinium administration. Both patients underwent conservative therapy under diagnoses of non-neoplastic cerebral lesion. Six months later, they suffered aggravated symptoms and new neurological deficits. Follow-up magnetic resonance imaging revealed hypointense area on diffusion-weighted imaging and ring enhancement on T(1)-weighted imaging with gadolinium at the site of the previously detected lesions. The tumors showed growth pattern of superficial origin. The large enhanced masses were totally removed through craniotomy under neuronavigator guidance. The histological diagnoses were glioblastoma. Glioblastoma may mimic non-neoplastic conditions on neuroimaging in the early stages. Close follow up of such patients is essential.