Jun Ichi Kuratsu

Possible involvement of the M2 anti-inflammatory macrophage phenotype in growth of human gliomas

Within tumours, many non‐neoplastic cells such as fibroblasts, endothelial cells, and macrophages assist tumour growth by producing various growth factors and pro‐angiogenic cytokines. Various tumour‐derived molecules drive tumour‐associated macrophages towards an anti‐inflammatory phenotype (M2) and thus promoting tumour growth. Here we investigated microglia/macrophage differentiation in glioma tissues by means of immunostaining of paraffin‐embedded glioma samples. The number of microglia/macrophages with positive staining for CD163 and CD204, which are believed to be markers for M2 macrophages, was correlated with the histological grade of the gliomas. The ratio of M2 macrophages in the tumour‐associated microglia/macrophages was also associated with the histological grade. Culture supernatant from the glioma cell line can stimulate macrophages to develop into the M2 phenotype in vitro. Macrophage colony‐stimulating factor (M‐CSF), which strongly induces M2 polarization of macrophages, was significantly correlated with histological malignancy and with the proportion of M2 microglia/macrophages in vivo. In addition, the proportion of M2 microglia/macrophages and M‐CSF expression in tumour cells correlated well with proliferation of glioblastoma cells. These results suggest that tumour‐derived M‐CSF induces a shift of microglia/macrophages towards the M2 phenotype, which influences tumour growth. Evaluation of the proportion of M2 microglia/macrophages and M‐CSF expression in tumour tissue would be useful for assessment of microglia/macrophage proliferative activity and the prognosis of patients with gliomas. Copyright

Expression of tissue factor correlates with grade of malignancy in human glioma

Tissue factor (TF), a cell surface receptor of factor VII/VIIa, was initially recognized as an initiator of the extrinsic coagulation pathway. TF has recently been found to be expressed highly in certain types of malignant tumors. In addition, TF belongs to the interferon receptor family and is one of the immediate early genes, suggesting that TF may participate in the regulation of cell growth. However, the correlation between the expression of TF and cell growth is still unclear.

Grading Astrocytic Tumors by Using Apparent Diffusion Coefficient Parameters: Superiority of a One- versus Two-Parameter Pilot Method

PURPOSE To assess the utility of both minimum apparent diffusion coefficients (ADCs) and ADC difference values for grading astrocytic tumors at magnetic resonance imaging. MATERIALS AND METHODS The hospitals institutional review board approved this retrospective study and waived informed consent. Fifty patients (23 male patients, 27 female patients; median age, 53 years) with newly diagnosed astrocytic tumors were evaluated. Two observers blinded to clinical information independently measured the ADCs by manually placing three to five regions of interest (40-60 mm(2)) within the solid tumor either with or without contrast material-enhanced components and calculated the average ADC. Minimum and maximum ADCs were selected, and the difference between them was recorded as the ADC difference value. These ADC values were used as the parameters for tumor grading and were compared by using the Kruskal-Wallis test and receiver operating characteristic (ROC) curve analysis. RESULTS According to ROC analyses for distinguishing tumor grade, minimum ADCs showed the largest areas under the ROC curve. Minimum ADCs optimally helped distinguish grade 1 from higher-grade tumors at a cutoff value of 1.47 x 10(-3) mm(2)/sec and grade 4 from lower-grade tumors at a cutoff value of 1.01 x 10(-3) mm(2)/sec (P < .001 for both). ADC difference values helped distinguish grade 2 from grade 3 tumors at a cutoff value of 0.31 x 10(-3) mm(2)/sec (P < .001). When tumors were graded by using the combined minimum ADC and ADC difference cutoff values mentioned above (the two-parameter method), the following positive predictive values were obtained: grade 1 tumors, 73% (eight of 11); grade 2 tumors, 100% (five of five); grade 3 tumors, 67% (eight of 12); and grade 4 tumors, 91% (20 of 22). CONCLUSION Using a combination of minimum ADCs and ADC difference values (the two-parameter method) facilitates the accurate grading of astrocytic tumors.

Functional anatomy of the basal ganglia in X-linked recessive dystonia-parkinsonism.

Dystonia is a neurological syndrome characterized by sustained muscle contractions that produce repetitive twisting movements or abnormal postures. X‐linked recessive dystonia parkinsonism (XDP; DYT3; Lubag) is an adult‐onset disorder that manifests severe and progressive dystonia with a high frequency of generalization. In search for the anatomical basis for dystonia, we performed postmortem analyses of the functional anatomy of the basal ganglia based on the striatal compartments (ie, the striosomes and the matrix compartment) in XDP. Here, we provide anatomopathological evidence that, in the XDP neostriatum, the matrix compartment is relatively spared in a unique fashion, whereas the striosomes are severely depleted. We also document that there is a differential loss of striatal neuron subclasses in XDP. In view of the three‐pathway basal ganglia model, we postulate that the disproportionate involvement of neostriatal compartments and their efferent projections may underlie the manifestation of dystonia in patients with XDP. This study is the first to our knowledge to show specific basal ganglia pathology that could explain the genesis of dystonia in human heredodegenerative movement disorders, suggesting that dystonia may result from an imbalance in the activity between the striosomal and matrix‐based pathways. Ann Neurol 2005

Prognostic Value of Perfusion MR Imaging of High-Grade Astrocytomas: Long-Term Follow-Up Study

BACKGROUND AND PURPOSE: Although the prognostic value of perfusion MR imaging in various gliomas has been investigated, that in high-grade astrocytomas alone has not been fully evaluated. The purpose of this study was to evaluate retrospectively whether the tumor maximum relative cerebral blood volume (rCBV) on pretreatment perfusion MR imaging is of prognostic value in patients with high-grade astrocytoma. MATERIALS AND METHODS: Between January 1999 and December 2002, 49 patients (30 men, 19 women; age range, 23–76 years) with supratentorial high-grade astrocytoma underwent MR imaging before the inception of treatment. The patient age, sex, symptom duration, neurologic function, mental status, Karnofsky Performance Scale, extent of surgery, histopathologic diagnosis, tumor component enhancement, and maximum rCBV were assessed to identify factors affecting survival. Kaplan-Meier survival curves, the logrank test, and the multivariate Cox proportional hazards model were used to evaluate prognostic factors. RESULTS: The maximum rCBV was significantly higher in the 31 patients with glioblastoma multiforme than in the 18 with anaplastic astrocytoma (P < .03). The 2-year overall survival rate was 67% for 27 patients with a low (≤2.3) and 9% for 22 patients with a high (>2.3) maximum rCBV value (P < .001). Independent important prognostic factors were the histologic diagnosis (hazard ratio = 9.707; 95% confidence interval (CI), 3.163–29.788), maximum rCBV (4.739; 95% CI, 1.950–11.518), extent of surgery (2.692; 95% CI, 1.196–6.061), and sex (2.632; 95% CI, 1.153–6.010). CONCLUSION: The maximum rCBV at pretreatment perfusion MR imaging is a useful clinical prognostic biomarker for survival in patients with high-grade astrocytoma.

Natural history of elderly patients with asymptomatic meningiomas

OBJECTIVE For the treatment of elderly patients with asymptomatic meningiomas, it is important to determine their natural history. Based on results of follow up examinations, the natural history of such patients was clarified and prognostic factors concerning the potential of tumour growth in the aged were identified. METHODS The clinical records and imaging studies of 40 elderly (over 70 years) patients with asymptomatic meningiomas were analysed. The patients were followed up with repeated imaging studies, and changes in tumour size, clinical signs, and outcomes were evaluated. RESULTS There were 32 women and eight men with a mean age of 76.1 years. The mean follow up period was 38.4 months, ranging from 6 to 97 months. Six patients died during the follow up period from disorders other than the tumours, and one patient died as a result of the tumour. Twenty six patients (mean follow up period 41.8 months, range 10–97 months) showed no tumour growth. Fourteen patients showed tumour growth (mean follow up period 32.1 months, range 6–88 months). Five (four men and one woman) of these patients became symptomatic. Based on imaging analysis (1) calcification of the tumour was associated with no tumour growth (p=0.036), and (2) the tumour size at the initial diagnosis was related to subsequent tumour growth (p=0.016). Other possible factors related to tumour growth included sex and hyperintensity on MRI T2 weighted images. CONCLUSION In elderly patients with asymptomatic meningiomas, careful clinical follow up with imaging studies is important. The imaging features mentioned may contribute to prediction of tumour growth.

Are nonfunctioning pituitary adenomas extending into the cavernous sinus aggressive and/or invasive?

OBJECTIVEWe studied nonfunctioning pituitary adenomas extending to the cavernous sinus to gain insight into the discrepancy between their histologically benign nature and frequent extension into the cavernous sinus. METHODSWe studied 10 patients with nonfunctioning pituitary adenomas that completely encircled the cavernous carotid artery (extension group). All 10 patients underwent surgery to remove intrasellar and/or suprasellar parts of the adenomas. Ten patients with nonfunctioning pituitary adenomas without cavernous sinus extension comprised the control group. Tumor size follow-up data were obtained by magnetic resonance imaging. Immunostaining was performed for Ki-67, cathepsin B, and matrix metalloprotainase-9. To assess the wall thickness, 10 cavernous sinuses were removed from the cranial base of adult cadavers, and the walls were examined histologically. RESULTSMagnetic resonance imaging demonstrated no remarkable growth in most of the patients during the follow-up period (mean, 65.8 mo). There was no statistical difference in Ki-67, cathepsin B, and matrix metalloprotainase-9 immunostaining between the extension group and the control group. The cadaver study demonstrated that the medial wall was significantly thinner than the superior and the lateral walls (P < 0.0005). We found small defects in the capsule histologically in 3 of 30 sections. CONCLUSIONOur results indicate that most of nonfunctioning pituitary adenomas extending into the cavernous sinus are neither aggressive nor invasive. The high incidence of cavernous sinus extension of benign adenomas may be caused by the weakness of the medial wall of the cavernous sinus.

Sox11 Prevents Tumorigenesis of Glioma-Initiating Cells by Inducing Neuronal Differentiation

Recent findings have shown that malignant tumors contain cancer-initiating cells (CIC), which self-renew and are tumorigenic. However, CICs have not been characterized properly due to lack of specific markers. We recently established a mouse glioma cell line, NSCL61, by overexpressing an oncogenic HRas(L61) in p53-deficient neural stem cells. Using limiting dilution assays, we show that only 2 of 24 NSCL61 clones retained their tumorigenicity in vivo, although the others also expressed oncogenic HRas(L61) and could proliferate in culture. A comparison of the gene expression profiles of tumorigenic and nontumorigenic clones showed that the tumorigenic clones had lost Sox11 expression. We show that overexpression of sox11 prevented tumorigenesis of NSCL61s by inducing their neuronal differentiation accompanied with decreased levels of plagl1. We also show that overexpression of plagl1 abolished neuronal commitment of nontumorigenic cells and induced them to become tumorigenic. Moreover, we show that human glioma-initiating cells lost sox11 expression, and overexpression of sox11 prevented their tumorigenesis in vivo. Together with the clinical evidence showing that downregulation of sox11 mRNA correlates with a significant decrease in survival, these findings suggest that Sox11 prevents gliomagenesis by blocking the expression of oncogenic plagl1.

Identification of the cis‐acting region in the NF2 gene promoter as a potential target for mutation and methylation‐dependent silencing in schwannoma

Although mutational inactivation and allelic loss in the NF2 gene appear to be causal events in the majority of vestibular schwannomas, involvement of another potentially important mechanism, transcriptional inactivation, has not been investigated.

Essential role of the Hedgehog signaling pathway in human glioma‐initiating cells

Recent findings have demonstrated that malignant tumors, including glioblastoma multiforme, contain cancer‐initiating cells (also known as cancer stem cells), which self‐renew and are malignant, with features of tissue‐specific stem cells. As these cells are resistant to irradiation and anti‐cancer drugs, it is important to characterize them and find targeting therapies. In this study, we established two primary human glioma cell lines from anaplastic oligodendroglioma and glioblastoma multiforme. These lines were enriched in glioma‐initiating cells, as just 10 cells formed malignant glioma when injected into mouse brain. We used these cell lines to examine the roles of the Notch, Hedgehog and Wnt signaling pathways, which are involved in stem‐cell maintenance and tumorigenesis, to determine which of these pathways are crucial to glioma‐initiating cells and their regulation. Here we show that the Hedgehog pathway is indispensable for glioma‐initiating cell proliferation and tumorigenesis; the Hedgehog signaling inhibitors prevented glioma‐initiating cell proliferation, while signaling inhibitors for Notch or Wnt did not. Overexpression of Gli2ΔC, a C‐terminal‐truncated form of Gli2 that antagonizes Gli transcription factor functions, blocked glioma‐initiating cell proliferation in culture and tumorigenesis in vivo. Knockdown of the Gli downstream factor Cdc2 also prevented glioma‐initiating cell proliferation. Taken together, these results show that the Hedgehog→ Gli→ Cdc2 signaling cascade plays a role in the proliferation and malignancy of glioma‐initiating cells. (Cancer Sci 2011; 102: 1306–1312)