Basophilic invasion in the neurohypophysis is increased in patients with Alzheimer's disease.

PURPOSE: The prevalence of basophilic invasion (BI) and degenerative changes in the neurohypophysis of humans with neurodegenerative disease is not established. MATERIALS AND METHODS: We evaluated 122 pituitary glands reviewed at autopsy including 45 with Alzheimer's disease (AD) Braak and Braak stage V or VI, 18 with Lewy body disease (LBD), and 59 age-matched controls for BI. In addition, pituitary glands from 51 patients including 25 patients with AD and 18 aged-matched controls were studied with a periodic acid Schiff (PAS) stain and immunohistochemistry with a polyclonal antibody to nestin. Samples were graded as negative (0) or positive (1). RESULTS: BI was seen in 35 of 45 patients with AD (0.78 ± 0.06 mean and SE: 78%) and was significantly higher than 30 of 59 controls (0.51 ± 0.07; 51%) (p = 0.0236). BI was seen in 7 of 18 patients with LBD (0.39 ± 0.12; 39%) compared to controls (p = 0.387). BI was also significantly higher in AD compared to LBD (p = 0.0001). Nestin immunoreactivity was detected in the neurohypophysis of all patients. Definite nestin was not found in BI but was seen in Herring body-like structures, in pituicytes and axons. Phospho-τ-immunoreactive Herring bodies were seen in 65% with AD but phospho-τ-immunoreactive neurofibrillary tangles were not found. CONCLUSION: BI is increased in AD compared to controls or LBD but not associated with nestin immunoreactivity. The significance and role of BI as a marker for AD warrants additional study.

Imaging and clinicopathologic features of myxoid meningiomas.

AIMS: Due to their rarity, the natural history and imaging of myxoid meningiomas are not completely characterized. We analyzed clinical, imaging, and pathologic features of myxoid meningioma seen neurosurgically or in consultation between 1999 and 2018. MATERIALS AND METHODS: Archival material was searched for meningiomas designated "myxoid meningioma" at Vanderbilt University School of Medicine (1997 - 2004) and the University of Rochester School of Medicine and Dentistry (1994 - 2018). RESULTS: Our cases were predominantly in females and presented with a slow progression of symptoms. Each tumor was in the hemispheres. Magnetic resonance imaging (MRI) found most were hyperintense on T2-weighted images. Each meningioma had foci of limited meningothelial amongst extensive myxoid histology with Alcian-blue-staining stroma and EMA-immunoreactive cells. CONCLUSION: Myxoid meningiomas present with atypical imaging and histologic characteristics but are not truly metaplastic, i.e., are not differentiated to a different cell type.

Clinicopathologic features of incidental meningiomas: A review of the literature and the University of Rochester autopsy experience.

OBJECTIVE: Features of incidental meningiomas, found at autopsy, have not been extensively reported and may offer insight into their biology and management. DESIGN: Review of the literature on unsuspected incidental antemortem and postmortem meningiomas and those from autopsies, at the University of Rochester from 2005 to 2016. RESULTS: At autopsy, incidental meningiomas were usually found in 2 - 3% of cases. Incidental meningiomas found by neuroimaging were more commonly seen over the convexities, although our findings suggest that parasellar meningiomas are common. They are and are more commonly in males, WHO grade I, and fibrous or meningothelial, but our findings suggest psammomatous meningiomas are over-represented. CONCLUSION: Incidental meningiomas are a relatively common unrecognized tumor. They are more likely to be in males, WHO grade I, parasellar, and with calcification.
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The preliminary radiogenomics association between MR perfusion imaging parameters and genomic biomarkers, and their predictive performance of overall survival in patients with glioblastoma.

The radiogenomics association of neovascularization is important for overall survival (OS) in glioblastoma patients and remains unclear. The purpose of this study is to assess the association between MR perfusion imaging derived parameters and genomic biomarkers of glioblastoma, and to evaluate their prognostic value. This retrospective study enrolled 41 patients with newly diagnosed glioblastoma. The mean and maximal relative cerebral blood volume (rCBV) ratio (rCBVmean and rCBVmax), derived from MR perfusion weighted imaging, of the enhancing tumor, as well as maximal rCBV ratio of peri-enhancing tumor area (rCBVperi-tumor) were measured. The ki-67 labeling index, mammalian target of rapamycin (mTOR) activation, epidermal growth factor receptor (EGFR) amplification, isocitrate dehydrogenase (IDH) mutation and TP53 were assessed. There was a significant correlation between rCBVmax and mTOR based on Pearson's correlations with Benjamini-Hochberg adjustment for controlling false discovery rate, p = 0.047. The rCBVperi-tumor showed significant correlation with mTOR (p = 0.0183) after adjustment of gender and EGFR status. The mean rCBVperi-tumor value of the patients with OS shorter than 14 months was significantly higher than patients with OS longer than 14 months, p = 0.002. The rCBVperi-tumor and age were the two strongest predictors of OS (hazard ratio = 1.29 and 1.063 respectively) by Cox regression analysis. This study showed that hemodynamic abnormalities of glioblastoma were associated with genomics activation status of mTOR-EGFR pathway, however, the radiogenomics associations are different in enhancing and peri-enhancing area of glioblastoma. The rCBVperi-tumor has better prognostic value than genomic biomarkers alone.

Cucurbitacin I blocks cerebrospinal fluid and platelet derived growth factor-BB stimulation of leptomeningeal and meningioma DNA synthesis.

BACKGROUND: Currently, there are no consistently effective chemotherapies for recurrent and inoperable meningiomas. Recently, cucurbitacin I (JSI-124), a naturally occurring tetracyclic triterpenoid compound used as folk medicines has been found to have cytoxic and anti-proliferative properties in several malignancies thru inhibition of activator of transcription (STAT3) activation. Previously, we have found STAT3 to be activated in meningiomas, particularly higher grade tumors. METHODS: Primary leptomeningeal cultures were established from 17, 20 and 22 week human fetuses and meningioma cell cultures were established from 6 World Health Organization (WHO) grade I or II meningiomas. Cells were treated with cerebrospinal fluid from patients without neurologic disease. The effects of cucurbitacin I on cerebrospinal fluid stimulation of meningioma cell DNA synthesis phosphorylation/activation of JAK1, STAT3, pMEK1/2, p44/42MAPK, Akt, mTOR, Rb and caspase 3 activation were analyzed in human leptomeningeal and meningioma cells. RESULTS: Cerebrospinal fluid significantly stimulated DNA synthesis in leptomeningeal cells. Co-administration of cucurbitacin I (250 nM) produces a significant blockade of this effect. Cucurbitacin I alone also produced a significant reduction in basal DNA synthesis. In grade I and II meningiomas, cerebrospinal fluid also significantly stimulated DNA synthesis. Co-administration of cucurbitacin I (250 nM) blocked this effect.In the leptomeningeal cultures, cerebrospinal fluid stimulated STAT3 phosphorylation but not p44/42MAPK, Akt or mTOR. Cucurbitacin I had no effect on basal STAT3 phosphorylation but co-administration with cerebrospinal fluid blocked cerebrospinal fluid stimulation of STAT3 phosphorylation in each. In the grade I meningiomas, cerebrospinal fluid stimulated phosphorylation of STAT3 and decreased MEK1/2 and cucurbitacin I had no effect on basal STAT3, p44/42MAPK, Akt, JAK1, mTOR, or Rb phosphorylation. In the grade II meningiomas, cerebrospinal fluid stimulated STAT3 phosphorylation in all and reduced phosphorylation of MEK1/2 in all and p44/42MAPK in one. Cucurbitacin I had no effect on basal phosphorylation of STAT3 but reduced phorphorylated p44/42 MAPK in 2 grade II meningioma cells lines. CONCLUSIONS: These studies raise the possibility that cucurbitacin I might have value as an adjunct chemotherapy. Additional studies are warranted to evaluate the effects of cucurbitacin I on meningiomas in vivo.

Carotid Intimal Sarcoma Presenting as Large Vessel Occlusion and Diagnosed by Embolus Histopathology: Case Report.

Objective: The objective of this study was to present the clinical, histopathologic, and radiographic findings of a unique case of intimal sarcoma (IS) embolus presenting as a large vessel occlusion causing an ischemic stroke without a detectable primary tumor site. Methods: Extensive examinations, multimodal imaging, laboratory testing, and histopathologic analysis were used in evaluation. Results: We report the case of a patient who presented with acute embolic ischemic stroke and was found to have IS based on a histopathologic evaluation of his embolectomy specimen. Subsequent comprehensive imaging studies failed to detect a primary tumor site. Multidisciplinary interventions including a course of radiotherapy were performed. The patient died of recurrent multifocal strokes 92 days after diagnosis. Discussion: Meticulous histopathologic analysis should be conducted on cerebral embolectomy specimens. Histopathology may be useful in diagnosing IS.

Clinical utility of whole-genome DNA methylation profiling as a primary molecular diagnostic assay for central nervous system tumors-A prospective study and guidelines for clinical testing.

Background: Central nervous system (CNS) cancer is the 10th leading cause of cancer-associated deaths for adults, but the leading cause in pediatric patients and young adults. The variety and complexity of histologic subtypes can lead to diagnostic errors. DNA methylation is an epigenetic modification that provides a tumor type-specific signature that can be used for diagnosis. Methods: We performed a prospective study using DNA methylation analysis as a primary diagnostic method for 1921 brain tumors. All tumors received a pathology diagnosis and profiling by whole genome DNA methylation, followed by next-generation DNA and RNA sequencing. Results were stratified by concordance between DNA methylation and histopathology, establishing diagnostic utility. Results: Of the 1602 cases with a World Health Organization histologic diagnosis, DNA methylation identified a diagnostic mismatch in 225 cases (14%), 78 cases (5%) did not classify with any class, and in an additional 110 (7%) cases DNA methylation confirmed the diagnosis and provided prognostic information. Of 319 cases carrying 195 different descriptive histologic diagnoses, DNA methylation provided a definitive diagnosis in 273 (86%) cases, separated them into 55 methylation classes, and changed the grading in 58 (18%) cases. Conclusions: DNA methylation analysis is a robust method to diagnose primary CNS tumors, improving diagnostic accuracy, decreasing diagnostic errors and inconclusive diagnoses, and providing prognostic subclassification. This study provides a framework for inclusion of DNA methylation profiling as a primary molecular diagnostic test into professional guidelines for CNS tumors. The benefits include increased diagnostic accuracy, improved patient management, and refinements in clinical trial design.

Mycoplasmal panencephalitis: a neuropathologic documentation.

Mycoplasmas, particularly Mycoplasma pneumoniae, have been implicated as causative agents in a large variety of central nervous system diseases, especially acute childhood encephalitis. Postulated pathomechanisms for mycoplasma-mediated neurological disease have included: direct infection, autoimmunity, and vascular occlusion. Neuropathologic data are meager and are reviewed. We report a 3-year-old boy, who developed signs and symptoms of encephalitis 7 days after the onset of fever with cough and death 5 days later. At autopsy, he displayed diffuse vasogenic edema and perivascular to infiltrative inflammatory cells, the latter most prominent in gray matter of brainstem and amygdala. The predominant cell was the CD68-positive macrophage, followed by the T-lymphocyte. Cells immunolabeled with a polyclonal antibody to M. pneumoniae included perivascular to parenchymal macrophages/microglia, occasional oligodendrocytes, and neurons, particularly in brainstem. Affected neurons varied from morphologically normal to profoundly degenerate and necrotic. Ultrastructural study of the inferior olive confirmed the presence of 260-600 nm cell-wall-free microorganisms, consistent with mycoplasma, in perivascular cells and neurons. Foci of acute disseminated encephalomyelitis also were rarely identified. This case report confirms the postulated role of direct infection of brain by mycoplasma in acute childhood encephalitis, but also reveals a virus-like infection of central neurons. The pathogenesis of acute childhood encephalitis due to mycoplasma seems to be multifactorial.

Cerebrospinal fluid stimulates leptomeningeal and meningioma cell proliferation and activation of STAT3.

The role of cerebrospinal fluid (CSF) in the pathogenesis of meningiomas is unknown. Cell cultures from three human leptomeninges, five WHO grade I and seven grade II meningiomas were treated with remnant CSF from 22 patients with no central nervous system disease and normal cell indices. Cells were evaluated by CyQUANT for DNA synthesis/cell proliferation and by western blots for phosphorylation/activation of growth regulatory pathways activated in meningiomas including JAK1-STAT3, MEK1-p44/42MAPK, Akt-mTOR and Rb. Analysis of Caspase 3 activation and survivin was also performed. Finally, the effects of PDGF neutralizing antibody and cucurbitacin, a STAT3 inhibitor on CSF stimulation were tested. Compared to controls and the mitogen PDGF-BB, various CSF samples significantly stimulated DNA synthesis/cell proliferation in 20 and 22 week leptomeningeal cultures and all of the grade I and II meningioma cells tested. Collectively CSF samples, from multiple different patients, stimulated DNA synthesis in tests of 23 of 32 grade I and 18 of 28 grade II meningioma cells. CSF stimulated phosphorylation/activation of STAT3 and reduced p44/42 MAPK in the leptomeningeal, all three grade I and 1 of three grade II meningioma cells. CSF did not affect Caspase 3 activity or survivin levels. PDGF neutralizing antibody had no effect on CSF stimulation but cucurbitacin blocked PDGF and CSF stimulation. While there are limitations to the CSF available since they were not from "normal" volunteers, the studies suggest that, in some settings, CSF is potentially mitogenic to leptomeningeal and meningioma cells and may act, in part, via activation of STAT3.

Metastases to Meningiomas: A Comprehensive Literature Review Including Mediating Proteins.

Approximately 5-15% of solid tumors metastasizing to the central nervous system metastasize to the leptomeninges. Less common, is metastasis to leptomeningeal meningiomas. These are primarily carcinomas of the breast and lung. Awareness of this phenomenon is critical to the evaluation of meningiomas, especially since the metastases may be the first indication of an occult tumor elsewhere in the body. Lack of clear demarcation between the metastasis and meningioma parenchyma, as well as histological features similar to the meningioma, may hinder recognition. The mechanisms underlying metastases anchoring and spread along the leptomeninges are not established. However, several cell adhesion molecules are thought to contribute to this phenomenon. E cadherin is a cell adhesion molecule present in meningioma cells. Binding to endothelium by adhesion molecules such as ICAM, B1 integrin, P-selectin, PECAM-1, CXCL12 and SDF-1 have also been proposed as part of the mechanisms underlying breast carcinoma metastases. In addition, the leptomeninges and meningiomas express mesothelin that acts as an anchoring protein coupling with mucin-16. Consequently, metastatic tumor cell mucin and mesothelin may also facilitate the anchoring of metastases to meningiomas.

Lopinavir inhibits meningioma cell proliferation by Akt independent mechanism.

Recent studies suggest that HIV-1 protease inhibitors may have anti-neoplastic effects on some malignancies. The anti-neoplastic effects of lopinavir have not been established or studied in brain tumors. Primary cultures of three fetal leptomeninges and 18 meningiomas were treated with lopinavir alone or with PDGF-BB. DNA synthesis was assessed by CyQUANT. Lopinavir effects on basal and PDGF-stimulated phosphorylation of the Akt-mTOR, MEK1/2-MAPK and STAT3 pathways, phosphorylation of Rb, Caspase 3 activation and reductions in survivin were assessed by Western blots. Lopinavir produced a significant reduction in PDGF-BB stimulation of DNA synthesis in a leptomeningeal culture (P = 0.0013) and 1 of 6 WHO grade I and 1 of 4 grade II meningiomas at 24 h and in 3 of 6 WHO grade I, 4 of 4 grade II and 1 of 1 grade III cell cultures (P = 0.0001) at 72 h. Lopinavir reduced PDGF-BB stimulation of phosphorylation/activation of MAPK in the 22 week fetal leptomeningeal cell cultures and in cells from 1 grade I meningioma at 24 h, but in none of 4 grade I and 5 grade II meningiomas at 6 h. Lopinavir had no notable effect on basal or PDGF-stimulated p-mTOR, p-MEK1/2, or p-STAT3, activation of Caspase 3 or survivin levels. Lopinavir treatment for 24 h had no effect on basal Rb phosphorylation but reduced Rb phosphorylation in all four meningioma cultures. These studies suggest that lopinavir may inhibit meningioma growth, and does so in part by cell cycle arrest. Additional evaluation of lopinavir as a potential adjunct chemotherapy is warranted.

Analysis of transforming growth factor ß receptor expression and signaling in higher grade meningiomas.

TGF-ß receptors (TGF-ßRs) inhibit growth of many cell types. Loss of TGF-ßRs or its signaling components have been found in several human malignancies. The expression and the role of TGF-ßRs in regulating anaplastic meningioma growth has not been studied. Real time PCR found TGF-ß RIII expression significantly lower in five grade III compared to eight grade I and eight grade II tumors (P = 0.0481). By western blot analysis, TGF-ßRI was detected in the four fetal and adult leptomeninges, all 18 grade I, 14 grade II and six grade III meningiomas. TGF-ßRII was detected in none of the leptomeninges, 55% of grade I, 71% of grade II and weak to negative in five of six the grade III meningiomas analyzed. TGF-ßRIII immunoreactivity was not detected in the fetal meninges but was detected in 94% of grade I, 70% of grade II and 67% grade III tumors. Phospho-SMAD 3 and Smad 7 were detected in nearly all tumors. TGF-ß1 had no effect on PDGF-BB stimulation of DNA synthesis in six of seven WHO grade II and the grade III cells. It produced an increase in phosphorylation of SMAD 3 and p38MAPK in two of four and p44/42MAPK in three of four grade II cells showing no change in DNA synthesis after treatment. Thus, only attenuated TGF-ßRIII expression and TGFB growth inhibition may occur in select higher grade meningiomas. Nonetheless, restoring TGF-ß inhibition of meningioma cell proliferation may be an important objective in the design of new chemotherapies for these tumors.

Evaluation of fluid channels in the human dura and superior sagittal sinus in older patients.

AIM: Recent studies suggest the leptomeninges may have a lymphatic drainage system connecting the subarachnoid space with dorsal cervical lymph nodes. The distribution and histologic features of any dural "lymphatics" has not been established or extensively studied. MATERIAL AND METHODS: Duras from 113 patients were evaluated including 96 formalin-fixed dural samples (mean age 62 years) collected from 2010 to 2015. An additional 17 samples were collected from Alzheimer's disease (AD) patients (mean age 81) autopsied between 1995 and 1997. Two, 2 cm length coronal sections were taken from mid-convexity dura, parallel to the middle meningeal artery, 3-5 cm below and perpendicular to the superior sagittal sinus (SSS). Sections of twenty-two cases were also taken of the SSS and peri-SSS dura. To screen for possible lymphatics, 52 dural and 22 SSS samples from these cases were evaluated with CD31 and podoplanin (D240) immunohistochemistry. RESULTS: Numerous unlined microscopic channels were found in 101 of 113 (89 %). In non-AD duras, 86 of 92 (93 %) had numerous channels. Duras with AD had significantly less channels i.e. 15 of 21(71 %, P = 0.048). None of the channels had lymphocytes, or neutrophils in their lumena. In the superior sagittal sinus, 9 of 9 non-AD and 12/13 AD SSS duras had fluid channels. Congo red stains revealed no amyloid-like material in the AD duras. Immunohistochemically, CD31 was not found in fluid channels but was in endothelium in 36 of 36 non-AD duras and in most blood vessels including 16 of 16 AD patients. Seven of 36 (19 %) with non-AD and 1 of 16 (6%) with AD had podoplanin in thin walled vessels suggestive of lymphatics but none showed staining in fluid channels. CONCLUSIONS: Unlined fluid channels are present in the dura but not clearly lymphatic.

Brain Histopathology of Adult Decedents After Extracorporeal Membrane Oxygenation.

OBJECTIVE: To test the hypothesis that brain injury is more common and varied in patients receiving extracorporeal membrane oxygenation (ECMO) than radiographically observed, we described neuropathology findings of ECMO decedents and associated clinical factors from 3 institutions. METHODS: We conducted a retrospective multicenter observational study of brain autopsies from adult ECMO recipients. Pathology findings were examined for correlation with demographics, clinical data, ECMO characteristics, and outcomes. RESULTS: Forty-three decedents (n = 13 female, median age 47 years) received autopsies after undergoing ECMO for acute respiratory distress syndrome (n = 14), cardiogenic shock (n = 14), and cardiac arrest (n = 15). Median duration of ECMO was 140 hours, most decedents (n = 40) received anticoagulants; 60% (n = 26) underwent venoarterial ECMO, and 40% (n = 17) underwent venovenous ECMO. Neuropathology was found in 35 decedents (81%), including microhemorrhages (37%), macrohemorrhages (35%), infarctions (47%), and hypoxic-ischemic brain injury (n = 17, 40%). Most pathology occurred in frontal neocortices (n = 43 occurrences), basal ganglia (n = 33), and cerebellum (n = 26). Decedents with hemorrhage were older (median age 57 vs 38 years, p = 0.01); those with hypoxic brain injury had higher Sequential Organ Failure Assessment scores (8.0 vs 2.0, p = 0.04); and those with infarction had lower peak Paco2 (53 vs 61 mm Hg, p = 0.04). Six of 9 patients with normal neuroimaging results were found to have pathology on autopsy. The majority underwent withdrawal of life-sustaining therapy (n = 32, 74%), and 2 of 8 patients with normal brain autopsy underwent withdrawal of life-sustaining therapy for suspected neurologic injury. CONCLUSION: Neuropathological findings after ECMO are common, varied, and associated with various clinical factors. Further study on underlying mechanisms is warranted and may guide ECMO management.

Primary spinal cord glioma: a Surveillance, Epidemiology, and End Results database study.

To characterize the overall survival (OS) and cause specific survival (CSS), and variables affecting outcome, in patients with primary spinal cord astrocytoma (SCA) and ependymoma (SCE). About 664 patients with SCA and 1,057 patients with SCE were analyzed using the Surveillance, Epidemiology, and End Results database. For grade 1, 2, 3 and 4 SCA, the 5-year OS was 82, 70, 28 and 14%; the 5-year CSS was 89, 77, 36 and 20%. For SCA, lower grade, younger age, and undergoing resection significantly improved OS and CSS; treatment without radiotherapy was favorable for CSS. Smaller tumor size also improved survival. For grade 1, 2, and 3 SCE, the 5-year OS was 92, 97 and 58%; the 5-year CSS was 100, 98 and 64%. For SCE, lower grade, younger age, and undergoing resection significantly improved OS and CSS; treatment without radiotherapy was favorable for OS. Smaller tumor size did not confer a survival benefit. Patients with resected grade 2 spinal cord glioma who did not receive radiotherapy fared well with respect to OS and CSS. For patients with spinal cord glioma, the variables of histology, grade, age and undergoing resection are significant predictors of outcome. Though treatment with radiotherapy was associated with worse outcomes, this may reflect a bias in that patients who underwent radiotherapy were perhaps more likely to have had adverse risk factors. Given the retrospective nature of this study, specific recommendations about which situations warrant radiotherapy cannot be determined.

Vascular gene expression patterns are conserved in primary and metastatic brain tumors.

Malignant primary glial and secondary metastatic brain tumors represent distinct pathological entities. Nevertheless, both tumor types induce profound angiogenic responses in the host brain microvasculature that promote tumor growth. We hypothesized that primary and metastatic tumors induce similar microvascular changes that could function as conserved angiogenesis based therapeutic targets. We previously isolated glioma endothelial marker genes (GEMs) that were selectively upregulated in the microvasculature of proliferating glioblastomas. We sought to determine whether these genes were similarly induced in the microvasculature of metastatic brain tumors. RT-PCR and quantitative RT-PCR were used to screen expression levels of 20 candidate GEMs in primary and metastatic clinical brain tumor specimens. Differentially regulated GEMs were further evaluated by immunohistochemistry or in situ hybridization to localize gene expression using clinical tissue microarrays. Thirteen GEMs were upregulated to a similar degree in both primary and metastatic brain tumors. Most of these genes localize to the cell surface (CXCR7, PV1) or extracellular matrix (COL1A1, COL3A1, COL4A1, COL6A2, MMP14, PXDN) and were selectively expressed by the microvasculature. The shared expression profile between primary and metastatic brain tumors suggests that the molecular pathways driving the angiogenic response are conserved, despite differences in the tumor cells themselves. Anti-angiogenic therapies currently in development for primary brain tumors may prove beneficial for brain metastases and vice versa.

The correlation of fractional anisotropy parameters with Ki-67 index, and the clinical implication in grading of non-enhancing gliomas and neuronal-glial tumors.

PURPOSE: To investigate the correlation between the FA parameters and Ki-67 labeling index, and their diagnostic performance in grading supratentorial non-enhancing gliomas and neuronal-glial tumors (GNGT). METHODS: This institutional review board-approved, Health Insurance Portability and Accountability (HIPAA) compliant retrospective study enrolled 35 patients, including 19 with low grade GNGT and 16 with high grade GNGT. The mean FA, maximal FA and mean maximal FA values derived from diffusion tensor imaging were measured. The correlation between the FA parameters and the Ki-67 labeling index was assessed by Spearman rank test. The receiver operating characteristic curve analysis and multivariate logistic regression analysis were performed to detect the optimal imaging parameters in grading GNGT. RESULTS: The three FA parameters of low grade GNGT were significantly lower than the high grade GNGT (p < 0.001). The mean FA, maximal FA and mean maximal FA had significant positive correlation with Ki-67 labeling index (p = 0.001, p < 0.001, p < 0.001 respectively). The maximal FA showed a higher sensitivity and specificity in grading of non-enhancing GNGT with specificity of 78.9%, sensitivity of 100.0%, respectively. CONCLUSIONS: The FA parameters correlated with Ki-67 labeling index, and were useful surrogates in preoperative grading supratentorial non-enhancing GNGT.

Characterization of TEM1/endosialin in human and murine brain tumors.

BACKGROUND: TEM1/endosialin is an emerging microvascular marker of tumor angiogenesis. We characterized the expression pattern of TEM1/endosialin in astrocytic and metastatic brain tumors and investigated its role as a therapeutic target in human endothelial cells and mouse xenograft models. METHODS: In situ hybridization (ISH), immunohistochemistry (IH) and immunofluorescence (IF) were used to localize TEM1/endosialin expression in grade II-IV astrocytomas and metastatic brain tumors on tissue microarrays. Changes in TEM1/endosialin expression in response to pro-angiogenic conditions were assessed in human endothelial cells grown in vitro. Intracranial U87MG glioblastoma (GBM) xenografts were analyzed in nude TEM1/endosialin knockout (KO) and wildtype (WT) mice. RESULTS: TEM1/endosialin was upregulated in primary and metastatic human brain tumors, where it localized primarily to the tumor vasculature and a subset of tumor stromal cells. Analysis of 275 arrayed grade II-IV astrocytomas demonstrated TEM1/endosialin expression in 79% of tumors. Robust TEM1/endosialin expression occurred in 31% of glioblastomas (grade IV astroctyomas). TEM1/endosialin expression was inversely correlated with patient age. TEM1/endosialin showed limited co-localization with CD31, alphaSMA and fibronectin in clinical specimens. In vitro, TEM1/endosialin was upregulated in human endothelial cells cultured in matrigel. Vascular Tem1/endosialin was induced in intracranial U87MG GBM xenografts grown in mice. Tem1/endosialin KO vs WT mice demonstrated equivalent survival and tumor growth when implanted with intracranial GBM xenografts, although Tem1/endosialin KO tumors were significantly more vascular than the WT counterparts. CONCLUSION: TEM1/endosialin was induced in the vasculature of high-grade brain tumors where its expression was inversely correlated with patient age. Although lack of TEM1/endosialin did not suppress growth of intracranial GBM xenografts, it did increase tumor vascularity. The cellular localization of TEM1/endosialin and its expression profile in primary and metastatic brain tumors support efforts to therapeutically target this protein, potentially via antibody mediated drug delivery strategies.

Increased STAT-3 and synchronous activation of Raf-1-MEK-1-MAPK, and phosphatidylinositol 3-Kinase-Akt-mTOR pathways in atypical and anaplastic meningiomas.

The intracellular events promoting meningioma cell proliferation in high grade tumors are not established. In this study we compared 45 WHO grade I and 35 grade II or III meningiomas by Western blot or immunohistochemistry for phosphorylation/activation of the MEK-1-MAPK, PI3 K-Akt-mTOR-PRAS40 and STAT3 pathways. By Western blot, STAT3 activation was detected in 75% of grade I compared to 100% of grade II and III meningiomas. By immunohistochemistry p-STAT3 was detected in 28% of grade I compared to 65 or 66% of grade II and III meningiomas, respectively. Phosphorylated MEK-1 and p-MAPK were activated in nearly all grade I, II and III tumors. Phosphorylated Akt was also detected in the majority of meningiomas of each grade although downstream pathway component activation was less widespread. These findings suggest that there is increased STAT3 activation in WHO grade II and III meningiomas compared with grade I tumors. Moreover, each of the three major growth regulatory pathways is concomitantly activated in higher grade meningiomas.