Comparison of Predictive Immunohistochemical Marker Expression of Primary Breast Cancer and Paired Distant Metastasis using Surgical Material: A Practice-Based Study.

Parallel studies of primary breast carcinomas and corresponding distant metastases samples reveal considerable differences. Our aim was to highlight this issue from another perspective and provide further data based on 98 patient samples: 69 primary breast carcinoma and 85 distant metastases from bone, central nervous system (CNS) and lung (56 paired). Two independent series of immunohistochemical reactions with different antibodies for estrogen receptor (ER), progesterone receptor (PgR) and human epidermal growth factor receptor 2 (Her2), along with HER2 fluroscence in situ hybridization (FISH) were performed on tissue microarrays to classify breast carcinoma and distant metastases samples into Luminal A, Luminal B-proliferating, Luminal B-HER2+, HER2+ and triple negative (TNBC) surrogate breast cancer groups. Correlation and agreement between the two assessments of ER and PgR were fair-to-moderate, and almost perfect for HER2 and Ki67. There was 40% discordance concerning immunophenotype between breast carcinomas and distant metastases. Most common metastatic site of ER+ breast carcinoma was the skeletal system (59.2%), whereas that of TNBCs was the CNS (58.8%) and lungs (23.5%). Distant metastases in bones were mostly luminal (54.3%), in the CNS, Luminal B (53.2%), and in the lung, TNBC (37.5%). The change of drugable properties of primary breast cancers in the respective bone and CNS metastases suggests that characterization of the metastasis is necessary for appropriate treatment planning.

Effect of Concomitant Radiochemotherapy on Invasion Potential of Glioblastoma.

Glioblastoma (GBM) is the most common primary brain tumor in adults with inevitable recurrence after oncotherapy. The insufficient effect of "gold standard" temozolomide-based concomitant radiochemotherapy may be due to the inability to prevent tumor cell invasion. Peritumoral infiltration depends mainly on the interaction between extracellular matrix (ECM) components and cell membrane receptors. Changes in invasive behaviour after oncotherapy can be evaluated at the molecular level by determining the RNA expression and protein levels of the invasion-related ECM components. The expression of nineteen ECM molecules was determined at both RNA and protein levels in thirty-one GBM samples. Fifteen GBM samples originated from the first surgical procedure on patients before oncotherapy, and sixteen GBM samples were collected at the second surgery due to local recurrence after concomitant chemoirradiation. RNA expressions were measured with qRT-PCR, and protein levels were determined by quantitative analysis of Western blots. Only MMP-9 RNA transcript level was reduced (p < 0.05) whereas at protein level, eight molecules showed changes concordant with RNA expression with significant decrease in brevican only. The results suggest that concomitant radiochemotherapy does not have sufficient impact on the expression of invasion-related ECM components of glioblastoma, oncotherapy does not significantly affect its invasive behavior. To avoid the spread of tumors into the brain parenchyma, supplementation of antiproliferative treatment with anti-invasive agents may be worth consideration in oncotherapy for glioblastoma.

Expression of proliferation markers Ki67, cyclin A, geminin and aurora-kinase A in primary breast carcinomas and corresponding distant metastases.

AIMS: To assess the expression of the following cell cycle regulatory proteins in primary metastatic breast carcinomas (MBCs) and on availability in matched distant metastases (DMs): Ki67, cyclin A, geminin and aurora-kinase A (aurkA); and to compare the expression of these markers in early MBC (EMBC) and late MBC separated into groups according to median time point on metastatic event occurred (28 months). METHODS: The expression of the above mentioned markers was analysed in a total of 47 primary MBCs and 59 DMs (out of which 37 were pairs) by immunohistochemistry. Fourteen breast carcinomas with no relapse over a 10-year follow-up period were utilised as control cases (CBC). RESULTS: Among the MBCs, 22 metastasised to the bone, 4 to the lung and 21 to the central nervous system (CNS). Geminin (p<0.001) and Ki67 (p=0.001) were increased in the MBCs while aurkA and cyclin A showed no difference when compared with CBCs. There were no differences between aurkA, cyclin A and geminin expression in MBCs and DMs in general. Expression of Ki67 was, however, elevated (p=0.027) in DMs. In CNS metastases all markers showed elevated expression as compared to MBCs. In bone metastases, geminin was lower (p<0.001) compared with primary MBCs. In the metastases of the lung, the evaluated markers did not show different expression. According to the median follow-up until the metastatic event, Ki67 was found to be significantly elevated in EMBC (p=0.018). CONCLUSIONS: Ki67 index and geminin distinguish a fraction of MBC with worse prognosis, showing increased levels in the latter in comparison to CBC being tumour-free over a 10-year follow-up period. Ki67 could possibly identify a group of MBCs that develop early DMs.

Symptomatic subependymomas of the ventricles. Review of twenty consecutive cases.

BACKGROUND AND PURPOSE: Intraventricular subependymomas are rare benign tumors, which are often misdiagnosed as ependymomas. To review the clinicopathological features of subependymomas. PATIENT SELECTION AND METHODS: Retrospective clinical analysis of intraventricular subependymomas and systematic review of histological slides operated on at our center between 1985 and 2005. RESULTS: Twenty subependymomas presented at the median age of 50 years (range 19-77). Two (10%) were found in the third, three (15%) in the forth, and 15 in the lateral ventricles. There was male preponderance (12 vs. 8). Ataxia (n=13) and papilledema (n=7) were the most common clinical presentations. Fifteen patients underwent gross total resection, and five had subtotal resection. None of the cases showed mitotic figures, vascular endothelial proliferation or necrosis. Cell proliferation marker MIB-1 activity (percentage of positive staining tumor cells) ranged from 0 to 1.4% (mean 0.3). Two cases were treated with preoperative radiation therapy (50 Gy) before the CT era, three other patients received postoperative radiation therapy for tumors originally diagnosed histologically as low grade ependymomas. Three patients (15%) died of surgical complication between one and three months postoperatively, and three patients died of unrelated causes in eight, 26 and 110 months. Fifteen patients were alive without evidence of tumor recurrence at a median follow-up time of 10 years. CONCLUSION: Subependymomas are low-grade lesions and patients do well without adjuvant radiotherapy. Small samples from more cellular areas may be confused with low grade ependymomas, and unnecessary radiotherapy may follow. Recurrences, rapid growth rates should warrant histological review, as hypocellular areas of ependymomas may also be a source of confusion.

[The role of the pathologist in the diagnosis and therapy planning of central nervous system tumors. Prognostic and predictive markers]. / A patológus szerepe a központi idegrendszer tumorainak diagnosztikájában, a terápiatervezésben. Prognosztikus és prediktív markerek vizsgálata.

Despite advances in imaging methods, the standard of diagnosis and treatment of the tumours of the nervous system remains the histological report issued by a neuropathologist. For reliable, definitive diagnosis, close collaboration with other medical professions is essential, correlation of histological findings with clinical and imaging results is necessary. Neuropathology became a subspecialty because of the specific knowledge and experience it requires. In more complex cases consultation with neuropathologists is important to ensure adequate diagnosis and subsequent treatment. In both establishing the diagnosis and treatment planning, the molecular testing of brain tumors becomes more and more important. These tests are reliably available only in larger centers. Out of the molecular markers, in current practice the investigation of codeletion at 1p/19q, IDH mutations, ß-katenin nuclear positivity and MGMT methylation gained acceptance. Besides these tests already in practice, a vast array of potential diagnostic and prognostic markers are being investigated, which in the future may assist in delivering better and more individualized therapy.

ACTH-secreting Crooke cell carcinoma of the pituitary.

PURPOSE: While pituitary adenomas are common, pituitary carcinomas are rare. It is unclear whether pituitary carcinomas arise de novo or evolve from adenomas. METHODS: We studied the clinical characteristics and tissue samples from eight pituitary surgeries and the autopsy from a patient with pituitary carcinoma. A 16-year-old female patient was diagnosed with an aggressive Crooke cell macroadenoma. Following transsphenoidal surgery, clinical signs of Cushing disease quickly reappeared. During the 14-year course of the illness, eight pituitary surgeries, three courses of extracranial irradiation and two (90) Yttrium-DOTATOC treatments were undertaken. A bilateral adrenalectomy was performed. The patient died of metastatic disease and uncontrolled hypercortisolism due to an adrenal remnant. A systematic morphologic study (histologic staining, electron microscopy) of all available surgical and autopsy specimens was undertaken. RESULTS: Brisk mitotic activity, high Ki-67 and p53 immunolabelling were present in the pituitary samples from the onset. High proportion of tumour cells showed irregular nuclei and large nucleoli, and gradual increase in MGMT staining was observed. The tumour remained of Crooke cell type throughout the course. Autopsy disclosed a postirradiation sarcoma in the pituitary area. CONCLUSIONS: The question whether pituitary carcinomas arise de novo or transform from an adenoma cannot be answered at present with certainty.

Rare angioproliferative tumors mimicking aggressive spinal hemangioma with epidural expansion.

BACKGROUND AND PURPOSE: We present two cases of angio-proliferative tumors that were misdiagnosed and treated as typical hemangiomas with epidural expansion. MATERIALS AND METHODS: Two middle-aged women presented with symptoms and radiological signs characteristic for aggressive hemangioma with epidural expansion. In the first case preoperative embolization and decompressive surgery with open transpedicular vertebroplasty was performed. Within less than a year, epidural recurrence of the tumor prompted for radical excision and corpectomy. The diagnosis after the histological studies and the further clinical evolution was metastasizing leiomyomatosis. No further recurrence occured during the next 6 years. In the second case percutaneous vertebroplasty was performed and complicated by epidural polymethyl-methacrylcate (PMMA) leakage, requiring urgent decompressive surgery. Histological study of the lesion raised the possibility of myopericytoma. This was confirmed 16 months later when complete vertebrectomy was performed due to severe epidural propagation of the recurring tumor. No further recurrence occurred in next the two years. CONCLUSIONS: Rare angio-proliferative tumors, like benign metastasizing leiomyoma and myopericytoma radiologically may resemble aggressive vertebral hemangiomas of the spine. Unlike hemangiomas, such tumors require radical removal due to their likely recurrence. As imaging studies may not be able to completely exclude such pathologies, bone biopsy and thorough histopathological studies are warranted prior to the therapeutic decision.

Brevican, neurocan, tenascin-C and versican are mainly responsible for the invasiveness of low-grade astrocytoma.

The extent of tumor removal determines the effectiveness of postoperative oncotherapy. This is especially true for primary brain tumors, where peritumoral invasion usually makes radical resection impossible. The aim of the study was to determinate the specific expression pattern of invasion related molecules of different intracranial tumors and to identify molecules that are principally responsible for the peritumoral invasiveness of grade II astrocytoma mRNA expression of 26 extracellular matrix (ECM) molecules was determined in tissue samples from grade II astrocytoma, schwannoma, intracerebral metastases of non-small cell lung cancer and normal brain. Immunohistochemical staining for brevican, neurocan, tenascin-C and versican was also performed for each tumor group. Comparing astrocytoma to metastasis, schwannoma and normal brain; and metastasis and schwannoma to normal brain, 22, 17, 20, 21, and 19 molecules, respectively, were found to be significantly overexpressed at the mRNA level. Cluster analysis of mRNA expression showed a specific gene expression pattern for each histological group. Four molecules of 26 were found to be associated to astrocytoma. Immunohistochemical staining confirmed the results of the mRNA analysis at the protein level. Tumors of different origin have a specific invasive phenotype that can evidently determinate on gene expression level. This characteristic expression pattern of the invasion-related molecules might help to screen exact targets for anti-invasion drugs. In case of low-grade astrocytoma. brevican, neurocan, tenascin-C and versican were found to correlate principally with the invasive phenotype of low-grade astrocytoma, thus these molecules can potentially serve as targets for anti-invasion therapy in the future.

[Extracellular matrix of cerebral tumors with different invasiveness]. / Különbözo invazivitású agydaganatok extracelluláris mátrixának expressziója.

OBJECTIVES: Ineffective surgical and radiotherapy of glioblastoma is mainly due to its intensive infiltrating behavior. Contrarily, brain metastases of anaplastic carcinomas are well-circumscribed intracerebral lesions that can be easily exstirpated in most cases. The molecules of the extracellular matrix (ECM) play a pivotal role in the peritumoral infiltration. In this study the mRNA expression of the ECM components was investigated in two types of intracerebral malignoma with different invasion activity. Our aim was to identify the ECM molecules that are responsible for the different intensity of peritumoral infiltration of tumors from different origin. METHODS: The mRNA expression of twenty-three ECM molecules was determined by quantitative reverse transcriptase polymerase chain reaction. Four pieces of glioblastoma and four pieces of intracerebral lung adenocarcinoma metastasis from neurosurgical operation were investigated. Immunohistochemical investigations were performed in case of five molecules. RESULTS: The mRNA expression of nine molecules (brevican, neurocan, neuroglycan-C, syndecan-1,2,4, tenascin-C, versican and matrix-metalloproteinase-[MMP]2) differed significantly by comparison of the two tumor types. By immunohistochemistry, neurocan, syndecan, versican and MMP-2 showed alteration in staining intensity according to the mRNA expression, while MMP-9 showed higher staining intensity in the metastatic tumor. CONCLUSIONS: The identified molecules can play an important role in the different infiltration activity of tumors from different origin. Thus these ECM-components could serve as targets for anti-invasion therapy in the future.

An unusual case of spontaneous subarachnoid haemorrhage - a ruptured aneurysm of a basilar perforator artery.

A 51-year-old gentleman with no significant past medical history presented with a WFNS grade 1 subarachnoid haemorrhage. Initial angiographic investigations revealed no cause, but repeat tests showed a small basilar perforator aneurysm. Following a failed attempt at endovascular treatment, a craniotomy and excision of the aneurysm was performed. Post-operatively the patient made a good recovery. This case highlights the importance of delayed repeat catheter angiography in selected patients with suspicious initial CT head results.

Ependymoma in adults: surgery, reoperation and radiotherapy for survival.

PURPOSE: to retrospectively determine the long-term outcome of adult intracranial ependymoma patients treated with surgery, reoperation, and postoperative radiation therapy. MATERIAL AND METHODS: 61 patients were treated at our institution between 1980 and 2004. Forty patients had World Health Organization (WHO) Grade II ependymoma, and 21 patients had Grade III ependymoma. The median age was 34 years. The majority of patients were female (59%), and 35 had gross total resections (60%). Eighteen patients were reoperated, 15 only once but 2 twice and one six times. Survival times following reoperation was mostly short but some of them reached more than 5 or 10 years. Postoperative radiation therapy was delivered to 31 patients postoperative (55.4%) and to 5 after reoperation, a median total dose of 54 Gy. RESULTS: The median follow-up of surviving patients was 10.6 years. The 5-year and 10-year disease free survival rates for all patients were 50% and 32.9% respectively. The 5-year and 10-year overall survival rates for all patients were 57.1% and 39.4%, respectively. A statistically significant effect on prognosis was observed with WHO tumour grade as well as with MIB-1 labelling index. Subtotal resection predicted a worse overall survival, but this failed to reach statistical significance. No statistically significant effect on prognosis was observed with tumour location and radiation therapy. CONCLUSION: In our experience the use of radiotherapy in adult, intracranial WHO Grade II ependymoma patients had no significant effect on prognosis. Radical surgery and eventual reoperation seems to be more favorable.

[Expression pattern of invasion-related molecules in brain tumors of different origin]. / Különbözo eredetu malignus agydaganatok invazivitásának panelszeru vizsgálata.

Tumor cell invasion into the surrounding brain tissue is mainly responsible for the failure of radical surgical resection and successful treatment, with tumor recurrence as microdisseminated disease. Epidermal growth factor receptors (EGFRs), integrins and their ligands in the extracellular matrix (ECM) predominantly participate in the invasion process, including the cell adhesion to the surrounding microenvironment and cell migration. The extent of infiltration of the surrounding brain tissue by malignant tumors strongly depends on the tumor cell type. Malignant gliomas show much more intensive peritumoral invasion than do metastatic tumors. In this study, the mRNA expression of 29 invasion-related molecules (18 cell membrane receptors or receptor subunits (EGFRs and integrins) and 11 ECM components: collagens, laminins and fibronectin) was investigated by quantitative reverse transcriptase-polymerase chain reaction. Fresh frozen human tissue samples from glioblastoma (GBM) and intracerebral bronchial adenocarcinoma metastases (five pieces from each) were evaluated. Significant differences were established in six of the 29 molecules (ErbB1, 2, 3, integrins alpha3, 7 and beta1). To confirm our results at the protein level, immunohistochemical analysis of nine molecules was performed. The staining intensity differed definitely in the case of ErbB1, 2 and integrins alpha3 and beta1. Determining the differences in invasion-related molecules in tumors of different origin can help identify the exact molecular mechanisms that facilitate peritumoral infiltration by glioblastoma cells. These results should allow the selection of target molecules for potential chemotherapeutic agents directed against highly invasive malignant gliomas.

Effect of somatostatin analogue octreotide in medulloblastoma in xenograft and cell culture study.

BACKGROUND: The effect and possible timing of nonradiolabeled somatostatin analogue octreotide are still not determined in the treatment of medulloblastoma, while the presence of somatostatin receptor type-2 (SSTR2) is proved in the majority of medulloblastoma by several authors. PROCEDURES: Daoy, SSTR2A positive medulloblastoma cell culture was tested with octreotide in monotherapy and combined with cisplatin, etoposide, and vincristine. Daoy medulloblastoma mice xenograft was treated with octreotide alone. RESULTS: In monolayer cell culture high-dose octreotide (44 microM) resulted in mitotic inhibition with parallel increment of apoptosis. Combination with cytostatic drugs did not result in additive or synergistic effect, but vincristine was partially antagonized. In medulloblastoma xenograft, octreotide monotherapy (100 microg/kg/day for 10 days) resulted in partial tumor growth inhibition. CONCLUSIONS: High concentration of nonradiolabeled octreotide may have role in the treatment of medulloblastoma by long-term administration. Concomitant administration of octreotide with widely used cytostatic drugs against medulloblastoma will not have beneficial impact.

A patient with thyrotropinoma cosecreting growth hormone and follicle-stimulating hormone with low alpha-glycoprotein: a new subentity?

BACKGROUND: Thyrotropinomas are rare pituitary tumors. In 25 percent of cases there is autonomous secretion of a second pituitary hormone, adding to the clinical complexity. We report a patient with thyrotropin (TSH)-dependant hyperthyroidism along with growth hormone (GH) and follicle-stimulating hormone (FSH) hypersecretion but low alpha-glycoprotein (alpha-subunit) concentrations, a hitherto unique constellation of findings. SUMMARY: A 67-year-old Scottish lady presented with longstanding ankle edema, paroxysmal atrial fibrillation, uncontrolled hypertension, fine tremors, warm peripheries, and agitation. Initial findings were a small goiter, elevated serum TSH of 7.37 mU/L (normal range, 0.30-6.0 mU/L), a free-thyroxine concentration of 34.9 pmol/L (normal range, 9.0-24.0 pmol/L), a flat TSH response to TSH-releasing hormone, and serum alpha-subunit of 3.1 IU/L (normal, <3.0 IU/L). There was no evidence of an abnormal thyroid hormone beta receptor by genotyping. Serum FSH was 56.8 U/L, but the luteinizing hormone (LH) was 23.6 U/L (postmenopausal FSH and LH reference ranges both >30 U/L) Basal insulin-like growth factor I was elevated to 487 microg/L with the concomitant serum GH being 14.1 mU/L, and subsequent serum GH values 30 minutes after 75 g oral glucose being 19.1 mU/L and 150 minutes later being 13.7 mU/L. An magnetic resonance imaging pituitary revealed a macroadenoma. Pituitary adenomectomy was performed with the histology confirming a pituitary adenoma, and the immunohistochemistry staining showed positive reactivity for FSH with scattered cells staining for GH and TSH. Staining for other anterior pituitary hormones was negative. After pituitary surgery she became clinically and biochemically euthyroid, the serum IFG-1 became normal, but the pattern of serum FSH and LH did not change. CONCLUSION: This case of plurihormonal thyrotropinoma is unique in having hypersecretion of TSH, GH, and FSH with low alpha-subunit. Such a combination may represent a new subentity of TSHomas.

Lateral ventricle gliomas and central neurocytomas in adults diagnosis and perspectives.

Neuroimaging data of lateral ventricle gliomas and central neurocytomas diagnosed in one institution were reviewed and compared to the corresponding literature data. CT and MRI imaging characteristics of the two tumour types are rather different, both in reported cases as well as in our material. In our series ventricular ependymomas (eight cases) were mostly hyperdense with pronounced contrast uptake. Thirteen subependymomas were hypodense, mostly without enhancement, but occasionally mild or moderate enhancement was noted. Eight subependymal giant cell astrocytomas also displayed hypodense, rarely hyperdense or mixed imaging characteristics, and always showed significant degree of contrast enhancement. Nineteen central neurocytomas showed hypo- or mixed density, but mostly mild to moderate enhancement. Ependymomas and anaplastic astrocytomas and glioblastomas followed the characteristics of the similar extraventricular ones. In our series low-grade astrocytomas, WHO I-II [Louis DN, Ohgaki H, Wiestler OD, Canevee WK. WHO classification of tumours of the central nervous system. Lyon: International Agency for Research on Cancer; 2007] were hypodense without contrast uptake. Our data support those of previous studies in that MRI has been found to be superior to CT for a more precise imaging of lateral ventricle gliomas. However, it is of note that for the verification of an intraventricular tumour CT is also satisfactory. Survival data were available in 65 cases, which have confirmed a favourable outcome in most of the patients with subependymoma, subependymal giant cell astrocytoma, central neurocytomas or pilocytic astrocytoma. Survival of patients with other types of glial tumour was similar to that of patients with a similar tumour, but in an extraventricular localisation.

[Examination of somatostatin receptor expression in recurrent childhood medulloblastomas]. / A szomatosztatinreceptor-expresszió változásának vizsgálata recidiváló medulloblastomában.

Medulloblastoma is the most common malignant pediatric central nervous system tumor. Despite the adequate therapy the tumor often recurs. The primary medulloblastoma expresses somatostatin receptor-2 (SSTR-2), but so far we had no experience about the receptor status in recurrent tumors. The presence of SSTR-2 may have an important role in the early detection and treatment of recurrent medulloblastomas. Our aim was to examine the state of SSTR-2 expression in recurrent childhood medulloblastomas. We examined SSTR-2 expression by immunohistochemistry in primary and recurrent medulloblastoma samples of ten children treated with recurrent medulloblastoma at Semmelweis University, Departments of Pediatrics, between 1998 and 2004. All primary and recurrent tumors have been operated at the National Institute of Neurosurgery. We examined the intensity and the percentage of SSTR-2-positive tumor cells in the primary and recurrent tumor samples. All primary tumors were receptor-positive and SSTR-2 was also expressed in all recurrent medulloblastomas. In our samples the percentage of SSTR-2-positive tumor cells was 30-90%. As a positive in vivo control Octreoscan images were available in two cases. In these cases the results of immunohistochemistry and Octreoscan imaging seemed to correlate. As a conclusion, SSTR-2-positive recurrent tumors can be detected early by Octreoscan imaging, and the presence of SSTR-2 establishes the opportunity of applying somatostatin analogues (octreotide) in the treatment of recurrent childhood medulloblastoma.

Protein western array analysis in human pituitary tumours: insights and limitations.

The molecular analysis of pituitary tumours has received a great deal of attention, although the majority of studies have concentrated on the genome and the transcriptome. We aimed to study the proteome of human pituitary adenomas. A protein array using 1005 monoclonal antibodies was used to study GH-, corticotrophin- and prolactin-secreting as well as non-functioning pituitary adenomas (NFPAs). Individual protein expression levels in the tumours were compared with the expression profile of normal pituitary tissue. Out of 316 proteins that were detected in the pituitary tissue samples, 116 proteins had not previously been described in human pituitary tissue. Four prominent differentially expressed proteins with potential importance to tumorigenesis were chosen for validation by immunohistochemistry and western blotting. In the protein array analysis heat shock protein 110 (HSP110), a chaperone associated with protein folding, and B2 bradykinin receptor, a potential regulator of prolactin secretion, were significantly overexpressed in all adenoma subtypes, while C-terminal Src kinase (CSK), an inhibitor of proto-oncogenic enzymes, and annexin II, a calcium-dependent binding protein, were significantly underexpressed in all adenoma subtypes. The immunohistochemical analysis confirmed the overexpression of HSP110 and B2 bradykinin receptor and underexpression of CSK and annexin II in pituitary adenoma cells when compared with their corresponding normal pituitary cells. Western blotting only partially confirmed the proteomics data: HSP110 was significantly overexpressed in prolactinomas and NFPAs, the B2 bradykinin receptor was significantly overexpressed in prolactinomas, annexin II was significantly underexpressed in somatotrophinomas, while CSK did not show significant underexpression in any tumour. Protein expression analysis of pituitary samples disclosed both novel proteins and putative protein candidates for pituitary tumorigenesis, though validation using conventional techniques are necessary to confirm the protein array data.

Gene expression profiling from formalin-fixed paraffin-embedded tumors of pediatric glioblastoma.

PURPOSE: Gene expression profiling has proved crucial for understanding the biology of cancer. In rare diseases, including pediatric glioblastoma (pGBM), the lack of readily available fresh frozen (FF) material limits the feasibility of this analysis, as well as its validation, on independent data sets, a step needed to ensure relevance, mandating the use of alternate RNA sources. To overcome the limitation of material number and to validate results we obtained on FF pGBM, we did microarray analysis on RNA extracted from formalin-fixed, paraffin-embedded archival samples from pGBM and control brains, wherein we had no control on the fixation process. EXPERIMENTAL DESIGN: RNA from 16 pGBM and 3 control brains was extracted and linearly amplified. Reverse transcription-PCR on housekeeping and formerly identified tumor-associated genes and microarray analysis were done on this RNA source. Results were validated by immunohistochemistry. RESULTS: Despite extensive RNA degradation, microarray analysis was possible on 16 of 19 samples and reproduced the pattern of results obtained on FF pGBM. Gene lists and ontology subgrouping were highly concordant in both sample types. Similar to the findings on FF samples, we were able to identify two subsets of pGBM based on their association/lack of association with evidence consistent with an active Ras pathway. CONCLUSIONS: Archival formalin-fixed, paraffin-embedded tissues are an invaluable resource as they are the most widely available materials often accessible in conjunction with clinical and follow-up data. Gene expression profiling on this material is feasible and may represent a significant advance for understanding the biology of rare human diseases.

Molecular profiling identifies prognostic subgroups of pediatric glioblastoma and shows increased YB-1 expression in tumors.

PURPOSE: Pediatric glioblastoma (pGBM) is a rare, but devastating brain tumor. In contrast to GBM in adults (aGBM), little is known about the mechanisms underlying its development. Our aim is to gain insight into the molecular pathways of pGBM. MATERIALS AND METHODS: Thirty-two pGBM and seven aGBM samples were investigated using biochemical and transcriptional profiling. Ras and Akt pathway activation was assessed through the phosphorylation of downstream effectors, and gene expression profiles were generated using the University Health Network Human 19K cDNA arrays. Results were validated using real-time polymerase chain reaction and immunohistochemistry and compared with existing data sets on aGBM. RESULTS: There are at least two subsets of pGBM. One subset, associated with Ras and Akt pathway activation, has very poor prognosis and exhibits increased expression of genes related to proliferation and to a neural stem-cell phenotype, similar to findings in aggressive aGBM. This subset was still molecularly distinguishable from aGBM after unsupervised and supervised analysis of expression profiles. A second subset, with better prognosis, is not associated with activation of Akt and Ras pathways, may originate from astroglial progenitors, and does not express gene signatures and markers shown to be associated with long-term survival in aGBM. Both subsets of pGBM show overexpression of Y-box-protein-1 that may help drive oncogenesis in this tumor. CONCLUSION: Our work, the first study of gene expression profiles in pGBM, provides valuable insight into active pathways and targets in a cancer with minimal survival, and suggests that these tumors cannot be understood exclusively through studies of aGBM.

Nodule formation and desmoplasia in medulloblastomas-defining the nodular/desmoplastic variant and its biological behavior.

Among the variants of medulloblastoma in the current WHO classification of nervous system tumors, the desmoplastic variant, which has been reported to constitute 5%-25% of pediatric medulloblastomas, is defined by its nodular collections of neurocytic cells bounded by desmoplastic internodular zones. We have studied the frequency, morphological features and biological behavior of medulloblastomas in two contemporaneous SIOP/UKCCSG trial cohorts of children with medulloblastomas, CNS9102 (n = 315) and CNS9204 (n = 35), focusing on tumors with nodular and desmoplastic phenotypes. In children aged 3-16 years (CNS9102), the nodular/desmoplastic medulloblastoma represented 5% of all tumors, while in infants aged <3 years (CNS9204) this variant represented 57% of medulloblastomas. Using iFISH to detect molecular cytogenetic abnormalities in medulloblastomas with a nodular architecture, we demonstrated distinct genetic profiles in desmoplastic and non-desmoplastic (classic and anaplastic) tumors; in particular, abnormalities of chromosome 17 occurred in the latter, but not the former. Significantly different outcomes were demonstrated for classic, nodular/desmoplastic and large cell/anaplastic medulloblastomas in both cohorts. In conclusion, the nodular/desmoplastic medulloblastoma appears to have clinical, genetic and biological characteristics that set it apart from other variants of this tumor.