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PubMed1996

Neurotrophin and neurotrophin receptor proteins in medulloblastomas and other primitive neuroectodermal tumors of the pediatric central nervous system.

Primitive neuroectodermal tumors (PNETs) of the central nervous system (CNS) are poorly understood childhood neoplasms, and medulloblastomas are the most common pediatric PNETs. Neoplastic cells in medulloblastomas and other PNETs resemble progenitor cells of the developing central nervous system, but they also may exhibit the molecular phenotype of immature neurons or glia. As neurotrophins play a role in regulating differentiation, proliferation, and cell death in the normal developing central nervous system, and recent evidence suggests that neurotrophins may influence the behavior of medulloblastomas, we studied 29 PNET biopsy samples (27 of which were posterior fossa medulloblastomas) by immunobistochemistry using antibodies specific for each of the major high affinity neurotrophin receptor proteins, ie, TrkA, TrkB, and TrkC. A subset of these tumors also was examined by Western blot. Immunoreactive TrkA, TrkB, and TrkC were observed in neoplastic cells in 8 (27%), 18 (62%), and 14 (48%) of these PNETs, respectively. Additional immunohistochemical studies of a subset of these PNETs using antibodies to neurotrophins that primarily activate TrkB and TrkC, ie, brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4/5, showed that immunoreactive brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4/5 were detected in 22, 9, and 19% of these PNET biopsies, respectively. Finally, 19 pediatric brain tumors other than these PNETs also were studied here, and they expressed these neurotrophins and their receptors to a variable extent. The demonstration here that neurotrophins and their cognate receptor proteins are expressed in PNETs as well as in other pediatric brain tumors may imply that signal transduction pathways mediated by neurotrophins and/or their receptors influence the induction or progression of these common childhood neoplasms.

Adolescent↗
PubMed1996

Expression of memory, differentiation, and repression of c-myc and p53 genes in human RD/TE-671 cells induced by a ureido-derivative of pyridine (UDP-4).

Human TE-671 cells have been used to study several aspects of neuroectodermal tumors in culture. Since the human TE-671 cell lines has been re-identified as a rhabdomyosarcoma (RD) rather than a medulloblastoma due to the presence of muscle-type nicotinic acetylcholine receptors, we re-investigated the nature of RD/TE-671 cells and characterized their differentiation induced by 2-(3-ethylureido)-6-methylpyridine (UDP-4), a potent inducer of differentiation of neoplastic cells. RD cells were also used for comparative studies. RD/TE-671 cells exposed to UDP-4 were differentiated irreversibly into postmitotic cells expressing mainly neurofilaments and, to a lesser extent, myoid proteins. In contrast to RD cells that expressed preferentially myoid and not neurofilament proteins (NFPs) upon treatment with UDP-4, differentiated RD/TE-671 cells exhibited characteristic dendritic processes and expressed NFPs (NFP68, NFP160, and NFP200), parvalbumin (calcium-binding protein), and neuron-specific enolase, as well as a small amount of vimentin and desmin. In addition, differentiated RD/TE-671 cells expressed memory for differentiation and underwent an irreversible limitation of proliferation, loss of clonogenic potential, selective repression of c-myc and p53 proto-oncogenes, and changes in cell surface architecture. Treatment of RD/ TE-671 cells with nerve growth factor or epidermal growth factor in the presence of UDP-4 did not alter the phenotype of differentiated cells, whereas co-treatment with 12-O-tetradecanoylphorbol-13-acetate and UDP-4 enhanced morphological differentiation. Therefore, we conclude that: (a) RD/TE-671 cells challenged with UDP-4 express memory to differentiate in the absence of inducer; (b) in contrast to RD cells, RD/TE-671 cells appear to be multipotent cells of neuroectodermal origin capable of differentiation into cells expressing neuronal rather than myoid proteins upon treatment with UDP-4; and (c) differentiation of RD/TE-671 cells leads to selective cessation of cell proliferation and repression of c-myc and p53 proto-oncogenes.

Cell Differentiation↗
PubMed1996

Insulin-like growth factor I receptor-mediated circuit in Ewing's sarcoma/peripheral neuroectodermal tumor: a possible therapeutic target.

The disappointingly low survival rate observed in Ewing's sarcoma (ES)/peripheral neuroectodermal tumor (PNET) despite the adoption of aggressive multimodal treatments prompted us to study the existence of autocrine circuits to be used as innovative therapeutic targets. Of the several circuits analyzed, only the insulin-like growth factor receptor (IGF-IR)-mediated loop was found to be constantly present both in cell lines and clinical samples, suggesting a role for this autocrine circuit in the pathogenesis of ES/PNET. The in vitro inhibition of the IGF-IR-mediated circuit by the specific IGF-IR binding antibody alphaIR3 suppressed the growth of ES/PNET cells by decreasing the proliferative rate and increasing apoptosis. alphaIR3 also significantly inhibited the ability of ES/PNET cells to grow in soft agar and to migrate following a chemotactic stimulus. Inactivation of the IGF-IR signaling pathway may therefore be considered as an effective therapeutic modality for patients with ES/PNET.

Antibodies↗
PubMed1996

[A case report of dysembryoplastic neuroepithelial tumor associated with neurofibromatosis type 1].

Dysembryoplastic neuroepithelial tumor (DNT) in a newly proposed mixed neuroglial tumor in the cerebral cortex. However, DNT associated with phacomatosis has mostly been considered exceptional. In this paper, a case of DNT associated with neurofibromatosis type 1 is reported. A 23-year-old male was admitted to our hospital complaining of intractable complex-partial seizure. He had a history of neurofibromatosis type 1 (NF - 1) and pituitary dwarfism. On general physiological examination, many cafe au lait spots and freckling could be noted, showing that the case was neurofibromatosis type 1. In addition, neurological examination showed no abnormal findings. MR images revealed a small area of abnormal intensity on the right temporal. This region showed high intensity on T2 weighted image and low intensity without enhancement on T1 weighted image. On electroencephalography (EEG), an epileptic spike focus was demonstrated in the right temporal lobe. So, lobectomy was performed for control of epilepsy. Postoperative course was uneventful and without seizure. On histological examination, the tumor was composed of three different components : specific glioneural element, foci of oligodendrocyte-like cell, and cortical dysplasia. All of these findings were consistent with the definition of DNT by Daumas-Duport et al, except for the association with NF - 1. Although reported cases of DNT associated with FN - 1 are exceptionally rare, both DNT and NF - 1 originate from maldevelopment of the fetal central nervous system. It is very interesting that our case indicated the possibility of co-existence of both diseases.

Adult↗
PubMed1996

Dysembryoplastic neuroepithelial tumors: MR and CT evaluation.

PURPOSE: To evaluate dysembryoplastic neuroepithelial tumors (DNTs) on MR and CT studies and to compare DNT with other frequently encountered epileptogenic glioneuronal lesions. METHODS: We analyzed the MR images and CT scans of 16 patients who had complex partial epilepsy and DNT with respect to tumor location, size, CT density, MR signal intensity, mass effect, contrast enhancement, and heterogeneity, and compared these features with CT and MR findings in 51 cases of ganglioglioma and 33 cases of glioneuronal malformation. RESULTS: DNTs were located in the temporal lobe in 14 patients and in the frontal lobe in 2 patients. The cortex was involved in all cases and the subcortical white matter in 10 cases. Fifty percent of the tumors had poorly defined contours. On MR images, 14 DNTs had multiple cysts and 2 had single cysts. Contrast enhancement was observed in 6 DNTs, and mass effect was present in 9. CT scans disclosed moderately hypodense lesions in 7 patients and markedly hypodense cystic lesions in 6 patients. Two DNTs were calcified. Tumor hemorrhage with perifocal edema was observed in 1 case. Contrary to previous reports, slow but definite tumor growth was present during a 13-year period in 2 of 6 patients in whom serial CT or MR studies were obtained. CONCLUSION: A multicystic appearance on MR images is a characteristic feature of DNT and corresponds to its myxoid matrix and multinodular architecture. This feature is rare in gangliogliomas and glioneuronal malformations, and, as such, may help differentiate DNTs from these disorders.

Adolescent↗
PubMedDate not supplied

Dysembryoplastic neuroepithelial tumor: a clinicopathologic and immunohistochemical study of 11 tumors including MIB1 immunoreactivity.

The dysembryoplastic neuroepithelial tumor (DNT) is a rare, recently recognized neoplasm, characterized by a mixed glial-neuronal cell proliferation. We studied 11 cases of DNT including 6 males and 5 females (age range 2.1-39.4 years, mean 13.8 years). All patients presented with chronic epilepsy of 4.8 years mean duration. Nine tumors were located in the temporal lobe and 2 in the frontal lobe. Four tumors were located on the right side and 7 on the left. All tumors were characterized by a predominant oligodendrocyte-like cell component with intermixed normal appearing neurons and astrocytes. All were focally microcystic and 7 of 9 evaluable tumors were multinodular. Other observed histologic features included a focal arcuate vascular pattern in 7 tumors, calcification in 4 tumors, and a rare mitotic figure in 2 tumors. Necrosis and vascular hyperplasia were not observed in any of the tumors. Cortical architectural disorganization (cortical dysplasia) was observed in 9 of 10 evaluable cases. MIB1 (a marker of cellular proliferation) immunostaining was performed in all 11 tumors and MIB1 indices (number of positive tumor cells/100 tumor cells counted) ranged from 0-0.6 (mean 0.2). Four patients required at least 1 additional surgical procedure for tumor recurrence, related to an incomplete initial excision 2.1-4.4 years after their initial operation. All patients are seizure-free at their last follow-up. DNTs are low grade neoplasms which typically present with chronic epilepsy, are most frequently located in the temporal lobe, and occur most frequently in pediatric patients. Their appearance and association with cortical dysplasia suggest a maldevelopmental origin. The generally slow growth and relatively benign nature of DNT is reflected by their low MIB1 index.

Adolescent↗
PubMedDate not supplied

Temporal lobe lesion demonstrating features of dysembryoplastic neuroepithelial tumor and ganglioglioma: a transitional form?

We report an unusual multimodular glioneuronal lesion found in a temporal lobe from a 17-year-old boy with complex partial seizure. Histologically, this lesion was located within the cortex of the middle temporal gyrus and consisted of multinodular foci and the surrounding cortical dysplasia, resembling dysembryoplastic neuroepithelial tumor (DNT). However, it was quite different in the following respects from usual DNT: 1 nodule found in the subpial area consisted entirely of mature atypical neuronal cells separated by a reticulin fiber network connecting to the pia mater and the area around and between the above nodule, whereas another neighboring nodule, which contained many oligodondroglia-like round cells as well as occasional neuronal cells and fibrillary astrocytic cells, showed scattered neuronal cells in the well-differentiated fibrillary astrocytic stroma, the histological features being those of ganglioglioma (GG). We consider that the present case is a good example of the transitional form between DNT and GG. At 25 months following total lesion extirpation, the patient is healthy and free from seizures.

Adolescent↗
PubMed1997

Dysembryoplastic neuroepithelial tumour of the central nervous system--a case report.

Dysembryoplastic neuroepithelial tumour (DNT) of the central nervous system is a recently recognized entity. We describe the clinical and characteristic histomorphological features in a patient with DNT. As this lesion carries a favourable prognosis, it becomes essential to make an accurate histopathological diagnosis.

Central Nervous System Diseases↗
PubMedDate not supplied

Esthesioneuroblastoma: a general review of the cases published since the discovery of the tumour in 1924.

Esthesioneuroblastoma (ENB) arises from the neuroepithelium in the olfactory rim of the nasal cavity. It accounts for about 3% of all intranasal tumours. Reviews since the first description by Berger and Luc in 1924 never reported more than a hundred cases, stressing the rarity of the tumour. However, a thorough literature review revealed a total of 945 reported cases. In our search we found a total of 1,457 cases chronicled in the literature of which perhaps 487 were cited in more than one paper, bringing the total of reported cases to 945. Author cases accounted for 198 and therefore collaborative efforts accounted for 747 cases. Sex distribution was 53.36% male and 46.64% female. Kadish classification was applied to 553 cases revealing 103 (18.29%) class A cases, 182 (32.33%) class B and 278 (49.38%) class C cases. This distribution was generally stable through the decades. Treatment could be classified in 898 cases. It consisted of surgery alone in 25.17% (226 cases), radiotherapy alone in 18.37% (165 cases), combined surgery and radiotherapy in 43.21% (388 cases) and chemotherapy in 13.2% (119 cases), followed in 11 cases (1.22%) by bone marrow transplant. In the reported cases an overall follow up could be evaluated in 477 cases, while in only 234 cases a five-year follow up was done. The outcome was 68.38% alive and disease free, 12.82% alive with disease and 18.80% dead. From these 20.51% had surgery only, 11.11% radiotherapy and 68.38% combined surgery and radiotherapy. The best survival rates were obtained by combined therapy (72.5% vs. 62.5% surgery alone and 53.85% radiotherapy alone). Death rates were highest after radiotherapy alone (30.77% versus 18.75% in combined therapy and 12.50% after surgery alone). In conclusion, ENB is a rare but not exceptional tumour. It is best treated with combined surgery and radiotherapy. Unfortunately early diagnosis is still uncommon and no significant changes to the proportions of Kadish classes at first diagnosis have been noted in recent decades. A greater awareness of the tumour and earlier diagnosis seems the major focus for future research.

Adolescent↗
PubMed1997

Stem cell factor suppresses apoptosis in neuroblastoma cell lines.

Stem cell factor (SCF) is a glycoprotein growth factor produced by marrow stromal cells that acts after binding to its specific surface receptor, which is the protein encoded by the protooncogene c-kit. SCF synergizes with specific lineage factors in promoting the proliferation of primitive hematopoietic progenitors, and has been administered to expand the pool of these progenitors in cancer patients treated with high-dose chemotherapy. SCF and its c-kit receptor are expressed by some tumor cells, including myeloid leukemia, breast carcinoma, small cell lung carcinoma, melanoma, gynecological tumors, and testicular germ cell tumors. Previous studies of SCF in neuroblastoma have produced conflicting conclusions. To explore the role of SCF in neuroblastoma, we studied five neuroblastoma lines (IMR-5, SK-N-SH, SK-N-BE, AF8, and SJ-N-KP) and the neuroepithelioma line CHP-100. All lines expressed mRNA for c-kit and c-kit protein at low intensity as measured by flow cytometry, and secreted SCF in medium culture as shown by ELISA. Exogenous SCF did not modify 3H thymidine uptake in the neuroblastoma and neuroepithelioma cell lines. After 6 days' culture in the presence of anti-c-kit, the number of viable neuroblastoma cells was significantly lower than the control, and terminal deoxynucleotidyl transferase assay showed a substantial increase of apoptotic cells: The percentage of positive cells was 1-3% in the control lines, whereas in the presence of anti c-kit it varied from 29% of SK-N-BE to 92% of CHP-100. After 9 days' culture in the presence of anti-c-kit, no viable cells were detectable. These data indicate that SCF is produced by some neuroblastoma cell lines via an autocrine loop to protect them from apoptosis.

Antibodies, Monoclonal↗
PubMed1998

Phase II trial of topotecan administered as 72-hour continuous infusion in children with refractory solid tumors: a collaborative Pediatric Branch, National Cancer Institute, and Children's Cancer Group Study.

The antitumor activity of topotecan administered as a 72-h continuous i.v. infusion was evaluated in children with refractory neuroblastoma and sarcomas of soft tissue and bone. We also attempted to increase the dose intensity of topotecan by including an intrapatient dose escalation in the trial design. Ninety-three children (85 eligible and evaluable for response) with recurrent or refractory neuroblastoma, osteosarcoma, Ewing's sarcoma/peripheral neuroectodermal tumor, rhabdomyosarcoma, or other soft-tissue sarcomas received topotecan administered as a 72-h i.v. infusion every 21 days. The initial dose was 1.0 mg/m2/day, with subsequent intrapatient dose escalation to 1.3 mg/m2/day for those patients who did not experience dose-limiting toxicity after their first cycle of topotecan. There was one complete response in a patient with neuroblastoma (n = 26) and one partial response in a patient with Ewing's sarcoma/peripheral neuroectodermal tumor (n = 25). No complete or partial responses were observed in 17 patients with osteosarcoma, 15 patients with rhabdomyosarcoma, or 2 patients with other soft-tissue sarcomas; however, 8 patients had prolonged (15-48 weeks) stable disease while receiving topotecan. Topotecan was well tolerated. The most commonly observed toxicities were myelosuppression (dose-limiting) and nausea and vomiting. Intrapatient dose escalations were performed in 68% of the patients who received more than one cycle of topotecan, and 1.3 mg/m2/day was tolerated by 79% of the patients who received the higher dose and were evaluable for hematological toxicity. In conclusion, topotecan administered as a 72-h continuous infusion every 21 days is inactive (objective response rate, < 20%) in children with refractory or recurrent neuroblastoma and sarcomas of soft tissue or bone.

Adolescent↗
PubMedDate not supplied

Ultrasonic fragmentation for vitrectomy and associated surgical procedures.

Ultrasonic fragmentation (USF) can be used to fragment various tissues such as the lens, the vitreous, the iris, and the ciliary body, so that they may be aspirated through a 23-gauge canula. Since the technique was first described in 1973, it has been used in 148 eyes in a variety of conditions with encouraging results. In aphakic bullous keratopathy, the corneas and vision improved in 78% of the cases. Pupillary block was relieved in 100% of cases. Cystoid macular edema improved in 63%. Vitreous opacification from other than hemorrhage cleared in all cases, and vision improved in 71%. Massive vitreous hemorrhage was cleared in 86%, and vision improved in 58%. In massive vitreous hemorrhage and retinal detachment, the vitreous was cleared and the retina reattached in 80% of cases. In massive vitreous contraction, the vitreous was removed in all cases and the retina reattached in all (100%) of cases. In massive vitreous membranes and retinal detachment, the membranes were successfully removed in 100% and the retina reattached in 82%. Lens remnants in the vitreous were removed in 100% of cases. Secondary membranes were removed successfully in 100% of cases. Vitreous presentation in the anterior chamber, caused by a ruptured posterior capsule during extracapsular extraction or actual vitreous loss during intracapsular extraction, was treated successfully in 100% of cases. One case of medullo-epithelioma of the ciliary body was removed but recurred twice after ultrasonic fragmentation. Complications occurred in seven of 148 cases (4.8%) and consisted of five cases of retinal detachment (probably because of lens material reaction) and two cases of epithelial downgrowth in cases where the wound was not closed with sutures. Ultrasonic fragmentation appears to be a fairly simple procedure, performed with a machine with no moving parts, through two 1-mm incisions and using two 0.6-mm cannulas, with a minimum of complications and encouraging results. It should be tried before more radical procedures are recommended. A good anatomic result was obtained in 129 of the 148 consecutive cases (88%). The technique is described and the results reported.

Abscess↗
PubMed1998

Telomerase activity and alterations in telomere length in human brain tumors.

Telomerase activity was examined in 170 human brain tumor tissues, and terminal restriction fragment (TRF) length was examined in 152 of the 170. Telomerase activity was detected in 61.7% (66 of 107) of the neuroepithelial tumors. However, the detection rates of telomerase activity were widely different for different histopathological entities. In the case of astrocytic tumors, the detection rate was 20.0% (3 of 15) for grade II astrocytomas, 40.0% (6 of 15) for anaplastic astrocytomas, and 72.3% (34 of 47) for glioblastomas. The mean TRF length of the tumors with telomerase activity was significantly shorter than that of the tumors with undetectable telomerase activity for each tumor entity. In grade II and anaplastic astrocytomas, telomerase activity was an indicator of early histological progression and reduced survival of the patients, although there was no difference in MIB-1 staining indices between the tumors with and without telomerase activity at onset. In three astrocytic tumors, concurrence of telomere shortening and telomerase reactivation was observed at recurrence; in these cases, tumors progressed to a higher grade. Ten glioblastomas that progressed from lower-grade tumors exhibited telomerase activity, and their TRF lengths were reduced in 80% (8 of 10). In contrast, telomerase activity was detected in only 63.3% (19 of 30; P < 0.05) and the TRF length remained compatible with normal values in 56.7% (17 of 30; P < 0.01) of de novo glioblastomas. Thus, telomerase activity strongly correlated with potential tumor progression in the short term as well as with progression itself of the astrocytic tumors, whereas telomeres may still have been in the process of shortening in some of the de novo glioblastomas. High telomerase activity was exhibited in all primitive neuroectodermal tumors, anaplastic oligoastrocytomas, neuroblastomas, and oligodendrogliomas. TRF length was reduced in the majority (14 of 15) of three previously high-grade tumors, whereas it was compatible with that of normal brain tissues in the oligodendrogliomas, suggesting that telomerase activity with shortened telomeres correlates with the aggressive growth of high-grade neuroepithelial tumors. Tumor cell lines could be established from 17.2% (5 of 29) of neuroepithelial tumors with telomerase activity but not from tumors without this activity (P < 0.05), suggesting that telomerase reactivation is an essential event in the neuroepithelial cell immortalization in vitro. In nonneuroepithelial tumors, telomerase activity was detected in malignant tumors, such as germ cell tumors, lymphomas, metastatic adenocarcinomas, hemangiopericytomas, and an anaplastic meningioma. In contrast, such activity was not detected in benign tumors, including meningiomas, pituitary adenomas, hemangioblastomas and schwannomas, except for one hemangioblastoma that recurred four times and displayed malignant features at the fourth recurrence. These findings suggest that telomerase activity can be an index of malignant potential or malignancy itself in nonneuroepithelial brain tumors.

Adolescent↗
PubMed1998

Olfactory neuroblastoma (esthesioneuroblastoma) and esthesioneuroepithelioma: histologic and immunohistochemical study.

Two cases of olfactory neuroblastoma (ONB) representing two morphological variants of the tumor are described. Case 1 exhibited a neuroblastoma-like histological pattern corresponding to the usually reported type of ONB--the esthesioneuroblastoma, whereas in case 2 a very rare variant of ONB-the esthesioneuroepithelioma was recognized. The histological and immunohistochemical differences between the cases are discussed with regard to still controversial opinions concerning the subclassification of ONB and the histogenesis and clinical prognosis of these tumors.

Adolescent↗
PubMedDate not supplied

Infratentorial dysembryoplastic neuroepithelial tumor (DNT) associated with Arnold-Chiari malformation.

Dysembryoplastic neuroepithelial tumor (DNT), a benign neoplasm, is now a well recognized clinicopathological entity. We report the second case of DNT in the cerebellum occurring in a 20-year-old male presenting with ataxia. He also had Arnold-Chiari malformation of the adult type. Histologically the tumor was a "simple" DNT having the specific "glioneuronal" element, namely oligodendrocyte-like cells (OLCs), mucoid change and floating neurons (Purkinje cells). A striking feature was the perpendicular arrangement of the neuropil columns extending from the pial surface to white matter similar to those seen in supratentorial examples. On immunstaining some of the OLCs were positive for synaptophysin and negative for glial fibrillary acidic protein (GFAP), glucocerebroside, tau and MAP-2. The neuropil was synaptophysin-positive and focally positive for MAP-2 and GFAP as well. The Purkinje cells were morphologically normal but malaligned and were positive for phosphorylated neurofilament suggesting secondary dysplastic changes. A transition of the lesion into relatively normal cerebellum preserving the folial architecture was observed. The histological and immunochemical features of the DNT in cerebellum suggests its possible origin from the pluripotential external granular layer.

Adult↗