The proposed studies utilize molecular probes to neurofilament (NF) proteins to characterize the full nature of NF protein alterations which occur during the transformation of the neuronal genotype in neoplastic conditions of the human nervous system. Biochemical methods will be combined with immunocytochemical applications of these probes. Comparisons will be made to determine the extent to which NF triplet proteins of transformed neurons are similar to or different from the NF protein subunits of immature, developing and mature neurons. Studies will be conducted to elucidate the mechanisms underlying NF abnormalities in transformed neurons using two neoplastic human cell lines derived from an embryonal carcinoma and a medulloblastoma. The replicating cells of the embryonal carcinoma cell line express keratin rather than NF proteins, but they can be induced to differentiate into non-dividing, neurons that express normal NF triplet proteins and no longer contain keratin proteins. In contrast, cells in the medulloblastoma cell line divide rapidly, are undifferentiated, and express all three NF subunits. However, the NF in these cells are abnormal. The molecular probes we will use to accomplish our objectives will be selected from our large and well-characterized library of monoclonal antibodies to human NF proteins. They recognize immunologically distinct, posttranslationally modified variants of each NF subunit that result from the differential phosphorylation of """"""""nascent"""""""" NF polypeptides. The complement our analysis of epigenetic mechanisms leading to NF abnormalities in transformed neurons, cDNA probes to human NF triplet protein mRNAs will be used to evaluate genetic mechanisms which may also account for these derangements. The accomplishment of these specific aims will: 1) Establish molecular criteria for the diagnostic and prognostic assessment of neuronal tumors; 2) Define the extent to which neoplastic NF proteins are deranged relative to those in normal mature and immature human neurons; 3) Elucidate mechanisms leading to abnormal NF expression in neoplastic neurons. This work has important implications for understanding the multi-step process of transformation and tumor progression, and it will lead to improvements in the management of patients with neuron derived malignancies.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37CA036245-08
Application #
3482330
Study Section
Pathology A Study Section (PTHA)
Project Start
1983-12-01
Project End
1991-11-30
Budget Start
1990-12-01
Budget End
1991-11-30
Support Year
8
Fiscal Year
1991
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Fung, Kar-Ming; Rorke, Lucy B; Giasson, Benoit et al. (2003) Expression of alpha-, beta-, and gamma-synuclein in glial tumors and medulloblastomas. Acta Neuropathol (Berl) 106:167-75
Janss, A J; Maity, A; Tang, C B et al. (2001) Decreased cyclin B1 expression contributes to G2 delay in human brain tumor cells after treatment with camptothecin. Neuro Oncol 3:11-21
Thomson, J A; Marshall, V S; Trojanowski, J Q (1998) Neural differentiation of rhesus embryonic stem cells. APMIS 106:149-56;discussion 156-7
Lasner, T M; Tal-Singer, R; Kesari, S et al. (1998) Toxicity and neuronal infection of a HSV-1 ICP34.5 mutant in nude mice. J Neurovirol 4:100-5
Kesari, S; Lasner, T M; Balsara, K R et al. (1998) A neuroattenuated ICP34.5-deficient herpes simplex virus type 1 replicates in ependymal cells of the murine central nervous system. J Gen Virol 79 ( Pt 3):525-36
Janss, A J; Levow, C; Bernhard, E J et al. (1998) Caffeine and staurosporine enhance the cytotoxicity of cisplatin and camptothecin in human brain tumor cell lines. Exp Cell Res 243:29-38
Janss, A J; Cnaan, A; Zhao, H et al. (1998) Synergistic cytotoxicity of topoisomerase I inhibitors with alkylating agents and etoposide in human brain tumor cell lines. Anticancer Drugs 9:641-52
Biegel, J A; Janss, A J; Raffel, C et al. (1997) Prognostic significance of chromosome 17p deletions in childhood primitive neuroectodermal tumors (medulloblastomas) of the central nervous system. Clin Cancer Res 3:473-8
Lasner, T M; Kesari, S; Brown, S M et al. (1996) Therapy of a murine model of pediatric brain tumors using a herpes simplex virus type-1 ICP34.5 mutant and demonstration of viral replication within the CNS. J Neuropathol Exp Neurol 55:1259-69
Kesari, S; Lee, V M; Brown, S M et al. (1996) Selective vulnerability of mouse CNS neurons to latent infection with a neuroattenuated herpes simplex virus-1. J Neurosci 16:5644-53

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