These studies focus on fibronectin (FN)-mediated adhesion mechanisms of human and rodent neuroblastoma cells in culture model systems, as well as the mechanisms of immortalized hybrid F11 cells (rat dorsal root neurons X mouse neuroblastoma cells). They examine the significance of these mechanisms in neuritogenesis in vitro and tumorigenesis in vivo. Subcloning of F11 cells and several experimental approaches have led to isolation and classification of stable subpopulations that have segregated multiple and overlapping mechanisms of differentiation on FN and other molecularly-specific matrices. Proteolytic fragments of FNs and model matrix binding proteins have been used to map at least four independent or cooperative mechanisms of neuritogenesis, utilizing four different cell surface """"""""receptors"""""""" of these neuronal tumor cells--RGDS (Arg-Gly-Asp-Ser)- dependent integrin binding of FNs; a new cell-binding site in FNs--RGDS- independent, located N-terminal of alternately-spliced Edb sequences, and directed to an unidentified receptor; binding to cell surface heparin sulfate proteoglycan; and ganglioside GM1-dependent binding. In addition proteoglycan or ganglioside binding in some experimental contexts can modulate neuritogenesis mediated by other receptor classes on the cell surface. To analyze further the FN adhesion mechanisms of these neuronal tumor cells and their biological significance, three specific aims are proposed: (1) We will characterize a newly-discovered cell adhesion mechanism that mediates neuritogenesis of neuronal tumor cells on FN matrices, the cell surface receptor that mediates its action, its cell-type specificity, and the interplay between this mechanism and other known adhesion mechanisms of FNs. (II) We will evaluate regulation of the multiple mechanisms of neuritogenesis in dorsal root neuron hybrid subclones by the interaction of """"""""cis-acting"""""""" proteoglycans and/or gangliosides with FN receptor molecules at the cell surface, as well as intercellular regulation of differentiation by medium-secreted components in mixed cell populations. (III) We will characterize the early events in neuronal tumor progression in an athymic nude mouse model system, using novel bacterial marker genes for ease of identification of neuronal tumor cells in various organ sites, and the significance of cell type-specific adhesion mechanisms in neuronal tumor progression. Overall, these analyses are demonstrating the complexity and multiplicity of FN binding reactions for mediating adhesion processes by these neuronal tumor derivative cells in two biological contexts - as model systems of neuritogenesis of the embryonic neuronal populations from which these tumor cells were derived and as evaluators of the specialized tumor progression events of these nervous system-derived tumor systems.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS017139-14
Application #
2263160
Study Section
Pathobiochemistry Study Section (PBC)
Project Start
1981-04-01
Project End
1996-03-31
Budget Start
1994-04-01
Budget End
1996-03-31
Support Year
14
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Case Western Reserve University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
077758407
City
Cleveland
State
OH
Country
United States
Zip Code
44106
Culp, L A; Lin, W C; Kleinman, N R (1999) Tagged tumor cells reveal regulatory steps during earliest stages of tumor progression and micrometastasis. Histol Histopathol 14:879-86
Culp, L A; Lin, W C; Kleinman, N R et al. (1998) Tumor progression, micrometastasis, and genetic instability tracked with histochemical marker genes. Prog Histochem Cytochem 33:XI-XV, 329-48
Culp, L A; Lin, W; Kleinman, N R et al. (1998) Earliest steps in primary tumor formation and micrometastasis resolved with histochemical markers of gene-tagged tumor cells. J Histochem Cytochem 46:557-68
Judware, R; Culp, L A (1997) N-myc over-expression downregulates alpha3beta1 integrin expression in human Saos-2 osteosarcoma cells. Clin Exp Metastasis 15:228-38
Judware, R; Culp, L A (1997) Concomitant down-regulation of expression of integrin subunits by N-myc in human neuroblastoma cells: differential regulation of alpha2, alpha3 and beta1. Oncogene 14:1341-50
Judware, R; Culp, L A (1995) Over-expression of transfected N-myc oncogene in human SKNSH neuroblastoma cells down-regulates expression of beta 1 integrin subunit. Oncogene 11:2599-607
Judware, R; Lechner, R; Culp, L A (1995) Inverse expressions of the N-myc oncogene and beta 1 integrin in human neuroblastoma: relationships to disease progression in a nude mouse model system. Clin Exp Metastasis 13:123-33
Flickinger, K S; Judware, R; Lechner, R et al. (1994) Integrin expression in human neuroblastoma cells with or without N-myc amplification and in ectopic/orthotopic nude mouse tumors. Exp Cell Res 213:156-63
Kleinman, N R; Lewandowska, K; Culp, L A (1994) Tumour progression of human neuroblastoma cells tagged with a lacZ marker gene: earliest events at ectopic injection sites. Br J Cancer 69:670-9
Lewandowska, K; Pergament, E; Sukenik, C N et al. (1992) Cell-type-specific adhesion mechanisms mediated by fibronectin adsorbed to chemically derivatized substrata. J Biomed Mater Res 26:1343-63

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