Altered intermediate filament expression in human neuroblastoma cells transformed by a growth-promoting agent derived from schizophrenic CSF.

1. Transformed (TR) cell lines showed faster doubling times and higher cell densities at confluence, as well as altered morphology, changing from flat epitheloid to smaller round or bipolar shapes. Since such morphological changes are suggestive of alterations in intermediate filaments, we have analyzed the expression of both vimentin and neurofilament. 2. Immunohistochemical analysis of vimentin showed a redistribution from a cytoplasmic network to a perinuclear accumulation in TR cell lines. 3. Western blot analysis demonstrated that the vimentin content was decreased 60-90%. The content of the 70-kD neurofilament protein was also decreased in TR cells, but its intracellular distribution was indistinguishable from that in the control cell lines.