Reversible structural alterations of undifferentiated and differentiated human neuroblastoma cells induced by phorbol ester.

AUTOR(ES)

Tint, I S

RESUMO

Morphological alterations in the structure of undifferentiated and morphologically differentiated human neuroblastoma cells induced by phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C, were examined by video microscopy and immunomorphology. In undifferentiated cells, PMA induced the formation of motile actin-rich lamellas and of stable cylindrical processes rich in microtubules. Formation of stable processes resulted either from the collapse of lamellas or the movement of the cell body away from the base of a process. In differentiated cells, PMA induced the rapid extension of small lamellas and subsequent formation of short-lived elongated processes from the lateral edges of neurites. Additionally, growth cones exhibited enhanced modulation in shape after PMA treatment. These reversible reorganizations were similar to the actinoplast-tubuloplast transformations exhibited by PMA-treated fibroblasts. We suggest that actinoplast-tubuloplast reorganizations play essential roles in morphogenesis where stable cytoplasmic extensions are induced by external stimuli. In particular, PMA-induced reorganizations of neural cells in culture may be a model for morphological modulations that occur in nerve tissue.

Documentos Relacionados

• Modulation of secretory leukoprotease inhibitor gene expression in human bronchial epithelial cells by phorbol ester.
• Transient expression of foreign genes in lymphoid cells is enhanced by phorbol ester.
• Association of phorbol ester-induced hyperphosphorylation and reversible regulation of transferrin membrane receptors in HL60 cells.
• Activation of S6 kinase activity in 3T3-L1 cells by insulin and phorbol ester.
• Voltage-gated potassium conductance in human T lymphocytes stimulated with phorbol ester.