The effects of γ-interferon (γ-IFN) on the growth, morphology, and phenotypic expression of the human neuroblastoma (NB) cell line, LAN-1, have been extensively tested. Low doses of γ-IFN allowing more than 90% cell viability induce morphological differentiation and growth inhibition. Cells exposed to γ-IFN significantly decreased their growth rate, became smaller and poligonal, and sprouted long cellular processes with varicosities along their course, typical of the neurites seen in differentiated NB cells; morphological changes appeared within 48 h of culture with 1000 U/ml γ-IFN. The new morphological aspect reached the maximum expression after 6 days of culture, becoming more evident when fresh drug was added after 2 days of culture. A decrease in [3H]thymidine incorporation was also observed within 24 h; cell growth was completely inhibited at the 6th day. Membrane immunofluorescence showed several changes in NB-specific antigen expression after 6 days of treatment with γ-IFN. At the same time γ-IFN also modulated cytoskeletal proteins. These findings suggest that noncytotoxic doses of γ-IFN do promote the differentiation of LAN-1 neuroblastoma cells which is associated with the reduced expression of the malignant phenotype.
ASJC Scopus subject areas
- Cell Biology