IFN-gamma-induced change in microtubule organization and alpha-tubulin expression during growth inhibition of lung squamous carcinoma cells.
In cultures of KNS-62 cells derived from a human lung squamous cell carcinoma, the initial growth arrest in the continuous presence of interferon-gamma (IFN-gamma) turned to cytopathic effects after 2 days of treatment. The remaining viable cells showed grossly distorted morphology, with enlargement and extensions up to 5 cell diameters. The presence of apoptotic cells was shown 3 days after treatment with IFN-gamma. Immunocytochemically, the microtubular structures appeared augmented and highly aggregated. The level of alpha-tubulin-specific mRNA was distinctly increased after administration of IFN-gamma, and the amount of extractable alpha-tubulin protein was reduced. In parallel kinetics experiments, growth arrest by serum depletion or by contact inhibition during confluence resulted in reduced levels of alpha-tubulin-specific mRNA and in slightly elevated alpha-tubulin protein. The IFN-gamma-induced effects suggest interference with assembly or maintenance of the tubulin cable network, presumably associated with cell deformation and cytotoxicity.
Everding
B
B
Department of Internal Medicine, University Hospital Eppendorf, Hamburg, Germany.
Wilhelm
S
S
Averesch
S
S
Scherdin
U
U
Hölzel
F
F
Steffen
M
M
D017209:Apoptosis; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D002455:Cell Division; D003260:Contact Inhibition; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D006801:Humans; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000494:pharmacology*; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008870:Microtubules / Q000276:immunology / Q000648:ultrastructure*; D012333:RNA, Messenger / Q000096:biosynthesis; D014404:Tubulin / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D016895:Culture Media, Serum-Free; D012333:RNA, Messenger; D014404:Tubulin; D007371:Interferon-gamma