Microtubules regulate expression of ICAM-1 in epidermoid cells (KB cells)

The intercellular adhesion molecule-1/CD54 (ICAM-1) functions as a counterreceptor for other adhesion molecules (e.g. the lymphocyte function-associated antigen-1/CD11a/CD18) required for the interaction of a large variety of cells with leucocytes. Constitutive expression of ICAM-1 in human epidermoid cells (KB cells) is low, but inducible by interferon-gamma (IFN-gamma). Treatment of KB cells with microtubule-disrupting agents, like colchicine, nocodazole and vinblastine, potentiated the constitutive and cytokine-induced ICAM-1 expression on the cell surface. Actinomycin D inhibited microtubule-disrupting agent-induced ICAM-1 surface expression. Increased steady-state levels of ICAM-1 transcripts were found after treatment of KB cells with microtubule-disrupting agents. However, microtubule-disrupting agents neither altered the glyceraldehyde-3-phosphate dehydrogenase mRNA levels nor the amount of expressed alpha(2)-, alpha(3)-and beta(1)-integrins at the cell surface. In addition, they did not change the ICAM-1 mRNA half-life. These studies indicate a control function of the microtubule network on the expression of ICAM-1.