Expression of intercellular adhesion molecule-1 is regulated by the actin network in epidermoid carcinoma cells

Expression of the cell surface protein intercellular adhesion molecule-1 (ICAM-1) is a prerequisite for the interaction of a large variety of cells with leukocytes. Constitutive expression of ICAM-1 in human epidermoid carcinoma cells is low, but is inducible through inflammatory cytokines including interferon gamma (INF gamma). Disruption of the actin cytoskeleton with dehydrocytochalasin B (CB) increased constitutive and potentiated INF gamma-induced ICAM-1 cell surface expression, but did not alter formation of soluble ICAM-1. Actinomycin D inhibited CB-induced ICAM-1 surface expression and CB increased the steady-state levels of ICAM-1 transcripts. However, CB did not alter the glyceralaldehyde-3-phosphate dehydrogenase mRNA levels and the ICAM-1 mRNA half-life. These studies indicate that in human epidermoid carcinoma cells the actin cytoskeleton regulates ICAM-1 transcription and cell surface expression.