Differential expression of the intercellular adhesion molecule-1 (ICAM-1) in lung cancer cell lines of various histological types.

Ten small cell lung carcinoma and 12 non-small cell lung carcinoma cell lines of various histological types were studied for constitutive expression of the intercellular adhesion molecule-1 (ICAM-1). ICAM-1 was present in all squamous and large cell carcinoma cell lines whereas two out of five adenocarcinoma and all small cell lung cancer (SCLC) cell lines showed no basal ICAM-1 expression. ICAM-1 expression was upregulated by tumour necrosis factor-alpha (TNF-alpha) in a time- and dose-dependent manner in cell lines with basal ICAM-1 expression. Western blot analysis revealed a molecular size of 85 kDa for ICAM-1 in all but one cell line. The TNF-alpha-induced upregulation of ICAM-1 occurs on the transcriptional level. Adhesion of peripheral blood mononuclear cells to lung tumour cell lines could be inhibited by monoclonal antibodies (MAb) (CD11a;CD18) against the receptor of ICAM-1, the leukocyte function-associated antigen-1 (LFA-1), but not by a MAb (CD54) against ICAM-1 itself.