NCAM: a surface marker for human small cell lung cancer cells

Immunocytochemical and immunochemical techniques were used to study
the expression of the neural cell adhesion molecule (NCAM) by human
lung cancer cell lines. Intense surface staining for NCAM was found
at light and electron microscopic levels on small cell lung cancer
cells. The NCAM polypeptide of Mr 140000 (NCAM 140) was detected by
immunoblotting in all of 7 small cell lung cancer cell lines
examined and in one out of two of the closely related large cell
cancer cell lines: it was not detected in cell lines obtained from
one patient with a mesothelioma, in two cases of adenocarcinoma,
nor in two cases of squamous cell cancer. In contrast,
neuron-specific enolase was found by immunoblotting in all the lung
cancer cell lines tested and synaptophysin in all but the
adenocarcinoma cell lines. These antigens were localized
intracellularly. The specific expression of NCAM 140 by human small
and large cell lung carcinomas suggests its potential as a
diagnostic marker.