Syalil-SSEA1(SLX) levels in supernatant of cultured human lung carcinoma cell lines.

Abstract

SLX levels in the culture supernatant of the following 50 cell lines were measured by RIA: pulmonary carcinoma cell lines derived from 46 patients, cell lines of other human cancers derived from 4 patients, and 2 passaged human fibroblast cells as control. Of the 46 pulmonary carcinoma cell lines, 17 (37%) were SLX positive. When the SLX-positive rate was analyzed in relation to the histological type of pulmonary carcinoma, the positive rate was 71% (10/14) for adenocarcinoma, 27% (3/11) for squamous cell carcinoma, 33% (2/6) for large cell carcinoma, 0% (0/11) for small cell carcinoma and 50% (2/4) for adenosquamous cell carcinoma. Analysis of the relationship between tumor cell proliferation and SLX level in 20 patients revealed that the SLX level in the supernatant of SLX-producing cell lines becomes higher in proportion to the increase in the number of these cells. The SLX-positive rate did not differ significantly among different stages of pulmonary carcinoma at the time of tissue collection. There was no significant correlation between SLX production and prognosis. SLX production by each cell line was not correlated with the doubling time of the same cell line in vitro or in vivo (in nude mice). SLX production also showed no correlation with the duration of tumor cell passage.