Expression of Oncodevelopmental Gene Products by Human Tumor Cells in Culture2

Abstract

Sixty-seven human tumor cell lines and 15 lines derived from normal tissue were examined for the production of the oncodevelopmental markers carcinoembryonic antigen, alpha and beta subunits of chorionic gonadotropin, placental and nonplacental forms of alkaline phosphatase, γ-glutamyltransferase, cystyl aminopeptidase, and calcitonin. Both intracellular and extracellular levels of these markers were determined at three phases during the growth of each culture. Sixty-eight percent of the cell lines produced elevated levels (≥90th percentile) of at least one marker. Of those, 46% produced elevated levels of one marker only, 29% produced two, 22% produced three, and 4% produced four markers. No cell line produced more than four markers at elevated levels. In most instances, however, the expression of any two particular markers was discordant. For approximately 50% of the possible marker pairs, Spearman rank-ordered correlation analyses showed significant negative correlations, indicating that when one marker was produced at elevated levels by a given cell line, other markers were usually absent or produced at relatively low levels. In no instance was a significant positive correlation found between two markers. These data indicated that, although most human malignant cells examined produced one or more oncodevelopmental gene markers at elevated levels, no predictable coexpression of any two of the markers was seen.