The Effects of Adverse Growth Conditions on the Shedding of Carcinoembryonic Antigen from Cultured LS180 Colon Cancer Cells

Abstract

The synthesis and release of the tumor marker carcinoembryonic antigen (CEA) from the colon cancer cell line LS180 has previously been reported to be enhanced during the later stages of in vitro culture after growth has stopped. It has been suggested that CEA expression was inversely related to the growth rate for these cells (Kahan, B.D.; Rutzky, L.P.; Legrue, S.J.; Tom, B.H. Methods Cancer Res. 18:197-275; 1979 and Shi, Z.R.; Tsao, D.; Kim, Y.S. Cancer Res. 43:4045-4049; 1983). Our studies indicate, however, that while certain environmental perturbations that halt growth (e.g., glucose starvation and elevated temperatures) do indeed stimulate CEA expression and release; other growth-arresting conditions, such as oxygen starvation, have no effect. Replacement of spent or conditioned medium with fresh medium during the later culture stages resulted in a 10-fold decrease in CEA release, indicating that either depleted nutrients or accumulating cellular products (such as lactate or ammonium) trigger enhanced CEA production.