Caco-2 세포의 분화에 따른 세포사멸 감수성의 변화

Abstract

Background/Aims: The balance between proliferation and apoptosis is important for homeostasis during differentiation in crypt-villus axis of intestinal epithelium. In addition, cellular responses to diverse stimuli also vary by the degree of cellular differentiation. We investigated the differences in apoptotic sensitivities in genotoxin- and indomethacin-induced apoptosis, based on the degree of differentiation of epithelial cells. Methods: Differentiation was induced by post-confluence culture or treatment of sodium butyrate in Caco-2 cells. Indomethacin, VP-16 and MMS (methyl methanesulfonate), which is a direct-acting DNA alkylating agent, were used for apoptosis induction. Degree of differentiation was measured by alkaline phosphatase activity assay. The apoptotic cell death was measured by MTT assay and flow cytometry. Results: Compared to the subconfluent Caco-2 cells, both 7 days post-confluent cells and sodium butyrate-treated cells showed significantly increased alkaline phosphatase activity. Both post-confluence- and butyrate-induced differentiated cells showed increased resistance to MMS- or VP-16-induced apoptosis. While post-confluence-induced differentiated cells showed increased resistance to indomethacin-induced apoptosis, butyrate-induced differentiated cells showed increased sensitivity to indomethacin-induced apoptosis. Conclusions: Our data demonstrate that differentiated Caco-2 cells induced resistance to genotoxin- and indomethacin- induced apoptosis, although indomethacin-induced apoptosis was increased in butyrate-induced differentiated Caco-2 cells.