New Method for Separation of Subpopulations from a Heterogeneous Colon Cancer Cell Line

Abstract

Background: To understand the heterogeneity of human colon cancers, a new method to separate cancer subpopulations was developed. Materials and Methods: Cells from a human colon cancer cell line, DLD-1, were seeded on an 8 μm pore membrane. After six hours, the cells which remained beneath the membrane as well as the cells which dropped onto the 24-well plate were collected. To clarify the differences between the two subpopulations, transepithelial electrical resistance (TEER) and immunocytochemistry were evaluated. Results: Two subpopulations, clones D and A, were separated from DLD-1 with the newly developed method. Both subpopulations showed quite different TEER values and different arrangements of cell-cell contact. In addition, the distinct subcellular localizations of claudin family proteins and zonula occludens-1 (ZO-1) were identified. Conclusion: A new separation method to isolate colon cancer subpopulations was established in which the intercellular junctions differed. This method can be considered as a helpful tool in the investigation of colon cancer heterogeneity.