Dome formation by a human colonic adenocarcinoma cell line (HCA-7)

A new cell line, HCA-7, has been established from a primary human colonic adenocarcinoma. The HCA-7 cells have an epithelial morphology by phase-contrast microscopy, they secrete carcinoembryonic antigen, and they form adenocarcinomas when injected s.c. into nude mice. HCA-7 cells retain some of the morphological and functional polarity exhibited by normal colonic epithelium. Cells form a polarized epithelial sheet when grown on tissue culture plastic in standard culture medium (Dulbecco's modification of Eagle's medium with 10% fetal calf serum). The cells were shown to be structurally polarized with sparse microvilli present at the apical surface but absent from the basolateral surface. Cells were connected by apical tight junctions and frequent desmosomes. Confluent monolayers of HCA-7 cells formed "domes" or "hemicysts" due to vectorial fluid transport resulting in fluid accumulation in localized areas of the monolayer. HCA-7 cells will provide a useful system for studying the role of hormones and other factors in the control of transepithelial transport and maintenance of cell polarity.