In vitro models of human colonic adenomatous polyps.

In this report we describe methods which were used to cultivate cell lines from adenomatous polyps. Many of the techniques used have evolved from our past experience with the cultivation of colonic epithelial neoplastic cells (McBain et al., 1984) and the experience of others successful in the cultivation of benign and cancerous colon tissues. We feel that the preservation of cell-to-cell associations is a key to our successful cultivation of adenomas. Moyer (Moyer and Aust, 1984) has also pointed out the importance of preserving cell-to-cell associations in her successful studies to culture normal and neoplastic colonic tissues. Friedman's primary culture system for adenomatous polyps (Friedman et al., 1981) is further evidence supporting this point. Using the techniques described in this report, three cell lines, two small tubular polyps and one villous polyp, have been established and characterized. These cells can be expanded to numbers that will be sufficient for molecular and biochemical studies, and the cell number will be sufficient to conduct transfection experiments. Paraskeva (Paraskeva et al., 1984) has described two other cell lines derived from adenomatous polyps arising in patients with familial polyposis. The availability of cell lines from tubular and villous polyps make it possible to propose experiments to probe the biology of colonic adenomas.

Cell culture of human colon adenomas and carcinomas.

Cell lines were established from colon adenomas, including tubular and villous polyps, primary adenocarcinomas, and metastases arising in patients with colon adenocarcinomas. The protocol for cultivating these diverse tissues includes primary cultivation of tissue explants on a type I collagen gel followed by nonenzymatic subculture of the epithelial outgrowth. All early passages were accomplished using low subculture ratios. Cultured cells elaborate morphological structures which are similar to features present in the tissues from which they were cultivated. Specifically, all structural features of colon epithelial cells were identified, including junction formation, prominent microvilli, and mucin secretion, in several cell lines. Five cell lines cultured from colonic neoplasms at different stages of cancer progression were selected for detailed characterization. Cells grown from two tubular polyps had normal human karyotypes. Cells from a villous polyp and all adenocarcinomas were aneuploid with stable marker chromosomes. The established cell lines exhibit distinct phenotypes based on growth characteristics in vitro and in athymic mice; and it is suggested that these cell lines represent useful models for studying the evolution of colon cancer from a benign to an aggressive cell type.