Abstract
A stable and efficient system for the culture of murine colon epithelial cells or crypts is required to facilitate studies of the dynamics and factors affecting colon stem cell niche and crypt formation. Survival of colonic epithelial cells or crypts in vitro was not established until recently, when it was found that exogenous Wnt3A and R-spondin could promote cell survival and formation of spheroids (colonospheres) or some advanced organoids with well-developed crypts (colonoids). However, after 6-8 days in these culture conditions, only small numbers of colonospheres form organoids with crypt-like structures (colonoids). This study describes the use of a myofibroblast cell line and a coculture system that increases the efficiency of colonoid formation from isolated crypts. The enhanced coculture system has significantly improved colonoid-forming efficiency compared with results from previous systems. Crypt formation can be detected as early as day 2. The coculture system will facilitate the characterization of the colon stem cell niche and the changes that occur as a result of perturbations or mutations in colon stem or epithelial cells, such as those that favor precancerous adenoma or cancer.