Establishment and characterization of long-term primary mouse urothelial cell cultures.

Long-term mouse urothelial cell cultures were routinely established from explants of neonatal mouse bladders. Foci of proliferating cells could be observed one week after the initiation of the explant cultures. These persisted throughout the culture period and up to one year. Expression of keratin proteins confirmed the epithelial nature of the cultured cells. Morphologic analysis of nuclei sorted after DNA flow cytometry revealed a population of DNA-tetraploid and octoploid cells with large nuclei and prominent nucleoli in addition to a DNA-diploid cell population. Both cell populations showed DNA replicative activity as reflected by bromodeoxyuridine incorporation studies and mitotic activity. These long-term primary mouse urothelial cell cultures may prove useful for studies on urothelial cell kinetics and bladder carcinogenesis.