Three‐dimensional Reorganization of a Cell Line of Papilla Vateri Adenocarcinoma in Various Culture Conditions

SAV‐I, a cell line derived from a well differentiated adenocarcinoma of Vater's papilla, was cultured under four different conditions using collagen gel matrices (type I collagen): 1) double‐layered, 2) floating double‐layered, 3) embedded, and 4) floating embedded, then observed by light and electron microscopy and immunohistochemistry. Under all four conditions, three‐dimensional growth with tubules occurred. In particular, the floating double‐layered condition, where the cells were cultured between two collagen gel layers, then floated onto the medium, was useful for showing cellular reorganization. The three‐dimensional growth patterns observed in vitro closely resembled the in vivo growth of SAV I cells transplanted into nude mice. Therefore, we conclude that the floating double‐layered condition is useful for demonstrating the morphological characteristics of the parent cells of established cell lines, and should be advantageous for studies of the relationship between cellular morphology and function in vitro.