Nonadhesive organ culture of human exocrine pancreatic cells with their stroma.

Introduction: Studies using explanted tissue have shown that it is possible to keep adult human cells in organ culture with a preserved morphology for up to 1 month as spheres in a nonadhesive organ culture.

Aims: The current study was to determine whether human exocrine pancreatic cells also can be grown in this manner.

Methodology: Small tissue samples from organ donors and tumor-free resection rim from patients with pancreatic carcinoma were obtained (n = 16 adults). From each patient, fragments of approximately 300 microm in diameter were cultured and investigated with light microscopy and scanning and transmission electron microscopy at the time of explantation and after 5, 10, 20, 30, and 40 days of culture.

Results: Incubation of cultured fragments with vital dyes revealed a viable epithelium. At the time of explantation all the tissue fragments had a rough appearance with an uneven, torn periphery. During the first week of culture the fragments became rounder, with a smooth surface covering the whole circumference. This spheroid morphology persisted for the rest of the 6-week culture period. The fragments were within 1 week covered by a highly differentiated, polarized epithelium with secretory apparatus, apical secretion granules, and microvilli, as well as specialized cell junctions, with the same appearance as acinoductal pancreatic cells of the original tissue. The core of the fragments consisted of connective tissue with vascular elements, fibroblasts, leukocytes, and a few ductal and acinar elements. Transmission electron microscopy of the spheroids revealed a continuous basal lamina underneath the epithelium. Immunostaining for cytokeratin 5, 6, 7, 8, 17, and 18 was strongly positive in the epithelium.

Conclusion: These results show that normal exocrine pancreatic cells can be grown in vitro in a nonadhesive organ culture with their stroma.