Expression of acinar and ductal products in Capan-1 cells growing in synthetic serum and serum-free media.

Abstract

Capan-1 is a human pancreatic adenocarcinoma cell line of presumed ductal origin. This is based on the histologic appearance of the tumor from which it arose. Yet considerable controversy exists regarding the actual cell of origin for these exocrine carcinomas. Two acinar antigens, ribonuclease and trypsin, were analyzed in cells growing in synthetic serum. Capan-1 cells were adapted to grow in basal medium supplemented with synthetic serum, because fetal bovine serum (FBS) normally used to culture cells contains bovine ribonuclease, which can interfere with measurements of the ribonuclease secretion. These cells were also adapted to grow in different serum-free media, allowing us to determine its minimal growth requirements. The presence of ribonuclease in Capan-1 and PANC-1 conditioned media was monitored by activity. Other acinar and ductal markers were monitored using Northern blot analysis. Capan-1, PANC-1, IBF-CP3, and MDAAmp-7 cell lines were successfully adapted to grow in synthetic serum by means of the adaptation protocol reported here. The adaptation of Capan-1 to serum-free media showed that the cells are capable of growing in a medium containing insulin, transferrin, selenium, a nonprotein carrier, and lipoic and linoleic acids. Northern blot analysis showed the expression of carbonic anhydrase II, cytokeratin 18, ribonuclease, and trypsin in Capan-1 cells growing in FBS and synthetic serum. No changes in morphology, karyotype, or gene expression were observed in these cells as a result of the adaptation process. The cell line Capan-1 is expressing some ductal as well as acinar products despite its supposed ductal origin. The expression of trypsin at the mRNA level and ribonuclease at mRNA and protein levels is shown in Capan-1 cells. The protein expression will be further investigated as the cell line has been adapted to grow in synthetic serum and serum-free media with no apparent changes with respect to their growth in FBS.