EXPRESSION OF ACINAR END DUCTAL PRODUCTS IN CAPAN-1 CELLS GROWING IN SYNTHETIC SERUM AND SERUM-FREE MEDIA

Background. 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 reg arding the actual cell of origin for these exocrine carcinomas. Two ac inar antigens, ribonuclease and trypsin, were analyzed in cells growin g in synthetic serum. Methods. Capan-1 cells were adapted to grow in b asal medium supplemented with synthetic serum, because fetal bovine se rum (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, a llowing 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 Nort hern blot analysis. Results. Capan-1, PANC-1, IBF-CP3, and MDAAmp-7 ce ll lines were successfully adapted to grow in synthetic serum by means of the adaptation protocol reported here. The adaptation of Capan-1 t o serum-free media showed that the cells are capable of growing in a m edium containing insulin, transferrin, selenium, a nonprotein carrier, and lipoic and linoleic acids. Northern blot analysis showed the expr ession of carbonic anhydrase II, cytokeratin 18, ribonuclease, and try psin in Capan-1 cells growing in FBS and synthetic serum. No changes i n morphology, karyotype, or gene expression were observed in these cel ls as a result of the adaptation process. Conclusion. The cell line Ca pan-1 is expressing some ductal as well as acinar products despite its supposed ductal origin. The expression of trypsin at the mRNA level a nd ribonuclease at mRNA and protein levels is shown in Capan-1 cells. The protein expression will be further investigated as the cell line h as been adapted to grow in synthetic serum and serum-free media with n o apparent changes with respect to their growth in FBS.