Annals of Oncology 10:S41-S45, 1999
© 1999 European Society for Medical Oncology
In vitro pancreatic carcinogenesis
1 UNMC Eppley Cancer Center, The Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center Omaha, NE, U.S.A.
2 Department of Visceral and Transplantation Surgery, Insel Hospital Bern, Switzerland
3 Department of Surgery, Rheinische Friedrich-Willhelms-University Bonn, Germany
4 Department of Surgery II, Kumamoto University Kumamoto, Japan
5 Tangshan GongRen Hospital, Hebei Medical University China
6 Department of Pathology and Microbiology, University of Nebraska Medical Center Omaha, NE, U.S.A.
Correspondence to: Parviz M. Pour, M.D. UNMC/Eppley Cancer Center, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, Ne 68198-6805, U.S.A. E-mail: ppour{at}unmc.edu
Studies in our laboratories have indicated that pancreatic cancer originates not only from pancreatic ductal/ductular cells but also from within the Langerhans' islets, probably from reserve (precursor, stem) cells. To identify, enrich and characterize these cells, we established a long-term hamster islet culture and studied their growth, differentiation and response to the pancreatic carcinogen, N-nitrosobis(2-oxopropyl)amine (BOP). One group of cultured islets was treated in vitro with BOP (KL5B group) and the other group of islets served as an untreated control (KL5N group). During the early culture days, in both groups all cultured islets showed a progressive loss of endocrine cells and replacement by ductular, acinar and intermediary cells. However, all these cells disappeared after 35 days in culture and gave room to undifferentiated cells, which we believe represent stem cells. No differences were found between KL5N and KL5B cells with regard to cell growth and differentiation until day 35, when the growth of the KL5B cells accelerated and the cells underwent increasing pleomorphism and atypia. At day 133, KL5B cells but not KL5N cells showed colony formation in soft agar and formed invasive, poorly differentiated adenocarcinomas of the ductal type when transplanted into hamsters. All of these tumors showed mutation of the K-ras gene and extensive chromosomal damage. We concluded that like ductal/ductular cells, certain cell populations within islets are responsive to the carcinogenic effect of BOP. We could not ascertain whether these cells present a preexisting (stem, reserve) cell population within the islets or transdifferentiated islet cells.
carcinogenesis, culture, differentiation, hamster, islets, pancreas