In vitro pancreatic ductal cell carcinogenesis.
Our experiments were designed to identify initial biochemical and biological changes that occur during pancreatic carcinogenesis. TAKA-1, an immortal hamster pancreatic ductal cell line, was treated in vitro for up to 11 weeks with the pancreatic carcinogen N-nitorosobis(2-oxopropyl)amine (BOP). These treated cells were designated TAKA-1 + BOP. The growth of TAKA-1 and TAKA-1 + BOP cell lines was investigated in soft agar and in hamsters intradermally. The resulting tumor from TAKA-1 + BOP was re-cultured in vitro and designated TAKA-1 + BOP-T. Mutation of c-K-ras and p53 oncogenes, chromosomal changes, expression of transforming growth factor alpha (TGF-alpha) and epidermal growth factor (EGF) receptor and several biochemical markers were examined in all cell lines. TAKA-1 + BOP but not TAKA-1 cells grew in soft agar and produced an invasive tumor in vivo. However, there were no differences in cell growth rate, DNA flow cytometry, or immunohistochemical findings between the non-transformed and transformed cells. TAKA-1, TAKA-1 + BOP and TAKA-1 + BOP-T cells all expressed mRNA of TGF-alpha and EGF receptor in a comparable pattern. DNA sequence analysis following polymerase chain reaction showed that neither TAKA-1 nor TAKA-1 + BOP cells has a mutation of c-K-ras or p53. Karyotype analysis demonstrated that TAKA-1 + BOP cells had more chromosomal abnormalities compared with TAKA-1 cells. Mutation of c-K-ras and p53 was not essential for carcinogenesis in hamster pancreatic ductal cells in vitro. In conclusion, immortality of the TAKA-1 cells caused expression of TGF-alpha to the same extent as in malignant cells. Chromosomal and ultrastructural patterns were the only differences detected between the non-transformed and BOP-transformed cells.
Ikematsu
Y
Y
The Eppley Institute for Research in Cancer, University of Nebraska Medical Center, Omaha 68198-6805, USA.
Liu
G
G
Fienhold
M A
MA
Cano
M
M
Adrian
T E
TE
Hollingsworth
M A
MA
Williamson
J E
JE
Sanger
W
W
Tomioka
T
T
Pour
P M
PM
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002273:Carcinogens; D002455:Cell Division; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D006224:Cricetinae; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D016158:Genes, p53; D011905:Genes, ras; D007621:Karyotyping; D007633:Keratins / Q000032:analysis; D007700:Kinetics; D051379:Mice; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009602:Nitrosamines; D010183:Pancreatic Ducts / Q000166:cytology* / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000648:ultrastructure; D051381:Rats; D016415:Sequence Alignment; D016211:Transforming Growth Factor alpha / Q000096:biosynthesis
D002273:Carcinogens; D009602:Nitrosamines; D016211:Transforming Growth Factor alpha; C013622:nitrosobis(2-oxopropyl)amine; D004815:Epidermal Growth Factor; D007633:Keratins; D066246:ErbB Receptors