Characterization of cancer cell dissociation factor in a highly invasive pancreatic cancer cell line.
BACKGROUND
Two pancreatic cancer cell lines, the highly invasive and metastatic cell line PC-1.0 and the weakly invasive and rarely metastatic cell line PC-1, were established from a pancreatic ductal carcinoma induced by N-nitrosobis (2-oxopropyl) amine in a Syrian golden hamster.


METHODS
The cancer cell dissociation activity in serum-free conditioned medium of PC-1.0 cells was partially purified using a heparin column, a hydroxylapatite column, anion exchange, and gel filtration high-performance liquid chromatography. Several biologic properties of the partially purified activity were evaluated.


RESULTS
Two cell lines exhibited different growth morphologic changes in vitro: the weakly invasive cell line PC-1 formed islandlike colonies, and the highly invasive cell line PC-1.0 grew mainly as single cells. The conditioned medium of PC-1.0 cells induced dissociation of islandlike colonies and morphologic changes of PC-1 cells to elongated cells, with a high frequency of pseudopodia formation similar to the morphologic findings of PC-1.0 cells. The dissociation activity did not bind to the heparin column and had an apparent molecular mass of > 400 kDa, as deduced from gel filtration. Several immunoreactive proteinous bands were observed in immunoblotting analysis using a polyclonal blocking antibody. The partially purified activity enhanced cell motility, chemoinvasion, and cell adhesion to plastic plates and fibronectin.


CONCLUSIONS
Highly invasive and metastatic PC-1.0 cells produce a soluble proteinous factor, called "dissociation factor" (DF), which induces cell dissociation of weakly invasive and rarely metastatic PC-1 cells. It seems likely that DF has a role in tumor invasion and metastasis.
Kurizaki
T
T
Department of Surgery II, Kumamoto University Medical School, Japan.
Egami
H
H
Hirota
M
M
Akagi
J
J
Ohmachi
H
H
Yamamoto
S
S
Ogawa
M
M
D000230:Adenocarcinoma / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D002448:Cell Adhesion; D002465:Cell Movement; D006224:Cricetinae; D017077:Culture Media, Conditioned; D004591:Electrophoresis, Polyacrylamide Gel; D015151:Immunoblotting; D008647:Mesocricetus; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000737:chemistry*; D010190:Pancreatic Neoplasms / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D014407:Tumor Cells, Cultured
D017077:Culture Media, Conditioned; D009363:Neoplasm Proteins