Correlation between tumor proliferation and tumor tissue level of urokinase-type plasminogen activator.
We established a xenotransplanted human colon cancer strain, TK-3, which produces urokinase-type plasminogen activator (U-PA) and carcinoembryonic antigen (CEA) simultaneously. Immunohistochemical staining of U-PA revealed that U-PA was located in the cytoplasm of cancer cells. Using TK-3, we investigated whether the tissue level of U-PA changed when the tumor proliferated locally. The mice were divided into three groups: mice of group A, B and C were sacrificed at 4, 5 and 6 weeks after tumor inoculation, respectively. The tissue level of U-PA was 0.78 +/- 0.183 ng/mg protein in group A, 0.95 +/- 0.189 in group B and 1.13 +/- 0.311 in group C. The values of groups B and C increased significantly compared with those of group A, and the tumor weight in each group showed a similar increase. The level of plasminogen activator inhibitor type 2 also increased (0.14 +/- 0.078 ng/mg protein in group A, 0.17 +/- 0.096 in group B, 0.24 +/- 0.172 in group C). On the other hand, the tissue level of CEA did not change significantly (78 micrograms/g tissue in group A, 88 in group B, 76 tissue in group C), and no correlation was observed between the tissue levels of U-PA and CEA. These results suggest that U-PA plays an important role not only in metastasis, but also in local tumor proliferation, and that its biological action in the autocrine system is independent of CEA.
Konno
H
H
Second Department of Surgery, Hamamatsu University School of Medicine, Japan.
Tanaka
T
T
Maruo
Y
Y
Nishino
N
N
Nakamura
S
S
Baba
S
S
Takada
A
A
D000818:Animals; D002272:Carcinoembryonic Antigen / Q000032:analysis; D002455:Cell Division; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008875:Middle Aged; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000201:enzymology / Q000473:pathology*; D014183:Transplantation, Heterologous; D014568:Urokinase-Type Plasminogen Activator / Q000032:analysis*
D002272:Carcinoembryonic Antigen; D014568:Urokinase-Type Plasminogen Activator