Characterization of the progressive sublines derived from a weakly malignant cloned cell line, ER-1, co-inoculated subcutaneously with a foreign body.
We previously established an experimental model of tumor progression using a weakly malignant rat mammary carcinoma cell line, ER-1. Using this model, we demonstrated that ER-1 cells converted into highly tumorigenic and metastatic cells, ERpP, by s.c. co-inoculation with plastic plates. We here compared in vitro biological properties associated with malignancy of ER-1 cells with those of ERpP cells which were highly malignant when inoculated into syngeneic rats. In vitro growth rate of ERpP cells was higher than that of ER-1 cells under a low nutrient condition. Invasion capacity of ERpP cells to rat lung endothelial cell monolayer or reconstituted basement membrane, Matrigel, was higher than that of ER-1 cells. Migration of ERpP cells toward fibronectin or laminin was also significantly higher than that of ER-1 cells. There was no difference in gelatinolytic or plasminogen activator activity detected in conditioned media between ER-1 and ERpP cells. Furthermore, we found that ER-1 cells communicated better among themselves and with normal fibroblasts through gap junctions compared to ERpP cells. These results suggest that growth advantage in a poor nutrient condition, enhancement of cell motility, and loss or decrease of junctional communication may be associated with tumor progression of ER-1 cells.
Hamada
J
J
Division of Cell Biology, Cancer Institute, Hokkaido University School of Medicine, Sapporo, Japan.
Nagayasu
H
H
Kawano
T
T
Mizutani
T
T
Nakata
D
D
Hosokawa
M
M
Takeichi
N
N
D000818:Animals; D002450:Cell Communication; D002455:Cell Division; D002633:Chemotaxis; D003094:Collagen; D004338:Drug Combinations; D004730:Endothelium, Vascular / Q000166:cytology; D005353:Fibronectins; D018093:Gelatinases / Q000378:metabolism; D007365:Intercellular Junctions; D007797:Laminin; D008325:Mammary Neoplasms, Experimental / Q000473:pathology*; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D010960:Plasminogen Activators / Q000378:metabolism; D011509:Proteoglycans; D051381:Rats; D014407:Tumor Cells, Cultured
D004338:Drug Combinations; D005353:Fibronectins; D007797:Laminin; D011509:Proteoglycans; C059485:matrigel; D003094:Collagen; D010960:Plasminogen Activators; D018093:Gelatinases