The role of integrins and extracellular matrix in anchorage-independent growth of a mammary carcinoma cell line.
Anchorage-independent growth is a property of malignant cells. Extracellular matrix proteins are present in tumor spheroids but their function is not clearly defined. In this paper we show that a murine mammary carcinoma cell line, SP1, which expresses the fibronectin receptor alpha 5 beta 1 requires fibronectin for anchorage-independent growth in soft agar. Growth factors (hepatocyte growth factor and transforming growth factor-beta) also promote SP1 colony growth. In contrast, collagen types I and IV have an inhibitory effect on SP1 colony growth. A clone isolated from SP1 cells which expresses the collagen/laminin receptor alpha 2 beta 1 as well as the fibronectin receptor alpha 5 beta 1, demonstrates increased colony formation in the presence of fibronectin and collagen. These data suggest a role for both the alpha 5 beta 1 and alpha 2 beta 1 integrin receptors in the regulation of anchorage-independent growth of mammary carcinoma cells.
Saulnier
R
R
Department of Pathology, Queen's University, Kingston, ON, Canada.
Chan
B
B
Uniyal
S
S
Chan
T
T
Patrzykat
A
A
Elliott
B E
BE
D000818:Animals; D002448:Cell Adhesion; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D003094:Collagen / Q000494:pharmacology; D005109:Extracellular Matrix / Q000502:physiology*; D005260:Female; D005353:Fibronectins / Q000494:pharmacology; D017228:Hepatocyte Growth Factor / Q000494:pharmacology; D016023:Integrins / Q000502:physiology*; D008325:Mammary Neoplasms, Experimental / Q000473:pathology*; D051379:Mice; D038981:Receptors, Collagen; D017469:Receptors, Fibronectin / Q000502:physiology; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D005353:Fibronectins; D016023:Integrins; D038981:Receptors, Collagen; D017469:Receptors, Fibronectin; D016212:Transforming Growth Factor beta; D017228:Hepatocyte Growth Factor; D003094:Collagen