Stimulation of anchorage-independent cell growth by endothelin in NRK 49F cells.
Endothelin (ET) is a vasoconstrictor peptide originally isolated from vascular endothelial cells. Recent studies have revealed that ET has many biological functions including growth factor-like activity. The present study aims to clarify whether ET-1 possesses the ability to stimulate anchorage-independent cellular growth, an indicator of factors with transforming activity. We found that NRK 49F cells possess a large number of high-affinity ET-1 receptors; labeled 125I-ET-1 binding was displaced by unlabeled ET-2 in a similar dose response, but in the case of ET-3, 100-fold more was required. Specific 125I-ET-3 binding was undetectable in NRK 49F cells, indicating that ET receptors in NRK 49F cells are ET-1/ET-2 selective. NRK 49F is a cell line which is most commonly used to assay for anchorage-independent cellular growth. Therefore, we explored whether ETs promote anchorage-independent cellular growth in this cell line. ET-1 and ET-2 stimulated NRK colony formation dose dependently in the presence of 1 nM epidermal growth factor (EGF). In contrast, ET-3 did not have colony-stimulating ability. In the presence of EGF, the maximal effect of ET-1 was approximately 90% of that of transforming growth factor-beta. Moreover, in the presence of maximal stimulating concentrations of EGF and transforming growth factor-beta, ET-1 additionally induced colony formation. These results indicate that ET-1 and -2 possess transforming growth factor-like activity for NRK 49F cells. Since ET-1 and -2 increased intracellular calcium levels, this ion may participate in signal transduction pathways by which ET-1 and -2 promote colony formation.
Kusuhara
M
M
Growth Factor Division, National Cancer Center Research Institute, Tokyo, Japan.
Yamaguchi
K
K
Kuranami
M
M
Suzaki
A
A
Ishikawa
S
S
Moon
H
H
Adachi
I
I
Hori
S
S
Handa
S
S
D000818:Animals; D002448:Cell Adhesion; D002455:Cell Division / Q000187:drug effects*; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000494:pharmacology; D016232:Endothelins / Q000378:metabolism / Q000494:pharmacology*; D004815:Epidermal Growth Factor / Q000494:pharmacology; D007668:Kidney; D007700:Kinetics; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism; D017466:Receptors, Endothelin; D011994:Recombinant Proteins / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000494:pharmacology
D016232:Endothelins; D011956:Receptors, Cell Surface; D017466:Receptors, Endothelin; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D004533:Egtazic Acid; D004815:Epidermal Growth Factor