Exogenous thrombospondin stimulates the proliferation of non-thrombospondin-producing cells.
The effects of thrombospondin (TSP) on the proliferation of two different human carcinoma cell lines (KIM-1 and CW-2) were investigated. The characterization of these two carcinoma cells by immunohistochemistry using anti-TSP antibody and anti-TSP-receptor antibody showed that the KIM-1 had TSP-receptors and TSP, while the CW-2 had only TSP-receptors. The addition of exogenous TSP (10 or 20 microg/ml) to culture medium stimulated the cell proliferation of CW-2 but not that of KIM-1. The cell count for CW-2 was increased dosage-dependently from 10.3 0.6x104/ml at zero TSP concentration to 12.9 0.6x104/ml at 10 microg/ml TSP concentration and to 14.7 0. 4x104/ml at 20 microg/ml TSP (each p<0.0001). In conclusion, though TSP promoted the proliferation of non-TSP-producing cells, it did not promote proliferation of TSP-producing cells. Therefore, it is predicted that TSP was already at saturated activity concentration in the TSP-producing cell line (KIM-1).
Second Department of Surgery, Fukuoka University School of Medicine, Jonan-ku, Fukuoka 814-0180, Japan.
Y
Y
Yamashita
S
S
Sendo
T
T
Hosokawa
G
G
Tuszynski
T
T
Kurohiji
R
R
Beppu
T
T
Shinohara
T
T
Kinugasa
T
T
Shirakusa
D015153:Blotting, Western; D018955:CD36 Antigens / Q000096:biosynthesis / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D002455:Cell Division / Q000187:drug effects; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D006801:Humans; D008027:Light; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D008853:Microscopy; D016253:Microscopy, Immunoelectron; D013268:Stimulation, Chemical; D019699:Thrombospondins / Q000096:biosynthesis / Q000494:pharmacology* / Q000502:physiology; D014407:Tumor Cells, Cultured / Q000187:drug effects
D018955:CD36 Antigens; D019699:Thrombospondins