[Characterization of tumor cell growth inhibitor present in rabbit serum].
Growth inhibitors present in various kinds of sera were surveyed using the rat liver epithelial cell line BRL and its tumorigenic transformant RSV-BRL as indicator cells. This survey revealed that normal rabbit serum contained two types of growth inhibitors: one (GI-A) was more growth-inhibitory on RSV-BRL than BRL, whereas the other (GI-B) vice versa. GI-A was purified 3,000-fold to show a major protein band with Mr 70k on SDS-PAGE. It was an acid-and heat-labile protein and potently inhibited the growth of three kinds of transformed cell lines and two human carcinoma cell lines, but hardly that of non-transformed cell lines, at a dose of 0.5-1.0 micrograms/ml. On the other hand, GI-B was an acid- and heat-stable protein with Mr 25k and was considered to belong to the TGF-beta family.
Miyazaki
K
K
Division of Cell Biology, Kihara Institute for Biological Research, Yokohama City University, Japan.
Kimura
T
T
Kakuno
T
T
D000818:Animals; D002277:Carcinoma / Q000473:pathology*; D002461:Cell Line, Transformed; D006131:Growth Inhibitors / Q000097:blood / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D008970:Molecular Weight; D011817:Rabbits / Q000097:blood*; D051381:Rats
D006131:Growth Inhibitors