ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
The mouse C3H teratoma-derived cell line 1246 is an adipogenic cell line which stringently requires insulin to proliferate and differentiate in defined medium. From this cell line an insulin-independent cell line celled 1246-3A was isolated. It was found that, in contrast to 1246 cells, 1246-3A cells had lost the ability to differentiate and became tumorigenic when injected at a density of 106 cells/mouse into syngeneic host C3H mice. In addition, they produce in their culture medium transforming growth factor (α)- and (β)-like polypeptides which stimulate their proliferation. Highly tumorigenic insulin-independent cell lines able to give rise to tumor when injected at a density of 104 cells/mouse were isolated by using. an in vitro-in vivo shuttle technique. The highly tumorigenic cell lines have lost the response to TGF-(β)1, The binding of TGF-(β)1, to the nontumorigenic parent cell line or to cells displaying increased tumorigenic properties was investigated. The data presented here indicate that the increased tumorigenicity is accompanied by a progressive decrease of specific binding of TGF-(β)1, to the cells. However, the decreased number of cell surface TGF-(β)1, binding sites in the highly tumorigenic cells did not correlate with an increase in the secretion of TGF-(β) protein by the tumorigenic cells, as all of TGF-(β) produced by the cells was in a latent form. Affinity cross-linking experiments indicated that the 1246 cell line displayed several TGF-(β) cross-linked molecular species (MW 140, 92, and 70 kDa). Increase of tumorigenicity was accompanied by a marked decrease in the intensity of the cross-linked bands, particularly of the 92 and 70 kDa species.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1041490321
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