The spermicidal surfactant nonoxynol-9 (Igepal CO-630, GAF Corp.) and a potential impurity, lP-dioxane, were tested in the in vitro cell transformation assay using BALB/3T3 cells. Two treatment periods, 48 hr and 13 days, were used. Nonoxynol-9, tested at levels up to 10 pglml, did not induce transf
Loss of density-dependent regulation of multiplication of BALB/3T3 cells chemically transformed in vitro
β Scribed by Y. Oshiro; J. A. DiPaolo
- Publisher
- John Wiley and Sons
- Year
- 1973
- Tongue
- English
- Weight
- 477 KB
- Volume
- 81
- Category
- Article
- ISSN
- 0021-9541
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β¦ Synopsis
Abstract
Balb/3T3 cells show densityβdependent regulation of multiplication with the final cell density depending on serum concentration in the media. Chemically transformed Balb/3T3 cells (Balb/3T3βD) pile up on each other, multiply to a high cell density, but have decreased DNA synthesis at very high cell densities. Balb/3T3βD cells require less serum for multiplication compared with original Balb/3T3 cells. A rat serum fraction and a bovine Ξ²βglobulin fraction stimulate the multiplication of Balb/3T3 cells but only slightly stimulate Balb/3T3βD cells indicating different serum factors stimulate growth of these two cell types. The multiplication properties of Balb/3T3βD cells are very similar to those of SVβ40 transformed 3T3 cells, however, these properties were brought about by a single treatment by a chemical carcinogen, without an exogenous virus. The transformation altered the contact of cells to one another, indicating a permanent chemical change in the membrane structure.
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