Capture and characterization of 5-aza-2'-deoxycytidine-treated C3H/10T1/2 cells prior to transformation.
A model system was developed to capture phenotypically normal cells committed to transformation to address two fundamental questions in cancer biology: (i) what are the earliest events in transformation; and (ii) what is the role of DNA methylation in carcinogenesis? Individual C3H/10T1/2 cells were treated with 5-aza-2'-deoxycytidine, which causes hypomethylation of DNA. Cells were grown to subconfluence, and individual microcolonies were trypsinized into two fractions. One fraction was cryopreserved, and the other was replated and maintained in culture. Ten percent of these replated colonies became morphologically transformed after 4-6 weeks. The cryopreserved ancestral cells of both transformed and nontransformed microcolonies were then cultured and compared to each other and to the transformants for phenotypic properties of cellular transformation. Pretransformed and nonpretransformed ancestral cells were initially morphologically indistinguishable, their early growth curves did not differ significantly, and they did not form colonies in soft agar. On continued growth in culture, however, the pretransformants displayed all of the phenotypic characteristics of transformation. Furthermore, transformation occurred in a given pretransformant in most or all of the cells of that clone. Thus, cells committed to transformation could be isolated in this way prior to phenotypic transformation. Studies of these pretransformed cells will permit examination of the earliest events in carcinogenesis and the role of DNA methylation in transformation.
ACESSO AO ARTIGOhttp://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=281976
- DNA methylation in 5-aza-2'-deoxycytidine-resistant variants of C3H 10T1/2 C18 cells.
- Increased radiation-induced transformation in C3H/10T1/2 cells after transfer of an exogenous c-myc gene.
- Probabilistic view of the transformation of cultured C3H/10T1/2 mouse embryo fibroblasts by 3-methylcholanthrene.
- Long-chain (sphingoid) bases inhibit multistage carcinogenesis in mouse C3H/10T1/2 cells treated with radiation and phorbol 12-myristate 13-acetate.
- A serine protease activity in C3H/10T1/2 cells that is inhibited by anticarcinogenic protease inhibitors.