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[The characteristics and significance of oncogenes expression in oval cells cultivated in vitro].

OBJECTIVE
To study the relationship between expression characteristics of oncogenes and transformation of the oval cells cultivated in vitro.


METHODS
Liver oval cells of SD rats induced by feeding with chemical carcinogen 3'-Me-DAB for four weeks were isolated using Percoll density gradient centrifugation. The cells were continuously cultivated in vitro and the dynamic characteristics of Ha-ras, Ki-ras and c-myc genes expression in the oval cells were detected using RNA-DNA slot blot hybridization.


RESULTS
During long term cultivation, the population doubling time of the cells became shorter and the percentage of aneuploidy chromosomes and colonies grown in soft agar increased. Ha-ras Ki-ras and c-myc were synchronically expressed in the oval cells from different passages.


CONCLUSION
The activation and synergistic over-expression of Ha-ras Ki-ras and c-myc had an important role in the proliferation and transformation of oval cells in vitro.