Effects of the N-Ras Oncogene on the Expression of Other Cellular Genes in CO25 Myoblast Cells


Abstract: The effects of the N- ras oncogene on the transcription levels of c- myc, p53, c-K-ras and b-actin genes have been investigated by Northern blotting in a cell line which normally differentiates into myotubes. Treatment of cells with dexamethasone activates N- ras gene, then cells proliferate and form foci. The transcription level of c- myc gene was generally high during transformation whereas c-K- ras mRNAs levels were high during differentiation. Following induction of the N- ras oncogene, the level of c-myc mRNA first decreased in two days and then increased in three and four days. During differentiation, c-K- ras mRNA decreased in three days and increased following day. The level of b-actin mRNA was slightly lower during transformation, and there were no changes in the mRNA levels of p53 and c- K-ras. An increase in the level of c- myc mRNA in four days of differentiation when myo-tubes form, shows that expression of c- myc may not have an effect after this critical period of differentiation.

Keywords: oncogene, myoblast, ras, myc, differentiation.

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