A study on the role of ras and p53 proteins on carcinogenesis

The tumor suppressor p53 gene encoding a transcriptional factor is the most widely mutated gene in human tumorigenesis and activated by ionizing radiation or oncogenic activations. P53 protein forms a complex with Mdm2 protein which is overexpressed in a variety of human cancers. p53 inactivation is also involved in the ability of ras oncogene to cause cell transformation. Therefore, effects of ras oncogene on p53 and its regulator Mdm2 expression activated by UV light were investigated in both normal and ras transform rat embryonal fibroblast cell lines. Western Blot analyses showed that ras transformation of the cells inhibited the expression of p53 gene induced by UV. This finding suggest that ras transformation cause complate suppresion of p53 and its pathway.