Moreover, a cancer-derived ATF3 mutant (R88G) devoid of ubiquitination failed to prevent p53 from MDM2-mediated degradation and thus was unable to activate the tumor suppressor.
Expression of the dominant-negative p53 R248W mutant due to TM significantly reduced the transactivation of several established p53 target genes that mediate the tumor-suppressor function, including <i>CDKN1A</i> (p21) and <i>BBC3</i> (PUMA).
The XRCC1 R194W polymorphism was associated with a modest increased risk of TP53 tumor mutations in those who regularly smoked cigarettes (odds ratio, 1.4; 95% confidence interval, 1.02-1.9).
In contrast to the endometrioid-type tumor, all 3 mutations in 5 serous-type tumors (R273H, 9-bp deletion in codons 240-243, and R248W) showed dominant-negative capacity and presented in a homozygous state in the tumors, indicating a complete functional inactivation.
We show results that indicate that expression of these specific ribosomal protein genes is increased in the presence of the R248W p53 mutant, which provides a mechanism for their overexpression in human tumors.