Mutant p53 enhances nuclear factor kappa B activation by tumor necrosis factor alpha in cancer cells

Mutations in the p53 tumor suppressor are very frequent in human cancer. Often, such mutations lead to the constitutive overproduction of mutant p53 proteins, which may exert a cancer-promoting gain of function. We now report that cancer-associated mutant p53 can augment the induction of nuclear factor kappa B (NF kappa B) transcriptional activity in response to the cytokine tumor necrosis factor alpha (TNF alpha). Conversely, down-regulation of endogenous mutant p53 sensitizes cancer cells to the apoptotic effects of TNF alpha. Analysis of human head and neck tumors and lung tumors reveals a close correlation between the presence of abundant mutant p53 proteins and the constitutive activation of NF kappa B. Together, these findings suggest that p53 mutations may promote cancer progression by augmenting NF kappa B activation in the context of chronic inflammation.