p73 is effective in p53-null pancreatic cancer cells resistant to wild-type TP53 gene replacement.

Novel therapies such as gene therapy are needed for the treatment of pancreatic carcinomas. Here we show that adenovirus-mediated p73 overexpression results in a strong induction of apoptosis, whereas the effect of p53 varies between different cell lines. In particular, p53-negative AsPC-1 cells are resistant to p53-mediated apoptosis. In these cells, only ectopically expressed p73 activates the proapoptotic p53 target P53AIP1, whereas phosphorylation of p53 at Ser-46, shown to regulate transcriptional activation of P53AIP1, is missing. Our findings support the use of p73 as an anticancer drug in p53-null pancreatic cancer cells that are resistant to wild-type TP53 gene replacement.