NUPR1 and familial pancreatic carcinoma: In this regard, the expression profile data described above reveals that Nupr1 inactivation increases FoxO3a expression,19 a transcription factor involved in cell cycle arrest, which is a key step for establishing the senescence phenotype.19, 20, 21 Experiments using RT-qPCR confirmed that siNupr1-treated pancreatic cancer cells show an increase of 2.7-fold±0.1 in the levels of FoxO3a mRNA (Figure 3a).