A novel tumor suppressing role for RUNX3 is shown where a direct interaction with MYC leads to disruption of MYC-MAX heterodimers and consequent degradation of the MYC oncoprotein

Developmental regulator RUNX3 targets MYC protein for rapid degradation through the glycogen synthase kinase-3 beta-box/WD repeat-containing protein 7 (GSK3ß-FBXW7) proteolytic pathway. We therefore uncover a previously unknown mode of MYC destabilization by RUNX3 and provide an explanation as to why RUNX3 inhibits early-stage cancer development in gastrointestinal and lung mouse cancer models. Overall design: Transcriptional profiling of HeLa-RUNX3 and MKN28-RUNX3 doxycycline inducible cell lines comparing non-treated samples with doxycycline-treatment (RUNX3 induction) samples. The aim of this experiment was to evaluate the functions and effects of RUNX3 induction in these cell lines in vitro. There are three replicates for each condition.