SNAIL and miR-34a feed-forward regulation of ZNF281/ZBP99 promotes epithelial-mesenchymal transition

Here, we show that expression of ZNF281/ZBP‐99 is controlled by SNAIL and miR‐34a/b/c in a coherent feed‐forward loop: the epithelial–mesenchymal transition (EMT) inducing factor SNAIL directly induces ZNF281 transcription and represses miR‐34a/b/c , thereby alleviating ZNF281 mRNA from direct down‐regulation by miR‐34. Furthermore, p53 activation resulted in a miR‐34a ‐dependent repression of ZNF281. Ectopic ZNF281 expression in colorectal cancer (CRC) cells induced EMT by directly activating SNAIL , and was associated with increased migration/invasion and enhanced β‐catenin activity. Furthermore, ZNF281 induced the stemness markers LGR5 and CD133, and increased sphere formation. Conversely, experimental down‐regulation of ZNF281 resulted in mesenchymal–epithelial transition (MET) and inhibition of migration/invasion, sphere formation and lung metastases in mice. Ectopic c‐MYC induced ZNF281 protein expression in a SNAIL‐dependent manner. Experimental inactivation of ZNF281 prevented EMT induced by c‐MYC or SNAIL. In primary CRC samples, expression of ZNF281 increased during tumour progression and correlated with recurrence. Taken together, these results identify ZNF281 as a component of EMT‐regulating networks, which contribute to metastasis formation in CRC. This study establishes the Krüppel‐like zinc‐finger protein ZNF281 as a novel regulator of an EMT programme while integrating it into complex feedback regulation that includes SNAIL‐miR‐34a and p53/Myc.