Zinc finger protein 746 promotes colorectal cancer progression via c-Myc stability mediated by glycogen synthase kinase 3β and F-box and WD repeat domain-containing 7

To elucidate the underlying oncogenic mechanism of zinc finger protein 746 (ZNF746), current study was conducted in colorectal cancers (CRCs). Herein, ZNF746 was overexpressed in HCT116, SW620, and SW480 cells, which was supported by CRC tissue microarray and TCGA analysis. Also, DNA microarray revealed the differentially expressed gene profile particularly related to cell cycle genes and c-Myc in ZNF746 depleted HCT116 cells. Furthermore, ZNF746 enhanced the stability of c-Myc via their direct binding through nuclear colocalization by immunoprecipitation and immunofluorescence, while ZNF746 and c-Myc exist mainly in nucleoplasm. Conversely, ZNF746 depletion attenuated phosphorylation of c-Myc (S62) and glycogen synthase kinase 3β (GSK3β) (S9) and also activated p-c-Myc (T58), which was reversed by GSK3 inhibitors such as SB-216763 and Enza. Also, c-Myc degradation by ZNF746 depletion was blocked by knockdown of F-box/WD repeat-containing protein 7 (FBW7) ubiquitin ligase or proteosomal inhibitor MG132. Additionally, the growth of ZNF746 depleted HCT116 cancer cells was retarded with decreased expression of ZNF746 and c-Myc. Overall, these findings suggest that ZNF746 promotes CRC progression via c-Myc stability mediated by GSK3 and FBW7.