CEP164-GLI2 association ensures the hedgehog signaling in pancreatic cancer cells.

Hedgehog (Hh) signaling is involved in multiple biological events including development and cancers. It is processed through primary cilia, which are assembled from the mother centriole in most mammalian cells. Pancreatic ductal adenocarcinoma (PDAC) cells generally lose their primary cilia; thus, the Hh signaling pathway is postulated to be independent of the organelle in PDAC. We previously reported that the mother centriole-specific protein, centrosomal protein 164 (CEP164), is required for centriolar localization of the GLI2 transcription factor in Hh signaling and for suppressing the expression of Hh-target genes. In this study, we demonstrated the physical interaction between CEP164 and GLI2, and delineated their binding modes at the mother centriole. The ectopically expressed GLI2-binding region of CEP164 reduced the centriolar GLI2 localization and enhanced the expression of Hh-target genes in PDAC cells. Furthermore, similar phenotypes were observed in PDAC cells lacking primary cilia. These results suggest that the CEP164-GLI2 association at the mother centriole is responsible for controlling Hh signaling, independent of primary cilia in PDAC cells.