CEP164 Deficiency Causes Hyperproliferation of Pancreatic Cancer Cells

Abstract

Primary cilia are hair-like projections that protrude from most mammalian cells and mediate various extracellular signaling pathways. Pancreatic ductal adenocarcinoma (PDAC) cells are known to lose their primary cilia, but the relevance of this phenomenon remains unclear. In this study, we generated PDAC-originated Panc1 cells devoid of primary cilia by mutating a centriolar protein, centrosomal protein 164 (CEP164), which is required for ciliogenesis. CEP164 depletion enhanced the clonogenicity of Panc1 cells, along with chemically induced elimination of primary cilia, suggesting that a lack of these organelles promotes PDAC cells proliferation. In addition, the loss of CEP164 altered the cell cycle progression irrespective of absence of primary cilia. We found that CEP164 was co-localized with the GLI2 transcription factor at the mother centriole and controlled its activation, thus inducing Cyclin D-CDK6 expression. Furthermore, CEP164-mutated Panc1 cells were significantly tolerant to KRAS depletion-dependent growth inhibition. This study suggests that CEP164 deficiency is advantageous for PDAC cells proliferation due to not only lack of ciliation but also ciliaindependent GLI2-Cyclin D/CDK6 activation, and that CEP164 is a potential therapeutic target for PDAC.

Molecular mechanisms underlying the role of the centriolar CEP164-TTBK2 complex in ciliopathies

“…In agreement with this model, lack of CEP164 or TTBK2 impairs ciliogenesis in mammalian tissue culture cells and mouse models without otherwise affecting centriole structure ( Bowie and Goetz, 2020 ; Cajanek and Nigg, 2014 ; Goetz et al., 2012 ; Graser et al., 2007 ; Humbert et al., 2012 ; Kobayashi et al., 2020 ; Lo et al., 2019 ; Oda et al., 2014 ; Schmidt et al., 2012 ; Slaats et al., 2014 ). Furthermore, CEP164 or TTBK2 truncations that lack their respective TTBK2- or CEP164-interacting region do not support ciliogenesis in vivo ( Bowie et al., 2018 ; Cajanek and Nigg, 2014 ; Goetz et al., 2012 ; Kobayashi et al., 2020 ; Oda et al., 2014 ).…”

“…In agreement with this model, lack of CEP164 or TTBK2 impairs ciliogenesis in mammalian tissue culture cells and mouse models without otherwise affecting centriole structure ( Bowie and Goetz, 2020 ; Cajanek and Nigg, 2014 ; Goetz et al., 2012 ; Graser et al., 2007 ; Humbert et al., 2012 ; Kobayashi et al., 2020 ; Lo et al., 2019 ; Oda et al., 2014 ; Schmidt et al., 2012 ; Slaats et al., 2014 ). Furthermore, CEP164 or TTBK2 truncations that lack their respective TTBK2- or CEP164-interacting region do not support ciliogenesis in vivo ( Bowie et al., 2018 ; Cajanek and Nigg, 2014 ; Goetz et al., 2012 ; Kobayashi et al., 2020 ; Oda et al., 2014 ). Consistently, overexpression of the WW domain-containing N-terminal region of CEP164 in tissue culture cells results in a dominant-negative effect on cilia formation, probably by competing with TTBK2 association with CEP164 at distal appendages ( Cajanek and Nigg, 2014 ; Chaki et al., 2012 ; Slaats et al., 2014 ; Schmidt et al., 2012 ).…”

KIF24 controls the clustering of supernumerary centrosomes in pancreatic ductal adenocarcinoma cells

“…In contrast to the substantial decrease in primary ciliation (Figure 2D), cell growth was not affected by silencing of IFT88 in WT and Kif24-3 cells (Figure 2E). To further confirm the primary cilia-independent hyperproliferation of Kif24-3 cells, cells were treated with chloral hydrate (ClHy), which is known to exclude primary cilia from the cell surface (Ho et al , 2013; Kobayashi et al , 2020). ClHy-treatment significantly reduced ciliation but failed to impact growth in WT and Kif24-3 cells (Figure 2F, G).…”

“…Established cells were cultured in medium with puromycin. Panc1/WT_EV cells were generated previously (Kobayashi et al ., 2020).…”

Atypical small GTPase RABL3 interacts with RAB11 to regulate early ciliogenesis in human cells

“…Immunofluorescence microscopy was performed as described previously (Kobayashi et al, 2017). Quantification analysis of fluorescence was performed using ImageJ (Kobayashi et al, 2020).…”