PLK4 was identified as a promising therapeutic target through a systematic approach that combined RNAi screening with gene expression analysis in human breast cancers and cell lines. A drug discovery program culminated in CFI-400945, a potent and selective PLK4 inhibitor. Cancer cells treated with CFI-400945 exhibit effects consistent with PLK4 kinase inhibition, including dysregulated centriole duplication, mitotic defects, and cell death. Oral administration of CFI-400945 to mice bearing human cancer xenografts results in the significant inhibition of tumor growth at doses that are well tolerated. Increased antitumor activity in vivo was observed in PTEN-deficient compared to PTEN wild-type cancer xenografts. Our findings provide a rationale for the clinical evaluation of CFI-400945 in patients with solid tumors, in particular those deficient in PTEN.

No abstract

The cellular prion protein (PrP) is a highly conserved, widely expressed, glycosylphosphatidylinositolanchored (GPI-anchored) cell surface glycoprotein. Since its discovery, most studies on PrP have focused on its role in neurodegenerative prion diseases, whereas its function outside the nervous system remains unclear. Here, we report that human pancreatic ductal adenocarcinoma (PDAC) cell lines expressed PrP. However, the PrP was neither glycosylated nor GPI-anchored, existing as pro-PrP and retaining its GPI anchor peptide signal sequence (GPI-PSS). We also showed that the PrP GPI-PSS has a filamin A-binding (

Loss of cell-cycle control is a hallmark of human cancer. Cell-cycle checkpoints are essential for maintaining genome integrity and balanced growth and division. They are specifically deregulated in cancer cells and contain regulators that represent potential therapeutic targets. Monopolar spindle 1 (Mps1; also known as TTK protein kinase) is a core component of the spindle assembly checkpoint (SAC), a genome-surveillance mechanism that is important for cell survival, and has emerged as a candidate target for anticancer therapy. Here, we report the cellular and antitumor effects of CFI-402257, a potent (Mps1 K i = 0.09 ± 0.02 nM; cellular Mps1 EC 50 = 6.5 ± 0.5 nM), highly selective, and orally active small-molecule inhibitor of Mps1 that was identified through a drug-discovery program. Human cancer cells treated with CFI-402257 exhibit effects consistent with Mps1 kinase inhibition, specifically SAC inactivation, leading to chromosome missegregation, aneuploidy, and ultimately cell death. Oral administration of CFI-402257 in monotherapy or in combination with an anti-programmed cell death 1 (PD-1) antibody in mouse models of human cancer results in inhibition of tumor growth at doses that are well-tolerated. Our findings provide a rationale for the clinical evaluation of CFI-402257 in patients with solid tumors.Mps1/TTK | inhibitor | CFI-402257 | cancer