<p>PDF - 1019K, Figure S1 The CIN70 signature predicts survival in PDAC patients. Figure S2 Murine PDAC KRC cells exhibit chromosome instability and evidence of a weakened SAC. Figure S3 Clonogenic survival of PANC-1 and BxPC3 cells treated with NMS-P715. Figure S4 Growth of human adipose stem cells (ASCs) in the presence of NMS-P715. Figure S5 Murine PDAC KRC cell growth is inhibited by NMS-P715. Figure S6 Inhibition of PDAC cell growth after pre-treatment with NMS-P715. Table S1 Chromosome stability in cell lines. Table S2 PDAC CIN25 genes ranked by Cox score Supplementary methods for gene expression and survival analyses.</p>
ARTICLE ABSTRACT
Most solid tumors, including pancreatic ductal adenocarcinoma (PDAC), exhibit structural and numerical chromosome instability (CIN). Although often implicated as a driver of tumor progression and drug resistance, CIN also reduces cell fitness and poses a vulnerability that can be exploited therapeutically. The spindle assembly checkpoint (SAC) ensures correct chromosome-microtubule attachment, thereby minimizing chromosome segregation errors. Many tumors exhibit upregulation of SAC components such as MPS1, which may help contain CIN within survivable limits. Prior studies showed that MPS1 inhibition with the small molecule NMS-P715 limits tumor growth in xenograft models. In cancer cell lines, NMS-P715 causes cell death associated with impaired SAC function and increased chromosome missegregation. Although normal cells appeared more resistant, effects on stem cells, which are the dose-limiting toxicity of most chemotherapeutics, were not examined. Elevated expression of 70 genes (CIN70), including MPS1, provides a surrogate measure of CIN and predicts poor patient survival in multiple tumor types. Our new findings show that the degree of CIN70 upregulation varies considerably among PDAC tumors, with higher CIN70 gene expression predictive of poor outcome. We identified a 25 gene subset (PDAC CIN25) whose overexpression was most strongly correlated with poor survival and included MPS1. In vitro, growth of human and murine PDAC cells is inhibited by NMS-P715 treatment, whereas adipose-derived human mesenchymal stem cells are relatively resistant and maintain chromosome stability upon exposure to NMS-P715. These studies suggest that NMS-P715 could have a favorable therapeutic index and warrant further investigation of MPS1 inhibition as a new PDAC treatment strategy. Mol Cancer Ther; 13(2); 307–15. ©2013 AACR.
