A clinically feasible multiplex proteomic immunoassay as a novel functional diagnostic for pancreatic ductal adenocarcinoma

// Kian-Huat Lim 1 , Emma Langley 5 , Feng Gao 4 , Jingqin Luo 4 , Lin Li 1 , Gary Meyer 5 , Phillip Kim 5 , Sharat Singh 5 , Vladamir M. Kushnir 2 , Dayna S. Early 2 , Daniel K. Mullady 2 , Steven A. Edmundowicz 6 , Sachin Wani 6 , Faris M. Murad 7 , Dengfeng Cao 3 , Riad R. Azar 2 and Andrea Wang-Gillam 1 1 Division of Oncology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA 2 Division of Gastroenterology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA 3 Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA 4 Department of Surgery, Division of Public Health Sciences, Washington University School of Medicine, St. Louis, MO, USA 5 Prometheus Laboratories Inc., San Diego, CA, USA 6 Division of Gastroenterology and Hepatology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA 7 NorthShore University HealthSystem, Evanston, IL, USA Correspondence to: Andrea Wang-Gillam, email: // Keywords : pancreatic cancer, proteomics, fine-needle aspiration, signaling events, prognosis Received : January 28, 2017 Accepted : February 16, 2017 Published : February 23, 2017 Abstract To date, targeted therapy for pancreatic ductal adenocarcinoma (PDAC) remains largely unsuccessful in the clinic. Current genomics-based technologies are unable to reflect the quantitative, dynamic signaling changes in the tumor, and require larger tumor samples that are difficult to obtain in PDAC patients. Therefore, a highly sensitive functional tool that can reliably and comprehensively inform intra-tumoral signaling events is direly needed to guide treatment decision. We tested the utility of a highly sensitive proteomics-based functional diagnostic platform, Collaborative Enzyme Enhanced Reactive-immunoassay (CEER TM ), on fine-needle aspiration (FNA) samples obtained from 102 patients with radiographically-evident pancreatic tumors. Two FNA passes were collected from each patient, hybridized to customized chips coated with an array of capture antibodies, and detected using two enzyme-conjugated antibodies which emit quantifiable signals. We demonstrate that this technique is highly sensitive in detecting total and phosphorylated forms of multiple signaling molecules in FNA specimens, with reasonable correlation of marker intensities between two different FNA passes. Notably, signals of several markers were significantly higher in PDAC compared to non-cancerous samples. In PDAC samples, we found high total c-Met signal to be associated with poor survival, and confirmed this finding using an independent PDAC tissue microarray.