title: Using Quantitative Seroproteomics to Identify Antibody Biomarkers in Pancreatic Cancer.
abstract: Pancreatic cancer is the fourth leading cause of cancer-related deaths in the United States. Less than 6% of patients survive beyond the fifth year due to inadequate early diagnostics and ineffective treatment options. Our laboratory has developed an allogeneic, granulocyte-macrophage colony-stimulating factor (GM-CSF)-secreting pancreatic cancer vaccine (GVAX) that has been tested in phase II clinical trials. Here, we employed a serum antibodies-based SILAC immunoprecipitation (SASI) approach to identify proteins that elicit an antibody response after vaccination. The SASI approach uses immunoprecipitation with patient-derived antibodies that is coupled to quantitative stable isotope-labeled amino acids in cell culture (SILAC). Using mass spectrometric analysis, we identified more than 150 different proteins that induce an antibody response after vaccination. The regulatory subunit 12A of protein phosphatase 1 (MYPT1 or PPP1R12A), regulatory subunit 8 of the 26S proteasome (PSMC5), and the transferrin receptor (TFRC) were shown to be pancreatic cancer-associated antigens recognized by postvaccination antibodies in the sera of patients with favorable disease-free survival after GVAX therapy. We further interrogated these proteins in over 80 GVAX-treated patients' pancreases and uniformly found a significant increase in the expression of MYPT1, PSMC5, and TFRC in neoplastic compared with non-neoplastic pancreatic ductal epithelium. We show that the novel SASI approach can identify antibody targets specifically expressed in patients with improved disease-free survival after cancer vaccine therapy. These targets need further validation to be considered as possible pancreatic cancer biomarkers.
authors: Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland. Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Skip Viragh Center for Pancreatic Cancer Research and Clinical Care and The Sol Goldman Pancreatic Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Darshil T
authors: DT
authors: Jhaveri
authors: McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Min-Sik
authors: MS
authors: Kim
authors: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Elizabeth D
authors: ED
authors: Thompson
authors: Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Skip Viragh Center for Pancreatic Cancer Research and Clinical Care and The Sol Goldman Pancreatic Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Lanqing
authors: L
authors: Huang
authors: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Rajni
authors: R
authors: Sharma
authors: Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Skip Viragh Center for Pancreatic Cancer Research and Clinical Care and The Sol Goldman Pancreatic Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Alison P
authors: AP
authors: Klein
authors: Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Skip Viragh Center for Pancreatic Cancer Research and Clinical Care and The Sol Goldman Pancreatic Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Lei
authors: L
authors: Zheng
authors: Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Skip Viragh Center for Pancreatic Cancer Research and Clinical Care and The Sol Goldman Pancreatic Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Dung T
authors: DT
authors: Le
authors: Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Skip Viragh Center for Pancreatic Cancer Research and Clinical Care and The Sol Goldman Pancreatic Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors: Daniel A
authors: DA
authors: Laheru
authors: Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Skip Viragh Center for Pancreatic Cancer Research and Clinical Care and The Sol Goldman Pancreatic Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland. McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland. Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland. Adrienne Helis Malvin Medical Research Foundation and Diana Helis Henry Medical Research Foundation, New Orleans, Louisiana.
authors: Akhilesh
authors: A
authors: Pandey
authors: Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland. Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland. The Skip Viragh Center for Pancreatic Cancer Research and Clinical Care and The Sol Goldman Pancreatic Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland. rander54@jhmi.edu ejaffee@jhmi.edu.
authors: Elizabeth M
authors: EM
authors: Jaffee
authors: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland. rander54@jhmi.edu ejaffee@jhmi.edu.
authors: Robert A
authors: RA
authors: Anders
mesh_terms: D000074183:ATPases Associated with Diverse Cellular Activities; D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000912:Antibodies, Neoplasm / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood*; D019496:Cancer Vaccines / Q000627:therapeutic use; D021441:Carcinoma, Pancreatic Ductal / Q000097:blood* / Q000276:immunology / Q000628:therapy; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D006801:Humans; D060588:LIM Domain Proteins / Q000378:metabolism; D043263:Myosin-Light-Chain Phosphatase / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000097:blood* / Q000276:immunology / Q000628:therapy; D046988:Proteasome Endopeptidase Complex; D040901:Proteomics; D014157:Transcription Factors / Q000378:metabolism; D016896:Treatment Outcome; D014611:Vaccination
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000912:Antibodies, Neoplasm; D014408:Biomarkers, Tumor; D019496:Cancer Vaccines; D060588:LIM Domain Proteins; C092282:PSMC5 protein, human; D014157:Transcription Factors; D043263:Myosin-Light-Chain Phosphatase; C490372:PPP1R12A protein, human; D046988:Proteasome Endopeptidase Complex; D000074183:ATPases Associated with Diverse Cellular Activities