title: Epstein-barr virus infected gastric adenocarcinoma expresses latent and lytic viral transcripts and has a distinct human gene expression profile.
abstract: BACKGROUND
  EBV DNA is found within the malignant cells of 10% of gastric cancers. Modern molecular technology facilitates identification of virus-related biochemical effects that could assist in early diagnosis and disease management.
  
  
  METHODS
  In this study, RNA expression profiling was performed on 326 macrodissected paraffin-embedded tissues including 204 cancers and, when available, adjacent non-malignant mucosa. Nanostring nCounter probes targeted 96 RNAs (20 viral, 73 human, and 3 spiked RNAs).
  
  
  RESULTS
  In 182 tissues with adequate housekeeper RNAs, distinct profiles were found in infected versus uninfected cancers, and in malignant versus adjacent benign mucosa. EBV-infected gastric cancers expressed nearly all of the 18 latent and lytic EBV RNAs in the test panel. Levels of EBER1 and EBER2 RNA were highest and were proportional to the quantity of EBV genomes as measured by Q-PCR. Among protein coding EBV RNAs, EBNA1 from the Q promoter and BRLF1 were highly expressed while EBNA2 levels were low positive in only 6/14 infected cancers. Concomitant upregulation of cellular factors implies that virus is not an innocent bystander but rather is linked to NFKB signaling (FCER2, TRAF1) and immune response (TNFSF9, CXCL11, IFITM1, FCRL3, MS4A1 and PLUNC), with PPARG expression implicating altered cellular metabolism. Compared to adjacent non-malignant mucosa, gastric cancers consistently expressed INHBA, SPP1, THY1, SERPINH1, CXCL1, FSCN1, PTGS2 (COX2), BBC3, ICAM1, TNFSF9, SULF1, SLC2A1, TYMS, three collagens, the cell proliferation markers MYC and PCNA, and EBV BLLF1 while they lacked CDH1 (E-cadherin), CLDN18, PTEN, SDC1 (CD138), GAST (gastrin) and its downstream effector CHGA (chromogranin). Compared to lymphoepithelioma-like carcinoma of the uterine cervix, gastric cancers expressed CLDN18, EPCAM, REG4, BBC3, OLFM4, PPARG, and CDH17 while they had diminished levels of IFITM1 and HIF1A. The druggable targets ERBB2 (Her2), MET, and the HIF pathway, as well as several other potential pharmacogenetic indicators (including EBV infection itself, as well as SPARC, TYMS, FCGR2B and REG4) were identified in some tumor specimens.
  
  
  CONCLUSIONS
  This study shows how modern molecular technology applied to archival fixed tissues yields novel insights into viral oncogenesis that could be useful in managing affected patients.
authors.affiliation: Department of Pathology & Laboratory Medicine, Lineberger Comprehensive Cancer Center, University of North Carolina, 913 Brinkhous-Bullitt Building, Chapel Hill, NC, 27599-7525, USA. margaret_gulley@med.unc.edu.
authors.forename: Weihua
authors.initials: W
authors.lastname: Tang
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Morgan
authors.forename: Michael O
authors.initials: MO
authors.lastname: Meyers
authors.forename: Ricardo L
authors.initials: RL
authors.lastname: Dominguez
authors.forename: Enrique
authors.initials: E
authors.lastname: Martinez
authors.forename: Kennichi
authors.initials: K
authors.lastname: Kakudo
authors.forename: Pei Fen
authors.initials: PF
authors.lastname: Kuan
authors.forename: Natalie
authors.initials: N
authors.lastname: Banet
authors.forename: Hind
authors.initials: H
authors.lastname: Muallem
authors.forename: Kimberly
authors.initials: K
authors.lastname: Woodward
authors.forename: Olga
authors.initials: O
authors.lastname: Speck
authors.forename: Margaret L
authors.initials: ML
authors.lastname: Gulley