Figure 2

EBV-encoded RNA levels are high in infected gastric cancer and are proportion to EBV genome level. A. Box plots of EBER1 and EBER2 in benign and malignant tissues reveal that EBV-infected gastric cancer has substantially higher levels of EBER1 and EBER2 non-coding RNAs than do uninfected cancers and control tissues. Proposed thresholds for EBER1 or EBER2 are shown beyond which a gastric cancer could reliably be designated as EBV-infected. Each dot represents an individual analytic result on a log2 normalized unit (NU) scale. B. Pairwise comparison of EBER1 and EBER2 RNA levels by Nanostring nCounter array and EBV DNA viral load by Q-PCR reveals a linear association between levels of each of these analytes. Pearson correlation coefficients (P > 0.86) are shown. The previously validated level of EBV DNA viral load is shown beyond which EBER was always localized to malignant cells by EBER in situ hybridization (threshold of 10,558 EBV genomes per 100,000 cells, which is equivalent to 13.37 on this log2 scale)[46]. Proposed cutoffs for RNA levels are indicated for both EBER1 (200,000 NU, or 17.61 on this log 2 scale) and EBER2 (100,000 NU, or 16.61 on this log2 scale). The one outlier is a non-malignant gastric mucosa that was located adjacent to an EBV-infected gastric cancer, and this mucosa had an EBV DNA load equivalent to that of infected cancers, but it would have been correctly excluded from the EBV-infected cancer group if either EBER1 or EBER2 RNA levels were used, or if histology were used, to screen for EBV-related malignancy.