Epstein-Barr virus (EBV) infection of human primary resting B lymphocytes (RBLs) leads to the establishment of lymphoblastoid cell lines (LCLs) that can grow indefinitely in vitro. EBV transforms RBLs through the expression of viral latency genes, and these genes alter host transcription programs. To globally measure the transcriptome changes during EBV transformation, primary human resting B lymphocytes (RBLs) were infected with B95.8 EBV for 0, 2, 4, 7, 14, 21, and 28 days, and poly(A) plus RNAs were analyzed by transcriptome sequencing (RNA-seq). Analyses of variance (ANOVAs) found 3,669 protein-coding genes that were differentially expressed (false-discovery rate [FDR] < 0.01). Ninety-four percent of LCL genes that are essential for LCL growth and survival were differentially expressed. Pathway analyses identified a significant enrichment of pathways involved in cell proliferation, DNA repair, metabolism, and antiviral responses. RNA-seq also identified long noncoding RNAs (lncRNAs) differentially expressed during EBV infection. Clustered regularly interspaced short palindromic repeat (CRISPR) interference (CRISPRi) and CRISPR activation (CRISPRa) found that CYTOR and NORAD lncRNAs were important for LCL growth. During EBV infection, type III EBV latency genes were expressed rapidly after infection. Immediately after LCL establishment, EBV lytic genes were also expressed in LCLs, and ∼4% of the LCLs express gp350. Chromatin immune precipitation followed by deep sequencing (ChIP-seq) and POLR2A chromatin interaction analysis followed by paired-end tag sequencing (ChIA-PET) data linked EBV enhancers to 90% of EBV-regulated genes. Many genes were linked to enhancers occupied by multiple EBNAs or NF-κB subunits. Incorporating these assays, we generated a comprehensive EBV regulome in LCLs. IMPORTANCE Epstein-Barr virus (EBV) immortalization of resting B lymphocytes (RBLs) is a useful model system to study EBV oncogenesis. By incorporating transcriptome sequencing (RNA-seq), chromatin immune precipitation followed by deep sequencing (ChIP-seq), chromatin interaction analysis followed by paired-end tag sequencing (ChIA-PET), and genome-wide clustered regularly interspaced short palindromic repeat (CRISPR) screen, we identified key pathways that EBV usurps to enable B cell growth and transformation. Multiple layers of regulation could be achieved by cooperations between multiple EBV transcription factors binding to the same enhancers. EBV manipulated the expression of most cell genes essential for lymphoblastoid cell line (LCL) growth and survival. In addition to proteins, long noncoding RNAs (lncRNAs) regulated by EBV also contributed to LCL growth and survival. The data presented in this paper not only allowed us to further define the molecular pathogenesis of EBV but also serve as a useful resource to the EBV research community.

Significance: EBV infection causes African Burkitt's lymphoma; Hodgkin's disease; lymphomas in immune suppressed people, including HIV infected people; nasopharyngeal carcinoma; and ∼10% of gastric carcinomas. We recently found EBV super-enhancer (ESE) to be critical for lymphoblastoid cell (LCL) growth and survival. We now identified an ESE constituent, enhancer RNA (eRNA), that is important for ESE function. These eRNAs were activated by viral transactivator, EBV nuclear antigen 2 (EBNA2). MYC oncogene ESE eRNAs were able to enhance ESE activation of MYC expression and are essential for LCL growth. Targeting ESE eRNAs may lead to new therapeutics for EBV-associated malignancies.

Significance: Epigenetic alterations in nasopharyngeal carcinoma (NPC) are very frequent at the DNA level. Histone modifications are frequently altered in cancers. Because histone modifications are reversible, histone-modifying enzymes or other epigenetic regulators are ideal therapeutic targets, and drugs targeting these enzymes have been proven effective in cancer treatment. Understanding the NPC histone code provides unique insights into NPC pathogenesis and will likely contribute to the identification of unique therapeutics. Using genome-wide analyses of histone modifications, we generated an NPC epigenetic landscape and identified a key oncogene whose expression correlated with patient overall survival, suggesting that epigenetic profiling can effectively identify key oncogenic pathways. These studies provide proof-of-concept strategies for further characterization of the NPC epigenome on a larger scale.