Related Experiment Video

Updated: Sep 8, 2025

Identification of Nucleolar Factors During HIV-1 Replication Through Rev Immunoprecipitation and Mass Spectrometry
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ebv-sisRNA-3 contributes to the formation of G4-associated R-loop upstream of EBV lytic replication origin in

Bo Wang1, Grace Tin Yun Chung1, Yi Shuai1

  • 1Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China.

Cell & Bioscience
|June 27, 2025
PubMed
Abstract

Insights

A novel Epstein-Barr virus (EBV) transcript, ebv-sisRNA-3, is abundant in epithelial cancers. This non-coding RNA forms R-loop and G-quadruplex structures, potentially regulating EBV lytic replication.

Area of Science:

  • Virology
  • Molecular Biology
  • Cancer Research

Background:

  • Epstein-Barr virus (EBV) uses non-coding RNAs to evade host immunity in epithelial cancers.
  • The roles of many EBV-encoded non-coding RNAs in cancer latency and progression are not fully understood.

Purpose of the Study:

  • To identify and characterize novel EBV-encoded non-coding RNAs in epithelial cancers.
  • To investigate the function of ebv-sisRNA-3 in EBV-infected cells.

Main Methods:

  • Analysis of EBV-positive nasopharyngeal carcinoma and gastric cancer specimens.
  • RNA sequencing and Northern blot to detect ebv-sisRNA-3.
  • DNA-damage response assays to identify R-loop and G-quadruplex formation.

Main Results:

  • Abundant expression of a novel 5-7 kb non-polyadenylated transcript, ebv-sisRNA-3, was detected in EBV-associated cancers.
  • ebv-sisRNA-3 accumulates in the nucleus and invades EBV DNA, forming R-loops and G-quadruplexes near the lytic replication origin.
  • Endogenous R-loops and G-quadruplexes were identified near EBER1 and EBNA1 promoters.

Conclusions:

  • ebv-sisRNA-3 is a novel, widely expressed EBV transcript in latently infected cells.
  • The unique R-loop and G-quadruplex structures induced by ebv-sisRNA-3 may regulate EBV lytic replication.
Keywords:
Epstein-barr virusG-quadruplexNasopharyngeal carcinomaR-loopncRNAsisRNA

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