Human cytomegalovirus preferentially infects the neoplastic epithelium of colorectal cancer: a quantitative and histological analysis

J Clin Virol. 2012 Jul;54(3):240-4. doi: 10.1016/j.jcv.2012.04.007. Epub 2012 May 15.

Abstract

Background: It has long been suggested that human cytomegalovirus (HCMV) might be involved in human oncogenesis. However, whether HCMV was associated with colorectal cancer (CRC) was still controversial.

Objective: To clarify whether HCMV specifically infects the tumorous tissue of CRC.

Study design: Paired tumor and adjacent non-neoplastic CRC specimens were collected from 163 patients. HCMV DNA was detected and quantified through PCR and quantitative real-time PCR. Virus location was determined by in situ hybridization (ISH) of formalin-fixed paraffin-embedded tissue sections with an HCMV-specific probe.

Results: By PCR, HCMV DNA was detected in 42.3% (69/163) of the tumor specimens, while only 5.6%(14/163) samples of adjacent non-neoplastic tissue were positive for HCMV (p<0.0001). Quantitative real-time PCR in 54 sample pairs revealed significantly higher viral copies in the tumor specimens than the adjacent non-neoplastic tissue specimens (p<0.001). By ISH, the nucleic acids of HCMV were detected in the cytoplasm of neoplastic epithelium. No hybridization was detected in the inflammatory infiltrates, submucosa, or other stromal tissues.

Conclusions: HCMV preferentially infects the tumor epithelium of CRC. How the virus subsists in and interacts with the microenvironment of tumor epithelium of CRC should be studied.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Colorectal Neoplasms / complications*
  • Colorectal Neoplasms / virology*
  • Cytomegalovirus / genetics
  • Cytomegalovirus / isolation & purification*
  • Cytomegalovirus / pathogenicity*
  • Cytomegalovirus Infections / complications*
  • Cytomegalovirus Infections / virology*
  • DNA, Viral / genetics
  • DNA, Viral / isolation & purification
  • Epithelium / virology*
  • Humans
  • In Situ Hybridization
  • Real-Time Polymerase Chain Reaction
  • Viral Load

Substances

  • DNA, Viral