title: Serological and viraemic status of human cytomegalovirus infection in patients with colorectal cancer is not correlated with viral replication and transcription in tumours.
abstract: Colorectal cancer (CRC) is amongst the leading causes of cancer-related mortality worldwide. Emerging evidence suggests that human cytomegalovirus (HCMV) exists in the tumour tissue of CRC and is associated with disease outcome. To study whether tumoral HCMV is related to viral reactivation in blood, tumour specimens and pre- and post-operative blood samples from CRC patients were collected prospectively. PCR and quantitative PCR were performed to detect HCMV DNA. HCMV IgG and IgM antibodies were measured using a microparticle enzyme immunoassay. Transcription of a spliced HCMV UL73 gene transcript was analysed by quantitative reverse transcription PCR. HCMV was detected in 42.2% (35/83) of the tumour samples, with a low median viral load (30.08, range 2.33-5704 copies per 500  ng genomic DNA). The vast majority (80/81, 98.8%) of the CRC patients were seropositive for HCMV IgG. HCMV DNA was positive in 11.3% (22/194) of the pre-operative and 8.9% (15/168) of the post-operative blood samples. However, presence of HCMV and its viral load in tumours were not associated with the detection or viral loads in blood samples. About 26.67% (8/30) of the HCMV-positive tumours with available RNA had detectable viral UL73 transcripts, whilst none of the blood samples were positive for viral RNA (P < 0.0001). Therefore, presence of HCMV in tumours does not correlate with the serological or viraemic status of CRC patients. Active viral gene transcription occurred in the tumour but not in the blood of CRC patients. HCMV reactivation in CRC patients is possibly due to virus-cancer interactions in the CRC tumour microenvironment.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Hsin-Pai
authors.initials: HP
authors.lastname: Chen
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei, Taiwan.|Division of Colon and Rectal Surgery, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Jeng-Kai
authors.initials: JK
authors.lastname: Jiang
authors.affiliation: Institute of Public Health, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Pei-Yu
authors.initials: PY
authors.lastname: Lai
authors.affiliation: Department of Biotechnology and Laboratory Science in Medicine, School of Biomedical Science and Engineering, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Wan-Huai
authors.initials: WH
authors.lastname: Teo
authors.affiliation: Department of Education and Research, Taipei City Hospital, Taipei, Taiwan.
authors.forename: Chih-Yung
authors.initials: CY
authors.lastname: Yang
authors.affiliation: Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan.|Division of Molecular Pathology, Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Teh-Ying
authors.initials: TY
authors.lastname: Chou
authors.affiliation: Institute of Microbiology and Immunology, School of Life Science, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chi-Hung
authors.initials: CH
authors.lastname: Lin
authors.affiliation: Division of Microbiology, Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Institute of Public Health, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yu-Jiun
authors.initials: YJ
authors.lastname: Chan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood*; D015179:Colorectal Neoplasms / Q000150:complications*; D003587:Cytomegalovirus / Q000502:physiology*; D003586:Cytomegalovirus Infections / Q000276:immunology* / Q000821:virology; D004279:DNA, Viral / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D014158:Transcription, Genetic; D019562:Viral Load; D014779:Virus Replication
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M