title: [Deletion of the env region in HERV-H-X gene and its expression in colon cancer].
abstract: OBJECTIVE
  We have identified a novel gene HERV-H-X from colon cancer tissue recently. This research was to analyze the deletion of the env region of HERV-H-X, to compare its expression with that of the env open reading frames (ORFs) in other HERV-H proviruses, and to study its differential expression in colon cancer and normal colon tissues.
  
  
  METHODS
  Multiple alignments were performed for HERV-H-X and 3 other HERV-H proviruses (HERV-H/env62, HERV-H/env60, and HERV-H/env59) containing intact env ORF. HERV-H-X-specific polymerase chain reaction (PCR) and env ORF-common PCR for HERV-H/env62, env60 and env59 were conducted to study their expression in 8 pairs of colon cancer and adjacent normal tissues. Real-time quantitative PCR was conducted to study the differential expression of HERV-H-X in 17 pairs of colon cancer and adjacent normal tissues.
  
  
  RESULTS
  The missing part in the env region of HERV-H-X corresponded to env ORFs in HERV-H/env62, HERV-H/env60 and HERV-H/env59. HERV-H-X was only detected in colon cancer tissues, while env ORFs were detected both in cancer and normal tissues. The expression of HERV-H-X was up-regulated in colon cancer tissues by 24.9 folds of that in normal tissues (P<0.01).
  
  
  CONCLUSIONS
  HERV-H-X is highly expressed in colon cancer, but its up-regulation is not related to env gene as it lacks an env ORF.
authors.affiliation: Cancer Institute, The Second Affiliated Hospital, Zhejiang University, Hangzhou, Zhejiang, 310009, PR China.
authors.forename: Qiao-Yi
authors.initials: QY
authors.lastname: Liang
authors.forename: Ze-Feng
authors.initials: ZF
authors.lastname: Xu
authors.forename: Rong-Zhen
authors.initials: RZ
authors.lastname: Xu
authors.forename: Shu
authors.initials: S
authors.lastname: Zheng
authors.forename: Jia-Yi
authors.initials: JY
authors.lastname: Ding
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D003106:Colon / Q000378:metabolism; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D020077:Endogenous Retroviruses / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D015752:Genes, env; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017384:Sequence Deletion
chemical_list: D018076:DNA, Complementary