title: Identification of a novel human endogenous retrovirus and promoter activity of its 5' U3.
abstract: Up-regulation of human endogenous retroviruses (HERVs) sometimes occurs in cancer. This study identifies a novel HERV (HERV-HX) in colon tumor tissues, which is an H family HERV (HERV-H) element located on chromosome Xp22.32. The full-length transcript sequence was identified and characterized. Quantitative RT-PCR indicated it is up-regulated in colon tumor samples. Using RT-PCR to analyze the transcription of the env-deleted HERV-HX and other env-intact HERV-H elements, it was demonstrated that transcription of HERV-H in colon cancer is not associated with the env gene. A 17-bp sequence was found within the 5' U3 region of HERV-HX, and only 8-bp sequences existed on its homologous U3 regions in the corresponding loci. Promoter activity assays indicated that replacing the 17-bp sequence with an 8-bp sequence or deleting it reduced its activity, suggesting that the 17-bp sequence is important to the expression of HERV-HX.
authors.affiliation: Cancer Institute, Second Affiliated Hospital, and Ministry of Education Key Laboratory of Cancer Prevention and Intervention, Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: Qiaoyi
authors.initials: Q
authors.lastname: Liang
authors.forename: Jiayi
authors.initials: J
authors.lastname: Ding
authors.forename: Rongzhen
authors.initials: R
authors.lastname: Xu
authors.forename: Zefeng
authors.initials: Z
authors.lastname: Xu
authors.forename: Shu
authors.initials: S
authors.lastname: Zheng
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics*; D001483:Base Sequence; D003110:Colonic Neoplasms / Q000235:genetics / Q000821:virology*; D020077:Endogenous Retroviruses / Q000235:genetics* / Q000302:isolation & purification; D015967:Gene Expression Regulation, Viral; D052138:Genes, Neoplasm; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic
chemical_list: D020121:5' Untranslated Regions