title: Expression-analysis of the human endogenous retrovirus HERV-K in human astrocytic tumors.
abstract: BACKGROUND
  The human endogenous retrovirus K (HERV-K) has been acquired by the genome of human ancestors million years ago. It is the most complete of the HERVs with transcriptionally active gag, pol and env genes. Splice variants of env, which are rec, 1.5 kb transcript and Np9 have been suggested to be tumorigenic. Transcripts of HERV-K have been detected in a multitude of human cancers. However, no such reports are available concerning glioblastomas (GBM), the most common malignant brain tumor in adults. Patients have a limited prognosis of 14.6 months in median, despite standard treatment. Therefore, we elucidated whether HERV-K transcripts could be detected in these tumors and serve as new molecular target for treatment.
  
  
  RESULTS
  We analyzed human GBM cell lines, tissue samples from patients and primary cell cultures of different passages for HERV-K full length mRNA and env, rec and 1.5 kb transcripts. While the GBM cell lines U138, U251, U343 and GaMG displayed weak and U87 strong expression of the full length HERV-K, the splice products could not be detected, despite a weak expression of env mRNA in U87 cells. Very few tissue samples from patients showed weak expression of env mRNA, but none of the rec or 1.5 kb transcripts. Primary cells expressed the 1.5 kb transcript weakly in early passages, but lost HERV-K expression with extended culture time.
  
  
  CONCLUSIONS
  These data suggest that HERV-K splice products do not play a role in human malignant gliomas and therefore, are not suitable as targets for new therapy regimen.
authors.forename: Almuth Friederike
authors.initials: AF
authors.lastname: Kessler
authors.forename: Miriam
authors.initials: M
authors.lastname: Wiesner
authors.forename: Joachim
authors.initials: J
authors.lastname: Denner
authors.forename: Ulrike
authors.initials: U
authors.lastname: Kämmerer
authors.forename: Giles Hamilton
authors.initials: GH
authors.lastname: Vince
authors.forename: Thomas
authors.initials: T
authors.lastname: Linsenmann
authors.forename: Mario
authors.initials: M
authors.lastname: Löhr
authors.forename: Ralf-Ingo
authors.initials: RI
authors.lastname: Ernestus
authors.affiliation: Tumorbiology Laboratory, Department of Neurosurgery, University of Würzburg, Josef-Schneider-Str, 11, Würzburg D-97080, Germany. hagemann_c@ukw.de.
authors.forename: Carsten
authors.initials: C
authors.lastname: Hagemann
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology / Q000821:virology; D045744:Cell Line, Tumor; D020077:Endogenous Retroviruses / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D015967:Gene Expression Regulation, Viral; D005909:Glioblastoma / Q000235:genetics* / Q000473:pathology / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D012333:RNA, Messenger