title: Human endogenous retrovirus K (HML-2) elements in the plasma of people with lymphoma and breast cancer.
abstract: Actively replicating endogenous retroviruses entered the human genome millions of years ago and became a stable part of the inherited genetic material. They subsequently acquired multiple mutations, leading to the assumption that these viruses no longer replicate. However, certain human tumor cell lines have been shown to release endogenous retroviral particles. Here we show that RNA from human endogenous retrovirus K (HERV-K) (HML-2), a relatively recent entrant into the human genome, can be found in very high titers in the plasma of patients with lymphomas and breast cancer as measured by either reverse transcriptase PCR or nucleic acid sequence-based amplification. Further, these titers drop dramatically with cancer treatment. We also demonstrate the presence of reverse transcriptase and viral RNA in plasma fractions that contain both immature and correctly processed HERV-K (HML-2) Gag and envelope proteins. Finally, using immunoelectron microscopy, we show the presence of HERV-K (HML-2) virus-like particles in the plasma of lymphoma patients. Taken together, these findings demonstrate that elements of the endogenous retrovirus HERV-K (HML-2) can be found in the blood of modern-day humans with certain cancers.
authors.affiliation: University of Michigan Medical Center, 5220 MSRB III, 1150 West Medical Center Drive, Ann Arbor, MI 48109-5640, USA.
authors.forename: Rafael
authors.initials: R
authors.lastname: Contreras-Galindo
authors.forename: Mark H
authors.initials: MH
authors.lastname: Kaplan
authors.forename: Philippe
authors.initials: P
authors.lastname: Leissner
authors.forename: Thibault
authors.initials: T
authors.lastname: Verjat
authors.forename: Ilaria
authors.initials: I
authors.lastname: Ferlenghi
authors.forename: Fabio
authors.initials: F
authors.lastname: Bagnoli
authors.forename: Fabiola
authors.initials: F
authors.lastname: Giusti
authors.forename: Michael H
authors.initials: MH
authors.lastname: Dosik
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Hayes
authors.forename: Scott D
authors.initials: SD
authors.lastname: Gitlin
authors.forename: David M
authors.initials: DM
authors.lastname: Markovitz
mesh_terms: D001943:Breast Neoplasms / Q000097:blood / Q000821:virology*; D016022:Case-Control Studies; D003287:Contrast Media / Q000494:pharmacology; D020077:Endogenous Retroviruses / Q000235:genetics*; D006801:Humans; D008223:Lymphoma / Q000097:blood / Q000821:virology*; D016253:Microscopy, Immunoelectron; D012367:RNA, Viral / Q000097:blood*; D012074:Remission Induction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic; D014283:Triiodobenzoic Acids / Q000494:pharmacology
chemical_list: D003287:Contrast Media; D012367:RNA, Viral; D014283:Triiodobenzoic Acids; C044834:iodixanol