title: The Expression of Toll-like Receptors in Normal Human and Murine Gastrointestinal Organs and the Effect of Microbiome and Cancer.
abstract: Toll-like receptors (TLRs) are innate immune receptors expressed in all parts of the alimentary tract. However, analyses comparing expression in different segments and data on germ-free animals are lacking. Alimentary tract cancers show increased TLR expression. According to the field effect concept, carcinogenetic factors induce subtle cancer predisposing alterations in the whole organ. We studied TLR1 to TLR9 expression in all segments of the alimentary tract from cancer patients' tumor-adjacent normal mucosa, healthy organ donors, and conventional and germ-free mice by using immunohistochemistry and quantitative PCR. All TLRs were expressed in all segments of the alimentary tract. Expression was most intensive in the small intestine in humans and conventional mice, but germ-free mice showed less expression in the small intestine. TLR expression levels were similar in cancer patients and organ donors. We provide systematic baseline data on the TLR expression in the alimentary tract. Normal epithelium adjacent to tumor seems to have similar TLR expression compared with healthy tissues suggesting absence of any field effect in TLR expression. Accordingly, specimens from cancer patients' normal tumor-adjacent tissue can be used as control tissues in immunohistochemical TLR studies in gastrointestinal cancer.
authors.affiliation: Departments of Pathology, University of Oulu, Oulu, Finland (HH, OH, JHK, KP, TJK)|Surgery, University of Oulu, Oulu, Finland (HH, OH, JHK, JS, PPL)|Medical Research Center Oulu, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)|Oulu University Hospital, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)
authors.forename: Heikki
authors.initials: H
authors.lastname: Huhta
authors.affiliation: Departments of Pathology, University of Oulu, Oulu, Finland (HH, OH, JHK, KP, TJK)|Surgery, University of Oulu, Oulu, Finland (HH, OH, JHK, JS, PPL)|Medical Research Center Oulu, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)|Oulu University Hospital, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)
authors.forename: Olli
authors.initials: O
authors.lastname: Helminen
authors.affiliation: Departments of Pathology, University of Oulu, Oulu, Finland (HH, OH, JHK, KP, TJK)|Surgery, University of Oulu, Oulu, Finland (HH, OH, JHK, JS, PPL)|Medical Research Center Oulu, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)|Oulu University Hospital, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)
authors.forename: Joonas H
authors.initials: JH
authors.lastname: Kauppila
authors.affiliation: Dentistry, University of Oulu, Oulu, Finland (TS)|Medical Research Center Oulu, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)|Oulu University Hospital, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)
authors.forename: Tuula
authors.initials: T
authors.lastname: Salo
authors.affiliation: Departments of Pathology, University of Oulu, Oulu, Finland (HH, OH, JHK, KP, TJK)
authors.forename: Katja
authors.initials: K
authors.lastname: Porvari
authors.affiliation: Surgery, University of Oulu, Oulu, Finland (HH, OH, JHK, JS, PPL)|Medical Research Center Oulu, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)|Oulu University Hospital, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)
authors.forename: Juha
authors.initials: J
authors.lastname: Saarnio
authors.affiliation: Surgery, University of Oulu, Oulu, Finland (HH, OH, JHK, JS, PPL)|Anatomy and Cell biology, University of Oulu, Oulu, Finland (PPL)|Medical Research Center Oulu, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)|Oulu University Hospital, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)
authors.forename: Petri P
authors.initials: PP
authors.lastname: Lehenkari
authors.affiliation: Departments of Pathology, University of Oulu, Oulu, Finland (HH, OH, JHK, KP, TJK)|Medical Research Center Oulu, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)|Oulu University Hospital, Oulu, Finland (HH, OH, JHK, TS, JS, PPL, TJK)
authors.forename: Tuomo J
authors.initials: TJ
authors.lastname: Karttunen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D004064:Digestive System / Q000378:metabolism* / Q000382:microbiology; D005260:Female; D000069196:Gastrointestinal Microbiome / Q000502:physiology*; D005770:Gastrointestinal Neoplasms / Q000378:metabolism*; D005856:Germ-Free Life; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism / Q000382:microbiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008875:Middle Aged; D009928:Organ Specificity; D013045:Species Specificity; D051193:Toll-Like Receptors / Q000378:metabolism*
chemical_list: D051193:Toll-Like Receptors
keywords: Toll-like receptor; alimentary tract; cancer; expression; germ-free mouse; mouse; organ donor; tumor-adjacent normal epithelium