title: Exfoliated cells in stool: a source for reverse transcription-PCR-based analysis of biomarkers of gastrointestinal cancer.
abstract: Because the colonic mucosa is in direct contact with digesta, luminal exposure to potentially carcinogenic or chemopreventive agents may be important in colorectal carcinogenesis, independently of the effects of systemic exposure through the circulation. To date, few biomarkers for luminal exposure have been identified, and isolation of reasonably good quality fecal human RNA remains difficult. In this study, we assessed the yield and quality of RNA extracted from 10 human stool samples after storage with several commercially available preservatives compared with stool samples immediately frozen in liquid nitrogen. This study shows that careful design of primer pairs which amplify a short length of DNA is key to obtaining interpretable and reproducible results. Moreover, the use of commercially available RNA preservation kits enables investigators to collect usable fecal samples from large populations. Of all the preservative methods tested, RNAlater had the best performance in terms of overall quality, quantity, and level of genomic DNA contamination, and thus deserves further investigation.
authors.affiliation: Department of Internal Medicine, Wayne State University, Detroit, MI 48201, USA.
authors.forename: Ying Jie
authors.initials: YJ
authors.lastname: Yu
authors.forename: Adhip P N
authors.initials: AP
authors.lastname: Majumdar
authors.forename: Jordan M
authors.initials: JM
authors.lastname: Nechvatal
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Ram
authors.forename: Marc D
authors.initials: MD
authors.lastname: Basson
authors.forename: Lance K
authors.initials: LK
authors.lastname: Heilbrun
authors.forename: Ikuko
authors.initials: I
authors.lastname: Kato
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D005243:Feces / Q000166:cytology*; D005770:Gastrointestinal Neoplasms / Q000473:pathology*; D006801:Humans; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor