title: Mutations in the MYB intron I regulatory sequence increase transcription in colon cancers.
abstract: Although MYB overexpression in colorectal cancer (CRC) is known to be a prognostic indicator for poor survival, the basis for this overexpression is unclear. Among multiple levels of MYB regulation, the most dynamic is the control of transcriptional elongation by sequences within intron 1. The authors have proposed that this regulatory sequence is transcribed into an RNA stem-loop and 19-residue polyuridine tract, and is subject to mutation in CRC. When this region was examined in colorectal and breast carcinoma cell lines and tissues, the authors found frequent mutations only in CRC. It was determined that these mutations allowed increased transcription compared with the wild type sequence. These data suggest that this MYB regulatory region within intron 1 is subject to mutations in CRC but not breast cancer, perhaps consistent with the mutagenic insult that occurs within the colon and not mammary tissue. In CRC, these mutations may contribute to MYB overexpression, highlighting the importance of noncoding sequences in the regulation of key cancer genes.
authors.affiliation: Peter MacCallum Cancer Center, East Melbourne and Department of Pathology, The University of Melbourne, Australia.
authors.forename: Honor
authors.initials: H
authors.lastname: Hugo
authors.forename: Alina
authors.initials: A
authors.lastname: Cures
authors.forename: Nirosha
authors.initials: N
authors.lastname: Suraweera
authors.forename: Yvette
authors.initials: Y
authors.lastname: Drabsch
authors.forename: Damian
authors.initials: D
authors.lastname: Purcell
authors.forename: Theo
authors.initials: T
authors.lastname: Mantamadiotis
authors.forename: Wayne
authors.initials: W
authors.lastname: Phillips
authors.forename: Alex
authors.initials: A
authors.lastname: Dobrovic
authors.forename: Gabriella
authors.initials: G
authors.lastname: Zupi
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Gonda
authors.forename: Barry
authors.initials: B
authors.lastname: Iacopetta
authors.forename: Robert G
authors.initials: RG
authors.lastname: Ramsay
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology; D004260:DNA Repair / Q000235:genetics; D016762:Genes, fos; D020570:Genes, myb; D006801:Humans; D007438:Introns; D018895:Microsatellite Repeats; D009154:Mutation; D009690:Nucleic Acid Conformation; D011071:Poly T / Q000235:genetics; D018807:Polymorphism, Single-Stranded Conformational; D050436:Regulatory Elements, Transcriptional / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D020413:3' Untranslated Regions; D011071:Poly T