title: Distinguishing right from left colon by the pattern of gene expression.
abstract: Distinct epidemiological and clinicopathological characteristics of colorectal carcinomas (CRCs) based on their anatomical location suggest different risk factors and pathways of transformation associated with proximal and distal colon carcinogenesis. These differences may reflect distinct biological characteristics of proximal and distal colonic mucosa, acquired in embryonic or postnatal development, that determine a differential response to uniformly distributed environmental factors. Alternatively, the differences in the epidemiology of proximal and distal CRCs could result from the presence of different procarcinogenic factors in the ascending versus descending colon, acting on cells with either similar or distinct biological characteristics. We applied cDNA microarray technology to explore the possibility that mucosal epithelium from adult proximal and distal colon can be distinguished by their pattern of gene expression. In addition, gene expression was studied in fetal (17-24 weeks gestation) proximal and distal colon. More than 1000 genes were expressed differentially in adult ascending versus descending colon, with 165 genes showing >2-fold and 49 genes showing >3-fold differences in expression. With almost complete concordance, biopsies of adult colonic epithelium can be correctly classified as proximal or distal by gene expression profile. Only 87 genes were expressed differently in ascending and descending fetal colon, indicating that, although anatomically relevant differences are already established in embryonic colon, additional changes in gene expression occur in postnatal development.
authors.affiliation: Genetics Branch, Center for Cancer Research, National Cancer Institute (NCI), Bethesda, Maryland 20892, USA.
authors.forename: Oleg K
authors.initials: OK
authors.lastname: Glebov
authors.forename: Luz M
authors.initials: LM
authors.lastname: Rodriguez
authors.forename: Kenneth
authors.initials: K
authors.lastname: Nakahara
authors.forename: Jean
authors.initials: J
authors.lastname: Jenkins
authors.forename: Janet
authors.initials: J
authors.lastname: Cliatt
authors.forename: Casey-Jo
authors.initials: CJ
authors.lastname: Humbyrd
authors.forename: John
authors.initials: J
authors.lastname: DeNobile
authors.forename: Peter
authors.initials: P
authors.lastname: Soballe
authors.forename: Richard
authors.initials: R
authors.lastname: Simon
authors.forename: George
authors.initials: G
authors.lastname: Wright
authors.forename: Patrick
authors.initials: P
authors.lastname: Lynch
authors.forename: Sherri
authors.initials: S
authors.lastname: Patterson
authors.forename: Henry
authors.initials: H
authors.lastname: Lynch
authors.forename: Steven
authors.initials: S
authors.lastname: Gallinger
authors.forename: Aby
authors.initials: A
authors.lastname: Buchbinder
authors.forename: Gary
authors.initials: G
authors.lastname: Gordon
authors.forename: Ernest
authors.initials: E
authors.lastname: Hawk
authors.forename: Ilan R
authors.initials: IR
authors.lastname: Kirsch
mesh_terms: D000328:Adult; D003106:Colon / Q000196:embryology; D044682:Colon, Ascending; D044683:Colon, Descending; D007839:Functional Laterality; D005784:Gene Amplification; D015870:Gene Expression / Q000502:physiology*; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D012313:RNA / Q000032:analysis
chemical_list: D012313:RNA