title: Colorectal adenoma to carcinoma progression is accompanied by changes in gene expression associated with ageing, chromosomal instability, and fatty acid metabolism.
abstract: BACKGROUND
  Colorectal cancer develops in a multi-step manner from normal epithelium, through a pre-malignant lesion (so-called adenoma), into a malignant lesion (carcinoma), which invades surrounding tissues and eventually can spread systemically (metastasis). It is estimated that only about 5% of adenomas do progress to a carcinoma.
  
  
  OBJECTIVE
  The present study aimed to unravel the biology of adenoma to carcinoma progression by mRNA expression profiling, and to identify candidate biomarkers for adenomas that are truly at high risk of progression.
  
  
  METHODS
  Genome-wide mRNA expression profiles were obtained from a series of 37 colorectal adenomas and 31 colorectal carcinomas using oligonucleotide microarrays. Differentially expressed genes were validated in an independent colorectal gene expression data set. Gene Set Enrichment Analysis (GSEA) was used to identify altered expression of sets of genes associated with specific biological processes, in order to better understand the biology of colorectal adenoma to carcinoma progression.
  
  
  RESULTS
  mRNA expression of 248 genes was significantly different, of which 96 were upregulated and 152 downregulated in carcinomas compared to adenomas. Classification of adenomas and carcinomas using the expression of these genes showed to be very accurate, also when tested in an independent expression data set. Gene-sets associated with ageing (which is related to senescence) and chromosomal instability were upregulated, and a gene-set associated with fatty acid metabolism was downregulated in carcinomas compared to adenomas. Moreover, gene-sets associated with chromosomal location revealed chromosome 4q22 loss and chromosome 20q gain of gene-set expression as being relevant in this progression.                                               CONCLUDING REMARK:                          These data are consistent with the notion that adenomas and carcinomas are distinct biological entities. Disruption of specific biological processes like senescence (ageing), maintenance of chromosomal instability and altered metabolism, are key factors in the progression from adenoma to carcinoma.
authors.affiliation: Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands. b.carvalho@vumc.nl
authors.forename: Beatriz
authors.initials: B
authors.lastname: Carvalho
authors.forename: Anke H
authors.initials: AH
authors.lastname: Sillars-Hardebol
authors.forename: Cindy
authors.initials: C
authors.lastname: Postma
authors.forename: Sandra
authors.initials: S
authors.lastname: Mongera
authors.forename: Jochim
authors.initials: J
authors.lastname: Terhaar Sive Droste
authors.forename: Askar
authors.initials: A
authors.lastname: Obulkasim
authors.forename: Mark
authors.initials: M
authors.lastname: van de Wiel
authors.forename: Wim
authors.initials: W
authors.lastname: van Criekinge
authors.forename: Bauke
authors.initials: B
authors.lastname: Ylstra
authors.forename: Remond J A
authors.initials: RJ
authors.lastname: Fijneman
authors.forename: Gerrit A
authors.initials: GA
authors.lastname: Meijer
mesh_terms: D000236:Adenoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000235:genetics*; D043171:Chromosomal Instability / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D030541:Databases, Genetic; D018450:Disease Progression; D015536:Down-Regulation / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D052138:Genes, Neoplasm / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D015203:Reproducibility of Results; D015854:Up-Regulation / Q000235:genetics
chemical_list: D005227:Fatty Acids