Common denominator genes that distinguish colorectal carcinoma from normal mucosa.
OBJECTIVE
Microarray technology has been used by a growing number of investigators and several studies have been published that list hundreds of genes differentially expressed by colorectal carcinoma (CRC) and normal mucosa (MC). On the basis of our own and other investigators' microarray data, our goal was to identify a common denominator gene cluster distinguishing CRC from MC.


METHODS
Thirty GeneChips (HG-U133A, Affymetrix) were hybridized, 20 with RNA of CRC stages I-IV (UICC) and 10 with MC. Expression signals showing at least a 4-fold difference between CRC and MC (p<0.01) were identified as differentially expressed. In addition, in our integrative data analysis approach only those genes whose expression was altered simultaneously in at least 2 of 5 recently published studies were subjected to an unsupervised hierarchical cluster analysis.


RESULTS
We detected 168 up- and 283 down-regulated genes in CRC relative to MC. Twenty-three genes were filtered from the five articles reviewed. An unsupervised hierarchical cluster analysis of these 23 genes confirmed the high specificity of these genes to differentiate between CRC and MC in our microarray data.


CONCLUSIONS
Colorectal cancer and mucosa could be clearly separated by 23 genes selected for being differentially expressed more than once in a recent literature review. These genes represent a common denominator gene cluster that can be used to distinguish colorectal MC from CRC.
Croner
Roland S
RS
Department of Surgery, University of Erlangen, Krankenhausstrasse 12, 91054 Erlangen, Germany. Roland.Croner@chir.imed.uni-erlangen.de
Foertsch
Thomas
T
Brueckl
Wolfgang M
WM
Guenther
Klaus
K
Siebenhaar
Renate
R
Stremmel
Christian
C
Matzel
Klaus E
KE
Papadopoulos
Thomas
T
Kirchner
Thomas
T
Behrens
Jürgen
J
Klein-Hitpass
Ludger
L
Stuerzl
Michael
M
Hohenberger
Werner
W
Reingruber
Bertram
B
D002277:Carcinoma / Q000175:diagnosis* / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D015536:Down-Regulation; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology*; D020411:Oligonucleotide Array Sequence Analysis; D012680:Sensitivity and Specificity; D015854:Up-Regulation