Housekeeping genes in cancer: normalization of array data.
Biological maintenance of cells under variable conditions should affect gene expression of only certain genes while leaving the rest unchanged. The latter, termed "housekeeping genes," by definition must reflect no change in their expression levels during cell development, treatment, or disease state anomalies. However, deviations from this rule have been observed. Using DNA microarray technology, we report here variations in expression levels of certain housekeeping genes in prostate cancer and a colorectal cancer gene therapy model system. To highlight, differential expression was observed for ribosomal protein genes in the prostate cancer cells and beta-actin in treated colorectal cells. High-throughput differential gene expression analysis via microarray technology and quantitative PCR has become a common platform for classifying variations in similar types of cancers, response to chemotherapy, identifying disease markers, etc. Therefore, normalization of the system based on housekeeping genes, such as those reported here in cancer, must be approached with caution.
Khimani
Anis H
AH
PerkinElmer Life Sciences, Boston, MA, USA.
Mhashilkar
Abner M
AM
Mikulskis
Alvydas
A
O'Malley
Michael
M
Liao
Jennifer
J
Golenko
Eva E
EE
Mayer
Pat
P
Chada
Sunil
S
Killian
Jeffrey B
JB
Lott
Steven T
ST
D000465:Algorithms; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D002138:Calibration; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling / Q000379:methods* / Q000592:standards; D006801:Humans; D019169:Jurkat Cells; D008297:Male; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods* / Q000592:standards; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins