Sequential gene expression changes in cancer cell lines after treatment with the demethylation agent 5-Aza-2'-deoxycytidine.
BACKGROUND
5-Aza-2'-deoxycytidine (5-AzaC) is known well for its demethylation effect and is a promising anticancer agent. However, to the authors' knowledge, serial changes in gene expression over time after 5-AzaC treatment have not been studied to date. To clarify the categories of genes that are up-regulated or down-regulated after 5-AzaC treatment, the authors surveyed the genes that had expression levels changed by 5-AzaC treatment in 6 hepatoma cell lines (Hep3B, HLE, Huh7, HepG2, PLC/PRF/5, and Huh6).


METHODS
Cell lines were grown in medium that contained 1 microM of 5-AzaC. Changes in messenger RNA levels were monitored from 24 hours up to 120 hours after 5-AzaC treatment using an in-house microarray that consisted of 4608 combinational DNAs. Using clustering analysis to identify the genes that had gradually changed expression levels and to exclude the substantial experimental noise by microarray analysis, the authors focused on 206 up-regulated genes and 248 down-regulated genes.


RESULTS
According to their functional characterization, genes that were involved in the cytoskeleton and the extracellular matrix were enriched significantly in the up-regulated genes. Conversely, genes that were involved in metabolism were enriched significantly in the down-regulated genes.


CONCLUSIONS
The current results demonstrated that 5-AzaC can regulate the expression of groups of genes with characteristic functions.
Arai
Makoto
M
Department of Medicine and Clinical Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan.
Yokosuka
Osamu
O
Hirasawa
Yuichi
Y
Fukai
Kenichi
K
Chiba
Tetsuhiro
T
Imazeki
Fumio
F
Kanda
Tatsuo
T
Yatomi
Mari
M
Takiguchi
Yuichi
Y
Seki
Naohiko
N
Saisho
Hiromitsu
H
Ochiai
Takenori
T
D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D019175:DNA Methylation / Q000187:drug effects; D015254:DNA Modification Methylases / Q000037:antagonists & inhibitors; D000077209:Decitabine; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000187:drug effects
D004791:Enzyme Inhibitors; D009363:Neoplasm Proteins; D000077209:Decitabine; D015254:DNA Modification Methylases; D001374:Azacitidine