Clinical significance of enhancer of zeste homolog 2 expression in colorectal cancer cases.
BACKGROUND
Enhancer of zeste homolog 2 (EZH-2) is a polycomb group (PcG) protein, and the clinical significance of this protein has not yet been determined in colorectal cancer (CRC) cases. Recently, investigations of CRC cases have focused on the interaction between EZH-2 and histone deacetylase-1 (HDAC-1).


METHODS
We performed real time RT-PCR to evaluate the expression of EZH-2 mRNA quantitatively in tumour and normal tissue samples from 61 cases of CRC. The expression of HDAC-1 in CRC cases was also examined in order to compare its levels with those of EZH-2.


RESULTS
Among the CRC cases, 32 patients whose tumour tissue showed overexpression of EZH-2 also had a significantly worse prognosis than did 29 patients whose tumour tissue showed low EZH-2 expression (p<0.05). In addition, a significant correlation between EZH-2 and HDAC-1 expression was observed in 61 CRC cases (p<0.05). Moreover, 20 cases of both high EZH-2 and high HDAC-1 expression showed poor prognoses than did 19 cases in which there was low EZH-2 and low HDAC-1 expression (p<0.05).


CONCLUSIONS
The abundant expression of EZH-2 in CRC cases indicated that EZH-2 may be an oncogene and a prognostic marker for CRC cases. We discovered there was concordant expression of HDAC-1 with EZH-2 in clinical CRC cases, in addition to the fact that higher expression levels of both genes predicted a poor prognosis.
Mimori
K
K
Department of Surgery, Medical Institute of Bioregulation, Kyushu University, 4546 Tsrumihara, Beppu 874-0838, Japan.
Ogawa
K
K
Okamoto
M
M
Sudo
T
T
Inoue
H
H
Mori
M
M
D015179:Colorectal Neoplasms / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D029721:Drosophila Proteins; D004742:Enhancer Elements, Genetic; D006655:Histone Deacetylases / Q000378:metabolism; D006801:Humans; D011379:Prognosis; D016016:Proportional Hazards Models; D020133:Reverse Transcriptase Polymerase Chain Reaction
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C060849:z protein, Drosophila; D006655:Histone Deacetylases