Clinical significance of enhancer of zeste homolog 2 expression in colorectal cancer cases

Introduction. 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 cotorectal cancer (CRC) cases. Recently, investigations of CRC cases have focused on the interaction between EZH-2 and histone deacetylase-1 (HDAC- 1). Patients and methods. We performed real time RT-PCR to evaluate the expression of EZH-2 mRNA quantitativety 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 tow EZH-2 and low HDAC-1 expression (p < 0.05). Conclusion. 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. (c) 2004 Etsevier Ltd. All rights reserved.