Clinical significance of enhancer of zeste homolog 2 and histone deacetylases 1 and 2 expression in peripheral T‑cell lymphoma

Epigenetics serve a key role in peripheral T cell lymphoma (PTCL). The purpose of the present study was to investigate the clinical significance of enhancer of zeste homolog 2 (EZH2) and histone deacetylase 1 and 2 (HDAC1/2) expression in PTCL. A total of 82 patients were enrolled in the present study, including 43 with PTCL not otherwise specified (PTCL-NOS), 10 with angioimmunoblastic T-cell lymphoma (AITL), 14 with natural killer/T-cell lymphoma (NK/TCL) and 15 with anaplastic large cell lymphoma (ALCL). EZH2 and HDAC1/2 expression was detected by immunohistochemistry and any correlations between them were evaluated. Additionally, any correlations between EZH2 or HDAC1/2 expression and a number of clinicopathological characteristics were analyzed, and survival curves were created. Results revealed that 55.8% of patients with PTCL-NOS, 57.1% of patients with NK/TCL, 86.7% of patients ALCL and 50% of patients with AITL highly expressed HDAC1. Furthermore, 58.1% of patients with PTCL-NOS, 57.1% of patients with NK/TCL, 53.3% of patients with ALCL and 60% of patients with AITL highly expressed HDAC2. Additionally, 67.5% of patients with PTCL-NOS, 50% of patients with NK/TCL, 73.3% of patients with ALCL and 60% of patients with AITL highly expressed EZH2. EZH2 expression was significantly correlated with the presence of B symptoms, elevated LDH and elevated beta 2 microglobulin (B2M; P<0.05), and HDAC2 expression was significantly correlated with sex, advanced clinical stages, high international prognostic index scores and elevated B2M levels (P<0.05) in all the patients with PTCL. However, different subtypes of PTCL are correlated with different clinical characteristics. Patients with PTCL highly expressing EZH2 or HDAC2 exhibit a poorer overall survival rate. In conclusion, EZH2 and HDAC1/2 were frequently upregulated in patients with PTCL, and the patients with a higher EZH2 and HDAC2 expression usually exhibited a poorer survival rate. Therefore, EZH2 and HDAC2 may be prognostic markers in patients with PTCL, particularly in those with PTCL-NOS.