[Expression and Prognostic Significance of H3K27 Trimethylation Protein in DLBCL]

To investigate the expression and prognostic effect of H3K27 trimethylation protein (H3K27me3) in diffuse large B-cell lymphoma(DLBCL).

A total of 102 DLBCL patients from Fujian Provincial Cancer Hospital were enrolled in this study. No therapy had been given before specimen collection. Tissue microarray(TMA) technique and immunohistochemistry(IHC) method were used for H3K27me3 immunostaining. Clinicopathologic and suvival data were carefully collected. The association between tested markers, clinicopathologic characteristics and prognosis were evaluated. Survival rates were analyzed by the Kaplan-Meier method, and prognostic factor were analyzed by the Cox proportional hazards model, the relation of different expression levels with clinical feature and prognosis of patients was compared.

The quality of TMA was perfect and meet the standard of analysis. Among all DLBCL patients, 59.8% were characterized with high expression of H3K27me3, correlated with age, ECOG≥2, extranodular disease number≥2, elevation of LDH, medium-high risk IPI. Patients with high H3K27me3 expression manifested that the complete remission rate(CR) and overall remission rate (OR) were lower than those of patients with low expression, i.e., 20% vs 57.5% and 41.8% vs 90%, respectively (P<0.001). In addition, patients with high H3K27me3 expression showed shorter median survival time, i.e., 21.5 mon (P<0.0001). Multivariate analysis indicated that H3K27me3 was an independent risk factor for DLBCL patients (P=0.007).

TMA technique is valid for the construction of DLBCL tissue chips. Patients with high expression of H3K27me3 indicates little response to treatment, worse outcome and shorter overall survival. The detection of H3K27me3 expression possesses a certain clinical value for prediction of DLBCL outcome.