Abstract 5197

Introduction

Diffuse large B cell lymphoma (DLBCL) is an aggressive malignancy that accounts for nearly 40% of all lymphoid tumors. Both miR-155 and miR-146a expression levels are suggested to be regulated by NF-KB expression in DLBCL. In present study, the expression of miR-155 and miR-146a were investigated to evaluate the prognosis in DLBCL patients.

Patients and Methods

The expression levels of miR-155 and miR-146a in formalin-fixed/paraffin-embedded tissue of patients with DLBCL (n=50) have been compared with reactive hyperplasia lymphoid nodes (n=20) by using real-time polymerase chain reaction. Clinical characters of patients such as LDH, β2-MG, International Prognostic Index (IPI), ECOG score and c-myc expression levels have also been investigated.

Results

1) The expression levels of miR-155 and miR-146a were significantly higher in DLBCL patients than control (P<0.001). (Fig 1)

2) The expression levels of miR-155 and miR-146a were different between germinal center B-cell like DLBCL (GCB-DLBCL) and activated B-cell-like DLBCL (ABC-DLBCL), but the difference had no significance (P>0.05).

3) There was correlation between the expression of miR-155 and miR-146a in DLBCL patients (r =0.639, P<0.001).

4) There was positive correlation in the expression of miR-146a with LDH, β2-MG, IPI, ECOG score and c-myc expression levels in DLBCL patients.

5) Lower expression levels of miR-155 and miR-146a were found to be associated with high complete remission (CR) rate and overall response (OR) rate in DLBCL patients (P<0.05).

6) Lower expression levels of miR-146a in DLBCL patients were only associated with better 5 years progression free survival (5y-PFS) (P=0.044), but lower expression levels of miR-155 in DLBCL patients were associated with better 5y-PFS (P=0.013) and 5 years overall survival (5y-OS) (P=0.007).

7) Multivariate analysis using a Cox proportional hazard model confirmed that either miR-155 or miR-146a was the independent predictor. (For miR-155 5y-PFS, Hazards ratio 0.260, 95% CI, 0.058–0.801; for miR-146a 5y-PFS, Hazards ratio 0.251, 95% CI, 0.068–0.922)

8) Compared to CHOP protocol, the higher miR-155 expression level patients who chose R-CHOP protocol for treatment achieved better 3y-PFS and 3y-OS (P<0.05).

Conclusions

The expression levels of miR-155 and miR-146a were higher in DLBCL patients. Moreover, high expressions of these two microRNAs were associated with the disease progression. Patients with higher miR-155 expression levels may be benefit from the protocol including Rituximab.

Disclosures:

No relevant conflicts of interest to declare.

Author notes

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Asterisk with author names denotes non-ASH members.

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