Expression of exportin-1 in diffuse large B-cell lymphoma: immunohistochemistry and TCGA analyses

Int J Clin Exp Pathol. 2018 Dec 1;11(12):5547-5560. eCollection 2018.

Abstract

Exportin-1 (XPO1) is an essential nuclear export receptor that is involved in the pathogenesis of multiple tumors. However, the role of XPO1 in diffuse large B-cell lymphoma (DLBCL) requires clarification. This study aims to detect XPO1 expression in DLBCL and to explore its relationships with clinicopathologic parameters and prognoses.

Methods: A total of 131 cases of DLBCL and 30 cases of reactive lymphoid hyperplasia were selected for immunohistochemistry to examine XPO1 expression and analyze the relationships of XPO1 expression with clinicopathologic parameters and prognosis. DLBCL datasets downloaded from The Cancer Genome Atlas (TCGA) were used to analyze the mutations, expressions, and clinical values of XPO1 in DLBCL.

Results: XPO1 expression was markedly upregulated in DLBCL compared to the reactive lymphoid hyperplasia group (χ2 = 10.734, P = 0.001). High XPO1 expression was associated with an advanced clinical stage (χ2 = 4.036, P = 0.045) and a risky International Prognostic Index (IPI) score (χ2 = 5.301, P = 0.025). Moreover, high XPO1 expression was associated with a lower overall survival rate compared with low expression (P = 0.043). XPO1 was an independent prognostic factor for DLBCL (risk ratio, RR = 3.772, P = 0.006). Furthermore, XPO1 overexpression in DLBCL was correlated with a high IPI score (P = 0.024) in TCGA datasets.

Conclusion: High XPO1 expression in DLBCL was related to an advanced clinical stage, poor IPI score, and poor prognosis. Thus, XPO1 may be useful for condition identification and prognostic assessment.

Keywords: Diffuse large B-cell lymphoma; clinicopathological significance; exportin-1; prognosis.