[Clinical Significance of XPO1 High Expression in Diffuse Large B-Cell Lymphoma and Its Mechanism]

To explore the expression and clinical significance of XPO1 in newly diagnosed adult diffuse large B-cell lymphoma (DLBCL), and further investigate its functional mechanism.

Immunohistochemical testing was conducted for XPO1 expression in 93 cases of DLBCL and 30 cases of reactive lymphoid hyperplasia. A risk model was construed to find survival related genes in DLBCL patients. Cell proliferation, apoptosis, and cell cycle assays were performed to explore the effect of XPO1 inhibitor (KPT-8602) and XPO1 knockdown. Differential expression gene (DEG) was examined based on the transcriptomes.

The expression of XPO1 in DLBCL patients was higher than that of the controls. Compared with XPO1 low-expression group, XPO1 high-expression group had a worse prognosis. The constructed risk model indicated that XPO1 and 14 genes in nucleocytoplasmic transport pathway (NTP) might be potential prediction marker of adverse outcome in DLBCL. Moreover, KPT-8602 as well as the XPO1 knockdown could inhibit cell proliferation, promote apoptosis, and induce cell cycle arrest in two DLBCL cell lines, Farage and SU-DHL-4. Based on the gene expression profiling in the datasets of DLBCL, patients were classified into XPO1 high and XPO1 low expression groups, and the MYBL1 was identified as the down-stream effector of XPO1. Inhibiting the function of XPO1 or reducing its expression can significantly decrease the expression of MYBL1 Conclusion: XPO1 is highly expressed in DLBCL, which is associated with poor prognosis. The oncogenic roles of the new XPO1/MYBL1 signaling are identified in DLBCL and XPO1 inhibitor may be a potential option for newly-diagnosed DLBCL patients.