Overexpression of CDCA2 in Diffuse Large B-Cell Lymphoma Promotes Cell Proliferation and Bortezomib Sensitivity

Numerous clinical trials have attempted to improve first-line R-CHOP treatment of diffuse large B-cell lymphoma (DLBCL) through the addition or substitution of drugs. The REMoDL-B trial, testing the addition of bortezomib (RB-CHOP), revealed that ABC and molecular high-grade DLBCL patients benefit from bortezomib. The aim of this study was to achieve a better understanding of the bortezomib response in DLBCL through a functional investigation of clinically identified markers. A retrospective analysis of transcriptional and clinical data from the REMoDL-B trial was conducted to identify genes associated with bortezomib response, identifying CDCA2. DLBCL patients with high expression of CDCA2 had a superior survival outcome when treated with RB-CHOP in comparison to R-CHOP, whereas no difference in outcome was observed for patients with low CDCA2. Moreover, CDCA2 was found to be overexpressed in DLBCL compared to non-malignant tissue, and to have higher levels in GCB and MYC/BCL2 double-expressor patients. Functional in vitro and in vivo studies revealed that knockout of CDCA2 decreased DLBCL cell proliferation and a bortezomib dose-response analysis showed less sensitivity in CDCA2 knockout cells compared to control cells. This study shows that DLBCL patients with high CDCA2 expression benefitted from the addition of bortezomib to R-CHOP and functional studies documented a direct impact of CDCA2 on the bortezomib response in DLBCL cells.