The role of miR-150-5p/E2F3/survivin axis in the pathogenesis of plasmablastic lymphoma and its therapeutic potential

Plasmablastic lymphoma (PBL) is an uncommon and aggressive B-cell lymphoma with a poor prognosis. Some studies have described genetic alterations in PBL, but its transcriptome has been scarcely studied and molecular mechanisms driving lymphomagenesis remain poorly understood. Our goal was to delineate transcriptomic profiles to identify potential biomarkers for novel targeted therapy in PBL. RNA sequencing uncovered an enrichment of cell cycle-related genes, including MYC and E2F targets, and genes involved in G2/M checkpoint in PBL. Microarray analyses discovered two microRNA expression signatures depending on the presence of MYC-translocation. Interestingly, miR-150-5p was downregulated, while E2F3 and BIRC5 (survivin), a cell cycle activator and anti-apoptotic regulator respectively, were upregulated. Increasing miR-150-5p in PBL-1 cells induced G1 cell cycle arrest, suppressed proliferation by transcriptionally repressing E2F3, and promoted apoptosis by downregulation of BIRC5. Interestingly, the miR-150-5p tumor suppressor activity was diminished in E2F3-knockdown cells. The combined inhibition of E2F3 and survivin attenuated lymphomagenesis in PBL cells and suppressed tumor growth in a chorioallantoic membrane (CAM)-derived xenograft model of PBL. Overall, our study highlights the pivotal role of the miR-150-5p/E2F3/survivin axis boosting PBL lymphomagenesis and unveils new therapeutic targets for this lymphoma.