Antineoplastic effects of liposomal siRNA treatment targeting BLIMP1/PRDM1 in primary effusion lymphoma

RNA interference (RNAi) has been suggested to represent a promising therapeutic approach in different disease settings. Primary effusion lymphoma (PEL) is a plasmablastic lymphoma consistently expressing B lymphocyte-induced maturation protein 1 (Blimp-1), a pivotal transcriptional regulator during terminal differentiation of B cells into plasma cells. Here we report, for the first time, that transient knockdown of the BLIMP1 gene (also known as PR Domain Containing 1 with ZNF Domain, or PRDM1) using small interfering RNA (siRNA) delivered by liposomes, induced remarkable killing in PEL cell lines. Furthermore, in a murine model of PEL, significantly prolonged survival was achieved by intraperitoneal treatment with such anti-BLIMP1 lipoplexes, while no vector-induced toxicity was observed. This effective and safe RNAi strategy, based on liposomal siRNA targeting a master transcription factor of post-germinal center B cells, may indeed be a potential treatment against plasmablastic lymphoma