Selection of optimal sites for TGFB1 gene silencing by chitosan-TPP nanoparticle-mediated delivery of shRNA.

Most human tumors produce high levels of TGF-beta1, whose autocrine and paracrine actions promote tumor cell invasiveness and metastasis. Currently, many experimental therapies that target TGFB1 have utilized antisense DNA or RNA interference (RNAi). Despite the great potential of RNAi, the selection of effective target sites and proper delivery systems for short hairpin RNA (shRNA) remains a significant issue. Here, we used chitosan nanoparticle-mediated delivery of a shRNA-expressing vector to inhibit TGFB1 expression in the human rhabdomyosarcoma cell line RD. Knockdown of TGFB1 by shRNA resulted in a decrease in RD cell growth in vitro and tumorigenicity in nude mice. The efficiency of TGFB1 gene silencing varied with the selection of targeting sites. These data suggest that chitosan nanoparticle-mediated delivery of an shRNA produces efficient TGFB1 knockdown in rhabdomyosarcoma cells and may be a method of choice for shRNA delivery for gene therapy.