Delivery of a Modified mRNA Encoding IL-22 Binding Protein (IL-22BP) for Colon Cancer Gene Therapy

As an alternative form of genetic material, mRNA lacks a CpG island and can function without crossing the nuclear membrane. These properties make mRNA less of a potential immune stimulant than plasmid DNA. Therefore, chemically modified mRNA is an effective alternative to plasmid DNA for gene therapy. In this study, cationic liposomes were used as a vector to transport mRNA complexes that had been compressed using protamine and to obtain high mRNA transport and expression efficiency. The liposome-protamine-IL-22BP mRNA complex can strongly inhibit the growth of C26 tumour cells by inducing apoptosis, inhibiting tumour angiogenesis and increasing the number of immune cells that infiltrate the tumour microenvironment. The obvious tumour regression and safety of this approach were observed in peritoneal metastasis and subcutaneous xenograft models. The antitumour effect of the liposome protamine mRNA complex was as good as that for a plasmid DNA complex, and demonstrated the potential for mRNA-based gene therapy.