RNA-based therapeutic strategies for cancer

Recent progress in the field of RNA therapeutics has highlighted the potential of using RNA-based strategies for the treatment of human cancer. Emerging technologies such as small interfering RNA (siRNA) to trigger RNA interference (RNAi) and catalytic RNA molecules, called ribozymes, are being developed to modulate expression of genes to either block tumourigenesis itself, inhibit tumour growth or prevent metastasis. Delivery of mRNA or vectors based on positive-strand RNA viruses such as alpha viruses, picornaviruses and flaviviruses have also found applications in the development of cancer vaccines and for apoptosis of tumour cells. These approaches should help overcome some of the drawbacks of viral vectors used in the majority (similar to 60%) of clinical trials for cancer gene therapy, including potential malignant transformation due to insertional mutagenesis with retroviral delivery and preexisting immune responses to adenoviral proteins. In this review, the advantages and disadvantages of RNA-based therapeutic strategies and their potential use in cancer treatments will be compared.