MicroRNAs (
miRNAs), small non-coding RNAs, can regulate post-transcriptional gene expressions and silence a broad set of target genes.
miRNAs, aberrantly expressed in
cancer cells, play an important role in modulating gene expressions, thereby regulating downstream signaling pathways and affecting
cancer formation and progression. Oncogenes or tumor suppressor genes regulated by
miRNAs mediate cell cycle progression, metabolism, cell death, angiogenesis,
metastasis and immunosuppression in
cancer. Recently,
miRNAs have emerged as therapeutic targets or tools and
biomarkers for diagnosis and
therapy monitoring in
cancer. Since
miRNAs can regulate multiple
cancer-related genes simultaneously, using
miRNAs as a therapeutic approach plays an important role in
cancer therapy. However, one of the major challenges of
miRNA-based
cancer therapy is to achieve specific, efficient and safe systemic delivery of therapeutic
miRNAs in vivo. This review discusses the key challenges to the development of the carriers for
miRNA-based
therapy and explores current strategies to systemically deliver
miRNAs to
cancer without induction of toxicity.