The application of nanoparticles in delivering small RNAs for cancer therapy.

Small molecular RNAs, including microRNA (miRNA) and small interfering RNA (siRNA), participate in the regulation of gene expression. As powerful regulators, miRNAs, take part in posttranscriptional regulation of gene expression and play important roles in the diagnosis and treatment of cancer. Meanwhile, siRNA can induce sequence-specific gene silencing, thus being able to inhibit tumorigenesis by suppressing the expression of their targeted proto-oncogenes. Small RNAs (including naked miRNAs and siRNAs) are easily degraded by circulating RNAase, which can be retarded through the package of nanoparticles. Therefore, nanoparticles help tumor therapy by regulating targeted genes of small RNAs. Here, we reviewed the effects of small RNAs on gene expression; the advantages, disadvantages, and targeted modification of nanoparticles as carriers transporting small RNAs; and the application of nanocarriers delivering small RNA for cancer-targeted therapy.