MicroRNAs (miRNAs) are endogenous small non-coding RNAs that regulate gene expression by binding to the 3´untranslated region of target mRNA, resulting in posttranscriptional gene silencing via mRNA degradation or translation inhibition. miRNAs are involved in many biological processes including carcinogenesis. They can act as oncogenes or tumor suppressors and their aberrant expressions are intimately linked with cancer development and progression. Therefore, miRNAs have been utilized as potential biomarkers for cancer diagnosis, prognosis, as well as cancer therapeutic targets. Recently, it has been demonstrated that dietary and natural chemopreventive agents exert their anticancer activities through the regulation of one or more miRNAs. In addition to expounding the latest findings of miRNAs in cancer, this review also discusses the recent efforts on the translational research of miRNAs, with an emphasis on natural products in the treatment of cancer.

MicroRNAs (miRNAs) are a category of small RNAs that constitute a new layer of complexity to gene regulation within the cell, which has provided new perspectives in understanding cancer biology. The deregulation of miRNAs contributes critically to the development and pathophysiology of a number of cancers. miRNAs have been found to participate in cell transformation and multiplication by acting as tumour oncogenes or suppressors; therefore, harnessing miRNAs may provide promising cancer therapeutics. Another major function of miRNAs is their activity as critical regulatory vehicles eliciting important regulatory processes in anti-tumour immunity through their influence on the development, differentiation and activation of various immune cells of both innate and adaptive immunity. This review aims to summarise recent findings focusing on the regulatory mechanisms of the development, differentiation, and proliferative aspects of the major immune populations by a diverse profile of miRNAs and may enrich our current understanding of the involvement of miRNAs in anti-tumour immunity.