PMC

miRNAs function as both tumor suppressor (including metastasis suppressor miRNA), and oncogene in breast cancer (For the details, see Text).

Biological and cellular functions of miRNAs. miRNAs subserve multiple fundamental biological roles. Various miRNAs may interact with thousands of different mRNA targets. Post-transcriptional RNA editing may change mRNA target specificity (For the details, see Text).

Modes of gene regulation by miRNAs. Diverse role of miRNAs, such as mRNA degradation, inhibition of translation, histone modification, and DNA methylation. miRNAs not only regulate gene expression at the post-transcriptional level, but they are also capable of modifying transcription (For the details, see Text).

MicroRNAs are altered or induced by environmental chemicals, drugs and dietary components through epigenetic mechanisms and genetic polymorphisms including protein or miRNA genes. Dietary components potentially influence fundamental cellular processes involved in carcinogenesis and psychiatric disorders, including apoptosis, cell cycle control, angiogenesis, inflammation and DNA repair. These alteration can be caused by various mechanisms, including deletion, amplifications or mutations involving miRNA loci, epigenetic silencing or dysregulation of transcription factors that target specific mRNA. Targeting miRNAs may provide insight into the common and unique pathways and mechanisms of the treatment. Elucidating more miRNAs and predicted targets may reveal novel therapies that modify plasticity cascades to restore function (For the details, see Text).