Exosomes are extracellular vesicles characterized by their size, source, release mechanism and contents. MicroRNAs (miRNAs) are single stranded non-coding RNAs transcribed from DNA. Exosomes and miRNAs are widespread in eukaryotic cells, especially in mesenchymal stem cells (MSCs). MSCs are used for tissue regeneration, and also exert paracrine, anti-inflammatory and immunomodulatory effects. However, the use of MSCs is controversial, especially in the presence or after the remission of a tumor, due to their secretion of growth factors and their migration ability. Instead of intact MSCs, MSC-derived compartments or substances could be used as practical tools for diagnosis, follow up, management and monitoring of diseases. Herein, we discuss some aspects of exosomal miRNAs derived from MSCs in the progression, diagnosis and treatment of various diseases.

Gene therapy as a therapeutic approach has been the dream for many scientists around the globe. Many strategies have been proposed and applied for this purpose, yet the void for a functional safe method is still apparent. Since most of the diseases are caused by undesirable upregulation (oncogenes) or downregulation (tumor suppressor genes) of genes, major gene therapy's techniques affect gene expression. Most of the methods are used in post-transcriptional level such as RNA inhibitory (RNAi) and splice-switching oligonucleotides (SSOs). RNAi blocks messenger RNA (mRNA) translation by mRNA degradation or interruption between attachments of mRNA with ribosomes' subunits. However, one of the novel methods is the usage of transcription factor targeted decoys. DNA decoys are the new generation of functional gene downregulatory oligonucleotides which compete with specific binding sites of transcription factors. Considering the exponential growth of this technique in both in vitro and in vivo studies, in this paper, we aim to line out the description, design, and application of decoys in research and therapy.

No abstract