The role of exosomes contents on genetic and epigenetic alterations of recipient cancer cells

Exosomes, as a mediator of cell-to-cell transfer of genetic information, act an important role in intercommunication between tumor cells and their niche including fibroblasts, endothelial cells, adipocytes and monocytes. Several studies have shown that tumor cells can influence their neighboring cells by releasing exosomes. These exosomes provide signaling cues for stimulation, activation, proliferation and differentiation of cells. Exosomes contain mRNAs, microRNAs (miRNA), and proteins that could be transferred to target cells inducing genetic and epigenetic changes. By facilitating the horizontal transfer of bioactive molecules such as proteins, RNAs and microRNAs, they are now thought to have vital roles in tumor invasion and metastases, inflammation, coagulation, and stem cell renewal and expansion. The aim of this review article is to discuss the significance of exosome-mediated intercellular communication within the tumor biology

MicroRNA-mediated post-transcriptional regulation of epithelial to mesenchymal transition in cancer

Epithelial to mesenchymal transition (EMT) program participates in tissue repair, embryogenesis and numerous pathological conditions, particularly cancer progression and tumor metastasis. A highly complex and strongly controlled post-transcriptionally regulated network of microRNAs (miRNAs) regulates the EMT process. miRNAs are critical parts of the post-transcriptional regulation of gene expression. A set of miRNAs target multiple components of major signaling pathways and downstream effectors of EMT. miRNAs associated with this process are involved in controlling tumor progression and invasiveness either as oncogenes or as tumor suppressors. Since several miRNAs directly affect EMT-related master regulators, they have been discovered to have the potential to be used as biomarkers or targets in EMT-based pathological conditions such as cancer. Therefore, comprehensive understanding of miRNA-EMT correlation with tumor metastatic spread may provide improvements to diagnostic tools or therapeutics for cancer. This review summarizes our current knowledge about some of these important miRNAs and focuses on their specific roles in regulation of the EMT process in cancer