Does the increase of exosomal microRNAs reflect an activated immune system in melanoma?

One of the new classes of potential cancer biomarkers are microRNAs. MicroRNAs are non-coding RNAs that suppress the translation of their target mRNAs by binding to the 3’ untranslated region³. On the one hand, melanoma-derived exosomes are discussed as vesicles for degradation of anti-tumor microRNAs. On the other hand, exosomal microRNAs might be active in recipient cells4, e.g., by repressing anti-tumorigenic immune responses. To investigate these possibilities, we profiled the microRNA content of exosomes from melanoma cell lines and plasma of melanoma patients. Informed consent was collected according to guidelines for medical and research ethics.