Tumor-secreted microRNAs act as intercellular communication mediators to manipulate the host immune system

Tumor cells influence their environment by releasing various substances such as cytokines and chemokines. Intensive studies over the past several years have demonstrated that microvesicles (MVs) secreted by tumor cells contain proteins, mRNAs, and microRNAs (miRNAs) that play important roles in intercellular crosstalk. We recently reported an exciting finding that tumor cells can actively manipulate the host immune response via secreting an important oncomir, miR-214, through a pathway involving MVs. As an extension of this finding, we showed that the delivery of miR-214 antisense oligonucleotides (ASOs) via MVs can significantly inhibit tumor-induced immune escape and tumor growth, which provides a novel, effective approach for tumor treatment.