Delivering RNA through exosomes for cancer therapy

RNA is rapidly emerging as a pivotal therapeutic modality in oncology. Nonetheless, the successful delivery of RNA molecules into cells faces obstacles due to their large molecular weight, inherent negative charge, and susceptibility to degradation by RNase enzymes. In recent years, exosomes as RNA delivery vehicles have received increasing attention as an innovative approach to treat cancer. Exosomes offer distinct advantages in delivering RNA, including enhanced cellular targeting, improved stability, and reduced immunogenicity, thereby facilitating the efficient transfer of therapeutic RNA molecules into target cells. Therefore, it is crucial to summarize the applications of cancer therapy through exosome-loaded RNA. In this review, the formation process of exosomes is briefly introduced, followed by a summary of existing loading methods and a focus on therapeutic strategies for the delivery of five types of RNAs (such as siRNA, miRNA, mRNA, circRNA, and lncRNA). The review was concluded with deliberations on the key challenges and future outlooks of exosome-loaded RNA applications for cancer therapy.