23 June 2021
Vol 13, Issue 599

About The Cover

Cover image expansion

ONLINE COVER Tumor Suppressor Reactivation. This image shows messenger RNA (mRNA)-loaded nanoparticles (red) that have escaped endolysosomes (green) and are present in the cytosol of prostate cancer cells. Nuclei are in blue. Reactivation of tumor suppressors, such as phosphatase and tensin homolog deleted on chromosome 10 (PTEN), may be a strategy by which tumor microenvironments can be converted from immune-suppressive to proinflammatory. Lin et al. delivered PTEN-encoding mRNA to PTEN-deficient melanoma or prostate cancer tumors in mice using nanoparticles. This restored PTEN protein expression and promoted antitumor immune responses in both tumor types, which was further enhanced by the addition of immune checkpoint blockade. Thus, nanoparticle-mediated delivery of tumor suppressor mRNA may be a strategy to improve antitumor immunity. [CREDIT: LIN ET AL./SCIENCE TRANSLATIONAL MEDICINE]