Engineered mRNA System Delivers SMRTS for Cell-Selective Gene Expression

Publication date: Dec 14, 2025

But while vaccines succeed without needing to control which cells make the protein, cancer therapies demand far greater precision: the treatment must hit tumor cells while sparing healthy tissue. A new study titled -A tumor-selective mRNA system enables precision cancer treatment,” and published in Molecular Therapy, introduces a breakthrough approach building on lessons from mRNA vaccines. In proof‑of‑concept experiments in mice, the team created cancer‑specific variants-bcSMRTS for breast cancer and ccSMRTS for colon cancer-that demonstrated striking selectivity. These findings underscore the system’s ability to achieve high selectivity, activating therapeutic genes in tumors while sharply limiting activity in healthy organs such as the liver and spleen. The study highlights how SMRTS could overcome one of the biggest hurdles in mRNA therapeutics-off‑target toxicity-by engineering selectivity directly into the payload rather than relying solely on delivery vehicles. Researchers developed the selective modified RNA translation system (SMRTS), an engineered form of mRNA designed to activate therapeutic genes in certain cell populations. Therapeutic deployment of Pten ccSMRTS suppressed tumor growth by 45%, and combination with modRNA‑derived anti‑checkpoint inhibitor antibodies (modRNabs) resulted in up to 93% tumor inhibition,” the authors wrote.