Efficient expression of in vitro–transcribed (IVT) mRNA is a key factor determining the therapeutic efficacy of mRNA-based treatments. However, exogenously delivered mRNA can activate innate immune signaling pathways that limit protein translation. Tripartite motif-containing protein 25 (TRIM25) is an E3 ubiquitin ligase known to participate in antiviral innate immune responses.

In this study, we investigated whether TRIM25 modulates the translation efficiency of IVT mRNA in cancer cells. TRIM25 expression was transiently silenced using small interfering RNA (siRNA) in HeLa cells, followed by transfection of IVT p53 mRNA generated in our laboratory as a model transcript to evaluate translation efficiency.

Western blot analysis revealed that p53 protein expression was relatively low in cells transfected with IVT p53 mRNA alone. In contrast, cells treated with siTRIM25 exhibited markedly increased p53 protein levels compared with control cells. These results suggest that depletion of TRIM25 enhances translation of exogenously delivered IVT mRNA.

Collectively, our findings suggest that TRIM25 may act as an intracellular innate immune–related factor that limits the efficient translation of IVT mRNA. Modulation of TRIM25 activity may therefore represent a potential strategy to overcome intracellular translation barriers and improve the therapeutic efficacy of mRNA-based anticancer approaches.