ABSTRACT Precise regulation of endoplasmic reticulum (ER) stress signaling in cancer remains a central challenge for nucleic acid–based therapeutics, largely due to their inability to discriminate ER‐stressed malignant cells and non‐stressed normal cells. Here we report an ER stress–responsive regulatory platform that couples the disease‐associated endoribonuclease activity of inositol‐requiring enzyme 1 (IRE1) to the conditional activation of DNA‐based effectors. By rationally grafting an X‐box binding protein 1 ( XBP1 )‐mimetic stem–loop “gate” onto canonical DNAzymes (IR‐Dz), we generate constructs that remain catalytically inert under basal IRE1 activity but are activated upon ER stress–induced IRE1 cleavage. The resulting IR‐Dz mediates cell‐selective c‐MYC silencing in ER‐stressed cancer cells, thereby attenuating ER stress while sparing normal counterparts. Redirecting IR‐Dz to IRE1 mRNA achieves the opposite outcome—self‐silencing of IRE1 and amplification of ER stress in tumor cells. This modular architecture can be adapted to other nucleic‐acid modalities, such as antisense oligonucleotides. By establishing IRE1 as an endogenous molecular trigger for spatially and contextually precise activation of nucleic acid effectors, our study introduces a general strategy for programmable, condition‐dependent gene regulation and dynamic modulation of ER stress signaling in cancer.
Sheng et al. (Tue,) studied this question.