Pseudouridine synthase 7 as a context-specific therapeutic target in cancer

Human pseudouridine synthase 7 (PUS7) catalyzes the isomerization of uridine to pseudouridine in RNA substrates. Although its catalytic region has been characterized, further studies are needed to clarify the mechanisms underlying its substrate recognition and specificity. PUS7 promotes tumor progression in glioblastoma, pancreatic adenocarcinoma, neuroblastoma, hepatocellular carcinoma, and colorectal cancer by altering RNA stability, translational fidelity, and splicing, ultimately regulating key oncogenic processes such as cell proliferation, self-renewal, metabolic reprogramming, and stress responses. Additionally, PUS7 can promote tumor progression through noncatalytic mechanisms, as observed in colorectal cancer, where it forms protein-protein complexes that activate oncogenic signaling pathways. Conversely, PUS7 exhibits tumor-suppressive functions in gastric carcinoma and papillary thyroid carcinoma by targeting mRNAs and miRNAs that regulate gene expression linked to reduced tumor aggressiveness. These findings indicate that PUS7 may represent a context-dependent therapeutic target and underscore the need for further research to clarify the molecular basis of its effects in cancer. Such knowledge may guide the development of new therapeutic strategies for PUS7-driven tumors. SIGNIFICANCE STATEMENT: Recent studies reveal that dysregulated pseudouridine synthase activity contributes to the progression of malignancies such as glioblastoma, pancreatic adenocarcinoma, neuroblastoma, colorectal cancer, and hepatocellular carcinoma. Here, we review the pseudouridine synthase's structure-function relationships and context-specific activities. The evidence discussed will help the development of selective therapeutic strategies targeting RNA modification pathways.