Search PubMedSearch

Biomedical subjects

Yanfang Zhang

Publications and source records attributed to Yanfang Zhang.

2 recordsLinked to original sources

MicroRNA-181a-5p promotes papillary thyroid carcinoma progress via the PTEN/AKT pathway.

The objective of this investigation was to determine the expression profile and latent mechanism of microRNA-181a-5p (miR-181a-5p) in the genesis and progression of papillary thyroid cancer (PTC). MiR-181a-5p was discovered to be upregulated in PTC tissues and cells in this study, as confirmed by RT‒qPCR and The Cancer Genome Atlas database. Notably, in PTC patients, the miR-181a-5p level was linked to tumor size and thyroid capsule invasion. A series of experiments demonstrated that miR-181a-5p upregulation in PTC cells notably enhanced proliferation, motility, and invasion, whereas suppressing miR-181a-5p hindered these functions. Western blotting revealed that miR-181a-5p suppressed PTEN expression, boosting the activation of phosphorylated AKT (P-AKT). According to predictive bioinformatics research and luciferase reporter gene tests, miR-181a-5p may target a specific binding site on the PTEN 3'UTR. To sum up, this study indicated that miR-181a-5p promoted PTC progression through the PTEN/Akt pathway. This investigation reveals a potential mechanism for PTC progression and provides a foundation for clinical therapies.

MicroRNAs

NS2 induces an influenza A RNA polymerase hexamer and acts as a transcription to replication switch.

Genome transcription and replication of influenza A virus (FluA), catalyzed by viral RNA polymerase (FluAPol), are delicately controlled across the virus life cycle. A switch from transcription to replication occurring at later stage of an infection is critical for progeny virion production and viral non-structural protein NS2 has been implicated in regulating the switch. However, the underlying regulatory mechanisms and the structure of NS2 remained elusive for years. Here, we determine the cryo-EM structure of the FluAPol-NS2 complex at ~3.0 Å resolution. Surprisingly, three domain-swapped NS2 dimers arrange three symmetrical FluPol dimers into a highly ordered barrel-like hexamer. Further structural and functional analyses demonstrate that NS2 binding not only hampers the interaction between FluAPol and the Pol II CTD because of steric conflicts, but also impairs FluAPol transcriptase activity by stalling it in the replicase conformation. Moreover, this is the first visualization of the full-length NS2 structure. Our findings uncover key molecular mechanisms of the FluA transcription-replication switch and have implications for the development of antivirals.

Viral Nonstructural Proteins