从核蛋白、PEST 的结构，功能特点，到PCNP与肿瘤发生
A 300-Word Mini Review: PCNP Structure, Function and Biomedical Significance in Liver Cancer
PEST-containing nuclear protein (PCNP) is a short-lived nuclear regulatory protein characterized by exclusive nuclear localization and dual conserved PEST sequences, which dominate its protein stability and biological activity. As a core post-translational modification motif rich in proline, glutamic acid, serine and threonine, the PEST domain mediates ubiquitin-proteasome degradation under physiological conditions, maintaining low basal PCNP expression and hepatocyte homeostasis. In the hepatocellular carcinoma (HCC) microenvironment, abnormal phosphorylation of PEST sequences blocks NIRF-dependent ubiquitination, prolongs PCNP half-life, and causes excessive nuclear accumulation of PCNP, driving HCC malignant progression.
Structurally dependent functional changes enable PCNP to serve as a key regulator in HCC pathogenesis. Aberrant nuclear PCNP accelerates G1/S cell cycle transition, promotes unlimited proliferation of hepatoma cells, and facilitates epithelial-mesenchymal transition to enhance tumor invasion and metastasis. Additionally, dysregulated PCNP inhibits HCC cell apoptosis and reprograms tumor glucose metabolism, further aggravating malignant phenotypes.
Biomedically, PCNP exhibits great translational value in liver cancer research. Its distinct differential expression between HCC tumor and adjacent tissues is closely correlated with TNM staging and patient prognosis, qualifying PCNP as a novel diagnostic and prognostic biomarker. Targeting the PEST sequence to restore PCNP degradation provides a promising strategy for HCC precision therapy. Current studies remain limited in upstream regulatory mechanisms and targeted drug development. Further exploration of PCNP PEST structural modification and nuclear signaling networks will advance its clinical application in HCC diagnosis and targeted treatment.
