Butein activates p53 in hepatocellular carcinoma cells via blocking MDM2-mediated ubiquitination

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Hepatocellular carcinoma (HCC) remains a significant global health challenge.
• Understanding molecular mechanisms underlying HCC progression is crucial for developing effective therapies.
• The role of the p53 tumor suppressor in HCC warrants further investigation.

Purpose of the Study:

• To investigate the effect of butein on p53 in hepatocellular carcinoma (HCC) cells.
• To elucidate the molecular mechanisms by which butein activates p53.
• To evaluate the therapeutic potential of butein for HCC management.

Main Methods:

• In vitro assays (MTS, clonogenic survival, reporter gene, flow cytometry, western blotting) were used to assess butein's antitumor activity, p53 transcriptional activity, and apoptosis induction.
• In vivo efficacy was determined using a xenograft model, with p53 expression analyzed by immunohistochemistry.
• Mechanism studies involved assessing MDM2-p53 interaction and p53 ubiquitination, alongside short-hairpin RNA knockdown experiments.

Main Results:

• Butein significantly inhibited HCC cell proliferation and survival, inducing apoptosis in a dose-dependent manner.
• Butein activated p53 transcriptional activity, increasing p53-targeted gene expression by blocking MDM2-p53 interaction and reducing p53 ubiquitination.
• p53 knockdown impaired HCC cell sensitivity to butein and reduced butein-induced apoptosis. In vivo studies confirmed butein's antitumor efficacy against HCC xenografts with increased p53 expression.

Conclusions:

• Butein exhibits potent antitumor activity in HCC by activating the p53 pathway.
• Butein's mechanism involves inhibiting MDM2-mediated p53 degradation, leading to apoptosis.
• Butein and its analogs hold therapeutic promise for managing hepatocellular carcinoma.