UXT, a novel MDMX-binding protein, promotes glycolysis by mitigating p53-mediated restriction of NF-κB activity

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• The tumor suppressor protein p53 is crucial in preventing cancer, but its basal activity's role remains unclear.
• Stress-induced p53 activation is well-studied, yet its role in normal cellular function and cancer prevention requires further investigation.

Purpose of the Study:

• To identify novel regulators of p53's basal activity.
• To investigate the role of UXT (a novel p53 inhibitor) in cancer, particularly sarcoma.
• To elucidate the molecular mechanisms by which UXT promotes tumorigenesis.

Main Methods:

• Identification and characterization of UXT as a p53 inhibitor.
• Analysis of TCGA database for UXT gene amplification in human cancers.
• In vitro and in vivo studies using sarcoma models to assess UXT's oncogenic potential.
• Screening of cellular pathways to understand UXT's downstream effects, including NF-κB and glycolysis.

Main Results:

• UXT binds to MDMX, inhibiting the basal activity of p53.
• UXT gene amplification is frequent in human sarcoma, correlating with rare p53 mutations.
• UXT promotes sarcoma cell proliferation and tumor progression by activating NF-κB and inducing glycolysis.
• UXT-expressing sarcoma cells exhibit increased sensitivity to glycolysis inhibitors.

Conclusions:

• UXT acts as an oncogene by suppressing basal p53 activity, thereby unleashing NF-κB and promoting glycolysis-driven carcinogenesis.
• The basal activity of p53 is critical for restricting NF-κB signaling.
• Targeting glycolysis presents a potential therapeutic strategy for UXT-driven cancers like sarcoma.