Targeting HAUSP in both p53 wildtype and p53-mutant tumors

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Mdm2 inhibition is a validated cancer therapy strategy, but limitations exist.
• Herpesvirus-Associated Ubiquitin-Specific Protease (HAUSP/USP7) deubiquitinase interacts with the p53/Mdm2 complex, regulating protein stability.
• Deubiquitinases (DUBs) play specific roles in protein stability regulation.

Purpose of the Study:

• To investigate the synergistic effects of HAUSP inhibitors and Nutlin-3 on p53 activation and cancer cell apoptosis.
• To explore HAUSP's role in targeting the N-Myc oncoprotein independently of p53.
• To evaluate the efficacy of novel HAUSP inhibitors against N-Myc in p53-mutant cancers.

Main Methods:

• Utilized inhibitors of HAUSP and Nutlin-3 in human cancer cell lines.
• Assessed p53 activation and p53-dependent apoptosis.
• Investigated HAUSP's interaction with and targeting of N-Myc.
• Compared the potency of novel HAUSP inhibitors versus existing ones in p53 mutant cells.

Main Results:

• HAUSP inhibitors and Nutlin-3 synergistically activate p53 and induce p53-dependent apoptosis in human cancer cells.
• HAUSP targets the N-Myc oncoprotein independently of p53.
• Newly developed HAUSP inhibitors are more effective than commercial ones at suppressing N-Myc and inhibiting growth in p53-mutant cancer cells.

Conclusions:

• HAUSP inhibitors offer a dual therapeutic strategy for cancer, acting through both p53-dependent and -independent pathways.
• Targeting HAUSP presents a promising approach for treating cancers with p53 mutations.
• Combined inhibition of HAUSP and Mdm2 enhances anti-cancer effects.