PTEN C-terminal deletion causes genomic instability and tumor development

Area of Science:

• Molecular Biology
• Genetics
• Cancer Research

Background:

• The tumor suppressor PTEN (Phosphatase and Tensin homolog) plays a vital role in controlling cell growth and preventing cancer.
• While PTEN's N-terminal domain's function in regulating the PI3K/AKT pathway is known, its C-terminal domain's role remains less understood.
• Genomic instability is a hallmark of cancer, contributing to tumor initiation and progression.

Purpose of the Study:

• To investigate the function of the PTEN C-terminal domain in tumor suppression and genomic stability.
• To characterize a novel mouse model with a deletion of the PTEN C-terminal region.

Main Methods:

• Generation of a knockin mouse model (Pten(ΔC)) with a nonsense mutation deleting the PTEN C-terminal region.
• Analysis of tumor development, genomic instability, and common fragile site rearrangements in heterozygous Pten(ΔC) mice.
• Assessment of p53 activation and its downstream targets following PTEN C-terminal disruption.

Main Results:

• Heterozygous Pten(ΔC) mice spontaneously developed various tumors, including cancers and B cell lymphoma.
• Deletion of the PTEN C-terminal domain induced genomic instability and common fragile site rearrangements.
• PTEN C-terminal disruption led to the activation of p53 and its downstream targets.
• p53 depletion promoted metastasis but did not affect tumor initiation, suggesting a role in suppressing tumor progression.

Conclusions:

• The PTEN C-terminal domain is essential for maintaining genomic stability.
• PTEN C-terminal function is critical for suppressing tumorigenesis and tumor progression.
• The Pten(ΔC) mouse model provides valuable insights into the role of PTEN in cancer biology.