The Protein Tyrosine Phosphatase Activity of Eyes Absent Contributes to Tumor Angiogenesis and Tumor Growth

Area of Science:

• Molecular Oncology
• Cancer Biology
• DNA Damage Response

Background:

• Cellular survival and proliferation under stress depend on DNA damage repair capacity.
• Histone protein H2AX is central to DNA repair complex assembly, preventing cell death.
• Eyes Absent (EYA) proteins regulate H2AX by dephosphorylating its terminal tyrosine residue.

Purpose of the Study:

• To investigate the distinct roles of host vascular endothelial cell EYA and tumor cell EYA in tumor growth.
• To evaluate the therapeutic potential of targeting EYA in cancer treatment.

Main Methods:

• Genetic manipulation (gene deletion) to study EYA3 function in host endothelial and tumor cells.
• Chemical biology approach using a specific EYA tyrosine phosphatase inhibitor.
• Xenograft models to assess tumor growth, angiogenesis, and proliferation.

Main Results:

• Deletion of Eya3 in host endothelial cells significantly reduced tumor angiogenesis and overall tumor growth.
• Deletion of Eya3 in tumor cells decreased tumor cell proliferation and growth, without impacting angiogenesis.
• A chemical inhibitor targeting EYA phosphatase activity effectively inhibited both tumor angiogenesis and tumor growth.

Conclusions:

• EYA3 plays a dual role in tumor progression, affecting both tumor cell-autonomous growth and tumor angiogenesis.
• Targeting EYA phosphatase activity offers a promising therapeutic strategy for simultaneously inhibiting tumor vasculature and tumor cells.
• This dual-targeting approach may overcome resistance mechanisms associated with conventional anti-angiogenic therapies.