Discovery of HSPG2 (Perlecan) as a Therapeutic Target in Triple Negative Breast Cancer

Area of Science:

• Oncology
• Immunology
• Molecular Biology

Background:

• Advances in breast cancer treatment have improved survival rates.
• Metastatic triple negative breast cancer (TNBC) has limited treatment options due to a lack of unique markers.
• Identifying novel targets is crucial for developing effective TNBC therapies.

Purpose of the Study:

• To develop novel human antibodies targeting metastatic TNBC.
• To identify the specific cell surface antigen recognized by these antibodies.
• To evaluate the therapeutic potential of targeting this antigen in TNBC.

Main Methods:

• Phage display-based whole cell biopanning was used to generate antibodies.
• Domain 1 of HSPG2 (perlecan) was identified as the target antigen.
• Immunohistochemistry, in vivo tumor growth inhibition assays, and in vitro cytotoxicity assays were performed.

Main Results:

• Two human antibodies were developed that bind to metastatic TNBC cells.
• HSPG2 (perlecan) was identified as the cognate cell surface antigen.
• Higher HSPG2 expression in patients correlated with poorer TNBC survival.
• Antibody treatment demonstrated efficacy in mice, suggesting NK cell-mediated cytotoxicity.

Conclusions:

• HSPG2 is a promising cell surface target for metastatic TNBC.
• HSPG2-targeted antibodies show potential as a novel therapeutic strategy for TNBC.
• Further research into antibody-dependent cell-mediated cytotoxicity mechanisms is warranted.