Anti-CXCR4 Single-Chain Variable Fragment Antibodies Have Anti-Tumor Activity

Area of Science:

• Oncology
• Immunology
• Biotechnology

Background:

• Monoclonal antibodies (mAbs) face limitations in cancer therapy due to their size.
• Human single-chain variable fragment (scFv) antibodies offer a smaller, potentially more effective alternative.
• Chemokine receptor CXCR4 is overexpressed in various cancers, driving tumor growth and metastasis, making it a key therapeutic target.

Purpose of the Study:

• To develop and characterize novel human scFv antibodies against the chemokine receptor CXCR4.
• To evaluate the efficacy of anti-CXCR4 scFvs in inhibiting cancer cell proliferation, migration, invasion, and inducing apoptosis.
• To assess the in vivo therapeutic potential of anti-CXCR4 scFvs in a preclinical cancer model.

Main Methods:

• Screening of a human scFv antibody library using a peptide from CXCR4 extracellular loop 2 (ECL2) via yeast two-hybrid.
• In vitro validation of scFv binding to CXCR4 and cancer cell lines (DU145, PC3, MDA-MB-231).
• Assessment of scFv effects on cancer cell proliferation, migration, invasion, and apoptosis.
• In vivo evaluation in a mouse xenograft model, including tumor growth inhibition and immunohistochemistry analysis.

Main Results:

• Three anti-CXCR4 scFvs were successfully isolated and demonstrated specific binding to CXCR4 and cancer cells.
• In vitro studies showed these scFvs significantly reduced cancer cell proliferation, migration, and invasion, while promoting apoptosis.
• In vivo studies confirmed that two scFvs inhibited tumor growth, reduced proliferation and angiogenesis, and increased apoptosis in a mouse xenograft model.

Conclusions:

• The developed anti-CXCR4 scFvs exhibit potent anti-cancer activity by inhibiting proliferation and tumor growth.
• These scFvs demonstrate potential as a novel therapeutic strategy for various CXCR4-expressing cancers.
• The small size and specific targeting of scFvs offer advantages over traditional monoclonal antibodies in cancer treatment.